Current options for treating elbow instability include bony and/or ligamentous fixation with orthosis or cast immobilization, transarticular cross-pinning, temporary bridge plating, and hinged or rigid external fixation. Our purpose was to evaluate the recently developed internal joint stabilizer (IJS), which acts as an internal external fixator of the elbow. Our primary end point was to assess whether use of the device results in a stable and congruent reduction of the ulnohumeral and radiocapitellar joints in patients with acute or chronic elbow instability as a result of trauma. In our series, patients with elbow instability as a result of acute or chronic trauma were treated with an IJS. This retrospective study reviewed 20 patients who underwent placement of a U.S. Food and Drug Administration (FDA)–approved IJS for elbow instability. Serial physical examinations and radiographs were performed to verify stability. Patients were instructed that, if they are dissatisfied with their postoperative motion, a secondary contracture release operation will be offered to them. Patients were asked to complete outcome-scoring questionnaires including the Disabilities of the Arm, Shoulder, and hand (DASH) and Mayo Elbow Performance (MEP) score. Complications were monitored for all patients. Twenty patients who underwent placement of an IJS for persistent elbow instability were reviewed. Patients with a flexion-extension arc of 70° or less at 12 weeks were offered a staged arthroscopic contracture release. The average MEP score improved from 12.2 ± 12.4 to 82.5 ± 14.3 and the average DASH score improved from 85.3 ± 23.0 to 37.26 ± 29.3. The average postoperative flexion-extension arc at most recent follow-up was 124.3° ± 14.9°, with a median follow-up of 17 months (8 weeks–25 months). Use of an IJS allows for early, congruent, and stable ulnohumeral and radiocapitellar range of motion in instances of persistent elbow instability. Therapeutic IV.