Dr. Donald Longjohn, M.D.

Orthopedic Surgery

46 procedures5 hospitalsLos Angeles, CAUpdated May 2026

Contact & Location

323-442-5860
Phone: 323-442-5860
Practice phone listed in the NPI registry
1520 San Pablo St, #2000
Los Angeles, CA 90033
Current practice address per the CMS NPPES registry (self-reported to the registry, last updated November 2023). Registry checked September 2026.
NPI: 1215949524
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
National Comparison by Procedure
Hip 13 vs 36 national avg 0.4x
avg
Knee 33 vs 45 national avg 0.7x
avg

Compared with 4,542 hip surgeons and 6,612 knee surgeons in the 2024 Medicare dataset.

Dr. Longjohn performs more knee replacement procedures than 53% of orthopedic surgeons in California, based on 2024 Medicare claims volume.Derived from the state ranking shown on this page: #229 of 491 ranked knee surgeons in California.

About Dr. Longjohn

Practice. Dr. Donald Longjohn is a board-certified orthopedic surgeon practicing in Los Angeles, California. The latest annual CMS data records 33 knee replacements and 13 hip replacements, 46 procedures in all. That is #229 in California for knee replacement. A Medicare provider since 2006.

Trend. Medicare records run from 2013 to 2024, 12 years. Volume has held between 38 and 64 procedures a year.

National context. Among 6,612 knee replacement surgeons tracked nationally, 33 procedures is below the national average of 45. Medicare covers part of all joint replacements, so true volume is likely higher.

Local context. Los Angeles has 34 orthopedic surgeons in the current Medicare data. Comparing volume and procedure mix across them is one way to narrow a shortlist.

Verified Medicare Cases

Knee Replacement
33 verified cases
#229 in California
Hip Replacement
13 verified cases
#303 in California
Estimated 2024 total: 160 – 200 procedures (all insurers)
Medicare fee-for-service share of national volume in 2024: 23% to 28% for knee replacement, 25% to 33% for hip replacement
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, 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. Longjohn Compares

Procedure volume compared to the California state average.

Hip Below Avg
13 Avg: 41
Knee Below Avg
33 Avg: 47
Dr. Longjohn California Average

Volume Trend Analysis

Dr. Longjohn's procedure volume has been consistent across 12 years of Medicare data, ranging from 38 to 64 procedures per year. This stability suggests a well-established joint replacement practice.

Years of Data 12
2024 Volume 46
Peak Volume 64 (2015)
Trend Stable

Hospital Affiliations & Quality

H
Keck Hospital Of Usc
4/5
Los Angeles, CA
Similar to national avg
H
Lac/Rancho Los Amigos National Rehabilitation Ctr
3/5
Downey, CA
Low case volume
H
Glendale Adventist Medical Center
4/5
Glendale, CA
Similar to national avg
H
Usc Kenneth Norris Jr Cancer Hospital
Los Angeles, CA
H
Lac/Olive View-Ucla Medical Center
2/5
Sylmar, 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.

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. Longjohn

How does Dr. Longjohn's procedure volume compare to other California surgeons?

Dr. Longjohn has performed 46 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. Longjohn ranks #295 out of 613 orthopedic surgeons in California.

What types of joint replacement does Dr. Longjohn perform?

Dr. Longjohn's Medicare data shows procedures in knee replacement (33 cases) and hip replacement (13 cases).

Are there other orthopedic surgeons near Dr. Longjohn in Los Angeles?

Yes. There are 34 orthopedic surgeons in Los Angeles 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. Longjohn 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, 25% to 33% for hip replacement, which puts Dr. Longjohn's total volume across all insurers at roughly 160 to 200 procedures against the 46 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. Longjohn's procedure volume changed over time?

Dr. Longjohn's procedure volume has been relatively stable over 12 years of Medicare data, ranging from 38 to 64 procedures per year between 2013 and 2024. Consistent volume over multiple years reflects a steady joint replacement practice.

Does Dr. Longjohn perform more than one type of joint replacement?

Yes. Dr. Longjohn's Medicare data shows procedures in knee replacement (33 cases), hip replacement (13 cases). Surgeons who perform multiple joint replacement types maintain broad technical skills across different anatomical joints.

Which hospitals is Dr. Longjohn affiliated with?

According to CMS facility affiliation data, Dr. Longjohn is affiliated with Keck Hospital Of Usc, Lac/Rancho Los Amigos National Rehabilitation Ctr, Glendale Adventist Medical Center, Usc Kenneth Norris Jr Cancer Hospital, Lac/Olive View-Ucla Medical Center.

How does Dr. Longjohn compare to other orthopedic surgeons in Los Angeles?

Among the 34 orthopedic surgeons in Los Angeles, Dr. Longjohn ranks #13 by total Medicare procedure volume. The highest-volume surgeon in Los Angeles has 211 verified Medicare procedures.

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

Keck Hospital Of Usc (4 out of 5 CMS stars, hip/knee complication rate similar to national average); Lac/Rancho Los Amigos National Rehabilitation Ctr (3 out of 5 CMS stars, insufficient case volume for complication rate comparison); Glendale Adventist Medical Center (4 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 Los Angeles, California

Dr. Longjohn's 46 Medicare procedures are below the Los Angeles average of 111. The table below compares verified procedure volumes for orthopedic surgeons practicing in Los Angeles.

SurgeonProceduresSpecialties
Dr. John Tiberi 211 Hip, Knee
Dr. Daniel Oakes 192 Hip, Knee
Dr. Micah Adamson 98 Hip, Knee
Dr. Vishal Hegde 97 Hip, Knee
Dr. Andrew Spitzer 71 Hip, Knee
Dr. Adam Sassoon 62 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.

Cite This Data

APA: OrthoProcedures. (2026). Dr. Donald Longjohn, M.D. -- Orthopedic Surgeon Profile. Retrieved from https://orthoprocedures.com/surgeons/ca/dr-donald-longjohn-los-angeles.html

Link: https://orthoprocedures.com/surgeons/ca/dr-donald-longjohn-los-angeles.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.