Radial head fractures: loss of cortical contact is associated with concomitant fracture or dislocation.

HYPOTHESIS: Among radial head fractures displaced greater than 2 mm (Broberg and Morrey modified Mason type 2), separation (complete loss of cortical contact) of at least 1 radial head fracture fragment is associated with a complex injury pattern, meaning that there are other concomitant elbow fractures or ligament injuries.

MATERIALS AND METHODS: We identified 291 consecutive skeletally mature patients with 296 radial head fractures treated during a 6-year period. Of these, 121 consecutive fractures of part of the radial head displaced greater than 2 mm (type 2) were classified according to whether there was complete lack of cortical contact between a fracture fragment and the rest of the proximal radius. Predictors of isolated vs complex injury pattern were sought in bivariate and multivariable analyses.

RESULTS: Of 121 fractures, 30 (25%) were classified as having cortical contact, and 91 (75%) were classified as not having cortical contact. Ten (33%) with cortical contact were part of a complex elbow injury, and 83 of 91 fractures (91%) without cortical contact were part of a complex elbow injury (P < .01). Among the Mason type 2 fractures, loss of cortical contact was a significant predictor of a complex elbow injury in both bivariate and multivariable analyses, with an odds ratio of 21 (95% confidence interval, 7-59).

CONCLUSIONS: Among Mason type 2 fractures, complete loss of cortical contact of at least one fracture fragment is strongly predictive of a complex injury pattern.

LEVEL OF EVIDENCE: 4, Retrospective case series, Treatment study.