Automated analysis of femoral over-/underhang and bone coverage of OTS TKA implants

5 pages•Published: March 8, 2024

Abstract

Implant overhang in total knee arthroplasty is associated with adverse effects with regard to postoperative pain and function, whereas implant underhang or bone undercoverage has been linked to increased risk of bleeding and osteolysis. To determine the suitability of different standard implant systems for a certain population, an automated analysis of overhang, underhang and coverage would be favorable. Therefore, we developed an automated framework for femoral implant interface fit evaluation. To evaluate this framework, we used surface models of 433 cadaver knees and of one specific femoral implant size. An analysis of the bone-implant interface fit was performed for all knees for which the available implant size was selected on the basis of the knee’s size. The analysis involved the orientation of bone and implant via reference points, the virtual resection of the bone, and the derivation and comparison of bone-implant interface contours. Implant over-/underhang was evaluated for the entire contour and in specific zones (defined in the literature). Bone coverage was calculated for the entire interface. A good agreement with the literature with regard to mean values and ranges of over-/underhang was found. Limitations include the restriction to one specific implant system and size. Future analyses should focus on different implant sizes and systems as well as on the assessment of the tibial component.

Keyphrases: bone–implant interface, over-/underhag, Total knee arthroplasty

In: Joshua W Giles (editor). Proceedings of The 22nd Annual Meeting of the International Society for Computer Assisted Orthopaedic Surgery, vol 6, pages 26--30

Links:	https://easychair.org/publications/paper/5VNq
	https://doi.org/10.29007/5636