COMPARATIVE RESULTS OF TOTAL KNEE REPLACE MENT WITH OR WITHOUT PRESERVATION OF THE POSTERIOR CRUCIATE LIGAMENT

Purpose of the study This study was undertaken to assess the functiona l repercussion of retention or sacrifice of the posterior cruciate lig ament in total knee replacement. Material Two homogeneous randomised s eries of 24 cases were matched. They concerned primary total knee arth roplasty for osteoarthritis using the same prosthetic design, In case of sacrifice of the posterior cruciate ligament, the prosthesis includ ed a substitution system constituting the only difference between the two types of implants (the design of trochlea, femoral condyle and tib ial plateau were identical). Methods Functional assessment was perform ed according to the Hospital for Special Surgery score, at a minimal f ollow up of 12 months. The Student ''t'' Test was used for statistical analysis. Results In cases with posterior cruciate retention,the mean HSS score was 86,6. In postero-stabilised cases. this score was 87,7: a non significant difference. The mean range of flexion was 108 degre es for the retaining cases versus 113 degrees for the postero-stabilis ed ones: a non significant difference. Discussion The functional outco me seems to be the same whether a postero-stabilised or a posterior cr uciate retaining total knee prosthesis was used. The latter technique requires more care for ligament balancing, tibial cuts and exposure. C onclusion The authors believe that there is no benefit to expect at mi d-term follow up from retaining the posterior cruciate ligament in tot al knee replacement.