Hip trouble that shows up later: osteonecrosis after a crash
An orthopedic hip specialist explains bone loss from poor blood supply after an injury
A hip dislocation or fracture can cut off blood flow to the ball at the top of the thighbone. If that bone loses enough blood, part of it can die. Doctors call this osteonecrosis or avascular necrosis. Symptoms may not show up until months or years after the crash. Early cases can be hard to spot on a routine X ray. So pain that lingers needs a closer look, even if the first injury seemed to heal. [1, 2]
Describe where it hurts and what sets it off
Tell your doctor about any pain in the groin, buttock or thigh. Mention a limp, less range of motion in the hip and activities that bring on symptoms. Share your history of any hip dislocation, socket fracture or thighbone fracture. Ask if standard X rays are enough or if another scan, like an MRI, makes sense. An orthopedic hip specialist can tell osteonecrosis apart from arthritis or another cause of pain. [1, 2]
Find out what stage the bone is in
Treatment depends on how much bone is affected. It also depends on whether the rounded joint surface has started to collapse. Options may include putting less load on the hip, medicine to ease symptoms or a procedure meant to save the joint. Replacing the joint may be an option when the damage is advanced. [2]
Ask what the suggested treatment can realistically do. Find out when you need another scan or visit. Until you know the plan, stop any impact exercise that makes the pain sharply worse. [2]
Keep the hip on your follow up list
If your hip was dislocated, ask whether scheduled checks are still needed when you feel well. Call your treating team about new hip pain that won’t go away or a limp that gets worse. Get checked urgently after a new injury or if you suddenly can’t put weight on the leg. [2]
Questions for your hip specialist
- Does my injury put the femoral head, the ball of my hip, at risk?
- Which scans can confirm or rule out osteonecrosis?
- Has the joint surface collapsed, and what are my choices?
Hold on to your hip injury records
Sources and further reading
- 1National Institute of Arthritis and Musculoskeletal and Skin Diseases osteonecrosis
- 2American Academy of Orthopaedic Surgeons osteonecrosis of the hip
General education from the viewpoint of an orthopedic hip specialist. Hip pain after an injury needs a medical exam. Imaging is required to confirm the diagnosis and the stage that guides treatment.
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