Publication:

Outcome of dynamization in delayed union of femoral shaft fracture

Background Delayed union in femoral shaft fractures presents a significant clinical challenge despite the widespread success of intramedullary nailing (IMN). Nail dynamization is a minimally invasive and cost-effective intervention that promotes healing by increasing interfragmentary motion. This study evaluates the clinical and radiological outcomes of nail dynamization in delayed union cases and identifies key prognostic factors influencing healing.

Methods This prospective observational study was conducted at the National Institute of Traumatology and Orthopedic Rehabilitation (NITOR), Bangladesh, between March 2019 and March 2024. Twenty-four patients with delayed union of femoral shaft fractures, initially treated with static interlocking IMN, underwent dynamization. Radiological and functional outcomes were assessed, and statistical analyses were performed to identify predictors of union.

Results The mean time from nailing to dynamization was 21.1±2.6 weeks, with a mean union time of 21.4±1.4 weeks. 79.17% of patients achieved union, while 20.83% progressed to nonunion. Earlier dynamization correlated significantly with higher union rates (p=0.01). Smoking was a major risk factor for nonunion (p=0.047), with 93.33% of nonunion cases occurring in smokers. FHI was a strong predictor of union (p=0.002), with higher FHI values associated with successful healing. Functional outcomes were excellent in 62.50% of patients, and 66.67% reported no pain at the final follow-up.

Conclusion Nail dynamization is a clinically effective and low-cost intervention for delayed union of femoral shaft fractures. Timely dynamization and higher FHI values significantly predict successful healing, while smoking negatively impacts outcomes. These findings highlight the need for early intervention and patient-specific treatment strategies to optimize fracture healing.