Biodegradable pins for lateral condylar fracture of the humerus with an early delayed presentation in children: a retrospective study of biodegradable pin vs. Kirschner wire

BACKGROUND: The clinical outcome of open reduction and internal fixation (ORIF) for delayed lateral condylar fracture of the humerus (LCFH) varies in different studies, but ORIF for LCFH with an early-delayed presentation usually resulted in significant improvement of elbow function. Early delayed presentation is defined as a period of 3 to 12 weeks from the injury. This study aims to compare the clinical outcomes of biodegradable pin (BP) vs. Kirschner wire (KW) in the treatment of LCFH with an early delayed presentation. METHODS: LCFH with an early-delayed presentation treated with KW or BP were retrospectively reviewed in our hospital. The patients were divided into two groups KW (n = 17) and BP group (n = 26). Baseline information, including sex, age, operative side, duration from injury to surgery, and implant choice, was reviewed. Radiographs and medical records were collected from the Hospital Database. RESULTS: In all, 17 patients (male/female, 9/8) in KW and 26 patients (male/female,13/13) in the BP group were included. The age showed no statistically significant difference between the KW (52.3 ± 10.2, month) and the BP (56.1 ± 10.7, month), (P = 0.258). At the last follow-up, there existed no statistically significant difference between the two groups concerning Baumann’s angle (P = 0.272) and carrying angle (P = 0.911). The MEPS at the last follow-up was better in the KW group (91.1 ± 2.7) than the BP group (89.2 ± 3.0), (P = 0.048). There was no case of nonunion or malunion in both groups. The incidence of fishtail deformity was (8/17, 47.1%) in KW and (13/26, 50%) in the BP group. The incidence of lateral prominence was (5/17, 29.4%) in the KW and (7/26, 26.9%) in the BP group. Furthermore, the incidence of implant prominence was higher in KW (12/17, 70.6%) than BP (0) (P < 0.001). CONCLUSION: Open reduction and internal fixation for LCFH with an early-delayed presentation produced satisfactory outcomes. Biodegradable pin is a good alternative to Kirschner wire, with comparable clinical outcomes.