Abstract: Objective Besides radial head and coronoid fractures,terrible triad injury of the elbow involves a wide range of soft-tissue ruptures.The paper proposes a classification of the terrible triad injury with special reference to the status of medial collateral ligament (MCL).Methods From 2004 to 2009,seven patients with terrible triad injury were treated consecutively.There were 2 in type Ⅰ (MCL-intact) managed conservatively and 5 in type Ⅱ (MCL-ruptured) managed surgically.The operation involved lateral and medial double approaches.The fractures were screw or suture fixed.The lateral collateral ligament (LCL) was repaired by sutures through drilled holes or bone anchors.The elbow was not concentric reduced during intraoperative forearm weight test,and then the MCL was further repaired.Results All 7 patients were followed up for 1-4 years (average 2 years),with healed fracture,stable elbow and no pain movement.The average range of motion was 120 degrees in flexion-extension,100 degrees in pronation-supination.The functional outcome was excellent in 5 and good in 2 according to Mayo Elbow Performance Score.Conclusion Terrible triad injury with MCL-intact was related with minor radial head and coronoid fractures and displacement and may be managed conservatively,while with MCL-ruptured,relevant to major fractures and displacement,and should be treated surgically.Further MCL repair enhances the stability greatly in terrible triad of the elbow.

Key words: Terrible triad injury, Elbow dislocation, Medial collateral ligament