Patient-Specific 3D-Printed Osteotomy Guides and Titanium Plates for Distal Femoral Deformities in Dogs with Lateral Patellar Luxation

Simple Summary This study describes the use of virtual surgical planning and three-dimensionally printed patient-specific guides and implants for the correction of three femoral deformities via distal femoral osteotomy in two patients with grade IV lateral patellar luxation. The use of computer-aided design software reported in this study was simple and allowed for the assessment of the degree of deformity and for the planning and simulating of the corrective osteotomy. The procurvatum was also corrected in all femurs to increase knee extension. After the surgical correction the preoperative, expected and postoperative measurements were compared to assess the efficacy of the correction performed. In all cases, weight bearing was observed two days after surgery. Virtual surgical planning combined with the use of patient-specific three-dimensionally printed osteotomy guides and titanium plates led to optimal outcomes in both patients. Patient-specific osteotomy guides reduced intraoperative time, eliminated the need for intraoperative diagnostics and ensured a more accurate osteotomy. Patient-specific titanium plates reduced surgical complications and allowed for shorter postoperative recovery times. The use of virtual surgical planning and three-dimensionally printed patient-specific instruments for distal femoral osteotomy and subsequent plate fixation ensured accurate correction of femoral deformities with good clinical outcomes.Abstract The aim of this study was to describe the diagnosis and treatment of grade IV lateral patellar luxation (LPL) in two adult large breed dogs with complex femoral deformities using patient-specific three-dimensionally (3D) printed osteotomy guides and implants. Computed tomography (CT) scans were obtained for virtual surgical planning (VSP) using computer-aided design (CAD) software, which allowed for 3D reconstruction and manipulation of the femoral deformities, providing a preoperative view of the correction. Of the two patients, one was affected bilaterally and the other unilaterally, but both dogs were from the same litter. Therefore, the healthy femur of the unilaterally affected patient was used as the physiological reference for the virtual surgical correction. Three distal femoral trapezoid osteotomies (DF-TO) followed by reduction and internal fixation with plates were performed using patient-specific 3D-printed osteotomy guides and implants. This type of osteotomy permitted correction of procurvatum in all the femurs to increase knee extension, raise the dog's lumbar spine and correct the kyphosis. Preoperative, expected and postoperative femoral angles were compared to evaluate the efficacy of virtual surgical planning and the outcome of surgical correction. Radiographic follow-up, passive range of motion and functional recovery were recorded. There were no major complications requiring revision surgery. Significant clinical improvement was observed in both patients. This study suggests that the treatment used represents a viable surgical alternative to restore limb alignment in patients with complex femoral deformities.