Objective: To describe and evaluate minimally invasive repair of acetabular fractures in dogs using plates contoured to 3D-printed hemipelvic models.
Study design: Ex vivo feasibility study and case report.
Sample population: Adult canine cadavers (n = 5); 8 year old male neutered Chihuahua.
Methods: Bone plates were contoured to 3D printed hemipelvic models derived from computed tomographic scans of each dog. In cadavers, acetabular, ischial, and pubic osteotomies were performed. A small craniolateral approach to the ilial body and a caudal approach to the ischium were made and connected through epiperiosteal tunnels. Under fluoroscopic guidance, fractures were reduced, and precontoured bone plates were applied with locking screws. Postoperative computed tomographic images were used to assess fracture gaps, step defects, and pelvic angulation. Cadavers were dissected for subjective assessment of sciatic nerve injury. Radiographic and clinical follow up was acquired for the clinical case.
Results: Small fracture gaps (<2 mm) and step defects (<1 mm), low pelvic angulation (<5°), and minimal (none n = 4 and mild n = 1) sciatic nerve injuries were observed in cadaver testing. There was slight (~1 mm) medial displacement of the pubic segment and good functional outcome for the clinical case, with radiographic healing documented at 3 months postoperatively.
Conclusion: Minimally invasive acetabular fracture repair in dogs with the aid of 3D printing was feasible and accurate.
Clinical significance: Minimally invasive repair techniques assisted by 3D printing may be applicable for acetabular fractures in dogs. The technique should be evaluated further before routine use can be recommended.