Introduction

Femoroacetabular impingement (FAI) has recently been associated with osteoarthritic (OA) degeneration of the hip and may be responsible for up to 90% of adult idiopathic OA cases. FAI results from deformities in the hip joint which may lead to abnormal contact stresses and degeneration. The more common cam-type deformity consists of a convex anterior femoral head-neck junction which impinges the anterosuperior acetabular rim during flexion and internal rotation of the hip. Increased subchondral bone density has been reported in this region which may be a bone remodelling response to increased contact stress. The abnormal contact is expected to cause degeneration of the cartilage layer. The goal of this study was to assess the mechanical properties of cartilage retrieved from the cam deformity and to compare this with normal articular cartilage from the femoral head. It is hypothesised that the cartilage will have a lower elastic modulus and higher permeability than normal cartilage.