Vol.:(0123456789) 1 3 Archives of Orthopaedic and Trauma Surgery https://doi.org/10.1007/s00402-018-3075-x TRAUMA SURGERY Which lateral clavicle fractures can be treated by an arthroscopic- assisted endobutton procedure? An analysis of risk factors Emanuel Kuner 1  · Frank J. P. Beeres 2  · Reto Babst 2  · Ralf Schoeniger 2 Received: 16 July 2018 © Springer-Verlag GmbH Germany, part of Springer Nature 2018 Abstract Introduction Arthroscopy-assisted treatment of lateral clavicle fractures with coracoclavicular stabilization and an endobut- ton 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 diference between the afected and the unafected 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 func- tional 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. Keywords Lateral · Clavicle · Fracture · Arthroscopic · Nonunion · Risk factors Introduction Clavicle fractures account for 2–5% of all fractures in adults [1]. Approximately 12–25% involve the lateral clavicle [1]. The mechanism of accident usually involves direct impact on the shoulder [2]. Neer’s classifcation is commonly used to classify lateral clavicle fractures [3]. In this classifcation, one can diferentiate between stable and unstable fractures [3, 4]. In the case of stable Neer type I and III fractures, nonoperative therapy is recommended [5, 6]. Neer type II fractures are characterized by disruption of the coracoclav- icular ligaments from the medial clavicular shaft [3]. There is no consensus on what the best treatment is for unstable lateral clavicle fractures (Neer type II). High nonunion rates between 22–40% have been described with nonoperative treatment [2, 7, 8], although up to 80% of these are asymp- tomatic [7]. Emanuel Kuner and Frank J. P. Beeres were co-frst authors. * Emanuel Kuner emanuel.kuner@luks.ch Frank J. P. Beeres frank.beeres@luks.ch Reto Babst reto.babst@luks.ch Ralf Schoeniger ralf.schoeniger@luks.ch 1 Luzerner Kantonsspital, Spitalstr. 50, 6110 Wolhusen, Switzerland 2 Luzerner Kantonsspital, Spitalstrasse 16, 6000 Lucerne, Switzerland