Our Team

Our Physicians

Jeffrey S. Meisles, M.D.

Dr. Meisles graduated from Rush University Medical School in 1986, and completed his Orthopedic Surgery training at Rush University Hospital in 1991. Dr. Meisles founded Orthopedic Specialists in 1991, and has been widely recognized as one of the top orthopedic surgeons in the area by U.S. News and World Report, Chicago Magazine, and West Suburban Living. He has also been voted by his peers as one of the areas top physicians, and listed in the Castle Connelly Guide “Top Doctors, Chicago Metro Area” every year since it’s initial publication more than a decade ago. Dr. Meisles is a fellow of the American Academy of Orthopedic Surgeons, and The American Association of Hip and Knee Surgeons, and has served as the chairman of surgery at Gottlieb Memorial Hospital. In addition to his clinical practice, Dr. Meisles teaches new techniques in hip and knee replacement surgery to both resident physicians and practicing orthopedic surgeons, and works as an expert consultant with several orthopedic implant manufacturers on projects involving new technology to improve the outcomes for hip and knee replacement surgery. Dr. Meisles has also been recognized by Chicago Magazine as one of Chicago’s top sports medicine doctors, and he is an expert in arthroscopic surgery. In addition, Dr. Meisles continues to treat fractures and provide general orthopedic care. Outside of work, Dr. Meisles enjoys spending time with his family, tennis, skiing and travel. He has been married to Dr. Lynn Meisles (rheumatologist) for 35 years. They have three children.

View Dr. Meisle’s Curriculum Vitae

See What My Patients Are Saying

I am a very active 61-year-old, though a couple of years ago I thought this was going to come to an end. I suddenly experienced extreme pain in my knee after years of only mild discomfort. The first treatment I received was a cortisone shot and then a gel shot. Neither one did anything to relieve the pain or help restore mobility.

That’s when I looked up Dr. Meisles. On my first visit, he thought I was a good candidate for a partial knee replacement. He explained that this was good news, as with a partial, more of my original joint would be preserved, only replacing the inside of the knee, as this was the only side that was bone on bone. He also assured me the knee would feel more like my own, I would have better flexibility, and most importantly, he predicted I would be able to resume my life passion, competitive slalom waterskiing. Now that got my attention!

He was spot-on, too. I had my partial knee replacement in September and was back on the water the following April, pain-free. I have 1 season of skiing under my belt, post knee replacement, and actively working out in preparation for this coming season, skiing at the same level as I’ve enjoyed for years. Thank You, Dr. Meisles!

Keith Erchinger

Our experience with Dr. Meisels has been a great one. My son broke his forearm in early August, he has many special needs and is medically fragile, so I was nervous about the whole process and the surgery itself. From the beginning, Dr. Meisels and his PA, Chris, were both very reassuring and willing to work with my son’s medical team from a different hospital. The surgery itself went flawlessly. My son’s recovery thus far (we are 8 weeks in) has been amazing. I would highly recommend Dr. Meisels to anyone needing surgery. I feel like he took the time to go the extra mile for my son, and his team, including all the nurses, were just phenomenal. Very glad he was the doctor we went to see after my son’s broken arm. Five stars and then some!

Cristine O'Connell

Dr. Meisles and Chris Orvino, PA did a minimally invasive anterior hip replacement on me. I am 2 weeks post-op and am doing so much better than I was prior to surgery. I was walking the day of surgery and went home the next day, able to walk upstairs as well. I no longer have the pain I had prior to surgery. They explained everything very well to me and made me feel confident that this would allow me to be able to do the activities I used to be able to do. I didn’t have a long wait to get an appointment to see them and they were able to schedule me for surgery within a few weeks. Their staff is very friendly and their office is well-run. I highly recommend them.

Mary Lou Ochalek

Physician's Assitant: Christopher M. Orvino

Chris joined the practice in 1999. He graduated from Midwestern University Physician Assistant program in June 1999. He was appointed to the adjunct faculty at Midwestern University in 2002. He has been a preceptor to numerous Physician Assistant students from Midwestern University during their orthopedic Surgery rotations. He is also involved as a mentor at the Center for Professional Excellence at Elmhurst College. As a mentor, he advises students who are pursuing a career as a Physician Assistant or other health professions. Chris is recognized as a Distinguished Fellow by the American Academy of Physician Assistant for not only his work as a Physician Assistant, but also his charity involvement in his community and for his preceptorship of future Physician Assistants. He is also recognized as a Clinical Preceptor by the American Academy of Physician Assistants for his instructions to students over the last fifteen years.

Ryon M. Hennessy, M.D.

Dr. Hennessy graduated from Rush Medical School in 1991. He completed his residency in orthopedic surgery at Rush-Presbyterian St. Luke’s Medical Center in 1996. He subsequently completed a one year fellowship in spinal surgery at Rush-Presbyterian St. Luke’s Medical Center and Chicago Shriners Hospital. In addition to the practice of general orthopedics, Dr. Hennessy has a special interest in spinal surgery and joint replacement as well as sports medicine.

View Dr. Hennessy’s Curriculum Vitae

Physician's Assistant: Jeffrey Denninger

Jeffrey is a board certified licensed Physician Assistant, who has been in practice since 2015. He graduated from Barry University in Miami Shores, Florida in 2014.

Education: University of Wisconsin-Milwaukee 2007-2011, Bachelor of Biology, Minor in Chemistry

Barry University 2012-2014 Master of Clinical Medical Science in Physician Assistant Studies

Board Certification: National Commission on Certification of Physician Assistants (NCCPA) – 2014 to present

Medical Licensure: State of Illinois Licensed Physician Assistant – 2014- present

Wisconsin Physician Assistant License

DEA registration

Basic Life Support (BLS) for the Healthcare Provider certification

Advance Cardiovascular Life Support (ACLS) certification

Professional Affiliations: American Academy of Physician Assistants (AAPA)

Daryl L. O’Connor, M.D.

Dr. Daryl L. O’Connor is a board certified orthopedic surgeon fellowship trained in sports medicine with special interest in arthroscopic surgery, cartilage transplant, and minimally invasive surgery. He graduated from Northwestern University Medical School in 1997. He completed his orthopedic surgery training at Northwestern Memorial Hospital in 2002. He subsequently completed a one year fellowship in Sports Medicine at The Orthopedic Specialty Hospital in Salt Lake City, Utah.
Dr. O’Connor treats all general orthopedic conditions. He is proficient in diagnosing and treating sports related injuries, the athlete returning to their sport healthy being his priority. Dr. O’Connor performs a broad range of surgeries including, arthroscopic repair of knee and shoulder injuries, patient specific total knee arthroplasty,and anterior total hip arthroplasty.
Since starting his practice in 2003, Dr. O’Connor has made it his priority to give individualized care to his patients, allowing the patient to feel comfortable with the direction of their care. He and his patients work together to customize a treatment plan that best fits the patient’s lifestyle and produces the best outcome for the patient.