The Efficacy of Local Anesthetics to Reduce Shoulder Pain Post-Steroid Injections

The specific aim of this prospective study is to determine whether local anesthetics prior to subacromial steroid injections reduce pain and consequently if they are cost-effective in the treatment for shoulder pathology.

Shoulder pain is a common problem that can be estimated to be prevalent in up to 15 percent of the patient population registered to general practices and is second only to back pain in patients seeking treatment for musculoskeletal issues in the primary care setting. As a common source of distress, shoulder pain contributes significantly to health care costs. Rotator cuff disease due to impingement, tendonitis or bursitis is a frequent cause of shoulder pain and dysfunction. Initial treatment consists of a conservative approach of activity modification, oral nonsteroidal anti-inflammatory drugs (NSAIDs) and supervised physical therapy. However, if the patients' symptoms persist, subacromial injections of a local anesthetic such as lidocaine, and a corticosteroid may be indicated as a sequential treatment option. The steroid injection itself can be a painful process, so administering a local anesthetic prior to the steroid injection is thought to mitigate pain or reduce possible discomfort during and immediately following the procedure. Though there is evidence advocating for the benefits of combining local anesthetics and corticosteroids for the treatment of subacromial pathologies, it is not conclusive whether local anesthesia significantly enhances the pain relieving effect of steroids. Should local anesthesia not have a significant impact on the patient's pain intensity, then the use of corticosteroids alone could potentially result in reduced costs in care.

Injection of 1 ml of 40 mg Kenalog combined with 4 ml of 1% lidocaine after 2 ml or 1% lidocaine by subcutaneous injection

Injection of 1 ml of 40 mg Kenalog combined with 4 ml of 1% lidocaine after applying ethyl chloride spray for 3 seconds

Pain assessed on a visual analog scale from 1 (no pain) to 10 (worst pain imaginable). Pain score at 10 minutes post-injection is subtracted from baseline pre-injection score. Positive numbers to represent increases and negative numbers to represent decreases.

Inclusion Criteria: Ages 18 to 70 years old Shoulder pain lasting at least 4 weeks Inability to use arm with restriction of movement and loss of full function. Able to understand study and provide voluntary, written informed consent Exclusion Criteria: Less than 18 or greater than 70 years old Contraindications of previous injections and previous shoulder surgery Unable to understand consent form (in the opinion of the PI) Non-English speaking individuals Medication contradictions to lidocaine, corticosteroids