Dr. Stephen O'brien, ORTHOPAEDIC SURGEON

Specialist

16 procedures1 hospitalNew York, NYUpdated May 2026

Contact & Location

212-606-1011
Phone: 212-606-1011
Practice phone listed in the NPI registry
535 E 70th St
New York, NY 10021
Current practice address per the CMS NPPES registry (self-reported to the registry, last updated March 2021). Registry checked August 2026.
NPI: 1720002686
Credentials: ORTHOPAEDIC SURGEON
Active Medicare provider (NPI verified)
20 years of practice experience
Licensed Orthopaedic Surgeon
Contact information available
Find Practice on Google Maps
National Comparison by Procedure
Knee 16 vs 45 national avg 0.4x
avg

Compared with 6,612 knee surgeons in the 2024 Medicare dataset.

Dr. O'brien performs more knee replacement procedures than 15% of orthopedic surgeons in New York, based on 2024 Medicare claims volume.Derived from the state ranking shown on this page: #227 of 269 ranked knee surgeons in New York.

About Dr. O'brien

Practice. Dr. Stephen O'brien is a board-certified orthopedic surgeon practicing in New York, New York. The latest annual CMS data records 16 knee replacements. That is #227 in New York for knee replacement. A Medicare provider since 2006.

Trend. Medicare records run from 2013 to 2024, 12 years. Volume peaked at 41 in 2013 and stands at 16 now. Reporting changes and payer mix can both move that number.

National context. Among 6,612 knee replacement surgeons tracked nationally, 16 procedures is below the national average of 45. Medicare covers part of all joint replacements, so true volume is likely higher.

Local context. New York has 84 orthopedic surgeons in the current Medicare data. Comparing volume and procedure mix across them is one way to narrow a shortlist.

Verified Medicare Cases

Knee Replacement
16 verified cases
#227 in New York
Estimated 2024 total: 60 – 70 procedures (all insurers)
Medicare fee-for-service share of national volume in 2024: 23% to 28% for knee replacement
How is this estimated?

Medicare Part B fee-for-service claims are one payer stream among several, and the share they represent differs by procedure. In 2024 it was 23% to 28% for knee replacement. Each verified count above is divided by its own procedure's range, and the results are added, to estimate total practice volume across all payers. The verified Medicare count is the definitive, audited figure; this is a range derived from published national volume projections, not a measurement, and an individual practice can sit well outside it: how these ranges are derived, and their sources.

How Dr. O'brien Compares

Procedure volume compared to the New York state average.

Knee Below Avg
16 Avg: 47
Dr. O'brien New York Average

Volume Trend Analysis

Dr. O'brien's recorded volume peaked at 41 procedures in 2013 and stood at 16 in the most recent data. Year-to-year variation can reflect changes in payer mix, practice scope, or Medicare billing patterns.

Years of Data 12
2024 Volume 16
Peak Volume 41 (2013)
Trend Declining

Hospital Affiliations & Quality

H
Hospital For Special Surgery
5/5
New York, NY
Similar to national avg

Quality ratings and complication rates are hospital-level metrics from CMS Hospital Compare and do not reflect individual surgeon performance. Star ratings updated quarterly. Complication data covers a rolling 3-year period.

Patient Resources: Preparing for Knee Replacement

If you are considering knee replacement surgery, these evidence-based guides can help you prepare and recover:

Knee Replacement Recovery Overview

Recovery timelines vary by patient, but here is a general overview of what to expect after knee replacement surgery:

Week 1-2 Walking with assistive device. Knee bending exercises begin immediately. Ice therapy and elevation for swelling control.
Week 3-6 Increased range of motion (target 90 degrees). Walking longer distances. Physical therapy intensifies with strengthening exercises.
Week 7-12 Most patients walk without assistive devices. Resume driving and desk work. Continue PT for strength and flexibility.
Month 4-6 Near-full recovery. Resume most recreational activities. Some swelling and stiffness may persist but continues improving.

Individual recovery varies based on overall health, age, and adherence to physical therapy. View full knee replacement recovery guide and product recommendations

Frequently Asked Questions About Dr. O'brien

How does Dr. O'brien's procedure volume compare to other New York surgeons?

Dr. O'brien has performed 16 Medicare-verified joint replacement procedures. The New York average is 69 procedures per surgeon. Medicare data captures roughly one-third of all joint replacements, so total volume may be higher. Dr. O'brien ranks #287 out of 334 orthopedic surgeons in New York.

What types of joint replacement does Dr. O'brien perform?

Dr. O'brien's reported Medicare volume is focused on knee replacement, with 16 verified procedures. Some surgeons choose to concentrate on a single joint type to build deep procedural expertise.

Are there other orthopedic surgeons near Dr. O'brien in New York?

Yes. There are 84 orthopedic surgeons in New York in the current Medicare dataset. Patients can compare procedure volumes and specializations to choose the surgeon who best fits their needs. Use the state page to view all New York surgeons.

What does the Medicare data for Dr. O'brien represent?

The procedure counts shown are based on 2024 Medicare Part B fee-for-service claims data, published by the Centers for Medicare and Medicaid Services (CMS). Medicare fee-for-service is only one payer stream, and the share of national volume it represents differs by procedure. In 2024 the share was 23% to 28% for knee replacement, which puts Dr. O'brien's total volume across all insurers at roughly 60 to 70 procedures against the 16 verified here. Those shares are derived from published national volume projections rather than quoted from a single publication, and they are estimates with real uncertainty. The OrthoProcedures methodology page shows the full derivation, the sources, and the limits at orthoprocedures.com/data-methodology.html.

Has Dr. O'brien's procedure volume changed over time?

Dr. O'brien's Medicare-recorded volume peaked at 41 procedures in 2013 and was 16 in the most recent data. Volume fluctuations can reflect changes in payer mix, practice focus, or Medicare reporting rather than a change in overall surgical activity.

Which hospitals is Dr. O'brien affiliated with?

According to CMS facility affiliation data, Dr. O'brien is affiliated with Hospital For Special Surgery.

How does Dr. O'brien compare to other orthopedic surgeons in New York?

Among the 84 orthopedic surgeons in New York, Dr. O'brien ranks #75 by total Medicare procedure volume. The highest-volume surgeon in New York has 343 verified Medicare procedures.

What are the quality ratings for hospitals where Dr. O'brien practices?

Hospital For Special Surgery (5 out of 5 CMS stars, hip/knee complication rate similar to national average). These are hospital-level quality metrics from CMS Hospital Compare and do not reflect individual surgeon outcomes.

Other Orthopedic Surgeons in New York, New York

Dr. O'brien's 16 Medicare procedures are below the New York average of 261. The table below compares verified procedure volumes for orthopedic surgeons practicing in New York.

SurgeonProceduresSpecialties
Dr. Brian Chalmers 343 Hip, Knee
Dr. Jason Blevins 322 Hip, Knee
Dr. Eytan Debbi 322 Hip, Knee
Dr. Amar Ranawat 318 Hip, Knee
Dr. Geoffrey Westrich 276 Hip, Knee
Dr. Elizabeth Gausden 229 Hip, Knee

Patient Resources & Verification

Research reviews, verify credentials, and check official quality data through these trusted sources:

Medicare Care Compare and NPI Registry are official U.S. government sources. Google reviews reflect user-submitted feedback. OrthoProcedures.com does not verify the accuracy of third-party review content.

Cite This Data

APA: OrthoProcedures. (2026). Dr. Stephen O'brien, ORTHOPAEDIC SURGEON -- Orthopedic Surgeon Profile. Retrieved from https://orthoprocedures.com/surgeons/ny/dr-stephen-obrien-new-york.html

Link: https://orthoprocedures.com/surgeons/ny/dr-stephen-obrien-new-york.html

Data source: CMS Medicare Part B Provider Utilization & Payment Data. Full methodology | Open Data API

Important: Rankings are based solely on Medicare procedure volume and do not reflect quality of care, patient outcomes, or procedures covered by private insurance. This data represents approximately one-third to 40% of all joint replacement procedures nationwide. Always consult with healthcare providers to make informed decisions about your care.