High Diagnostic Accuracy of Ultrasonography for Supraspinatus Tears in a Pakistani Tertiary Center: A Cost-Effective Alternative to MRI

Abstract

Background: Shoulder pain, the most prevalent cause of musculoskeletal disorders worldwide, is usually due to tears of the supraspinatus tendon, comprising 65–70% of rotator cuff disease. MRI is the gold standard for diagnosis; however, its high cost (PKR 20–30k per scan), limited availability in rural areas, and contraindications restrict its use in low-resource regions. Ultrasonography (USG) offers a potential substitute, but there is a need for regionally oriented validation studies in clinically heterogeneous populations. Objective: To evaluate the diagnostic accuracy of high-resolution ultrasonography for supraspinatus tendon tears compared to MRI in a tertiary care setting with limited MRI access. Methods: A cross-sectional survey was conducted on 85 patients (mean age: 52.3 ± 12.7 years; 61.2% male) between 2022–2023 at Combined Military Hospital Abbottabad. Ultrasound examinations (10–15 MHz linear transducer) and 1.5T MRI were performed in a standardized manner for all participants. Images were independently analyzed by two blinded radiologists. Diagnostic accuracy metrics (sensitivity, specificity, PPV, NPV) were calculated using MRI as the reference standard. Cohen's kappa (κ) was used to assess inter-rater reliability. Results: Ultrasonography showed 94% sensitivity (95% CI: 86.5%–97.8%) and 94.29% specificity (95% CI: 85.1%–98.2%), with a PPV of 95.92% and NPV of 91.67%. Inter-rater agreement was very good (κ = 0.89). Subgroup analysis revealed 89.5% sensitivity for partial-thickness tears and 97.1% for full-thickness tears. Conclusion: The diagnostic performance of high-resolution ultrasonography is nearly equivalent to MRI for detecting supraspinatus tendon tears, particularly for full-thickness tears. Its cost-effectiveness (approximately $3–$4 per study), portability, and real-time imaging capabilities make it an ideal first-line diagnostic tool in low-resource settings, potentially reducing MRI referrals by approximately 60–70%. These findings may inform global healthcare practices by supporting the development of musculoskeletal ultrasonography training programs to address disparities in shoulder care.