Cam-type hip morphology in asymptomatic patients

• Published in: Hip international 2024-05, Vol.34 (3), p.372-377
• Main Authors: AlMousa, Sulaiman A, Hegazi, Tarek, AlKhamis, Hashem A, AlTayyar, Ziyad A, AlMutairi, Mutlaq D, AlGhamdi, Salim A, Almuhaish, Mona I, Alzaid, Mohammed M, Alsubaie, Shayma S, Alzahrani, Mohammad M
• Format: Article
• Language: English
• ISSN: 1120-7000; 1724-6067
• DOI: 10.1177/11207000231225184

Background: The alpha angle has been widely used in the assessment of cam-type of impingement, but recent studies have shown that this angle may also be high in asymptomatic patients. The aim of this study is to report the prevalence of cam-type morphology in asymptomatic volunteers and explore its correlation with hip clinical and radiological parameters. Methods: This single-centre prospective study included 48 asymptomatic male volunteers (96 hips). All candidates fulfilled the inclusion and exclusion criteria. Physical examination and 1.5 -T MRI imaging were done for bilateral hips on the same day. Alpha angle measurements were obtained from 4 different positions and cam-type morphology was considered positive using 2 different cut points >55° and >60°. Descriptive statistics were analysed and correlations were performed where appropriate and p-value 55° was 68.8%, 87.5%, 50% and 34.4% in the 12, 1, 2 and 3 o’clock positions respectively. While it was 38.5%, 69.8%, 26% and 12.5% in the 12, 1, 2 and 3 o’clock positions of the studied hips respectively using alpha angle >60°. The maximum alpha angle was more frequently prevalent at the 1 o’clock position in 71 (74%). Labral tear was detected in 26 (27.1%) hips and impingement test was positive in 12 (12.5%) hips. There was no correlation between the presence of cam-type morphology and range of motion of the hip, presence of positive impingement test nor labral tears. Conclusions: Cam-type morphology prevalence is high among asymptomatic males, and mostly pronounced at the 1 o’clock position. A correlation between high alpha angle and positive impingement test or labral tear was not found in our cohort. Future studies are required to determine the natural history of asymptomatic cam-type morphology and risk of hip derangement.