Innovation is the result of the commitment to research and the continued pursuit of excellence. Constant improvement, in both detection and treatment, is key to being able to face all the challenges arthroscopic surgery puts forth. True to these principles, Equilae is now a leading unit in using the most advanced techniques and in quality of care.
Innovation is the result of the commitment to research and the continued pursuit of excellence.
This has earned us the recognition of the foremost organizations, participation in the most prestigious journals and in scientific discussion forums and lectures. That recognition has it possible for us to transmit our contributions to the scientific community.
Does anatomic single-bundle ACL reconstruction using hamstring autograft produce anterolateral meniscal root tearing? Abstract Descargar PDF Abstract
To determine if tibial tunnel reaming during anatomic single-bundle anterior cruciate ligament (ACL) reconstruction using hamstring autograft can result in anterolateral meniscal root injury, as diagnosed by magnetic resonance imaging (MRI).
A case series of 104 primary anatomic single-bundle ACL reconstructions using hamstring autograft was retrospectively reviewed. Pre- and post-operative (>1 year) MRIs were radiologically evaluated for each patient, with a lateral meniscus extrusion > 3 mm at the level of the medial collateral ligament midportion on a coronal MRI, to establish anterolateral meniscal root injury.
No patients presented radiological findings of anterolateral meniscal root injury in this case series.
Examining a single-bundle ACL reconstruction technique using hamstring autograft that considered tibial tunnel positioning in the center of the tibial footprint, this case series found no evidence of anterolateral meniscal root injury in patient MRIs, even more than 1-year post-operation.
J Exp Orthop. 2017 Dec;4(1):17. doi: 10.1186/s40634-017-0093-5. Epub 2017 May 22.
Lateral Capsular Fixation: An Implant-Free Technique to Prevent Meniscal Allograft Extrusion Abstract Descargar PDF Abstract
Although several surgical techniques have been described to perform meniscal allograft transplantation with good clinical results and although different methods of capsular stabilization can be found in the literature, there is no standard surgical technique to prevent a common complication in the most of series: the tendency to a radial displacement or extrusion of the transplanted menisci. We present a simple, reproducible, and implant-free technique to perform a lateral capsular fixation (capsulodesis) at the time of only the soft-tissue fixation technique of meniscal allograft transplantation in an effort to reduce or prevent the risk of graft extrusion. Using a minimum of two 2.4-mm tunnels drilled from the contralateral side of the tibia with the help of a regular tibial anterior cruciate ligament guide, a capsular attachment to the lateral tibial plateau is obtained.
Arthrosc Tech. 2017 Mar 6;6(2):e269-e274. doi: 10.1016/j.eats.2016.09.032. eCollection 2017 Apr.
What is the most reproducible classification system to assess tibial plateau fractures? Abstract Descargar PDF Abstract
Traditional classification systems for tibial plateau fractures (TPF) are based on simple radiographs, and intra- and inter-observer variability is low. The aim was to assess intra- and inter-observer variability using traditional systems and some recently described classification systems of TPF in the interpretation of standard radiographs and bidimensional (2D) and tridimensional (3D) computed tomography (CT).
We studied all patients at two centres who underwent TPF surgery over a three-year period. Demographic data (age, sex, BMI) and mechanism of injury were recorded. Four observers classified each TPF according to the Schatzker, AO, Luo, modified Duparc and Khan classification systems. We calculated intra- and inter-observer variability using the Kappa test.
A total of 112 (71 males) patients were included. Mean age was 47.1 years (range 21-86) and mean BMI was 25.2 ± 3.6. Intra- and inter-observer variability was 0.95 and 0.62 for AO, 0.87 and 0.65 for Schaztker, 0.86 and 0.73 for Luo, 0.56 and 0.37 for the modified Duparc, and 0.43 and 0.25 for Khan classifications.
Although previous training could be needed, AO, Schatzker and Luo classifications showed a good reproducibility of TPF assessment from a combination of standard radiographs and 2D and 3D CT images. The results using the Modified Duparc and Khan classifications were less favourable and their use is not therefore recommended.
Int Orthop. 2017 Jun;41(6):1251-1256. doi: 10.1007/s00264-017-3462-x. Epub 2017 Apr 13.
Femoral Tunnel Drilling Angles for Posteromedial Corner Reconstructions of the Knee Abstract Descargar PDF Abstract
Purpose: To determine the best angle to drill the femoral tunnels of the superficial medial collateral ligament (sMCL) and posterior oblique ligament (POL) with concomitant posterior cruciate ligament (PCL) reconstruction to avoid either short tunnels or tunnel collisions. Methods: Eight cadaveric knees were studied. Double-bundle PCL femoral tunnels were arthroscopically drilled. Drilling of the sMCL and POL tunnels was performed in 4 different combinations of 0 and 30 axial (anteriorly directed) and coronal (proximally directed) angulations. Specimens were scanned with computed tomography to document the relations of the sMCL and POL tunnels to the intercondylar notch and PCL tunnels. A minimum tunnel length of 25 mm was required. Results: When the sMCL femoral tunnel was drilled at 0 axial and 30 coronal (proximally directed) angulations or 30 axial (anteriorly directed) and 0 coronal angulations, the risk of tunnel collision with the PCL tunnels increased in comparison with the remaining evaluated angulations (P < .001). No POL tunnels collided with either PCL tunnel bundle with the exception of tunnels drilled at 0 axial and 30 coronal (prox- imally directed) angulations, which did so in 3 of 8 cases (P < .001). The minimum required tunnel length was obtained in all the sMCL and POL tunnels (P < .001 and P 1⁄4 .02, respectively). However, some of those angled at 0 on the axial plane violated the intercondylar notch. Conclusions: When one is performing posteromedial reconstructions with concomitant PCL procedures, the sMCL and POL femoral tunnels should be drilled anteriorly and proximally at both 30 axial and 30 coronal angulations. The POL femoral tunnel may also be angled 0 in the coronal plane. Tunnels at 0 axial angulations showed a shorter distance to the intercondylar notch and a higher risk of collision with the PCL tunnels. Clinical Relevance: Specific drilling angles are necessary to avoid short tunnels or collisions between the drilled tunnels when sMCL and POL femoral tunnels are placed with concomitant PCL reconstruction.
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 31, No 9 (September), 2015: pp 1764-1771
The anatomy and isometry of a quasi‐anatomical reconstruction of the medial patellofemoral ligament Abstract Descargar PDF Abstract
Purpose To describe the anatomy of the medial patel- lofemoral ligament (MPFL) and its relationship to the Adductor Magnus (AM) tendon as well as the behaviour exhibited in length changes during knee exion.
Methods Ten cadaveric knees were dissected. The length from the superior and inferior patellar origin of the MPFL to its femoral insertion was measured at different degrees of knee exion (0°, 30°, 60°, 90° and 120°). The same measures were made from both patellar origins of the MPFL up to the femoral insertion of the AM. The distance between the insertion of the AM and the Hunter canal was also measured.
Results In general, isometry up to 90° was seen in all measures of the MPFL and those of the AM. The most iso- metric behaviour was seen in 2 measures: the length of the AM femoral insertion up to the inferior origin of the MPFL on the patella and the length of the femoral insertion of the MPFL up to the inferior origin of the MPFL on the patella. Similar behaviour was seen regardless of the anatomical or quasi-anatomical femoral point of attachment (n.s.). The distance from the AM tendon to the Hunter canal had a mean value of 78.6 mm (SD 9.4 mm).
Conclusion The behaviour exhibited during the changes in the length of the anatomical femoral footprint of the MPFL and the AM is similar. Neurovascular structures were not seen at risk. This is relevant in the daily clinical practice since the AM tendon might be a suitable point of insertion for MPFL reconstruction.
Knee Surg Sports Traumatol Arthroscopy, November 2015
An Evaluation of the Association Between Radiographic Intercondylar Notch Narrowing and Anterior Cruciate Ligament Injury in Men: The Notch Angle Is a Better Parameter Than Notch Width Abstract Descargar PDF Abstract
Purpose: To evaluate the association of anterior cruciate ligament (ACL) injuries with the intercondylar notch angle and notch width in male patients. The secondary purpose was to evaluate the association of these injuries with other novel morphologic parameters. Methods: Male patients undergoing primary ACL reconstruction between 2010 and 2013 for injury through noncontact mechanisms with preoperative magnetic resonance imaging were compared with an age- matched control group of male patients (patients who underwent knee operations other than ACL reconstruction) regarding the following magnetic resonance imagingeassessed parameters: intercondylar notch angle, width, and depth; condylar width; medial/lateral condylar widths; medial/lateral posterior tibial plateau slopes; anterior sagittal tibial slope (corresponding to the level of the tibial ACL footprint); coronal tibial slope; and angle between the Blumensaat line and anterior tibial slope. Results: In both the coronal and axial planes, patients with ACL injury had a significantly lower intercondylar notch angle (P < .001 and P 1⁄4 .008, respectively) than the control group, but there were no significant between-group differences for intercondylar notch width (P 1⁄4 .9 and P 1⁄4 .97, respectively). In the sagittal plane, patients with ACL injury had significantly higher medial (P < .001) and lateral (P 1⁄4 .02) posterior tibial slopes, a significantly lower anterior tibial slope (P 1⁄4 .01), and a significantly higher angle between the Blumensaat line and anterior tibial slope (P 1⁄4 .02) than the control group. Conclusions: Narrowing of the intercondylar notch may be associated with ACL injury in male patients. However, the intercondylar notch angle may be a better parameter to evaluate notch narrowing and its potential association with ACL injuries compared with the notch width. The association between the angle formed by the Blumensaat line and anterior tibial slope and ACL injuries in male patients needs more investigation. This study further suggests that increased posterior tibial slope may be associated with ACL injury in male patients. Level of Evidence: Level III, case-control study.
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 31, No 10 (October), 2015: pp 2004-2013
A Novel Association between Femoroacetabular Impingement and Anterior Knee Pain Abstract Descargar PDF Abstract
Background. For a long time it has been accepted that the main problem in the anterior knee pain (AKP) patient is in the patella. Currently, literature supports the link between abnormal hip function and AKP. Objective. Our objective is to investigate if Cam femoroacetabular impingement (FAI) resolution is related to the outcome in pain and disability in patients with chronic AKP recalcitrant to conservative treatment associated with Cam FAI. Material and Methods. A retrospective study on 7 patients with chronic AKP associated with FAI type Cam was performed. Knee and hip pain were measured with the visual analogue scale (VAS), knee disability with the Kujala scale, and hip disability with the Nonarthritic Hip Score (NAHS). Results. e VAS knee pain score and VAS hip pain score had a signi cant improvement postoperatively. At nal follow-up, there was signi cant improvement in all functional scores (Kujala score and NAHS). Conclusion. Our nding supports the link between Cam FAI and AKP in some young patients. Assessment of Cam FAI should be considered as a part of the physical examination of patients with AKP, mainly in cases with pain recalcitrant to conservative treatment.
Hindawi Publishing Corporation Pain Research and Treatment, Volume 2015, Article ID 937431, 4 pages
Managing septic arthritis after knee ligament reconstruction Abstract Descargar PDF Abstract
Purpose Joint infection after anterior cruciate ligament (ACL) reconstruction is uncommon but has potentially serious consequences for the graft and articular carti- lage. Most recently published series are in agreement that an urgent arthroscopic washout and antibiotic treat- ment are mandatory to preserve both graft and cartilage. However, several questions have not as yet been touched upon.
Methods We performed a literature review to assess the most interesting series published about this issue. Results In this review, a management protocol is first presented that discusses the different diagnostic param- eters to consider and surgical and antibiotic treatment suggested according to the literature. Outcomes pub- lished in different series are also discussed.
International Orthopaedics (SICOT) (August 2015)
Topical and intravenous tranexamic acid reduce blood loss compared to routine hemostasis in total knee arthroplasty: a multicenter, randomized, controlled trial Abstract Descargar PDF Abstract
Introduction Tranexamic acid (TXA) is becoming widely used in orthopedic surgery to reduce blood loss and transfusion requirements, but consensus is lacking regard- ing the optimal route and dose of administration. The aim of this study was to compare the efficacy and safety of topical and intravenous routes of TXA with routine he- mostasis in patients undergoing primary total knee arthro- plasty (TKA).
Materials and methods We performed a randomized, multicenter, parallel, open-label clinical trial in adult pa- tients undergoing primary TKA. Patients were divided into three groups of 50 patients each: Group 1 received 1 g topical TXA, Group 2 received 2 g intravenous TXA, and Group 3 (control group) had routine hemostasis. The pri- mary outcome was total blood loss. Secondary outcomes were hidden blood loss, blood collected in drains, trans- fusion rate, number of blood units transfused, adverse events, and mortality.
Results One hundred and fifty patients were included. Total blood loss was 1021.57 (481.09) mL in Group 1, 817.54 (324.82) mL in Group 2 and 1415.72 (595.11) mL in Group 3 (control group). Differences in total blood loss between the TXA groups and the control group were clinically and statistically significant (p \ 0.001). In an exploratory analysis differences between the two TXA groups were not statistically significant (p = 0.073) Seventeen patients were transfused. Transfusion require- ments were significantly higher in Group 3 (p = 0.005). No significant differences were found between groups re- garding adverse events.
Conclusion We found that 1 g of topical TXA and 2 g of intravenous TXA were both safe strategies and more ef- fective than routine hemostasis to reduce blood loss and transfusion requirements after primary TKA.
Archives of Orthopaedic and Trauma Surgery, May 2015
Pressure algometry is a useful tool to quantify pain in the medial part of the knee: An intra- and inter-reliability study in healthy subjects Abstract Descargar PDF Abstract
Purpose: Pain quantification is essential for diagnostic and pain monitoring purposes in disorders around the knee. Pressure algometry is a method described to determine pressure pain threshold (PPT) by apply- ing controlled pressure to a given body point. The purpose of this study was to determine the reliability of this method when it was applied to the medial part of the proximal tibia metaphysis and to evaluate the PPT levels between genders.
Methods: Fifty healthy (mean age; 46.9) volunteers were recruited, 25men and 25women. Pressure algometry was applied to a 1 cm2 -probe area on the medial part of the knee by 2 raters. Intra- and inter- class correlation (ICC) was obtained and differences between genders were evaluated. Bland-Altman plots were performed to evaluate the variability of the measures.
Results: The mean values of PPT obtained by rater1 and 2 were 497.5Kpa and 489Kpa respectively The intrarater reliability values (95% IC) for rater 1 and 2 were 0.97 (0.95–0.98) and 0.84 (0.73–0.90) respectively. With regard to interrater reliability, the ICC (95% IC) for the first measurement was 0.92 (0.87–0.95) and 0.86 (0.78–0.92) for the second one. Women showed significant lower values of PPT than men. The Bland-Altmand plots showed excellent agreement.
Conclusions: Pressure algometry has excellent reliability when it is applied to the medial part of the proximal metaphysis of the tibia. Women have lower values of PTT than men. The high reliability of the PA in an individual volunteer makes it a more valuable tool for longitudinal assessment of a given patient than for comparison between them.
Level of evidence: Level III. Prospective study
El Sevier, Orthopaedics & Traumatology: Surgery & Research, March 2015
Arthroscopic Treatment of Hip Chondral Defects With Bone Marrow Stimulation and BST-CarGel Abstract Descargar PDF Abstract
Abstract: Microfracture, the current standard of care for the treatment of non-degenerative chondral lesions in the hip joint, is limited by the poor quality of the filling fibrocartilaginous tissue. BST-CarGel (Piramal Life Sciences, Laval, Quebec, Canada) is a chitosan-based biopolymer that, when mixed with fresh, autologous whole blood and placed over the previously microfractured area, stabilizes the blood clot and enhances marrow-triggered wound-healing repair pro- cesses. BST-CarGel has been previously applied in the knee, with statistically significant greater lesion filling and superior repair tissue quality compared with microfracture treatment alone. In this report we describe the application of BST- CarGel for the arthroscopic treatment of hip chondral lesions. Our preliminary data suggest that our BST-CarGel pro- cedure provides high-quality repair tissue and therefore may be considered a safe, cost-efficient therapeutic choice for the treatment of hip chondral defects.
Arthroscopy Techniques, Vol 4, No 1 (February), 2015: pp e29-e33
An experimental study of muscular injury repair in a mouse model of notexin-induced lesion with EPI® technique Abstract Descargar PDF Abstract
Background: The mechanisms of muscle injury repair after EPI® technique, a treatment based on electrical stimulation, have not been described. This study determines whether EPI® therapy could improve muscle damage.
Methods: Twenty-four rats were divided into a control group, Notexin group (7 and 14 days) and a Notexin + EPI group. To induce muscle injury, Notexin was injected in the quadriceps of the left extremity of rats. Pro-inflammatory interleukin 1-beta (IL-1beta) and tumoral necrosis factor-alpha (TNF-alpha) were determined by ELISA. The expression of receptor peroxisome gamma proliferator activator (PPAR-gamma), vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor-1 (VEGF-R1) were determined by western-blot.
Results: The plasma levels of TNF-alpha and IL-1beta in Notexin-injured rats showed a significant increase compared with the control group. EPI® produced a return of TNF-alpha and IL-1beta values to control levels. PPAR-gamma expression diminished injured quadriceps muscle in rats. EPI® increased PPAR-gamma, VEGF and VEGF-R1 expressions. EPI® decreased plasma levels of pro-inflammatory TNF-alpha and IL-1beta and increased anti-inflammatory PPAR-gamma and proangiogenic factors as well as VEGF and VEGF-R1 expressions.
Conclusion: The EPI® technique may affect inflammatory mediators in damaged muscle tissue and influences the new vascularization of the injured area. These results suggest that EPI® might represent a useful new therapy for the treatment of muscle injuries. Although our study in rats may represent a valid approach to evaluate EPI® treatment, studies designed to determine how the EPI® treatment may affect recovery of injury in humans are needed.
BMC Sports Science, Medicine, and Rehabilitation (2015) 7:7
Alta recidiva y buenos resultados funcionales tras la resección artroscópica de la sinovitis villonodular pigmentaria de la rodilla Abstract Descargar PDF Abstract
Introducción: La sinovitis villonodular pigmentaria (SVP) es un trastorno de la proliferación sinovial de etiología incierta, con un tratamiento controvertido. El objetivo del estudio es valo- rar los resultados funcionales y la tasa de recurrencia en una serie de pacientes diagnosticados de SVP de rodilla, tanto en su forma difusa como en su forma localizada, tratados mediante resección artroscópica.
Material y métodos: Estudio retrospectivo de 24 pacientes diagnosticados por resonancia mag- nética de SVP local/difusa entre 1996 y 2011. Se trataron 11 casos de forma localizada y 13 de forma difusa. Tras un seguimiento medio de 60 meses (rango: 34-204). Se intervinieron mediante sinovectomía artroscópica y se valoraron funcionalmente en el postoperatorio con los test IKDC, WOMET, Kujala y Tegner. Resultados: Ocho pacientes afectados de SVP difusa recidivaron (un 61,5% de las formas difu- sas). De ellos 2 requirieron radioterapia, uno cirugía abierta por afectación extraarticular y 5 nueva resección artroscópica sin detectarse posteriormente nueva recidiva. En 6 pacientes se observaron lesiones asociadas (en 3 meniscopatía y en 3 lesiones condrales). No hubo recidivas en la forma localizada. El IKDC mejoró de media 30,6 puntos, el WOMET 37,4 puntos y Kujala 34,03 puntos.
Revista Española de Cirugía Ortopédica y Traumatología. Traumatol. 2015.
Autograft soaking in vancomycin reduces the risk of infection after anterior cruciate ligament reconstruction Abstract Descargar PDF Abstract
Purpose To determine whether the bathing of an anterior cruciate ligament (ACL) autograft in vancomycin reduces the rate of infection following an ACL reconstruction. Methods Retrospective analysis of all ACL reconstruc- tions over an 8-year period in two University Hospitals. In the initial 4-year period, all patients were operated on under classical antibiotic intravenous prophylaxis (group 1). Over the last 4-year period, this prophylaxis was supplemented with presoaking of the autograft (group 2). Presoaking was performed with sterile gauze previously saturated with a vancomycin solution (5 mg/ml).
Results There were 810 and 734 patients in group 1 and 2, respectively. Fifteen cases of knee joint infections were identified in the series (0.97 %). All of these infec- tions occurred in group 1, representing a rate of infection of 1.85 % in comparison with 0 % in group 2 (p < 0.001). Conclusions Autograft presoaking with vancomy- cin in combination with classical intravenous antibiotic prophylaxis reduced the rate of knee joint infection follow- ing an ACLR in comparison with antibiotic prophylaxis alone. This technique could be of relevance in daily clinical practice to prevent infection after ACLR. Level of evidence Case control study, retrospective com- parative study, Level III.
European Society of Sports Traumatology, Knee Surgery, Arthroscopy, November 2014
Sealing of the intramedullar femoral canal in a TKA does not reduce postoperative blood loss: A randomized prospective study Abstract Descargar PDF Abstract
Background: Sealing of the femoral canal, usually with autologous bone, is a surgical procedure that is often per- formed during TKA surgery to decrease blood loss in the postoperative period. However, evidence as to the effec- tiveness of this surgical procedure is not conclusive. The objective of this study was to assess the effectiveness of this surgical action in reducing postoperative blood loss and the blood transfusion rate. Methods: A randomized prospective study that included 201 TKAs divided into three groups (67 in each one) was carried out. The three groups were; A) bone graft sealing, B) cement sealing and C) unsealed canal. All groups were comparable with regard to pre and intra-operative data. The haemoglobin decrease at 2, 24 and 72 h was compared to the preoperative haemoglobin value. Subsequently, blood drainage at 12 and 24 h and the rate of blood transfusion were also assessed. The different complications that arose were reported. Results: No statistical differences were obtained with regard to blood drainage at 12 h (p = 0.102) and 24 h (p = 0.542), the haemoglobin value decrease at 72 h (p = 0.95) and the number of blood transfusions (p = 0.597) in the three groups studied. Conclusion: There was no significant difference, whether sealing the femoral canal with a bone graft, cement or when it was left unsealed, in decreasing blood loss or blood transfusion requirements in the postoperative period. Level of evidence: Therapeutic type I.
The Knee. Volume 21. Issue 4. August 2014. Pages 853-857
Partial meniscus substitution with a polyurethane scaffold does not improve outcome after an open-wedge high tibial osteotomy Abstract Descargar PDF Abstract
Purpose The aim of the study was to determine whether medial meniscal substitution with a polyurethane scaf- fold (Actifit®) improves the outcome of medial meniscal- deficient varus knees undergoing open-wedge high tibial osteotomy.
Methods Sixty patients with symptomatic varus knees those who underwent open-wedge high tibial osteotomies were prospectively studied. In 30 patients, the medial meniscus was left with a defect larger than 25 mm (Group M). An Actifit® device was implanted (Group A) in the remaining 30 patients. Patients were functionally evaluated with WOMET, IKDC and VAS. Patient satisfaction was graded from 0 (not satisfied) to 4 (very satisfied).
Results Both groups were comparable preoperatively. They had similar follow-up periods (31.2 months; range 24–47.5; n.s.). WOMET improved a mean of 53.4 ± 8.4 and 42.4 ± 17.2 points in Groups M and A, respectively (p = 0.002). IKDC improved a mean of 56.7 ± 12 and 50.3 ± 15.6 points in Groups M and A, respectively (n.s.). VAS dropped 5.9 ± 2.1 and 4.7 ± 2.8 points in Groups M and A, respectively (p = 0.006). Patient satisfaction aver- aged 3.3 ± 0.8 and 3.3 ± 1 in Groups M and A, respec- tively (n.s.).
Conclusions Patients with symptomatic varus knees were treated with open-wedge high tibial osteotomies, and a meniscectomy was improved more at short-term follow- up in most of the evaluated functional scores than those patients with concomitant implantation of a medial Acti- fit® implant. However, there was no difference in terms of patient satisfaction with the procedure. Based on the short- term functional results of this study, no data were provided to support medial meniscal substitution with a polyure- thane scaffold when an open-wedge high tibial osteotomy is being performed.
Level of evidence Prospective comparative study, Level II.
Knee Surg Sports Traumatol Arthrosc, July 2014
The magnetic resonance aspect of a polyurethane meniscal scaffold is worse in advanced cartilage defects without deterioration of clinical outcomes after a minimum two-year follow-up Abstract Descargar PDF Abstract
Background: Meniscal scaffolding is thought to provide functional improvement and to prevent cartilage degen- eration. Advanced chondral injuries might damage the scaffold structural properties.
Objective: To evaluate the influence of different degrees of articular chondral injuries on the imaging aspect of a polyurethane meniscal scaffold (Actifit®).
Methods: Fifty-four patients operated on with an Actifit® were studied. The status of the articular cartilage in the involved compartment was classified according to ICRS. The characteristics of the implant were evaluated in MRI with the Genovese score. Functional scores included WOMET, IKDC and Kujala scores. The Genovese score was correlated with the degree of chondral injury and functional results.
Results: The mean follow-up was 39 months (range 25–63). Additional procedures were performed in 69.5%. There were 19 patients without chondral injuries and 14 with grade 1, 10 with grade 3 and eight with grade 4 chondral lesions. The morphology and size of the implant on MRI scanning were worse with a higher degree of chondral injury (p = 0.023). WOMET, IKDC and Kujala improved from 36.2 SD ± 7.6, 32.3 SD ± 13.5 and 39.2 SD ± 8.1 to 75.8 SD ± 12.9 (p = 0.02), 75.5 SD ± 15.4 (p = 0.03) and 85.6 SD ± 13.4 (0.042), respectively. There was no relationship between the severity of chondral injury and functional scores.
Conclusions: Patients without chondral injuries showed a better MRI aspect of the polyurethane scaffold in terms of size and morphology. By optimizing biomechanics, in particular the implantation of a meniscal substitute, significant pain relief and functional improvement were observed after a minimum two-year follow-up.
Level of evidence: Therapeutic case series; level 4.
The Knee, May 2014
Primary lipoma arborescens of the knee may involve the development of early osteoarthritis if prompt synovectomy is not performed Abstract Descargar PDF Abstract
Background Primary lipoma arborescens (LA) is a rare, benign intra-articular hyperplastic tumor that has been associated with osteoarthritis (OA). The aim of this study was to determine whether prompt synovectomy could avoid progressive joint degeneration in cases of primary LA of the knee.
Materials and methods A review of currently available literature about the disease was carried out. The clinical, histological and radiological records of a series of nine knees with primary LA diagnosed and treated between 2002 and 2012 were retrospectively reviewed. Eight of the knees had histological confirmation of LA and none had evidence of condropathy on the initial magnetic resonance image or degenerative changes at the initial radiographic examination.
Results At the final follow-up no evidence of OA was found in the three knees that underwent synovectomy when symptoms did not last more than 1 year. The five knees in which synovectomy was delayed developed progressive joint degeneration.
Conclusion In this series, primary LA of the knee involved the development of early osteoarthritis when prompt synovectomy was not performed. Timely syno- vectomy is strongly recommended, if not mandatory. Level of evidence IV.
Magnetic resonance evaluation of TruFit plugs for the treatment of osteochondral lesions of the knee shows the poor characteristics of the repair tissue Abstract Abstract
Background: Treatment of osteochondral lesions of the knee with synthetic scaffolds seems to offer a good surgical option preventing donor site morbidity. The TruFit plug has frequently been shown to not properly incorporate into.
Objective: To evaluate the relationship between MRI findings and functional scores of patients with osteochondral lesions of the knee treated with TruFit .
Methods: Patients were evaluated with MOCART score for magnetic resonance imaging assessment of the repair tissue. KOOS, SF-36 and VAS were used for clinical evaluation. Correlation between size of the treated chondral defect and functional scores was also analyzed.
Results: Fifty-seven patients with median follow-up of 44.8 months (range 24–73) were included. KOOS, SF-36 and VAS improved from a mean 58.5, 53.9 and 8.5 points to a mean 87.4, 86.6 and 1.2 at last follow-up (p b 0.001). Larger lesions showed less improvement in KOOS (p = 0.04) and SF-36 (p = 0.029). Median Tegner values were restored to preinjury situation (5, range 2–10). Mean MOCART score was 43.2 ± 16.1. Although the cartilage layer had good integration, it showed high heterogeneity and no filling of the subchondral bone layer.
Conclusions: TruFit failed to restore the normal MRI aspect of the subchondral bone and lamina in most cases. The appearance of the chondral layer in MRI was partially re-established. This unfavourable MRI appearance did not adversely influence the patient's outcome in the short time and they restored their previous level of activity. There was an inverse linear relationship between the size of the lesion and the functional scores.
Level of evidence: Therapeutic case series; level 4.
The Knee, April 2014
Clinical results after ultrasound-guided intratissue percutaneous electrolysis (EPI) and eccentric exercise in the treatment of patellar tendinopathy Abstract Descargar PDF Abstract
Purpose To investigate the outcome of ultrasound (US)- guided intratissue percutaneous electrolysis (EPIÒ) and eccentric exercise in the treatment of patellar tendinopathy during a long-term follow-up.
Methods Forty patients with patellar tendinopathy were prospectively evaluated over a 10-year follow-up period. Pain and function were evaluated before treatment, at 3 months and at 2, 5 and 10 years using the Victorian Institute of Sport Assessment–Patella (VISA-P) score, the Tegner score and Blazina’s classification. According to VISA-P score at baseline, patients were also dichotomized into Group 1 (\50 points) and Group 2 (C50 points). There were 21 patients in Group 1 and 19 in Group 2. Patient satisfaction was measured according to the Roles and Maudsley score.
Results The VISA-P score improved globally by 41.2 points (p \ 0.01) after a mean 4.1 procedures. In Group 1, VISA-P score improved from 33.1 ± 13 to 78.9 ± 14.4 at 3-month and to 88.8 ± 10.1 at 10-year follow-up (p \ 0.001). In Group 2, VISA-P score improved from 69.3±10.5to84.9±9at3-monthandto96.0±4.3at 10-year follow-up (p \ 0.001). After 10 years, 91.2 % of the patients had a VISA-P score[80 points. The same level (80 % of patients) or the Tegner score at no more than one level lower (20 % of patients) was restored, and 97.5 % of the patients were satisfied with the procedure.
Conclusion Treatment with the US-guided EPIÒ tech- nique and eccentric exercises in patellar tendinopathy resulted in a great improvement in knee function and a rapid return to the previous level of activity after few sessions. The procedure has proved to be safe with no recurrences on a long-term basis.
Level of evidence Therapeutic study, Level IV.
Knee Surg Sports Traumatol Arthrosc
Mecanismos moleculares de reparación mediante la técnica Electrólisis Percutánea Intratisular en la tendinosis rotuliana Abstract Descargar PDF Abstract
Objetivo: Investigar los mecanismos moleculares de respuesta tisular tras el tratamiento con la técnica Electrólisis Percutánea Intratisular (EPI®) en la tendinosis inducida por colagenasa tipo i en ratas Sprague Dawley.
Métodos: En una muestra de 24 ratas Sprague Dawley de 7 meses de edad y 300 g se indujo ten- dinosis mediante la inyección en el tendón rotuliano de 50 g de colagenasa tipo i. Se procedió a dividir la muestra en 4 grupos: un grupo control, un grupo colagenasa y 2 grupos de tratamiento con técnica EPI® a 3 y 6 mA, respectivamente. Se aplicó una sesión de tratamiento EPI® y tras 3 días se procedió al análisis de los tendones mediante técnicas de inmunodetección y electro- foresis. Se analizaron las proteínas citocromo C, Smac/Diablo, factor de crecimiento endotelial vascular y su receptor 2. También se analizó el factor de transcripción nuclear peroxisoma proliferador activado del receptor gamma.
Resultados: Se observó un aumento estadísticamente significativo en la expresión del citocromo C, Smac/Diablo, factor de crecimiento endotelial vascular, su receptor 2 y peroxisoma prolife- rador activado del receptor gamma en los grupos a los que se les aplicó la técnica EPI® respecto al grupo control.
Conclusiones: La técnica EPI® produce, en la lesión tendinosa inducida con colagenasa tipo i en ratas, un aumento de los mecanismos moleculares antiinflamatorios y angiogénicos.
Revista Española de Cirugía Ortopédica y Traumatología, 2014
Effectiveness of the Intratissue Percutaneous Electrolysis (EPI®) technique and isoinertial eccentric exercise in the treatment of patellar tendinopathy at two years follow-up Abstract Descargar PDF Abstract
Objectives: to show the effect of Intratissue Per- cutaneous Electrolysis (EPI®) combined with ec- centric programme in the treatment of patellar tendinopathy.
Methods: prospective study of 33 athlete-patients consecutively treated for insertional tendinopathy with Intratissue Percutaneous Electrolysis (EPI®) and followed for 2 years. Functional assessment was performed at the first visit, at three months and two years with the Tegner scale and VISA-P. Results: an average improvement in the VISA-P of 35 points was obtained. The mean duration of treatment was 4.5 weeks. Some 78.8% of the pa- tients returned to the same level of physical activ- ity as before the injury by the end of treatment, reaching 100% at two years.
Conclusion: intratissue percutaneous electroly- sis (EPI®) combined with an eccentric-based re- hab program offers excellent results in terms of the clinical and functional improvement of the patellar tendon with low morbidity in a short-term period.
Level of Evidence: Therapy, level 4.
Muscles, Ligaments and Tendons Journal 2014; 4 (2): 188-193
How to Improve the Prediction of Quadrupled Semitendinosus and Gracilis Autograft Sizes With Magnetic Resonance Imaging and Ultrasonography Abstract Descargar PDF Abstract
Background: Hamstring tendon grafts may have an unacceptable size for use in anterior cruciate ligament (ACL) reconstruction. Magnetic resonance imaging (MRI) has been proposed to predict the diameters of hamstring tendon grafts.
Hypothesis: Preoperative ultrasonography (US) might reliably anticipate intraoperative 4-strand semitendinosus and gracilis ten- don (4ST-GT) graft sizes similarly to MRI. An MRI evaluation of the hamstring tendons with a higher magnification may improve the accuracy of the method.
Study Design: Cohort study (diagnosis); Level of evidence, 2.
Methods: A total of 33 patients undergoing ACL reconstruction with a 4ST-GT graft and MRI performed at our institution were included. The cross-sectional area (CSA) of each semitendinosus tendon (ST) and gracilis tendon (GT) was calculated preoper- atively with US and with MRI under 23 and 43 magnification. Intraoperative measurement of the final diameter of the 4ST-GT using a closed-hole sizing block with 0.5-mm increments was made. Pearson correlation coefficients were calculated to deter- mine the relationship between the final intraoperative graft diameter of the 4ST-GT and the CSA of the ST and GT measured with US and MRI with 23 and 43 magnification. Simple linear regression was also calculated to attempt to predict the graft diameter based on given measurements.
Results: There were statistically significant correlations between the measured CSA with US and both MRI magnifications with the 4ST-GT diameter. However, MRI under 43 magnification showed a much higer correlation (0.86) than MRI under 23 magni- fication (0.54) or US (0.51). Final graft diameters 8 mm were observed in 80.8% of patients with a CSA .14 mm2, in 76.9% of patients with a CSA .25 mm2, and in 96.2% of patients with a CSA .17 mm2 measured with US, 23 magnification of MRI, and 43 magnification of MRI, respectively.
Conclusion: Preoperative calculation of the CSA of the hamstring tendons with MRI and US can help to reliably estimate 4ST-GT grafts. In terms of correlation of the CSA with graft diameter, US was comparable to 23 MRI, but 43 MRI showed a much greater accuracy. Threshold values of the CSA of the ST and GT of 25 mm2, 17 mm2, and 14 mm2 with the 23 MRI, 43 MRI, and US methods, respectively, are needed to reliably predict a 4ST-GT graft with a minimum diameter of 8 mm.
The American Journal of Sports Medicine, Vol. 41, No. 8, 2014
Fractura de escafoides carpiano en el niño. A propósito de un caso y revisión de la bibliografía Abstract Descargar PDF Abstract
RESUMEN. Objetivo: Realizar una revisión bi- bliográ ca de las infrecuentes fracturas del esca- foides carpiano en pacientes pediátricos a partir de un caso clínico. El diagnóstico es usualmente difícil y el tratamiento se considera que debería ser es- tricto para minimizar la posibilidad de un retraso de consolidación o seudoartrosis. Material y mé- todos: Niño de 10 años con fractura de escafoides carpiano visible en las radiografías simples. El pa- ciente no cumplió las instrucciones de tratamiento, retirando el yeso a las tres semanas pero con evo- lución no obstante a la consolidación sin secuelas clínicas. Discusión: Este caso es especialmente in- frecuente dado el excelente resultado obtenido con un período de inmovilización considerablemente más corto que el mínimo recomendado.
Acta Ortopédica Mexicana 2013; 27(5): Sep.-Oct: 335-338
Femoral Tunnel Drilling Angles for the Posterolateral Corner in Multiligamentary Knee Reconstructions: Computed Tomography Evaluation in a Cadaveric Model Abstract Descargar PDF Abstract
Purpose: The goal of this study was to determine the best angle at which to drill the femoral tunnels of the popliteus tendon (PT) and fibular collateral ligament (FCL) in combined reconstructive procedures so as to avoid either short tunnels or tunnel collisions with the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) femoral tunnels. Methods: Eight cadaveric knees were studied. ACL/PCL femoral tunnels were arthroscopically drilled. PT and FCL tunnels were drilled at 0 and 30 axial and coronal angulations. They were scanned by computed tomography to document relations of the PT and FCL tunnels to the intercondylar notch and ACL/PCL tunnels. A minimum tunnel length of 25 mm was required. Results: Drilling the PT tunnel at 0 axial angulation was associated with an increased risk of tunnel collision with the ACL (P < .001). Interference with the PCL tunnel can be avoided only if the K-wire guiding the PT tunnel is drilled with 30 coronal angulations (P < .001). The minimum tunnel length of the PT could be obtained only with both axial and coronal angulations of 30 (P 1⁄4 .003). Sufficient tunnel lengths of the FCL were obtained at all angulations evaluated (P 1⁄4 .036). However, only the tunnels drilled at 30 axial and 0 coronal angu- lations did not collapse with the ACL tunnels (P < .001). No intersections between FCL and PT tunnels were observed. Conclusions: When posterolateral reconstructions are performed in combination with concomitant anterior and posterior cruciate procedures, PT tunnels should be drilled at 30 axial and 30 coronal angulations. FCL tunnels should be drilled at 30 axial and 0 coronal angulations. These angulations should minimize such potential complications as short tunnels or collisions with the ACL/PCL tunnels. Clinical Relevance: Specific drilling angles are necessary to avoid short tunnels or collisions between the drilled tunnels when FCL and PT femoral tunnels are performed in multiligament knee reconstructions.
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 29, No 2 (February), 2013: pp 257-265
Promising short-term results following selective bundle reconstruction in partial anterior cruciate ligament tears Abstract Descargar PDF Abstract
Background: The different functions of the two anterior cruciate ligament (ACL) bundles have increased inter- est in tears of only one of these two bundles. The purpose of this study was to assess the outcome of selective reconstruction of an injured bundle of isolated anteromedial bundle (AMB) or posterolateral bundle (PLB) tears.
Methods: Consecutive series of 147 ACL reconstructions was prospectively analyzed. Patients with partial ACL tears who underwent selective bundle reconstructions were studied. Stability was assessed with the Lachman, anterior-drawer and pivot-shift tests and KT-1000. Functional assessment was performed with Lysholm and Tegner questionnaires. The preoperative MRI was analyzed to detect differences from arthro- scopic findings.
Results: Twenty-eight patients (19%) were included. The minimum follow-up period was 30 months. Eigh- teen had AMB and 10 PLB tears. Only 19% of their MRI's were categorized as partial ACL tears.
The Lysholm score improved from 66.1/65.5 to 96.6/95.2 in the AMB/PLB groups, respectively (p b 0.001). The same or no more than one level lower Tegner score was restored. The pivot-shift, Lachman and anterior-drawer tests were negative in all cases (p b 0.001). Two reconstructed AMBs developed extension loss due to Cyclops lesions and were resolved surgically.
Conclusions: The technique provided excellent functional scores with normalized stability and a return to previous level of activity with a low rate of minor complications at a minimum 2.5 years' follow-up. Arthro- scopic examination was the most reliable tool for properly diagnosing and treating a condition observed in almost one out of every five ACL reconstructed knee in this series.
The Knee, 2013, p. 232 -238
Prospective comparative study between two different fixation techniques in meniscal allograft transplantation Abstract Descargar PDF Abstract
Purpose To compare the functional and radiographic results between two different horn fixation techniques for meniscal allograft transplant.
Methods This is a prospective study of 88 meniscal allograft transplants with a mean 5-year follow-up. Forty transplants were performed on the medial compartment and 48 on the lateral compartment. The same surgeon per- formed all surgeries. Thirty-three grafts were fixed only with sutures (Group A) and 55 only with bony fixation (Group B). Both groups were comparable in terms of age, laterality, time since meniscectomy and preoperative functional and radiographic status. Functional assessment was done with Lysholm and Tegner scores and the Visual Analogical Scale for pain. Joint space narrowing was evaluated in the Rosenberg view.
Results There was a significant improvement in Lysholm, Tegner and VAS scores without differences between Group A and Group B (n.s.). Radiographic evaluation did not show any joint space narrowing (n.s.). No differences in the comparison of all the variables of the two compartments were found. There were complications in 33.3 % of patients in Group A that including 7 graft tears (21.4 %) and in which there was an allograft failure rate of 9 %. Group B showed complications in 16.4 % of the patients and included 4 graft tears (7.3 %, n.s.) with an allograft failure rate of 3.6 %.
Conclusions Meniscal allograft transplantation with either technique provided good functional and radiographic results at mid-term follow-up. Both graft fixation methods showed no differences relative to functional and radio- graphic results. There was a considerably higher rate of complications in transplantations performed with the only- suture technique than those with bony fixation, although the difference was not statistically significant with the numbers available. The results suggest that similar func- tional results should be expected whether the meniscal graft includes bone plugs or not. However, graft tears seem to happen more frequently if the MAT is performed without bony fixation.
Knee Surg Sports Traumatol Arthrosc (2013) 21:1516–1522
Myxoid Tumor Associated to Migration of a Suspensory Fixation Device of a Reconstructed Anterior Cruciate Ligament: A Case Report Abstract Descargar PDF Abstract
A 16-year-old male who had undergone 6 months before an anterior cruciate ligament (ACL) reconstruction with an autologous hamstring graft fixed with a suspensory fixation device (XoButton device; ConMed Linvatec, Largo, FL), complained of a slightly painful mass in the distal posterolateral aspect of the thigh. The knee was otherwise stable. A 79 60 17 mm multilobulated tumor surrounding the implant device was observed in magnetic resonance images. The revision arthroscopy showed an intact ACL graft. The tumor was excised through a longitudinal posterolateral approach. It had a myxoid appearance. The undamaged implant was also removed. Two months after surgery, the patient was already asymptomatic. Although most fixation device problems occur in the perioperative period due to an inadequate technique which may lead to graft instability, this case reminds clinicians of the possibility of later developing clinically relevant complications with suspensory fixation devices.
J Knee Surg 2013; 26 (Suppl 1):S50–S52.
Implant sonication increases the diagnostic accuracy of infection in patients with delayed, but not early, orthopaedic implant failure Abstract Descargar PDF Abstract
The purpose of this study was to compare the diagnostic accuracy for the detection of infection between the culture of fluid obtained by sonication (SFC) and the culture of peri- implant tissues (PITC) in patients with early and delayed implant failure, and those with unsuspected and suspected septic failure. It was hypothesised that SFC increases the diagnostic accuracy for infection in delayed, but not early, implant failure, and in unsuspected septic failure. The diagnostic accuracy for infection of all consecutive implants (hardware or prostheses) that were removed for failure was compared between SFC and PITC. This prospective study included 317 patients with a mean age of 62.7 years (9 to 97). The sensitivity for detection of infection using SFC was higher than using PITC in an overall comparison (89.9% versus 67%, respectively; p < 0.001), in unsuspected septic failure (100% versus 48.5%, respectively; p < 0.001), and in delayed implant failure (88% versus 58%, respectively; p < 0.001). PITC sensitivity dropped significantly in unsuspected compared with suspected septic failure (p = 0.007), and in delayed compared with early failure (p = 0.013). There were no differences in specificity. Sonication is mainly recommended when there is implant failure with no clear signs of infection and in patients with delayed implant failure. In early failure, SFC is not superior to PITC for the diagnosis of infection and, therefore, is not recommended as a routine diagnostic test in these patients.
The Bone & Joint Journal, July 2012
Lesiones ligamentosas de la rodilla Abstract Descargar PDF Abstract
Las lesiones de los ligamentos de la rodilla, y en concreto las del ligamento cruzado anterior, son algunas de las más habitua- les en traumatología deportiva. En la última década se han produ- cido avances en la reconstrucción de los diferentes ligamentos de la rodilla, en el conocimiento de la biología y de la biomecánica de la incorporación de los injertos, en nuevos materiales y dispositivos para su jación, y en nuevas pautas de rehabilitación. A pesar de ello, todavía no hay consenso sobre cómo prevenir estas lesiones, cuál es la mejor técnica para tratar o reconstruir los ligamentos, qué injerto es mejor, el dispositivo de jación más able, cómo estimular la biología, qué pauta de rehabilitación es más efectiva y adecuada, o de qué modo analizar de forma objetiva los resul- tados. Además, es difícil comparar los resultados obtenidos en los estudios debido al gran número de variables que pueden in uir en ellos, y que son tremendamente difíciles de homogeneizar.
José A. Hernández Hermoso Juan C. Monllau García
En este libro se revisa el estado actual del conocimiento, haciendo hincapié en los temas más controvertidos sobre los cuales no hay consenso, ante los que cada autor establece su opción.
Marge Medica Books, 2012
Host serum is not indispensable in collagen performance in viable meniscal transplantation at 4-week incubation Abstract Descargar PDF Abstract
Purpose Viable meniscal transplantation has been criti- cized as an expensive and logistically demanding tech- nique. The purpose was to compare the standard culture medium with another culture medium that is more widely available and easier to work with and to assess the collagen net ultrastructure architecture and the capacity of the pre- served cells to produce proteins.
Methods Ten fresh lateral menisci were harvested. Each meniscus was divided into three parts; control group, fetal- bovinum-serum group and Insulin-Transferrin-Selenium group during 4 weeks. Cell metabolism was assessed with the gene expression of type I collagen, type II collagen and aggrecan. Collagen ultrastructure was assessed with trans- mission electron microscopy. The Collagen Meniscal Architecture scoring system was used to evaluate the degree of meniscal disarray.
Results Type I collagen was expressed more in the fetal- bovinum-serum group than in the ITS group (P = 0.036). No differences were found between cultured samples and control groups. Type II collagen showed decreased expression in both cultured groups compared with the control group. No differences were observed in the gene expression of aggrecan in either group. No differences were observed when the Collagen Meniscal Architecture scoring system was applied.
Conclusions Insulin-Transferrin-Selenium-supplemented medium is at least as effective as the fetal-bovinum-serum- supplemented medium to preserve the net architecture of the meniscal tissue. Gene expression of the studied proteins was similar in the Insulin-Transferrin-Selenium group to that observed in the control group at 4 weeks. Insulin- Transferrin-Selenium might be a better alternative and might be used instead of fetal-bovinum-serum or an autologous host serum in order to preserve meniscal tissue, which precludes the necessity of obtaining host serum previously. Thus, viable meniscal transplantation would logistically be less complicated to perform.
Knee Surg Sports Traumatol Arthrosc (2012) 20:1681–1688
Extension Malunion of the Femoral Component After Retrograde Nailing: No Sequelae at 6 Years Abstract Descargar PDF Abstract
Objectives: Supracondylar femoral fracture is a complex compli- cation after total knee arthroplasty (TKA). One potential complica- tion of retrograde locked nailing is malunion in extension of the femoral prosthetic component—produced by an overly posterior nail entry point in the intercondylar notch. The aim of this study was to determine the repercussion of this deformity on the midterm radio- logical and functional outcomes of TKA.
Design: Retrospective review.
Methods: From 2001 to 2006, 30 patients were treated for supracondylar femoral fracture above TKA with a retrograde locked nail. In 7 patients (6 women and 1 man) with a mean age of 78.8 years (range, 74–84 years), more than 10 degrees of hyperex- tension (mean of 18.5 degrees) of the femoral component on the sagittal plane was observed without any significant misalignment on the coronal plane. Functional outcomes were assessed using the Knee Society Score.
Results: After a mean follow-up of 68.5 months (range, 48–111 months), all patients’ fractures with a hyperextension of the femoral component had consolidated with no clinical or radiological signs of TKA loosening. These patients presented “good” functional out- comes at final follow-up.
Conclusions: These results should be interpreted with caution. However, isolated hyperextension of the femoral component of a TKA after placing a retrograde nail for a periprosthetic fracture does not seem to significantly affect the functional or radiological outcomes at ;6-years follow-up.
J Orthop Trauma Volume 0, Number 0, Month 2012
Suture-Only Fixation Technique Leads to a Higher Degree of Extrusion Than Bony Fixation in Meniscal Allograft Transplantation Abstract Descargar PDF Abstract
Background: Most of the published series of transplanted menisci have consistently shown some degree of allograft extrusion. The speculation is that this meniscal extrusion may be caused by the soft tissue technique used to fix the allograft.
Hypothesis: The percentage of extruded meniscal graft would be higher if the allograft were only fixed with sutures rather than with associated bony fixation.
Study Design: Cohort study; Level of evidence, 2.
Methods: We performed a prospective series of 88 meniscal allograft transplantations. Thirty-three of the grafts were fixed with the suture-only technique (group A). The remaining 55 cases were performed with the bone plug method (group B). All patients were studied with magnetic resonance imaging (MRI) at a minimum 3 years’ follow-up to determine the degree of meniscal extru- sion. The time between surgery and MRI evaluation was 40 months (range, 36-48 months) in both groups. Meniscal extrusion was measured on coronal MRI. The percentage of the meniscal body width that was extruded was calculated. The average percent- age of extrusion for each group was compared. The Lysholm score was analyzed in relation to the fixation method and degree of meniscal extrusion. Tears of the allograft that required surgical intervention were also reported.
Results: The average percentage of meniscal tissue extruded in group A was 36.3% 6 13.7% without differences between the medial (35.9% 6 18.1%) and lateral (38.3% 6 14.4%) compartments (P = .84). Group B had a mean 28.13% 6 12.2% of the meniscal body extruded without differences between the medial (25.8% 6 16.2%) and lateral (30.14% 6 13.5%) compartments. A higher percentage of extruded meniscal tissue was found in group A than in group B (P \ .001). No association between the degree of meniscal extrusion and the functional score was observed (P = .4). Graft tears were observed in 21.4% of the cases in group A and in 7.3% of the cases in group B (P = .09).
Conclusion: A meniscal allograft fixed with the suture-only technique showed a significantly higher degree of extruded meniscal body than that fixed with the bony fixation method, with no influence on the functional outcome. There was also a considerably higher rate of graft tears observed in those menisci fixed only with sutures, although this difference was not statistically significant with the numbers available.
1592 Abat et al The American Journal of Sports Medicine, 2012, Vol. 40, No. 7
There is no relation between mild malalignment and meniscal extrusion in trauma emergency patients Abstract Descargar PDF Abstract
Objective: To evaluate whether an alteration of the lower limb axis is associated with meniscal extrusion. Materials and Methods: Ninety-four patients who had complained of knee pain with good knee function and had a knee magnetic resonance image (MRI) and a full-length X-ray taken of the lower limb were included in the study. Meniscal extrusion was measured in the coronal MRI. Subluxation of the meniscus was considered minor or physiological if 3 mm, and major if >3 mm. The extrusion as a percentage of meniscus size was also calculated. Knee alignment (varus, negative value; valgus, positive value) was correlated with the presence of minor and major extrusion.
Results: There were varus knees in 61 cases (58.7%), with a mean measured deviation of −2.63°. Valgus knees were observed in 27 knees (26%) and had a mean deviation of 2.22°. The medial meniscus showed major extrusion in 18 cases (17.3%). It corresponded to 44.7% of the meniscus size. The lateral menisci showed no subluxation in most cases. There was no correlation between alignment and meniscal extrusion in this series, either for the medial meniscus (p = 0.760) or for the lateral meniscus (p = 0.381).
Conclusions: In patients complaining of knee pain with good knee function, there is no relationship between mild malalignment and the degree of meniscus extrusion.
El Sevier, 2012
Fractura del cóndilo occipital. Reporte clínico y revisión de la literatura Abstract Descargar PDF Abstract
Objetivo: Llamar la atención sobre la existencia de la fractura del cóndilo occipital y la facilidad con la que pasan desapercibidas durante la atención del paciente politraumatizado. Es una lesión poco frecuente, especialmente en pacientes adolescentes, y debe tenerse en cuenta ante un traumatismo craneal con dolor cervical por sus potenciales consecuencias si estas fracturas no se tratan correctamente. La exploración radiográfica puede parecer normal, debiendo hacer el diagnóstico mediante tomografía computarizada. El tratamiento de elección depende de la estabilidad de la fractura.
Material y método: Dos pacientes varones de 17 y 40 an ̃os involucrados en sendos accidentes de motocicleta, presentaron una fractura impactada del cóndilo occipital. En ambos casos se realizó tratamiento conservador con collar cervical rígido.
Resultados: Se obtuvieron buenos resultados funcionales sin secuelas neurológicas. Conclusión y relevancia clínica: El conocimiento y sospecha de esta infrecuente entidad y su correcto diagnóstico y tratamiento es crucial para conseguir un buen resultado funcional, para así evitar potenciales lesiones neurológicas asociadas.
Revista Española de Cirugía Ortopédica y Traumatología, noviembre 2011
Effectiveness of a Footprint Guide to Establish an Anatomic Femoral Tunnel in Anterior Cruciate Ligament Reconstruction: Computed Tomography Evaluation in a Cadaveric Model Abstract Descargar PDF Abstract
Purpose: To compare drilling the femoral tunnel with an offset aimer and BullsEye guide (ConMed Linvatec, Largo, FL) to perform an anatomic single-bundle reconstruction of the anterior cruciate ligament (ACL) through the anteromedial portal. Methods: Seven matched pairs of cadaveric knees were studied. The intent was to drill the femoral tunnel anatomically in all cases. In group A the femoral tunnel was drilled arthroscopically with an offset aimer. In group B the femoral tunnel was drilled arthroscopically with the BullsEye guide. Two tunnels were drilled through the same entry point in each knee. One was done at 110° of knee flexion and the other at 130°. They were scanned by computed tomography and reconstructed 3-dimensionally. Volume-rendering software was used to document relations of the drilled tunnel to the bony anatomy and tunnel length. Results: In group B the femoral tunnel was placed at the center of the femoral insertion site. The center of the tunnel was 9.4 mm from the high cartilage margin and 8.6 mm from the low cartilage margin. In group A the tunnels were placed deeper (5.4 mm and 12.6 mm, respectively) (P .018). There were no differences in tunnel length for either knee flexion degree. Three of the tunnels drilled at 110° in group A compromised the posterior tunnel wall and measured less than 25 mm in length. Conclu- sions: Accurate placement in the center of the femoral footprint of the ACL is better accomplished with the BullsEye guide rather than 5-mm offset aimers. Five-millimeter offset aimers might cause posterior tunnel blowout and present the risk of obtaining short tunnels when performing oblique femoral tunnel placement through the anteromedial portal at 110° of knee flexion. Clinical Rele- vance: The BullsEye guide might be better than standard offset aimers in the performance of anatomic single-bundle ACL reconstruction.
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 27, No 6 (June), 2011: pp 817-824 817
Outcome After Partial Medial Meniscus Substitution With the Collagen Meniscal Implant at a Minimum of 10 Years’ Follow-up Abstract Descargar PDF Abstract
Purpose: The aim of the study was to evaluate the clinical outcome of a collagen meniscus graft implanted in an injured medial meniscus after a minimum of 10 years’ follow-up. Methods: Twenty-five patients underwent arthroscopic implantation of the collagen meniscus device. They had either persistent compartmental joint line pain due to a previous medial meniscus resection (5 cases) or a large irreparable meniscus tear at arthroscopy (20 cases). Implant failure was defined as infection due to the implant or mechanical failure of the device. Twenty-two patients returned for clinical, functional, and radiographic evaluation. Magnetic resonance imaging was also performed and was analyzed with the criteria of Genovese et al. (where type 3 indicates normal and type 1 indicates completely abnormal). All the aforementioned evaluations were carried out at a minimum of 10 years (range, 10.1 to 12.5 years) after the procedure. Results: The mean Lysholm score improved from 59.9 preoperatively to 89.6 at 1 year (P .001), and it was 87.5 at final follow-up (P .001). The results were good or excellent in 83% of the population. No differences were observed when we compared the Lysholm score at 1 year of follow-up with the score at final follow-up (P .05). The mean pain score on a visual analog scale improved by 3.5 points at final follow-up. Patient satisfaction with the procedure was 3.4 of 4 points. Radiographic evaluation showed either minimal or no narrowing of the joint line. Magnetic resonance imaging showed type 2 in 64% of cases and type 3 in 21%. All cases showed less volume than expected (size type 2 in 89%). The failure rate in the patient population was 8% (2 of 25). There were no complications related to the device. Conclusions: Although there were several different types of patients and acute and chronic tears were treated in a limited number of patients, meniscal substitution with the collagen meniscal implant provides significant pain relief and functional improvement after a minimum of 10 years’ follow-up. The implant generally diminished in size, but the procedure proved to be safe and had a low rate of implant failure on a long-term basis. No development or progression of degenerative knee joint disease was observed in most cases. Level of Evidence: Level IV, therapeutic case series.
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 27, No 7 (July), 2011: pp 933-943
Fractura aislada del cuerpo del hueso ganchoso. A propósito de un caso Abstract Descargar PDF Abstract
Objetivo: Mostrar mediante un caso clínico que las fracturas del hueso ganchoso son muy poco frecuentes, mucho menos aún las que afectan al cuerpo del mismo sin fracturas asociadas de otros huesos del carpo. Debido a su infrecuencia y a la inespecificidad de sus manifestaciones clínicas, suelen ser de difícil diagnóstico.
Material y método: Presentamos el caso de un varón de 24 an ̃os, que sufrió fractura conminuta aislada del cuerpo del hueso ganchoso. Fue tratado de forma conservadora, obteniéndose una recuperación ad integrum sin déficit funcional.
Conclusiones: Es importante considerar este tipo de fracturas ante un traumatismo directo sobre la mano. Es recomendable la realización de una tomografia computerizada (TC) para caracterizar correctamente la fractura y valorar las posibles lesiones asociadas. La decisión terapéutica depende del grado de conminución de la fractura, de su estabilidad y de la afec- tación articular.
Revista Española de Cirugía Ortopédica y Traumatología, abril de 2011
Allogenic labral transplantation in hip instability following arthroscopic labrectomy Abstract Descargar PDF Abstract
The acetabular labrum augments femoral head coverage within the acetabulum and contrib- utes to hip joint stability. This has led to an increasing interest in procedures dedicated to preservation of the labrum. An allogenic labral transplantation performed in a patient who had previously under- gone a partial labral resection is presented.
Allogenic labral transplantation in hip instability following arthroscopic labrectomy Abstract Descargar PDF Abstract
The acetabular labrum augments femoral head coverage within the acetabulum and contrib- utes to hip joint stability. This has led to an increasing interest in procedures dedicated to preservation of the labrum. An allogenic labral transplantation performed in a patient who had previously under- gone a partial labral resection is presented.
Hip Int 2011;02 ( 02 ): 000 - 000
Meniscal Allograft Transplantation Without Bone Blocks: A 5- to 8-Year Follow-Up of 33 Patients. Abstract Descargar PDF Abstract
Purpose: The purpose of this study was to evaluate the functional and radiographic results on a midterm basis, as well as complications, in an initial series of meniscal allograft transplantations performed with suture fixation without any bone block. Methods: A series of 33 meniscal allograft transplantations were performed at our institution from January 2001 to October 2003. Inclusion criteria were patients with compartmental joint line pain due to a previous meniscec- tomy. There were 24 men and 9 women with a mean age of 38.8 years (range, 21 to 54 years). The functional outcomes were evaluated by use of Lysholm and Tegner scores at a mean and minimum follow-up of 6.5 years and 5 years, respectively. A visual analog scale for pain was also used. Radiographic assessment included joint space narrowing on the Rosenberg view and magnetic resonance imaging evaluation. Results: The Lysholm and Tegner scores significantly improved from 65.4 to 88.6 (P .001) and from 3.1 to 5.5 (P .001), respectively, after surgery. The visual analog scale score significantly dropped from 6.4 to 1.5 (P .001). The radiographic evaluation did not show any joint space narrowing (P .38). Meniscal extrusion was a constant finding, averaging 36.3% of total meniscal size. According to the Van Arkel criteria, the survival rate was 87.8% at 6.5 years. The rate of complications was 33%. Conclusions: This study suggests that this procedure provides significant pain relief and functional improvement in selected symptomatic individuals on a midterm basis. However, there was a high rate of complications (33%) and revision surgery. Level of Evidence: Level IV, therapeutic case series.
Arthroscopy: The Journal of Arthroscopic and Related Surgery. December 2010. Volume 26, Issue 12, Pages 1633–1640.
Allograft Meniscus Transplantation: A Current Review Abstract Descargar PDF Abstract
Meniscal tissue’s ability to heal has been shown to be limited. Until recently, orthopedic surgeons treating patients who had undergone a meniscectomy had few options available to treat the persistent pain sometimes associated with it and the subsequent early joint degeneration. This was true except in cases of limb malalignment. Meniscal allograft transplantation was introduced in the eighties to deal with the matter at hand and tends to produce good mid-term results when used on patients who have undergone meniscectomy. This article explores the history, indications, technique, results, and current concerns relative to this procedure. The investigators’ perspective derived from having carried out more than 100 allograft meniscal transplantations over the past 9 years is also laid out.
Techniques in Knee Surgery Volume 9, Number 2, June 2010
- Good outcome after meniscal repair using an all-inside suturing system in combination with high-frequency biostimulation. Descargar PDF Orthopedics. 2010 Jun 1;33(6):407-12. doi: 10.3928/01477447-20100429-21. No abstract available. PMID: 20806749 [PubMed - in process]
Effect of femoral tunnel length on the safety of anterior cruciate ligament graft fixation using cross-pin technique: a cadaveric study. Abstract Descargar PDF Abstract
Background: A more oblique placement of the anterior cruciate ligament (ACL) graft has been related to better control of rotatory knee stability. Femoral fixation with a transverse system might injure its posterolateral structures. Hypothesis: A cross-pin system, originally developed for transtibial reconstruction of the ACL, can safely be used when creating a lower femoral tunnel through the anteromedial portal. However, a long femoral tunnel must be created to protect the postero- lateral structures of the knee. Study Design: Controlled laboratory study. Methods: An ACL was arthroscopically reconstructed with a hamstring graft in 22 fresh cadaveric knees. The femoral tunnel was anatomically drilled in all cases. Knee flexion angle was set at 110°. Femoral fixation was performed with a cross-pin system. A 30-mm-long femoral tunnel was created in 11 knees (group A). In the remaining 11 knees, the femoral tunnel was drilled as long as each lateral condyle permitted (group B). For both groups, the relationships were compared between the cross-pin and the lateral collateral ligament (LCL), popliteus tendon, articular cartilage, and peroneal nerve. Results: In 5 cases of group A, the cross-pin was placed either through the LCL or between the LCL and popliteus tendon, whereas in group B it was always posterior to the LCL (P 5 .035). The cross-pin was closer to the articular cartilage in group A than in group B (7.14 mm versus 16.9 mm; P \ .001). The minimal distance to the peroneal nerve in all specimens was 23.89 mm. Conclusion: Hamstring graft fixation with a cross-pin system from the anteromedial portal with a 30-mm femoral tunnel presents a higher risk of injury to the LCL. The femoral tunnel should be drilled as long as possible. Clinical Relevance: A long femoral tunnel is required for safe transverse femoral fixation in an anatomical ACL reconstruction.
Am J Sports Med. 2010 Sep;38(9):1877-84. Epub 2010 May 26.PMID: 20505057 [PubMed - in process]Related citations
Anatomic single-bundle anterior cruciate ligament reconstruction from the anteromedial portal: evaluation of transverse femoral fixation in a cadaveric model. Abstract Descargar PDF Abstract
Purpose: The purpose of this study was to assess the risk of injury to the posterolateral structures of the knee when performing anterior cruciate ligament reconstruction from the anteromedial portal while fixing the graft with a femoral cross-pin system. Methods: The anterior cruciate ligament was reconstructed arthroscopically with hamstring graft in 10 fresh cadaveric knees. Femoral fixation was performed with a cross-pin system. This was originally developed for a transtibial drilling technique. A femoral tunnel measuring 30 mm in length was drilled through the anteromedial portal in each knee. The knee flexion angle was set at 110°. Lateral dissection was then performed to measure the distances from the cross-pin system to the lateral collateral ligament, the popliteus tendon, the lateral gastrocnemius tendon, and the peroneal nerve. Results: The lateral collateral ligament was partially torn by the pin in 1 case. In 8 cases the distance to the lateral collateral ligament was shorter than 3 mm (range, 0 to 2.43 mm). In 7 specimens, the cross-pin system was within 4.5 mm of the popliteus tendon. The lateral gastrocnemius tendon was pierced by the cross-pin device in 2 cases. The minimal distance to the peroneal nerve was 23.89 mm. Conclusions: Fixation of a hamstring graft with a cross-pin system initially developed for an upper femoral tunnel, following the aforementioned technique, presents the possibility of a high risk of injury to the lateral collateral ligament. The popliteus tendon and the lateral gastrocnemius tendon may also be injured. Clinical Relevance: The risk of injury to the lateral stabilizers of the knee suggests discarding the technique used in this study.
Arthroscopy. 2010 May;26(5):651-7. Epub 2010 Mar 20.PMID: 20434663 [PubMed - indexed for MEDLINE]
Arthroscopically assisted knee contracture release secondary to melorheostosis: a case report Abstract Descargar PDF Abstract
Melorheostosis is a rare non-hereditary bone disease characterized by a radiographic pattern of flowing hyperostosis along the cortex with sclerotomal distribution. We report a case of a patient with severe knee contracture and a restricted range of motion caused by intraarticular bone fragment and hyperostotic bone lesions secondary to melorheostosis. An arthroscopically assisted approach was used successfully in order to remove free bone fragments and to release the hyperostotic lesions in the bone cortex of the distal femur.
Knee Surg Sports Traumatol Arthrosc, April 2010
The effects of previous meniscus and anterior cruciate ligament injuries in patients with total knee arthroplasty. Abstract Descargar PDF Abstract
Background. Patients undergoing total knee replacement constitute a suitable population for studying the natural history of traumatic joint injuries. Material and methods. We studied all patients who received a TKA (Total knee arthroplasty) over the course of one year, in five different centers. The study involved 474 patients who had undergone a primary TKA for knee OA over a one-year period. In each patient, we analyzed age, sex, side of operation, weight, height and body mass index (BMI, kg/m2). BMI results were stratified into four groups according to the WHO classifica- tion: normal (<25), overweight (>25 and <30), obese (>30 and <40), and morbidly obese (>40). Results. In the TKA group, 74% of the patients were women, while in the THA group the percentage of men and women was similar. No differences were found in the sides operated on. Differences between both groups were found in knee alignment. Women were operated on more frequently for TKA, as there was a higher inci- dence of OA of the knee joints in women aged over 65. Conclusions. Patients who required a total knee arthroplasty are likely to have previously undergone sur- gery or trauma to the knee joints.
Ortop Traumatol Rehabil. 2010 Jan-Feb;12(1):50-7.PMID: 20203345 [PubMed - in process]
Reduced proliferation and osteocalcin expression in osteoblasts of male idiopathic osteoporosis. Abstract Abstract
Osteoporosis is characterized by low bone mineral density (BMD), resulting in increasing susceptibility to bone fractures. In men, it has been related to some diseases and toxic habits, but in some instances the cause of the primary--or idiopathic--osteoporosis is not apparent. In a previous study, our group compared histomorphometric measurements in cortical and cancellous bones from male idiopathic osteoporosis (MIO) patients to those of control subjects and found reduced bone formation without major differences in bone resorption. To confirm these results, this study analyzed the etiology of this pathology, examining the osteoblast behavior in vitro. We compared two parameters of osteoblast activity in MIO patients and controls: osteoblastic proliferation and gene expression of COL1A1 and osteocalcin, in basal conditions and with vitamin D(3) added. All these experiments were performed from a first-passage osteoblastic culture, obtained from osteoblasts that had migrated from the transiliac explants to the plate. The results suggested that the MIO osteoblast has a slower proliferation rate and decreased expression of genes related to matrix formation, probably due to a lesser or slower response to some stimulus. We concluded that, contrary to female osteoporosis, in which loss of BMD is predominantly due to increased resorption, low BMD in MIO seems to be due to an osteoblastic defect.
Calcif Tissue Int. 2010 Mar;86(3):220-6. Epub 2010 Jan 26.PMID: 20101397 [PubMed - indexed for MEDLINE]
In vivo evaluation of 3-dimensional polycaprolactone scaffolds for cartilage repair in rabbits. Abstract Descargar PDF Abstract
BACKGROUND: Cartilage tissue engineering using synthetic scaffolds allows maintaining mechanical integrity and withstanding stress loads in the body, as well as providing a temporary substrate to which transplanted cells can adhere. PURPOSE: This study evaluates the use of polycaprolactone (PCL) scaffolds for the regeneration of articular cartilage in a rabbit model. STUDY DESIGN: Controlled laboratory study. METHODS: Five conditions were tested to attempt cartilage repair. To compare spontaneous healing (from subchondral plate bleeding) and healing due to tissue engineering, the experiment considered the use of osteochondral defects (to allow blood flow into the defect site) alone or filled with bare PCL scaffold and the use of PCL-chondrocytes constructs in chondral defects. For the latter condition, 1 series of PCL scaffolds was seeded in vitro with rabbit chondrocytes for 7 days and the cell/scaffold constructs were transplanted into rabbits' articular defects, avoiding compromising the subchondral bone. Cell pellets and bare scaffolds were implanted as controls in a chondral defect. RESULTS: After 3 months with PCL scaffolds or cells/PCL constructs, defects were filled with white cartilaginous tissue; integration into the surrounding native cartilage was much better than control (cell pellet). The engineered constructs showed histologically good integration to the subchondral bone and surrounding cartilage with accumulation of extracellular matrix including type II collagen and glycosaminoglycan. The elastic modulus measured in the zone of the defect with the PCL/cells constructs was very similar to that of native cartilage, while that of the pellet-repaired cartilage was much smaller than native cartilage. CONCLUSION: The results are quite promising with respect to the use of PCL scaffolds as aids for the regeneration of articular cartilage using tissue engineering techniques.
Am J Sports Med. 2010 Mar;38(3):509-19. Epub 2010 Jan 21.PMID: 20093424 [PubMed - indexed for MEDLINE]
Bifurcated popliteus tendon: a descriptive arthroscopic study. Abstract Abstract
The objective of this study was to confirm the presence and frequency of a bifurcation of the popliteus tendon. The popliteus tendon has received attention due to its important function as a knee stabiliser. Several anatomical variants have recently been reported, one of them being a bifurcated tendon. However, the actual frequency as well as the possible role of this particular variant is still unknown. We prospectively analysed a series of 1,569 arthroscopies between January 2005 to December 2007. Six asymptomatic bifurcated popliteus tendons were found. No alterations in the magnetic resonance imaging were seen and no clinical signs (related to the popliteus tendon) were observed in these patients before surgery. In all cases the morphological variant was found by chance. Our results suggest that the presence of a bifurcated popliteus tendon is a fact and that its frequency, not previously reported, should not be ignored.
Int Orthop. 2009 Dec;33(6):1633-5. Epub 2008 Nov 8.PMID: 18998130 [PubMed - indexed for MEDLINE]
Symptomatic ganglions in the knee joint. Report of three cases and literature review. Abstract Abstract
BACKGROUND: The cystic lesions seen around the knee are usually meniscal or popliteal cysts. Cysts inside the articular cavity of the knee are rare and they are usually detected as incidental MRI findings. The ganglions originating in the cruciate ligaments or the infrapatellar fat have rarely been reported. We are reporting the cases of three intraarticular ganglions. The clinical diagnosis was made with magnetic resonance imaging. All patients were treated With arthroscopic surgery using the synovial shaver to remove the tissue. The three patients were reported as asymptomatic during the follow-up, with full range of motion. CONCLUSIONS: The literature review shows that the origin of ganglions is controversial. The three reported cases show that this is a pathology that should be suspected, as it is difficult to diagnose. MRI is essential to make the diagnosis and the arthroscopic treatment of intraarticular ganglions is effective.
Acta Ortop Mex. 2009 Jul-Aug;23(4):223-7. Review. Spanish. PMID: 19960661 [PubMed - indexed for MEDLINE]
Cryopreservation does not alter the ultrastructure of the meniscus. Abstract Descargar PDF Abstract
Fresh frozen menisci have recently been shown to have an altered meniscal ultrastructure. The cause might be a deterioration of its permeability due to collagen net disarray. The purpose of this study was to evaluate the cryopreserved meniscus in terms of ultrastructure and cellularity. Ten fresh human lateral menisci were harvested. Collagen architecture was evaluated with transmission electron microscopy. The Collagen Meniscal Architecture scoring system was used to assess the degree of meniscal disarray. Cell population, was also evaluated. The fibril collagen diameters of those menisci which had been previously cryopreserved showed an average size in the longitudinal section of 12.6 +/- 1.3 nm, whereas it was 13.4 +/- 2.2 nm in the menisci used as controls (n.s.). In the transverse section, the cryopreserved menisci averaged 15.5 +/- 2.4 and 16.7 +/- 3.5 nm in the controls (n.s.). The study group scored 4.8 points +/- 1.7, whereas the control group did so at 4.1 +/- 1.3 (n.s.). The percentage of cell survival after the cryopreservation ranged from 4 to 54. The fibril diameters and degree of disarray showed a similar distribution in both groups. The results suggest that meniscal cryopreservation does not alter the meniscal ultrastructure. Therefore, an allograft stored in that way would not alter its biomechanical properties, although its cellular viability is highly unpredictable.
Knee Surg Sports Traumatol Arthrosc. 2009 Jun;17(6):639-44. Epub 2009 Feb 19.PMID: 19225756 [PubMed - indexed for MEDLINE]
Freezing causes changes in the meniscus collagen net: a new ultrastructural meniscus disarray scale. Abstract Descargar PDF Abstract
Alterations in meniscal permeability leading to nutritional deficit have been suggested as a cause of shrinkage in meniscal transplantation. The purpose of this study was to ascertain how freezing, one of the most common procedures used to preserve meniscal allografts, alters the collagen's architecture. Twenty-six fresh human external menisci were analyzed with transmission electron microscopy. Thirteen of them were previously frozen at -80 degrees C while the rest were used as controls. A new scale of the collagen meniscal architecture was proposed according to the collagen's periodicity and degree of disruption, loss of banding, degree of collagen packing, fibril size variability and its intrafibrilar oedema. Each meniscus was scored from 0 to 7. Subsequently they were classified in grades ranging from a normal state (grade I; 0-2 points) to severe disarray (grade III; 5-7 points). The fibril collagen diameters of those menisci which had been previously frozen showed an average size in the longitudinal section of 14.26 nm, whereas it was 17.28 nm in the menisci used as controls (p=0.019). In the transverse section, the frozen menisci averaged 13.14 and 16.93 nm in the controls (p=0.003). Samples of the 13 previously frozen menisci were classified as grade III in 61.54% of the cases. In the control group, all the menisci were classified either as grade I or II. The frozen menisci averaged 4.85 points, whereas the control group did so at 2.46 (p<0.001). The fibril diameters in frozen menisci showed a thinner diameter and had a higher degree of disarray. Therefore, the results suggest that the freezing process alters the menisci's collagen net. This could partially explain the pathological changes found in shrunken menisci after transplantation.
Knee Surg Sports Traumatol Arthrosc. 2008 Apr;16(4):353-9. Epub 2007 Dec 8.PMID: 18066525 [PubMed - indexed for MEDLINE]
- Symptomatic ring-shaped medial meniscus. Descargar PDF Clin Anat. 2007 Nov;20(8):994-5. No abstract available. PMID: 17948289 [PubMed - indexed for MEDLINE]
- Pain, swelling, and progressive weakness of the left knee over 6 years Enferm Infecc Microbiol Clin. 2008 Nov;26(9):595-6. Spanish. No abstract available. PMID: 19100182 [PubMed - indexed for MEDLINE]
A porous PCL scaffold promotes the human chondrocytes redifferentiation and hyaline-specific extracellular matrix protein synthesis. Abstract Descargar PDF Abstract
The redifferentiation, proliferation, and hyaline-specific extracellular matrix (ECM) protein synthesis of chondrocytes cultured in a polycaprolactone (PCL) scaffold were analyzed. Gene expression of the type II collagen and aggrecan was assessed by real-time PCR in cells from PCL scaffolds, monolayer, and pellet cultures. The proliferative activity was assessed using Ki-67 immunodetection, and the chondrocytic differentiation was evaluated using S-100 immunodetection. The synthesis and deposition into scaffold pores of type II collagen and glycosaminoglycan were analyzed by immunohistochemistry and Alcian blue staining, respectively. All parameters were assessed throughout 28 days of cultures maintained in either fetal bovine serum-containing medium (FCM) or Insulin-Transferrin-Selenium-containing medium (ICM). Expression of the type II collagen gene was lower in FCM cultures than in ICM cultures for all culture systems (p < 0.05). Moreover, PCL scaffolds cultured in ICM were able to induce collagen gene expression more efficiently than pellet and monolayer cultures. Aggrecan gene expression did not vary significantly between mediums and three-dimensional system cultures, but in ICM cultures, the monolayer cultures had significantly higher levels of aggrecan gene expression than did either the PCL or pellet cultures. Chondrocytes cultured in PCL scaffolds or pellets with FCM did not proliferate to a great extent but did maintain their differentiated phenotype for 28 days. Levels of cartilage ECM protein synthesis and deposition into the scaffold pores were similar among PCL and pellet cultures grown in FCM and in ICM. In conclusion, chondrocytes seeded into PCL scaffolds, cultured in ICM, efficiently maintained their differentiated phenotype and were able to synthesize cartilage-specific ECM proteins.
J Biomed Mater Res A. 2008 Jun 15;85(4):1082-9.PMID: 17937412 [PubMed - indexed for MEDLINE]
Biodegradable PCL scaffolds with an interconnected spherical pore network for tissue engineering. Abstract Descargar PDF Abstract
A technique for producing controlled interconnected porous structures for application as a tissue engineering scaffold is presented in this article. The technique is based on the fabrication of a template of interconnected poly(ethyl methacrylate) (PEMA) microspheres, the introduction of a biodegradable polymer, poly-epsilon-caprolactone (PCL), and the elimination of the template by a selective solvent. A series of PCL scaffolds with a porosity of 70% and pore sizes up to 200 microm were produced and characterized (both thermally and mechanically). Human chondrocytes were cultured in monolayer on bulk PCL disks or seeded into porous PCL scaffolds. Cell adhesion, viability, proliferation, and proteoglycan (PG) synthesis were tested and compared with monolayer cultures on tissue-treated polystyrene or pellet cultures as reference controls. Cells cultured on PCL disks showed an adhesion similar to that of the polystyrene control (which allowed high levels of proliferation). Stained scaffold sections showed round-shaped chondrocyte aggregates embedded into porous PCL. PG production was similar to that of the pellet cultures and higher than that obtained with monolayer postconfluence cultures. This shows that the cells are capable of attaching themselves to PCL. Furthermore, in porous PCL, cells maintain the same phenotype as the chondrocytes within the native cartilage. These results suggest that PCL scaffolds may be a suitable candidate for chondrocyte culture.
J Biomed Mater Res A. 2008 Apr;85(1):25-35.PMID: 17688257 [PubMed - indexed for MEDLINE]
Benefits of arthroscopic tuberculoplasty in posterior ankle impingement syndrome. Abstract Abstract
The purpose of this work was to describe the posterior ankle impingement syndrome related to the posterolateral tubercle of the talus bone and to present a retrospective analysis of our results after arthroscopic plasty of the tubercle in 15 ankles with a mean 3-year follow-up. Fifteen cases of posterior ankle impingement (PAI) underwent arthroscopic excision of an impinging bone spur. All the patients (13) were retrospectively evaluated at an average of 36 months after index surgery. There were seven women (bilateral in two of them) and six men. Ten were involved in different kinds of sport and three were professional ballet dancers. Preoperative symptoms included pain localized in the posterior ankle, limitation of motion, weakness and swelling. All patients had failed a course of conservative therapies. Surgery was performed through posterolateral and posteromedial portals as described by van Dijk. After soft tissue debridement, partial resection of the posterolateral process was performed until there was complete plantar flexion without bone impingement. Postoperatively, all patients followed the same rehabilitation protocol. Improvement in their impingement symptoms was recorded in all of them according to AOFAS score. One of them (7%) still had occasional discomfort. The results suggest that arthroscopic bone decompression of the posterolateral tubercle in cases of PAI resistant to non-surgical therapies is an effective treatment.
Knee Surg Sports Traumatol Arthrosc. 2007 Oct;15(10):1235-9. Epub 2007 Jun 23.PMID: 17589829 [PubMed - indexed for MEDLINE]
Simvastatin and atorvastatin enhance gene expression of collagen type 1 and osteocalcin in primary human osteoblasts and MG-63 cultures. Abstract Abstract
To clarify the mechanism of the stimulatory effect of statins on bone formation, we have assessed the effect of simvastatin and atorvastatin on osteoblast activity by analysing cell proliferation, as well as collagen, osteocalcin, and bone morphogenetic protein-2 (BMP2) gene expression in primary human osteoblast (hOB) and MG-63 cell line cultures. Explants of bone from patients without any metabolic disease under orthopedic hip procedures were used to obtain hOB. Cell cultures were established, synchronized, and different concentrations of simvastatin or atorvastatin were added (10(-9) M, 10(-8) M, 10(-7) M, 10(-6) M) during the experiment. Cell proliferation was analyzed after 24 h. Collagen polypeptide alpha1 type 1 (COL1A1) gene expression, osteocalcin, and BMP2 expression levels were quantified by real-time PCR after 24 h incubation with statins. There was a statistically significant decrease in cell proliferation related to simvastatin or atorvastatin addition at all concentrations in primary hOB compared with those not treated. A significant increase in COL1A1, osteocalcin, and BMP2 gene expression was detected when hOB cultures were treated with simvastatin or atorvastatin at different concentrations. Similar but less significant effects were found on MG-63 cells. After statin treatment we observed both an arrest of proliferation in hOB cells and an increase in collagen, osteocalcin, and BMP2 gene expression, consistent with a stimulatory effect towards mature osteoblast differentiation. These findings support the bone-forming effect of statins, probably through the BMP2 pathway.
J Cell Biochem. 2007 Aug 15;101(6):1430-8.PMID: 17252541 [PubMed - indexed for MEDLINE]
A comparison of risk between the lateral decubitus and the beach-chair position when establishing an anteroinferior shoulder portal: a cadaveric study. Abstract Descargar PDF Abstract
PURPOSE: The purpose of this study was to assess, using a technique that minimally distorts the normal anatomy, the risk of injury when establishing a 5 o'clock shoulder portal in the lateral decubitus versus beach-chair position. METHODS: The anteroinferior portal was simulated with Kirschner wires (K-w) drilled orthogonally at the 5 o'clock position in 13 fresh frozen human cadaveric shoulders. The neighboring neurovascular structures were identified through an anteroinferior window made in the inferior glenohumeral ligament. Their relations to the K-w and surrounding structures were recorded in both positions. RESULTS: The median distance from the musculocutaneous nerve to the K-w was shorter in the lateral decubitus position than in the beach chair position (13.16 mm v 20.49 mm, P = .011). The cephalic vein was closer to the portal in the beach-chair position than in the lateral decubitus position (median 8.48 mm v 9.93 mm, P = .039). The axillary nerve was closer to the K-w in the lateral decubitus position than in the beach-chair position (median 21.15 mm v 25.54 mm, P = .03). No differences in the distances from the K-w to the subscapular and anterior circumflex arteries were found when comparing both positions. The mean percentage of subscapular muscle height from its superior border to the K-w was 53.03%. CONCLUSIONS: This study showed the risk of injury establishing a transubscapular portal in either position. The musculocutaneous nerve and the cephalic vein are the most prone to injury. In general, the beach-chair position proved to be safer. CLINICAL RELEVANCE: Inserting anchor devices orthogonally would permit stronger fixation but presents the risk of damaging neurovascular structures. This study focused on showing the neurovascular risk of performing full orthogonal insertion. Considering the good results reported with the usual superior-anterior portals, we do not recommend performing a transubscapular portal in routine shoulder arthroscopy.
Arthroscopy. 2007 May;23(5):522-8.PMID: 17478284 [PubMed - indexed for MEDLINE]
- Fibrosarcoma at the site of a metallic fixation of the tibia--a case report and literature review. Descargar PDF Acta Orthop Scand. 2000 Jun;71(3):329-32. Review. No abstract available. PMID: 10919312 [PubMed - indexed for MEDLINE]
Innervation patterns of the inferior glenohumeral ligament: anatomical and biomechanical relevance. Abstract Descargar PDF Abstract
Although the Inferior Glenohumeral Ligament (IGHL) has a well known mechanical and proprioceptive relevance in shoulder stability, the interrelation of the ligament's anatomical disposition/innervation has not actually been described previously. The purpose of the study was to determine the IGHL innervation patterns and relate them to dislocation. Forty-five embalmed and 16 fresh-frozen human cadaveric shoulders were studied. Masson's Trichrome staining detailed the intraligamentous nerve fiber arrangements. The effect on the articular nerves of an anteroinferior dislocation of the shoulder joint and the position of 60 degrees abduction and 45 degrees external rotation was studied dynamically. The axillary nerve provided IGHL innervation in 95.08% of the cases. We saw two distinct innervation patterns originating from the axillary nerve. In Type 1, one or two collaterals diverged later from the main trunk to enter the ligament. Type 2 showed innervation to the ligament provided by the posterior branch for three to four neural branches. In both cases, these branches enter the ligament near the glenoid rim and at the 7 o'clock position (right shoulder). The radial nerve (Type 3 innervation pattern) provided IGHL innervation in 3.28% of the cases. Microscopic analysis revealed wavy intraligamentous neural branches. The articular branches relaxed and separated from the capsule at the apprehension position and stayed intact after dislocation. These results showed a special predisposition to avoid possible denervation and suggested that the neural arch probably remains unaffected after most dislocations. Knowledge of the neural anatomy of the shoulder will clearly help in avoiding its injury in surgical procedures.
Clin Anat. 2006 May;19(4):304-11.PMID: 16059926 [PubMed - indexed for MEDLINE]
Factors affecting meniscal extrusion: correlation with MRI, clinical, and arthroscopic findings. Abstract Abstract
The existence of meniscal extrusion is well known in the natural history of the osteoarthritic knee. However, extruded menisci are also seen in non-pathologic knees. To ascertain the prevalence of meniscal extrusion in non-arthritic patients, the MRIs of 100 knees were prospectively studied. The data were correlated both with clinical and operative arthroscopic findings. The results showed 68.5% of the medial menisci to have some degree of extrusion, averaging at 28% of the meniscal size. While the lateral meniscus were extruded in 18.8% of cases at an average of 15% of the meniscal size. Furthermore, a relationship between the anterior insertion variant of the anterior medial meniscus and meniscal extrusion was found (P=0.001) in this series. The results suggest meniscal extrusion to be much more common in non-arthritic knees than previously estimated. The results also suggest that when the anterior horn of the medial meniscus inserts anteriorly in the tibial plateau, the meniscus tends to be extruded. It must be kept in mind that one of the limitations of this work is that the MRIs are taken in a non-weightbearing position.
Knee Surg Sports Traumatol Arthrosc. 2006 Apr;14(4):394-8. Epub 2005 Sep 15.PMID: 16163556 [PubMed - indexed for MEDLINE]
Bilateral hypoplasia of the medial meniscus. Abstract Abstract
Only a few cases of the nearly unknown hypoplastic meniscus abnormality have been described. A case report of an incidental finding in a young female with a bilateral hypoplastic medial menisci is presented and, as far as we know, is the first report of bilateral hypoplasia of the medial meniscus in the literature.
Knee Surg Sports Traumatol Arthrosc. 2006 Feb;14(2):112-3. Epub 2005 Jun 21.PMID: 15968531 [PubMed - indexed for MEDLINE]
Decreased metalloproteinase production as a response to mechanical pressure in human cartilage: a mechanism for homeostatic regulation. Abstract Abstract
Articular cartilage is optimised for bearing mechanical loads. Chondrocytes are the only cells present in mature cartilage and are responsible for the synthesis and integrity of the extracellular matrix. Appropriate joint loads stimulate chondrocytes to maintain healthy cartilage with a concrete protein composition according to loading demands. In contrast, inappropriate loads alter the composition of cartilage, leading to osteoarthritis (OA). Matrix metalloproteinases (MMPs) are involved in degradation of cartilage matrix components and have been implicated in OA, but their role in loading response is unclear. With this study, we aimed to elucidate the role of MMP-1 and MMP-3 in cartilage composition in response to mechanical load and to analyse the differences in aggrecan and type II collagen content in articular cartilage from maximum- and minimum-weight-bearing regions of human healthy and OA hips. In parallel, we analyse the apoptosis of chondrocytes in maximal and minimal load areas. Because human femoral heads are subjected to different loads at defined sites, both areas were obtained from the same hip and subsequently evaluated for differences in aggrecan, type II collagen, MMP-1, and MMP-3 content (enzyme-linked immunosorbent assay) and gene expression (real-time polymerase chain reaction) and for chondrocyte apoptosis (flow cytometry, bcl-2 Western blot, and mitochondrial membrane potential analysis). The results showed that the load reduced the MMP-1 and MMP-3 synthesis (p < 0.05) in healthy but not in OA cartilage. No significant differences between pressure areas were found for aggrecan and type II collagen gene expression levels. However, a trend toward significance, in the aggrecan/collagen II ratio, was found for healthy hips (p = 0.057) upon comparison of pressure areas (loaded areas > non-loaded areas). Moreover, compared with normal cartilage, OA cartilage showed a 10- to 20-fold lower ratio of aggrecan to type II collagen, suggesting that the balance between the major structural proteins is crucial to the integrity and function of the tissue. Alternatively, no differences in apoptosis levels between loading areas were found--evidence that mechanical load regulates cartilage matrix composition but does not affect chondrocyte viability. The results suggest that MMPs play a key role in regulating the balance of structural proteins of the articular cartilage matrix according to local mechanical demands.
Arthritis Res Ther. 2006;8(5):R149.PMID: 16972994 [PubMed - indexed for MEDLINE]Free PMC Article
Iliotibial band friction syndrome after anterior cruciate ligament reconstruction using the transfix device: report of two cases and review of the literature. Abstract Descargar PDF Abstract
The use of hamstrings is increasing as a treatment for anterior cruciate ligament (ACL) injuries. There are a lot of new devices and techniques that try to fix the graft without causing further injury or increased morbidity. We report two cases in relation to the transfix device for reconstructing the ACL. The first case is a 38-year-old female who was treated with an autologous hamstring graft for chronic ACL instability brought on by a sport trauma. The patient developed iliotibial band friction syndrome 3 months after the operation. MRI showed incorrect positioning and a rupture of the femoral bio-absorbable cross-pin. The hamstring graft always had good fixation and did not produce instability of the knee. We removed the cross-pin fragment in a second surgery and the patient returned to her daily lifestyle after 3 weeks. The second case is a 52-year-old female with a painful and unstable knee due to a previous lateral meniscectomy and failure of an ACL reconstruction. We performed an ACL reconstruction with an autologous hamstring graft and a lateral meniscus transplantation. Some months after the procedure she also developed this syndrome. MRI showed the same features as shown in the first case and a second surgery was needed. To our knowledge this clinical and technical problem has not been previously described.
Knee Surg Sports Traumatol Arthrosc. 2006 Jun;14(6):586-9. Epub 2005 Dec 21.PMID: 16369856 [PubMed - indexed for MEDLINE]
Influence of autograft removal on rabbit patellar tendon length. Abstract Descargar PDF Abstract
Twelve adult New Zealand white rabbits were randomly divided into two groups. In group 1, 30% of the central mass of the right patellar tendon was removed. In group 2, 60% was removed. The left knees served as controls. The animals were killed 1 year later. The patella-patellar tendon-tibial tuberosity units of all knees were studied using histological and morphometric analysis. In both groups, the tendons had lengthened. Lengthening average was 2.50 mm in group 1 and 8.17 mm in group 2. In both groups, histology revealed poor alignment of the collagen fibres and high cellularity, although the findings in group 1 were nearer the normal histological pattern. The results suggest that removal of significant portions of the patellar tendon leads to lengthening of the resulting tendon. In clinical practice, it seems prudent to pay attention to the dimensions of the patellar tendon when harvesting a graft.
Int Orthop. 2004 Feb;28(1):7-10. Epub 2003 Mar 26.PMID: 14770268 [PubMed - indexed for MEDLINE]
Tomographic study of the arthroscopic approaches to the hip joint. Abstract Descargar PDF Abstract
The anatomic depth of the hip joint has long been one of the limiting factors in the development of arthroscopy of this particular joint. A major factor would seem to be variation in body size. The main purpose of this study was to quantify the distance between the joint and the skin in usual arthroscopic approaches. TYPE OF STUDY: In vivo radiologic study using computed tomography.
METHODS: We studied the distance from the center of the acetabulum to the skin. The lines that we studied correspond to the paratrochanteric, the anterolateral, and anterior arthroscopic entry points.
RESULTS: Although notable differences exist from one individual to another, the average values of the aforementioned are 12.4 cm, 11.2 cm, and 9.8 cm, respectively. The distances of these portals are greater in women than in men (P <.05), and there is no statistically significant relationship to age. CONCLUSIONS: The results of the present work suggest that surgical tools needed for arthroscopy of the hip should be more than 16 cm long to guarantee performing hip arthroscopy comfortably in more that 95% of the population.
Arthroscopy. 2003 Apr;19(4):368-72.PMID: 12671619 [PubMed - indexed for MEDLINE]
Learning curve of arthroscopic hip surgery Abstract Abstract
BACKGROUND: Hip arthroscopy has become an increasingly used technique in orthopedic surgery; the learning curve of this procedure has been discussed recently. The purpose of this study is to assess the learning curve of arthroscopic hip surgery using the complications occurred during the surgery as an objective parameter to measure the outcomes. METHODS: Hip arthroscopic surgeries were performed. Patients were divided into two groups, group A corresponded to the learning curve of the first surgeon and group B includes the remaining surgeries. The demographic, surgical, functional and complications data for both groups were collected.
RESULTS: Group A: 30 patients were included, the traction time during surgery was a mean of 75 minutes (range: 45-120). Five complications occurred (16.6%), all of them related to transient neuropraxia of the pudendal nerve. Group B: 67 patients were included, traction time during surgery was a mean of 63 minutes (range: 35-90), 2 complications (2.9%) occurred. CONCLUSIONS: Before performing hip arthroscopy it is necessary to have knowledge of arthroscopic surgery and the regional anatomy, and to have received specific training, given that this technique involves a long learning curve.
Acta Ortop Mex. 2010 May-Jun;24(3):177-81. Spanish. PMID: 20836373 [PubMed - in process]
Fractures above and below a modular nail for knee arthrodesis. A case report. Abstract Abstract
Several techniques have been advocated for knee arthrodesis, and there has been an increasing interest in modular intramedullary nails in the recent last years. We report a case of femoral and tibial fractures at each end of a modular nail in a solidly fused knee 8 months after an arthrodesis.
Knee. 2005 Jun;12(3):231-3.PMID: 15911298 [PubMed - indexed for MEDLINE]
Combined fracture of the talus: Arthroscopic treatment. Abstract Abstract
The purpose of this article is to report the treatment and short-term results of a combined fracture of the talus treated arthroscopically. A 29-year-old man sustained an anterolateral osteochondral grade III fracture of the talus dome associated with a coronal fracture of the body of the talus. This injury was reduced and fixed arthroscopically using cannulated screws. The patient returned to his daily style of living after 3 months time. One year later, the patient remains asymptomatic. Radiography showed neither signs of osteonecrosis nor osteoarthritis of the talus at the 1-year follow-up. Therefore, arthroscopic surgery could be an alternative treatment for this kind of talus fracture.
Arthroscopy. 2001 Apr;17(4):418-21.PMID: 11288018 [PubMed - indexed for MEDLINE]
- Histological diagnosis and tibial neuromas. J Bone Joint Surg Am. 2001 Mar;83-A(3):461. No abstract available. PMID: 11263651 [PubMed - indexed for MEDLINE]
Ring-shaped lateral meniscus. Abstract Descargar PDF Abstract
The existence of abnormal-shaped menisci has been long recognized. The presence of discoid menisci in the human knee is considered to be a congenital malformation with a very low rate of incidence except in Asian populations. Since the publication of Watanabe's Atlas, three types of lateral meniscal abnormalities are generally accepted: the complete and incomplete discoid, as well as the Wrisberg-ligament type meniscus. The present case is the second description of a ring-shaped meniscus on the lateral side of the knee and we propose that this variant be included as a fourth variant in a future classification.
Arthroscopy. 1998 Jul-Aug;14(5):502-4.PMID: 9681543 [PubMed - indexed for MEDLINE]
Osteochondritis dissecans: a historical review and its treatment with cannulated screws. Abstract Descargar PDF Abstract
The etiology of osteochondritis dissecans and the results of treating the early stages with arthroscopic fixation using cannulated screws is discussed. Arthroscopic surgery was performed on 14 patients with osteochondritis dissecans, and the osteochondral fragment was fixed with one or two screws. A second arthroscopic procedure was necessary to assess the lesion and remove the screws. Ambulation without weight bearing is allowed during the first 2 months postoperatively. Full range of motion is encouraged. The results indicate that all patients returned to their previous sport 3-11 months postsurgery. The authors conclude that fixation with cannulated screws is the ideal method of treating osteochondritis dissecans when the osteochondral fragment is still in its bed.
Arthroscopy. 1993;9(6):675-84.PMID: 8305105 [PubMed - indexed for MEDLINE]