Can You Get AVN of the Humeral Head from Steroid Injections?
Yes, avascular necrosis (AVN) of the humeral head can occur following corticosteroid injections, though the evidence is stronger for systemic corticosteroid use than for local injections.
Understanding the Risk
The ACR Appropriateness Criteria explicitly identifies corticosteroid therapy as a major risk factor for osteonecrosis, including the humeral head 1. The humeral head is the second most common site for AVN after the femoral head, and in patients on systemic steroids, shoulder involvement occurs in approximately 15% of cases 1.
Systemic vs. Local Corticosteroid Risk
The evidence base differs significantly between these two routes:
Systemic corticosteroids (oral/IV):
- Well-established causative relationship 2, 3, 4
- Dose-dependent and cumulative effect 5
- Can cause bilateral and multifocal AVN affecting hips (68%), knees (44%), ankles (17%), and shoulders (15%) 1
- Symptoms typically develop 2-3 months after exposure (mean 79 days) 5
Local intra-articular injections:
- The evidence is primarily from hip injection studies, showing AVN incidence of 0.6-20.4% 6
- Risk factors for post-injection AVN include: elevated BMI, history of cancer therapy, low vitamin D, and multiple injections (p=0.004) 6
- Direct evidence for shoulder injections causing humeral head AVN is limited to case reports 7
Clinical Implications and Pitfalls
Critical caveat: One case report describes a patient who received an intra-articular corticosteroid injection for humeral head AVN treatment 7, highlighting that injections may be used therapeutically rather than being causative. This underscores the importance of distinguishing correlation from causation.
Key Risk Stratification Points
When evaluating a patient with humeral head AVN and steroid exposure history:
- Timing matters: AVN symptoms typically emerge 2-3 months post-exposure 5
- Look for multifocal disease: Check hips and knees, as 70-80% of non-traumatic cases are bilateral or multifocal 1, 3
- Assess cumulative exposure: Multiple injections increase risk more than single injections 6
- Screen for other risk factors: Alcohol use, HIV, blood dyscrasias, chemotherapy, radiation, Gaucher disease 1
Diagnostic Approach
MRI is the most sensitive imaging modality for early detection 8. Plain radiographs may be normal in early stages, showing changes only after subchondral collapse has occurred 4.
Management Algorithm
The treatment pathway depends on disease stage per the Cruess classification 8:
Early stages (pre-collapse):
- Risk factor modification (discontinue steroids if possible)
- Physical therapy with pendulum exercises
- Avoid abduction against resistance 4
- Consider core decompression or vascularized bone grafts 2, 8
- Important: Conservative management carries progression risk and doesn't alter disease course 8
Late stages (with collapse):
- Shoulder arthroplasty (hemiarthroplasty or total shoulder replacement) 2, 4
- Pyrocarbon implants may reduce glenoid erosion 8
- Historical data shows excellent results with Neer's prosthesis after 1-7 years 4
Bottom Line
While systemic corticosteroid use clearly causes humeral head AVN, the relationship with local shoulder injections remains less definitively established compared to hip injections. Exercise heightened vigilance in patients receiving multiple shoulder injections, particularly those with additional risk factors (obesity, vitamin D deficiency, cancer therapy history). The absence of high-quality evidence doesn't eliminate risk—it reflects underreporting and the insidious nature of this condition 1.