Coracoclavicular fixation techniques for Neer IIb and "extralateral" fractures of the distal clavicle: a systematic review.

Background: Unstable "extralateral" fractures of the distal clavicle (lateral to the coracoclavicular ligaments) are not distinguished in the Neer classification system and are commonly included with Neer IIb fractures. In the literature, there is no optimal surgical technique for managing unstable fractures of the distal clavicle, nonetheless for unique "extra-lateral" patterns. The aim of this study is to evaluate the effectiveness and safety of existing coracoclavicular fixation techniques for managing unstable Neer IIb and extralateral (IIc) fractures of the distal clavicle. Methods: We performed a systematic search of the literature to capture all studies evaluating the safety and effectiveness of existing coracoclavicular loop techniques for unstable Neer IIb and extralateral (IIc) fractures of the distal clavicle. We searched the PubMed (MEDLINE and PubMed Central), Scopus, Web of Science, Google Scholar, and Cochrane Central Register of Controlled Trials electronic databases to retrieve studies published between January 2000 and November 2020. Our study was guided by a prospectively developed protocol and reported in accordance with the latest Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Results: Our database search yielded a total of 564 records; of which, 21 were deemed appropriate for inclusion in our qualitative synthesis. The total number of reported IIb/c fractures managed with a coracoclavicular stabilization technique in all studies was 421. In total, 139 (33%) patients received arthroscopic-assisted treatment, and 282 (67%) patients were managed with open coracoclavicular stabilization. The reported clinical results were very good to excellent in most studies, whereas the overall major and minor complication rate was 2.6% and 12.8%, respectively. Major complications were more frequent in arthroscopic-assisted techniques (4.3%) compared with open (1.8%). Conclusion: The present systematic review of coracoclavicular stabilization techniques for unstable Neer IIb and extralateral fractures of the distal clavicle demonstrates promising clinical outcomes, including effectiveness and safety. We support the previously proposed modification of the Neer classification to include this unique type of unstable extralateral fracture (type IIc) to allow for targeted surgical management.