High rate of failure after magnesium bioabsorbable compression screw fixation for scaphoid fractures.

Abstract

Purpose: This retrospective study aimed to evaluate the clinical and radiological outcomes of magnesium (Mg) bioabsorbable compression screws in the management of scaphoid fractures and nonunion. Despite theoretical benefits, such as osteoinductive properties and gradual degradation facilitating bone remodeling of these novel implants, clinical evidence on their efficacy remains limited.

Materials and methods: A retrospective analysis was conducted on 20 patients who underwent scaphoid fracture or nonunion surgery with Mg screws at our hospital between 2015 and 2024. Patients with a minimum of 12 months of radiological follow-up were included. Functional assessments were conducted using the Quick Disabilities of the Arm, Shoulder, and Hand (Q-DASH) and Mayo Wrist Score, while radiographic outcomes focused on union, screw integrity, and cystic changes. Statistical analysis compared grip strength and wrist range of motion to the contralateral side.

Results: The mean clinical follow-up period was 78.3 months (SD ± 22.0; range 14-108), and the mean radiological follow-up was 59.1 months (SD ± 30.5; range 12-99). Functional assessments showed a mean Q-DASH score of 11.5 (SD ± 16.9; range 0-68.2) and a Mayo Wrist Score of 75.7 (SD ± 13.3; range 45-95), indicating moderate functional recovery. The non-union rate was 40%, with complications including screw breakage in 25% of patients and cystic lesion formation around screws in most cases. No infections were reported. Wrist range of motion and grip strength were both significantly reduced on the injured side compared to the intact side.

Conclusions: Mg screws demonstrate potential benefits for bioabsorbable fixation, but our findings indicate a high rate of complications, including non-union and screw instability, in scaphoid fractures. The study suggests that Mg screws may not provide adequate stability for complex fractures in small bones like the scaphoid.

Level of evidence: Level IV, retrospective cohort study.