Nailing approach and residual fracture gap: A comparative study of antegrade versus retrograde fixation in distal femoral shaft fractures.

BACKGROUND

The optimal nailing approach for simple distal femoral shaft fractures located below the isthmus remains controversial. A critical factor that may affect union is the residual fracture gap created during intramedullary nail insertion. This study aimed to compare antegrade and retrograde nailing techniques in terms of residual fracture gap, time to union, and functional outcomes.

METHODS

This retrospective study included 50 patients (21 antegrade, 29 retrograde) with transverse or short oblique femoral shaft fractures distal to the isthmus. Residual fracture gap, union time, modified radiographic union scale for tibial fractures scores, Visual Analog Scale scores, and lower extremity functional scale were evaluated. Radiographic measurements were performed by two independent blinded observers, and statistical comparisons were conducted using appropriate parametric and non-parametric tests.

RESULTS

The residual fracture gap was significantly larger in the retrograde group compared with the antegrade group on both the anteroposterior view (4.8±2.6 mm vs. 2.1±1.4 mm; p=0.006) and the lateral view (5.6±2.9 mm vs. 2.6±1.8 mm; p<0.0001). Time to radiographic union was significantly longer in the retrograde group (20.2±5.2 weeks vs. 16.0±4.6 weeks; p=0.030). However, there were no significant differences in non-union rates, functional scores, or complications.

CONCLUSION

In distal femoral shaft fractures located below the isthmus, retrograde nailing was associated with larger residual fracture gaps and longer time to union. Although both techniques remain viable, attention should be directed toward minimizing distraction during retrograde nail placement to optimize healing.