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Electromyography Evaluation of Subscapularis Function After Total Shoulder Arthroplasty

This study has been completed.
Sponsor:
ClinicalTrials.gov Identifier:
NCT00779974
First Posted: October 24, 2008
Last Update Posted: February 27, 2015
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Information provided by (Responsible Party):
April Armstrong, Milton S. Hershey Medical Center
  Purpose

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.


Condition Intervention
Osteoarthritis Other: Evaluation

Study Type: Observational
Study Design: Observational Model: Case-Only
Time Perspective: Prospective
Official Title: Electromyography Evaluation of Subscapularis Function After Total Shoulder

Resource links provided by NLM:


Further study details as provided by April Armstrong, Milton S. Hershey Medical Center:

Primary Outcome Measures:
  • The primary goal of this study is to document the function of the subscapularis after total shoulder arthroplasty [ Time Frame: end of enrollment ]

Secondary Outcome Measures:
  • 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 ]

Enrollment: 32
Study Start Date: August 2008
Study Completion Date: June 2013
Primary Completion Date: June 2013 (Final data collection date for primary outcome measure)
Groups/Cohorts Assigned Interventions
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:
  • ROM
  • Ultrasound
  • EMG
  • Clinic Evaluation

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.

  Eligibility

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Ages Eligible for Study:   45 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
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.
Criteria

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
  Contacts and Locations
Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00779974


Locations
United States, Pennsylvania
Penn State College of Medicine, Penn State Milton S. Herhsey Medical Center
Hershey, Pennsylvania, United States, 17033
Sponsors and Collaborators
Milton S. Hershey Medical Center
Investigators
Principal Investigator: April Armstrong, MD Penn State College of Medicine, Penn State Milton S. Hershey Medical Center
  More Information

Publications:
Responsible Party: April Armstrong, Associate Professor, Milton S. Hershey Medical Center
ClinicalTrials.gov Identifier: NCT00779974     History of Changes
Other Study ID Numbers: IRB#27370
First Submitted: October 22, 2008
First Posted: October 24, 2008
Last Update Posted: February 27, 2015
Last Verified: February 2015

Keywords provided by April Armstrong, Milton S. Hershey Medical Center:
Total Shoulder Arthroplasty
Osteoarthritis

Additional relevant MeSH terms:
Osteoarthritis
Arthritis
Joint Diseases
Musculoskeletal Diseases
Rheumatic Diseases