Finite Element Modeling of Chondrolabral Lesions in Pincer-Type Femoroacetabular Impingement.

Background: The prevalence of chondrolabral lesions due to femoroacetabular impingement (FAI) is 93% in cadaveric material. As a biomechanically determined factor, it can lead to hip destruction and early osteoarthritis in pincer-type impingement. The aim of this work was to study the biomechanism and stress-strain behavior of chondrolabral lesions in pincer-type impingement during daily activity-associated movements.

Material And Methods: The SolidWorks package was used to build a 3D pelvis model with and without pincer-type impingement in the femoroacetabular (FA) region. Finite element analysis (FEA) in ANSYS was performed to determine von Mises stress, strain and total deformations for the models during 90 hip flexion and 15 internal rotation during daily activities.

Results: Maximum stress-strain values increased 2-3.4 times in the bone along the anterior upper acetabular rim, femoral neck and acetabular labrum in the area of the pincer osteophyte compared to the non-pincer condition in the FA model.

Conclusions: 1. The increase in stress-strain in the contact area at the pincer osteophyte and femoral neck can be a factor of cam-type osteophyte formation and progression of acetabular rim ossification. 2. Daily activity can lead to an increase in maximum stress, as a factor of chondral delamination and destruction of the acetabular labrum. 3. Early surgery is needed to avoid progression of osteoarthritis in pincer-type impingement.