Size-Up, Size-Down: Accuracy of Component Sizing with Computerized Tomography and Robotic-Assisted Total Knee...

Area of Science:

• Orthopaedic Surgery
• Medical Imaging
• Biomedical Engineering

Background:

• Preoperative templating in total knee arthroplasty (TKA) aims to enhance surgical efficiency, alignment, and patient outcomes.
• Computed tomography (CT)-based templating is a key tool for planning implant selection.

Purpose of the Study:

• To evaluate the accuracy of CT-based preoperative templating in predicting final implant sizes for TKA.
• To compare the accuracy of templating performed by a company representative (MAKO Product Specialist, MPS) versus combined surgeon and MPS input.

Main Methods:

• Retrospective evaluation of 724 Stryker MAKO robotic-assisted TKA cases from a prospectively collected database (January 2020 - October 2023).
• Comparison of final tibial and femoral component sizes with preoperative templates.
• Analysis of templating performed solely by MPS versus combined surgeon and MPS input.

Main Results:

• MPS alone predicted final tibial and femoral implants within one size in 97.2% and 97.8% of cases, respectively.
• Combined surgeon and MPS templating improved accuracy to 98.9% for tibial and 99.5% for femoral components.
• Patient height and weight positively correlated with final implant size (p < 0.001).

Conclusions:

• Non-surgeons can reliably predict implant sizes using CT-based preoperative templating.
• Surgeon involvement further refines templating accuracy, optimizing TKA planning.
• Accurate templating can reduce trial implant usage, decrease costs, and improve operating room efficiency.