Evaluating the potential synergistic benefit of a realignment brace on patients receiving exercise therapy for patellofemoral pain syndrome: a randomized clinical trial

Abstract

Background: It has been previously shown that exercise programs for patellofemoral pain syndrome (PFPS) can be supported by medially directed taping. Evidence supporting the use of patellar braces is limited because previous studies have been low quality. The aim of this study is to compare the outcomes of patients with PFPS after treatment with a medially directed patellar realignment brace and supervised exercise.

Methods: In a prospective randomized multicenter trial, 156 patients with PFPS were included and randomly assigned to 6 weeks of supervised physiotherapy in combination with the patellar realignment brace, or supervised physiotherapy alone. Outcome measures were the Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales, numeric analog pain scores, and the Kujala score at baseline, 6 weeks, 3 months, and 1 year after the start of therapy. The patient's self-reported perception of recovery was also assessed at these points.

Results: Both treatment groups showed a significant improvement in all outcome measures over the study period. After 6 and 12 weeks of therapy, patients in the brace group had significantly higher KOOS sub-scale scores, a higher mean Kujala score, and less pain while climbing stairs or playing sports. After 54 weeks a group difference could be only detected for the KOOS ADL sub-scale.

Conclusion: The use of a medially directed realignment brace leads to better outcomes in patients with PFPS than exercise alone after 6 and 12 weeks of treatment. After 1 year of follow-up this positive effect diminished.

Keywords: Anterior knee pain; Chondromalacia patellae; Dynamic valgus; Functional malalignment; Patellar maltracking; Patellar orthosis; Patellar tape.

Fig. 1

The patellar realignment brace (Patella Pro, Otto Bock, Duderstadt, Germany). The sleeve of the brace applies a medially directed force on the patella

Fig. 2

Flow chart of the study design

Fig. 3

Pain assessed on a numerical analog scale. For all parameters a non-parametric distribution was found (Kolmogorov–Smirnov-test, p < 0.05). a In both groups pain with walking improved over time (Friedman-test, p < 0.001). No between-groups differences could be detected (U test, p ≥ 0.05). b Pain at rest improved in both groups (Friedman-test, p < 0.001). No between-groups differences could be detected at any time point (U test, p ≥ 0.05). c In both groups pain during stair climbing improved significantly over time (Friedman-test, p < 0.001). Significant between-group differences could be detected after 6 (U test, p = 0.002) and 12 (p = 0.003) weeks of intervention. d Pain during sports improved in both groups over time (Friedman-test, p < 0.001). Significant between-group differences could be detected after 12 weeks of intervention (U test, p = 0.003)

Fig. 4

Results of the five KOOS subscales. Non-parametric tests were used for all five KOOS subscales (Kolmogorov–Smirnov-test, p < 0.05). a KOOS symptoms: In both groups the KOOS symptoms sub-score increased significantly (Friedman-test, p < 0.001). Significant between-group differences could be detected after 6 (U test, p < 0.001) and 12 (p < 0.001) weeks of intervention. b In both groups the average KOOS pain values increased from T0 to all three follow-up examinations (Friedman-test, p < 0.001). Significant between-group differences could be detected after 6 (U test, p < 0.001) and 12 weeks (p < 0.001) of intervention. c In both groups, the KOOS ADL sub-score increased over all time points (Friedman-test, p < 0.001). Significant between-group differences could be detected after 6 (U test, p = 0.002), 12 (p < 0.001) and 54 weeks (p = 0.034) of intervention. d In both groups, the KOOS sports/rec sub-score increased over all follow-up time points (Friedman-test, p < 0.001). Significant between-group differences could be detected after 6 (U test, p = 0.038) and 12 (p = 0.001) weeks of intervention. e In both groups, the KOOS QoL sub-score increased over all follow-up time points (Friedman-test, p < 0.001). Significant between-group differences could be detected after 6 (U test, p = 0.001) and 12 (p = 0.011) weeks of intervention

Fig. 5

Kujala score. In both groups the Kujala-score increased over all three follow-up time points (Friedman-test, p < 0.001). Significant between-group differences were detected after 6 (U test, p = 0.029) and 12 (p = 0.037) weeks of intervention