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Validation of the Western Ontario Rotator Cuff Index in Patients With Arthroscopic Rotator Cuff Repair (WORC)

This study has been completed.
Information provided by (Responsible Party):
Ronald Wessel, St. Antonius Hospital Identifier:
First received: February 9, 2012
Last updated: April 30, 2014
Last verified: April 2014

Arthroscopic rotator cuff repair is described as being a successful procedure. These results are often derived from clinical general shoulder examinations, which are then classified as 'excellent', 'good', 'fair' or 'poor'. However, the cut-off points for these classifications vary and sometimes modified scores are used.

Arthroscopic rotator cuff repair is performed to improve quality of life. Therefore, disease specific health-related quality of life patient-administered questionnaires are needed. The WORC is a quality of life questionnaire designed for patients with disorders of the rotator cuff. The score is validated for rotator cuff disease, but not for rotator cuff repair specifically.

The aim of this study is to investigate reliability, validity and responsiveness of WORC in patients undergoing arthroscopic rotator cuff repair.

Rotator Cuff Lesion
Disorder of Rotator Cuff
Other Instability, Shoulder

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: Validation of the Western Ontario Rotator Cuff Index in Patients With Arthroscopic Rotator Cuff Repair

Further study details as provided by St. Antonius Hospital:

Primary Outcome Measures:
  • Reliability of the WORC [ Time Frame: 6 months ]
    Reliability of the WORC is tested by comparing the results at T0 with T1. T1 is planned 2-3 weeks after T0, because we expect that the symptoms do not change between these two moments and the time span is large enough to forget initial responses to the questions. In order to signal change in severity of the symptoms, at both moments patients are asked to rate their shoulder hindrance. To determine test-retest reliability, intraclass correlation coefficients (ICC) are used.

Secondary Outcome Measures:
  • Criterion validity of the WORC [ Time Frame: 6 months ]
    Criterion validity is measured by comparing WORC with a general quality of life questionnaire (SF-36) and a commonly used clinical shoulder score (Constant Score) both at T0 and T1. Bland Altman plots will be used to estimate 95% boundaries of concurrence.

  • Responsiveness of the WORC [ Time Frame: 6 months ]
    Responsiveness will be determined by calculating the standardized response means and effect sizes on T0 and T2 scores on WORC, SF-36 and Constant scores for the subgroups.

  • Differentiation between patient groups [ Time Frame: 6 months ]
    A comparison of WORC scores between the three distinct groups is made, to see whether WORC scores can differentiate between them. WORC scores will be compared with SF-36 to investigate whether the noted differences correlate with notable clinical differences and can be expressed as MCID's (minimal clinical important differences).

Enrollment: 118
Study Start Date: November 2011
Study Completion Date: March 2014
Primary Completion Date: December 2013 (Final data collection date for primary outcome measure)
Rotator cuff repair group
Patients undergoing an arthroscopic rotator cuff repair
DRC without rupture
Disorders of the rotator cuff without rupture
Shoulder instability
Shoulder instability

Detailed Description:

An approved translation of the WORC into Dutch is used. In this prospective study three groups of patients are used: 1.Arthroscopic rotator cuff repair; 2.Disorders of the rotator cuff without rupture; 3.Shoulder instability.

The WORC, SF-36 and the Constant Score are obtained twice before therapy is started to measure reliability and validity. Responsiveness is tested by obtaining the same tests after therapy.


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
  1. Patients undergoing arthroscopic rotator cuff repair. These patients have a clinical suspicion of a symptomatic rotator cuff tear and a partial or full thickness lesion seen on MRI or Ultrasound and confirmed during the arthroscopic repair procedure.
  2. Patients diagnosed as having non-Ruptured DRC. They have a clinical suspicion of DRC and no rupture of the rotator cuff on MRI or Ultrasound.
  3. Patients will be diagnosed with shoulder instability

Inclusion Criteria:

  • 18 years or older
  • written informed consent
  • diagnosis for group 1, 2 or 3

Exclusion Criteria:

  • lack of understanding the Dutch language
  • not able to complete questionnaires independently
  • additional shoulder pathology like adhesive capsulitis, AC-pathology and osteoarthritis
  • previous shoulder surgery
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01532492

Department of Orthopedics, St. Antonius Hospital
Nieuwegein, Netherlands, 3430 EM
Sponsors and Collaborators
St. Antonius Hospital
Principal Investigator: Ronald N Wessel, MD St. Antonius Hospital
Principal Investigator: Henk van Mameren, PhD, MD Department of Epidemiology, Caphri research school, Maastricht University
Principal Investigator: Rob A de Bie, PhD, MA, RPt Department of Epidemiology, Caphri research school, Maastricht University
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Ronald Wessel, Principal investigator, St. Antonius Hospital Identifier: NCT01532492     History of Changes
Other Study ID Numbers: LTME/Z-11.19/WORC
Study First Received: February 9, 2012
Last Updated: April 30, 2014

Keywords provided by St. Antonius Hospital:
Rotator cuff
Responsiveness processed this record on May 25, 2017