Dr. John Brennan, M.D.
Contact & Location
631-689-6698
East Setauket, NY 11733
Dr. Brennan performs more knee replacement procedures than 45% of orthopedic surgeons in New York, based on 2024 Medicare claims volume.Derived from the state ranking shown on this page: #147 of 269 ranked knee surgeons in New York.
About Dr. Brennan
Practice. Dr. John Brennan is a board-certified orthopedic surgeon practicing in East Setauket, New York. The latest annual CMS data records 27 knee replacements and 11 hip replacements, 38 procedures in all. That is #147 in New York for knee replacement.
Trend. Medicare records run from 2015 to 2024, 10 years. Volume rose from 12 procedures a year to 38, up 217%.
National context. Among 6,612 knee replacement surgeons tracked nationally, 27 procedures is below the national average of 45. Medicare covers part of all joint replacements, so true volume is likely higher.
Local context. East Setauket has 7 orthopedic surgeons in the current Medicare data. Comparing volume and procedure mix across them is one way to narrow a shortlist.
Verified Case Volume Trends (2013-Current)
| Year | Hip Replacement | Knee Replacement |
|---|---|---|
| 2013 | 0 | 0 |
| 2014 | 0 | 0 |
| 2015 | 12 | 0 |
| 2016 | 0 | 18 |
| 2017 | 0 | 11 |
| 2018 | 12 | 15 |
| 2019 | 22 | 15 |
| 2020 | 11 | 0 |
| 2021 | 14 | 18 |
| 2022 | 0 | 22 |
| 2023 | 0 | 32 |
| 2024 | 11 | 27 |
Verified Medicare Cases
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, 25% to 33% for hip 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. Brennan Compares
Procedure volume compared to the New York state average.
Volume Trend Analysis
Dr. Brennan's Medicare-recorded procedure volume has trended upward over 10 years, increasing 217% from 12 procedures in 2015 to 38 in the most recent data.
Hospital Affiliations & Quality
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:
An overview of current surgical approaches including robotic-assisted and minimally invasive techniques, implant options, and expected outcomes.
Questions to Ask Your Surgeon Before Joint ReplacementA practical checklist of questions covering experience, technique, hospital choice, and recovery expectations to discuss during your surgical consultation.
Home Safety: Creating Your Recovery SanctuaryRoom-by-room modifications, equipment recommendations, and fall-prevention strategies to prepare your home for a safe post-surgical recovery.
Outpatient Joint Replacement: A Medicare GuideHow outpatient joint replacement works under Medicare, including eligibility criteria, cost differences, and what to expect with same-day discharge.
Knee Replacement Recovery Overview
Recovery timelines vary by patient, but here is a general overview of what to expect after knee replacement surgery:
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. Brennan
How does Dr. Brennan's procedure volume compare to other New York surgeons?
Dr. Brennan has performed 38 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. Brennan ranks #202 out of 334 orthopedic surgeons in New York.
What types of joint replacement does Dr. Brennan perform?
Dr. Brennan's Medicare data shows procedures in knee replacement (27 cases) and hip replacement (11 cases).
Are there other orthopedic surgeons near Dr. Brennan in East Setauket?
Yes. There are 7 orthopedic surgeons in East Setauket 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. Brennan 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, 25% to 33% for hip replacement, which puts Dr. Brennan's total volume across all insurers at roughly 130 to 160 procedures against the 38 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. Brennan's procedure volume changed over time?
Yes. Dr. Brennan's Medicare-recorded volume has increased from 12 procedures in 2015 to 38 in the most recent data, a 217% increase over 10 years. This upward trend suggests an expanding joint replacement practice. Peak volume was 38 procedures in 2024.
Does Dr. Brennan perform more than one type of joint replacement?
Yes. Dr. Brennan's Medicare data shows procedures in knee replacement (27 cases), hip replacement (11 cases). Surgeons who perform multiple joint replacement types maintain broad technical skills across different anatomical joints.
Which hospitals is Dr. Brennan affiliated with?
According to CMS facility affiliation data, Dr. Brennan is affiliated with St Charles Hospital, Stony Brook University Hospital.
How does Dr. Brennan compare to other orthopedic surgeons in East Setauket?
Among the 7 orthopedic surgeons in East Setauket, Dr. Brennan ranks #6 by total Medicare procedure volume. The highest-volume surgeon in East Setauket has 308 verified Medicare procedures.
What are the quality ratings for hospitals where Dr. Brennan practices?
St Charles Hospital (4 out of 5 CMS stars, hip/knee complication rate similar to national average); Stony Brook University Hospital (4 out of 5 CMS stars, hip/knee complication rate better than national average). These are hospital-level quality metrics from CMS Hospital Compare and do not reflect individual surgeon outcomes.
Other Orthopedic Surgeons in East Setauket, New York
Dr. Brennan's 38 Medicare procedures are below the East Setauket average of 121. The table below compares verified procedure volumes for orthopedic surgeons practicing in East Setauket.
| Surgeon | Procedures | Specialties |
|---|---|---|
| Dr. James Nicholson | 308 | Hip, Knee |
| Dr. Douglas Petraco | 205 | Hip, Knee |
| Dr. Fazel Khan | 98 | Hip, Knee |
| Dr. Christopher Mileto | 91 | Hip, Knee, Shoulder |
| Dr. Gregory Mallo | 80 | Shoulder |
| Dr. Gregory Minutillo | 28 | 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.