Electromyography Evaluation of Subscapularis Function After Total Shoulder Arthroplasty

This study is enrolling participants by invitation only.
Sponsor:
Information provided by (Responsible Party):
April Armstrong, Penn State University
ClinicalTrials.gov Identifier:
NCT00779974
First received: October 22, 2008
Last updated: May 23, 2012
Last verified: May 2012

October 22, 2008
May 23, 2012
August 2008
January 2013   (final data collection date for primary outcome measure)
The primary goal of this study is to document the function of the subscapularis after total shoulder arthroplasty [ Time Frame: end of enrollment ] [ Designated as safety issue: No ]
Same as current
Complete list of historical versions of study NCT00779974 on ClinicalTrials.gov Archive Site
The sensitivity and specifity of the belly compression and lift off test will be compared to the results of the ultrasound and EMG [ Time Frame: end of enrollment ] [ Designated as safety issue: No ]
Same as current
Not Provided
Not Provided
 
Electromyography Evaluation of Subscapularis Function After Total Shoulder Arthroplasty
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 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.

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.

Observational
Observational Model: Case-Only
Time Perspective: Prospective
Not Provided
Not Provided
Non-Probability Sample

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.

Osteoarthritis
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
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.
Intervention: Other: Evaluation

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Enrolling by invitation
40
May 2013
January 2013   (final data collection date for primary outcome measure)

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
Both
45 Years and older
No
Contact information is only displayed when the study is recruiting subjects
United States
 
NCT00779974
IRB#27370
No
April Armstrong, Penn State University
Penn State University
Not Provided
Principal Investigator: April Armstrong, MD Penn State College of Medicine, Penn State Milton S. Hershey Medical Center
Penn State University
May 2012

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP