This study prospectively evaluated the outcome of manipulation under anaesthesia and hydrodilatation as treatments for adhesive capsulitis. A total of 36 patients (38 shoulders) were randomised to receive either method, with all patients being treated in stage II of the disease process.

The mean age of the patients was 55.2 years (44 to 70) and the mean duration of symptoms was 33.7 weeks (12 to 76). Eighteen shoulders (17 patients) underwent manipulation under anaesthesia and 20 (19 patients) had hydrodilatation. There were three insulin-dependent diabetics in each group. The mean visual analogue score in the manipulation under anaesthesia group was 5.7 (3 to 8.5; n = 18) before treatment, 4.7 (0 to 8.5; n = 16) at two months (paired t-test p = 0.02), and 2.7 (0 to 9; n = 16) at six months (paired t-test, p = 0.0006). The mean score in the hydrodilatation group was 6.1 (4 to 10; n = 20) before treatment, 2.4 (0 to 8; n = 18) at two months (paired t-test, p = 0.001), and 1.7 (0 to 7; n = 18) at six months (paired t-test, p = 0.0006). The visual analogue scores in the hydrodilatation group were significantly better than in the manipulation under anaesthesia group over the six-month follow-up period (p < 0.0001).

The mean Constant score in those manipulated was 36 (26 to 66) before treatment, 58.5 (24 to 90) at two months (paired t-test, p = 0.001) and 59.5 (23 to 85) at six months (paired t-test, p = 0.0006). In the hydrodilatation group it was 28.8 (18 to 55) before treatment, 57.4 (17 to 80) at two months (paired t-test, p = 0.0004) and 65.9 (28 to 92) at six months (paired t-test, p = 0.0005). The Constant scores in the hydrodilatation group were significantly better than in the manipulated group over the six-month period of follow-up (p = 0.02).

The range of movement improved in all patients over the six months, but was not significantly different between the groups. At the final follow-up, 94% of patients (17 of 18) were satisfied or very satisfied after hydrodilatation compared with 81% (13 of 16) of those receiving a manipulation.

Most of our patients were treated successfully, but those undergoing hydrodilatation did better than those who were manipulated.

In 100 patients the fulcrum axis which is the line connecting the anterior tip of the coracoid and the posterolateral angle of the acromion, was used to position true anteroposterior radiographs of the shoulder. This method was then compared with the conventional radiological technique in a further 100 patients.

Three orthopaedic surgeons counted the number of images without overlap between the humeral head and glenoid and calculated the amount of the glenoid surface visible in each radiograph. The analysis was repeated for intraobserver reliability. The learning curves of both techniques were studied.

The amount of free visible glenoid space was significantly higher using the fulcrum-axis method (64 vs 31) and the comparable glenoid size increased significantly (8.56 vs 6.47). Thus the accuracy of the anteroposterior radiographs of the shoulder is impaired by using this technique. The intra and interobserver reliability showed a high consistency. No learning curve was observed for either technique.

We treated 22 patients with a diagnosis of primary frozen shoulder resistant to conservative treatment by manipulation under anaesthetic and arthroscopic release of the rotator interval, at a mean time from onset of 15 months (3 to 36). Biopsies were taken from this site and histological and immunocytochemical analysis was performed to identify the types of cell present. The tissue was characterised by the presence of fibroblasts, proliferating fibroblasts and chronic inflammatory cells. The infiltrate of chronic inflammatory cells was predominantly made up of mast cells, with T cells, B cells and macrophages also present.

The pathology of frozen shoulder includes a chronic inflammatory response with fibroblastic proliferation which may be immunomodulated.