Jaimo Ahn, MD, PhD, FACS

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Adjunct Associate Professor of Orthopaedic Surgery
Attending Orthopaedic Surgeon , Hospital of the University of Pennsylvania, Penn-Presbyterian Medical Center,Pennsylvania Hospital, Philadelphia, PA
Assistant Director, Orthopaedic Surgery Residency Program, University of Pennsylvania
Co-Director, Penn Orthopaedic Trauma and Fracture Reconstruction
Associate Director, Orthopaedic Surgery Residency Program , University Pennsylvania
Advisory Dean, University of Pennsylvania
Department: Orthopaedic Surgery

Contact information
University of Michigan
1500 E Medical Center Drive
2914F Taubman Center
Ann Arbor, MI 48109
Office: 734) 936-5718
Fax: (734) 936-3277
BS (Biological Sciences)
Stanford University, 1994.
PhD (Cell & Molecular Biology)
University of Pennsylvania School of Medicine, 1999.
MD (Medicine)
University of Pennsylvania School of Medicine, 2003.
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Description of Research Expertise

I am an MD-PhD clinician-scientist with medical and scientific interest in the outcomes of orthopaedic trauma and fracture treatment and the molecular enhancement of bone formation and fracture healing. My investigative goals include the identification of interventions (biological, mechanical/surgical, decision-making) that improve patient care, to better understand them in the laboratory and to adapt them to the patient population that I treat. To those ends, I work with several interdisciplinary teams consisting of biologists, engineers, surgeons, veterinarians, clinical investigators to enhance our understanding and provision of orthopaedic care.

>> Gene regulation in bone healing - Using my background in molecular biology and gene regulation, I have delved into the investigation of a number of pathways and processes in bone healing and regulation that are consistent and synergistic with my orthopaedic trauma practice. I utilize primarily mouse models of traumatic fracture healing (with my collaborator, Kurt Hankenson) and have studied pathways related to thrombospondins, Wnt and Notch; and I have been especially interested in the geriatric condition (both fractures and bone loss). Select publications:
• Hebb JH, Ashley JW, McDaniel L, Lopas LA, Tobias J, Hankenson KD, Ahn J. Bone healing in an aged murine fracture model is characterized by sustained callus inflammation and decreased cell proliferation. J Orthop Res. Epub Jul 14, 2017.
• Ashley JW, Ahn J, Hankenson KD. Notch signaling promotes osteoclast maturation and resorptive activity. J Cell Biochem. 2015 Nov;116(11):2598-609.
• Lopas LA, Belkin NS, Mutyaba PL, Gray CF, Hankenson KD, Ahn J. Fractures in geriatric mice show decreased callus expansion and bone volume. Clin Orthop Relat Res. 2014 Nov;472(11):3523-32.
• Mutyaba PL, Belkin NS, Lopas L, Gray CF, Dopkin D, Hankenson KD, Ahn J. Notch signaling in mesenchymal stem cells harvested from geriatric mice. J Orthop Trauma. 2014;28 Suppl 1:S20-3.
• Dishowitz MI, Mutyaba PL, Takacs JD, Barr AM, Engiles JB, Ahn J, Hankenson KD. Systemic inhibition of canonical Notch signaling results in sustained callus inflammation and alters multiple phases of fracture healing. PLoS One. 2013 Jul 3;8(7):e68726.

>> Improving paradigms of medical decision-making - My investigations have led me to become involved in the systematic analysis of orthopaedic outcomes data and the systematic dissemination of education and information regarding evidence-based medicine. My collaborator, Joseph Bernstein, and I have taken this a step further and asked how to take medical decision-making into the future by not only refining what we know but exploring new methods to create improved paradigms to come to better clinical conclusions. Select publications:
• Bernstein J, LeBrun D, MacCourt D, Ahn J. Presumed consent: licenses and limits inferred from the case of geriatric hip fractures. BMC Med Ethics. 2017;18(1):17.
• Bernstein J, Kupperman E, Kandel LA, Ahn J. Shared Decision Making, Fast and Slow: Implications for Informed Consent, Resource Utilization, and Patient Satisfaction in Orthopaedic Surgery. J Am Acad Orthop Surg. 2016;24:495-502.
• Bernstein JR, Maliha G, Ahn J, Bernstein J. Levels of Influence: Habituation and the Prevalence of Declared Conflicts of Interest. J Bone Joint Surg Am. 2016 Nov 16;98(22):e99.
• Bernstein J, Morshed S, Helfet DL, Bhandari M, Ahn J. Applying evidence-based medicine principles to hip fracture management. Front Surg. 2014 Oct 20;1:40.
• Bernstein J, Long JS, Veillette C, Ahn J. Crowd intelligence for the classification of fractures and beyond. PLoS One. 2011;6(11):e27620.

>> Medical education (especially, the clinician-scientist) - Advances in biomedicine are driven by clinically minded scientists and scientifically minded clinicians. I have been studying, refining, improving, advocating for greater data-driven education and resource allocation for the training of medical scientists and clinician-scientists from the stages of undergraduate medical education and throughout graduate training. Select publications:
• Winterton M, Ahn J, Bernstein J. The prevalence and cost of medical student visiting rotations. BMC Med Educ. 2016 Nov 14;16(1):291.
• Schenker ML, Baldwin KD, Israelite CL, Levin LS, Mehta S, Ahn J. Selecting the Best and Brightest: A Structured Approach to Orthopedic Resident Selection. J Surg Educ. 2016 May 23.
• Daye D, Patel CB, Ahn J, Nguyen FT. Challenges and opportunities for reinvigorating the physician-scientist pipeline. J Clin Invest. 2015 Mar 2;125(3):883-7.
• Atesok KI, Hurwitz SR, Egol KA, Ahn J, Owens BD, Crosby LA, Pellegrini VD Jr. Perspective: Integrating research into surgical residency education: lessons learned from orthopaedic surgery. Acad Med. 2012 May;87(5):592-7.
• Baldwin K, Namdari S, Bowers A, Keenan MA, Levin LS, Ahn J. Factors affecting interest in orthopedics among female medical students: a prospective analysis. Orthopedics. 2011 Dec 6;34(12):e919-32.

>> The Practice of orthopaedic surgery. Select publications:
• Baron MD, DeFrancesco CJ, Liu TC, Leone FT, Ahn J. A Teachable Moment After Orthopaedic Fracture in the Smoking Patient: A Randomized, Controlled Trial. J Orthop Trauma. 2017;31(8):e252-e254.
• Bernstein J, Roberts FO, Wiesel BB, Ahn J. Preoperative Testing for Hip Fracture Patients Delays Surgery, Prolongs Hospital Stays, and Rarely Dictates Care. J Orthop Trauma. 2016 Feb;30(2):78-80.
• Sagi HC / Ahn J, Ciesla D, Collinge C, Molina C, Obremskey WT, Guillamondegui O, Tornetta P 3rd; Orthopaedic Trauma Association Evidence Based Quality Value and Safety Committee. Venous Thromboembolism Prophylaxis in Orthopaedic Trauma Patients: A Survey of OTA Member Practice Patterns and OTA Expert Panel Recommendations. J Orthop Trauma. 2015 Oct;29(10):e355-62.
• Scolaro JA, Schenker ML, Yannascoli S, Baldwin K, Mehta S, Ahn J. Cigarette smoking increases complications following fracture: a systematic review. J Bone Joint Surg Am. 2014 Apr 16;96(8):674-81.
• Schenker ML, Yannascoli S, Baldwin KD, Ahn J, Mehta S. Does timing to operative debridement affect infectious complications in open long-bone fractures? A systematic review. J Bone Joint Surg Am. 2012 Jun 20;94(12):1057-64.

I welcome discussion especially from students and trainees.

Jaimo Ahn, MD, PhD, FACS
Advisory Dean | Admissions & MSTP Steering Committees
Medical Student & Assoc. Residency Director, Orthopaedic Surgery
Co-Director, Orthopaedic Trauma & Fracture Reconstruction
Perelman School of Medicine, University of Pennsylvania

Selected Publications

Huang D, Weaver F, Obremskey WT, Ahn J, Peterson K, Anderson J, Veazie S, Carbone LD.: Treatment of Lower Extremity Fractures in Chronic Spinal Cord Injury: A Systematic Review of the Literature. PM R 13: 510-527, May 2021.

Roberts HJ, Albright PD, Shearer DW, Won N, MacKechnie MC, Richard Coughlin R, Miclau T 3rd, Morshed S, Sabharwal S; COACT Resident Rotation Study Group.: Motivations and impact of international rotations in low- and middle-income countries for orthopaedic surgery residents: Are we on the same page? Am J Surg 221: 245-253, Feb 2021.

Yu W, Zhong L, Yao L, Wei Y, Gui T, Li Z, Kim H, Holdreith N, Jiang X, Tong W, Dyment N, Liu XS, Yang S, Choi Y, Ahn J, Qin L.: Bone marrow adipogenic lineage precursors promote osteoclastogenesis in bone remodeling and pathologic bone loss. J Clin Invest 131: e140214, Jan 2021.

Wei Y, Luo L, Gui T, Yu F, Yan L, Yao L, Zhong L, Yu W, Han B, Patel JM, Liu JF, Beier F, Levin LS, Nelson C, Shao Z, Han L, Mauck RL, Tsourkas A, Ahn J, Cheng Z, Qin L.: Targeting cartilage EGFR pathway for osteoarthritis treatment. Sci Transl Med 13: eabb3946, Jan 2021.

DeAngelis RD, Minutillo GT, Stein MK, Schemitsch EH, Bzovsky S, Sprague S, Bhandari M, Donegan DJ, Mehta S; HEALTH Investigators.: Who Did the Arthroplasty? Hip Fracture Surgery Reoperation Rates are Not Affected by Type of Training-An Analysis of the HEALTH Database. J Orthop Trauma 34: S64-S69, Nov 2020.

Neilly D, MacDonald DRW, Sprague S, Bzovsky S, Axelrod D, Poolman RW, Frihagen F, Heels-Ansdell D, Bhandari M, Schemitsch EH, Stevenson IM; HEALTH Investigators.: Predictors of Medical Serious Adverse Events in Hip Fracture Patients Treated With Arthroplasty. J Orthop Trauma 34: S42-S48, Nov 2020.

Blankstein M, Schemitsch EH, Bzovsky S, Poolman RW, Frihagen F, Axelrod D, Heels-Ansdell D, Bhandari M, Sprague S, Schottel PC; HEALTH Investigators.: What Factors Increase Revision Surgery Risk When Treating Displaced Femoral Neck Fractures With Arthroplasty: A Secondary Analysis of the HEALTH Trial. J Orthop Trauma 34: S49-S54, Nov 2020.

Noori A, Sprague S, Bzovsky S, Schemitsch EH, Poolman RW, Frihagen F, Axelrod D, Heels-Ansdell D, Bhandari M, Busse JW; HEALTH Investigators.: Predictors of Long-Term Pain After Hip Arthroplasty in Patients With Femoral Neck Fractures: A Cohort Study. J Orthop Trauma 34: S55-S63, Nov 2020.

MacDonald DRW, Neilly D, Schneider PS, Bzovsky S, Sprague S, Axelrod D, Poolman RW, Frihagen F, Bhandari M, Swiontkowski M, Schemitsch EH, Stevenson IM; FAITH and HEALTH Investigators.: Venous Thromboembolism in Hip Fracture Patients: A Subanalysis of the FAITH and HEALTH Trials. J Orthop Trauma 34: S70-S75, Nov 2020.

Würdemann FS, Poolman RW, Krijnen P, Bzovsky S, Sprague S, Kaptein BL, Hegeman JH, Schemitsch EH, Bhandari M, Swiontkowski M, Schipper IB; Dutch Hip Fracture Audit Group and FAITH Investigators.: Clockwise Torque of Sliding Hip Screws: Is There a Right Side? J Orthop Trauma 34: S76-S80, Nov 2020.

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Last updated: 05/09/2021
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