Accuracy of Patient-Specific Instrumentation and Comparison of a Medial versus Lateral Approach for the TATE Total Elbow Replacement System

Introduction: Total elbow replacement (TER) may be considered to improve pain and function in dogs with elbow osteoarthritis. The TATE BioMedtrix implant is a cementless, semi-constrained prosthesis with humeral and radioulnar components, designed for TER in canines. This study aimed to evaluate the alignment accuracy of TATE TER using virtual surgical planning (VSP) and novel 3D-printed patient-specific guides (PSG) via either a medial or lateral surgical approach. We hypothesized that a lateral approach would allow for more accurate positioning of the PSG, resulting in improved accuracy in COR postplacement and osteotomy location.

Materials and Methods: This was a prospective cadaveric study. All dogs underwent preoperative CT imaging of bilateral thoracic limbs and PSGs were designed. TER was performed via either a medial or lateral approach. Postoperatively, radiographs were obtained to assess COR postlocation and implant positioning.

Results: Twelve cadaveric dogs were used. Mean COR post entry location did not differ among techniques. The mean screw angle deviation was greater in the lateral approach group. Mean axial location, angulation of the osteotomy, and prosthesis placement deviation did not differ among groups (p = 0.967, p = 0.582, p = 0.244, respectively).

Discussion/Conclusion: Screw angulation in the lateral approach group was significantly greater than in the medial approach group. Theoretically, proximal angulation of the COR post from a lateral approach may result in varus alignment of the prosthesis; however, this was not observed in our study. Design modifications to the lateral PSG should be considered to increase the accuracy of COR placement. Based on these preliminary findings, both surgical approaches appear to be acceptable surgical options.

Acknowledgment

This study was partially funded in part by Movora, who covered the cost of medical imaging, surgical instruments and implants, and investigator travel, and by Thrive, who covered the cost of medical 3D printing.

Publication History

Article published online:
15 July 2025