• Rheumatology Clinical Trials
• Arthritis
• Metabolic Bone Disease

• Rheumatology
• Rheumatology Clinical Trials
• Arthritis
• Metabolic Bone Disease

Bone marrow lesions may represent a viable target in the treatment of osteoarthritis (OA). David T. Felson, MD, University of Manchester, Manchester, United Kingdom, described a randomized clinical trial in which a patellofemoral (PF) knee brace reduced both the volume of bone marrow lesions in the PF joint and PF-related knee pain.

Bone marrow lesions represent lesions in subchondral bone caused in part by focal stress in the OA knee joint. Focal contact stress across the joint during weight bearing can cause bone trauma that leads to bone marrow lesions. Bone marrow lesions predict later cartilage loss at the same anatomic location and correlate with pain and pain severity. For these reasons, and because bone marrow lesion volumes fluctuate substantially in as little as 6 weeks [Felson DT et al. Osteoarthritis Cartilage 2012], bone marrow lesion volume appears to be a good short-term structural outcome measure in OA trials, said Prof. Felson. PF bracing can increase contact area in the PF joint [Powers CM et al. Clin J Sports Med 2004], with the potential to reduce contact stress and shrink bone marrow lesions, he said, in explaining the rationale for a study of bracing in the disease.

Patients aged 40 to 70 old (n=126) with daily knee pain ≥40 mm on a 1- to 100-mm visual analog scale (VAS) during a PF activity (eg, climbing or descending stairs, kneeling, prolonged sitting or squatting) for 3 months, a radiographic Kellgren-Lawrence Grade 2 or worse in the PF joint or PF OA worse than tibiofemoral disease, and confirmed PF joint tenderness on clinical examination were randomized to 6 weeks of treatment with a PF brace or no treatment.

The primary symptom outcome was the change in pain as measured on the VAS during nominated aggravating activity. The primary structural outcome was bone marrow lesion volume in the PF joint as assessed on contrast-enhanced magnetic resonance imaging. Tibiofemoral bone marrow lesion volume served as an untreated control region. In the treatment group, braces were worn for a mean of 7.35 hours per day. Five patients in the bracing group and one in the no-treatment group withdrew from the trial before completion.

In the bracing group, pain on the VAS during the nominating activity decreased by 18.16 mm, compared with a 1.29-mm reduction in the no-treatment group (p<0.001). Improvements in the Knee Injury and Osteoarthritis Outcome Score pain subscale and activities of daily living subscale were also significantly superior in the bracing group (p=0.02 for each vs no treatment; Table 1).

PF bone marrow lesion volume decreased by a mean of 554.92 mm³ in the bracing group, compared with a mean increase of 102.66 mm³ in the no-treatment group (p=0.02). There was no significant difference between groups in the mean change in tibiofemoral bone marrow lesion volume or in synovitis volume.

The reduction in the size of bone marrow lesion volumes in the PF but not the tibiofemoral joint is consistent with a compartment-specific effect of the brace, concluded Prof. Felson.

• © 2013 MD Conference Express®