Dr. John Mariani, DO

Orthopedic Surgery
64 procedures 2 hospitals Sewell, NJ
Latest available Medicare data — updated April 2026
Growing Volume

Contact & Location

Phone: 609-267-9400
Practice phone listed in the NPI registry
570 Egg Harbor Rd
Sewell, NJ 08080
NPI: 1811006885
Credentials: DO
Active Medicare provider (NPI verified)
20 years of practice experience
Licensed DO
Licensed surgical specialist
Board-certified orthopedic surgeon
Contact information available
Find Practice on Google Maps
Knee replacement recovery kit Ice machines, mobility aids, bathroom safety, all under $50
National Comparison by Procedure
Knee 64 vs 45 avg (6,599 surgeons)

Dr. John Mariani is a board-certified orthopedic surgeon practicing in Sewell, New Jersey. A Medicare provider since 2006, Dr. Mariani has performed 64 Medicare-verified knee replacements, ranking #39 in New Jersey.

In New Jersey, Dr. Mariani performs near average in knee (64 vs 54 avg).

Dr. Mariani's Medicare data shows a focused knee replacement practice with 64 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.

Sewell is home to 3 orthopedic surgeons in the current Medicare dataset. Patients in the Sewell area can compare surgeon volume and procedure specialization to find the right fit for their joint replacement needs.

Medicare records for Dr. Mariani extend back to 2013, covering 12 years of data. Over that period, recorded procedure volume increased from 49 to 64 in the most recent data, a 31% increase. This sustained growth reflects an expanding joint replacement practice.

Among 6,599 knee replacement surgeons tracked nationally, Dr. Mariani's 64 verified procedures is above the national average of 45.

Verified Medicare Cases

Knee Replacement
64 verified cases
#39 in New Jersey
Estimated total: 170 – 190 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. Mariani Compares

Procedure volume compared to the New Jersey state average.

Knee Average
64 Avg: 54
Dr. Mariani New Jersey Average

Volume Trend Analysis

Dr. Mariani's Medicare-recorded procedure volume has trended upward over 12 years, increasing 31% from 49 procedures in 2013 to 64 in the most recent data.

Years of Data 12
2024 Volume 64
Peak Volume 80 (2019)
Trend Growing

Hospital Affiliations & Quality

H
Jefferson Stratford Hospital
2/5
Stratford, NJ
Similar to national avg
H
West Jersey Hospital
3/5
Voorhees, NJ
Similar to national avg

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:

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. Mariani

How does Dr. Mariani's procedure volume compare to other New Jersey surgeons?

Dr. Mariani has performed 64 Medicare-verified joint replacement procedures. This is in line with the New Jersey average of 72 procedures per surgeon. Dr. Mariani ranks #67 out of 184 orthopedic surgeons in New Jersey.

What types of joint replacement does Dr. Mariani perform?

Dr. Mariani's reported Medicare volume is focused on knee replacement, with 64 verified procedures. Some surgeons choose to concentrate on a single joint type to build deep procedural expertise.

Are there other orthopedic surgeons near Dr. Mariani in Sewell?

Yes. There are 3 orthopedic surgeons in Sewell 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 New Jersey surgeons.

What does the Medicare data for Dr. Mariani 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. Mariani's total practice volume — including private insurance and Medicare Advantage patients — is likely higher than the 64 procedures shown here.

Has Dr. Mariani's procedure volume changed over time?

Yes. Dr. Mariani's Medicare-recorded volume has increased from 49 procedures in 2013 to 64 in the most recent data, a 31% increase over 12 years. This upward trend suggests an expanding joint replacement practice. Peak volume was 80 procedures in 2019.

Which hospitals is Dr. Mariani affiliated with?

According to CMS facility affiliation data, Dr. Mariani is affiliated with Jefferson Stratford Hospital, West Jersey Hospital.

How does Dr. Mariani compare to other orthopedic surgeons in Sewell?

Among the 3 orthopedic surgeons in Sewell, Dr. Mariani ranks #2 by total Medicare procedure volume. Dr. Mariani is among the highest-volume surgeons in Sewell.

What are the quality ratings for hospitals where Dr. Mariani practices?

Jefferson Stratford Hospital (2 out of 5 CMS stars, hip/knee complication rate similar to national average); West Jersey Hospital (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 Sewell, New Jersey

Dr. Mariani's 64 Medicare procedures are above the Sewell average of 51. The table below compares verified procedure volumes for orthopedic surgeons practicing in Sewell.

SurgeonProceduresSpecialties
Dr. Luke Austin 69 Shoulder
Dr. Jeffrey Murray 19 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.

Cite This Data

APA: OrthoProcedures. (2026). Dr. John Mariani, DO -- Orthopedic Surgeon Profile. Retrieved from https://orthoprocedures.com/surgeons/nj/dr-john-mariani-sewell.html

Link: https://orthoprocedures.com/surgeons/nj/dr-john-mariani-sewell.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.