A Retrospective Comparison of Headless Versus Standard Interlocking Screw Fixation of Tibia Intramedullary Nails.

Introduction: Symptomatic interlocking screws are common after intramedullary nail fixation of tibia fractures. Low-profile headless interlocking screws recently became available and could potentially reduce the rate of symptomatic screws. The purpose of this study was to compare the rate of symptomatic screws and screw removals between these screw types.

Methods: A retrospective review identified patients with tibia shaft fractures treated with tibia intramedullary nails between August 1, 2018 to September 1, 2023 by 11 surgeons. Low-profile headless interlocking screws became available on June 28, 2021 and were routinely used thereafter. Patients treated with low-profile headless versus standard headed interlocking screws were compared in terms of symptomatic screws, defined as a patient reporting pain or discomfort at the site of a screw head in clinical documentation, symptomatic screw removals, screw failure (breakage or backout), and procedures to promote bone union.

Results: Overall, 79 patients were included in the analysis: 33 patients treated with 144 headless screws and 46 patients treated with 187 standard screws. The median patient age was 35 years, and a majority were male (68.4%, n = 54). The median follow-up length was 8.5 months (interquartile range 5.5 to 8.8 months). The headless screw group, compared with standard screw group, did not differ in age, injury mechanism severity, open fracture classification, tobacco use, American Society of Anesthesiologists classification >2, number of interlocking screws used, or follow-up time (P > 0.05). The headless screw group was less likely to have symptomatic screws (0.0% vs. 23.9%; P = 0.002), less likely to have symptomatic screw removal (0.0% vs. 13.0%; P = 0.03), and had no difference in procedures to promote bone union (10.0% vs. 6.8%; P = 0.68) or screw backout (0.0% vs. 4.4%; P = 0.50).

Discussion: Standard headed interlocking screws were symptomatic in 23.9% of patients and 13.0% underwent symptomatic screw removal. In comparison, no patients treated with low-profile headless interlocking screws had symptomatic screws.

Level of evidence: Level 3, diagnostic.