**7. Conclusions**

Dislocation arthropathy can be the consequence of an instability episode of the shoulder. The risk of developing OA after primary traumatic dislocation compared to the normal situation is increased up to 10–20-fold. The age at the initial dislocation, bony lesions at the glenoid, and the head or a rotator cuff tear increase the risk. The classification according to Samilson and Prieto is used. CT and MR tomographic diagnostics increase the genesis statement, the classification, and the therapeutic options. Rates of OA after stabilization range between 12 and 62%, whereby a safe designation of the operational procedures cannot be made. The Latarjet procedure seems to have a lower degree of OA than other treatments, even conservative treatments. Metal anchors and screws with joint contact lead to a rapidly progressive OA and must be removed, arthroscopically. In low-grade OA, arthroscopic

debridement is helpful. Arthroscopic arthrolysis with capsulotomy can improve elevation and external rotation in cases of internal rotation contracture. If massive OA is present, prosthesis becomes inevitable. However, patients with instability arthropathy are mostly younger and suffer from a considerable internal rotation deficit and glenoid defects. The defect size determines the humeral replacement. Using Cup-prostheses, it should not exceed 30%. Results of total shoulder prosthesis are superior to those of hemiarthroplasty. Three-dimensional planning tools are becoming useful for correct implant selection. Results of RSA are promising; however, a longer follow-up is required. Significant glenoid defects need to be treated with bone grafting to provide stability. Nevertheless, bone grafting increases the risk of implant failure. The type of primary treatment and external rotation did not affect the prognosis of the prosthesis after glenohumeral stabilization, whereas fatty degeneration of the rotator cuff did.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Conflicts of Interest:** Ulrich H. Brunner and Markus Scheibel are consultant for Stryker.
