Principal component analysis as a tool for determining optimal tibial baseplate geometry in modern TKA design

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Medical Imaging Analysis

Background:

• Optimal tibial component fixation in total knee arthroplasty (TKA) necessitates maximal bone coverage, precise mediolateral cortical fit, and correct component rotation.
• Improper fit, whether undersized (leading to subsidence/loosening) or oversized (causing overhang/impingement), compromises TKA outcomes.
• Current lack of consensus on ideal tibial component shape and significant manufacturer variability highlight the need for data-driven design.

Purpose of the Study:

• To determine the ideal tibia baseplate shape for total knee arthroplasty using principal component analysis.
• To analyze anthropometric CT scan data to define an average proximal tibial shape and its variations.
• To evaluate gender specificity and differences in proximal tibial geometry based on anatomical constitution (varus, neutral, valgus).

Main Methods:

• Utilized principal component analysis (PCA) as a statistical tool to analyze anthropometric computed tomography (CT) scan data.
• Defined an average proximal tibial shape and quantified variations within a study cohort.
• Assessed gender-specific geometric differences and variations related to varus, neutral, and valgus anatomical constitutions.

Main Results:

• Proximal tibial morphology at the resection level in arthritic knees is predominantly influenced by patient size.
• This size-dependent variation in morphology is consistent across both Caucasian men and women.
• The observed morphological differences are independent of the patient's anatomical constitution (varus, neutral, or valgus alignment).

Conclusions:

• Tibial component design for total knee arthroplasty should prioritize size-adaptive strategies over shape-specific designs.
• The findings suggest that a single 'ideal' tibial component shape may not be universally applicable due to size being the primary differentiator.
• Future TKA component development could benefit from focusing on scalable designs that accommodate the observed size variations in proximal tibial morphology.