Effect of bracing on patellar kinematics in patients with patellofemoral joint pain

Purpose: Bracing is commonly used to correct patellar malalignment syndrome s. However, there are little objective data documenting the effect of such supports on patellofemoral joint relationships. The purpose of this study w as to assess the effectiveness of an elastic patellofemoral sleeve brace in altering patellar tracking in subjects with patellofemoral pain. Methods: Ten female subjects (12 patellofemoral joints) between the ages of 17 and 4 6 participated in this study. Ail subjects had a diagnosis of patellofemora l pain and demonstrated lateral patellar tracking based on magnetic resonan ce imaging (MRI) assessment. Each subject underwent kinematic MRI of the pa tellofemoral joint through a range of 45 to 0 degrees of knee flexion again st a resistance of 15% body weight. imaging was performed with and without a patellofemoral joint brace (Bauerfeind Genutrain P3 brace, Atlanta, GA). Measurement of medial/lateral patellar displacement, medial/lateral patella r tilt, and the depth of the trochlear groove (sulcus angle) were obtained with midpatellar image sections at 45. 36, 27, 18, 9 and 0 degrees of knee flexion. Results: No statistically significant differences in medial/latera l patellar displacement or tilt were found between braced and unbraced tria ls across all knee flexion angles (P < 0.05). A small but statistically sig nificant increase in sulcus angle was found across all knee flexion angles with the braced trials (P > 0.05). Conclusions: These results do not suppor t the hypothesis that the brace used in this study corrects patellar tracki ng patterns in subjects with patellofemoral pain. However: the increased su lcus angle indicates a change in patella position within the trochlea. It i s possible that the clinical improvements seen with bracing may be the resu lt of subtle differences in joint mechanics and not gross changes in alignm ent.