Orthopedic Surgeon

Picture of Dr Michael Y Chang Doctor of Osteopathic Medicine



  • Walnut Creek


“My goal is to restore maximum function with the highest level of quality care so that my patients can get back to living life.”


Can I See Dr Contreras?

    2405 Shadelands Drive
    Walnut Creek CA 94598

  • Monday – Thursday
    8:00 AM – 5:00 PM

    8:00 AM – 4:00PM


With Dr Contreras


About Dr Contreras

Dr. Contreras began practicing orthopedic medicine in 1991 after receiving his medical degree and completing his internship and residency at University of California, San Francisco. His ensuing fellowship in orthopedic trauma prepared him for a challenging position as Assistant Clinical Professor for the Department of Orthopedic Surgery at UCSF’s School of Medicine, and lead to his appointment as the acting Chief of the Orthopaedic Department at San Francisco General Hospital.

Dr. Contreras is Board Certified in Orthopaedic Surgery and has more than 25 years of experience in treating patients.

Dr. Contreras applies his years of experience and knowledge daily to overcome orthopedic challenges. His thoroughness and contemplative nature ensure all avenues are explored when planning treatment, and his traditional values and personable demeanor offer patients comfort in addition to superior medicine.

An educator by nature, he has lectured and authored several articles on his specialty.

  • Board Certification

    • Orthopaedic Trauma

      San Francisco General Hospital, San Francisco, CA 1990

  • Fellowship

    • Orthopaedic Trauma

      San Francisco General Hospital, San Francisco, CA 1988

  • Residency

    • Orthopaedic Surgery

      University of California, San Francisco, 1987

  • Internship

    • Intern

      University of California, San Francisco, 1983

  • Medical School

    • MD

      University of California, San Francisco, 1982

  • College

    • BA

      University of California, Los Angeles, 1978


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About Dr Contreras

Ppennie Wachter
Dec 28, 2022

Dr. Contreas is very easy to talk to. My experience was very positive & I would recommend him to my friends & family.

E V Bond
Dec 15, 2022

I have been Dr. Contreras patient for 6 years. His professionalism is unequal. He explained to me in laymen terms with drawing my problems. Will recommend him to anybody that’ll need a knee doctor.

Michael Quillin
May 08, 2022

Understood the issue with my knee and actually took the time to drain the swelling and put in some cortisone. I did not expect such prompt relief. It was wonderful!

Frank Casillas
Apr 08, 2022

Dr. David Contreras is highly skilled, caring, friendly and engaging. I highly recommend him, his staff and facilities.

John Techwriter
Mar 05, 2022

I'm a senior with a history of back problems, but it was severe pain in my hips that got me referred to Dr. Contreras. The preliminary diagnosis was osteoarthritis of the hip joint, but Dr. Contreras was not satisfied that this was the true cause of my hip pain. Before our initial visit, he took the trouble to review the lumbar fusion surgery I had three years ago. During our visit he showed me x-rays of my hips taken back in 2019, indicating nascent osteoarthritis. Then he had a new hip x-ray taken on the spot and was able to suggest that though my arthritis had spread, it did not seem serious enough to cause the hip and thigh pain I was experiencing. And then it hit me. Back in 2019 I had severe sciatica due to a spinal nerve root being trapped between a bone spur and a misaligned vertebra. Back then I was sure I had a hip problem because the sciatic nerve referred my pain to the joint of my right hip. Dr. Contreras suggested the same thing could be happening again. Before treating me for arthritis -- I was hoping for a hip replacement ASAP because the pain was so bad -- Dr. Contreras ordered an MRI of my spine and also a CT scan. They will be coming up in the next week. Together we will go over the results, and from the information presented on those slides will be able to determine the exact cause of my hip pain. Then and only then will we set about a course of treatment. I am immensely grateful to Dr. Contreras for not rubber-stamping the initial diagnosis, and instead taking the time required to familiarize himself with my history and specify additional testing to be absolutely sure. The story is not over, but already I am pretty sure that had I seen a less experienced and thorough specialist, I could have been directed down the wrong path and wasted precious years finding my way back.

Jan 05, 2022

Dr Contreras is the BEST! He’s very polite. His expertise gives me the assurance that he’s doing the best for me. I’ve been seeing him for many years for my knees. I’m so GRATEFUL for the care he gives me. I can function and live independently on my own. You can’t go wrong with Dr Conteras he’s very down to earth and he listens to what you have to say! He truly CARES for his patients.

Lasocurrencias Demonse
Aug 05, 2021

(Translated by Google) Excellent, they treated me very well, they explained to me in an excellent way, they helped me understand several things about myself, Dr. David Contreras is a person with a very big heart. Friendly and respectful I recommend it 100% (Original) Excelente, me atendieron muy bien, me explicaron de manera exelente me ayudaron a entender varias cosas propias el Dr David Contreras es una persona de muy grande corazón. Amable y respetuoso lo recomiendo al 100%

Val L.
Mar 31, 2020

Dr. Contreras has treated me for about 2 years for both knees which need replacement. He is caring and also explains everything in detail. For now I am having injections for the pain but when I am ready to have them replaced I know he will be there for me. I have all the confidence in the world for him and would recommend him highly.

Sandra S.
Jun 14, 2019

Dr. Contreras I can never put into the right words to how you have made my life complete I was given a chance when no one such as yourself could even do such a thing for a stranger such as myself you were my trauma doctor at John Muir  medical center my legs were supposed to be Abby Tate it the night that I was brought into you March 22, 1993 Dr. to Shango was going to Ampitate  take them both of my legs ! you came in and said no I'm going to  give my all into saving this lady's legs ( Sandra Shorter/ DeGeest she is young 23 years old and is a mother!! was in a coma so I didn't even know that someone who just fixed a strangers legs in Trauma!!just blessed me grateful and forever impacted by your personal care for a patient on top of your job title of saving people's lives people you don't even know you give them your all into making them have a functional normal as can be life ahead of themYou are a very positive no negativity Doctor Who says that he will take time and I will be able to see me walk again someday I did exactly that from your words of wisdom and your positive justification. You are a one in the million people in this life on earth with all the people That you put back together the best of your knowledge you possibly can and hopes that they can live a normal life like others. I think you and every way from my whole heart mind and soul thank you David Contreras you are simply the number one best orthopedic doctors there could Ever be . You gave me hope you gave me a life again ... Thank you Dr.David Contreras

Tara n.
Jul 26, 2018

Thank you doctor for being so professional and compassionate. This doctor is wonderful.

Assisting the Doctor:

Golden State Ortho Doctor showing caring hands

Golden State Ortho Doctors are assisted by our clinical support teams which include Medical Assistants, X-Ray Technicians and more.

Reviews Mean So Much!

Reviews mean so much to both the doctor providing care as well as to prospective patients. We appreciate your reviews!

- Val L

Dr Contreras has repaired and replaced both knees for my husband and just recently replaced my left knee. His experience and consideration is consistent and totally reassuring.

- Sandra L

Thank you doctor for being so professional and compassionate. This doctor is wonderful.

- Tara N