Minimally invasive osteosynthesis using a dynamic compression angle-stable interlocking nail in feline transverse femoral fractures: an ex vivo study.

OBJECTIVE

To evaluate the effectiveness of interfragmentary compression in feline femoral transverse fractures treated with a dynamic compression angle-stable interlocking nail implanted via minimally invasive nail osteosynthesis.

METHODS

Thirty femurs from 15 feline cadavers were allocated into three groups according to fracture location (n = 10 per group): proximal (GPD), mid- (GMD) and distal diaphysis (GDD). Radiographic and computed tomography scans were performed preoperatively for surgical planning and measurement of the anatomical lateral distal femoral angle, anatomical lateral proximal femoral angle and femoral torsion angle. Standardised transverse osteotomies were created per group allocation and stabilised using dynamic compression angle-stable interlocking nail implanted via minimally invasive nail osteosynthesis technique. Postoperative imaging assessed residual fracture gap and femoral angles. Data were analysed using one-way ANOVA with Tukey's post hoc test, and effect sizes were estimated using generalised eta squared (ges).

RESULTS

All groups achieved effective interfragmentary compression, with residual fracture gaps <1 mm (range: 0 to 0.3 mm). The anatomical lateral distal femoral angle remained consistent before and after osteosynthesis. The anatomical lateral proximal femoral angle remained unchanged in proximal diaphysis and distal diaphysis but showed a moderate increase in mid-diaphysis (ges = .445). The femoral torsion angle increased in all groups postoperatively, with large, moderate and small effect sizes in proximal diaphysis (ges = .655), mid-diaphysis (ges = .385) and distal diaphysis (ges = .213), respectively.

CLINICAL SIGNIFICANCE: Dynamic compression angle-stable interlocking nail provided consistent interfragmentary compression. However, deviations in the transverse plane were observed following the minimally invasive nail osteosynthesis approach. These findings support dynamic compression angle-stable interlocking nail as a promising option for stabilising femoral transverse fractures in cats.