A PROSPECTIVE STUDY ON FUNCTIONAL OUTCOME IN POSTERIOR CRUCIATE RETAINING VERSUS POSTERIOR CRUCIATE SACRIFICING TOTAL KNEE ARTHROPLASTY

Background: Total knee arthroplasty has evolved over the past decades into a very much reliable surgical treatment foradvanced arthritis of knee. Total knee replacement has been shown to restore patient function and relieve pain anddeformity that results from knee arthritis. The success of a total knee replacement is determined by many factors likedegree of pain relief and functional outcome. The role of Posterior cruciate ligament in total knee replacement iscontroversial. The first is to retain the ligament and to preserve as much as possible of thenormal anatomy and function of the knee. Preservation of the ligament is thought to enhance stability, femoral rollback,mechanical advantage of the quadriceps muscle and proprioceptive properties. Theoretically it has been suggestedthat PCL retaining can increases the range of flexion and prevents posterior translation which reduces loosening andexcessive polyethylene wear by decreasing the shear stresses at the fixation surfaces. We conducted a prospectivestudy to compare resection with retention of PCL using a standard PCL–retaining cemented total knee replacement andassessed the functional outcome using functional knee scores and WOMAC score.Aims and Objectives: The aim of the study is to “prospectively compare the functional outcome between posteriorcruciate ligament retaining and posterior cruciate ligament sacrificing total knee arthroplasty.Materials and Methods: The study was done on 20 patients admitted to Hi-Tech Medical College & Hospital,Bhubaneswar. Scoring system formulated by the WOMAC Score, Knee Society Knee Score and Functional Knee Scorewere used to evaluate the patients before and after surgery. Both knee scores and functional scores are calculated witheach amounting to a total of 100 points and WOMAC Score with max of 96 points. All patients were evaluated postoperatively and followed up.Results: Analyzing the functional outcome it was found that all the patients in both the groups had significantimprovement in their knee score and the functional knee score. Analyzing the total Knee Scores, the average KneeSociety Score for the PS group was 85.80 and that of CR group was 75.60 and statistical analysis revealed a significantdifference in the the p-value in favour of Cruciate Sacrificing Prosthesis signifying that Cruciate Sacrificing Prosthesishas better functional outcome. The functional knee society also showed a marked improvement in all patients, for CSgroup FKS was 99.6 and for CR group it was 91.6.The WOMAC Score also showed a marked improvement. In CS groups itwas 24.6 and in CR it was 27.4. Statistical analysis showed a highly significant difference in favor of cruciate sacrificingprosthesis.Conclusions:Total Knee Arthroplasty in patients in whom posterior cruciateligament was sacrificed was found to have a better functional outcome as compared to the retaining group, which can bemainly attributed to the persistence of flexion deformity in cruciate retaining group. In Indian scenario where kneereplacement is done at a late stage of osteoarthritis, sacrificing the contracted posterior cruciate ligament has betteroutcomes as compared to retaining it.