Electromyography Evaluation of Subscapularis Function After Total Shoulder Arthroplasty

November 1, 2023 updated by: April Armstrong, Milton S. Hershey Medical Center

Electromyography Evaluation of Subscapularis Function After Total Shoulder

The primary objective is to document function of the structurally intact subscapularis after total shoulder arthroplasty by using electromyography. Structural integrity of the subscapularis will be confirmed using ultrasound.

The secondary objective is to determine the diagnostic accuracy of the belly compression and lift off tests in evaluating the integrity and function of the subscapularis when compared to the ultrasound and electromyography (EMG).

This will be accomplished by enrolling and evaluating patients with a primary diagnosis of osteoarthritis who have had a total shoulder replacement preformed by the PI from September 2003 through December 2007.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

The functional status of the subscapularis following total shoulder arthroplasty has not been well documented. There is evidence of loss of subscapularis function shown through physical exam in up to 2/3 of patients following total shoulder arthroplasty. [1] Multiple techniques for subscapularis repair have been demonstrated with varying degrees of post operative function, ranging from 11-66% abnormal function on physical exam. [1-3] The belly compression test and the lift off test, which are the main physical exam tests used for evaluation following surgery, are of questionable reliability as indicators of the functionality of the subscapularis. [4,5] Through comparing ultrasound evidence of an intact subscapularis to physical exam findings it has been recognized that the belly compression test has low sensitivity and specificity for subscapularis integrity. [5] Internal rotation is often limited in many postoperative total shoulder patients, which could lead to false positive results. This questions the validity of the outcomes of the studies in which the standard of testing function was through exam.

Ultrasound is a reliable exam for illustration of structural damage to the subscapularis tendon but additional testing is needed to evaluate the function of the structurally intact subscapularis. [5,6] Irreparable changes in the muscle function or nerve denervation could also result in false positive belly compression and lift off tests. The ability to accurately determine the functionality of the subscapularis following total shoulder replacement is imperative to clinic management. Although studies have shown functional abnormalities through physical exam, none have documented the functional status of the subscapularis using objective means such as EMG.

Study Type

Observational

Enrollment (Actual)

32

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Pennsylvania
      • Hershey, Pennsylvania, United States, 17033
        • Penn State College of Medicine, Penn State Milton S. Herhsey Medical Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

45 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

The subject population for this study consists of adult patients with a primary diagnosis of osteoarthritis who have had a total shoulder arthroplasty preformed by the PI between September 2003 through December 2007.

Description

Inclusion Criteria:

  • age >45yrs;
  • primary diagnosis of osteoarthritis of the shoulder
  • total shoulder replacement performed by Dr. Armstrong between September 2003 through December 2007.

Exclusion Criteria:

  • Known contraindications to ultrasound and/or EMG
  • Inability to provide informed consent
  • History of recent trauma to the shoulder
  • Typical shoulder pain
  • Other suspected shoulder pathology (i.e. tumor, infection)
  • Pregnancy
  • Bilateral total shoulder arthroplasty

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
s/p Total Shoulder Arthroplasty
The subject population for this study consists of adult patients with a primary diagnosis of osteoarthritis who have had a total shoulder arthroplasty preformed by the PI between September 2003 through December 2007.
Other: Evaluation
For this research study each enrolled subject will have a clinical exam, including range of motion (ROM), and strength testing. The lift off and belly compression tests will be performed. An ultrasound of the shoulder will be done to determine the integrity of the subscapularis tendon. An EMG will be done to determine functionality of the subscapularis.
Other Names:
  • Ultrasound
  • EMG
  • ROM
  • Clinic Evaluation

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
The primary goal of this study is to document the function of the subscapularis after total shoulder arthroplasty
Time Frame: end of enrollment
end of enrollment

Secondary Outcome Measures

Outcome Measure
Time Frame
The sensitivity and specificity of the belly compression and lift off test will be compared to the results of the ultrasound and electromyography (EMG)
Time Frame: end of enrollment
end of enrollment

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Milton S. Hershey Medical Center

Investigators

  • Principal Investigator: April Armstrong, MD, Penn State College of Medicine, Penn State Milton S. Hershey Medical Center

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

August 1, 2008

Primary Completion (Actual)

June 1, 2013

Study Completion (Actual)

June 1, 2013

Study Registration Dates

First Submitted

October 22, 2008

First Submitted That Met QC Criteria

October 22, 2008

First Posted (Estimated)

October 24, 2008

Study Record Updates

Last Update Posted (Actual)

November 3, 2023

Last Update Submitted That Met QC Criteria

November 1, 2023

Last Verified

November 1, 2023

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • IRB#27370

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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