Comparing the Accuracy of Patient-Specific Guide and Universal Guide for Distal Femoral Osteotomy in Dogs

Objective To introduce a novel universal guide design for distal femoral osteotomy (DFO) to treat femoral deformities and other hindlimb orthopaedic diseases, and to compare its accuracy to the patient-specific guide in vitro and ex vivo on X-ray and computed tomography (CT). Methods Thirteen anatomic specimens of canine femurs and 13 3D-printed femoral bone models were subjected to DFO using a patient-specific and a universal guide. The anatomical lateral distal femoral angle and anteversion angle were measured on radiographic and CT images before and after surgical procedure and used to compare the accuracy of the surgical guides in treating uniplanar or biplanar deformities. Bone models were used to compare the accuracy with ex vivo models. Results The mean correction errors were -1.18 degrees to 0.72 degrees on X-ray and -1.91 degrees to 0.53 degrees on CT scan. The analysis showed no statistically significant difference in the mean error between the groups based on type of guide used, nor in the mean error between groups based on whether anteversion correction was performed based on both the CT and X-ray imaging data. Conclusion Both the patient-specific and universal guides can produce accurate results in DFO surgery, and the universal guide shows potential as a useful surgical tool.