Unsatisfactory radiographic findings do not correlate with functional impairment in patients with coronal shear fractures of the distal humerus treated with internal fixation: a long-term retrospective study according to Dubberley's classification.

Aim of the study: Coronal shear fractures of the distal humerus are uncommon elbow fractures involving the capitellum and trochlea. Dubberley's classification is the most commonly used, and open reduction with internal fixation is the standard of care. This study aims to evaluate the long-term functional and radiographic findings of coronal articular shear fractures of the distal humerus treated with internal fixation and to determine the incidence of clinical complications according to Dubberley´s classification and to correlate radiographic and functional outcomes.

Materials and methods: A surgical database of the Upper Limb Unit at our institution was retrospectively reviewed to select patients with fractures of the capitellum and trochlea treated with internal fixation. Clinical assessment at the last visit included bilateral evaluation of the range of motion, pain, and stability, Visual Analogic Scale (VAS) for pain and satisfaction, Mayo Elbow Performance Score (MEPS), Oxford Elbow Score, and Disabilities of the Arm Shoulder and Hand (DASH) questionnaire. Simple radiographs were performed at the last visit. All complications reflected in the medical record and the need for reintervention were specifically searched and collected.

Results: Thirty-two patients (23 females) with a mean age of 62.1 years and a median follow-up of 68.5 months were retrospectively reviewed. Fifteen were classified as Dubberley type 1 (46.9%), 9 as type 2 (28.1%), and 8 as type 3 (25.0%), while 19 (59.4%) presented Dubberley type B fractures. Median flexion was 130^o, extension 30^o, flexion-extension range 100^o, pronation 90^o, and supination 90^o, VAS for pain 0, VAS for satisfaction 10, MEPS 95, Oxford 47, and DASH 4.16. Eighteen patients (56.3%) experienced at least one postoperative complication, with 12 (37.5%) requiring a revision surgery. Thirteen patients (40.6%) had at least one unsatisfactory radiographic finding (most frequently a condylar osteonecrosis) but no differences were found in the functional outcomes compared to patients who did not present them, except for the loss of 10 degrees of flexion (p=0.037). Patients with type B fractures had lower flexion (7.5^o, p=0.045) and extension (10^o, p=0.033) and a higher proportion of unsatisfactory radiographic findings (8.3% type A vs. 82.4% type B, p=0.00), with no differences in the other variables analyzed CONCLUSIONS: Our study confirms the utility of the Dubberley classification in describing the fracture and selecting the surgical approach. Despite a high proportion of unsatisfactory radiographic findings, they were well tolerated with no correlation with functional impairment.

Level of evidence: Level IV; Case Series; Treatment Study.