Generating 3D Pseudo-Healthy Knee-MR Images to Support Trochleoplasty Planning

Early accepted at IPCAI2025

Michael Wehrli1, Alicia Durrer1, Paul Friedrich1, Volodimir Buchakchiyskiy1, Marcus Mumme2, Edwin Li2, Gyozo Lehoczky2 Carol C. Hasler2 Philippe Claude Cattin1
1Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland, 2Department of Orthopedics, University Children's Hospital Basel, Switzerland
arXiv Code Data

Our proposed method generates pseudo-healthy MR images, restoring the trochlear shape while being conditioned on the patient’s unique patella.

Abstract

Purpose: Trochlear Dysplasia (TD) is a common malformation in adolescents, leading to anterior knee pain and instability. Surgical interventions such as trochleoplasty require precise planning to correct the trochlear groove. However, no standardized preoperative plan exists to guide surgeons in reshaping the femur. This study aims to generate patient-specific, pseudo-healthy MR images of the trochlear region that should theoretically align with the respective patient’s patella, potentially supporting the pre-operative planning of trochleoplasty.

Methods: We employ a Wavelet Diffusion Model (WDM) to generate personalized pseudo-healthy, anatomically plausible MR scans of the trochlear region. We train our model using knee MR scans of healthy subjects. During inference, we mask out pathological regions around the patella in scans of patients affected by TD, and replace them with their pseudo-healthy counterpart. An orthopedic surgeon measured the sulcus angle (SA), trochlear groove depth (TGD) and Déjour classification in MR scans before and after inpainting. The code is available at https://github.com/wehrlimi/Generate-Pseudo-Healthy-Knee-MRI. Results: The inpainting by our model significantly improves the SA, TGD and Déjour classification in a study with 49 knee MR scans.

Conclusion: This study demonstrates the potential of WDMs in providing surgeons with patient-specific guidance. By offering anatomically plausible MR scans, the method could potentially enhance the precision and preoperative planning of trochleoplasty, and pave the way to more minimally invasive surgeries.

BibTeX

@misc{wehrli2024generating3dpseudohealthyknee,
      title={Generating 3D Pseudo-Healthy Knee MR Images to Support Trochleoplasty Planning},
      author={Michael Wehrli and Alicia Durrer and Paul Friedrich and Volodimir Buchakchiyskiy and Marcus Mumme and Edwin Li and Gyozo Lehoczky and Carol C. Hasler and Philippe C. Cattin},
      year={2024},
      eprint={2412.09962},
      archivePrefix={arXiv},
      primaryClass={eess.IV},
      url={https://arxiv.org/abs/2412.09962},
}