AIM. Failure of a primary anterior cruciate ligament (ACL) reconstruction is associated with poor functional outcomes even after revision surgery. The aim of this study is to identify early predictors for failure, so that it may aid in recognition of at-risk patients. METHOD. An observational study was conducted of 623 patients undergoing primary ACL reconstruction by a single surgeon over a 72 month period. Patient and procedure related parameters including age, gender, BMI, time to surgery, graft size, fixation methods, meniscal and chondral injuries, meniscal surgery, radiological parameters and post-operative IKDC scores. Logistic regression modeling was employed to identify those factors which were statistically significant for failure. RESULTS. We identified 14 patients who experienced failure of their ACL graft. The causes for failure included trauma (9), infection (2), arthrofibrosis (1), biological (1) and recurrent instability (1). Univariate analysis established a significant relationship between age at time of injury (p<0.001), BMI (p=0.001), time to index procedure (p<0.001), screw length (p=0.04) and early post-operative IKDC score (p<0.001). Multivariate analysis demonstrated all factors stated except screw length to be important for predicting failure for ACL reconstruction. CONCLUSIONS. The rate of graft failure is lower than has been those quoted in the literature. We have identified those patients who are at high risk of rupturing a reconstructed primary ACL graft. Careful monitoring and functional modification of high-risk patients may be indicated to prevent failure. This study identifies predictive factors of failed ACL reconstruction. Age at time of injury, BMI, time to surgery, post-operative IKDC scores were found to be associated with failure

Chondral injuries of the knee are extremely common and present a unique therapeutic challenge due to the poor intrinsic healing of articular cartilage. These injuries can lead to significant functional impairment. There are several treatment modalities for articular osteochondral defects, one of which is autologous chondrocyte implantation. Our study evaluates the mid to long term functional outcomes in a cohort of 828 patients who have undergone an autologous chondrocyte implantation procedure (either ACI or MACI), identifying retrospectively factors that may influence their outcome. The influence of factors including age, sex, presence of osteoarthritis and size and site of lesion have been assessed individually and with multivariate analysis. All patients were assessed using the Bentley Functional Score, Visual Analogue Score and the Cincinnati Functional Score. Assessment were performed pre-operatively and of their status in 2010. The majority of patients had several interim scores performed at varying intervals. The longest follow-up was 12 years (range 24 to 153 months) with a mean age of 34 years at time of procedure. The mean defect size was 486 mm2 (range 64 to 2075 mm2). The distribution of lesions was 51% Medial Femoral Condyle, 12.5% Lateral Femoral Condyle, 18% Patella (single facet), 5% Patella (Multifacet) and 6% Trochlea. 4% had cartilage transplant to multiple sites. 30% failed following this procedure at a mean time of 72 months. 52% patients stated a marked improvement in their functional outcomes within the first two years. 49% stated an excellent result following their procedure. High failure rate was noted in those with previous cartilage regenerative procedures, transplants occurring on the patella, particularly if involving multifacets. Multiple site cartilage transplantation was also associated with a high failure rate. Autologous chondrocyte implantation is an effective method of decreasing pain and increasing function, however patient selection plays clear role in the success of such procedure