Abstract
We often observe the lower joint space narrowing in primary shoulder osteoarthritis. However, previous studies reported stress distribution was found in center, center-posterior and posterior directions in primary shoulder osteoarthritis. CT osteoabsorptiometry(CTOAM) has been used to study the stress distribution changes of the glenoid and coracoacromial arch in various types of pathologic shoulders. There are few studies about primary shoulder osteoarthritis measured by CTOAM. The purposes of this study were to evaluate stress distribution of the glenoid cavity in primary shoulder osteoarthritis using CTOAM and to compare stress distribution pattern of primary shoulder osteoarthritis and asymptomatic shoulder. 27 shoulders in 24 patients with primary shoulder osteoarthritis and 27shoulders in 14 patients with asymptomatic shoulder were analyzed for this study. Results showed 6 patterns (Central; 33%, Anterior-posteroir; 22%, Anterior; 15%, Inferior; 11%, Diffused; 11%, Central-posterior; 7%) of stress distribution were observed in primary shoulder osteoarthritis, and 4 patterns (Anterior-posteroir; 44%, Anterior-center-posteroir; 38%, Anterior-inferior; 11%, Anterior; 7%) were observed in asymptomatic shoulders. Stress distribution at the glenoid cavity of primary shoulder osteoarthritis involved characteristic shift (Inferior, Diffused), which were compared to asymptomatic shoulder and previous reported cuff tear arthropathy. These results may show different pathologic change involved in primary shoulder osteoarthritis. We believe the results of this study will provide useful information to understand the pathogenesis of primary shoulder osteoarthritis.
