low recruitment rate and high rate of loss-to-followup

The purpose of this study is to determine whether injection of platelet-rich plasma derived from patient's blood is effective in treatment of shoulder subacromial impingement syndrome as compared to the current protocol of methylprednisolone injection.

Patients presenting with shoulder pain to the study location will be screened by the principal investigator. Once diagnosed clinically with shoulder subacromial impingement syndrome, they will be invited to join the study. They will be invited to separate academic office to be explained about the study, its voluntary and confidential basis as per our Institutional Review Board (IRB) approved protocols.

After signing informed consent form and recruitment, they will be assigned randomly to one of the study arms through software-generated sequential allocation packaged in an opaque envelope. All involved except the principal investigator and patient are blinded.

There are two groups/arms in the study. The experimental arm will include subacromial injection of study subjects with autologous platelet-rich plasma; wheres subjects in the other study arm will be injected with methylprednisolone.

The outcome will be assessed through three scores. The study subjects will be asked to complete Oxford Shoulder Score questionnaire and health-related quality of life SF-36 questionnaire and Constant-Murley score will be measured through physician-based assessment done by the residents involved in the study. This will be done during the baseline visit before injection and repeated at 2, 6, 12 weeks and 6 months follow-up visits.

Also any adverse effects of both treatment arms will be monitored and reported as appropriate.

The investigators hypothesize that injecting platelet-rich plasma into the subacromial space of patients with subacromial impingement will result in decreased pain and increased function at 6 months follow-up (assessed by Constant-Murley Score, Oxford Shoulder Score, and Short Form-36 (SF-36) questionnaire) as compared to patients injected with methylprednisolone.

Inclusion Criteria:

• Any adult male or female between 18 and 65 years of age, inclusive, with clinical diagnosis of shoulder subacromial impingement

Exclusion Criteria:

• Age below 18 or above 65 years
• History of prior shoulder injections or surgery
• History of fracture of the acromion, clavicle, scapula, or proximal humerus
• Known allergy to corticosteroids
• Known allergy to lidocaine