Dr. Costouros specializes in the comprehensive treatment of shoulder disorders using both arthroscopic and open surgical techniques. He is Board-Certified by the American Board of Orthopedic Surgery, a Fellow of the American Academy of Orthopaedic Surgeons and the American College of Surgeons, and has a Certificate of Added Qualification (CAQ) in Sports Medicine. He has particular expertise in traditional and reverse shoulder replacements, stemless shoulder arthroplasty, rotator cuff repair, the treatment of shoulder instability, revision shoulder surgery, and the treatment of sports injuries and fractures of the clavicle and shoulder girdle. He has developed innovative techniques and devices which are FDA-approved and in clinical use worldwide. He is Past President of the Northern California Orthopaedic Society, Northern California Chapter of the Western Orthopaedic Association, and the Leroy C. Abbott Orthopaedic Society. He is an active member of the society of American Shoulder and Elbow Surgeons (ASES), American Academy of Orthopaedic Surgeons (AAOS), Arthroscopy Association of North America (AANA), European Shoulder and Elbow Society (SECEC), and International Society of Arthroscopy, Knee Surgery, and Sports Medicine (ISAKOS). His research is focused on enhancing clinical outcomes using molecular mediators, stem cells, biologics, and the design of state-of-the-art implants used in shoulder surgery.