A randomized trial of patellofemoral bracing for treatment of patellofemoral osteoarthritis

Purpose: The number of effective knee osteoarthritis (OA) interventions, especially those tailored to specific compartmental involvement, are small. The objective of this study was to determine the efficacy of a realigning patellofemoral (PF) brace in improving pain and function among persons with symptomatic lateral PF OA.

Method: We conducted a double blind, randomized crossover trial of a realigning PF brace for persons with lateral PF OA. Participants had lateral PF OA with anterior knee symptoms on most days of the month, lateral PF joint space narrowing, and radiographic evidence of a definite osteophyte in the PF joint. We compared two treatments: (1) Control treatment consisting of a BioSkin Q Brace with patellar realigning strap removed; and (2) Active treatment consisting of a realigning BioSkin Q Brace with the strap applied. For each participant, the trial lasted 18 weeks, including 6 weeks each of active and control treatment period separated by a 6-week washout period. The order of treatments was randomized. The primary outcome was change in knee pain on the visual analog scale (VAS). Secondary outcomes included WOMAC pain, function, and stiffness. An unstructured correlation matrix for observations within participants was used in generalized estimating equation fitting to derive a linear regression model that expressed the relation between the intervention and change in VAS pain.

Results: 80 participants (63 F) with a mean age and body mass index of 61 years and 28 kg/m(2), respectively, were randomized by order of treatment. A model examining the main effects for change in VAS knee pain (0-100) demonstrated no significant treatment effect (-0.68 VAS units, 95% CI: -6.2, 4.8 units, P=0.81) and no differential carryover effect. There was also no significant difference between active and control treatments for WOMAC pain, function, or stiffness outcomes.

Conclusion: The effects of a specific realigning PF brace are not of clinical or statistical significance.