Introduction. Partial meniscectomy, a surgical treatment for meniscal lesions, allows athletes to return to sporting activities within two weeks. However, this increases knee joint shear stress, which is reported to cause osteoarthritis. The volumes and locations of partial meniscectomy that would result in a substantial increase in knee joint stress is not known. This information could inform surgeons when a meniscus reconstruction is required. Aim. Our aim was to use a previously validated knee finite element (FE) model to predict the effects of different volumes and locations of partial meniscectomy on cartilage shear stress. The functional point of interest was at the end of weight acceptance in walking and running, when the knee is subjected to maximum loading. Method. An FE model of the knee joint was used to simulate walking and running, two of the most common functional activities. Forces and moments, obtained from the gait cycle of a 76.4 kg male subject, were applied at the tibia. Different sizes (0%, 10%, 30%, 60%) and locations (anterior, medial and posterior) of partial meniscectomies were simulated (Figure 1). Maximum cartilage shear stress was determined for the different meniscectomies. Graphs were plotted of the cumulative tibial cartilage volume subjected to stress values above specific thresholds. Results and analysis. Maximum shear stress values for the intact knee during walking were 2.00 MPa medially and 1.71 MPa laterally. During running these magnitudes rose to 3.48 MPa medially and 4.70 MPa laterally. For a 30% anterior, central and posterior meniscectomy during walking shear stress increased by 25.9%, 44.9% and 32.5% medially, and 12.4%, 25.7% and 17.8% laterally. During running shear stress increased by 9.6%, 8.3% and 7.1%, medially and 31.6%, 37.5% and 43.6% laterally. For a 60% meniscectomy, during walking shear stress increased by 47.2% medially and 31.8%, laterally. During running shear stress increased by 10.0%, medially and 51.8%, laterally. The percentage of cartilage volume exposed to shear stress levels above a specified threshold is illustrated in Figure 2 for different volumes and locations of partial meniscectomy. Discussion and conclusions. This is first study that has estimated the volume of cartilage exposed to specific stress thresholds in walking and running as a function of the amount and location of meniscectomy. Maximum shear stress was 100% higher at the end of weight acceptance in running compared to walking. Stress was higher in the lateral compartment during running while higher in the medial compartment during walking. This is because a valgus moment acts at the knee at the end of weight acceptance in running while a varus moment acts at the joint in walking. Clinical significance. The model developed from this research has potential for applications in planning meniscal surgeries and developing rehabilitation strategies for athletes. It could inform surgeons about the safe volume and location of partial meniscectomy that can be performed before meniscus reconstruction becomes necessary. Results of this study also highlight the importance of considering the effect of post-surgical outcomes following different common functional activities

Discoid meniscus (DM) is a congenital variant of the knee joint that involves morphological and structural deformation, with potential meniscal instability. The prevalence of the Discoid Lateral Meniscus (DLM) is higher among the Asians than among other races, and both knees are often involved. Meniscal pathology is widely prevalent in the adult population, secondary to acute trauma and chronic degeneration. The true prevalence in children remains unknown, as pathologies such as discoid menisci often go undiagnosed, or are only found incidentally. A torn or unstable discoid meniscus can present with symptoms of knee pain, a snapping or clicking sensation and/or a decrease in functional activity, although it is not known if a specific presentation is indicative of a torn DM. While simple radiographs may provide indirect signs of DLM, magnetic resonance imaging (MRI) and arthroscopy is essential for diagnosis and treatment planning. Asymptomatic patients require close follow-up without surgical treatment, while patients with symptoms often require surgery. Partial meniscectomy is currently considered the treatment of choice for DLM. For children are more likely to achieve better results after partial meniscectomy

INTRODUCTION:. To avoid the early onset of osteoarthritis after partial meniscectomy an effective replacement of injured meniscal tissue would be desirable. The present study investigates the behaviour of a new silk derived scaffold supplied by Orthox Ltd. (Abingdon, UK) in an in vivo sheep model. METHODS:. The scaffolds where derived from silk fibres by processing into an open porous matrix. Nine sheep (4 ± 1 years) underwent partial meniscectomy at the anterior horn of the medial meniscus followed by implantation of a scaffold. The unoperated contralateral stifle joint served as control. After six months the animals were sacrificed and the joints inspected for inflammation. The Young's modulus of the tibial cartilage, meniscus and scaffold was determined by indentation or confined compression tests. All tissues were fixed in formaldehyde for histology. The data were analysed by a Wilcoxon and Mann-Whitney-U-test. RESULTS:. The sheep were free of lameness 4 days p.o. The macroscopic analysis of the genual region and of the synovial membrane showed no signs of inflammation. This was confirmed by histological sections of synovial membrane, meniscus and scaffold. In histology, amorphous material, some fibroblast-like cell clusters and connective tissue formation was visible inside the pores of the scaffold. There were no statistically significant differences between the Young's moduli of the three measuring points in the operated and unoperated stifle joints. The meniscal tissue showed a higher modulus than the scaffolds. The scaffold's modulus significantly increased after three months implantation. DISCUSSION & CONCLUSIONS:. The presented silk scaffold withstood the loads occurring during the six months implantation period. It showed promising properties concerning biocompatibility and cartilage protection and its mechanical properties started to approach those of meniscal tissue

Introduction. Meniscal tears in middle-aged patients are common. There is a lack of consensus regarding the optimum management of these injuries. Although arthroscopic partial meniscectomy (APM) is a frequently performed surgical option, literature has failed to prove its effectiveness over conservative approaches. Materials and Methods. We retrospectively reviewed 102 middle-aged (age > 40 years) patients who had been treated for meniscal tears between January 2010 and December 2012. We followed these patients up telephonically to assess knee outcome satisfaction rates, any early (6 weeks) improvements in pain and knee function and their pre-morbid and post-treatment activity levels (Tegner Activity Scale). Results. There were 65 male and 37 female patients with an average age of 58 years (range 40–79). After their first consultation 72 patients were treated conservatively and 30 patients were treated with an APM. There were no reported complications following surgery. We managed to contact 87 patients who were followed up at an average of 17.5 months (range 5–34 months). Overall, 72.4% of patients managed were satisfied with their knee outcomes. APM had a 78.9% satisfaction rate and 67.3% of patients treated conservatively were satisfied. There were no significant differences in early or long term pain or knee function improvements between APM or conservative modalities. 89.7% of patients returned to the same or better activity levels after treatment. There was a 1.5 times greater risk of worse activity level following APM. There was a 79.3% satisfaction rate in patients who remained at the same activity level (p=0.00). Analysis showed 21 of the 72 conservatively treated patients failed this approach. APM was performed on 18 of them resulting in a 75% satisfaction rate for this group. Conclusion. APM and conservative management produce equivalently good results for meniscal tears in middle-aged patients. Delayed surgery does not negatively influence the outcome of these patients. NO DISCLOSURES

Purpose. To evaluate the results of quadrupled hamstring tendon autograft anterior cruciate ligament reconstruction with four fold Hamstring Tendon Graft using Transfix and Bioabsorbable Interference Screw Fixation. Study Design. Retrospective review. Methods. Sixty-five patients (66 knees) were retrospectively identified by chart review as having undergone quadrupled hamstring tendon autograft anterior cruciate ligament reconstruction, with four fold Hamstring Tendon Graft, using Transfix and Bioabsorbable Interference Screw Fixation. All patients underwent a minimum two-year follow-up. Results. Data were collected on 48 knees in 47 patients (73%) at an average 30.2 months (range 24 to 43) after surgery. Thirty-six patients (37 knees) returned for clinical evaluation (56% return) and subjective follow-up only was obtained in 11 patients (17%). The mean Lysolm knee score was 91 (range, 45 to 98), with a mean of 97 for the uninvolved knee. The mean Tegner activity score was 5.7 (range 3 to 7). The KT-1000 arthrometer mean side-to-side difference for manual maximum displacement was 2.03 mm (range -1 to 8). The mean International Knee Documentation Committee knee score was 83 (range 47 to 100). Patients who underwent associated partial meniscectomy or meniscal repair had significantly lower International Knee Documentation Committee scores than patients without associated procedures (P < 0.01). Conclusions. Quadrupled hamstring tendon autograft anterior cruciate ligament reconstruction with bioabsorbable interference screw fixation is comparable with other methods of anterior cruciate ligament reconstruction in terms of patient satisfaction, knee stability, and function

Early stabilisation after an anterior cruciate ligament (ACL) rupture reduces future meniscal injury. We may therefore expect protection of articular cartilage from ACL reconstruction, but this has yet to be shown. Our aim wasto determine the effect of meniscal injury on the long term risk of osteoarthritis (OA) following ACL reconstruction using Single Photon Emission Computed Tomography (SPECT, a 3 dimensional radionuclide scan). We studied a prospective series of 31 patients (mean age at injury of 29 years) who had bone-patellar tendon-bone ACL reconstruction for unstable, ACL deficient knees. Mean follow-up was 10 years (range 9-13). Patients were separated into two groups according to the status of their menisci at the time of ACL reconstruction, those with intact menisci in group 1 (n=15) and those who required partial meniscectomy in group 2 (n=16). The contra-lateral normal knee was used as a control. All knees were clinically stable with high clinical scores (mean Lysholm score 93 and mean Tegner activity score 6). In group 1 (intact menisci) only one patient (7%) had clinical symptoms of OA and was the only patient with increased uptake on SPECT compatible with early OA. In group 2 (partial meniscectomy), two had clinical symptoms of osteoarthritis, and five patients (32%) had increased uptake on SPECT compatible with early OA. None of the control knees had early OA on SPECT. The prevalence of OA 10 years post ACL reconstruction, using the most sensitive investigation available, is very low in patients who had intact menisci (7%), but increases 5 fold (32%) if a meniscal tear was present. We recommend early ACL reconstruction to preserve the menisci to minimise the long term risk of OA

Aims

The aim of this study was to investigate surgeons’ reported change of treatment preference in response to the results and conclusion from a randomized contolled trial (RCT) and to study patterns of change between subspecialties and nationalities.