Posterolateral rotatory instability of the elbow after corrective osteotomy for previously asymptomatic cubitus varus deformity.

BACKGROUND

We identified a subset of patients who had posterolateral rotatory instability (PLRI) following corrective osteotomy for asymptomatic cubitus varus deformity. We aimed to identify risk factors for PLRI in such patients by comparing this subgroup to patients who did not demonstrate PLRI following osteotomy.

METHODS

We retrospectively reviewed the medical records and radiographs of 22 patients with cubitus varus that underwent corrective osteotomy at our institution between 2003 and 2010. All patients underwent surgery for cosmetic reasons, and no patient reported functional problems such as PLRI or ulnar nerve symptoms pre-operatively. We sought to identify differences between those that experienced an increase in PLRI after osteotomy (PLRI group) and those that did not (non-PLRI group) with regard to demographics, degree of deformity, amount of surgical correction, and final outcomes.

RESULTS

Five patients had PLRI after osteotomy, and all five subsequently underwent lateral ulnar collateral ligament reconstruction using a triceps tendon graft. No statistically significant difference was observed between the PLRI and non-PLRI groups in terms of demographics, degree of deformity, amount of surgical correction, range of motion, and final Mayo Elbow Performance Index (MEPI) and the Disabilities of Arm, Shoulder, and Hand (DASH) scores. However, the PLRI group had marginally greater medial displacement of the distal fragment.

CONCLUSIONS

This study demonstrates that PLRI can become apparent after corrective osteotomy for cubitus varus in the absence of clinical symptoms of instability preoperatively. We suggest that careful examination for PLRI should be performed after surgical correction for cubitus varus deformity, and surgeons should be prepared to proceed with simultaneous reconstruction of the lateral ligaments of the elbow.