Dr. Joseph Assenmacher, M.D.
Contact & Location
419-690-8811
Oregon, OH 43616
Dr. Assenmacher performs more knee replacement procedures than 91% of orthopedic surgeons in Ohio, based on 2024 Medicare claims volume.Derived from the state ranking shown on this page: #25 of 305 ranked knee surgeons in Ohio.
About Dr. Assenmacher
Dr. Joseph Assenmacher is a board-certified orthopedic surgeon practicing in Oregon, Ohio. A Medicare provider since 2005, Dr. Assenmacher completed 92 knee replacements (#25 in Ohio), 23 shoulder replacements, and 15 hip replacements in the latest annual CMS data, totaling 130 Medicare-verified procedures.
In Ohio, Dr. Assenmacher performs well above the state average in knee (92 vs 41), below the state average in shoulder (23 vs 29), below the state average in hip (15 vs 32).
Dr. Assenmacher performs all three major joint replacement procedures (hip, knee, and shoulder), indicating a broad scope of orthopedic practice. The largest share is knee replacements (92 cases), followed by shoulder replacements (23) and hip replacements (15).
Oregon is home to 5 orthopedic surgeons in the current Medicare dataset. Patients in the Oregon area can compare surgeon volume and procedure specialization to find the right fit for their joint replacement needs.
Medicare records for Dr. Assenmacher extend back to 2013, covering 12 years of data. Over that period, recorded procedure volume increased from 80 to 130 in the most recent data, a 63% increase. This sustained growth reflects an expanding joint replacement practice.
Among 6,612 knee replacement surgeons tracked nationally, Dr. Assenmacher's 92 verified procedures is more than 2x the national average of 45.
Verified Case Volume Trends (2013-Current)
| Year | Hip Replacement | Knee Replacement | Shoulder Replacement |
|---|---|---|---|
| 2013 | 14 | 50 | 16 |
| 2014 | 14 | 45 | 0 |
| 2015 | 12 | 80 | 13 |
| 2016 | 24 | 45 | 15 |
| 2017 | 22 | 66 | 15 |
| 2018 | 18 | 78 | 12 |
| 2019 | 26 | 60 | 11 |
| 2020 | 19 | 50 | 0 |
| 2021 | 16 | 65 | 19 |
| 2022 | 23 | 74 | 24 |
| 2023 | 29 | 85 | 28 |
| 2024 | 15 | 92 | 23 |
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, 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. Assenmacher Compares
Procedure volume compared to the Ohio state average.
Volume Trend Analysis
Dr. Assenmacher's Medicare-recorded procedure volume has trended upward over 12 years, increasing 63% from 80 procedures in 2013 to 130 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.
What to Expect on the Day of SurgeryA step-by-step walkthrough of your surgical day, from pre-op preparation through anesthesia, the procedure itself, and the first hours of recovery.
Rehabilitation Roadmap: Your Complete Recovery GuideA structured physical therapy progression from the first post-op exercises through full strength and mobility restoration over 3 to 6 months.
Medicare Coverage for Joint ReplacementWhat Medicare Part A and Part B cover for joint replacement surgery, including hospital stays, surgeon fees, anesthesia, and physical therapy.
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. Assenmacher
How does Dr. Assenmacher's procedure volume compare to other Ohio surgeons?
Dr. Assenmacher has performed 130 Medicare-verified joint replacement procedures. This is more than 2x the Ohio average of 59 procedures per surgeon. Dr. Assenmacher ranks #35 out of 370 orthopedic surgeons in Ohio.
What types of joint replacement does Dr. Assenmacher perform?
Dr. Assenmacher performs all three major joint replacement procedures: knee replacement (92 cases), shoulder replacement (23 cases), hip replacement (15 cases). This breadth indicates a comprehensive orthopedic joint replacement practice.
Are there other orthopedic surgeons near Dr. Assenmacher in Oregon?
Yes. There are 5 orthopedic surgeons in Oregon 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 Ohio surgeons.
What does the Medicare data for Dr. Assenmacher 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, 25% to 33% for hip replacement, which puts Dr. Assenmacher's total volume across all insurers at roughly 440 to 540 procedures against the 130 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. Assenmacher's procedure volume changed over time?
Yes. Dr. Assenmacher's Medicare-recorded volume has increased from 80 procedures in 2013 to 130 in the most recent data, a 63% increase over 12 years. This upward trend suggests an expanding joint replacement practice. Peak volume was 142 procedures in 2023.
Does Dr. Assenmacher perform more than one type of joint replacement?
Yes. Dr. Assenmacher's Medicare data shows procedures in knee replacement (92 cases), shoulder replacement (23 cases), hip replacement (15 cases). Performing all three major joint replacements places Dr. Assenmacher among the 5% of orthopedic surgeons nationally who cover hip, knee, and shoulder arthroplasty.
Which hospitals is Dr. Assenmacher affiliated with?
According to CMS facility affiliation data, Dr. Assenmacher is affiliated with Bay Park Community Hospital, Toledo Hospital The, Magruder Hospital, Memorial Hospital, Wood County Hospital.
How does Dr. Assenmacher compare to other orthopedic surgeons in Oregon?
Among the 5 orthopedic surgeons in Oregon, Dr. Assenmacher ranks #1 by total Medicare procedure volume. Dr. Assenmacher has the highest verified Medicare volume in the city.
What are the quality ratings for hospitals where Dr. Assenmacher practices?
Bay Park Community Hospital (3 out of 5 CMS stars, insufficient case volume for complication rate comparison); Toledo Hospital The (4 out of 5 CMS stars, hip/knee complication rate similar to national average); Magruder Hospital (insufficient case volume for complication rate comparison). These are hospital-level quality metrics from CMS Hospital Compare and do not reflect individual surgeon outcomes.
Other Orthopedic Surgeons in Oregon, Ohio
Dr. Assenmacher's 130 Medicare procedures are above the Oregon average of 65. The table below compares verified procedure volumes for orthopedic surgeons practicing in Oregon.
| Surgeon | Procedures | Specialties |
|---|---|---|
| Dr. Craig Assenmacher | 74 | Hip, Knee, Shoulder |
| Dr. Bradley Morse | 60 | Hip, Knee |
| Dr. Benjamin Assenmacher | 44 | Hip, Knee |
| Dr. Enesi Momoh | 16 | 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.