Osteoarthritis of the hip

Osteoarthritis (OA) of the hip is the second most common presentation of OA after the knee. It accounts for significant morbidity and total hip replacement is now one of the most common operations performed in the developed world.

Risk factors

• increasing age
• female gender (twice as common)
• obesity
• developmental dysplasia of the hip

Features

• chronic history of groin ache following exercise and relieved by rest
• red flag features suggesting an alternative cause include rest pain, night pain and morning stiffness > 2 hours
• the Oxford Hip Score is widely used to assess severity

Investigations

• NICE recommends that if the features are typical then a clinical diagnosis can be made
• otherwise plain x-rays are the first-line investigation

X-ray showing osteoarthritis of the right hip. Joint space narrowing with sclerosis, osteophyte formation and the presence of large subchondral cysts. - e Image used on license from Radiopaedia

X-ray changes of osteoarthritis (LOSS)

• Loss of joint space
• Osteophytes forming at joint margins
• Subchondral sclerosis
• Subchondral cysts