Treatment of Proximal Trans-ulnar Fracture-Dislocations Based on a Step-By-Step Coronoid-Centric Surgical Technique: Proposal of a Surgical Algorithm Based on Coronoid Management and Windows Approach

Introduction: Complex proximal ulna fractures that are associated with radial head dislocation or fracture-dislocation, often referred to as "Monteggia-like" or trans-ulnar fracture-dislocations, constitute a heterogeneous group that poses challenges for classification and treatment. Management often relies on surgeon expertise rather than systematic approaches, leading to poor outcomes, high complication rates, and frequent surgical revisions. We hypothesize that a systematic, coronoid-centric, step-by-step surgical technique could improve outcomes in trans-ulnar fracture-dislocations. Methods: A retrospective study was conducted on patients with trans-ulnar fracture-dislocations treated between 2017 and 2023. Exclusion criteria included patients younger than 18 years, open fractures beyond Gustilo grade 1, and follow-up shorter than 12 months. Fractures were classified using the coronoid-centric Mayo classification based on preoperative radiographs and CT scans. Two additional fracture patterns, characterized by distinct coronoid detachment features, were identified. Outcomes were evaluated through subjective elbow scores Subjective Elbow Value, Mayo Elbow Performance Score (MEPS), Oxford Elbow Score, QuickDASH, and range of motion (ROM) evaluations. Results: Among the 39 patients included, the most common fracture pattern was the trans-ulnar basal coronoid fracture-dislocation (49%). At a mean follow-up of 3.9 years (range 1-7), 90% (35/39) of the patients achieved a functional ROM. The mean MEPS was 85 (range 60-100), and the mean QuickDASH was 18 (range 0-45). The revision rate was 13% (5/39), due to coronoid nonunion (n = 1), olecranon fixation failure after a new trauma (n = 1), and elbow stiffness (n = 3). Ulnar nerve neuropathy was recorded in 2 of 39 patients. Discussion: A systematic, coronoid-centric surgical approach led to satisfactory outcomes in trans-ulnar fracture-dislocation with an acceptable rate of complication and revision rate. Recognizing the prognostic value of the coronoid may reduce complication rates.