Can avascular necrosis of the hip cause hip osteoarthritis?

The two conditions are related but not identical: avascular necrosis begins with impaired blood supply to bone, while osteoarthritis describes deterioration of the joint surfaces and associated joint changes.

In avascular necrosis, reduced blood flow weakens an area of the femoral head, the ball at the top of the thigh bone. If the weakened bone loses its rounded shape or collapses, pressure is distributed unevenly across the hip socket. Cartilage can then wear and the joint may develop secondary osteoarthritis.

Groin or buttock pain, stiffness, a limp, and difficulty bearing weight can occur as joint damage progresses. Symptoms alone cannot show whether pain comes mainly from active bone injury, arthritis, or another hip problem; examination and imaging help define the cause and stage.

Arrange an orthopaedic assessment if hip pain persists, limits walking, or is worsening. The clinician may review medicines, previous injury, alcohol exposure, and other health conditions that can affect bone blood supply, then examine hip movement and gait. X-rays can show shape change and arthritis; MRI may identify earlier bone damage when needed.

Treatment depends on how much of the femoral head is affected, whether its surface has collapsed, and the degree of arthritis. Activity modification, a walking aid, pain management, and guided exercise may reduce strain and maintain function. Joint-preserving procedures may be considered before collapse, whereas advanced collapse with painful arthritis may lead to discussion of hip replacement.

Seek prompt medical assessment for new severe hip pain, rapidly worsening pain, or sudden inability to stand or bear weight. Urgent assessment is also appropriate after a fall or injury, or when hip pain occurs with fever, a hot swollen joint, or feeling acutely unwell, because these features need evaluation for problems beyond routine arthritis care.

Ask whether imaging shows early bone injury, femoral-head collapse, cartilage loss, or a combination; whether the other hip should be assessed; which activities are suitable now; and whether the goal is to preserve the joint or manage established arthritis.