Beyond his medical achievements, Dr. Klion is a seasoned endurance athlete with accomplishments that include 15 Ironman triathlons, 15 marathons, and numerous ultra-distance running and biking races, such as the Zion 100 Mile Ultra Marathon. He serves as the Medical Director for esteemed events like the New York City Triathlon and Toughman Triathlon, holding a key role on the Medical Advisory Board of USA Triathlon.

In collaboration with world-renowned triathlon coach Troy Jacobson, Dr. Klion co-authored "Triathlon Anatomy," a guide empowering triathletes to optimize strength, power, speed, and endurance while preventing injury. Together with Dr. James Capozzi, he developed "BodyworksMD," a physician-guided home rehabilitation series. Dr. Klion is also a founding member of TRIARQ Health, an initiative fostering collaboration among patients, physicians, physical therapists, and healthcare professionals to elevate standards in clinical and service excellence through education and research.


Recognized by Castle Connolly as a Top Doctor from 2016-2023

Appeared in NY Magazine as a Top Doctor in 2017, 2021, 2022, and 2023

Recognized by Super Doctors in 2013, 2015, and 2016

Board Certifications

Orthopedic Surgery (ABOS)


  • Director of Orthopedics, St. Barnabas Hospital
  • Clinical Instructor, Mount Sinai Department of Orthopedics
  • Attending Physician, Lenox Hill Hospital
  • Partner, Midtown Surgery Center

Clinical Areas of Interest

  • Sports Medicine
  • Arthroscopy of the shoulder, hip, knee, and ankle
  • Shoulder dislocations, labral tears, and rotator cuff tears
  • Knee meniscus and ligament injuries
  • Hip labral tear
  • Fractures around ankles, knees, and shoulders

Practice Locations

Westchester, NY

222 Westchester Ave
Suite 101
West Harrison, NY 10604
(914) 849-7897


Book Online


Mark Klion has been helping triathletes optimize their performance and stay injury free for decades. I've raced side by side with Dr. Klion at the Ironman in Kona, Hawaii. I've also visited his Manhattan office for treatments and advice that kept me at the top of my game.

Christopher Bergland, World-class Endurance Athlete who Broke a Guinness World Record for Treadmill Running

Having combined experience of more than 50 years of training and treating endurance athletes of every level, Dr. Mark Klion and Jonathan Cane (co-author of Triathlon Academy) know exactly what it takes to achieve optimal performance.

Victoria Brumfield, Chief of Staff for USA Triathlon

Dr. Klion and his staff are exceptional. My son broke his arm and because it was his first break we had to randomly select an Ortho. Luckily we picked this one. The office is run very efficiently with a friendly front desk crew. X-ray was done immediately and then right in to see Dr. Klion. I anticipated a long wait, but Dr. Klion's staff were a well oiled machine. We were in and out in no time.

Dr. Klion was not rushed and had a sense of humor while still very professional. We’ve had two additional follow-ups which were easy to schedule through the online patient portal.

Great communication, friendly and knowledgeable staff, and a healthy arm after a break. I’d highly recommend this practice.


Dr. Klion did an excellent job on my meniscus tear in my knee. He was averse to immediately recommend surgery and had me do physical therapy for 6+ months. When it became clear surgery was necessary, he quickly scheduled me, surgery went very smoothly, great recovery and he closely monitored my rehab. Surgery was mid-November and I ran a trail ultra-marathon by early May. Now I'm 2 years out and can hardly remember which knee he fixed.