Accuracy of the biceps tendon sheath injection: ultrasound-guided or unguided injection? A randomized controlled trial

Background: Patients often localize pain in the anterior shoulder; however, this patient-localized pain does not necessarily correlate to the location of disease. Unguided shoulder injections are common in clinical practice. The accuracy of unguided biceps tendon sheath injections has not been studied. Patient management may be aided by the knowledge of injection accuracy. This study compared the accuracy of ultrasound-guided biceps tendon sheath injection with unguided injection. Materials and methods: The study comprised 30 patients (30 shoulders) with reported anterior shoulder pain who had a primary diagnosis of tenosynovitis or tendinitis of the biceps tendon, or both. Shoulders were randomly allocated into ultrasound-guided and unguided injection groups. Computed tomography (CT) imaging was performed immediately after a contrast agent was injected into the biceps tendon sheath. The locations of contrast seen on CT scan were classified into 3 types: only within the tendon sheath (type 1); inside the tendon, tendon sheath, and surrounding area (type 2); and only the area outside the tendon sheath (type 3). Results: Ultrasound-guided injections resulted in 86.7% type 1 and 13.3% type 2 locations. Unguided injections resulted in 26.7% type 1, 40.0% type 2, and 33.3% type 3 locations. The difference for each location type was significant (P < .05). Conclusion: Injection into the tendon sheath of the long head of the biceps brachii can be more accurately performed using ultrasound guidance than by the blind method. Level of evidence: Level II, Randomized Controlled Trial, Treatment Study. (C) 2011 Journal of Shoulder and Elbow Surgery Board of Trustees.