Abstract: Objective    To provide anatomical basis for the treatment of scapulohumeral periarthritis using the local steroid injection.  Methods  The literature of the injection method for the treatment of scapulohumeral periarthritis by the local steroid injection were reviewed. The geometric relationship between the bone location markers and the lesion site was investigated by using 30 shoulder of three-dimensional models, and an improved method of local steroid injection was obtained. A modified method was used to perform closed injection on 34 antiseptic cadaver specimens, and the accuracy of the injection was verified by anatomy.   Results   1. The geometric relationship analysis showed that the needle was inserted into the anterior corner of the acromion, and the No.7 needle was fan-shaped, and the needle could reach almost the entire subacromial space. At the midpoint of the line between the apex of coracoid process and anterior corner of the acromion, the needle may be inserted into the joint cavity towards the humerus head. 2. Anatomically, it was found that there was a certain gap between the biceps brachii tendon and the anterior edge of greater tubercle, which could be the point of needle entry. 3. The accuracy of the improved injection method was 100%.   Conclusions   Familiarity with the geometric relationship and anatomical characteristics of the shoulder is helpful to improve the feasibility and accuracy of local steroid injection.

Key words: Scapulohumeral periarthritis,  ,  , Frozen shoulder,  ,  , Local steroid injection,  ,  , Anatomy