Accuracy of fluoroscopy-guided osteotomy placement in TPLO: Postoperative tibial plateau angle and preoperative planning evaluation.

Objective: To evaluate the accuracy of achieving a predetermined postoperative tibial plateau angle (TPA) using fluoroscopy-assisted osteotomy planning and positioning, and to assess the reproducibility of preoperative tibial plateau leveling osteotomy (TPLO) radiographic measurements intraoperatively.

Study design: Prospective observational study.

Animal population: A total of 25 client owned dogs undergoing TPLO.

Methods: Dogs undergoing TPLO with 21 mm osteotomy blades were enrolled. Intraoperatively, fluoroscopy was used to identify the intercondylar eminence (intended center of rotation), which was marked with a 0.035-inch Kirschner wire. The osteotomy site was dynamically adjusted to maintain a 21 mm radius from the center of rotation before proceeding with the osteotomy. Preoperative radiographic measurements (D1 and D2) were compared to intraoperative fluoroscopic measurements (R1 and R2) to assess reproducibility. Postoperative TPA was measured on routine radiographs.

Results: A total of 30 TPLOs were performed. The median postoperative TPA based on fluoroscopic guidance was 3° (range: 0-4°). The median absolute difference between R1 and 21 mm was 0.5 mm (range: 0.0-3.0 mm), while the difference between R2 and 21 mm was 2.5 mm (range: 0.0-4.0 mm). D1 measurements demonstrated greater intraoperative reproducibility than D2.

Conclusion: Fluoroscopy-assisted osteotomy placement resulted in precise postoperative TPA alignment with minimal deviation. Preoperative radiographic measurements were reproducible intraoperatively, with D1 showing higher accuracy than D2.

Clinical significance: Intraoperative fluoroscopy improves the accuracy of osteotomy placement, leading to more precise postoperative TPA and potentially reducing surgical variability.