Clinical and Radiographic Outcomes of Small Caliber Intramedullary Nails for Tibial Shaft Fractures.

INTRODUCTION

Tibial shaft fractures, frequently treated with intramedullary nailing (IMN), are high-risk fractures of nonunion. The effect of intramedullary nail diameter on fracture union reduction remains an area of investigation, with many surgeons anecdotally preferring to place at least a 10-mm tibial nail. We hypothesized that small-caliber nails (SCNs) (diameter ≤9 mm) are safe to use and have no difference in complication rates compared with large-caliber nails (LCNs) (≥10 mm).

METHODS

A retrospective study was conducted on patients with tibial shaft fractures undergoing reamed IMN at a level 1 trauma center between 2018 and 2022. Patient and injury characteristics, intramedullary nail diameter, surgical details, and postoperative complication rates were recorded. Nail and intramedullary canal width at the isthmus on coronal radiographs determined the nail-canal ratio. Radiographic coronal and sagittal displacement, angulations between fracture segments, and coronal plane tibial mechanical axis were evaluated on latest radiographs.

RESULTS

Among 113 patients, 68 received SCN while 45 received LCN. No difference was observed in the nail-canal ratio between the SCN and LCN groups, indicating that smaller nails were used for smaller canals. No significant demographic differences were noted between groups. LCNs were more prevalent in (AO Foundation/Orthopaedic Trauma Association classification) AO/OTA 42C (P = 0.03) and Gustilo-Anderson type III fractures (P = 0.05). The LCN group had higher rates of revision surgery (20% vs. 5.9%, P = 0.03) and wound dehiscence (8.9% vs. 0%, P = 0.02). Gustilo-Anderson IIIA fractures were independently associated with poorer outcomes overall. Radiographic parameters were comparable between groups.

CONCLUSIONS

Small-diameter and large-diameter reamed intramedullary nails can be effective in treating tibial shaft fractures. Nail-canal ratios and alignment were similar between the two groups, suggesting that surgeons should not feel obligated to ream to a 10-mm nail in a smaller patient with a well-reduced fracture.