Jacksonville, Florida




The research of Mary I. O'Connor, M.D., focuses on joint replacement surgery of the hip and knee, as well as limb salvage surgery for bone and soft tissue tumors.

Dr. O'Connor is a co-investigator in a new pilot study to determine if injecting a patient's stem cells into his or her arthritic knee joint will slow the progression of, or even reverse, the osteoarthritis.

She is also particularly interested in the influence of gender on treatment and outcomes in arthritis — women have a higher disease burden and oftentimes less optimal outcomes — and research into improving the process of care delivery as a means of improving quality and decreasing costs.

Dr. O'Connor is leading a study into potential differences in knee tissues between men and women with knee arthritis in an effort to better understand why women develop more knee arthritis than men. Also being investigated is whether women ask more and different questions related to knee surgery.

In addition, Dr. O'Connor has been engaged in research with computer-assisted navigation for knee replacement surgery and has also continued research on bone and soft tissue tumors.

Focus areas

  • Knee osteoarthritis. Dr. O'Connor and her colleagues Shane A. Shapiro, M.D., Abba C. Zubair, M.D., Ph.D., and Joseph M. Bestic, M.D., are investigating if stem cells can slow the progression of arthritis or even reverse it. Stem cells will be aspirated from a patient's pelvic bone, concentrated and injected into the knee joint of subjects with mild to moderate arthritis. Magnetic resonance imaging will be performed at baseline and follow-up. The synovial (joint) fluid will be studied to see if there is any change in the inflammatory markers.

    Dr. O'Connor is the lead investigator of a multicenter study researching if there are sex differences in the tissues of the knee joint between men and women with knee osteoarthritis. The purpose of this research is to gain insight into why women develop more knee osteoarthritis than men.

  • Knee replacement surgery. Dr. O'Connor and her partner, Mark P. Brodersen, M.D., have completed a study on computer-assisted navigation in total knee arthroplasty and are preparing the manuscript for publication. Their findings showed that the use of navigation improved the likelihood of better limb alignment in patients undergoing surgery.

    With the assistance of their anesthesiology colleagues, Drs. O'Connor and Brodersen also studied whether the use of computer-assisted navigation in knee replacement surgery decreased the risk of patients having fat emboli (normal fat and bone marrow going from the knee bones to the lung during the course of the knee replacement surgery). They did not see a benefit with navigation.

  • Limb salvage surgery. Dr. O'Connor considers her practice as an orthopedic oncologist (tumor surgeon) to be one of the most rewarding and most challenging aspects of her practice. Continued research is needed into how to better perform limb salvage surgery on patients, with a focus on making these reconstructions last for decades and function well.

    Dr. O'Connor and her mentor, Franklin H. Sim, M.D., wrote a landmark medical paper in 1989 on the Mayo Clinic experience with limb salvage for cancerous pelvis tumors. Dr. O'Connor is now serving as a mentor to a talented young orthopedic oncologist, Courtney E. Sherman, M.D., and they published a 20-year follow-up study on these patients. Such long-term studies are difficult to do and not commonly performed, yet they are of critical importance to understanding how these treatments have worked.

  • Health care process improvement. Dr. O'Connor and her colleagues strive to provide the best value for their patients: the highest quality of care at the lowest cost. Dr. O'Connor has chaired a recent Lean project to reduce waste in the total joint program.

    Dr. O'Connor and Michael R. Vizzini published about their experience with the addition of nonoperative musculoskeletal physicians to the orthopedic department. They showed that these physicians provide excellent musculoskeletal care to patients and, when appropriate, promptly involve a surgical partner. Patient and referring physician satisfaction were very high.

    With her fellows and partners, Dr. O'Connor is engaged in a research study to look at the use of a medicine to decrease the need for blood transfusions after total hip and knee replacement surgery. If positive, this study may lead to improved safety for patients and lower health care costs.

Significance to patient care

Dr. O'Connor's research focuses on how to improve the treatment of knee osteoarthritis. By studying potential sex differences in knee osteoarthritis, it may be possible to decrease the high burden of knee arthritis in women.

With their exciting new research on the use of stem cells in the treatment of osteoarthritis of the knee, Dr. O'Connor and her colleagues may ultimately find an effective means to treat arthritis without joint replacement surgery.

Professional highlights

  • Co-Chair and Co-Editor, American Academy of Orthopaedic Surgeons/Orthopaedic Research Society/Association of Bone and Joint Surgeons (AAOS/ORS/ABJS) Musculoskeletal Healthcare Disparities Research Symposium, 2010 (published in Clinical Orthopaedics and Related Research, 2011)
  • Co-Editor, papers from the Combined Meeting of the International Symposium on Limb Salvage and the Musculoskeletal Tumor Society, 2009 (published in Clinical Orthopaedics and Related Research, 2010)
  • Member, Advisory Committee on Research on Women's Health, National Institutes of Health, 2006-2010
  • Co-Editor, Sexual Dimorphism in Musculoskeletal Health, Orthopaedic Clinics of North America, 2006
  • Co-Chair and Co-Editor, Carl T. Brighton Workshop on Metastatic Bone Disease, 2002 (published in Clinical Orthopaedics and Related Research, 2003)


Academic Rank

  1. Professor of Orthopedics


  1. Fellow - Orthopedic Oncology Department of Orthopedics, Mayo Graduate School of Medicine, Mayo Clinic College of Medicine
  2. Resident Silicon Graphics, Inc.
  3. Resident Department of Orthopedics, Mayo Graduate School of Medicine, Mayo Clinic College of Medicine
  4. Resident Orthopedic Surgery, Programs in Rochester, Mayo School of Graduate Medical Education, Mayo Clinic College of Medicine
  5. Internship Department of Orthopedics, Mayo Graduate School of Medicine, Mayo Clinic College of Medicine
  6. MD Medical College of Pennsylvania
  7. BA - Biochemistry Yale University

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