Visit preparation
Can the hip joint still be preserved after femoral head collapse?
Mild collapse caused by osteonecrosis can still be assessed for hip preservation. With more severe collapse or arthritis, the doctor will focus on whether hip replacement is appropriate.
What should I look for in the imaging report?
Chinese orthopaedic guidance places a fracture beneath the cartilage or collapse of the femoral head in stage III of the ARCO system. The distinction between stages IIIA and IIIB is whether the depression exceeds 2 mm. In stage IV, imaging shows signs of arthritis, such as a narrowed joint space. Ask your doctor to point out where the head has collapsed and how much of it is affected. [1]
How do preservation and replacement compare?
| Imaging finding | What the orthopaedic specialist assesses | How it affects the discussion |
|---|---|---|
| Depression of 2 mm or less, within ARCO stage IIIA | Whether the affected bone reaches the weight-bearing area and how well the hip works | It may be possible to discuss preserving the natural femoral head |
| Depression of more than 2 mm, within ARCO stage IIIB | Extent of collapse, pain and limits on activity | The specialist assesses the options for preservation alongside replacement |
| Arthritis changes, within ARCO stage IV | Damage to the hip socket and femoral head and limits on walking | With significant pain or impaired function, replacement becomes a main option to discuss |
The 2 mm measurement describes the imaging stage. The location of bone damage, joint damage and your current function also matter. Tell the specialist how far you can walk, whether stairs are difficult and how pain affects your daily life. [1]
Which scans should I bring?
Give the hip specialist the original X-rays, MRI or CT images and their reports. Label the dates and the side examined. If you have two or more sets of images, put them in date order so the doctor can check whether the collapse has progressed. The guideline uses MRI to detect and assess the affected area and CT to show changes in bone, including fractures beneath the cartilage and collapse. [1]
Frequently asked questions
Can I still be assessed for hip replacement after an earlier hip-preserving operation?
Yes. Previous preservation surgery can make replacement technically more difficult. Bring the operative report and previous scans for the orthopaedic assessment. [1]
Need help?
Tell us about your situation and needs. Incomplete records are welcome.