Objective: To estimate the risk of athletes with Chiari malformations sustaining a catastrophic injury.
Design: Retrospective, descriptive cohort study.
Participants: All patients diagnosed with Chiari malformation at our institution between June 2008 and November 2011.
Assessment of risk factors: Participants were mailed a questionnaire regarding the number of seasons they participated in organized athletics. Magnetic resonance images were reviewed to describe the characteristics of respondent's Chiari malformations.
Main outcome measures: Whether or not the patient had sustained an injury resulting in death, coma, or paralysis.
Results: We had a 53% (N = 147) response rate. Respondents were of a mean age of 15 years (SD, 2 years) at the time of diagnosis. The mean length of protrusion of the cerebellar tonsils below the foramen magnum was 11.2 mm (SD, 5.7 mm). Most of the respondents had pointed cerebellar tonsils and some degree of crowding within the foramen magnum. During a total of 1627 athletic seasons played by patients with Chiari malformation, 0 respondents [95% confidence interval (CI), 0.0000-0.0023] sustained an injury resulting in death, coma, or paralysis. Likewise, during 191 collision sport athletic seasons, 0 (95% CI, 0.0000-0.0191) respondents sustained an injury resulting in death, coma, or paralysis.
Conclusions: The risk of athletes with Chiari malformations suffering catastrophic injuries during sports participation is low. This estimate of risk should be considered when making return-to-play decisions. Given the variability of anatomical consideration for patients with Chiari malformations, however, each return-to-play decision must continue to be made on a case-by-case basis, considering all of the available information.
Clinical relevance: The low risk of athletes with Chiari malformations suffering catastrophic injuries in sports should be considered when making return-to-play decisions.