Simple Ostectomy to Address Quadriceps Impingement Caused by Distal Femoral Malunion in Four Dogs

Introduction: In the absence of surgical reconstruction, distal femoral fractures typically progress to a malunion or nonunion, with the potential for ongoing interference with the normal action of the quadriceps. Distal femoral malunion has previously been reported in dogs, with complex surgical correction aimed at restoring sagittal plane deformities, frontal-plane deformities, and/or length discrepancies.

Materials and Methods: Four mixed breed dogs presented with a history of moderate to severe chronic pelvic limb lameness. Preoperative radiographs revealed a caudoproximally displaced distal diaphyseal/metaphyseal femoral malunion. Intraoperatively, the distal aspect of the proximal femoral segment was noted to impinge on the quadriceps. An ostectomy of this protruding bone was performed at approximately 45 degrees to the long axis of the proximal femur in the sagittal plane, with an abrasion sulcoplasty performed immediately proximal to the trochlear groove, in all dogs.

Results: Preoperatively the distal portion of the proximal femoral segment was palpable over the craniodistal thigh in all dogs. All dogs were uncomfortable on stifle manipulation. Compared with the normal contralateral femur, fractured femora had increased procurvatum and were shorter by a median of 12.7 and 11.4%, respectively. Long-term examination (in three dogs) revealed no lameness in two dogs with mild intermittent lameness in the other dog. Affected femora had a reduction in procurvatum (median 15.5%;10.2–57.9%) and an increase in length (median, 11.5%; 4.4–20.8%). Owner-completed questionnaires indicated an excellent outcome in all four dogs.

Discussion/Conclusion: In none of the cases was corrective surgery performed to address procurvatum or length disparity, and yet the long-term outcome with a simple ostectomy was good to excellent.

Acknowledgment: N/A.