NGHIÊN CỨU GIÁ TRỊ CỦA SIÊU ÂM ĐO ĐỘ DÀY BAO KHỚP VÙNG HỐ NÁCH TRONG CHẨN ĐOÁN ĐÔNG CỨNG KHỚP VAI CÓ ĐỐI CHIẾU VỚI CỘNG HƯỞNG TỪ

Abstract

Background: Frozen shoulder is a common clinical condition, typically diagnosed based on clinical findings and magnetic resonance imaging. However, the diagnostic value of ultrasound has not been clearly established. Objective: To determine the value of ultrasound in measuring the thickness of the axillary recess capsule in the diagnosis of frozen shoulder. Materials and Methods: A prospective study was conducted on 50 patients with clinically diagnosed unilateral frozen shoulder at Vinmec Times City International Hospital, from January 2023 to May 2025. The thickness of the axillary recess capsule was measured by ultrasound on both shoulders; the affected shoulder was also assessed by magnetic resonance imaging (MRI) for comparison. Results: The mean axillary recess capsule thickness measured by ultrasound was 4.3 ± 1.1 mm on the affected side and 2.1 ± 0.5 mm on the unaffected side. On MRI, the mean thickness on the affected side was 8.8 ± 1.8 mm. The optimal diagnostic threshold for ultrasound was 3.0 mm, with a sensitivity of 82%, specificity of 94%, positive predictive value (PPV) of 93%, and negative predictive value (NPV) of 84%. Conclusion: Ultrasound enables accurate evaluation of axillary recess capsule thickness in frozen shoulder and shows strong correlation with MRI findings. An axillary recess capsule thickness ≥ 3 mm on ultrasound demonstrates high diagnostic performance and may serve as a potential alternative to MRI in clinical practice.