Relationship Between Tibial and Femoral Bone Morphology and Soft Tissue Laxity of the Knee Using a PCA Model

Understanding morphological variations in bone has become an important topic, specifically for total knee arthroplasties (TKA). The need for implants to cater to differences in bone shape has been highly debated [1–2]. Equally important is understanding the relationship between bone shape and kinematic variations. Previous work has investigated the relationship of several anatomical measures on varus-valgus (VV) and internal-external (IE) laxity [3]. However, the relationship between VV and IE laxity is less understood. The first objective of this research was to understand the relationship between IE and VV laxity using a single principal component analysis (PCA) model. The second objective was to correlate the results of the laxity model with a more inclusive measure of shape variation using statistical shape modeling (SSM). The use of SSM allows for quantifications of variation between subjects to be expressed in a manner which provides a more thorough understanding of bone variation [4]. The purpose of this research was to identify the relationship between IE and VV laxity, and correlate those results with variations in bone morphology of the femur and tibia.