We previously reported the clinical significance of lesions in subacromial bursa (SAB) in frozen shoulder. Two main symptoms of frozen shoulder are pain and limitation of range of motion. The aim of this study was to understand the affect level of lesions in subacromial bursa to these two main symptoms in frozen shoulder. The cases of less than 120° in maximum rotational angles: total angles of external and internal rotation, at 90° of abduction under general anesthesia were recognized as frozen shoulder; arthroscopic capsulotomy was added when a minimum of six months of conservative treatment was not effective. We retrospectively evaluated subacromial bursographies of 38 frozen shoulders (21 male, 17 female). Anesthetic was used during subacromial bursography; pain block effect and improvement of the shoulder motion (passive flexion and passive abduction) were evaluated in the frozen shoulder group. Non-frozen shoulder group: 95 shoulders of impingement syndrome (57 male, 38 female), was used as a control for statistical analysis. The averaged pain block effect was 59.9% in the frozen shoulder group and 79.5% in the non-frozen shoulder group. Average improvement of passive flexion angles was 14.5° in the frozen shoulder group and 7.4° in the non-frozen shoulder group. Average improvement of passive abduction angles was 22.1° in the frozen shoulder group and 6.1° in the non-frozen shoulder group. Lesions in subacromial bursa had the affect level of about 60% of shoulder pain, about 15° of flexion angles and about 22° of abduction angles in frozen shoulder.
