Dr. John Diana, M.D.
Contact & Location
Napa, CA 94558
Dr. John Diana is a board-certified orthopedic surgeon practicing in Napa, California. A Medicare provider since 2006, Dr. Diana has performed 207 Medicare-verified knee replacements (#6 in California) and 122 hip replacements, for a combined total of 329 procedures.
In California, Dr. Diana performs well above average in knee (207 vs 47 avg), well above average in hip (122 vs 41 avg).
Dr. Diana's reported Medicare volume is split between knee replacements (207 cases) and hip replacements (122 cases).
Beyond general orthopedic surgery, Dr. Diana holds additional credentials in Sports Medicine and Orthopaedic Trauma, reflecting subspecialty training that may benefit patients with complex joint conditions.
Napa is home to 2 orthopedic surgeons in the current Medicare dataset. Patients in the Napa area can compare surgeon volume and procedure specialization to find the right fit for their joint replacement needs.
Medicare records for Dr. Diana extend back to 2013, covering 12 years of data. Over that period, recorded procedure volume increased from 246 to 329 in the most recent data, a 34% increase. This sustained growth reflects an expanding joint replacement practice.
Among 6,599 knee replacement surgeons tracked nationally, Dr. Diana's 207 verified procedures is more than 4x the national average of 45, ranking #54 nationally.
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. Diana Compares
Procedure volume compared to the California state average.
Volume Trend Analysis
Dr. Diana's Medicare-recorded procedure volume has trended upward over 12 years, increasing 34% from 246 procedures in 2013 to 329 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.
Nutrition and Recovery After Joint ReplacementHow protein intake, anti-inflammatory foods, hydration, and targeted supplements support bone healing and tissue repair after surgery.
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. Diana
How does Dr. Diana's procedure volume compare to other California surgeons?
Dr. Diana has performed 329 Medicare-verified joint replacement procedures. This is more than 4x the California average of 68 procedures per surgeon. Dr. Diana ranks #8 out of 613 orthopedic surgeons in California.
What types of joint replacement does Dr. Diana perform?
Dr. Diana's Medicare data shows procedures in knee replacement (207 cases) and hip replacement (122 cases).
How experienced is Dr. Diana with knee replacement surgery?
Dr. Diana ranks #6 in California for knee replacement with 207 Medicare-verified procedures. This high ranking among 613 state surgeons indicates significant experience with this specific procedure.
Are there other orthopedic surgeons near Dr. Diana in Napa?
Yes. There are 2 orthopedic surgeons in Napa 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. Diana 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. Diana's total practice volume — including private insurance and Medicare Advantage patients — is likely higher than the 329 procedures shown here.
Has Dr. Diana's procedure volume changed over time?
Yes. Dr. Diana's Medicare-recorded volume has increased from 246 procedures in 2013 to 329 in the most recent data, a 34% increase over 12 years. This upward trend suggests an expanding joint replacement practice. Peak volume was 389 procedures in 2019.
Does Dr. Diana perform more than one type of joint replacement?
Yes. Dr. Diana's Medicare data shows procedures in knee replacement (207 cases), hip replacement (122 cases). Surgeons who perform multiple joint replacement types maintain broad technical skills across different anatomical joints.
Which hospitals is Dr. Diana affiliated with?
According to CMS facility affiliation data, Dr. Diana is affiliated with Adventist Health St Helena, Sonoma Valley Hospital, Providence Queen Of The Valley Medical Center, Adventist Health Clearlake, Adventist Health Mendocino Coast.
What are the quality ratings for hospitals where Dr. Diana practices?
Adventist Health St Helena (4 out of 5 CMS stars, hip/knee complication rate similar to national average); Sonoma Valley Hospital (1 out of 5 CMS stars, insufficient case volume for complication rate comparison); Providence Queen Of The Valley Medical Center (4 out of 5 CMS stars, 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 Napa, California
Dr. Diana's 329 Medicare procedures are above the Napa average of 224. The table below compares verified procedure volumes for orthopedic surgeons practicing in Napa.
| Surgeon | Procedures | Specialties |
|---|---|---|
| Dr. Michael Caravelli | 118 | Hip, 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.