Dynamic Ultrasound Evaluation of the Upper Limb Musculoskeletal Disorders

Abstract

Summary and Conclusion O ne of the most important diagnostic advantages of sonography over other techniques is its real-time imaging capability, allowing for dynamic evaluation. Dynamic sonography is of particular interest because some disorders of muscles, tendons and joints are better seen using real-time imaging during motion of the extremity, muscle contraction, probe compression, or position change of the patient. Dynamic sonography of the shoulder must be regarded as a subacromial impingement imaging test that can be easily integrated into a routine sonography shoulder examination protocol, providing useful information to the clinician. In shoulder joint imaging, dynamic sonography can provide direct visualization of the relationships between the anterior one third of the acromion, subacromial bursa, supraspinatus tendon, and greater tuberosity of the humeral head during active shoulder motion. It can also show which structure is being impinged and can show upward migration of the humeral head, thus providing valuable information about the potential intrinsic and extrinsic causes of the subacromial impingement syndrome. A wider range of abnormalities can be observed on dynamic sonography in the presence of subacromial impingement. Using dynamic sonography, described pooling of fluid lateral to the subdeltoid bursa as signs of early-stage subacromial impingement. Dynamic sonography of the elbow was used to aid in the accurate diagnosis of, and differentiation between, ulnar nerve dislocation and snapping of the medial triceps muscle. Causes of medial elbow pain and/or ulnar neuropathy are many, and they include ulnar nerve compression within the cubital tunnel, ulnar nerve subluxation or dislocation, and snapping triceps syndrome. The dynamic imaging allows continual visualization of the ulnar nerve and triceps muscle throughout active elbow flexion and extension. Knowledge and accurate diagnosis of ulnar nerve and/or medial triceps muscle dislocation as causes for medial elbow snapping are important so that proper surgical treatment may be prescribed.