The role of sonography in differentiating full versus partial distal biceps tendon tears: correlation with surgical findings.

OBJECTIVE: The purpose of this study was to determine the accuracy of ultrasound for distinguishing complete rupture of the distal biceps tendon versus partial tear and versus a normal biceps tendon. Surgical findings were used as the reference standard in cases of tear. Clinical follow-up was used to assess the normal tendons. MATERIALS AND METHODS: The study population consisted of 45 consecutive elbow ultrasound cases with surgical confirmation and six cases of a clinically normal distal biceps tendon that underwent elbow ultrasound for suspicion of injury to a structure other than the biceps tendon. Cases underwent consensus review by two fellowship-trained musculoskeletal radiologists. Tendons were classified as normal biceps tendon, partial tear, or complete tear. The presence or absence of posterior acoustic shadowing at the distal biceps tendon was also assessed. The ultrasound findings were then compared with the surgical findings and clinical follow-up. RESULTS: Ultrasound showed 95% sensitivity, 71% specificity, and 91% accuracy for the diagnosis of complete versus partial distal biceps tendon tears. Posterior acoustic shadowing at the distal biceps had sensitivity of 97% and accuracy of 91% for indicating complete tear versus partial tear and sensitivity of 97%, specificity of 100%, and accuracy of 98% for indicating complete tear versus normal tendon. CONCLUSION: Ultrasound can play a role in the diagnosis of elbow injuries when a distal biceps brachii tendon tear is suspected.

Entrapment neuropathies I: upper limb (carpal tunnel excluded).

Several entrapment neuropathies of the upper extremity can cause hypoechoic swelling and nerve compression as seen at ultrasound. The ulnar nerve can be compressed at the cubital tunnel of the elbow and Guyon's canal at the wrist. The deep branch of the radial nerve can be compressed at the supinator muscle at the elbow, and the superficial radial nerve may be compressed at the dorsal wrist (Wartenberg's syndrome). In addition to compression at the carpal tunnel, the median nerve may be compressed at the elbow, related to a supracondylar process or by the pronator teres. Knowledge of these key anatomical sites of potential nerve compression is essential for accurate diagnosis of entrapment neuropathies.