Measuring Knee Laxity After Total Knee Arthroplasty using EOS Biplanar X-Ray: A First-step Phantom-based Repeatability Study

5 pages•Published: December 17, 2024

Matthew Hickey, Carolyn Anglin, Bassam Masri and Antony J. Hodgson

Abstract

Knee joint laxity or instability post total knee arthroplasty (TKA) is a common reason for patient dissatisfaction, and in some cases, can even result in the need for revision TKA. With the ultimate goal of developing an EOS-based knee joint laxity technique, the objective of this study was therefore to determine how repeatably EOS biplanar X-rays can measure 3D knee joint transforms on a radiographically realistic knee phantom between the femur and tibia in the presence of a TKA implant.
To assess repeatability, we first scanned a femoral and a tibial anatomical model (Tactile KneeTM, Tactile Orthopaedics) using a clinical CT scanner and segmented the scans semi-automatically. The fully assembled TKA phantom was then placed within a jig that maintained a fixed and rigid connection between the femur and tibia. This model was then scanned 10 times with the EOS system, with approximately equally spaced perturbations ranging up to ±300 around the superior/inferior axis, applied manually between scans. We then implemented a 2D-3D registration technique to assign Euler coordinate systems to both the femoral and tibial phantoms using JointTrack Auto. This process was completed for both the femoral and tibial TKA phantoms, and coordinate system assignment repeatability was calculated.
The mean deviations from the mean for the medial-lateral, anterior-posterior, and superior-inferior translational axes were all submillimetric: 0.6 ± 0.7 mm, 0.4 ± 0.6 mm, and 0.7 ± 0.8 mm, respectively. The mean deviation from the mean around the medial- lateral, anterior-posterior, and superior-inferior rotational axes were all on the order of 1 degree or less: 1.0 ± 1.20, 0.8 ± 1.10, and 1.0 ± 1.20, respectively.

Keyphrases: 2d/3d registration, eos biplaner xray, knee laxity

In: Joshua W Giles and Aziliz Guezou-Philippe (editors). Proceedings of The 24th Annual Meeting of the International Society for Computer Assisted Orthopaedic Surgery, vol 7, pages 88-92.

Links:	https://easychair.org/publications/paper/fvv7
	https://doi.org/10.29007/3w69

BibTeX entry

@inproceedings{CAOS2024:Measuring_Knee_Laxity_After,
  author    = {Matthew Hickey and Carolyn Anglin and Bassam Masri and Antony J. Hodgson},
  title     = {Measuring Knee Laxity After Total Knee Arthroplasty using EOS Biplanar X-Ray: A First-step Phantom-based Repeatability Study},
  booktitle = {Proceedings of The 24th Annual Meeting of the International Society for Computer Assisted Orthopaedic Surgery},
  editor    = {Joshua W Giles and Aziliz Guezou-Philippe},
  series    = {EPiC Series in Health Sciences},
  volume    = {7},
  publisher = {EasyChair},
  bibsource = {EasyChair, https://easychair.org},
  issn      = {2398-5305},
  url       = {/publications/paper/fvv7},
  doi       = {10.29007/3w69},
  pages     = {88-92},
  year      = {2024}}

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