Outcomes of the Different Types of Total Knee Arthroplasty with the Identical Femoral Geometry

PURPOSE: There are controversies around the role of the posterior cruciate ligament and the effect of design modifications for high flexion in total knee arthroplasty (TKA). So, we compared the clinical outcomes of the cruciate retaining (CR), posterior stabilized (PS), and high flexion posterior stabilized (F-PS) designs in TKA with identical femoral geometry. MATERIALS AND METHODS: One hundred seventy nine knees with 3 different types of prostheses after a minimum 5-year follow-up were enrolled in this retrospective study: 45 with CR, 40 with PS and 94 with F-PS. The mean ages of these groups were 65.7, 67.2, and 67.5, and the mean durations of follow-up were 8.1, 8.0, and 6.8 years, respectively. We compared the range of motion, functional outcomes, and radiographic measurements at the 2-year follow-up and last follow-up. RESULTS: The maximal flexion angle was significantly lower in the CR group than the F-PS group at the 2-year follow-up. However, there was no significant difference at the last follow-up. Functional outcomes and survival rate of the three groups were similar at the last follow-up. CONCLUSIONS: Three different types of TKAs (CR, PS and F-PS) with identical femoral geometry showed similar mid-term outcomes with regard to the range of motion, functional outcomes and survival rate.

Comparison of Posterior-Cruciate Retaining versus Substituting P.F.C. Total Knee Arthroplasty (A Randomized Study) / 대한정형외과학회잡지

PURPOSE: To compare the functional results of posterior cruciate-retaining (PCR) and posterior sub- stituting (PS) replacement in patients undergoing primary total knee arthroplasty (TKA) for osteoarthritis. MATERIALS AND METHODS: A randomized controlled study was carried out to compare the clinical and radiological outcomes of PCR and PS primary P.F.C.(R) TKA. One hundred and sixty eight patients (188 cases), who had a primary diagnosis of osteoarthritis, and an intact functioning posterior cruciate ligament, were enrolled in this study. The patients were randomized regardless of the level of posterior cruciate ligament preservation. One hundred and eighty eight cases had a minimum 6-year follow-up, which included 96 and 92 cases in the PCR and PS groups, respectively. RESULTS: The Knee Society Score, the Hospital for Special Surgery (HSS) knee rating scores, average flexion contracture and radiologic alignment improved significantly, but there were no significant difference between the two groups. On the other hand, the mean postoperative flexion angles in the PCR and PS knees increased from 114.7degrees to 121.2degrees and 119.3degrees to 131.3degrees, respectively (p<0.05). CONCLUSION: There were no significant differences between PCR and PS TKA in the follow-up knee scores. However, the level of postoperative improvement in further flexion was better in the PS group.