Published: Oct 30, 2013
By Nancy Walsh, Staff Writer, MedPage Today
Full Story: http://www.medpagetoday.com/MeetingCoverage/ACR/42576
Action Points
- Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.
SAN DIEGO — Patients with knee osteoarthritis (OA) who wore a patellofemoral brace for 6 weeks experienced decreases in pain and bone marrow lesions, a researcher said here.
On a 100-point visual analog scale (VAS), patients who wore the brace for an average of 7.35 hours per day had a “substantial” decline in pain of -18.16 points (95% CI minus 23.88-minus 12.44), whereas controls had only a slight change of -1.29 points (95% CI minus 6.39-3.80), reported David T. Felson, MD, of the University of Manchester in England, and colleagues.
That represented a highly significant between-group difference of 16.87 points (P<0.001), he said at the annual meeting of the American College of Rheumatology.
“There’s a pressing need for nonsurgical treatment options for knee OA, which is the most common form of arthritis,” he said.
There have been studies looking at disease-modifying treatments for hyaline articular cartilage, which changes very slowly in OA, but these have been large and expensive and there are no currently approved disease modifying drugs.
“In addition, mechanopathology, such as caused by malalignment and meniscal tears, may make it impossible to protect existing cartilage in at least some OA patients,” he said.
Bone marrow lesions have been identified in OA, and represent regions of bone that demonstrate hyperintense signals on MRI, as well as fibrosis, necrosis, and microfractures on histology.
This trauma is caused by increased focal contact stress across the knee joint during weight bearing.
Bone marrow lesions have been shown to predict later cartilage loss and to correlate with pain and its severity, so may be a viable treatment target in OA, Felson explained.
His group conducted a randomized trial that included 126 patients with daily knee pain.
Their average age was 55, slightly more than half were women, and mean body mass index was 31 kg/m2.
Average baseline score on the 100-point VAS was 65.
After 6 weeks, patients not wearing the brace showed a slight 5% increase in bone marrow lesion volume, while those using the brace had a 25% reduction.
Specifically, the no-brace group had an increase of 102.66 mm3 (95% CI minus 292.80-498.12) and the brace group showed a decrease of -554.92 mm3 (95% CI minus 964.02-minus 145.82, P=0.02).
In contrast, bone marrow lesion volume in a control joint — the tibiofemoral joint — showed no difference with the brace, indicating that the brace had a specific, localized effect, Felson said.
A limitation of the study was its short duration, and further assessments will be needed to evaluate potential long-term effects.
The authors reported no conflicts of interest.
Primary source: American College of Rheumatology
Source reference: Felson D, et al “A randomized trial of a brace for patellofemoral osteoarthritis targeting knee pain and bone marrow lesions” ACR 2013; Abstract 1694.