The relationship between lateral epicondyle morphology and iliotibial band friction syndrome: A matched case-control study.

BACKGROUND: Iliotibial band friction syndrome (ITBFS) is an overuse injury with pain at the level of the knee lateral epicondyle. We sought to determine whether there is greater knee lateral epicondyle prominence among patients with ITBFS versus matched controls.

METHODS: Seventy five patients with ITBFS and 75 age-, height-, and sex-matched controls (n = 150 total patients) with knee magnetic resonance imaging from 2015 to 2017 were included. All cases had a diagnosis of ITBFS and a lack of other identified lateral knee injuries on magnetic resonance imaging. Controls had medial knee pain with medial meniscus tear on MRI and no clinical evidence of ITBFS. Lateral knee epicondyle height in millimeters was measured.

RESULTS: Mean patient age was 39.1 years (SD 15.1), 57% were female, and mean height was 170.0 cm (SD 9.3) with no difference between cases and controls. Mean lateral epicondyle height for cases was 13.1 mm (SD 1.6) and for controls was 12.2 (SD 1.4) with a mean difference of 0.9 mm (95% CI 0.4-1.3 mm) between matched pairs (p < 0.001). Mean epicondyle height:condylar AP width ratio was 0.211 (SD 0.023) for cases and 0.198 (SD 0.020) for controls with a mean difference of 0.013 (95% CI 0.006-0.020) between matched pairs (p < 0.001).

CONCLUSIONS: There is a significant association between greater lateral epicondyle prominence and IT band friction syndrome, suggesting another anatomic risk factor for this multifactorial condition.