In vivo three-dimensional determination of the effectiveness of the osteoarthritic knee brace: a multiple brace analysis.

P revious kinematic studies on the effects of knee braces have concentrated primarily on the anterior cruciate ligament and the effects of bracing to stabilize the knee that has a deficiency of this ligament1-23. The majority of those studies have concentrated on the analysis of functional knee braces with use of arthrometers2,3,5-8,10-15. Other studies have concentrated on the analysis of femorotibial translation through the use of roentgen stereophotogrammetric analysis techniques4,9,16,17, subjective evaluation of bracing by categorizing pain and functional ability18-22, and the determination of the effectiveness of different types of knee braces, such as cast bracing23-26. Although minimal research evaluating the efficiency of off-loading braces for the treatment of unicompartmental arthritic degeneration has been performed, a previous study with an initial fluoroscopic analysis determined that bracing is an effective treatment for osteoarthritis of the knee in nonobese patients under weight-bearing conditions27. In that investigation of a single type of brace, the results were not assessed for three-dimensional motion and the study did not determine whether different types of osteoarthritic knee braces would perform well under similar conditions. The objective of the present study was to analyze subjects with symptomatic unicompartmental osteoarthritis under in vivo, dynamic weight-bearing conditions with use of video fluoroscopy28,29 to determine whether five different off-loading knee braces provide separation of the medial femoral condyle from the tibial plateau, thus avoiding excessive loads on the degenerated compartment. Fig. 1 Subject performing normal gait on a treadmill without a brace ( a ) and with a brace ( b ). W ith institutional review board approval, five subjects with substantial medial compartment osteoarthritis of the knee who …