Treatment for avascular necrosis of the hip depends on the stage of the disease. Early-stage disease may be treated with core decompression to preserve the joint; advanced disease requires total hip replacement.
ℹ️ Pre-operative assessment includes blood tests, health check, and medication review. MRI staging of the femoral head is essential before surgery.
Core decompression takes approximately 30-45 minutes under general or regional anaesthetic. Total hip replacement takes approximately 60-90 minutes. Both may be performed as day-cases or with a short hospital stay.
Core decompression is only effective in early-stage disease (Ficat I-IIa). Advanced collapse (Ficat IIb-IV) requires hip replacement. Ensure staging MRI has been reviewed by your surgeon.
Blood thinners and NSAIDs paused before surgery. If you are on long-term steroids, do not stop without your medical team's advice - your dose may need adjusting around surgery.
If corticosteroid use or alcohol excess caused the AVN, discuss reduction or cessation with your medical team before surgery. Ongoing exposure to the cause increases the risk of progression and of AVN developing in the other hip.
Up to 80% of patients with AVN have bilateral involvement. Ensure the contralateral hip has been assessed by MRI before surgery.
For total hip replacement, raise the toilet seat, install a shower grab rail, and arrange ground floor living for the first 2 weeks if possible. Core decompression as a day-case requires less home modification but you will still need someone at home for the first 24-48 hours.
ℹ️ You will be given a specific arrival time. Do not eat or drink (other than clear water up to 2 hours before) from midnight the night before. Bring your medication list and any documents sent by the hospital.
You will be admitted to the ward or day surgery unit, change into a gown, and be seen by the nursing, anaesthetic, and surgical teams before theatre.
Your surgeon will confirm the procedure, mark the operative side, and you will sign a consent form before going to theatre.
You will meet the anaesthetist in the anaesthetic room. Once anaesthesia is established, the procedure will begin.
After surgery you will wake in the recovery room where nurses monitor your vital signs until you are stable and comfortable.
Most patients having arthroscopic or day-case procedures go home on the day of surgery. Those having joint replacement typically stay 1–2 nights. Before discharge, the team will check your pain is controlled, give you wound care instructions, and confirm your follow-up appointment.
You will be given oral pain relief before discharge. Take it regularly for the first 48 hours rather than waiting until pain is severe.
A nurse will check the wound before you leave and explain how to keep it clean and dry.
You will receive a letter for your GP and details of your next outpatient appointment - usually at 2 weeks for a wound check.
Arrange for a family member or friend to collect you. You must not drive on the day of surgery if you have had a general anaesthetic or sedation.
⚠️ Important: If you have been treated with core decompression and develop sudden worsening of hip pain or a sense of the hip giving way, attend your nearest A&E. This may indicate femoral head collapse requiring urgent assessment. After hip replacement, seek urgent assessment for wound infection signs (redness, heat, discharge, fever) or sudden severe hip pain.
Avoid getting the wound wet until it is fully healed - usually 10–14 days. Use a waterproof cover or cling film when showering.
Do not wait until pain is severe before taking medication. Regular simple analgesia (paracetamol, ibuprofen if appropriate) is more effective.
This is usually 2 weeks after surgery. Sutures or clips will be removed if used.
Seek urgent advice if you develop increasing redness, warmth, swelling, discharge from the wound, or a temperature above 38°C - these may indicate infection.
Core decompression: 30-45 minutes, usually day-case. Hip replacement: 60-90 minutes, 2-3 nights in hospital.
Crutches for 4-6 weeks after core decompression to reduce load on the healing femoral head. Full weight-bearing immediately after hip replacement.
After core decompression: gradual return to walking and low-impact activity. After hip replacement: progress from crutches to a stick to unaided walking.
Most patients return to driving at 6-8 weeks once strength and reflexes are restored. Confirm with your insurer.
Regular X-ray and MRI monitoring is required after core decompression to detect any progression to femoral head collapse. The opposite hip is also monitored where MRI changes are present.
Core decompression is successful in preventing progression in approximately 50-75% of patients with early-stage disease (Ficat I-IIa). Success rates are lower for larger lesions and higher Ficat stages. Regular monitoring with MRI is essential after the procedure.
The surgical technique is similar, but patients with AVN are often younger and may have underlying conditions that affect anaesthetic risk or bone quality. Long-term implant survival may be slightly lower than for primary OA, and revision surgery rates over a lifetime are higher in younger patients.
Yes - up to 80% of patients with AVN in one hip have changes in the other, often without symptoms. Both hips are usually imaged at the time of diagnosis and monitored with periodic MRI if early changes are present. Treating the underlying cause (steroid reduction, alcohol cessation) reduces the risk of progression.
For very early-stage disease, observation with risk-factor modification (reducing steroids, stopping alcohol) and bisphosphonate medication may be tried. However, once symptoms develop, surgical treatment is usually required - the natural history of symptomatic AVN is progression to collapse and arthritis without intervention.
Core decompression: aims to prevent or slow the progression of femoral head collapse in early-stage disease by reducing intraosseous pressure and stimulating a healing response. Total hip replacement: provides reliable pain relief when significant femoral head collapse has occurred.
Core decompression: under general or regional anaesthetic, one or more drill holes are made into the necrotic area of the femoral head through the lateral femoral cortex under fluoroscopic guidance. May be combined with bone grafting or growth factor injection. Takes approximately 30-45 minutes. Total hip replacement: same as for primary hip OA. See hip replacement consent information.
Analgesics, activity modification, and elimination of risk factors (corticosteroid reduction or cessation, alcohol cessation). Non-weight-bearing with crutches may slow progression in very early disease but does not prevent collapse if blood supply is lost.
Addition of bone grafting, platelet-rich plasma, or stem cell injection to core decompression may improve outcomes in early-stage disease. Evidence is evolving.
For advanced disease with significant collapse (Ficat IIb-IV), hip replacement is the appropriate treatment.
For very small lesions in asymptomatic patients, monitoring with regular MRI may be appropriate.
The drill holes created during core decompression weaken the femoral neck, creating a risk of fracture during the period of protected weight-bearing.
Wound or bone infection.
Core decompression does not halt progression in all patients. Regular MRI monitoring is required to detect progressive collapse requiring hip replacement.
See hip replacement consent information for full list of replacement-related risks.
Expected after core decompression.
Crutches are required for 4-6 weeks after core decompression.
Without surgery, early-stage AVN will progress to femoral head collapse in most patients. The natural history of AVN is progression - conservative management alone rarely prevents collapse once the diagnosis is established. Early surgery (core decompression) in Ficat Stage I-IIa gives the best chance of preventing the need for hip replacement.