There are various approaches for total knee arthroplasty (TKA). On the basis of an analysis of the clinical results, it has been demonstrated that the midvastus approach (MV) is advantageous in the early postoperative period compared to the medial parapatellar surgical approach (MPP). The aim of this investigation was therefore to investigate whether the clinical advantage of MV is reflected in the functional outcome. This single blinded, prospective, randomised study was based on a power analysis. Selected randomised patients (MPP = 10, MV = 11) were examined using an instrumental gait analysis system (VICON) preoperatively, and 5 weeks (5 W) and 6 months (6 M) after implantation. The results were compared to a healthy control group (CG = 53). Besides clinical parameters, the primary objective of this study was to measure objective gait parameters; the secondary objective was to record self-assessment (Knee Society score, WOMAC). In both treatment groups, the measurements improved during the investigation period, although most parameters did not reach the CG levels. MV gave better values for the kinetic parameters sagittal knee moment (5 W) and knee power (5 W, 6 M), as well as self-assessment (WOMAC, 6 M). Other clinical parameters were similar in the two groups. In summary, in the early postoperative period, MV led to advantages in function and in subjective behaviour in daily life. From the biomechanical point of view, the MV approach is preferable.
Georg Thieme Verlag KG Stuttgart · New York.