Dr. Costouros specializes in the comprehensive treatment of shoulder disorders with both arthroscopic and open techniques. He is Board-Certified by the American Board of Orthopaedic Surgeons and has a Certificate of Added Qualification (CAQ) in Sports Medicine. He has particular expertise in traditional and reverse shoulder replacements, rotator cuff repair, fractures and sports injuries of the shoulder.

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), and the European Shoulder and Elbow Society (SECEC). 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.