External fixation and centralization versus external fixation and ulnar osteotomy: the treatment of radial dysplasia using the resolved total angle of deformity.

BACKGROUND

The purpose of this study is to compare preliminary external fixation and centralization to ulnar osteotomy with external fixation for the treatment of radial dysplasia as measured by the resolved total angle (RTA) of deformity.

METHODS

This is a retrospective review of 11 patients (14 limbs) with radial dysplasia. The 3-dimensional deformity was measured by the RTA. Six patients (8 limbs, group 1) underwent correction of their angular deformity with preliminary external fixator distraction followed by centralization. Five patients (6 limbs, group 2) underwent ulnar osteotomy with external fixation. Mean age was 9 years, with a mean follow-up of 41 months.

RESULTS

Initial RTA was 112 degrees for group 1, which improved to 38 degrees postoperatively, but worsened to 71 degrees at follow-up. In group 2 the initial RTA was 88 degrees, which improved to 50 degrees, with a worsening to 95 degrees at follow-up. The RTA was found to have high interrater and intrarater reliability.

CONCLUSIONS

The RTA defines the maximum deformity in radial dysplasia and is a reliable measure. Using the RTA, we showed that preliminary external fixation and centralization are more effective than ulnar osteotomy with external fixation, but both have a high recurrence rate.

LEVEL OF EVIDENCE: III.