Suboptimal knee prosthesis design for Vietnamese women: a computed tomography-based arthrometric study

Area of Science:

• Orthopedic surgery
• Biomedical engineering
• Anatomy

Background:

• Mismatches between knee dimensions and total knee replacement (TKR) implant sizes can lead to suboptimal patient outcomes and dissatisfaction.
• Evaluating specific population groups, such as Vietnamese women, is crucial for optimizing TKR procedures.

Purpose of the Study:

• To characterize the knee joint morphology of Vietnamese women using 3D modeling.
• To assess the compatibility of currently available TKR prostheses with the native knee anatomy of this demographic.

Main Methods:

• Utilized full-leg CT scan datasets to create 3D knee joint models.
• Simulated femoral and tibial bone resections based on mechanical alignment.
• Measured anteroposterior (AP) and mediolateral (ML) dimensions of resected surfaces.
• Analyzed the fit and coverage percentage of six different TKR prosthesis systems.

Main Results:

• Analyzed data from 40 female patients (age 51-79) with osteoarthritis.
• Determined average distal femur dimensions (AP: 63.07 ± 3.05 mm, ML: 57.46 ± 3.06 mm) and proximal tibia dimensions (AP: 48.95 ± 3.01 mm, ML: 67.14 ± 3.49 mm).
• Observed variations in femoral aspect ratio (ML/AP) with knee size and a trade-off between tibial AP and ML dimensions.
• Found that even with optimal mismatch tolerances (±1.5 mm AP, ±3 mm ML), the best femoral component fit was only 67.5%.
• The best tibial component fit achieved 92.5% coverage at a ±3 mm tolerance for both AP and ML dimensions.

Conclusions:

• Significant discrepancies exist between the knee morphology of Vietnamese women and the dimensions of currently available TKR prostheses.
• There is a clear clinical need for the development of TKR implant designs specifically tailored to the anatomical characteristics of Vietnamese women.
• Further research is essential to engineer and validate more suitable prosthetic solutions for this population.