Does Screw Size or Configuration Affect Hardware Removal Rate in Surgically Treated Tibial Tubercle Fracture.

Background: Displaced tibial tubercle fractures in adolescent patients typically require surgical management. There is limited research on the relationship between fracture type, screw construct, and clinical outcomes. Symptomatic screws and the need for screw removal are suggested to be associated with larger screw size. The purpose of this study is to investigate the impact of screw size and fixation construct on treatment outcomes and the risk of symptomatic hardware.

Methods: Tibial tubercle fractures treated at a level I pediatric trauma center from January 2010 to December 2022 were retrospectively reviewed. Three groups were defined based on the largest screw size used for fixation (small: <5.0, medium: 5.0 to 6.0, large: >6.0 mm). Bivariate statistics were used to evaluate associations between screw size, patient demographics, and fracture treatment. The primary outcomes studied were rates of postoperative symptomatic hardware, symptomatic hardware removal, and fracture displacement. Univariate and multivariate logistic regression analyses were used to identify independent predictors of symptomatic hardware and symptomatic hardware removal.

Results: One hundred eighty-two knees in 168 patients were included. The mean age was 14.5 years (SD: 1.4 y), 94.5% male. Screw size distribution was small in 26 knees (14.3%), medium in 83 (45.6), and large in 73 (40.1%). Screw size was significantly different among the Ogden types (P<0.001). Forty-one patients (22.5%) had symptomatic hardware, and 31 (17%) underwent removal of hardware at a median of 11 months postoperative. Rates of symptomatic hardware were not statistically different in the screw size groups (P=0.184). Screw size, number, and washer use were not associated with risk of symptomatic hardware or removal in multivariate analysis.

Conclusion: Symptomatic hardware following operatively treated tibial tubercle fractures is common, occurring in ∼1 out of 5 patients. Fracture type, screw size and number, and fixation construct were not associated with increased risk of symptomatic hardware. Surgeons should counsel patients on the potential for symptomatic hardware and secondary removal procedures, but this should not limit their choice of fixation construct.

Level of evidence: Level III-retrospective, therapeutic study.