Uncovered posterolateral rotatory elbow instability with cubitus varus deformity correction

The relationship between a longstanding cubitus varus deformity and the delayed onset of posterolateral rotatory instability has casually been reported as being caused by abnormal repetitive varus and external rotation torques with progressive failure of the lateral collateral ligament. This article presents a case of longstanding cubitus varus in a young man, following a supracondylar fracture sustained during childhood. Posterolateral rotatory instability with lateral collateral ligament deficiency was discovered after a corrective distal humeral realignment osteotomy. The scenario was worsened by medial olecranon overgrowth that predicated symptomatic medial snapping triceps during terminal extension and secondary ulnar neuropathy. Lateral collateral ligament reconstruction as well as an extra-articular olecranon osteotomy was performed. The ligament was reconstructed with a free graft harvested from the central portion of the distal triceps and secured with 2 bioabsorbable screws. The patient returned to work with no residual symptoms at final follow-up. This case highlights the possibility of posterolateral rotatory instability even with no clinical evidence at presentation. It suggests the importance of laterally redirecting the triceps vector and reconstructing the lateral collateral ligament as additional procedures at the time of supracondylar osteotomy.