Postoperative dorsal step-off predicts olecranon osteotomy union: a retrospective cohort study

Purpose Olecranon osteotomy has been associated with loss of reduction, nonunion, implant failure, and migration of wires. We aim to evaluate quality of reduction of the osteotomy site as a predictor of olecranon osteotomy nonunion. Methods One hundred and twenty-five distal humerus fractures that underwent open reduction internal fixation (ORIF) were reviewed. Amount of dorsal step-off was measured from the lateral radiograph from the second postoperative visit. A receiver operating curve (ROC) analysis was used to assess the predictability of nonunion based on dorsal displacement of the olecranon osteotomy. Results Between 2014 and 2022, 36 patients underwent a chevron olecranon osteotomy (29%). Of the 36 patients, 7 (19%) failed to successfully unite at the osteotomy site. Two experienced aseptic nonunion, 2 were malreduced leading to nonunion, 2 malunited, and 1 had persistent fracture lines following poor osteotomy cut. Patients that developed nonunion had a mean dorsal displacement of 3.87 mm versus 1.15 mm ( p