Surgical treatment and outcomes of trans-ulnar basal coronoid fracture-dislocations.

Background: Trans-ulnar fracture-dislocations of the elbow are complex injuries that can be difficult to classify and treat. Trans-ulnar basal coronoid injuries, in which the coronoid is not attached to either the olecranon or the metaphysis, present substantial challenges to achieve anatomic reduction and stable internal fixation. The purpose of this study was to analyze the outcome of surgical treatment of trans-ulnar basal coronoid fracture-dislocations.

Materials And Methods: Between 2002 and 2019, 32 consecutive trans-ulnar basal coronoid fracture-dislocations underwent open reduction and internal fixation at our institution. Four elbows were lost to follow-up within the first 6 months after surgery and were excluded. Among the 28 elbows remaining, there were 13 females and 15 males with a mean age of 56 (range 28-78) years at the time of injury. The mean clinical and radiographic follow-up times were 37 months and 29 months, respectively. Radiographs were reviewed to determine rates of union, Hastings and Graham heterotopic ossification (HO) grade, and Broberg and Morrey arthritis grade.

Results: Union occurred in 25 elbows. Union could not be determined for 1 elbow at most recent follow-up and the remaining 2 elbows developed nonunion of the coronoid. Complications occurred in 10 elbows (36%): deep infection (4), ulnar neuropathy (2), elbow contracture (2), and nonunion (2). There were reoperations in 11 elbows (39%): irrigation and débridement with hardware removal (4), hardware removal (2), ulnar nerve transposition (2), contracture release with HO removal (2), and revision with iliac crest autograft (1). At most recent follow-up, the mean flexion-extension arc was 106° (range 10°-150°), and the mean pronation-supination arc was 137° (range 0°-170°). The mean Quick Disabilities of Arm, Shoulder, and Hand score was 11 (range 0-39) points with a mean Single Assessment Numeric Evaluation-Elbow score of 81 (range 55-100) points. At final radiographic follow-up, 16 elbows (57%) had HO (8 class I and 8 class II), and 20 elbows (71%) had arthritis (8 grade 1, 6 grade 2, and 6 grade 3).

Discussion: Trans-ulnar basal coronoid fracture-dislocations are severe injuries associated with high rates of reoperation, HO, and post-traumatic arthritis. However, the majority of elbows achieve union, a functional range of motion, and reasonable patient reported outcome measures. Over the study period, surgeons were more likely to utilize multiple deep approaches and separate fixation of the coronoid (either with lag screws or anteromedial plates) to ensure anatomic reduction.