Ultrasound-Guided Biceps-Tracking Access to the Superior Labral-Biceps Anchor Complex: A Technical Report With Cadaveric Demonstration of Gross Injectate Localization.

The superior labral-biceps anchor complex is a technically difficult ultrasound target because of its deep location, close relationship to the glenohumeral joint, and partial obscuration by adjacent osseous structures. In current practice, image-guided injections for suspected superior labral pathology are generally performed as glenohumeral intra-articular injections rather than as footprint-directed procedures. This technical report describes a structured ultrasound-guided biceps-tracking approach to the superior labral-biceps anchor complex and provides a cadaveric demonstration of gross injectate localization. A single fresh-frozen male cadaver was studied bilaterally. The long head of the biceps tendon was identified in short axis within the bicipital groove and then sequentially tracked proximally through the rotator interval to its intra-articular origin. Under real-time ultrasound guidance, a 23-gauge, 6-cm needle was advanced using an out-of-plane lateral-to-medial trajectory, and 1 mL of red-stained high-viscosity filler was injected at the intended target in each shoulder. Layer-by-layer dissection was performed approximately one hour later to assess gross filler localization. In both shoulders, dissection demonstrated focal filler localization at the supraglenoid tubercle/biceps anchor region, with gross injectate localization adjacent to the intended footprint on direct inspection. No diffuse red-filler pooling was observed within the glenohumeral joint cavity, and no gross posterior, medial, or anterior extension beyond the supraglenoid tubercle was identified. A consistent technical limitation was the narrow acoustic and spatial window between the coracoid process and clavicle. Interpretation of these findings should be cautious because localization was assessed by gross anatomical evaluation only, and the injectate was a high-viscosity surrogate material whose dispersion characteristics may differ from those of clinically used injectates. These findings suggest preliminary anatomical feasibility of ultrasound-guided footprint-level access to the superior labral-biceps anchor complex in this cadaveric specimen. Because this report is based on a single cadaver with bilateral non-independent observations, gross assessment only, and a non-clinical surrogate injectate, the findings should be interpreted as descriptive rather than as evidence of reproducibility, safety, procedural accuracy, or clinical efficacy.