Injuries in Mixed Martial Arts After Adoption of the Unified Rules of MMA: A Systematic Review.

Background: The existing literature on injuries in mixed martial arts (MMA) is sparse and lacks a summarized review of injuries in the sport after the adoption of the new rule set in 2009. Purpose: To assess the injury characteristics in terms of injury rates and types in MMA after the adoption of the Unified Rules of MMA (URM) by the Association of Boxing Commissions and compare them with preadoption trends. Study Design: Systematic review; Level of evidence, 4. Methods: Under PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, primary literature in English examining injuries in MMA after URM adoption was scanned in Medline, Embase, and PubMed from the inception of these databases until December 27, 2023. Reports providing relevant information on injury rates and characteristics, with data solely on MMA athletes rather than in a combination of athletes from other combat sports, were reviewed and analyzed. In total, 191 reports were identified after the initial search. Descriptive statistics were employed to summarize injury rates, types, and locations, as well as variations across subgroups. Results: A total of 43 reports were included in the analysis. The reports varied widely in design, injury definitions, and data collection methods. Post-URM competition injury rates ranged from 23.6 to 54.5 injuries per 100 athlete-exposures (AEs), with soft tissue injuries (lacerations/abrasions/contusions) being the most common type of injury (20.7%-56.9% of all injuries). The most common location of injury was the head and neck area (29.5%-75.9% of all injuries). Concussion rates varied from 14.7 to 16.1 per 100 AEs, and heavier fighters experienced more knockouts and technical knockouts. There is some evidence suggesting higher injury rates among professional fighters. Conclusion: The review demonstrated that the most common injuries reported in MMA athletes are soft tissue injuries including lacerations, abrasions, and contusion mainly in the head and neck area. Professional athletes seem to have higher injury rates than amateur athletes, while heavier weight fighters sustain more knockouts and technical knockouts. Current injury rates and types seem to remain similar to those before the adoption of the URM. Analysis of current literature emphasizes a lack of standardized definitions, data on training injuries, and female injuries, which are required to fully evaluate injury characteristics in MMA and ensure the long-term well-being of those participating in the sport.