Retrospective Analysis of 3D Printing-Assisted Surgical Outcomes in Chronic Coronal Shear Fractures of the Humeral Trochlea and Capitellum.

Objectives: Chronic capitellum-trochlea coronal shear fractures (defined as untreated injuries > 3 weeks) are complex intraarticular fractures of the distal humerus, primarily caused by missed diagnoses of low-energy trauma and typically requiring open reduction and internal fixation (ORIF). These articular fractures are associated with high complication rates, including nonunion and post-traumatic osteoarthritis. This retrospective analysis of ten patients evaluated the clinical efficacy of 3D printing-assisted ORIF in improving surgical precision and functional outcomes (assessed by Mayo Elbow Performance Score, MEPS) for chronic coronal shear fractures involving the humeral trochlea and capitellum. Methods: This retrospective study included ten patients with chronic coronal shear fractures treated with open reduction and internal fixation between September 2017 and September 2022. 3D-printed anatomical models were generated from CT scans using Medraw software to design patient-specific surgical strategies. Postoperative outcomes were assessed using the Mayo Elbow Performance Score (MEPS) by a blinded evaluator. Results: Patients ranged in age from 13 to 67 years (40.8 ± 17.2 years). All patients with closed fractures underwent surgery 5-16 weeks after injury (9.3 ± 3.6 weeks). No early postoperative complications, such as wound healing issues, were observed. Follow-up periods ranged from 8 to 12 months (9.7 ± 1.9 months), and bony union times averaged 12.9 ± 4.1 weeks (range, 8-19 weeks). No long-term complications, including instability or fixation loosening, were reported. The mean MEPS was 92.5 ± 8.2, with excellent results in seven cases and good results in three cases. Conclusions: 3D printing may aid in developing precise, patient-specific surgical plans, potentially improving articular reduction accuracy and minimizing intraoperative challenges in treating chronic coronal shear fractures of the humeral trochlea and capitellum.