New light on old shoulders: palaeopathological patterns of arthropathy and enthesopathy in the shoulder complex.

Rotator cuff disease represents the most common cause of modern shoulder pain and disability. Much of the clinical literature on rotator cuff disease focuses on subacromial impingement and supraspinatus tendinopathy, although other patterns of lesions are also recognised. Rotator cuff disease has received relatively little attention in palaeopathological literature, but signs relating to subacromial impingement have been reported. Given the variety and patterns of lesions that are recognized clinically as rotator cuff disease, this study aimed to investigate whether a similarly wide range of lesions could be identified in human skeletal remains. Degenerative changes in surfaces around the shoulder were recorded in a sample of 86 skeletons. The resultant data were assessed using both simple descriptive statistics and exploratory factor analysis. Degenerative changes characteristic of modern subacromial impingement formed a minor underlying pattern in the data. The predominant underlying variable in the data represented an association between lesser tuberosity, bicipital sulcus and glenohumeral degenerative changes. This pattern reflects recent reports in the clinical literature highlighting the prevalence of subscapularis tendinopathy, and also supports a pathoaetiological model of progression from subscapularis to long head of biceps to glenohumeral involvement. The degenerative changes seen at the non-articular, fibrocartilaginous entheses on the humeral tuberosities were similar to those seen in subchondral bone in osteoarthritis.