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.
  4. Ma CB. Editorial Commentary: Success of Rotator Cuff Healing-Do We Need to Improve on the Strength Anymore? Arthroscopy. 2017 Sep; 33(9):1659-1660.
  5. Cheah JW, Sing DC, McLaughlin D, Feeley BT, Ma CB, Zhang AL. The perioperative effects of chronic preoperative opioid use on shoulder arthroplasty outcomes. J Shoulder Elbow Surg. 2017 Nov; 26(11):1908-1914.
  6. Lansdown DA, Lee S, Sam C, Krug R, Feeley BT, Ma CB. A Prospective, Quantitative Evaluation of Fatty Infiltration Before and After Rotator Cuff Repair. Orthop J Sports Med. 2017 Jul; 5(7):2325967117718537.
  7. Surgical Predictors of Clinical Outcomes After Revision Anterior Cruciate Ligament Reconstruction. Am J Sports Med. 2017 Sep; 45(11):2586-2594.
  8. Azus A, Teng HL, Tufts L, Wu D, Ma CB, Souza RB, Li X. Biomechanical Factors Associated With Pain and Symptoms Following Anterior Cruciate Ligament Injury and Reconstruction. PM R. 2018 Jan; 10(1):56-63.
  9. Subsequent Surgery After Revision Anterior Cruciate Ligament Reconstruction: Rates and Risk Factors From a Multicenter Cohort. Am J Sports Med. 2017 Jul; 45(9):2068-2076.
  10. Samaan MA, Facchetti L, Pedoia V, Tanaka MS, Link TM, Souza RB, Ma CB, Li X. Cyclops lesions are associated with altered gait patterns and medial knee joint cartilage degeneration at 1 year after ACL-reconstruction. J Orthop Res. 2017 10; 35(10):2275-2281.
  11. Amano K, Li AK, Pedoia V, Koff MF, Krych AJ, Link TM, Potter H, Rodeo S, Li X, Ma CB, Majumdar S. Effects of Surgical Factors on Cartilage Can Be Detected Using Quantitative Magnetic Resonance Imaging After Anterior Cruciate Ligament Reconstruction. Am J Sports Med. 2017 Apr; 45(5):1075-1084.
  12. Aleem AW, Feeley BT, Austin LS, Ma CB, Krupp RJ, Ramsey ML, Getz CL. Effect of Humeral Component Version on Outcomes in Reverse Shoulder Arthroplasty. Orthopedics. 2017 May 01; 40(3):179-186.
  13. Anderson DE, Williams RJ, DeBerardino TM, Taylor DC, Ma CB, Kane MS, Crawford DC. Magnetic Resonance Imaging Characterization and Clinical Outcomes After NeoCart Surgical Therapy as a Primary Reparative Treatment for Knee Cartilage Injuries. Am J Sports Med. 2017 Mar; 45(4):875-883.
  14. Garwood ER, Souza RB, Zhang A, Zhang AL, Ma CB, Link TM, Motamedi D. Axial traction magnetic resonance imaging (MRI) of the glenohumeral joint in healthy volunteers: initial experience. Clin Imaging. 2017 Mar - Apr; 42:178-182.
  15. Facchetti L, Schwaiger BJ, Gersing AS, Guimaraes JB, Nardo L, Majumdar S, Ma BC, Link TM, Li X. Cyclops lesions detected by MRI are frequent findings after ACL surgical reconstruction but do not impact clinical outcome over 2 years. Eur Radiol. 2017 Aug; 27(8):3499-3508.
  16. Gong J, Pedoia V, Facchetti L, Link TM, Ma CB, Li X. Bone marrow edema-like lesions (BMELs) are associated with higher T1? and T2 values of cartilage in anterior cruciate ligament (ACL)-reconstructed knees: a longitudinal study. Quant Imaging Med Surg. 2016 Dec; 6(6):661-670.
  17. Zhang AL, Sing DC, Dang DY, Ma CB, Black D, Vail TP, Feeley BT. Overlapping Surgery in the Ambulatory Orthopaedic Setting. J Bone Joint Surg Am. 2016 Nov 16; 98(22):1859-1867.
  18. Guimaraes JB, Facchetti L, Schwaiger BJ, Gersing AS, Majumdar S, Ma BC, Li X, Link TM. Evolution of Intrameniscal Signal-Intensity Alterations Detected on MRI Over 24 Months in Patients With Traumatic Anterior Cruciate Ligament Tear. AJR Am J Roentgenol. 2017 Feb; 208(2):386-392.
  19. Pedoia V, Su F, Amano K, Li Q, McCulloch CE, Souza RB, Link TM, Ma BC, Li X. Analysis of the articular cartilage T1? and T2 relaxation times changes after ACL reconstruction in injured and contralateral knees and relationships with bone shape. J Orthop Res. 2017 03; 35(3):707-717.
  20. Li Q, Amano K, Link TM, Ma CB. Advanced Imaging in Osteoarthritis. Sports Health. 2016 Sep; 8(5):418-28.

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.