Unequal leg length and osteoarthritis link is uncertain

The risk of progressive knee radiographic osteoarthritis (OA) is significantly higher in patients with limb length inequality (LLI); the risk of incident knee or hip radiographic OA and progressive hip radiographic OA, progressive chronic knee symptoms, and incident and progressive chronic hip symptoms is nonsignificantly higher. LLI may be a marker of more rapid progression of radiographic knee OA rather than a true predictor of such progression.

Golightly and associates examined paired radiographs of the knee and hip in 1583 and 1453 community-based OA study participants, respectively. Of these, 90 and 79 patients with knee or hip OA, respectively, had LLI of 2 cm or greater.

Compared with others, persons with LLI had a 20% to 30% higher hazard of incident hip or knee radiographic OA and a 34% to 83% higher hazard of progressive radiographic OA. However, these findings were significant only for progressive knee radiographic OA. Hip or knee radiographic OA was less likely to occur in longer limbs than in shorter limbs.

The authors noted that future studies are needed to examine these conditions over a longer period and to further investigate the role of lower extremity radiographic OA as a predictor of LLI.