Purpose of the study: Classically, the shoulder joint is thought to age more by its tendons than by its cartilages, the incidence of rotator cuff tears being considered to increase with age. The purpose of this work was to assess the natural history of the shoulder joint based on a clinical and radiological study of 200 patients aged 70 to 101 years.
Material and methods: The cohort was composed of 48 men (34%) and 152 women (76%), aged 84.25 +/- 6.7 years. All patients underwent a physical examination and the Constant score was established. The radiographic examination included an AP view in neutral rotation of both shoulders. The Hamada classification was used to stage full thickness cuff tears. The glenohumeral compartment was analyzed to search for osteophyte formation and joint narrowing.
Results: The subacromial height was greater than 6 mm, mean 9.89 +/- 2 mm, in 349 shoulders (87.25%), corresponding to stage I in the Hamada classification; it measured less than 6 mm, mean 3.08 +/- 1.7 mm in 51 shoulders (12.75%) in 38 subjects (19% of the total cohort). The Hamada classification for the other shoulders was stage II (n = 21 shoulders, 5.25%), and stage III (n = 16 shoulders, 4%), stage IV (n = 5, 1.25%) and stage V (n = 5, 1.25%). The Hamada stage could not be determined for four shoulders. There was a strong statistical correlation between the Constant score and Hamada stage. The glenohumeral space was normal in 288 shoulders (72%). Ninety-three shoulders (23.25%) in 62 patients (31%) presented humeral and/or inferior glenoid osteophytes without glenohumeral impingement and 19 shoulders (4.75% in 14 patients (7%) presented complete glenohumeral impingement. There was a significant correlation between the Constant score and severity of the glenohumeral degradation. The proportion of subacromial impincement increased significantly and regularly with degradation of the glenohumeral space (p < 104). For half of the shoulders, glenohumeral impingement was associated with subacromial impingement (eccentric osteoarthritis).
Discussion: The results of this study confirm that the frequency of rotator cuff tears increases with age. One out of five patients aged 70-90 years presented subacromial impingement versus one out of three among patients aged over 90 years. Clinical tolerance of subacromial impingement or subacromial osteoarthritis is good. Glenohumeral impingement, associated or not with subacromial impingement, is poorly tolerated, the patients presenting shoulder pain and marked stiffness.
Conclusion: Our results demonstrate that the natural history of the shoulder does not exhibit a regular linear relationship with the Hamada radiological classification.