Valgus knee braces used in conjunction with specialized footwear reduced pain from medial tibiofemoral osteoarthritis by about 20% in a 30-week controlled trial, perhaps the most rigorous investigation of realignment treatment for knee osteoarthritis to date.
In a trial of randomized crossover design, 80 patients either wore a valgus knee brace (Oadjuster) plus customized neutral foot orthoses and motion-control shoes or a neutral knee brace (Montana) plus flat, nonsupportive foot orthoses and flexible mid-sole shoes for 12 weeks. They next went without treatment for 6 weeks, and then were crossed over to the alternative treatment for another 12 weeks.
Scores on the WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) pain scale were a mean of 1.82 units (95% confidence interval, –3.05 to –0.60; P value less than .004) lower when patients wore the valgus brace instead of the neutral brace. Overall, use of the valgus brace and orthoses reduced their pain by 20% from its baseline level. WOMAC function scores were 2.90 units lower (95% CI, –6.60 to 0.79) as well, but the finding was not significant (P value .12).
"We have demonstrated that the application of realignment treatment ... leads to a statistically significant improvement in knee pain compared to a placebo intervention," concluded lead author and rheumatologist Dr. David Hunter, professor of medicine at the University of Sydney and his colleagues at the New England Baptist Hospital in Boston (Ann. Rheum. Dis. 2012 Feb. 29 [doi: 10.1136/annrheumdis-2011-200728]).
It’s not the first time valgus unloader braces have been shown to help medial knee osteoarthritis (OA). However, brace adherence and lack of adequate control treatments may have skewed findings from previous trials. There was a "need for an appropriately powered and well-controlled trial on the effect of valgus knee bracing on persons with medial knee OA. We were adequately powered to detect a clinically meaningful treatment effect," the researchers noted.
On average, patients wore their braces for more than 3 hours each day. Their mean age was 62 years, and mean body mass index 34 kg/m2; most were women. Patients were ambulatory without assistance but on most days had knee pain, aching, or stiffness. Their baseline pain score was 9.2 on the 20-point WOMAC scale. Radiographs confirmed osteophytes and predominantly medial tibiofemoral OA.
Patients in the trial were new to prescription knee braces and customized orthotics. To help control for the placebo effect – strong in OA trials – they weren’t told that the valgus brace was the active treatment.
Despite better pain control, however, the active treatment was more problematic. Sixteen patients had a hard time keeping the valgus brace in place, a problem for only four with the neutral brace. Seven patients said the motion-control shoes were painful. Just one said the flexible midsole control shoes hurt.
The researchers included the shoes and inserts because "even with appropriate valgus bracing, large mechanical stresses on the knee can persist, suggesting that the addition of other interventions to further improve limb alignment may be of therapeutic value," they noted.
In all, 24 patients (30%) dropped out of the study. Some were lost to follow-up, while others scheduled joint replacements or didn’t comply with treatment. An intent-to-treat analysis was used to reduce the impact.
DonJoy supplied the braces, and New Balance supplied the shoes and inserts. The companies otherwise were uninvolved in the project, which was funded by the National Institute on Disability and Rehabilitation Research. The researchers reported no relevant financial conflicts of interest.