Risk factors that influence subsequent recurrent instability in terrible triad injury of the elbow.

Objective: To identify risk factors associated with subsequent recurrent instability and to identify predictors of poor outcomes in terrible triad injury of the elbow. Design: Retrospective cohort study. Setting: University trauma center. Patients/Participants: Seventy-six patients who were surgically treated for terrible triad injury of the elbow. Intervention: Review of charts and standardized x-ray images before surgery and 2 years after surgery. Patients were categorized into 2 groups: recurrent instability (group A) or concentric stability (group B). Main Outcome Measurement: Primary outcome measures were injury mechanism, time between injury and operation, fracture type, ligament injury, radial head fixation, coronoid fixation, ligament repair, period of postoperative immobilization, joint space restoration, healing progress, secondary operation, functional outcomes, and complications. Secondary outcome measures were age, sex, height, body mass index, bone mineral density, and comorbidities (hypertension and diabetes). Outcomes were measured before surgery and 2 years after surgery and were compared between groups. Results: Recurrent instability occurred in 19.7% of cases; revision surgeries were performed in 12 cases (80%). High-energy trauma (P = 0.012), time between injury and operation (P = 0.001), radial head comminution (P = 0.001), medial collateral injury (P = 0.041), and coronoid nonrepair (P = 0.030) were associated with recurrent instability. Posttraumatic arthritis developed more often in group A (P = 0.001). Conclusions: Recurrent instability was associated with highenergy trauma, time between injury and operation, Mason type III radial head fracture, medial collateral injury, and coronoid nonrepair. Patients with recurrent instability were more likely to require secondary surgery and develop posttraumatic arthritis than those with concentric stability.