Which lateral clavicle fractures can be treated by an arthroscopic-assisted endobutton procedure? An analysis of risk factors.

INTRODUCTION: Arthroscopy-assisted treatment of lateral clavicle fractures with coracoclavicular stabilization and an endobutton device have gained popularity over recent years. There is little evidence to support which types of lateral clavicle fractures are suitable for this treatment. The primary aim of this study was to evaluate the clinical und radiological outcomes of this treatment and to identify which fracture types are suitable. The secondary outcome was to evaluate potential risk factors for complications MATERIAL/METHODS: A retrospective single center review of 20 unstable lateral clavicle fractures treated with an arthroscopy-assisted CC stabilization technique and Endobutton device between September 2012 and August 2016. The functional outcome was evaluated using Constant and DASH Scores, VAS and SSV. RESULTS: Between September 2012 and August 2016, 20 patients were treated using this method (average age 45 years; male: female ratio 14:6). The DASH Score was on average 2.0 (0-9.82) and the Constant Score on average 81.8 points (range 68-93) with an average difference between the affected and the unaffected side of 4.1 points (range 0-15). Six patients had nonunion fractures of which two needed revision. CONCLUSIONS: Our study shows that arthroscopy-assisted CC stabilization using an endobutton technique delivers good functional results. Highly lateral unstable clavicle fractures seem to be especially suitable for this surgical technique. There was a high number of delayed unions. Analysis of risk factors showed that early mechanical stress, a lateral clavicular fragment larger than 3 cm and a time delay to surgery could be risk factors for nonunions.