[Fracture sequelae type 2 of the proximal humerus-clinical results after arthroplasty].

Locked dislocations of the glenohumeral joint are rare but often painful and are associated with limited range of motion in the shoulder. In patients of advanced age, arthroplasty is increasingly indicated as a surgical treatment option. Preoperatively, the direction of dislocation, the presence and extent of a glenoid defect, and the soft tissue situation (rotator cuff status, joint capsule) should be analyzed in a differentiated manner. Based on the above factors, we recommend the subclassification of type 2 according to Boileau: posterior locked dislocation (2a), anterior locked dislocation without glenoid defect (2b), and anterior locked dislocation with glenoid defect (2c). In the case of dorsally locked dislocation, a good clinical result can be achieved by using an anatomical endoprosthesis. For ventrally locked dislocations, we recommend using an inverse total endoprosthesis with, if necessary, bony glenoid reconstruction and transfer of the pectoralis major muscle.Level of evidence: IV.