Treatment of posteromedial and posterolateral dislocation of the acute unstable elbow joint: a strategic approach

Abstract

The purpose of this study was to evaluate the different treatment strategies for posterolateral and posteromedial elbow dislocation. The study enrolled 21 patients with unstable simple elbow dislocation including 16 cases of posterolateral dislocation (PLDL) and 5 cases of posteromedial dislocation (PMDL). In patients with PLDL, the medial side was evaluated and repaired first, followed by the lateral side. In patients with PMDL, the lateral side was repaired first, followed by the medial side according to residual instability. Among the 16 cases of unstable PLDL, 7 of 9 presenting with complex combined tear of the ulnar collateral ligament (UCL) and flexor muscle on magnetic resonance imaging showed abnormality on valgus stress testing and UCL repair. Three of 7 cases required additional lateral collateral ligament complex (LCLC) repair. Two of 9 cases showing medial complex dual lesions had normal findings on valgus stress testing and were treated only with LCLC repair. Seven of 16 cases without medial complex dual lesion had normal findings on valgus stress testing, and only LCLC repair was performed. All 5 cases of unstable PMDL showed distraction-type LCLC injury on magnetic resonance imaging and required no additional UCL repair after LCLC repair. There were no cases of recurrent instability following this treatment algorithm. In unstable elbow dislocation, PLDL and PMDL are caused by different mechanisms following damage to different structures. Therefore, different strategies are needed to ameliorate the dislocation and instability.