Treatment of Stage 2 Avascular Necrosis of the Hip
For stage 2 AVN of the hip, core decompression is the recommended first-line surgical intervention, with success rates of approximately 63%, while conservative management with protected weight-bearing, bisphosphonates, and NSAIDs should be reserved for carefully selected early stage 2 cases without significant symptoms. 1, 2, 3
Surgical Management: Core Decompression
Core decompression is the primary treatment for stage 2 AVN and demonstrates statistically superior outcomes compared to conservative treatment at this stage. 3
- Core decompression achieves a 63% success rate in stage II disease, significantly better than the 59% success rate with conservative treatment alone 3
- The procedure aims to relieve intraosseous pressure in the femoral head and restore blood supply 4
- Core decompression with bone substitute filling is specifically recommended for early-stage disease, particularly in younger patients 2
- Lesions involving less than 30% of the femoral head have less than 5% progression to collapse, making these ideal candidates for core decompression 5, 2
Technical Considerations
- 3D-printed guide plates can improve surgical precision, decrease operative time, and reduce blood loss during the procedure 5
- CT imaging is valuable for preoperative planning, showing the location and extent of articular collapse that may not be visible on radiographs 5
Conservative Management Options
Conservative treatment may be considered in highly selected stage 2 cases, particularly those who are asymptomatic or have minimal symptoms, but outcomes are inferior to surgical intervention. 2, 6
Protected Weight-Bearing
- Protected weight-bearing is the cornerstone of early management and should be implemented immediately 2
- Weight reduction and walking aids (canes or walkers) help reduce symptoms in early stages 1, 2
- Weight-bearing restriction as a stand-alone therapy is insufficient in preventing disease progression but may be useful when combined with pharmacological agents 6
Pharmacological Treatment
Bisphosphonates:
- May prevent bone collapse in early stages of AVN 1, 2
- Might be efficient in early stages of disease, though there are no clear recommendations on length of treatment and therapeutic dosage 6
- Should be considered in pre-collapse stage in selected cases, given limited evidence and potential side effects 6
NSAIDs and Analgesics:
- Provide symptomatic pain relief but do not alter disease progression 1
- Should be used as adjunctive therapy for symptom management 1
Other Conservative Modalities (Limited Evidence)
- Low molecular weight heparin could lower disease progression in idiopathic AVN, but quality of evidence is very low 6
- Extracorporeal shock wave therapy may improve pain and function in early stages with low evidence, but doesn't significantly change time to femoral head collapse 6
- Statins, vasodilators, hyperbaric oxygen therapy, and pulsed electromagnetic fields have insufficient evidence to recommend 6
Postoperative Management
- Protected weight-bearing is mandatory following core decompression procedures 5
- Regular follow-up with radiographic evaluation is essential to monitor disease progression 5
- MRI is the preferred imaging modality for monitoring, as both hips should be evaluated since AVN can be bilateral 1, 2
Critical Prognostic Factors
- Late presentation is a major negative prognostic factor 1, 2
- Untreated AVN inevitably leads to early degenerative joint disease 1, 2
- AVN causes up to one-third of all total hip arthroplasties in patients under 60 years of age 1, 2
- Femoral head collapse typically occurs within 2-3 years without intervention, at which point arthroplasty becomes necessary 4
Special Populations
Young patients with anatomical abnormalities:
- For young adults with symptomatic hip AVN, especially with dysplasia or varus/valgus deformity, joint-preserving procedures such as osteotomy may be considered 1, 2
Sickle cell disease patients: