Abstract
BACKGROUND: The purpose of this study was to examine factors that were associated with a decline in functional ambulatory status following fractures of the tibial diaphysis. METHODS: A retrospective review of an IRB-approved tibial diaphysis fracture database from 2012 to 2024 was conducted. Inclusion criteria were age ≥18, isolated OTA 42A-C tibia fracture treated with an intramedullary nail, and minimum 12 months follow-up. Demographics, injury, and surgical information were collected. Functional ambulatory status was measured at routine follow up intervals by the Functional Ambulatory Category (FAC) score, a six-point scale where zero represents non-ambulation and five represents normal ambulatory ability. Univariate analysis was performed using Student's T-tests and Chi-squared tests. A backwards stepwise multivariate logistic regression analysis was performed to determine factors that were independently associated with a decline in FAC score (SPSS version 29, Armonk, NY). RESULTS: 289 patients, with a mean follow up time of 15.04 ± 6.18 months, were included in the analysis with a mean age of 43.24 ± 16.22 years, body mass index of 27.19 ± 6.30, and age-unadjusted Charlson Comorbidity Index of 0.18 ± 0.54. 39.1 % of patients were female, 28.0 % patients sustained open fractures, and 52.6 % sustained high energy injuries. The logistic regression demonstrated that older age (OR = 1.04 p < .001), higher BMI (OR = 1.06 p = .024), high-energy mechanism (OR = 3.18 p = .003), nonunion (OR = 3.66, p = .005), and concomitant lower extremity fractures (OR = 4.47 p = 002), were risk factors for a decrease in final FAC score. The AUROC of the logistic regression equation was 0.787 indicating a moderate ability to discriminate between patients that will experience a loss in functional ambulatory ability and those who will not. CONCLUSION: This study suggests that concomitant lower extremity injuries, increased age, increased BMI, high-energy mechanisms, and nonunion are risk factors that are associated with a decline in ambulatory capacity following diaphyseal tibia fractures.