*6.1. Nonoperative Treatment*

Non-operative treatment of shoulder dislocation arthropathy should be the first step of management. Classic studies have shown similar OA proportions between non-operative and operative treatment at any point of follow up [35]. There is no evidence of significant benefit in using non-steroidal anti-inflammatory drugs (oral or topic) to treat shoulder pain. Improvements could be found with oral prednisolone, but side effects should be taken into special consideration when using these medications. Intraarticular corticosteroids or hyaluronic acid are among the most popular nonoperative treatments for glenohumeral OA. While both have demonstrated sustained pain relief, difficulty in accurately adminis-

tering them in the glenohumeral joint without ultrasound assistance has been pointed out. There are no efficacy studies regarding physical therapy as an isolated treatment. Several multimodal therapy plans have proven sustained improvements in pain and function [56].

#### *6.2. Removal of Foreign Material*

Metal anchors that contact the joint surface will lead to a progressive OA in the shortest time. Pain or crepitation after shoulder stabilization should, therefore, be clarified. The positions of possible metal anchors can be retraced in a thin slice CT. Without the slightest doubt, a revision arthroscopy and the removal of the anchors are necessary. The knowledge of the kind of brought-in anchors is vital to providing the right removal instrument. To approach the anchor in its centerline, percutaneous instrumenting can be helpful. Metal portions that are not visible in the joint at first sight could be covered by only a thin layer of soft tissue and should, therefore, be removed.

Implants for shoulder stabilization have evolved to suture anchors manufactured of various materials, including metal, poly-L-lactic acid, PEEK (polyether ether ketone), and all sutures. "Anchor arthropathy" could be defined as an own entity after stabilization surgery. Early-onset of pain and stiffness, usually before 10 months after index surgery, could be found. Waltz et al. found advanced imaging, such as MRI unreliable to confirm proud implants or prominent suture knots. Therefore, early arthroscopy to assess painful and stiff shoulders after instability repair should have a low threshold [57].

#### *6.3. Arthroscopic Debridement and Arthrolysis*

In the case of an early stage of OA arthroscopic, debridement with loose cartilage portions removal and partial synovectomy can improve functionality and relieve pain. The cause of arthritis, e.g., the eccentric load of the glenoid as its "engine", is not resolved by this. An arthroscopic debridement can only help if a sufficient passive range of motion with the possibility of relieving after treatment is present. Removing the osteophytes, usually within the front lower range of the anatomical neck, is technically challenging. Millet's CAM procedure was developed as a joint-preserving arthroscopic treatment approach for young, active patients with advanced shoulder OA [58]. Besides chondroplasty, synovectomy, loose body removal, and subacromial decompression, the CAM procedure also involves extensive capsular release to restore motion, humeral osteoplasty, and osteophyte excision to recontour the humeral head, restore abduction, and potentially decompress impingement on the axillary nerve; axillary nerve neurolysis when scarring is seen and biceps tenodesis when there is significant tenosynovitis, SLAP tear or a pulley lesion [59]. Arner et al. reported significant improvements in 38 patients after 10 years of follow-up of the CAM procedure. Humeral head flattening and severe joint incongruity were risk factors for CAM failure, although survivorship was 63% at a minimum 10-year follow-up [60]. A recent investigation from the same group found similar results after arthroplasty, whether a prior CAM procedure was performed before the prosthesis [61].
