Acetabular dysplasia may be related to global joint hyperlaxity

Abstract

Purpose: Some patients with shoulder laxity complain of coxalgia without a history of trauma. We hypothesised that patients who have recurrent shoulder instability accompanied with generalised joint hyperlaxity tend to have acetabular dysplasia.

Methods: Pelvic radiographs of 26 young patients with hyperlaxity who had shoulder instability complaints without any history of hip joint trauma were evaluated by measuring their centre-edge angle (CEA) and acetabular angle (AA). In addition, Beighton generalised joint laxity tests were performed. All of the patients had shoulder pain and instability accompanied with hyperlaxity. We performed magnetic resonance imaging examination to show SLAP-Bankart lesions and pelvis anteroposterior X-rays to detect acetabular dysplasia.

Results: The average age of the study group was 26 ± 8.03 years (13-39). Six patients were female and 20 were male. When CEA (<22.6 degrees) was used as a criterion for acetabular dysplasia, the dysplasia rate of our patient group was 3.84 % for the right hip, 3.84 % for the left hip and 3.84 % overall. When AA (>42.2 degrees) was used as the dysplasia criterion, the dysplasia rate of patient group was 30.76 % for the right hip, 57.69 % for the left hip and 57.69 % overall.

Conclusions: CEA values were significantly lower (p = 0.009) and AA values were significantly higher (p < 0.001) in our study group than the previously-reported average values of the Turkish population. We think that acetabular dysplasia is more frequent in patients with hyperlaxity; further studies are needed to test this idea.

Keywords: Acetabular angle; Acetabular dysplasia; Centre-edge angle; Joint hyperlaxity; Shoulder instability.