Abstract
Background: Anterior knee pain (AKP) is a problematic complaint, considered to be the most frequent cause of
orthopedic consultancy for knee problems. This study aimed to highlight diagnostic accuracy of ultrasonography as
a fast imaging technique in assessment of patients with AKP.
Methods and results: A prospective study was conducted on 143 patients with clinically confirmed AKP. All
patients underwent ultrasonography and MRI examinations of the knee. The diagnostic accuracy of
ultrasonography compared to MRI for evaluating different findings of possible causes of AKP were analyzed
using receiver operating characteristic (ROC) curve and judged by area under curve (AUC). A total of 155
knees were included in the study; 26 knees showed no abnormalities, 19 knees showed positive MRI only,
and 110 knees showed positive ultrasonography and MRI. Ultrasonography and MRI reported 11 different
findings of possible causes of AKP or related to it. Joint effusion was the most common finding (38%)
followed by trochlear cartilage defect (20.6%) and superficial infrapatellar subcutaneous edema (20%). The
overall accuracy of ultrasonography was 85.3% sensitivity and 100% specificity. The ultrasonography provided
the highest sensitivity (100%) in detecting bipartite patella, followed by 91.5% for joint effusion, and 87.5% for
quadriceps tendinopathy. The ROC curve analysis of overall accuracy of ultrasonography showed an AUC of
0.93. The overall Kappa agreement between ultrasonography and MRI was good (k = 0.66).
Conclusion: Ultrasonography can be used to make a swift screening and assessment of painful anterior knee
and as an alternative to MRI when it is unavailable or contraindicated.
Keywords: Knee joint, Ultrasonography, Magnetic resonance imaging, Anterior knee pain, Diagnostic accuracy |
