Efficacy analysis of a double-Schanz screw external fixator combined with anti-rotating Kirschner wire in the treatment of proximal humerus fractures in skeletally immature patients.

Objectives: The objective of this study is to evaluate the efficacy of a double-Schanz screw external fixator combined with anti-rotating Kirschner wire in the treatment of displaced Salter-Harris type II proximal humerus fractures in skeletally immature patients.

Methods: A retrospective analysis was performed on 22 cases of displaced Salter-Harris type II proximal humerus fractures in skeletally immature patients who were treated with a double-Schanz screw external fixator combined with anti-rotating Kirschner wire. Patients included were the Neer-Horowitz (N-H) type 2, 3, and 4 of fracture. The basic information of the patients was recorded, fracture healing and shoulder range of motion were assessed at the last follow-up visit. The disabilities of the arm, hand (DASH) score and Constant-Murley score of the shoulder were performed to observe the occurrence of complications.

Results: The mean age at the time of surgery was 12.41 years, and all patients completed a median follow-up of 18.18 months. There were two cases of N-H type 2, 12 cases of N-H type 3, and eight cases of N-H type 4 among the patients. At the last follow-up, all patients were able to achieve pain-free shoulder movement. There was no significant difference in shoulder function between the injured side and the uninjured side. The DASH score mean was 2.43 (95% CI 1.44-3.52). The constant score mean was 98.55 (95% CI 97.73-99.27). All patients returned to their pre-injury daily life and physical activities, and there was no significant difference in bilateral limb length at the last follow-up (p < 0.05). The most common complication of double-Schanz screw external fixator combined with anti-rotating Kirschner wire surgery was pin tract infection, which occurred in 5 cases (22.7%). There were no complications such as deep infections, vascular and nerve damage, failure of fixation, secondary fracture displacement, non-union of fracture, osteonecrosis of the humerus, joint stiffness, rotator cuff weakness and limb deformity.

Conclusion: The double-Schanz screw external fixator combined with anti-rotating Kirschner wire is a safe and effective treatment for displaced Salter-Harris type II proximal humerus fractures in skeletally immature patients over the age of 10 years.