Surgery improves the clinical and radiological outcome in Rockwood type IV dislocations, whereas Rockwood type III dislocations benefit from conservative treatment.

purposeDespite the available classifications, diagnostics and treatment of acute acromioclavicular joint (ACJ) injuries are still vague and challenging for trauma and shoulder surgeons. This study aimed to evaluate the dynamic radiographic as well as clinical outcome of operatively and conservatively treated Rockwood (RW) type III and IV ACJ dislocations. MATERIALS AND

methodsAll patients with RW type III and IV ACJ dislocations between 2009 and 2016 (n = 226) were included in this retrospective data analysis with a prospective follow-up examination. According to their injury classification, patients were subdivided in an operative and conservative treatment group. Examiner blinded clinical evaluation including the constant score (CS), American shoulder and elbow surgery (ASES) score, the acromioclavicular joint instability (ACJI) score, visual analog scale (VAS), bilateral force measurements, and posttraumatic/postsurgical sequelae were assessed. Fluoroscopic evaluations including dynamic stability assessment with functional axillary views were performed for every patient.

resultsFor follow-up examination (mean 4.8 years ± 0.3 SEM) 56 patients (29 RW type III, 27 RW type IV) were available. In patients with RW type III ACJ dislocations [operative (n = 10); conservative (n = 19)] prolonged duration of treatment was seen in operatively treated patients (p < 0.05). Clear improvement could be shown for the ACJI score (p < 0.05) and coracoclavicular (CC) and acromioclavicular (AC) distance (p < 0.05) in the operative group. In patients with RW type IV ACJ dislocations [operative (n = 18); conservative (n = 9)] superior clinical results were found in operated patients with highly significant differences for the ACJI score (p < 0.001). Radiographic dynamic horizontal analysis showed nearly normalized anteroposterior translation in operated patients (p < 0.05). No differences were found regarding arthroscopic or open procedures.

conclusionAccurate diagnostics including sufficient dynamic stability assessment with functional axillary views are strongly advised for patients with ACJ dislocations. Conservative treatment should be recommended for patients with RW type III ACJ dislocations, due to shorter duration of treatment with good clinical results but lacking operative risks. In patients with RW type IV ACJ dislocations, surgical treatment is recommended because of superior clinical and radiological results. LEVEL OF EVIDENCE: Level III.