Synovial abnormalities are detectable using ultrasound imaging, and researchers are now recommending the imaging technology’s use as an adjuvant for managing patients with knee pain during diagnostic strategy and individualized treatment decision-making, according to a study published in Arthritis Care and Research.
Researchers performed a meta-analysis that included studies assessing patients with knee pain, using both ultrasound and MRI to assess synovial abnormalities, evaluating the accuracy of ultrasound based on MRI as the reference standard or investigating correlations between ultrasound and MRI, and no language and study design restrictions.
The study aimed to compare the diagnostic accuracy of ultrasound and MRI in evaluating synovial abnormalities and the correlation between the 2 in patients with knee pain. The meta-analysis evaluated 14 studies involving 755 patients and 918 knees. The mean age of participants was 46.3 years, and 51.3% were women.
The area under the curve (AUC) in 6 studies that evaluated 199 knees was 0.81 (95% CI, 0.77-0.84) with a DOR of 16.91 (95% CI, 4.68-61.12), which indicates a good diagnostic accuracy when ultrasound was used for knee synovitis in patients with knee pain. Further analyses showed excellent diagnostic accuracy for knee pain when ultrasound was used. A strong positive correlation between ultrasound-based and MRI-based synovitis was demonstrated in 5 studies representing 242 knees.
The pooled Spearman correlation coefficient of these studies was 0.64 (95% CI, 0.56-0.71). Analysis of 2 additional studies and 128 knees also demonstrated a strong correlation.
“Overall, this meta-analysis implies that ultrasound is a valid approach for assessing synovitis and synovial effusion among patients with knee pain,” the researchers report. “Given that ultrasound is a more widely available, cost-effective and real-time imaging, it is therefore recommended as an adjuvant especially for etiological diagnosis and individualized management among patients with knee pain.”
Study limitations include a non-generalizable study population due to most enrolled patients having chronic knee pain, a lack of cut-off due to limited data extraction, and a limited number of original articles resulting in an inability to perform a subgroup analysis based on different causes of knee pain.
Liu K, Li X, Weng Q, et al. Diagnostic accuracy of ultrasound for assessment of synovial abnormalities among patients with knee pain: a meta-analysis. Arthritis Care Res (Hoboken). Published online July 31, 2023. doi:10.1002/acr.25205