Dr. Brad Zwahlen, M.D.
Contact & Location
Berkeley, CA 94705
Dr. Brad Zwahlen is a board-certified orthopedic surgeon practicing in Berkeley, California. Dr. Zwahlen has performed 12 Medicare-verified knee replacements, ranking #471 in California.
In California, Dr. Zwahlen performs below average in knee (12 vs 47 avg).
Dr. Zwahlen's Medicare data shows a focused knee replacement practice with 12 verified procedures. Surgeons who concentrate on a single procedure type often develop deep procedural expertise, though total practice volume may include additional procedures not captured in Medicare fee-for-service data.
Berkeley is home to 4 orthopedic surgeons in the current Medicare dataset. Patients in the Berkeley area can compare surgeon volume and procedure specialization to find the right fit for their joint replacement needs.
Dr. Zwahlen's Medicare data spans 6 years, beginning in 2014. Volume peaked at 21 procedures in 2014 before settling at 12 in the most recent data. Changes in Medicare reporting, payer mix shifts, or practice focus adjustments can all influence year-to-year volume.
Dr. Zwahlen's 12 knee replacement procedures is below the national average of 45 among 6,599 surgeons. Medicare data captures roughly a third of all joint replacements, so actual volume is likely higher.
Verified Case Volume Trends (2013-Current)
Verified Medicare Cases
How is this estimated?
Medicare Part B fee-for-service claims represent approximately 33–37% of all joint replacements performed nationally (source: CMS data, AJRR). This range estimates the surgeon's total practice volume across all payers. The verified Medicare count above is the definitive, audited figure.
How Dr. Zwahlen Compares
Procedure volume compared to the California state average.
Volume Trend Analysis
Dr. Zwahlen's recorded volume peaked at 21 procedures in 2014 and stood at 12 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.
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. Zwahlen
How does Dr. Zwahlen's procedure volume compare to other California surgeons?
Dr. Zwahlen has performed 12 Medicare-verified joint replacement procedures. The California average is 68 procedures per surgeon. Medicare data captures roughly one-third of all joint replacements, so total volume may be higher. Dr. Zwahlen ranks #586 out of 613 orthopedic surgeons in California.
What types of joint replacement does Dr. Zwahlen perform?
Dr. Zwahlen's reported Medicare volume is focused on knee replacement, with 12 verified procedures. Some surgeons choose to concentrate on a single joint type to build deep procedural expertise.
Are there other orthopedic surgeons near Dr. Zwahlen in Berkeley?
Yes. There are 4 orthopedic surgeons in Berkeley 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. Zwahlen represent?
The procedure counts shown are based on the most recent Medicare Part B fee-for-service claims data, published by the Centers for Medicare and Medicaid Services (CMS). This captures approximately 33–37% of all joint replacements performed nationally. Dr. Zwahlen's total practice volume — including private insurance and Medicare Advantage patients — is likely higher than the 12 procedures shown here.
Has Dr. Zwahlen's procedure volume changed over time?
Dr. Zwahlen's Medicare-recorded volume peaked at 21 procedures in 2014 and was 12 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. Zwahlen affiliated with?
According to CMS facility affiliation data, Dr. Zwahlen is affiliated with Alta Bates Summit Medical Center - Alta Bates Camp.
How does Dr. Zwahlen compare to other orthopedic surgeons in Berkeley?
Among the 4 orthopedic surgeons in Berkeley, Dr. Zwahlen ranks #4 by total Medicare procedure volume. The highest-volume surgeon in Berkeley has 86 verified Medicare procedures.
What are the quality ratings for hospitals where Dr. Zwahlen practices?
Alta Bates Summit Medical Center - Alta Bates Camp (3 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 Berkeley, California
Dr. Zwahlen's 12 Medicare procedures are below the Berkeley average of 41. The table below compares verified procedure volumes for orthopedic surgeons practicing in Berkeley.
| Surgeon | Procedures | Specialties |
|---|---|---|
| Dr. Christopher Chen | 86 | Hip, Knee |
| Dr. Robert Eppley | 51 | Knee, Shoulder |
| Dr. Jerold Kaplan | 15 | Hip |
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.