Abstract
BACKGROUND: This study aimed to compare union rates of tibia shaft fractures in two age groups: patients younger than 65 and those 65 or older. Secondary aims included comparing quality measures and functional outcomes. METHODS: A retrospective review at a single multi-site urban academic institution was conducted. Inclusion criteria included: age ≥18, isolated OTA 42A to 42C tibia shaft fracture treated with an intramedullary nail, and follow-up ≥6 months. The primary outcome was fracture union, defined as RUST score >7. Functional outcome was measured by the Functional Ambulatory Category (FAC) score (0 = nonfunctional, 5 = independent ambulation). Patients were grouped as young (<65) or elderly (≥65). Univariate and multivariate analyses controlled for confounders. RESULTS: Of 286 patients, 253 were young (mean age 38.9 ± 12.9 years) and 33 elderly (mean age 71.2 ± 6.4 years). Mean follow-up was 13.6 ± 7.9 months. Union rates (94.0% elderly vs. 89.3% young, p = 0.409) and time to union (6.4 vs. 6.1 months, p = 0.647) did not differ. Readmission (18.2% vs. 8.3%, p = 0.069) and complication rates (21.2% vs. 19.0%, p = 0.759) were also similar. After adjusting for baseline FAC, sex, BMI, CCI, fracture type, and injury mechanism, older age was associated with lower FAC scores at three (B = -0.460, 95% CI [-0.826, -0.094], p = 0.014), six (B = -0.371, 95% CI [-0.679, -0.063], p = 0.019), and twelve months (B = -0.317, 95% CI [-0.552, -0.082], p = 0.009). CONCLUSIONS: Elderly patients with tibia shaft fractures treated with intramedullary nails achieve similar union rates and healing times as younger patients. However, older age independently predicts reduced ambulatory function post-injury.