Jaimo Ahn
Harold W and Helen L Gehring Research Professor of Orthopaedic Surgery
Professor of Orthopaedic Surgery
Associate Chair, Orthopaedic Surbery
Section Head and Service Chief
Faculty Affairs
Orthopaedic Trauma Surgery

Available to mentor

Jaimo Ahn
Clinical Professor
  • About
  • Links
  • Center Memberships
  • Research Overview
  • Recent Publications
  • About

    Dr. Ahn is a surgeon who specializes in caring for those who have sustained orthopaedic trauma and those in need of fracture-related care.

    He was born in Seoul, Korea, and grew up in Chicago, Los Angeles, and the San Francisco Bay Area. His higher educational tour began at Stanford University (where he became enthralled with medicine, science, and education) followed by a research year at the University of California, San Francisco, and a move across the country to Philadelphia to the University of Pennsylvania, where he completed his MD, Ph.D. (in Cell and Molecular Biology), Post-Doctoral Fellowship (Molecular Orthopaedics) and Residency (Orthopaedic Surgery). He then rounded out his education with a Fellowship in orthopaedic traumatology at Hospital for Special Surgery / Cornell University, an AO Fellowship in orthopaedic trauma and hip surgery at Inselspital (University of Bern, Switzerland), and finally, an AOA Travelling Fellowship through Western Canada and the US. After almost 25 years at Penn, he joined Michigan Orthopaedics to help lead orthopaedic trauma as well as the education and professional development of trainees and fellow faculty.

    When not caring for patients, he has helped lead his field and musculoskeletal health in the US and internationally through foundations such as the US Bone and Joint Initiative, Foundation for Orthopaedic Trauma and AO Foundation, academic publications such as NEJM, JAMA, and Cochrane Collaborative and professional organization such as the Orthopaedic Trauma Association, Association of Bone and Joint Surgeons and American Physician Scientists Association, and governmental agencies such as the National Institutes of Health (NIH) and Congressionally Directed Medical Research Programs (DoD). He is especially proud of his international service through Orthopaedics Overseas (Nicaragua), BUP (Botswana), Mada Foundation / Sign International (Madagascar), and his teaching-mentoring service to thousands of students, residents, fellows, and young faculty all over the world.

    Clinical Interests

    Dr. Ahn’s mission is to provide the best skeletal trauma/fracture care possible—while being compassionate, experienced & evidence-based, patient & family oriented—to every one of his patients. He has applied these principles to care for those injured locally and regionally and those from South America, Asia, Europe, and Africa who have sought his care.

    Complex extremity & periarticular (around the joint) fractures
    Pelvic & acetabular (hip socket) fractures
    Nonunions (not healing), malunions (healed crooked), and osteomyelitis (bone infections)
    Limb salvage (preventing amputations) and distraction osteogenesis (bone regeneration/lengthening)


    • Pub Med
    • https://scholar.google.com/citations?user=nXqMCuwAAAAJ
    Center Memberships
    • Center Member
      Institute for Healthcare Policy and Innovation
    Research Overview

    Research Interests (for indexed publications, see here; for Google Scholar, see here https://bit.ly/jaimoahn-gscholar (link is external))

    1. Trauma/fracture outcomes, including clinical trials
    • Fracture fixation in the operative management of hip fractures (FAITH). Lancet, 389:1519-1527. 2017.
    • Fractures in Elderly Americans Associated With Walking Leashed Dogs. JAMA Surgery, 154:458-459. 2019
    • Total Hip Arthroplasty or Hemiarthroplasty for Hip Fracture. NEJM, 381:2199-2208. 2019.
    • Reconstruction of Traumatic Defects of the Tibia with Free Fibular Flap and External Fixation. Annals of Plastic Surgery, 85:516-521. 2020.
    • Simple Surgical Mask Modification for Increased Respiratory Protection during SARS-CoV-2. PLoS ONE, 17:e0272834. 2022.
    • Real-Time Identification of Life-Threatening Necrotizing Soft-Tissue Infections Using Indocyanine Green Fluorescence Imaging. In preparation,
    2. Surgical/medical decision-making
    • Crowd Intelligence for the Classification of Fractures and Beyond. PLoS One, 6:e27620. 2011.
    • Applying Evidence-Based Medicine to Hip Fracture Management. Frontiers in Surgery. 1:40. 2014.
    • Shared Decision Making, Fast and Slow. JAAOS, 24:495-502. 2016.
    • Defining the Key Parts of a Procedure. JAAOS, 26:142-147. 2018.
    • Predicting Life Expectancy Following Geriatric Hip Fracture. PLoS One, 16:e0261279. 2021.
    • Unipolar Hemiarthroplasty, Bipolar Hemiarthroplasty, or Total Hip Arthroplasty for Hip Fracture in Older Individuals. Journal of Bone and Joint
    Surgery, 106:120-128. 2024.
    3. Surgical/biomedical education
    • Factors affecting Interest in Orthopaedics Among Female Medical Students: A Prospective Analysis. Orthopaedics, 34:919-932. 2011.
    • Reinvigorating the Physician-Scientist Pipeline. JCI, 125:883-887. 2015.
    • Leading From the Front: An Approach to Increasing Racial and Ethnic Diversity in Surgical Training Programs. Annals of Surgery, 269:1012-1015.
    • Motivations and impact of international rotations in low- and middle-income countries for orthopaedic surgery residents: Are we on the same
    page? American Journal of Surgery, 221(2):245-253. 2020.
    • Impact of the SARS-CoV-2 Outbreak on ACGME-Accredited Orthopaedic Trauma Fellowship Training. Injury, ePub, Oct 16, 2023.
    • Effect of Cognitive Task Simulation in Transfer of Performance Skills in an AO Practical Skills Lab). In press, JOT, 2024
    4. Literature synthesis / evidence-based medicine
    • Venous Thromboembolism Prophylaxis in Orthopaedic Trauma Patients. JOT, 29:e355-362. 2015.
    • Acute Compartment Syndrome. JOT, 32:e181-e184. 2018.
    • Randomized-Controlled Trials for Geriatric Hip Fractures are Rare and Underpowered. JBJS, 101:e132. 2019.
    • Lower Extremity Fracture Management in Chronic Spinal Cord Injury: 2020 Delphi Consensus Recommendations. In press (JBJS Open Access),
    • WikiGuidelines for the Management of Pyogenic Osteomyelitis in Adults. Journal of the American Medical Association (JAMA) Network Open,
    5:e2211321. 2022
    • Principles for management of hip fracture for older adults taking direct oral anticoagulants: an international consensus statement. Anaesthesia
    epub Feb 6, 2024.
    5. Molecular regulation of bone healing and re/generation
    • R-spondin-2 is an osteoblast-produced Wnt agonist that regulates osteoblastogenesis. Bone Research (Nature Press), 6:24. 2018.
    • Bone marrow adipogenic lineage precursor (MALP) cells regulate osteoclastogenesis during bone remodeling and pathologic bone loss. JCI,
    November 18, 2020.
    • Targeting cartilage EGFR pathway for osteoarthritis treatment. Science TM, January 13, 2021.
    • The critical role of Hedgehog-responsive mesenchymal progenitors in meniscus development and injury repair. eLife, 10:e62917. 2021.
    • Activin A marks a novel progenitor cell population during fracture healing and reveals a therapeutic strategy. eLife, 10:e89822. 2023.
    • A Murine Delayed-Healing Model Associates Immune Response with Functional Bone Regeneration after Trauma. Preprint bioRxiv v1 deposit on
    Oct 31, 2023.
    6. Michigan Orthopaedic Trauma Research (MOTR)
    • Preoperative Comorbidities Associated With Early Mortality in Hip Fracture Patients: A Multicenter Study. Journal of the American Academy of
    Orthopaedic Surgeons, 31:81-86. 2023.
    • Comparison of true blood loss between short and long cephalomedullary nail fixation of geriatric hip fractures, a retrospective cohort study.
    Journal of Orthopaedic Trauma, ePub March 11, 2023.
    • Operative Technique for Sacral Insufficiency Fractures Causing Spinopelvic Dissociation: A Case Report. Journal of Bone and Joint Surgery Case
    Connector, 3(1). 2023.
    • Full Reversal of Anticoagulants Prior to Cephalomedullary Fixation of Geriatric Hip Fractures May Not Be Necessary. Journal of Orthopaedic
    Trauma, 37:444-449. 2023.
    • Disuse Osteopenia Development With Non Weight-Bearing: CT Hounsfield-Unit-Based Analysis. Journal of Orthopaedic Research, epub Oct 7,
    • DXA Screening for Transgender and Gender Diverse Patients: An Overview of Current Guidance and Call for Improved Protocols. Academic
    Radiology, epub Nov 15, 2023.

    Recent Publications See All Publications
    • Journal Article
      Principles for management of hip fracture for older adults taking direct oral anticoagulants: an international consensus statement.
      Mitchell RJ, Wijekulasuriya S, Mayor A, Borges FK, Tonelli AC, Ahn J, Seymour H, Fragility Fracture Network Hip Fracture Audit Special Interest Group . Anaesthesia, 2024 Jun; 79 (6): 627 - 637. DOI:10.1111/anae.16226
      PMID: 38319797
    • Journal Article
      DEXA Screening for Transgender and Gender Diverse Patients: An Overview of Current Guidance and Call for Improved Protocols.
      Jacobson AR, Blaszczak J, Ahn J, Viglianti BL. Acad Radiol, 2024 May; 31 (5): 2159 - 2163. DOI:10.1016/j.acra.2023.10.037
      PMID: 37977892
    • Journal Article
      The rate of disuse osteopenia in admitted, non-weight-bearing patients.
      Walley KC, Farrar NR, Muralidharan A, Monovoukas DA, Eichman J, Klueh MP, Baumann AN, Perdue AM, Hake ME, Ahn J. J Orthop Res, 2024 Apr; 42 (4): 806 - 810. DOI:10.1002/jor.25713
      PMID: 37804218
    • Journal Article
      CD47 is Required for Mesenchymal Progenitor Proliferation and Fracture Repair.
      Hankenson K, Zondervan R, Capobianco C, Jenkins D, Reicha J, Frederick L, Lam C, Isenberg J, Ahn J, Marcucio RS. Res Sq, 2024 Mar 19; DOI:10.21203/rs.3.rs-4022423/v1
      PMID: 38562718
    • Preprint
      CD47 is Required for Mesenchymal Progenitor Proliferation and Fracture Repair.
      Zondervan RL, Capobianco CA, Jenkins DC, Reicha JD, Fredrick LM, Lam C, Isenberg JS, Ahn J, Marcucio RS, Hankenson KD. 2024 Mar 6; DOI:10.1101/2024.03.06.583756
      PMID: 38496546
    • Journal Article
      Biomechanics of fracture healing: how best to optimize your construct in the OR.
      Hast M, Glatt V, Archdeacon M, Ledet E, Lewis G, Ahn J, Haller J. OTA Int, 2024 Mar; 7 (2 Suppl): e304 DOI:10.1097/OI9.0000000000000304
      PMID: 38487404
    • Journal Article
      Unipolar Hemiarthroplasty, Bipolar Hemiarthroplasty, or Total Hip Arthroplasty for Hip Fracture in Older Individuals.
      Okike K, Prentice HA, Chan PH, Fasig BH, Paxton EW, Bernstein J, Ahn J, Chen F. J Bone Joint Surg Am, 2024 Jan 17; 106 (2): 120 - 128. DOI:10.2106/JBJS.23.00486
      PMID: 37973035
    • Journal Article
      How do surgeons decide when to treat proximal humerus fractures with operative versus nonoperative management?
      Reed LA, Hao KA, Patch DA, King JJ, Fedorka C, Ahn J, Strelzow JA, Hebert-Davies J, Little MTM, Krause PC, Johnson JP, Spitler CA. Eur J Orthop Surg Traumatol, 2023 Dec; 33 (8): 3683 - 3691. DOI:10.1007/s00590-023-03610-1
      PMID: 37300588