Functional outcomes and complications of intramedullary fixation devices for Midshaft clavicle fractures: A systematic review and meta-analysis

Background: An alternative to the current gold standard in operative treatment of displaced midshaft clavicle fractures (DMCF) using plate osteosynthesis, is internal fixation by means of intramedullary fixation devices. These devices differ considerably in their specifications and characteristics and an evaluation of their clinical results is warranted. The aim of this systematic review is to generate an overview of functional outcomes and complications in the management of DMCF per available intramedullary device. Methods: A systematic review was conducted to identify all papers reporting functional outcomes, union rates and/or complications using an intramedullary fixation device for the management of midshaft clavicle fractures. Multiple databases and trial registries were searched from inception until February 2020. Meta-analysis was conducted based on functional outcomes and type of complication per type of intramedullary fixation device. Pooled estimates of functional outcomes scores and incidence of complications were calculated using a random effects model. Risk of bias and quality was assessed using the Cochrane risk of bias and ROBINS-I tools. The confidence in estimates were rated and described according to the recommendations of the GRADE working group. Results: Sixty-seven studies were included in this systematic review. The majority of studies report on the use of Titanium Elastic Nails (TEN). At 12 months follow up the Titanium Elastic Nail and Sonoma CRx report an average Constant-Murley score of 94.4 (95%CI 93-95) and 94.0 (95%CI 92-95) respectively (GRADE High). The most common reported complications after intramedullary fixation are implant-related and implant-specific. For the TEN, hardware irritation and protrusion, telescoping or migration, with a reported pooled incidence 20% (95%CI 14-26) and 12% (95%CI 8-18), are most common (GRADE Moderate). For the Rockwood/Hagie Pin, hardware irritation is identified as the most common complication with 22% (95%CI 13-35) (GRADE Low). The most common complication for the Sonoma CRx was cosmetic dissatisfaction in 6% (95%CI 2-17) of cases (GRADE Very low). Conclusion: Although most studies were of low quality, good functional results and union rates irrespective of the type of device are found. However, there are clear device-related and device-specific complications for each. The results of this systematic review and meta-analysis can help guide surgeons in choosing the appropriate operative strategy, implant and informing their patient.