A massive tear of the rotator cuff is a debilitating condition that causes pain, significant impairments in strength, and resultant loss of activity of the affected arm. To our knowledge, there is no Level 1 evidence comparing surgical procedures to treat massive rotator cuff tears. Adding the first randomized controlled trial to will be a substantial contribution to the current body of evidence available in the subject of massive rotator cuff tears. Most studies found in the literature following patients with massive rotator cuff tears are retrospective, have small numbers of patients, offer no control group and do not adequately compare treatment methods.Moreover, there is no consensus from experts regarding which treatment is superior.

Our multicentre orthopaedic study group proposes a multicentre randomized clinical trial prospectively comparing latissimus dorsi tendon transfer to arthroscopic management for the treatment of massive rotator cuff tears. This study will include the use of comprehensive functional, motor and radiographic outcome assessments.

Inclusion Criteria:

• Men or women aged 40 to 65 years of age
• Massive rotator cuff tear, identified by MRI as being greater than 4cm in greatest diameter.
• Provision of informed consent

Exclusion Criteria:

• Absence of functioning latissimus dorsi muscle (assessed by "cough test"
• Absence of subscapularis muscle insertion (assessed by MRI)
• Glenohumeral arthritis of Grade 2 or higher, including evidence of acromio-humeral arthritis
• Acute tears (identifiable injury which precluded symptoms in past 6 months)
• Neurologic injury causing paralysis of affected shoulder girdle/arm
• Limited life expectancy due to significant medical co-morbidity or medical contraindication to surgery (ASA Grade IV or higher)
• Anticipated problems, in the judgement of the investigators, with maintaining follow-up (i.e. patients with no fixed address, patients not mentally competent to give consent, etc.)