Capitellar cartilage injuries concomitant with radial head fractures.

PURPOSE: To evaluate the incidence and types of capitellar cartilage injuries associated with higher-grade radial head fractures.

METHODS: Fifty-one consecutive patients with operatively treated, unstable, displaced Mason type II to III radial head fractures were identified. Ten of 51 patients had capitellar cartilage injuries concomitant with these fractures. All cartilage injuries were identified at the time of surgery except in 1 patient whose injury was determined via computed tomography. There were 8 men and 2 women with an average age of 33 years (range, 24-39 years). Lesions were seen with direct inspection and recorded by location, size, and thickness.

RESULTS: The incidence of capitellar chondral lesions concomitant with operatively treated Mason type II to III radial head fractures appeared in 10 of 51 patients. The average size was 5 x 5 mm (range, 2 x 2 mm to 10 x 10 mm). Four patients had Mason type II and 6 had Mason type III radial head fractures. The average surface of the cartilage injury was 6 x 7 mm (range, 3 x 6 mm to 10 x 10 mm) for Mason type II fractures and 4 x 4 mm (range, 2 x 2 mm to 5 x 10 mm) for Mason type III fractures. Two Mason type III fractures had full-thickness cartilage lesions, and 4 Mason type III fractures had partial-thickness cartilage lesions. Two Mason type II fractures had full-thickness cartilage lesions and the other 2 had partial-thickness cartilage lesions.

CONCLUSIONS: Capitellar cartilage lesions frequently occurred concomitantly with higher-grade radial head fractures. The incidence of these lesions increased with greater severity of radial head fractures. Low-grade radial head fractures created higher-grade cartilage lesions as the intact radial head can cause more damage to the capitellum. Careful evaluation of the joint should be performed for these subtle injuries.

TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.