Progression of knee osteonecrosis on MRI

Area of Science:

• Radiology
• Orthopedics
• Rheumatology

Background:

• Osteonecrosis (ON) diagnosis and monitoring rely heavily on Magnetic Resonance Imaging (MRI) due to its high sensitivity and specificity.
• Corticosteroid therapy, while crucial for managing conditions like Sjogren disease-related interstitial nephritis, can be associated with an increased risk of osteonecrosis.
• Monitoring treatment efficacy and disease progression in patients at risk for ON is essential for optimal patient outcomes.

Observation:

• A 40-year-old female patient with Sjogren disease-related interstitial nephritis presented with deteriorating renal function requiring corticosteroid initiation.
• The patient subsequently developed osteonecrosis (ON) of the knee, which was monitored using serial Magnetic Resonance Imaging (MRI).
• The MRI findings demonstrated progression of ON, characterized by increasing degrees of surrounding bone marrow edema.

Findings:

• The degree of bone marrow edema observed on MRI correlated directly with the patient's reported knee pain and functional limitation.
• Serial MRI scans allowed for objective assessment of ON progression and the extent of inflammatory changes in the bone marrow.
• This case highlights the utility of MRI in visualizing and quantifying the inflammatory response associated with corticosteroid-induced ON.

Implications:

• This case underscores the importance of vigilant MRI monitoring for osteonecrosis in patients undergoing corticosteroid therapy, particularly those with autoimmune conditions.
• Correlating imaging findings with clinical symptoms provides a comprehensive understanding of disease activity and patient well-being.
• Early detection and monitoring of ON progression via MRI can guide therapeutic adjustments and potentially mitigate long-term joint damage.