Postpartum Osteonecrosis Management

Introduction

Postpartum osteonecrosis, also referred to as avascular necrosis or aseptic necrosis, is a rare condition characterized by bone death due to inadequate vascular supply that occurs during or shortly after pregnancy 1

Early diagnosis is crucial to exclude other causes of pain and allow early intervention to prevent articular collapse and joint replacement 1
MRI is the gold standard for diagnosis and staging of avascular necrosis, with assessment of necrotic volume being a critical prognostic factor, where femoral heads with ≥30% necrotic volume have 46-83% risk of collapse, and those with <30% necrotic volume have <5% risk of collapse 1, 2, 3, 4, 5, 6
The Ficat and Arlet classification is most commonly used for femoral head AVN, and necrotic volume assessment is critical, with femoral heads having ≥30% necrotic volume at 46-83% risk of collapse versus <5% risk with <30% volume 1

Core decompression is the primary surgical option for early-stage disease to prevent articular collapse and the need for joint replacement, according to the American College of Radiology 1
Resurfacing hemiarthroplasty is recommended for femoral or humeral head avascular necrosis with articular collapse 1
Total joint replacement is recommended for severe secondary osteoarthritis 1
For talar osteonecrosis, talar resection/replacement with arthroplasty or tibiotalar joint fusion is a treatment option 1
Mosaicplasty is suitable for patients under 45 years with focal full-thickness lesions less than 3 cm², offering advantages such as elimination of second procedure, superior mechanical properties, and immediate weight bearing, as indicated by the American Academy of Orthopaedic Surgeons 7
Osteochondral allograft transplantation is recommended for larger defects greater than 2.5 cm² or with substantial loss of subchondral bone, as recommended by the American Academy of Orthopaedic Surgeons 7

Corticosteroid therapy is the leading cause of non-traumatic avascular necrosis (AVN) of the hip, followed by alcohol consumption, with other risk factors including blood disorders, metabolic conditions, immunological factors, and other causes, as stated by the American College of Radiology 1, 8, 9
Immunological factors, including HIV infection and post-transplantation immunosuppression, can increase the risk of AVN, as reported by the American College of Radiology 1, 8
Modifiable risk factors such as corticosteroid use, hyperlipidemia, and alcohol consumption should be addressed, and statin therapy can be considered for hypercholesterolemia, with caution regarding drug interactions in HIV patients, as recommended by Praxis Medical Insights 4, 6
Systematic early screening with serial MRI may help reduce morbidity, though this may not be practical for routine care, as suggested by the Annals of Oncology 10

Early intervention, before subchondral collapse, significantly improves outcomes in patients with avascular necrosis, as recommended by the American College of Radiology 1
Adequate pain management is essential to prevent increased morbidity and delayed rehabilitation, with first-line analgesics including regular paracetamol (acetaminophen) administration and NSAIDs with caution, especially in elderly or those with renal dysfunction, as recommended by Praxis Medical Insights 6
Advanced pain control may involve opioids for severe pain, used cautiously with reduced dosing in renal dysfunction, and avoiding codeine due to side effects including constipation, as noted by Praxis Medical Insights 6
Physical therapy and gentle mobilization should be encouraged once acute pain subsides to restore normal gait and function, as recommended by Praxis Medical Insights 6
Recent therapeutic advances based on mesenchymal stem cells show promise for improving the functional prognosis of AVN, particularly in early stages 3
Bisphosphonates may improve bone density and prevent progression, but require calcium and vitamin D supplementation, according to Praxis Medical Insights 6