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. 2024 Sep 6;16(9):e68769.
doi: 10.7759/cureus.68769. eCollection 2024 Sep.

Angle Accuracy of Intramedullary Bone Resection Guides for Total Knee Arthroplasty

Matthew C Kane  1 , Harold E Cates  2 , Iou-Ren Chang  3
Affiliations

Angle Accuracy of Intramedullary Bone Resection Guides for Total Knee Arthroplasty

Matthew C Kane et al. Cureus. .

Abstract

The importance of proper prosthetic placement has been confirmed in numerous studies. The objective of this study was to compare the planned resection angles to the verified intraoperative angles of femoral and tibial varus/valgus, tibial slope, and femoral flexion for each total knee performed using intramedullary (IM) cut guides for both distal femur and proximal tibia cuts. A total of 1,000 total knee arthroplasties (TKAs) were evaluated for this study. Intraoperative cut-check technology was used to show real-time validation of these resection angles. Assuming an acceptable range of within 2° of the planned cuts, results show the femoral varus/valgus angles were 75% accurate, the femoral flexion angles were 50.8% accurate, the tibial cuts were 95.2% accurate in the coronal plane, and the tibial slope was the least accurate with only 50.3% within the acceptable range. This showed that IM guides are reasonably accurate in producing desired angles in the coronal plane but less accurate in the sagittal plane, with a greater number of outliers in femoral flexion and posterior slope. Surgeons need to be aware of potential cutting errors when using IM guides as they affect the overall alignment of the implant, and real-time verification technology is available to verify the accuracy of the cuts.

Keywords: angle accuracy; intramedullary guide; robotic total knee arthroplasty; total knee arthroplasty (tka); total knee arthroplasty technique.

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Conflict of interest statement

Human subjects: Consent was obtained or waived by all participants in this study. Covenant Health IRB issued approval 2021-377. IRB approval was obtained through the Covenant Health IRB: 2021-377. The Tennessee Orthopedic Foundation for Education and Research works in association with Covenant Health at their facilities and is regulated by the Covenant Health IRB Board. The authors each worked on this project through the Tennessee Orthopedic Foundation for Education and Research. In particular, H.E. Cates, MD, an orthopedic surgeon with the Tennessee Orthopedic Alliance continues his work within the Tennessee Orthopedic Foundation for Education and Research, while I.R. Chang, MD, is currently an orthopedic surgeon working for OhioHealth Doctor's Hospital, and M.C. Kane, MS, is currently a medical student at East Tennessee State University Quillen College of Medicine. . Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work.

Figures

Figure 1
Figure 1. Femoral cut: flexion/extension variance
Values that fall between the vertical gray lines are within 2° of the planned cut angle and were deemed within the acceptable range of variance. Values outside of this range were considered outliers and were subject to recut at the surgeon's discretion.
Figure 2
Figure 2. Femoral cut: varus valgus variance
Values that fall between the vertical gray lines are within 2° of the planned cut angle and were deemed within the acceptable range of variance. Values outside of this range were considered outliers and were subject to recut at the surgeon's discretion.
Figure 3
Figure 3. Tibial cut: posterior slope variance
Values that fall between the vertical gray lines are within 2° of the planned cut angle and were deemed within the acceptable range of variance. Values outside of this range were considered outliers and were subject to recut at the surgeon's discretion.
Figure 4
Figure 4. Tibial cut: varus valgus variance
Values that fall between the vertical gray lines are within 2° of the planned cut angle and were deemed within the acceptable range of variance. Values outside of this range were considered outliers and were subject to recut at the surgeon's discretion.
See this image and copyright information in PMC

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