Superior Glenohumeral Translation in Patients With Degenerative Rotator Cuff Tears
Condition: Rotator Cuff Tear or Rupture, Not Specified as Traumatic
MeSH terms: Rupture; Rotator Cuff Injuries
Study type: Observational

Summary: 
      Degenerative partial and complete rupture of the rotator cuff is a common injury among elder
      patients. However, the clinical manifestation varies largely with some patients having severe
      pain and limiting range of motion and others having no complaints. The basic functions of the
      rotator cuff are to facilitate shoulder motion and stabilization and centering of the
      glenohumeral joint. The objective of this study is to quantify the difference in superior
      glenohumeral translation in patients with degenerative rotator cuff tear compared to healthy
      control subjects and to determine the effect of isolated complete supraspinatus tear and
      combined complete supraspinatus and either partial infraspinatus or partial subscapularis
      tear.
    

Detailed description: 
      The study will examine a cohort of 10 patients with isolated complete supraspinatus muscle
      tear and 10 patients with complete supraspinatus muscle tear and either partial infraspinatus
      muscle tear or partial subscapularis muscle tear, and a cohort of 10 age-matched healthy
      control persons. The participants will be recruited from the Clinic of Orthopaedics and
      Traumatology at the University Hospital Basel. Inclusion criteria: 45 years < age < 65 years;
      degenerative complete supraspinatus muscle tear or complete supraspinatus muscle tear and
      either partial infraspinatus muscle tear or partial subscapularis muscle tear; unilateral
      rotator cuff tear. Exclusion criteria: traumatic tendon ruptures; prior treatment of the
      ipsilateral upper extremity; clinical history of the contralateral glenohumeral joint; no
      complete supraspinatus muscle tear; tears in more than two rotator cuff muscles;
      neuromuscular disorders affecting upper limb movement; additional pathologies that influence
      the mobility of the shoulder joint; inability to provide informed consent.

      Patients will complete the health questionnaire and reflective markers and electromyographic
      sensors will be placed on anatomical landmarks and shoulder muscles, respectively, before
      loaded and unloaded abduction and flexion arm movements will be performed. Centre of rotation
      of both shoulders will be calculated to determine glenohumeral translation. This parameter
      will be compared between patient groups and control subjects using linear mixed models with
      group membership and load as fixed factor and subject as random factor. The critical shoulder
      angle will be included as covariate into the model to detect a potential modulating role of
      this factor on glenohumeral translation.
    

Intervention name(s): Glenohumeral translation assessment
Intervention type(s): Diagnostic Test
Intervention description(s): amount of glenohumeral translation under load
Observational model: Cohort
Time perspective: Retrospective
Sampling method: Non-Probability Sample
Study population: 
        -  10 patients with isolated complete supraspinatus muscle tear

          -  10 patients with complete supraspinatus muscle tear and either partial infraspinatus
             muscle tear or partial subscapularis muscle tear

          -  10 healthy control subjects