Introduction: Primary operative stabilisation of Grade III injuries of the acromio-clavicular (AC) joint remains controversial, with recent literature providing support for conservative management. The aim of this research was to compare the clinical and radiological outcome of operative and non-operative treatment of this injury.

Materials and Methods: 56 patients (51 men, 5 women, aged 18 – 78 years) with an acromio-clavicular dislocation Tossy III were recruited into the study. 28 were managed surgically with a hook plate, and 28 were treated non-operatively with a sling until they were pain-free after a few days. The mean follow-up time was 23 months (8 – 31 months). At follow-up the patients were either examined clinically and radiologically or they were surveyed by phone. Clinical results were expressed in the Constant score and the subjective satisfaction of each patient was recorded.

Results: Eleven patients were lost to follow-up. Five patients were operated at their home hospital after initial treatment at our clinic, and four non-surgical patients were later treated with a modified Weaver-Dunn procedure.

Of the remaining 36 patients, 25 were examined clinically and radiologically and 11 were surveyed by telephone. The clinical outcome showed a mean Constant score of 87 in the operative group and 96 in the non-operative group. 30 of 36 patients were highly satisfied or satisfied (19 in the operative group, 11 in the non-operative group), 5 were mostly satisfied (operative group), 1 was unsatisfied (operative group). Radiologically, all of the operated patients showed changes of the AC-joint including widening of the joint, redislocation of the distal clavicle, and degenerative changes. In the non-operative group, three patients showed a decreasing clavicular elevation.

Conclusion: Clinical outcomes were comparable between operative and non-operative treatment of AC-dislocations grade III. Some conservatively treated patients did, however, require a secondary stabilisation. The hook plate was observed to cause additional local injury to the AC-joint, and must be removed after recovery to prevent rotator cuff damage. This procedure incurs high risk of loss of reduction. In our opinion, it is disputable to operate twice on the AC-joint to achieve similar results as those obtained with conservative treatment. We prefer a secondary anatomical reconstruction in cases of failed conservative treatment.