Objectives: To evaluate a juvenile dog population that sustained diaphyseal femoral fractures surgically stabilised with an angle-stable interlocking nail and evaluate for evidence of proximal femoral malformation both periooperatively and at skeletal maturity.
Materials and methods: Retrospective study of ten skeletally immature dogs sustaining diaphyseal femoral fractures stabilised using an angle-stable interlocking nail between January 2010 and June 2023. Standardised orthopaedic examination, Canine Brief Pain Inventory and radiographic review were performed at skeletal maturity. Radiographic review included subjective assessment for proximal femoral malformation and objective assessment of anatomic and mechanical angles of alignment in both the frontal and sagittal planes, immediately post-operatively, perioperatively and at long-term follow-up. A Wilcoxon signed rank test was used to assess femoral measurements using the unaffected femur as a control in each dog.
Results: Six of the nine dogs scored 0 on the Canine Brief Pain Inventory, while the remaining three had low scores (maximum of 10/100). No case had evidence of proximal femoral malformation during perioperative follow-up. Two dogs developed bilateral coxofemoral joint osteoarthritis at skeletal maturity. CORONA1 was the only significantly different measurement when comparing the surgical to the unaffected femur at skeletal maturity.
Clinical significance: Use of an angle-stable interlocking nail to stabilise femoral diaphyseal fractures in skeletally immature dogs can be performed without significant risk of developing proximal femoral malformation. Reductions in CORONA1 values may be anticipated due to reducing natural femoral procurvatum. Angle-stable interlocking nails should not be considered contraindicated for use in canine juvenile diaphyseal femoral fracture repair.
