#38 Shoulder
#237 Knee

Dr. Donald Weimer, M.D.

Orthopedic Surgery
35 procedures 2 hospitals O Fallon, IL
Latest available Medicare data — updated April 2026
Shoulder replacement recovery kit Slings, cold therapy, and adaptive clothing for recovery
National Comparison by Procedure
Knee 14 vs 45 avg (6,720 surgeons)
Shoulder 21 vs 28 avg (2,092 surgeons)

Dr. Donald Weimer is a board-certified orthopedic surgeon practicing in O Fallon, Illinois. A Medicare provider since 2006, Dr. Weimer has performed 21 Medicare-verified shoulder replacements (#38 in Illinois) and 14 knee replacements, for a combined total of 35 procedures.

In Illinois, Dr. Weimer performs below average in shoulder (21 vs 28 avg), below average in knee (14 vs 51 avg).

Dr. Weimer's reported Medicare volume is split between shoulder replacements (21 cases) and knee replacements (14 cases).

O Fallon is home to 2 orthopedic surgeons in the current Medicare dataset. Patients in the O Fallon area can compare surgeon volume and procedure specialization to find the right fit for their joint replacement needs.

Dr. Weimer's Medicare record spans 11 years from 2013 through 2023. Procedure volume has remained consistent during that period, ranging from 12 to 45 procedures per year, reflecting a steady joint replacement practice.

Dr. Weimer's 21 shoulder replacement procedures is below the national average of 28 among 2,092 surgeons. Medicare data captures roughly a third of all joint replacements, so actual volume is likely higher.

Verified Medicare Cases

Shoulder Replacement
21 verified cases
#38 in Illinois
Knee Replacement
14 verified cases
#237 in Illinois
Estimated total: 90 – 110 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. Weimer Compares

Procedure volume compared to the Illinois state average.

Knee Below Avg
14 Avg: 51
Shoulder Below Avg
21 Avg: 28
Dr. Weimer Illinois Average

Contact & Location

Phone: 618-641-5800
1512 N Green Mount Rd
O Fallon, IL 62269
NPI: 1932152980
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. Weimer's procedure volume has been consistent across 11 years of Medicare data, ranging from 12 to 45 procedures per year. This stability suggests a well-established joint replacement practice.

Years of Data 11
2023 Volume 35
Peak Volume 45 (2021)
Trend Stable

Hospital Affiliations & Quality

H
Hshs St Elizabeth'S Hospital
★★★★☆
O Fallon, IL
Similar to national avg
H
St Josephs Hospital
★★★★☆
Breese, IL
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.

Shoulder Replacement Recovery Overview

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

Week 1-3 Arm in a sling for protection. Gentle pendulum exercises under therapist guidance. Focus on pain management and wound care.
Week 4-6 Gradual sling weaning. Begin passive and active-assisted range-of-motion exercises. Light daily activities resume.
Week 7-12 Active range-of-motion exercises. Light strengthening begins. Most patients can drive and perform desk work.
Month 4-6 Progressive strengthening continues. Return to most activities. Full recovery may take 6-12 months for complete shoulder strength.

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

Frequently Asked Questions About Dr. Weimer

How does Dr. Weimer's procedure volume compare to other Illinois surgeons?

Dr. Weimer has performed 35 Medicare-verified joint replacement procedures. The Illinois average is 69 procedures per surgeon. Medicare data captures roughly one-third of all joint replacements, so total volume may be higher. Dr. Weimer ranks #196 out of 323 orthopedic surgeons in Illinois.

What types of joint replacement does Dr. Weimer perform?

Dr. Weimer's Medicare data shows procedures in shoulder replacement (21 cases) and knee replacement (14 cases).

Are there other orthopedic surgeons near Dr. Weimer in O Fallon?

Yes. There are 2 orthopedic surgeons in O Fallon 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 Illinois surgeons.

What does the Medicare data for Dr. Weimer 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. Weimer's total practice volume — including private insurance and Medicare Advantage patients — is likely higher than the 35 procedures shown here.

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

Dr. Weimer's procedure volume has been relatively stable over 11 years of Medicare data, ranging from 12 to 45 procedures per year between 2013 and 2023. Consistent volume over multiple years reflects a steady joint replacement practice.

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

Yes. Dr. Weimer's Medicare data shows procedures in shoulder replacement (21 cases), knee replacement (14 cases). Surgeons who perform multiple joint replacement types maintain broad technical skills across different anatomical joints.

Which hospitals is Dr. Weimer affiliated with?

According to CMS facility affiliation data, Dr. Weimer is affiliated with Hshs St Elizabeth'S Hospital, St Josephs Hospital.

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

Hshs St Elizabeth'S Hospital (4 out of 5 CMS stars, hip/knee complication rate similar to national average); St Josephs Hospital (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 O Fallon, Illinois

Dr. Weimer's 35 Medicare procedures are below the O Fallon average of 58. The table below compares verified procedure volumes for orthopedic surgeons practicing in O Fallon.

SurgeonProceduresSpecialties
Dr. Kevin McCarthy 81 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. Donald Weimer, M.D. -- Orthopedic Surgeon Profile. Retrieved from https://orthoprocedures.com/surgeons/il/dr-donald-weimer-o-fallon.html

Link: https://orthoprocedures.com/surgeons/il/dr-donald-weimer-o-fallon.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.