C. Benjamin Ma, MD

Chief of Sports Medicine and Shoulder Surgery

Dr. C. Benjamin Ma is chief of sports medicine and shoulder surgery. He specializes in shoulder surgery, with expertise in all procedures including arthroscopy, replacements and tendon transfers. He also specializes in arthroscopic knee surgeries, such as ligament reconstruction, cartilage replacement and meniscus surgery.

Ma's research focuses on advanced imaging of cartilage degeneration, anterior cruciate ligament (ACL) reconstructions and rotator cuff repairs. He has received multiple research grants, from such organizations as the National Institutes of Health and the Arthritis Foundation, for rotator cuff studies and advanced imaging of ACLs and cartilage. He is involved in clinical trials of shoulder replacements, cartilage resurfacing and interventions to prevent knee osteoarthritis.

Ma earned his medical degree at Johns Hopkins University. He completed a residency in orthopedic surgery at the University of Pittsburgh, where he also completed a fellowship in musculoskeletal research. He then completed a fellowship in shoulder and knee surgery and sports medicine at the Hospital for Special Surgery.p>

Ma is a member of the MOON Shoulder Group, a professional collaboration within the Multicenter Orthopaedic Outcomes Network. He is also a member of the American Orthopaedic Society for Sports Medicine, Arthroscopy Association of North America, International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine, and American Shoulder and Elbow Society. He is a professor of orthopedic surgery at UCSF.


Arthritis and Joint Replacement Center
1500 Owens St., Suite 430
San Francisco, CA 94158
Phone: (415) 353–2808
Fax: (415) 885–3862

Hours: Monday to Friday, 8 a.m. – 5 p.m.

Cartilage Repair and Regeneration Center
1500 Owens St.
San Francisco, CA 94158
Phone: (415) 353–7566

Hours: Monday to Friday, 8 a.m. – 5 p.m.

Sports Medicine Center
1500 Owens St.
San Francisco, CA 94158
Appointments: (415) 353–2808
Main: (415) 353–9400
Fax: (415) 885–3862

Hours: Monday to Friday, 8 a.m. – 5 p.m.

Conditions & Treatments

Board Certification

Orthopaedic Sports Medicine, American Board of Orthopaedic Surgery
Orthopaedic Surgery, American Board of Orthopaedic Surgery

Academic Title


More about C. Benjamin Ma


John Hopkins University School of Medicine 1996


University of Pittsburgh Medical Center, Orthopedic Surgery 2002


University of Pittsburgh Medical Center, Musculoskeletal Research 2002
Hospital for Special Surgery, New York, Shoulder and Knee Surgery/Sports Medicine 2003

Selected Research and Publications

  1. Ma CB. Editorial Commentary: Biomechanics of Cutting Studies-Knowledge and Deficiencies: Knee Joint Stability and the Posterolateral Corner. Arthroscopy. 2017 Oct; 33(10):1831.
  2. Lansdown DA, Pedoia V, Zaid M, Amano K, Souza RB, Li X, Ma CB. Variations in Knee Kinematics After ACL Injury and After Reconstruction Are Correlated With Bone Shape Differences. Clin Orthop Relat Res. 2017 Oct; 475(10):2427-2435.
  3. Wong SE, Pitcher AA, Ding DY, Cashman N, Zhang AL, Ma CB, Feeley BT. The effect of patient gender on outcomes after reverse total shoulder arthroplasty. J Shoulder Elbow Surg. 2017 Nov; 26(11):1889-1896.

Publications are derived from MEDLINE/PubMed and provided by UCSF Profiles, a service of the Clinical & Translational Science Institute (CTSI) at UCSF. Researchers can make corrections and additions to their publications by logging on to UCSF Profiles.