This retrospective study was carried out to study the outcome of the modified Bosworth technique for Tossy Type III Acromioclavicular Joint (ACJ) dislocation; good or excellent results were obtained in 91% of cases.

Thirty-six patients were operated for Tossy Type III ACJ dislocations over a period of five years. Thirty-five patients were available for follow-up, one was lost to follow-up. All patients were operated upon using a modified Bosworth technique. Through a strap incision medial to the ACJ, the subperiosteal flaps of trapezius and deltoid were raised along the longitudinal axis of the clavicle. The ACJ was reduced and a partially threaded, cancellous, screw with washer was used under vision to lag clavicle to the coracoid process. The shoulder was immobilised in a collar and cuff sling for six weeks. The screw was removed at between six and eight weeks in 94% cases and the shoulder was mobilised. Patients were assessed using the modified Constant Score (muscle power assessed clinically using Medical Research Council’s grading). Thirty-one patients were operated upon acutely (with in an average of eight days), two sub acutely at four and seven weeks and two chronically at 15 and 24 months. The average follow up was 35 months (range: seven to 60 months). The average age was 35 years (range: 25– 62 years).

Using the modified Constant score: 26 patients (74%) scored 100; five patients (14%) scored 90–99 and one patient (3%) scored 87 (against a score of 96 on the other side due to gross obesity). Three patients (9%) scored poorly.

The first patient scored 49 and she needed reinsertion of the screw at two weeks as following a fall the screw loosened and backed out. She underwent a coracoacromial ligament transfer and another lag screw at 12 months. The second patient scored 59; however, this patient was on oxygen therapy, corticosteroid therapy and heparin for asthma. The third patient scored 79 but also suffers from cervical spondylitis and is an intravenous drug abuser.

In our experience the modified Bosworth technique has proven to be a reliable method for treating Tossy III dislocations of the ACJ. This has applied to all ages and both acute and chronic dislocations. We conclude that this technique can produce good to excellent functional results and hence we recommend its use for Tossy Type III ACJ dislocation.