The pathoanatomy of lateral ligamentous disruption in complex elbow instability.

We sought to determine the lateral soft-tissue injury pattern in a consecutive series of patients with elbow dislocation (10 cases) or fracture-dislocation (52 cases) that required open operative repair. Patients who were seen more than 3 months after injury or those in whom previous operative intervention had obscured the anatomy were excluded. There were 42 men and 19 women (mean age, 43 years; range, 13-82 years). One patient had bilateral injuries. The mean time to surgery was 15 days after injury, with a range from 1 to 76 days. There were associated fractures in 52 elbows: coronoid (39), radial head (36), proximal ulna (14), and distal humerus (6). Disruption of the lateral collateral ligament (LCL) complex was seen in all 62 elbows in one of six patterns of injury: proximal avulsion in 32, bony avulsion of the lateral epicondyle in 5, midsubstance rupture in 18, ulnar detachment of the LCL in 3, ulnar bony avulsion in 1, and combined patterns in 3. We found concomitant rupture of the common extensor origin in 41 cases (66%). Operative tactics included anatomic fixation of associated fractures, fixation or replacement of the radial head, and lateral soft-tissue repair. Disruption of the LCL was a universal finding in our patients. Avulsion from the distal humerus was the most common pattern, followed by midsubstance rupture; ulnar detachment or bony avulsion was rare. Disruption of the common extensor origin (a secondary constraint) was seen in 66% of cases. Repair of these lateral soft-tissue structures should be an integral part of the surgical strategy for elbow dislocations and fracture-dislocations that require operative treatment.