The aim of this study is to evaluate the efficacy of ultrasound-guided injection of platelet-derived lyophilized growth factors in treatment of subacromial impingement.

A new patented product named lyophilized Growth Factors has been developed. It is a novel advanced and refined form of conventional platelet-rich plasma. Effectiveness of intra-articular lyophilized Growth Factors injection has been studied in thirty patients with symptomatic primary knee osteoarthritis and has shown encouraging results regarding improvement of pain, stiffness and function in addition to decreasing knee effusion.

The lack of good quality evidence to support the efficacy of injecting platelet-derived lyophilized growth factors in treatment of subacromial impingement highlights the need for thorough evaluation of the outcome of this novel therapeutic option in patients with 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.