Case: A 77-year-old man with an acromioclavicular joint ganglion cyst with cuff tear arthropathy had a large mass in the left shoulder. Arthroscopic distal clavicle resection successfully relieved his symptoms without loss of shoulder function by enlargement of the bypass between the cyst and subacromial space through the acromioclavicular joint. Conclusion:Arthroscopic distal clavicle resection can remove a 1-way check valve in a minimally invasive manner. This case indicated that arthroscopic distal clavicle resection could be a useful treatment option for patients with acromioclavicular joint ganglion cysts with functional but irreparable rotator cuff tears. Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article (http://links.lww.com/JBJSCC/B834).

Case: A 60-year-old woman with avascular necrosis of the right humeral head underwent anatomical total shoulder arthroplasty (TSA); however, recurrent posterior dislocation occurred 13 months postoperatively. We performed bone block grafting of an autologous iliac crest to the posterior glenoid and posterior capsular plication, after which satisfactory postoperative shoulder function without residual joint instability was achieved. Conclusion:The presented case had recurrent posterior dislocation after TSA without any abnormal findings in the prosthetic components. Posterior bone block grafting with capsular plication should be considered a viable option for posterior instability after anatomical TSA.Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article (http://links.lww.com/JBJSCC/B815).