Total hip arthroplasty (THA) is a surgical procedure used to treat hip pain from joint laxity and osteoarthritis in dogs, with a success rate of 80-98%. Proper positioning of the required implants (including femoral stem) is very important. Prior to femoral stem placement, the surgeon prepares the femur using a process called reaming. Improper reaming or resultant imperfect stem placement increases the risk of major complications such as fracture or hip dislocation. The use of intra-operative fluoroscopy (similar to an x-ray) has been recommended to improve surgical accuracy, but radiation exposure is a concern. One study has reported the use of a patient-specific surgical guide (PSG) for femoral reaming, but the results were not compared to the conventional free-handed technique. The objective of the current study is to evaluate the accuracy of femoral reaming when using PSGs as compared to free-handed reaming. We hypothesize that the use of PSGs will provide a >50% improvement in accuracy of femoral reaming compared to free-handed reaming for a surgeon with moderate THA experience.

The study will be performed using 20 dog cadavers to simulate the surgical experience. A single surgeon with moderate THA experience will perform free-handed reaming on one side first, followed by PSG femoral reaming on the other side, for an internally controlled design with procedural sidedness randomly assigned and evenly distributed. After reaming, computed tomography (CT) imaging will be performed, and the accuracy of reaming trajectory will be assessed by a participant blinded to the treatment group to minimize bias.