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Gregory S. DiFelice, MD

Trauma and Sports Medicine Surgeon
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About Dr. DiFelice


Dr. Gregory S. DiFelice is a fellowship-trained orthopedic surgeon specializing in Sports Traumatology and Joint Reconstruction Surgery at Hospital for Special Surgery and New York-Presbyterian Hospital. He also holds an academic appointment at the Weill Medical College of Cornell University as an Associate Attending Orthopedic Surgeon. His main surgical focus is on the treatment of the knee, shoulder, and hip. Using both non-surgical and surgical methods, he strives to utilize the latest technologies to improve patient outcomes, while preserving their native tissues. He refers to his customized approach as Preservation First, and this guides his practice. His philosophy, developed over 20+ years in practice, is to use surgery as a last resort, and if surgery is absolutely necessary, to perform the most conservative surgery that will give the best, most long-lasting results for the patient. This delicate balancing of the risks and benefits of surgery for each individual is, in essence, the art of surgery.

Dr. DiFelice is a surgical innovator and has developed several cutting-edge surgical techniques that allow him to save a patients’ torn ligaments, rather than replacing them, which is the current standard of care. His approach is called ligament preservation and includes conservative, minimally invasive techniques such as primary repair and primary repair with augmentation. By saving the patients’ native ligament tissues, he greatly reduces surgical injury to the patient, and thus diminishes the recovery time and restores more of the natural function of the knee. Currently, for 50% to 75% of his ACL injured patients, he is able to save most, if not all, of the patients’ native tissue, thereby diminishing the need for grafts. He uses ACL reconstruction – the replacing of the torn ligament with a graft, which is considered the standard of care throughout the world – only as a last resort when there is little or no native tissue available to save. As the surgical innovator of his modern-day preservation approach, he has published and lectured extensively, both domestically and internationally, on this and other topics.

Not all ligaments, nor all joints for that matter, can be saved, however. Dr. DiFelices’ Preservation First approach to surgery is also evident in his approach to arthritic joints. Rather than the standard approach of the majority of surgeons, in which most people with arthritis of the knee or hip get a total joint replacement surgery, his approach is more nuanced and is customized for each patient, based on their health, activity level and particular pattern of arthritis. He is an expert in both realignment osteotomy and robotic, unicompartmental arthroplasty – two techniques that allow the patient to avoid the larger, more morbid total joint arthroplasty when in their best interests. In addition, he is also an expert in both total hip and total knee arthroplasty, having performed thousands of these procedures over his 20+-year career, which allows him to provide patients with the treatment option that is best for them.

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Special Expertise

ACL and Ligament Preservation
Multi-ligament Knee Injury
Sports Trauma
Arthroscopic Knee surgery
Tendon repairs
Arthroplasty of the Knee and Hip

Watch Dr. DiFelice present his novel approach to ACL preservation


Knee arthroscopy
Shoulder arthroscopy
Knee ligament reconstruction & repair
Meniscal & cartilage surgery
Rotator cuff repair
Joint replacement of the knee and hip
Fracture surgery
Tendon repairs

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If your insurance is not listed, please call our office if you have questions regarding your insurance coverage. If you have out-of-network benefits, then your insurance may reimburse you for a portion of your office visit. We will work with you and your insurance to minimize your out-of-pocket costs. Financial assistance may be available for patients in need.



Associate Attending Orthopedic Surgeon, Hospital for Special Surgery
Associate Professor, Clinical Orthopedic Surgery, Weill Cornell Medical College
Associate Attending Orthopedic Surgeon, NewYork-Presbyterian Hospital


American Academy of Orthopaedic Surgeons
American Orthopaedic Society for Sports Medicine
American Association of Hip and Knee Surgeons
New York State Society of Orthopaedic Surgeons
Medical Society of the State of New York
Alpha Omega Alpha Medical Honor Society- NJ Beta Chapter


Board Certified, ABOS, July 2003


The Associate of Bone and Joint Surgeons Clinical Orthopedics and Related Research Multimedia Award 2011
Patient Choice Award - Vitals.com 2008, 2009, 2010,2011, 2013, 2014, 2016, 2017, 2018 
Teacher of the Year Award - Montefiore Orthopaedic Residency Program 2002 & 2005 


MD, UMDNJ- New Jersey Medical School, Newark, NJ/USA, 1994


General surgery, Santa Barbara Cottage Hospital, Santa Barbara, CA/USA, 1995


Orthopedic Surgery, Hospital for Special Surgery, New York, NY/USA, 1999


Sports Medicine, Washington University-Barnes Jewish Hospital, St. Louis, MO/USA, 2000

State Licensure



For My Patients

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ACL injuries have become commonplace, along with its traditional treatment of reconstruction. According to Dr. Gregory DiFelice, orthopedic sports trauma surgeon at HSS, one size does not fit all for ACL tears. He has developed an innovative approach to repair the native ACL in tears where the ligament is largely intact, but has been torn from its bony attachment. His technique saves the patient's native anatomy which results in better outcomes. Watch exclusive footage of his patients who have undergone this technique, all of which are included in the new results that Dr. DiFelice just published. To view the study, please visit: http://www.sciencedirect.com/science/article/pii/S0749806315006647.

Watch Dr. DiFelice present his novel approach to ACL preservation

Publications by Dr. DiFelice

Patient Education

Selected Journal Articles

Selected Books/Chapters


van der List JP, DiFelice GS. The Role of Ligament Repair in ACL Surgery. In: Ligamentous Injuries of the Knee, 2016, pp. 199-220.

DiFelice GS, van der List JP. Arthroscopic suture anchor primary ACL repair. In: Insall and Scott Surgery of the Knee (6th edition).

van der List JP, DiFelice GS. Primary Repair in the Pediatric Patient. In: The Pediatric ACL, 2017, Springer Publications. pp. 227-239.

Jonkergouw, Anne & Van der List, Jelle & Difelice, Gregory. (2019). Arthroscopic Primary Repair in the Multiple-Ligament Injured Knee. 10.1007/978-3-030-05396-3_14.

Vermeijden HD, Van der List JP, DiFelice GS. Cruciate ligament repair. The Complex Knee Management Guide: Restoring the Anatomy to Achieve Best Outcomes, in press.

Selected Presentations

Arthroscopic Primary Repair of Proximal Anterior Cruciate Ligament Tears: With or Without Additional Suture Augmentation? AOSSM Annual Meeting. San Diego, CA. July 5-7, 2018.

Arthroscopic primary repair of proximal anterior cruciate ligament tears:With or without internal brace? Poster presentation at the 18th Biennial Meeting of the European Society for Sports Traumatology, Knee Surgery and Arthroscopy, Glasgow, Scotland. May 9 – 12, 2018.

Good outcomes of arthroscopic primary repair of proximal anterior cruciate ligament tears are maintained at mid-term follow-up. Poster presentation at the 18th Biennial Meeting of the European Society for Sports Traumatology, Knee Surgery and Arthroscopy, Glasgow, Scotland. May 9 – 12, 2018.

The location of anterior cruciate ligament tears: a prevalence study using magnetic resonance imaging. Podium presentation at the 85th Annual Meeting of American Academy of Orthopaedic Surgeons, New Orleans, LA, USA. March 6 – 10, 2018.

DiFelice, GS. We can get ACL to heal-Techniques & results. Warwick Orthopaedics Sports Knee Conference. Staffordshire, UK. November 20-21, 2017.

Primary ACL Repair: Why We Don’t, Why We Should, and How I do It? 4th Joint Preservation Congress. Warsaw, Poland. September 14-16, 2017.

Case Presentation: Multi-Ligament Knee Reconstruction,Technique and Fixation DeviceChoices, Surgical & Patient Selection Tips for Successful Surgical Outcomes. Grand Rounds: Michigan State University. Grand Rapids, MI. May 16-17, 2017.

Emerging Technique: ACL Repair. 2017 Kaiser Permanente Dale Daniel Orthopaedic Symposium. Huntington Beach, CA. February 11, 2017.

The Incidence of Proximal Avulsion Anterior Cruciate Ligament Tears: A Magnetic Resonance Imaging Evaluation. E-poster presentation at 11th Biennial ISAKOS Congress. June 4 – 8, 2017, Shanghai, China.

Is There a Role for Primary Repair of ACL Injuries? National Capital Knee Symposium, University of Ottawa. Ottawa, Canada. September 15-16, 2016.

ACL Repair- is there a role? Fortius International Sports Injury Conference. London, UK. October 12-13, 2015.

Surgical Spotlight: Overview of Anterolateral Ligament. AOSSM Annual Meeting 2015. Orlando, FL. July 9-12, 2015.

Suture Anchor Versus Drill Tunnel Primary ACL Repair: An In Vitro Comparison of Gap Formation, ISAKOS Congress, June 7-11, 2015.

ACL Preservation: Early Results of A Novel Arthroscopic Technique of Suture Anchor Primary ACL Repair, AANA Annual Meeting, April 23-25, 2015.

Knee Injuries in Athletes: Getting Patients Back in the Game. Rosemont, IL. April 8-10, 2010. Invited Instructor.


Research Interests

Dr. DiFelice has a special interest in Ligament Preservation surgery. This includes his pioneering work on Primary ACL and PCL repairs, and Primary collateral repairs. In addition, this includes remnant preserving procedures for the knee ligaments. He has written and published extensively on these topics, and lectures both nationally and internationally on a regular basis to share his research with the orthopaedic and healthcare community.


Industry Relationships

Industry Relationships

HSS has a long history of supporting appropriate relationships with industry because they advance HSS's mission to provide the highest quality patient care, improve patient mobility, and enhance the quality of life for all, and to advance the science of orthopedic surgery, rheumatology, and their related disciplines through research and education.

Below are the healthcare industry relationships reported by Dr. DiFelice as of May 11, 2024.

  • Arthrex, Inc. - Consultant; Royalties
  • BetterHealthcare - Ownership Interest
  • HS2, LLC - Ownership Interest
  • HSS ASC Development Network, LLC - Ownership Interest
  • Joint Effort Administrative Services Organization - Ownership Interest
  • ZIMMER BIOMET - Consultant; Ownership Interest; Royalties

HSS and its physicians make this information available to patients and the public, thus creating a transparent environment for those who are interested in this information. Further, the HSS Conflicts of Interest and Commitment Policy prohibits physicians from collecting royalties on products they develop that are used on patients at HSS.

Patients should feel free to ask their HSS physicians questions about these relationships.

Dr. DiFelice in the News