How to manage a patient with rheumatoid arthritis (RA) and avascular necrosis (AVN)?

Management of Rheumatoid Arthritis with Avascular Necrosis

Manage RA with AVN by aggressively controlling RA disease activity with DMARDs while minimizing glucocorticoid exposure, and promptly refer for orthopedic evaluation when AVN is symptomatic or progressing, as surgical intervention may be necessary to prevent femoral head collapse.

Immediate Assessment and Risk Stratification

• Determine AVN severity and location through MRI imaging of affected joints, as MRI is superior to conventional radiography for early detection and can identify pre-collapse stages 1
• Assess RA disease activity using validated measures (DAS28, SDAI, or CDAI) to guide treatment intensity 2, 3
• Identify glucocorticoid exposure history, as this is a major modifiable risk factor for AVN progression in RA patients 1

RA Disease Control Strategy

First-Line DMARD Therapy

• Initiate or optimize methotrexate as the anchor DMARD, starting at 15 mg/week and escalating to 20-25 mg/week or maximum tolerated dose 2
• Start DMARDs immediately upon RA diagnosis, as early aggressive treatment prevents structural damage and reduces long-term disability 2
• Combine methotrexate with short-term glucocorticoids at the lowest effective dose (prednisolone 5-7.5 mg/day equivalent), tapering as rapidly as clinically feasible to minimize AVN risk 2

Escalation for Inadequate Response

• Add a biologic DMARD or JAK inhibitor if treatment target (remission or low disease activity) is not achieved within 3-6 months, particularly when poor prognostic factors are present 2
• Prefer TNF inhibitors (adalimumab, etanercept, infliximab) or IL-6 pathway inhibitors combined with methotrexate for patients with active disease 2, 4
• Consider IL-6 inhibitors or JAK inhibitors as monotherapy if methotrexate cannot be used as comedication, as these agents have advantages over other biologics in this setting 2

Glucocorticoid Management (Critical for AVN Prevention)

• Minimize systemic glucocorticoid exposure to the lowest possible dose and shortest duration, as high-dose or pulse methylprednisolone therapy increases AVN risk 1
• Avoid methylprednisolone pulse therapy in patients with existing AVN or high-risk features, as this has been directly associated with AVN development in RA patients 1
• Taper to ≤5 mg prednisolone equivalent daily by 4-5 months when used for induction therapy 2
• Consider intra-articular glucocorticoid injections for localized disease activity rather than increasing systemic doses 2

Monitoring Protocol

• Assess disease activity every 1-3 months during active disease until treatment target is achieved 2, 3
• Perform serial MRI imaging of affected joints every 6-12 months to monitor AVN progression, as radiographic changes lag behind MRI findings 1
• Screen for treatment-related complications including cardiovascular risk factors, infections, and bone health 2

Surgical Referral Indications

• Refer urgently to orthopedic surgery when patients develop symptomatic AVN with pain, functional limitation, or radiographic evidence of femoral head collapse 1, 5
• Consider total hip arthroplasty for advanced AVN with femoral head collapse or protrusio acetabuli, as this can restore function and improve pelvic mechanics 5
• Evaluate for core decompression in early-stage AVN before collapse occurs, though evidence in RA patients is limited 1

Comorbidity Management

• Assess cardiovascular risk annually using national guidelines with a 1.5 multiplication factor for RA patients meeting high-risk criteria (disease duration >10 years, RF/anti-CCP positive, or extra-articular manifestations) 2
• Optimize bone health with calcium, vitamin D supplementation, and bisphosphonates when indicated, particularly in glucocorticoid-exposed patients 2
• Address altered biomechanics from AVN or protrusio acetabuli, as these can lead to stress fractures in osteoporotic bone 5

Common Pitfalls to Avoid

• Do not delay DMARD escalation waiting for glucocorticoids alone to control disease, as this prolongs exposure to both active inflammation and steroids 2
• Do not rely on conventional radiography alone for AVN monitoring, as MRI detects changes 6-12 months earlier 1
• Do not assume asymptomatic MRI changes are benign, as some AVN lesions can progress to collapse even without initial symptoms 1
• Do not combine multiple biologic DMARDs, as this increases infection risk without added benefit 4

Treatment Target and Reassessment

• Aim for sustained remission or low disease activity as the therapeutic target for all RA patients 2
• Adjust therapy if no improvement by 3 months or target not reached by 6 months 2
• Continue remission-maintenance therapy for at least 24 months once sustained remission is achieved 2