Association of systemic bone mineral density and tibial cortical thickness with postoperative subsidence after surgical treatment of tibial plateau fractures.

INTRODUCTION: Tibial plateau fractures are common fractures above the age of 50 years old and are frequently considered osteoporosis-associated fractures. However, the association between bone mineral density (BMD) and postoperative articular subsidence remains unclear. The primary objective was to assess whether there was an association between systemic BMD or tibial cortical thickness and articular subsidence after surgical treatment of tibial plateau fractures. Secondary objectives were to evaluate preoperative fracture displacement and the prevalence of reduced BMD in this cohort according to WHO criteria.

MATERIALS AND METHODS: In this retrospective cohort study, patients treated surgically for low-energy tibial plateau fractures between 2017 and 2024 who underwent Dual-Energy X-ray Absorptiometry (DEXA) within 12 months before or after injury were included. DEXA-derived T-scores were used to assess systemic bone density and Tibial Cortical Thickness (TCT) was used as a measure of tibial cortical bone status. Fracture subsidence and preoperative displacement were measured in the coronal plane using articular depression. Multivariable linear regression analyses were performed adjusting for age, BMI and fracture comminution. The primary outcome was also adjusted for preoperative articular depression.

RESULTS: Fifty-nine patients were included in the analysis. There were 57 women and 2 men. Mean age was 63.9 years (SD ± 8.1) and mean BMI was 26.2 (SD ± 4.8). Schatzker type II was the most common fracture pattern (30/59, 50.8%), followed by Schatzker type VI (20/59, 33.9%). According to WHO criteria, 1.7% had normal bone mineral density, 49.2% had osteopenia and 49.2% had osteoporosis. There was no statistically significant association between postoperative subsidence and systemic BMD (p = 0.259) or TCT (p = 0.340). Nor was there a statistically significant association between preoperative articular depression and systemic BMD (p = 0.132) or TCT (p = 0.397).

CONCLUSIONS: In this study, no statistically significant association was identified between systemic BMD or tibial cortical thickness and postoperative articular subsidence or preoperative depression, although the limited sample size warrants cautious interpretation. Osteoporosis and osteopenia were common in this selected cohort of DEXA-assessed patients above the age of 50 years with surgically treated low-energy tibial plateau fractures.