INTRA-ARTICULAR MIGRATING BONE MARROW EDEMA SYNDROME OF THE KNEE

Abstract

Bone marrow edema syndrome (BMES) is a common cause of severe bone and joint pain. Intra-articular migrating of bone marrow edema syndrome (BMES) is a very unusual pattern of disease which has been previously described in only a few cases and may raise the suspicion of an aggressive disease.

We reviewed 8 patients (4 female, 4 male) with unilateral BMES located in the knee. The patients were aged 39–56 years (mean 50.2). In all the patients bone marrow edema (BME) found in the primary magnetic resonance imaging (MR imaging) shifted within the same joint, i.e. from the medial to the lateral femoral condyle or to the neighboring bone. Conservative therapy including limited weight-bearing for a period of three weeks was provided for seven patients after initial detection of BMES and one patient underwent surgical core decompression twice.

The final MR investigation performed on average 8 months after baseline (range, 7–11 months) showed full resolution of BMES in 6 patients. One patient had small residual edematous bone areas. No quadrant was newly affected. Improvement of the MR imaging pattern was correlated with the clinical outcome in all patients. The severity of effort-induced pain (VAS) was reduced from 7.5 (2.0–10.0) at baseline to 5.9 (2.4–7.9) after 3 months and to 0.6 (0–0.9) after the final examination. Pain at rest (VAS) diminished from 3.9 (1.5–7.8) to 2.8 (1.4–6.0) after 3 months and to 0 at the final follow-up. All patients became asymptomatic after a mean of 9 months (6–11).

Intra-articular migrating BMES is a condition seen very rarely. The disease is self-limited so that conservative therapy can be recommended.