Effectiveness of Lyophilized Growth Factors for Subacromial Impingement

Inclusion Criteria: * Clinically: 1. Anterolateral shoulder and/or lateral upper arm pain. 2. Painful arc of motion between 70° and 120°. 3. Positive impingement sign (Neer's test or Hawkins-Kennedy test). * Ultrasonographically: The elicitation of a transient arc of pain during shoulder abduction which coincides with passage of the supraspinatus insertion beneath the coraco-acromial arch. Exclusion Criteria: * History of shoulder surgery, fracture, dislocation or subluxation. * Patients with full-thickness rotator cuff tear, weakness on arm elevation, or positive "drop arm sign". * Patients who have been diagnosed with a frozen shoulder or degenerative arthropathy of the glenohumeral joint. * Patients with disorders of the cervical spine or upper extremity that have a significant impact on the shoulder * Patients with diabetes mellitus, rheumatoid arthritis, hypothyroidism or other painful or function limiting disorders of the shoulder. * Significant cardiovascular, renal or hepatic disease. * Active infection in the area to be treated.