Consistency of long-term outcome of acute Rockwood grade III acromioclavicular joint separations after K-wire transfixation

BACKGROUND: Surgical approach to acute Rockwood grade III acromioclavicular (AC) joint injuries demands satisfying and reliable treatment results of shoulder function in the long term. This study investigates the operative outcome of acute grade III AC joint separations after temporary K-wire transfixation of the AC joint over the years. We hypothesize, that the well-established temporary articular transfixation of acute Rockwood grade III AC joint dislocations with K-wires provides good and consistent functional outcome at long term. METHODS: Seventy patients who underwent temporary articular transfixation of the AC joint followed by a standardized rehabilitation program and early physiotherapeutic exercising were divided into three follow-up cohorts. The treatment results were investigated 1 to 2 years (short-term, group A, n = 18), 3 to 5 years (mid-term, group B, n = 33), and 6 to 10 years (long-term, group C, n = 19) after surgical procedure. The outcome was measured using a standardized functional patient questionnaire including Constant score, ASES rating scale, SPADI, and XSMFA-D score. The results given in average and mean ± SD were compared between the three cohorts by calculating the Kruskal-Wallis one way analysis for variance on ranks. RESULTS: Average patient age at time of surgical therapy was 37 (±11) years without significant difference between the three cohorts. Independent of follow-up period all patients demonstrated good functional treatment results in the long run expressed by an over all Constant score of 88 (±10) points, ASES rating scale of 29 (±3) points, SPADI of 3 (±9) points, XSMFA-D function score of 13 (±2) points, and XSMFA-D impairment score of 4 (±1) points, respectively. The comparison of the three follow-up groups proved no significant differences in outcome over a maximum follow-up period of up to 10 years. However, the longer the follow-up period, the tendency of the promising treatment outcome becomes more stable. CONCLUSIONS: Temporary K-wires fixation of acute Rockwood grade III AC joint separations enable good long-term results in shoulder function. The achieved functional outcome parameters reveal a high consistency in the long run over the years.