Clinical and radiological outcome following treatment of displaced lateral clavicle fractures using a locking compression plate with lateral extension: a prospective study

BACKGROUND Treatment of lateral fractures of the clavicle is challenging and has been controversially discussed for a long time due to high non-union rates in non-operative treatment and high complication rates in surgical treatment. Acromioclavicular joint instability due to the injury of the closely neighbored coraco-clavicular ligaments can result in a cranialization of the medial clavicle shaft. A recently developed implant showed a promising functional outcome in a small collective of patients. METHODS In this prospective study, 20 patients with a mean age of 40.7 ± 11.3 years with a dislocated fracture of the lateral clavicle (Jäger&Breitner I-III, Neer I-III) were enrolled. All patients were surgically treated using the locking compression plate (LCP) for the superior anterior clavicle (Synthes®). Functional outcome was recorded using the Munich Shoulder Questionnaire (MSQ) allowing for qualitative self-assessment of the Shoulder Pain and Disability Index (SPADI), of the Disability of the Arm, Shoulder and Hand (DASH) score and of the Constant Score. Acromioclavicular joint stability was evaluated using the Taft-Score. RESULTS The mean follow-up was 14.2 ± 4.0 months. The mean MSQ was 87.0 ± 7.4 points, the mean SPADI 91.1 ± 11.3 points, the mean DASH score 7.6 ± 7.3 points and the mean normative age- and sex-specific Constant Score 85.6 ± 8.0 points. The mean Taft Score resulted in 10.7 ± 1.0 points. The mean Taft Score in lateral clavicular fractures with fracture gap between the coracoclavicular ligaments in combination with a rupture of the conoid ligament (J&B II a, Neer II B; n =11) was with 10.3 ± 0.9 points significantly lower than the mean Taft Score of all other types of lateral clavicle fractures (J&B I, II b, III; n =9) which resulted in 11.3 ± 0.9 points (p<0.05). CONCLUSIONS The Synthes® LCP superior anterior clavicle plate allows for a safe stabilization and good functional outcome with high patient satisfaction in fractures of the lateral clavicle. However, in fractures type Jäger&Breitner II a, Neer II B a significant acromioclavicular joint instability was observed and additional reconstruction of the coracoclavicular ligaments should be performed. TRIAL REGISTRATION ClinicalTrials.gov NCT02256059. Registered 02 October 2014.