#29 Hip
#70 Knee

Dr. Aaron Johnson, MD

Orthopedic Surgery
79 procedures 3 hospitals Baltimore, MD
Latest available Medicare data — updated April 2026
Rising Star
Hip replacement recovery kit Essentials every patient wishes they bought first
National Comparison by Procedure
Hip 45 vs 36 avg (4,526 surgeons)
Knee 34 vs 45 avg (6,720 surgeons)

Dr. Aaron Johnson is a board-certified orthopedic surgeon practicing in Baltimore, Maryland. A Medicare provider since 2012, Dr. Johnson has performed 45 Medicare-verified hip replacements (#29 in Maryland) and 34 knee replacements, for a combined total of 79 procedures.

In Maryland, Dr. Johnson performs near average in hip (45 vs 40 avg), below average in knee (34 vs 50 avg).

Dr. Johnson's reported Medicare volume is split between hip replacements (45 cases) and knee replacements (34 cases).

Beyond general orthopedic surgery, Dr. Johnson holds additional credentials in Orthopaedic Trauma, reflecting subspecialty training that may benefit patients with complex joint conditions.

Baltimore is home to 38 orthopedic surgeons in the current Medicare dataset. Patients in the Baltimore area can compare surgeon volume and procedure specialization to find the right fit for their joint replacement needs.

Medicare records for Dr. Johnson extend back to 2020, covering 4 years of data. Over that period, recorded procedure volume increased from 12 to 79 in the most recent data, a 558% increase. This sustained growth reflects an expanding joint replacement practice.

Among 4,526 hip replacement surgeons tracked nationally, Dr. Johnson's 45 verified procedures is above the national average of 36.

Verified Medicare Cases

Hip Replacement
45 verified cases
#29 in Maryland
Knee Replacement
34 verified cases
#70 in Maryland
Estimated total: 210 – 240 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. Johnson Compares

Procedure volume compared to the Maryland state average.

Hip Average
45 Avg: 40
Knee Below Avg
34 Avg: 50
Dr. Johnson Maryland Average

Contact & Location

Phone: 410-448-6400
22 S Greene St
Baltimore, MD 21201
NPI: 1538420641
Credentials: MD
Active Medicare provider (NPI verified)
14 years of practice experience
Licensed MD
Licensed surgical specialist
Board-certified orthopedic surgeon
Contact information available
Find Practice on Google Maps

Volume Trend Analysis

Dr. Johnson's Medicare-recorded procedure volume has trended upward over 4 years, increasing 558% from 12 procedures in 2020 to 79 in the most recent data.

Years of Data 4
2023 Volume 79
Peak Volume 79 (2023)
Trend Growing

Hospital Affiliations & Quality

H
University Of Maryland Medical Center
★★☆☆☆
Baltimore, MD
Low case volume
H
Umd Baltimore Washington Medical Center
★★★★☆
Glen Burnie, MD
Similar to national avg
H
University Of Md Capital Region Medical Center
★★★☆☆
Upper Marlboro, MD
Low case volume

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.

Hip Replacement Recovery Overview

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

Week 1-2 Walking with assistive device (walker or cane). Gentle range-of-motion exercises begin. Most patients can manage basic self-care.
Week 3-6 Transition to walking independently. Resume driving short distances. Physical therapy focuses on strength and balance.
Week 7-12 Return to most daily activities and light exercise. Stair climbing improves. Many patients return to desk work.
Month 4-6 Full recovery for most patients. Resume recreational activities, golf, swimming, and low-impact exercise.

Individual recovery varies based on overall health, age, and adherence to physical therapy. View full hip replacement recovery guide and product recommendations

Frequently Asked Questions About Dr. Johnson

How does Dr. Johnson's procedure volume compare to other Maryland surgeons?

Dr. Johnson has performed 79 Medicare-verified joint replacement procedures. This is in line with the Maryland average of 72 procedures per surgeon. Dr. Johnson ranks #50 out of 161 orthopedic surgeons in Maryland.

What types of joint replacement does Dr. Johnson perform?

Dr. Johnson's Medicare data shows procedures in hip replacement (45 cases) and knee replacement (34 cases).

Are there other orthopedic surgeons near Dr. Johnson in Baltimore?

Yes. There are 38 orthopedic surgeons in Baltimore 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 Maryland surgeons.

What does the Medicare data for Dr. Johnson 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. Johnson's total practice volume — including private insurance and Medicare Advantage patients — is likely higher than the 79 procedures shown here.

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

Yes. Dr. Johnson's Medicare-recorded volume has increased from 12 procedures in 2020 to 79 in the most recent data, a 558% increase over 4 years. This upward trend suggests an expanding joint replacement practice. Peak volume was 79 procedures in 2023.

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

Yes. Dr. Johnson's Medicare data shows procedures in hip replacement (45 cases), knee replacement (34 cases). Surgeons who perform multiple joint replacement types maintain broad technical skills across different anatomical joints.

Which hospitals is Dr. Johnson affiliated with?

According to CMS facility affiliation data, Dr. Johnson is affiliated with University Of Maryland Medical Center, Umd Baltimore Washington Medical Center, University Of Md Capital Region Medical Center.

How does Dr. Johnson compare to other orthopedic surgeons in Baltimore?

Among the 38 orthopedic surgeons in Baltimore, Dr. Johnson ranks #15 by total Medicare procedure volume. The highest-volume surgeon in Baltimore has 304 verified Medicare procedures.

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

University Of Maryland Medical Center (2 out of 5 CMS stars, insufficient case volume for complication rate comparison); Umd Baltimore Washington Medical Center (4 out of 5 CMS stars, hip/knee complication rate similar to national average); University Of Md Capital Region Medical Center (3 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 Baltimore, Maryland

Dr. Johnson's 79 Medicare procedures are below the Baltimore average of 176. The table below compares verified procedure volumes for orthopedic surgeons practicing in Baltimore.

SurgeonProceduresSpecialties
Dr. Joseph Ciotola 304 Hip, Knee, Shoulder
Dr. Marc Hungerford 209 Hip, Knee
Dr. Frank Ebert 185 Hip, Knee
Dr. Robert McKinstry 158 Hip, Knee
Dr. Henry Boucher 150 Hip, Knee
Dr. Harpal Khanuja 147 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. Aaron Johnson, MD -- Orthopedic Surgeon Profile. Retrieved from https://orthoprocedures.com/surgeons/md/dr-aaron-johnson-baltimore.html

Link: https://orthoprocedures.com/surgeons/md/dr-aaron-johnson-baltimore.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.