Bone Marrow Lesions Prevalent and Associated With Pain in Knee Osteoarthritis

Bone marrow lesions (BML) are highly prevalent in patients with knee osteoarthritis (OA). They are significantly associated with pain on climbing stairs.

Ip and colleagues conducted a population-based study of 255 symptomatic patients with knee OA. Patients were evaluated with radiography and with MRI at 6 joint sites and classified into no OA (NOA), preradiographic OA (PROA), and radiographic OA (ROA) subgroups. BML were scored on a scale of 0 to 3 (none, mild, moderate, severe), and BMLsum (the sum of 6 scores) and BMLmax (the worst score at any region) were determined. The Western Ontario and McMaster Universities OA Index (WOMAC) was used for pain assessment.

Median BMLsum and BMLmax were significantly different between OA groups; severity of BMLmax increased with increasing OA stage. BML were present in 11%, 38%, and 71% of patients in the NOA, PROA, and ROA groups, respectively. Duration and frequency of knee pain were highest in the ROA group. No association was seen for BMLsum or BMLmax versus Total WOMAC Pain or Pain on Walking.

The authors noted that the inclusion of the full spectrum of disease in this symptomatic population was unique and allowed for an evaluation of BML in PROA.