Dr. Gregory Tchejeyan, M.D., INC
Contact & Location
805-495-3687
Thousand Oaks, CA 91360
Dr. Tchejeyan performs more knee replacement procedures than 61% of orthopedic surgeons in California, based on 2024 Medicare claims volume.Derived from the state ranking shown on this page: #188 of 491 ranked knee surgeons in California.
About Dr. Tchejeyan
Dr. Gregory Tchejeyan is a board-certified orthopedic surgeon practicing in Thousand Oaks, California. A Medicare provider since 2005, Dr. Tchejeyan performed 40 Medicare-verified knee replacements (#188 in California) and 22 hip replacements in the latest annual CMS data, for a combined total of 62 procedures.
In California, Dr. Tchejeyan performs near the state average in knee (40 vs 47), below the state average in hip (22 vs 41).
Dr. Tchejeyan's reported Medicare volume is split between knee replacements (40 cases) and hip replacements (22 cases).
Thousand Oaks is home to 5 orthopedic surgeons in the current Medicare dataset. Patients in the Thousand Oaks area can compare surgeon volume and procedure specialization to find the right fit for their joint replacement needs.
Dr. Tchejeyan's Medicare data spans 12 years, beginning in 2013. Volume peaked at 108 procedures in 2017 before settling at 62 in the most recent data. Changes in Medicare reporting, payer mix shifts, or practice focus adjustments can all influence year-to-year volume.
Among 6,612 knee replacement surgeons tracked nationally, Dr. Tchejeyan's 40 verified procedures is near the national average of 45.
Verified Case Volume Trends (2013-Current)
| Year | Hip Replacement | Knee Replacement |
|---|---|---|
| 2013 | 32 | 49 |
| 2014 | 36 | 27 |
| 2015 | 45 | 54 |
| 2016 | 40 | 46 |
| 2017 | 47 | 61 |
| 2018 | 47 | 53 |
| 2019 | 41 | 34 |
| 2020 | 43 | 29 |
| 2021 | 37 | 34 |
| 2022 | 44 | 35 |
| 2023 | 29 | 38 |
| 2024 | 22 | 40 |
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. Tchejeyan Compares
Procedure volume compared to the California state average.
Volume Trend Analysis
Dr. Tchejeyan's recorded volume peaked at 108 procedures in 2017 and stood at 62 in the most recent data. Year-to-year variation can reflect changes in payer mix, practice scope, or Medicare billing patterns.
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.
Recovery Timeline: Week-by-Week ExpectationsA detailed week-by-week guide covering pain levels, mobility milestones, physical therapy progression, and when to expect a return to daily activities.
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. Tchejeyan
How does Dr. Tchejeyan's procedure volume compare to other California surgeons?
Dr. Tchejeyan has performed 62 Medicare-verified joint replacement procedures. This is in line with the California average of 68 procedures per surgeon. Dr. Tchejeyan ranks #226 out of 613 orthopedic surgeons in California.
What types of joint replacement does Dr. Tchejeyan perform?
Dr. Tchejeyan's Medicare data shows procedures in knee replacement (40 cases) and hip replacement (22 cases).
Are there other orthopedic surgeons near Dr. Tchejeyan in Thousand Oaks?
Yes. There are 5 orthopedic surgeons in Thousand Oaks 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 California surgeons.
What does the Medicare data for Dr. Tchejeyan 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. Tchejeyan's total volume across all insurers at roughly 210 to 260 procedures against the 62 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. Tchejeyan's procedure volume changed over time?
Dr. Tchejeyan's Medicare-recorded volume peaked at 108 procedures in 2017 and was 62 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.
Does Dr. Tchejeyan perform more than one type of joint replacement?
Yes. Dr. Tchejeyan's Medicare data shows procedures in knee replacement (40 cases), hip replacement (22 cases). Surgeons who perform multiple joint replacement types maintain broad technical skills across different anatomical joints.
Which hospitals is Dr. Tchejeyan affiliated with?
According to CMS facility affiliation data, Dr. Tchejeyan is affiliated with Los Robles Hospital & Medical Center.
How does Dr. Tchejeyan compare to other orthopedic surgeons in Thousand Oaks?
Among the 5 orthopedic surgeons in Thousand Oaks, Dr. Tchejeyan ranks #3 by total Medicare procedure volume. Dr. Tchejeyan is among the highest-volume surgeons in Thousand Oaks.
What are the quality ratings for hospitals where Dr. Tchejeyan practices?
Los Robles Hospital & Medical Center (4 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 Thousand Oaks, California
Dr. Tchejeyan's 62 Medicare procedures are below the Thousand Oaks average of 67. The table below compares verified procedure volumes for orthopedic surgeons practicing in Thousand Oaks.
| Surgeon | Procedures | Specialties |
|---|---|---|
| Dr. Joseph Turk | 119 | Hip, Knee |
| Dr. John Delgado | 69 | Hip, Knee |
| Dr. Michael Vercillo | 61 | Knee |
| Dr. Daniel Acevedo | 26 | Shoulder |
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.