Dr. Robert Kohen, M.D.
Contact & Location
586-558-2870
Warren, MI 48092
Dr. Kohen performs more knee replacement procedures than 85% of orthopedic surgeons in Michigan, based on 2024 Medicare claims volume.Derived from the state ranking shown on this page: #30 of 202 ranked knee surgeons in Michigan.
About Dr. Kohen
Practice. Dr. Robert Kohen is a board-certified orthopedic surgeon practicing in Warren, Michigan. The latest annual CMS data records 56 knee replacements and 17 shoulder replacements, 73 procedures in all. That is #30 in Michigan for knee replacement. A Medicare provider since 2007.
Trend. Medicare records run from 2014 to 2024, 11 years. Volume rose from 22 procedures a year to 73, up 232%.
National context. Among 6,612 knee replacement surgeons tracked nationally, 56 procedures is above the national average of 45.
Local context. Warren has 5 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 | Knee Replacement | Shoulder Replacement |
|---|---|---|
| 2013 | 0 | 0 |
| 2014 | 22 | 0 |
| 2015 | 22 | 0 |
| 2016 | 29 | 0 |
| 2017 | 30 | 21 |
| 2018 | 53 | 18 |
| 2019 | 34 | 23 |
| 2020 | 32 | 15 |
| 2021 | 36 | 17 |
| 2022 | 41 | 21 |
| 2023 | 45 | 19 |
| 2024 | 56 | 17 |
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, 29% to 37% for shoulder 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. Kohen Compares
Procedure volume compared to the Michigan state average.
Volume Trend Analysis
Dr. Kohen's Medicare-recorded procedure volume has trended upward over 11 years, increasing 232% from 22 procedures in 2014 to 73 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.
Prehabilitation: Preparing Your Body for SurgeryEvidence-based exercises and lifestyle adjustments that can improve surgical outcomes and speed recovery when started weeks before your procedure.
Pain Management After Joint ReplacementA comprehensive guide to managing post-surgical pain through medication, physical therapy, cold therapy, and non-pharmacological strategies.
Medicare Bundled Payment Programs for Joint ReplacementHow bundled payment models affect your joint replacement costs and care coordination, and what it means for hospital and surgeon selection.
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. Kohen
How does Dr. Kohen's procedure volume compare to other Michigan surgeons?
Dr. Kohen has performed 73 Medicare-verified joint replacement procedures. This is in line with the Michigan average of 49 procedures per surgeon. Dr. Kohen ranks #50 out of 256 orthopedic surgeons in Michigan.
What types of joint replacement does Dr. Kohen perform?
Dr. Kohen's Medicare data shows procedures in knee replacement (56 cases) and shoulder replacement (17 cases).
Are there other orthopedic surgeons near Dr. Kohen in Warren?
Yes. There are 5 orthopedic surgeons in Warren 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 Michigan surgeons.
What does the Medicare data for Dr. Kohen 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, 29% to 37% for shoulder replacement, which puts Dr. Kohen's total volume across all insurers at roughly 250 to 300 procedures against the 73 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. Kohen's procedure volume changed over time?
Yes. Dr. Kohen's Medicare-recorded volume has increased from 22 procedures in 2014 to 73 in the most recent data, a 232% increase over 11 years. This upward trend suggests an expanding joint replacement practice. Peak volume was 73 procedures in 2024.
Does Dr. Kohen perform more than one type of joint replacement?
Yes. Dr. Kohen's Medicare data shows procedures in knee replacement (56 cases), shoulder replacement (17 cases). Surgeons who perform multiple joint replacement types maintain broad technical skills across different anatomical joints.
Which hospitals is Dr. Kohen affiliated with?
According to CMS facility affiliation data, Dr. Kohen is affiliated with Trinity Health Oakland Hospital, Corewell Health William Beaumont University Hospit, Corewell Health Farmington Hills Hospital, Corewell Health Beaumont Troy Hospital.
How does Dr. Kohen compare to other orthopedic surgeons in Warren?
Among the 5 orthopedic surgeons in Warren, Dr. Kohen ranks #1 by total Medicare procedure volume. Dr. Kohen has the highest verified Medicare volume in the city.
What are the quality ratings for hospitals where Dr. Kohen practices?
Trinity Health Oakland Hospital (2 out of 5 CMS stars, hip/knee complication rate similar to national average); Corewell Health William Beaumont University Hospit (3 out of 5 CMS stars, hip/knee complication rate similar to national average); Corewell Health Farmington Hills Hospital (2 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 Warren, Michigan
Dr. Kohen's 73 Medicare procedures are above the Warren average of 33. The table below compares verified procedure volumes for orthopedic surgeons practicing in Warren.
| Surgeon | Procedures | Specialties |
|---|---|---|
| Dr. Jeffrey Mendelson | 33 | Hip, Knee |
| Dr. David Mendelson | 31 | Knee |
| Dr. Ronald Rook | 15 | Knee |
| Dr. Steven Plomaritis | 12 | 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.