Initial experiences with a new MRI scoring system for differentiating advanced femoral osteonecrosis from tubercular
Abstract:
The purpose of this study was to formulate a magnetic resonance imaging-based scoring system for differentiating tuberculous arthritis from advanced osteonecrosis of the femoral head. Magnetic resonance imaging findings in 18 hips with tuberculous arthritis and 36 hips with advanced osteonecrosis of the femoral head were reviewed retrospectively. Confirmation of tuberculous arthritis was based on enzyme-linked immunosorbent assay and/or synovial biopsy. Osteonecrosis was confirmed either by histopathology or eventual radiographic evidence on follow-up. The findings were analyzed with an emphasis on the changes in femoral head marrow, joint cavity, synovium, acetabulum, and contrast enhancement patterns. A score of 2 was assigned for the presence of each of the following: T2 hyperintensity of the femoral head, synovial hypertrophy, articular cartilage erosion, unilateral involvement of the femoral head, acetabular edema/sclerosis, and enhancement of the involved head. A score of 1 was assigned for each of the following: joint effusion, edema of adjacent marrow, and enhancement of adjacent soft tissue. A cutoff value of 10 of 15 points was considered to be positive for tuberculous arthritis. Sixteen of 18 cases of tuberculous arthritis were correctly identifiable on the basis of this scoring system. The 2 remaining cases had a score of 9. No case of osteonecrosis of the femoral head scored more than 9. A score of 10 for a positive diagnosis of tuberculous arthritis had a sensitivity of 88.89% and specificity of 100%. Positive and negative predictive values were 1 and 0.94, respectively. Statistical significance for each of the parameters and the entire model was established with logistic regression analysis. This new scoring system is effective in solving the imaging dilemma pertinent to endemic regions.
Insights
This study developed a magnetic resonance imaging (MRI) scoring system to distinguish tuberculous arthritis from osteonecrosis of the femoral head. The new MRI scoring system effectively differentiates these conditions, aiding diagnosis in endemic areas.
Area of Science:
- Orthopedics
- Radiology
- Infectious Diseases
Background:
- Differentiating tuberculous arthritis from osteonecrosis of the femoral head can be challenging using imaging alone.
- Advanced osteonecrosis and tuberculous arthritis share some overlapping magnetic resonance imaging (MRI) features.
- Accurate diagnosis is crucial for appropriate treatment and patient outcomes.
Purpose of the Study:
- To formulate and validate a novel MRI-based scoring system for distinguishing tuberculous arthritis from advanced osteonecrosis of the femoral head.
- To improve diagnostic accuracy in regions where tuberculous arthritis is endemic.
Main Methods:
- Retrospective review of MRI findings in 18 hips with tuberculous arthritis and 36 hips with advanced osteonecrosis of the femoral head.
- Analysis of specific MRI features including femoral head marrow changes, joint cavity, synovium, acetabulum, and contrast enhancement patterns.
- Development of a scoring system assigning points to key imaging findings, with a cutoff value for diagnosis.
Main Results:
- The developed MRI scoring system demonstrated high accuracy in differentiating the two conditions.
- A cutoff score of 10 out of 15 points correctly identified 16 of 18 tuberculous arthritis cases.
- The system achieved 88.89% sensitivity and 100% specificity for tuberculous arthritis, with no osteonecrosis cases scoring above 9.
Conclusions:
- The novel MRI-based scoring system is effective in differentiating tuberculous arthritis from advanced osteonecrosis of the femoral head.
- This tool addresses a significant diagnostic challenge, particularly in endemic geographical areas.
- The scoring system offers a reliable method for improving diagnostic confidence in distinguishing these hip pathologies.
