Accuracy of Two Ultrasound-Guided Coracohumeral Ligament Injection Approaches: A Cadaveric Study

Background Glenohumeral idiopathic adhesive capsulitis is a common shoulder condition that hinders functionality. Addressing the pathology has been extensively researched. Ultrasound (US)-guided injections have shown their efficacy. However, no study has been conducted to compare anatomical accuracy between different approaches in targeting the coracohumeral ligament (CHL). Objective To investigate whether US-guided injection of the CHL can be performed accurately using either the rotator interval (RI) or the coracoidal (CO) approach. Methods An experimental cadaveric case series. Setting Anatomy laboratory. Specimens Both shoulders of 13 Thiel-embalmed cadavers. Interventions Three physiatrists each injected a 0.1 mL bolus of colored dye in both shoulders of each cadaver using either the RI or the CO approach under US guidance. Each cadaver received a total of six injections (three injections per shoulder). The accuracy of the injection was determined following shoulder dissection by an anatomist. Main Outcome Measure The accuracy of the US-guided injection of the CHL. Results The RI approach yielded 36 accurate injections, giving it an accuracy of 100%. With the CO approach two injections were deemed inaccurate yielding an accuracy of 94%. There was no significant difference in accuracy between all operators. Conclusions US-guided injection of the CHL can be performed accurately with both the RI and CO approaches. The RI approach was likely to be more accurate.