The Application Of Trans-coracoacromial Ligament Glenohumeral Injection Technique In Primary Frozen Shoulder

Purpose: The purposes of this study were to describe a transcoracoacromial ligament glenohumeral injection technique that did not require radiographic guidance,and to explore the accuracy of this injection technique in patients with idiopathic adhesive capsulitis.Methods: From February 2015 to April 2017,89 consecutive patients(116 injections)with idiopathic adhesive capsulitis were included in the study.All of them received unguided glenohumeral injection via transcoracoacromial ligament technique,and post-procedural fluoroscopic images were used to determine accuracy.The anterolateral corner of acromion(ACA),the superior lateral border of coracoid tip(SLBCT)and the curved depression of distal clavicle(CDDC)were identified.The needle entry site was located at the trisection point between the distal third and middle third of the SLBCT-CDDC line;needle trajectory was perpendicular to the plane formed by the three points,and needle was advanced towards the humeral head.An injection was rated as a success if first fluoroscopic picture showed intraarticular contrast;it was rated as a failure if contrast was not intraarticular or the needle needed to be redirected more than 2 times.Results: Out of 116 injections,111(95.7%)were successful.For five failed injections,there was one shoulder with more than two redirections,and four shoulders with no intra-articular contrast(the needle hit the coracoid process in one shoulder,the needle rested in anterior glenoid labrum in two shoulders and the needle was inserted into subscapularis in one shoulder).Conclusions: The trans-coracoacromial ligament glenohumeral injection technique was highly accurate and reproducible in patients with idiopathic adhesive capsulitis.The precise location of related anatomic landmarks and insertion site,as well as the standardized injection procedure,all contribute to the highly reproducible technique.