The Accuracy of Ultrasonography in the Diagnosis of Ligamentous and Meniscal Injuries of the Knee among Patients Attending Muhimbili Orthopaedic Institute (MOI)

Background Ligamentous and meniscal knee injuries are among the most common conditions managed at MOI and represent a significant burden primarily among the young adult population. Magnetic resonance imaging (MRI) has served as the key diagnostic investigation and basis for management decisions, yet it is expensive and less available in peripheral hospitals. Ultrasonography, which is readily available and affordable, remains underutilised and sonographic patterns of knee trauma in our setting are poorly described. Expanded use of ultrasonography could reduce the number of unnecessary referrals and lower treatment costs. Methods This was a prospective descriptive hospital-based cross-sectional study involving 100 consecutive patients with clinically suspected ligamentous and/or meniscal knee injuries referred for MRI at MOI between December 2022 and March 2023. All participants underwent standardised knee ultrasonography before MRI. A structured checklist captured sociodemographic data, clinical presentations, and imaging features. Statistical analysis was performed using SPSS version 23. Descriptive statistics were used for categorical and continuous variables. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy (DA) of ultrasonography were calculated against MRI as the reference standard using 2×2 contingency tables. A p-value < 0.05 was considered statistically significant. Results The study included 100 participants with a mean age of 43.88 years (SD ± 13.9); the majority (46%) fell within the 31–50 age group. Gender distribution was nearly equal (52% male). The most common mechanism of injury was falling (45%), followed by sports activities (33%). Medial meniscal injury was most prevalent (57%), followed by lateral meniscal injury (43%). The most frequent ultrasonographic feature was loss of uniform echopattern throughout the meniscus (68% for MM injuries). The sensitivity, specificity, and diagnostic accuracy of ultrasonography were: medial meniscus 90.5%, 70.3%, 83%; lateral meniscus 71.7%, 87.5%, 78%; medial collateral ligament 25%, 100%, 97%; lateral collateral ligament 0%, 100%, 99%; anterior cruciate ligament 14.3%, 100%, 82%; and posterior cruciate ligament 20%, 100%, 96%, respectively. Conclusions Ultrasonography demonstrated significant diagnostic agreement with MRI for medial and lateral meniscal injuries, with high sensitivity and specificity. High specificity (100%) was observed for all ligamentous injuries, though sensitivity was limited for collateral and cruciate ligaments, likely due to small sample sizes. Ultrasonography shows promise as a cost-effective, accessible first-line or adjunct imaging tool for knee injury assessment in resource-limited settings.