Anteromedial coronoid facet fractures with associated injuries have inferior outcomes to isolated fractures: a clinical outcomes comparison.

Abstract

Varus posteromedial rotatory instability typically results in an isolated anteromedial coronoid (AMC) fracture without an associated radial head fracture or elbow dislocation. However, recent series have shown concomitant radial head fractures, and elbow dislocations may be seen in association with AMC fractures in other injury patterns with an unclear effect on patient outcomes. Therefore, our objective was to compare postoperative patient outcomes in AMC fractures with and without concomitant radial head fractures or elbow dislocations. A retrospective review of patients who underwent operative fixation of AMC fractures at 2 academic medical centers from 2004 to 2022 was performed. Patients ≥18 years of age who sustained AMC fractures with or without elbow dislocations and/or radial head injuries were included. Our primary outcome was the Mayo Elbow Performance Index. Secondary outcomes were joint congruence, range of motion, complications, revision surgeries, and the incidence of heterotopic ossification (HO). A total of 61 AMC fractures met our inclusion criteria. The mean age of our cohort was 44 ± 16 years of which 66% were males. The average length of follow-up was 23 ± 34 months. Patient demographics were similar between groups. Thirty-two patients had no concomitant radial head fracture or elbow dislocation, and 29 patients had either a concomitant elbow dislocation and/or radial head fracture (14 isolated dislocations, 5 radial head fractures without apparent dislocation, and 10 radial head fractures with a dislocation). There were significantly more high-energy injury mechanisms in patients with concomitant injuries (P = .001). Coronoid subtype and fragment size did not differ between groups. The postoperative mean Mayo Elbow Performance Index score was significantly lower for patients with concomitant injuries (89 ± 10 vs. 96 ± 8, P = .006). Patients with concomitant elbow dislocation and/or radial head fracture had significantly less flexion and supination at final follow-up (P = .04), had a significantly higher incidence of HO (P = .008), and a higher grade of HO (P = .004). Significantly more patients with concomitant injuries underwent reoperations (19% vs. 0%, P = .007). Ulnar neuropathy, nonunion, and infection did not differ between groups. While the overall clinical outcomes of surgically managed AMC fractures were good, concomitant radial head fractures and/or elbow dislocations were associated with significantly worse patient-reported outcomes, greater stiffness, more reoperations, and a higher incidence and grade of HO. Larger cohorts are needed to confirm these findings.