The Use of Sustained Dynamic Compression to Mitigate Defective Healing in Tibiotalocalcaneal Arthrodesis: A Propensity Score Matched NRD Analysis

Research Type: Level 3 - Retrospective cohort study, Case-control study, Meta-analysis of Level 3 studies Introduction/Purpose: Tibiotalocalcaneal (TTC) arthrodesis is a critical surgical intervention for managing advanced hindfoot and ankle pathologies. Achieving reliable and durable union, especially in high-risk patients, is a major challenge due to complications like nonunion. Conventional intramedullary (IM) nails provide static compression during surgery, but this compression often fails to persist postoperatively, leading to suboptimal healing. Recent advances in sustained dynamic compression (SDC) IM nails, using materials such as nickel-titanium (NiTi), offer continuous compression that adapts to changes in the bone-implant interface, potentially improving union rates. This study compares union rates between SDC and unsustained static compression (USC) IM nails using the Nationwide Readmissions Database (NRD) to evaluate the impact of compression mechanics on healing outcomes in TTC arthrodesis. Methods: This study utilized the Nationwide Readmissions Database (NRD) to compare outcomes between TTC fusion cases using SDC and USC devices. ICD-10-PCS codes were employed to identify cases involving SDC and USC nails for ankle and tarsal fusions. Propensity score matching (PSM) was used to control for potential confounders such as age, sex, and comorbidities. The primary outcomes analyzed were complications and defective healing (nonunion or malunion), and secondary outcomes included 30-day and 31-90 day readmission rates. Statistical analyses included chi-square and Fisher’s exact tests, with significance set at p < 0.05. A total of 170 patients (85 SDC, 85 USC) were included in the analysis, with demographic and clinical characteristics balanced through PSM to ensure robustness of the comparison. Results: The study found no significant difference in overall complication rates between SDC and USC groups (34.1% vs. 38.8%, p = 0.524). Specific complications, including wound dehiscence, thromboembolism, and infections, showed no statistically significant differences. However, the rate of defective healing was significantly lower in the SDC group (8.2%) compared to the USC group (20%, p = 0.022). The readmission rates were higher in the SDC group for both 30-day (5.9% vs. 1.2%) and 31-90 day (4.7% vs. 11.8%) intervals, although these differences were not statistically significant. Results are shown in Table 1. Conclusion: This study demonstrates that sustained dynamic compression (SDC) intramedullary nails lead to significantly lower rates of defective healing compared to unsustained static compression (USC) nails in TTC arthrodesis. Although no significant differences in complication or readmission rates were observed, the significantly improved union outcomes in the SDC group suggest that continuous compression enhances bone healing. These findings support the clinical advantage of SDC nails and their potential to improve long-term outcomes in TTC fusion. Further research should focus on the cost-effectiveness and long-term benefits of SDC devices in diverse patient populations.