Jonathan Berliner, MD joint replacement specialist

Jonathan L. Berliner, MD

Jonathan L. Berliner, MD, director of the ONS Outpatient Joint Replacement Center, is a board certified orthopaedic surgeon and fellowship-trained specialist in hip and knee replacement. His expertise includes muscle sparing anterior hip replacement, minimally invasive total knee and partial knee replacement, complex revision total hip and total knee replacement, computer-assisted surgery, and trauma of the lower extremity.

Dr. Berliner earned his medical degree from New York University School of Medicine, graduating with Alpha Omega Alpha (AOA) honors. He completed his residency in orthopaedic surgery at the University of California, San Francisco (UCSF), followed by a fellowship in hip and knee replacement at Hospital for Special Surgery in New York City.

Dr. Berliner is a recipient of the John Charnley Award, a national award presented annually by the Hip Society for the best innovative clinical research related to hip replacement.  He has been named a 2020 Rising Star – 40 Under 40 by the Business Council of Westchester. He has served as a visiting surgeon in Haiti and Nicaragua as a visiting surgeon and provides other volunteer medical services abroad.

Dr. Berliner’s primary focus is to develop an individualized treatment plan to help patients return to their desired activity levels and regain a fulfilling quality of life.

Please click here to request an appointment online or call 203-869-1145.


Dr. Berliner was great with our son! He was kind, professional, and put our minds at ease. We are so grateful he was the doctor that came to fix our son’s wrist! I would highly recommend Dr. Berliner!  (5 Star Review on Healthgrades)

Dr. Berliner did an anterior hip replacement on me in January and I could not be happier with the results. He is a complete professional, treating me with the upmost respect and care. He is patient, kind, competent and totally without ego. I highly recommend him. (5 Star Review on Healthgrades by J.F. of Darien, CT) September 13, 2019

I had total knee replacement in both knees by Dr. Berliner. He is an excellent surgeon and was great at explaining and guiding me through what to expect. He welcomed my questions and understood my concerns. His office staff was amazing in every situation…….Best decision I ever made. (5 Star Review on Google from A.G.)

Dr. Berliner at ONS is a superb physician and I can not recommend him highly enough. Knowledgeable and compassionate with a sense of humor. I had two anterior hip replacements in 10 months and couldn’t be happier. Run, if you can  to Dr. Berliner. (Patient comments on ONS Facebook)

With two hip replacements in 10 months I cannot say enough about Dr. Berliner and ONS. Professional, caring and superb quality of care. Would recommend Dr. Berliner and ONS to anyone with orthopedic concerns. (5 Star Review on Google from L.G.)

I came across Dr. Berliner, who has a special training to perform anterior hip replacement surgery. This surgery  shortens recovery time and it is also less painful. When I met Dr. Berliner, I knew I was in great hands. He explained everything to me in great detail and was very patient with me. I felt so comfortable that I scheduled my surgery before leaving the office. My surgery went smoothly. I was home next day. I highly recommend him! He is an exceptional orthopedic surgeon! Thank you very much. (5 Star Review on Healthgrades from Y.)

It has been 8 weeks since my hip replacement with Dr. Berliner. He gave me my pre-pain active life back. I am completely pain free and have resumed my sporting activities. I walk at least a mile per day, resumed Pilates and even started to play a little golf. Everyone is amazed with my recovery ahead of schedule. I consider Dr. Berliner an excellent and compassionate surgeon. His communication was clear and informative. His confidence helped me make the decision to undergo the procedure. He made the process less scary than I thought it would be. I am very thankful to Dr. Berliner and the staff at ONS and will gladly recommend him to others and would entrust him with another procedure if needed. (Review on ONS Facebook by A.M.)

Dr. Jonathan Berliner did anterior double hip replacement on my husband and we are both so impressed! His compassion and professionalism is amazing! We are both so grateful for his work and expertise! Thank you Dr Berliner! (5 Star Review on Facebook from D.S.B)

Dr. Berliner is a very nice man who answered all of my many questions prior to and after my surgery. It has been 4 weeks since my anterior full hip replacement and I am doing very well. I was pleased with his bedside manor, he had no arrogance and I never felt rushed at an appointment. Most of all, with Dr. Berliner’s muscle sparing anterior technique, I was able to do a full squat with no pain only 8 days after my surgery and I was twirling my cane like Charlie Chaplin on my daily walk! (5 Star Review on Healthgrades from L. in New Canaan, CT)

I was having severe left hip pain and went to Dr. Berliner for a second opinion. I ended up having him do my anterior hip replacement this past January, and I am so pleased. He is professional and compassionate, and an excellent surgeon. I was a nervous wreck since I never had surgery before, nor had I ever even been in a hospital in my 67 years of living! He is wonderful, bottom line. I need a knee replaced too, and he will be doing that when the time comes! (5 Star review on Healthgrades from P.P. in Norwalk)

At 34, I was young to need a hip replacement, but needed one regardless. I am very grateful to have found Dr. Berliner. He handled a complex case swiftly and adeptly, with a calm confidence unparalleled in other surgeons.

The post-operative pain was negligible compared to the amount of pain I was in pre-op. Within a week, I was walking with a cane, something I hadn’t been able to do during the 5 months prior.  Evident of his people skills, he even handled my post-operative anxiety about complications occurring like a pro, alleviating any concerns.

I sent the post-op images to a relative overseas who is also an orthopedic surgeon. He said Dr. Berliner did “brilliant work.” – I can only agree.  Thank you. (L.D.)

Dr. Berliner is absolutely the best! I did much research before having my total anterior hip replacement and because he is young and starting his practice, I could not find much information on him. I took a chance because I had a good feeling and he did an outstanding job with my surgery. He was very present and available and didn’t have the doctor ego where he wouldn’t answer questions etc. etc. He was nothing short of incredible. I’m so thankful to him and all the team at ONS. (5 Star Review on Healthgrades by M.F. of Danbury, CT)

When I first came into your office, I was nine months post-operative from a  total knee replacement from a doctor in Florida. He did a horrible job. I was +70/65 bend. Just horrible. I met Dr. Berliner after he came highly recommended. He changed my life on 12/15/17. He did a total revision on my right knee. I am now 8 days post operative and bending 80 already and -5. I am so blessed for him.  It was a very tough surgery and he did an amazing job.  (J.B., 5 Star Reveiw on ONS Facebook page)

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Is Outpatient Joint Replacement Right for You?

Joint Replacement Symposium

Modern Trends in Joint Replacement, 60 mins.

Trends in Joint Replacement 30 mins.


Watch Dr. Berliner’s presentation on Anterior Total Hip Replacement and Rapid Recovery:

Dr. Berliner discusses Anterior Hip Replacement with Dr. Lou Bisogni on White Plains Public Television:


Alpha Omega Alpha Honor Society
American Academy of Orthopaedic Surgeons
American Association of Hip and Knee Surgeons
American Board of Orthopaedic Surgery, Board Certified

California Orthopaedic Association


2020 Rising Star – 40 Under 40, Business Council of Westchester

The John Charnley Award, The Hip Society 2015
for best innovative research encompassing important advances in the management of hip disorders.


Iona Prep Football Team Physician, New Rochelle, NY,  2018 season
San Francisco Marathon
University of California, San Francisco PlaySafe Marathon
San Francisco Rock’ n Roll Half Marathon


Hospital Lenin Fonseca,  Nicaragua
CRUDEM Foundation, Haiti
New York City Free Clinic, New York


Berliner JL, Esposito CI, Miller TT, Padgett DE, Mayman DJ, Jerabek SA. What preoperative factors predict postoperative sitting pelvic position one year following total hip arthroplasty? Bone Joint J. 2018 Oct;100-B(10):1289-1296. PMID: 30295534

Rueckl K, Sculco PK, Berliner JL, Cross MB, Koch C, Boettner F. Fracture risk of tapered modular revision stems: a failure analysis. Arthroplast Today. 2017 Dec 21;4(3):300-305. PMID: 30186909

Berliner JL, Ortiz PA, Lee YY, Miller TT, Westrich GH. Venous Hemodynamics After Total Hip Arthroplasty: A Comparison Between Portable vs Stationary Pneumatic Compression Devices and the Effect of Body Position. J Arthroplasty. 2018 Jan;33(1):162-166. PMID 28927565

Wong SE, Zhang AL, Berliner JL, Ma CB, Feeley BT. Preoperative patient-reported scores can predict postoperative outcomes after shoulder arthroplasty. J Shoulder Elbow Surg. 2016 Jun;25(6):913-9. PMID


Berliner JL, Brodke DJ, Chan V, SooHoo NF, Bozic KJ. Can Preoperative Patient-reported Outcome Measures Be Used to Predict Meaningful Improvement in Function After TKA? Clin Orthop Relat Res. 2016 Mar 8. PMID 26956248

Berliner JL, Brodke DJ, Chan V, SooHoo NF, Bozic KJ. John Charnley Award: Preoperative Patient- Reported Outcome Measures Predict Clinically Meaningful Improvement in Function after THA. Clin Orthop Relat Res. 2016 Feb;474(2):321-9. doi: 10.1007/s11999-015-4350-6. PMID 26201420

Berliner JL, Regalado-Magdos A, Ma CB, Feeley BT. Biomechanics of Reverse Total Shoulder Arthroplasty. J Shoulder Elbow Surg. 2015 Jan;24(1):150-160. doi: 10.1016/j.jse.2014.08.003. PMID  25441574

Elliott RE, Bollo RJ, Berliner JL, Silverberg A, Carlson C, Geller EB, Barr WB, Devinsky O, Doyle WK. Anterior temporal lobectomy with amygdalohippocampectomy for mesial temporal sclerosis: predictors of long-term seizure control. Neurosurg. 2013 Aug;119(2):261-72. doi: 10.3171/2013.4.JNS121829. PMID 23706057

Berliner JL, Verma K, Lonner BS, Penn PU, Bharucha NJ. Discriminative validity of the Scoliosis Research Society 22 questionnaire among five curve-severity subgroups of adolescents with idiopathic scoliosis. Spine J. 2013 Feb;13(2):127-33. doi: 10.1016/j.spinee.2012.10.025. PMID 23218828

Bollo RJ, Berliner JL, Fischer I, Miles DK, Thiele EA, Zagzag D, Weiner HL. Extraventricular subependymal giant cell tumor in a child with tuberous sclerosis complex. Neurosurg Pediatr. 2009 Jul;4(1):85-90. doi: 10.3171/2009.3.PEDS08225. PMID 19569916


Berliner JL, Esposito CI, Miller TT, Padgett DE, Mayman DJ, Jerabek SA. Hip flexion increases and spine flexion decreases from standing to sitting position 1 year after patients undergo total hip arthroplasty. Paper Presentation at the American Academy of Orthopaedic Surgeons (AAOS) Annual Meeting, New Orleans LA, 3/2018

Berliner JL, Esposito CI, Miller TT, Padgett DE, Mayman DJ, Jerabek SA. Hip flexion increases and spine flexion decreases from standing to sitting position 1 year after patients undergo total hip arthroplasty. Abstract presented at the American Academy of Hip and Knee Surgeons (AAHKS) Annual Meeting, Dallas TX, 11/2017

Berliner JL, Brodke D, Chan V, Bozic KJ. Patient Reported Outcome Measures as a Tool for Surgical Appropriateness in Total Hip Replacement. Paper presentation presented at the American Academy of Orthopaedic Surgeons (AAOS) Annual Meeting, Las Vegas NV, 3/2015

Berliner JL, Zhang AL, Lansdown DA, Ma CB, Feeley BT. Prevalence Of Rotator Cuff Atrophy And Fatty Infiltration In Patients With Glenohumeral Osteoarthritis. Abstract to be presented at the American Academy of Orthopaedic Surgeons (AAOS) Annual Meeting, Las Vegas NV, 3/2015.

Berliner JL, Brodke D, Chan V, Bozic KJ. Patient Reported Outcome Measures as a Tool for Surgical Appropriateness in Total Knee Replacement. Abstract to be presented at the 2014 American Association of Hip and Knee Surgeons Annual Meeting, Houston TX, 11/2014

Verma K, Berliner JL, Lonner BS Does the SRS-22 Correlate with Curve Severity in Adolescent Idiopathic Scoliosis? An Age and Gender Matched Comparison. Poster presented at the 17th International Meeting on Advanced Spine Techniques (IMAST), 7/2010


Berliner JL, Haas SB – Extra-articular tibial deformity: Correction with the Implant – Complex Cases in Total Knee Arthroplasty: A Compendium of Current Techniques, 2018

THA: Posterior Approach – AAOS Advanced Reconstruction Hip 2. Collaborating with Dr. Thomas Vail 2016

Revision THA: Component Removal – AAOS Advanced Reconstruction Hip 2. Collaborating with Dr. Kevin Bozic, 2016


Reviewed 2019

Kevin Choo, MD

Kevin J. Choo, MD

Kevin J. Choo, MD, is an orthopedic surgeon who specializes in primary hip and knee replacement for the treatment of degenerative osteoarthritis, inflammatory arthritis, avascular necrosis, hip dysplasia, and post-traumatic arthrosis.  He is fellowship-trained in direct anterior hip replacement, use of computer- and robotic-assisted technology, and partial knee replacement. His clinical interest also includes revision hip and knee surgery for the treatment of failed joint replacement due to infection, loosening, or recurrent dislocation.

Dr. Choo earned his medical degree from the University of Chicago and completed his internship and residency at UCSF (University of California- San Francisco). He received  fellowship training in Adult Reconstruction and Joint Replacement at the Rothman Institute in Philadelphia, PA.  Dr. Choo has presented and published on such topics as the biology of bone healing, the reduction of opioid use after orthopedic surgery, periprosthetic joint infection management, and partial joint replacement. Dr. Choo was named an Emerging Leader by the American Orthopaedic Association (AOA). He is a reviewer for the Journal of the American Association of Orthopaedic Surgeons (JAAOS) and the Journal of Orthopaedic Trauma (JOT)

Please click here to schedule an appointment online or call (203) 869-1145


From realizing it was time for a knee replacement to researching a knee replacement doctor, a friend spoke to me about Dr. Choo from ONS. When I saw that he took my insurance it was a go. I paid close attention to the team Dr. Choo has. They are so informative and caring. I had such help from them setting into place what help I would need at home. Dr. Choo was so confident in letting me know what a better quality of life I would have. It has been 5 months since the surgery. Dr. Choo gave me the confidence to endure the icing of the knee and the exercising is so important rest and fluids. To stay focused on the healing process. Thank you Dr. Choo and his team. God bless you all. (5 Star Review on Healthgrades from DS)

Knowledgeable, professional and caring. Thoroughly explained my condition to me. (5 Star Review on Healthgrades)

The office seemed very clean and well run, everyone was nice, Dr Choo explained everything clearly, was friendly, and I left feeling confident in what needed to be done. (5 Star Review on Healthgrades)

Dr Choo employs the anterior method of performing hip replacements and, two weeks after my procedure, I am very pleased indeed to give him the highest possible rating. It’s relevant to note that I am 86 years old. My experience has been remarkable. The very same day of my operation, the nurses and therapist at Greenwich Hospital got me on my feet with a walker and I was able to walk down a corridor. Courtesy of Dr Choo’s skill, plus no doubt the effect of blockers, recommended medications and occasional ice – packs, my recovery has been almost pain-free. Dr Choo exhibits a highly confident and pleasant and professional manner – entirely justified in my experience. (5 Star Review on Google from DM)
I, too, am two weeks into a full hip replacement performed by the amazing Dr. Choo who was absolutely perfect!! His explanations, patience, humility, respect, and most importantly his immense skill and knowledge in this area were exactly what I needed to get through this hip replacement, following the multiple spinal fusions I’ve also had at ONS. He collaborated with my spine surgeon early on and set a course that was perfect in planning and execution. I couldn’t be happier or recommend Dr. Choo more highly — he is fantastic in every way. (5 Star Review on Healthgrades from P.K.)
I am two weeks into a full hip replacement. Dr. Choo could not have been better. He explained all procedures clearly and thoroughly, used a front entry incision, and a spinal and a sedative instead of full anesthesia so I recovered quickly after the surgery. Dr. Choo invited questions on my part and listened and answered all of them in terms I could understand. After the surgery he checked on me three times in the hospital and called me at home the day after to check on me. Everybody associated with ONS was helpful and caring. All appointments were made quickly and were not rushed. I am not medically knowledgeable – but I did due diligence looking into the details of full hip replacement. Dr. Choo is state-of-the-art in his work, and a kind and caring professional. I can recommend him with the highest possible rating.  (5 Star Review on Healthgrades from M.G.)

Excellent-responsive and interested. (5 Star Review on Healthgrades)

My 83 year old mother-in-law fell in April and broke her hip which required emergency surgery. This was made even more tragic since it was during the height of Covid-19. Dr.Choo, who we could only meet by phone, was extremely kind, compassionate and professional. He addressed all of our questions and concerns and really put our family at ease during this difficult time. At our request and without hesitation, Dr. Choo called a friend of ours, a surgeon at HSS, to go over the case prior to surgery. I don’t know many doctors who would have agreed to do that. The surgery went extremely well and I am happy to report that my mother-in-law is doing fabulous! Thank you Dr. Choo!

I waited three years in pain and at the end of 2019 I was in so much pain that I was dragging my right leg, the pain was incredible. I went to see Dr. Choo, he made me feel that he can give me my life back and he did. I suffered for 3 years because I was afraid. Today I’m so happy. On valentine’s day 2020, I got a new hip and the surgery was great, the pain management was great and I didn’t end up needing extra strong medicine. I was determined to get better and I was walking right after surgery. Thank you to Dr Choo and all his collegues, I have my life back and I can do anything I want with no pain. (5 Star Review on Healthgrades from G.I.))

I knew I probably needed a total hip replacement for several years, but I was terrified.
After a trip to the ER when attempting to ride my bike, I realized it was time. I was very impressed with Dr. Choo’s credentials and once I met him, I knew I had the surgeon I needed. He explained the procedure and what to expect really well, and that so helped to put me at ease. Dr Choo and his team are incredible. I am six months post -op and I can’t believe how great I feel. Thank you, Dr. Choo! (5 Star Review on Google)

If it were possible, I would give Dr. Choo 6 stars. My emergency broken hip surgery was perfectly executed by Dr Choo. He was a gift to me from heaven. His kindness, understanding, professionalism/knowledge and skill was the perfect package. I’m very grateful he was on call for my accident. (5 Star Review on Healthgrades from M.S.)
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Understanding Knee Pain

Joint Replacement Symposium


American Orthopaedic Association (AOA), Emerging Leader  – UCSF

American Orthopaedic Association (AOA), C.McCollister Evarts Leadership  – UCSF

Health Volunteers Overseas (HVO) Traveling Fellowship – UCSF (Managua, Nicaragua)

Scholarship and Discovery Research Grant – University of Chicago

Howard Hughes Medical Institute (HHMI) Research Grant – Stanford University


Yazdi, H, Choo KJ, Restrepo C, Hammad M, Sherman M, Parvizi J. Short Term Results of Triathlon Cementless versus Cemented Primary Total Knee Arthroplasty. The Knee. 2020. (accepted, pending publication)

Choo KJ, Austin M, Parvizi J.  Irrigation and debridement, modular exchange and implant retention for acute periprosthetic infection after total knee arthroplasty.  Journal of Bone and Joint Surgery (JBJS) Essent Surg Tech. 2019. 

Choo KJ, Grace TR, Khanna K, Barry J, Hansen EN. A Goal-directed Quality Improvement Initiative to Reduce Opioid Prescriptions After Orthopaedic Procedures. JAAOS Global Research & Reviews. 2019 Sept 17;3(9)

Grace TR, Choo KJ, Patterson J, Khanna K, Feeley, BT, Zhang AL. A Review of Inpatient Opioid Consumption and Discharge Prescription Patterns after Orthopaedic Procedures.  Journal of the American Academy of Orthopaedic Surgeons. 2019.

Grace TR, Khanna K, Choo KJ, Croci R, Feeley BT, Ma CB, Zhang AL.   The Influence of Preoperative Opioid Use on Inpatient Opioid Requirements and Discharge Medication Prescriptions After Primary Shoulder Arthroplasty.  J Shoulder Elbow Surg. 2018; Apr 24. pii S1058-2746(18)30173-

Wong K, Burns R, Mohan R, Yi PH, Choo KJ. Variability in Conflict of Interest Disclosures by Physicians Presenting Trauma  Research. World J Orthop. 2017; Apr18;8(4):329-335

Choo KJ, Yi PH, Burns R, Mohan R, Wong K. Variable Reporting by Authors Presenting Arthroplasty Research at Multiple  Annual Conferences. J Arthroplasty. 2017; 32:315-219

Wang Z, Tran M, Bhatia N, Hsing A, Chen C, LaRussa M, Fattakhov E, Rshidi V, Hang KY, Choo KJ, Nie X, Mathy J, Longaker MT, Dauskardt R, Helms J, Yang GP. DEL1 Knockout Mice Developed More Severe Osteoarthritis Associated with Increased Susceptibility of Chondrocytes to Apoptosis. PLoS One.  2016 Aug 9;11(8)

Horst PK, Choo K, Bharucha N, Vail TP.  Graduates of Orthopaedic Residency Training are Increasingly Subspecialized: A Review of the American Board of Orthopaedic Surgery Part II Database. J Bone Joint Surg Am. 2015 May 20;97(10): 869-7

Morshed S, Choo KJ, Kandemir U, Kaiser SP. Internal Fixation of Posterior Pelvic Ring Injuries Using Iliosacral Screws in the Dysmorphic Upper Sacrum. JBJS Essent Surg Tech. 2015 Feb 11; 5 (1): e3

Choo KJ, Arora VM, Barach P, Johnson JK, Farnan JM. How Do Supervising Physicians Decide to Entrust Residents with Unsupervised Tasks? A Qualitative Analysis. J Hosp Med. 2014 Mar;9(3):169-75

Choo KJ, Morshed S. Postoperative Complications After Repair of Tibial Plateau Fractures. J Knee Surg. 2014 Feb;27(1):11-9

Guzman R, De Los Angeles A, Choo K, Gaeta X, Cote J, Cheshier S, Steinberg GK. Intra-carotid Delivery of CD49d FACS Sorted Neural Stem Cells Enhances Angiogenesis and Improves Functional Outcome After Stroke. Stroke 2008 (39);527-72


Choo KJ, Lonner JH. (2019) Treating Patellofemoral Osteoarthritis with Unicompartmental and Bicompartmental Knee Arthroplasty.  Unicompartmental Knee Arthroplasty: Indications, Surgical Techniques and Complications. New York, NY: Springer Publishing. [textbook chapter]


Choo KJ, Malkani K, Cooper AM, Yazdi H, Parvizi J. Dual-Mobility Bearings and Constrained Liners in Revision Total Hip Arthroscopy: A Comparison of Outcomes. American Academy of Orthopaedic Surgeons (AAOS) National Meeting (2020)

Grace T, Khanna K, Choo K, Zhang A. Does Tailoring Discharge Opioid Regimens to Inpatient Use After Orthopaedic Procedures Affect Refill Rates. Western Orthopaedic Association Annual Meeting, Snowmass, CO. 2018 August 2.

Choo KJ, Sing D, Hansen E. Psychological Distress after Diagnosis and Treatment for Prosthetic Joint Infection.  UCSF Abbott Society Scientific Program (2018)

Choo KJ. Conflict of Interest in Orthopaedic Surgery.  UCSF Dept. Orthopaedic Surgery Grand Rounds (2017)

Choo KJ, Morshed S, Wustrack RL, O’Donnell RJ. Femoral Pathologic Fracture in Morbidly Obese Patient Managed with External Fixation and Compressive Osseointegration.  Advances in Orthopaedic Osseointegration Conference (2015)

Choo KJ, Arora VM, Barach P, Julie JK, Farnan JM. When Do Supervising Physicians Decide to Entrust Residents With Unsupervised Tasks? A Qualitative Study. Society of General Internal Medicine- National Conference (2012)

Choo KJ, Farnan JM, Barach P, Arora VM. Factors that Determine Entrustment, Supervision, and Autonomy of Housestaff During Inpatient Medicine Rotations: A Qualitative Study. Society of General Internal Medicine- Midwest Conference (2011)

Choo KJ, Wang Z, Longaker MT, Yang GP. Histomorphometric Analysis of Tibial Bone Fracture in Del-1 Knockout Mice. American College of Surgeons Clinical Congress (2009)


Choo, KJ, Rajaravivarma, R, Hozack W. Effect of Femoral Head Material on Head-to-Trunnion Impaction Motion and Taper Stability.  Orthopaedic Research Society (ORS) Annual Meeting (2020)

Choo KJ, Farnan JM, Barach P, Arora VM. Factors that Determine Entrustment, Supervision, and Autonomy of Housestaff During Inpatient Medicine Rotations: A Qualitative Study. Midwestern Hospitalist Medicine Conference (2011)

Choo KJ, Taxy J, Blair EA. Salivary Gland Mucoepidermoid Carcinoma: An Institutional Review. American College of Surgeons Clinical Congress (2010).

Frank A. Ennis, MD

Frank Ennis, MD, specializes in hip and knee replacement, hip arthroscopy, complex revision arthroplasty of the hip and knee, and treatment of complications from hip fractures. He is fellowship-trained in adult reconstructive surgery. Dr. Ennis is a staff orthopedic surgeon at Greenwich Hospital and was among the first orthopedic surgeons in the New York Metropolitan area to do computer-assisted surgery for total knee and hip replacement. This cutting edge technique uses computerized navigation to guide the surgeon for improved accuracy in joint replacement surgery.

Further, after completing undergraduate studies at Yale University and post-baccalaureate pre-medical studies at Harvard University, he graduated from Duke University School of Medicine and completed his residency at Yale University Department of Orthopaedic Surgery. Additionally, Dr. Ennis completed Fellowship training in adult reconstructive surgery at New England Baptist Hospital in Boston,  MA.

Continue reading “Frank A. Ennis, MD”

Tim Greene, MD

Tim Greene, MD is an orthopedic surgeon who is fellowship trained in sports medicine and hip arthroscopy, a technique that has revolutionized the treatment of various hip problems. Dr. Greene graduated Princeton University and earned his medical degree at the Medical College of Georgia. He practiced his residency in orthopedics at Emory University and served as associate team physician to the athletic teams at Georgia Tech.

Dr. Greene completed fellowship training at the Steadman Hawkins Clinic in Vail, Colorado under the direction of Dr. Marc Philippon. While there, he served as associate team physician for the U.S. Ski Team.

Dr. Greene’s interest in sports medicine derives from his ongoing personal interest in sports. While at Princeton University, he was team captain in varsity football and earned numerous awards for outstanding athletic achievement.

Please click here to schedule an appointment.


I am a Director of Critical Care and a seasoned RN as well. Dr. Green is top notch- I send everyone to him that I can. He is humane, highly comprehensible, takes his time, explains things well and is clinically excellent! The surgery center he uses in Stamford was excellent, clean, great staff and everyone was in the same page! (5 Star Review on Google from L.J-K.)
I can’t say enough positive things about Dr. Greene. I am a professional tennis player and had a literal and figurative pain in the butt when I played. Other symptoms included recurrent groin “pulls” and glute strains and deep achy pain across my low back. No one could properly diagnose the underlying cause until I saw Dr. Greene, who diagnosed me with labral tears and impingement (FAI) in both hips. My symptoms did not perfectly align with those typical of FAI, but he believed this to be the cause and we decided it was best to operate given my urgency to get back to the tour. He basically did a rim trim, osteoplasty and labral repair on both sides (6 weeks apart). This decision had me so anxious, and now I sit here 3.5 months after my second hip surgery, Indian-style… sorry, it’s 2020… “cross-legged” with no pain whatsoever! I am back to playing tennis and weight training – already doing things I previously could not. I couldn’t be happier with my decision to use Dr. Greene over other prominent surgeons in NYC and CT. He is by far the most trustworthy, communicative, personable (and probably most skilled) of the four surgeons I saw… he also has a great sense of humor, despite being a Falcons fan. (5 Star Review on Google from S.K.)

I thought it was important to send a note to someone at ONS about Dr. Greene and Alicia Hirscht, DPT. I have been treating with Dr. Greene for a torn abductor tendon and other hip issues since December. I started PT in Stamford under Alicia Hirscht. I would easily recommend either practitioner to a family member.

Dr. Greene’s communication was clear and concise when weighing treatment options.  PT Hirscht made room in her schedule for me and took the time and effort to get me up and playing tennis again. They are both true professionals and showed an incredible amount of patience working with me to recover from my chronic injuries.

Keep up the excellent work and hiring practices. (note from patient P.Y.)

Unbelievable experience after many years and many doctors and feeling incredibly defeated I randomly saw ads for this place and figured what do I have to loose. After one visit, Dr Heftler figured it out. By this point I’d already had 6 MRIs from other doctors, medications, injections to no avail. He called me with the news himself not a nurse. I couldn’t be more impressed and grateful. I couldn’t be more grateful to him after years of debilitating pain someone finally figured it out. He then referred me to Dr Greene for surgery, another fantastic experience. All in all I will ONLY ago here for any orthopedic needs and send everyone else here. PT employees are fabulous, nurses and desk staff always made a pleasant experience. Highly recommend. (5 Star Review on Yelp from E.C.)


I am a Director of Critical Care and a seasoned RN as well. Dr. Greene is top notch- I send everyone to him that I can. He is humane, highly comprehensible, takes his time, explains things well and is clinically excellent! The surgery center he uses in Stamford was excellent, clean, great staff and everyone was in the same page! (5 Star Review on Google from L.J.K)

Just took my daughter to an appointment with Dr. Tim Greene after a disappointing appointment at another orthopedic office not affiliated with ONS. If I was able to…I would give Dr. Greene and ONS a rating much higher than 5 Stars.

I could not have been more impressed with every aspect of my daughters care. The offices were clean & the staff was extremely welcoming & friendly. We were brought into the exam room early which in most cases doesn’t happen at a doctors office.

Dr. Greene came in and listened to our concerns/issues, examined our daughter and was in absolutely no rush to move on to his next patient. He answered all of our questions, explained the X-Rays to us and expressed genuine care for her injury and treatment. He made sure we understood everything and had a plan going forward.

We also had concerns about how to schedule MRI’s and other testing. He immediately sent a note to someone on his team to help us. We sat with Jessica who took her time and made all the arrangements for us. She also followed up the next day with info we needed to make sure everything was done right.

About 3 hours after our appt. with Dr. Greene my wife and I had a question we forgot to ask. We called the office after Dr. Greene had left but a message was taken and I was assured either Dr. Greene or his assistant would call back the next day. They called in the morning and answered everything for us.

Being an athlete and also a firefighter I have seen a lot of orthopedic surgeons and have been to many practices and I can say this was one of the best experiences I have had. In my opinion they go way above the standard of care. I would highly recommend Dr. Greene to anyone who may need orthopedic care. (5 Star Review from Google from P.F.)

I have been coming here for at least 15 years and have seen a variety of amazing doctors … Dr. Greene being a favorite in our household for years and would trust him with everything.  Recently I broke my elbow and was sent to Dr. Vadasdi.  She was amazing! Great with surgery and aftercare. Very compassionate throughout the whole process! Thank you ONS for getting me through everything! (E.D.)

The ONS team is like family. Dr.Greene is my hip doctor and he is excellent!! I feel that I am in great hands from the moment I walk in the doors.. Thank you ONS. (T.A.)

Dr. Greene: It has been 6 weeks since you mended my fractured left clavicle and I continue to make progress in my recovery. I estimate that my range of motion in the shoulder is close to 90% and I am beginning to cautiously build strength in the muscles affected by my injury. I wish you a wonderful Thanksgiving, and this year I am especially grateful for having such a great orthopedist as you. – (R.G.)


Doctors, Nurses, Therapists, and support staff: This is a big THANK YOU for all the expert and attentive care you extended towards my recovery from a broken pelvis and elbow after a spill on black ice in December ’09. Let everyone know, there is Zumba after broken bones heal. I received excellent care at Greenwich Hospital, with elbow surgery by Dr. Greene (yay for titanium). Each of you as a part of this “total team” took me from being in excruciating pain and bedridden to no pain and full function and then some! – (L.A.)


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Brian Kavanagh, MD

Brian F. Kavanagh, MD

Joint replacement specialist Brian Kavanagh, MD is a staff orthopedic physician at Greenwich Hospital where he has performed more than 6000 surgeries over the past 25 years. Board-certified by the American Board of Orthopaedic Surgery, Dr. Kavanagh graduated Princeton University and attended University of Connecticut School of Medicine. His internship and residency were performed at the Mayo Clinic, Mayo Graduate School of Medicine in Rochester, Minnesota. He served on the full-time faculty at the Mayo Graduate School of Medicine for seven years and on the teaching staff at Yale University School of Medicine in New Haven for five years. In addition, he is a former consultant to the Department of Orthopedics at the Mayo Clinic, where he specialized in hip and knee reconstruction. He was also an instructor in the hip and knee total joint fellowship program.

Further, Dr. Kavanagh has authored and edited numerous articles and book chapters and serves on the editorial staff of the Journal of Arthroscopy and the publication, Clinical Orthopaedics and Related Research. Also, he is an examiner for the American Board of Orthopaedic Surgery and a member of several specialty orthopedic societies.

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