Relationship between joint shape and the development of osteoarthritis

Abstract

Purpose of review: To present an updated summary of the relationship between joint shape and the development of osteoarthritis, with a particular focus on osteoarthritis of the hip.

Recent findings: Osteoarthritis of the hip is highly heritable, with a genetic contribution estimated at 60%. Among the genes that have been linked to this disease are several that are involved in the development and maintenance of joint shape, including members of the Wingless (Wnt) and the bone morphogenetic protein (BMP) family. Several features of hip joint architecture, such as acetabular dysplasia, pistol grip deformity, wide femoral neck, altered femoral neck-shaft angle, appear to play an important role in the pathogenesis of osteoarthritis and may predate the development of osteoarthritis by decades.

Summary: Gene-environment interactions play a crucial role in the development of osteoarthritis. The architecture of joint shape is determined by a complex sequence spanning embryonic, childhood, and adult life and contributes to the pathogenesis of osteoarthritis.

Figure 1. Various femoral head and acetabular shape variants are associated with osteoarthritis

For example, a shallow acetabular cup is one type of acetabular dysplasia that is linked to incident osteoarthritis. In addition, a nonspherical, elongaged femoral head is a cause of the so-called ‘pistol grip’ deformity, which is associated with impingement and early osteoarthritis.