#8 Knee
#16 Hip

Dr. John Diana, M.D.

Orthopedic Surgery
326 procedures 5 hospitals Napa, CA
Latest available Medicare data — updated April 2026
Rising Star Top 10% Nationally
Knee replacement recovery kit Ice machines, mobility aids, bathroom safety — under $50 essentials
National Comparison by Procedure
Hip 118 vs 36 avg (4,526 surgeons)
Knee 208 vs 45 avg (6,720 surgeons)

Dr. John Diana is a board-certified orthopedic surgeon practicing in Napa, California. A Medicare provider since 2006, Dr. Diana has performed 208 Medicare-verified knee replacements (#8 in California) and 118 hip replacements, for a combined total of 326 procedures.

In California, Dr. Diana performs well above average in knee (208 vs 45 avg), well above average in hip (118 vs 41 avg).

Dr. Diana's reported Medicare volume is split between knee replacements (208 cases) and hip replacements (118 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 11 years of data. Over that period, recorded procedure volume increased from 246 to 326 in the most recent data, a 33% increase. This sustained growth reflects an expanding joint replacement practice.

Among 6,720 knee replacement surgeons tracked nationally, Dr. Diana's 208 verified procedures is more than 4x the national average of 45, ranking #52 nationally.

Verified Medicare Cases

Knee Replacement
208 verified cases
#8 in California
Hip Replacement
118 verified cases
#16 in California
Estimated total: 880 – 990 procedures (all insurers)
Based on Medicare FFS representing 33–37% of national joint replacement volume
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.

Hip Very High
118 Avg: 41
Knee Very High
208 Avg: 45
Dr. Diana California Average

Contact & Location

Phone: 707-254-7117
3273 Claremont Way
Napa, CA 94558
NPI: 1649297540
Credentials: M.D.
Active Medicare provider (NPI verified)
20 years of practice experience
Licensed M.D.
Licensed surgical specialist
Board-certified orthopedic surgeon
Contact information available
Find Practice on Google Maps

Volume Trend Analysis

Dr. Diana's Medicare-recorded procedure volume has trended upward over 11 years, increasing 33% from 246 procedures in 2013 to 326 in the most recent data.

Years of Data 11
2023 Volume 326
Peak Volume 389 (2019)
Trend Growing

Hospital Affiliations & Quality

H
Adventist Health St Helena
★★★★☆
Saint Helena, CA
Similar to national avg
H
Sonoma Valley Hospital
★☆☆☆☆
Sonoma, CA
Low case volume
H
Providence Queen Of The Valley Medical Center
★★★★☆
Napa, CA
Low case volume
H
Adventist Health Clearlake
★☆☆☆☆
Clearlake, CA
H
Adventist Health Mendocino Coast
★☆☆☆☆
Fort Bragg, CA

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.

Knee Replacement Recovery Overview

Recovery timelines vary by patient, but here is a general overview of what to expect after knee replacement surgery:

Week 1-2 Walking with assistive device. Knee bending exercises begin immediately. Ice therapy and elevation for swelling control.
Week 3-6 Increased range of motion (target 90 degrees). Walking longer distances. Physical therapy intensifies with strengthening exercises.
Week 7-12 Most patients walk without assistive devices. Resume driving and desk work. Continue PT for strength and flexibility.
Month 4-6 Near-full recovery. Resume most recreational activities. Some swelling and stiffness may persist but continues improving.

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 326 Medicare-verified joint replacement procedures. This is more than 5x the California average of 65 procedures per surgeon. Dr. Diana ranks #8 out of 608 orthopedic surgeons in California.

What types of joint replacement does Dr. Diana perform?

Dr. Diana's Medicare data shows procedures in knee replacement (208 cases) and hip replacement (118 cases).

How experienced is Dr. Diana with knee replacement surgery?

Dr. Diana ranks #8 in California for knee replacement with 208 Medicare-verified procedures. This high ranking among 608 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 326 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 326 in the most recent data, a 33% increase over 11 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 (208 cases), hip replacement (118 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 326 Medicare procedures are above the Napa average of 228. The table below compares verified procedure volumes for orthopedic surgeons practicing in Napa.

SurgeonProceduresSpecialties
Dr. Michael Caravelli 130 Hip, Knee

Patient Reviews & Ratings

OrthoProcedures.com focuses on verified Medicare procedure data. For patient reviews, ratings, and appointment scheduling, visit these trusted platforms:

These links lead to third-party websites. OrthoProcedures.com is not affiliated with these platforms and cannot verify the accuracy of reviews.

Cite This Data

APA: OrthoProcedures. (2026). Dr. John Diana, M.D. -- Orthopedic Surgeon Profile. Retrieved from https://orthoprocedures.com/surgeons/ca/dr-john-diana-napa.html

Link: https://orthoprocedures.com/surgeons/ca/dr-john-diana-napa.html

Data source: CMS Medicare Part B Provider Utilization & Payment Data. Full methodology | Open Data API

Important: Rankings are based solely on Medicare procedure volume and do not reflect quality of care, patient outcomes, or procedures covered by private insurance. This data represents approximately one-third to 40% of all joint replacement procedures nationwide. Always consult with healthcare providers to make informed decisions about your care.