Standardized and Modified Corticosteroid Subacromial Injection for Shoulder Impingement Syndrome (SMCSINJ)

Comparative Effectiveness of the Standardized and Modified Ultrasound Guided Corticosteroid Subacromial Injection for Participants With Shoulder Impingement Syndrome

Subacromial injection is a useful procedure to counteract shoulder impingement syndrome. With the aid of high-resolution ultrasound, the needle can be introduced precisely into the subacromial/subdeltoid bursa located between the acromion above and the supraspinatus tendon below. The standardized method allows the injectate to distribute along the subdeltoid bursa, further reliving pain from subacromial/subdeltoid impingement. In a substantial part of shoulder pain patients, it is common to accompany pain along the bicipital groove, which the biceps long head tendon courses through. The biceps long head tendon is attached to the superior labrum of the glenoid cavity and acts as the second important structure to prevent upward migration of the humeral head, following the supraspinatus tendon. Overuse injury of the biceps tendon is a likely cause of anterior shoulder pain. Concomitant administration of medication into the subacromial bursa and biceps tendon sheath is theoretically more effective than injection to the subacromial bursa only because the formal procedure targets two vulnerable structures in shoulder impingement syndrome at once. Regarding the standard ultrasound-guided subacromial injection. Therefore, we will conduct a randomized controlled trial investigating the effectiveness of standard subacromial injection in comparison with a novel approach simultaneously injecting the subacromial bursa and biceps tendon sheath.

Introduction Subacromial injection is a useful procedure to counteract shoulder impingement syndrome. With the aid of high-resolution ultrasound, the needle can be introduced precisely into the subacromial/subdeltoid bursa located between the acromion above and the supraspinatus tendon below. The standardized method allows the injectate to distribute along the subdeltoid bursa, further reliving pain from subacromial/subdeltoid impingement. In a substantial part of shoulder pain patients, it is common to accompany pain along the bicipital groove, which the biceps long head tendon courses through. The biceps long head tendon is attached to the superior labrum of the glenoid cavity and acts as the second important structure to prevent upward migration of the humeral head, following the supraspinatus tendon. Overuse injury of the biceps tendon is a likely cause of anterior shoulder pain. Concomitant administration of medication into the subacromial bursa and biceps tendon sheath is theoretically more effective than injection to the subacromial bursa only because the formal procedure targets two vulnerable structures in shoulder impingement syndrome at once. Regarding the standard ultrasound-guided subacromial injection. Therefore, we will conduct a randomized controlled trial investigating the effectiveness of standard subacromial injection in comparison with a novel approach simultaneously injecting the subacromial bursa and biceps tendon sheath. Material and methods: Participants: adult patients (>20 year old) with shoulder impingement syndrome Inclusion criteria: shoulder pain>3 weeks; no contraindication for local injection; Visual analogue scale of pain>4 Participant number: at least 30 at each treatment arm Exclusion criteria: systemic rheumatologic disease, Ankylosing spondylitis, malignancy, major trauma or recent injections on the affected shoulder Study design: single center double blind randomized controlled trial Randomization method: block randomization (block size: 4), computerized random sequence generation, allocation concealment (+) Detail of the intervention Control group: ultrasound guided injection into the subacromial bursa with 40 mg triamcinolone acetonide plus 3 mL of lidocaine Experimental group: ultrasound guided injection into the subacromial bursa and biceps tendon sheath with 40 mg triamcinolone acetonide plus 3 mL of lidocaine Outcome measurement: Visual analogue scale of pain, physical examination(bicipital groove compression test, Speed's test, Yergason's test, empty can test, Neer's impingement test, Hawkins-Kennedy impingement test, painful arc test), range of motion, shoulder pain and disability index (SPADI), shoulder sonography (gray-scale/elastography) Statistical analysis: Continuous variables Student's t test: fit assumption of normal distribution Mann-Whitney test: does not fit the assumption of normal distribution Categorical variables (1) Chi-square test (2) Fisher exact test: sparse data Multivariate analysis: Linear regression Logistic regression Keywords: ultrasonography, corticosteroid, subacromial impingement syndrome, shoulder pain

The treatment is double blind to the participants and outcome assessors. Only the physician performs the injection knows which kind of intervention the patients receive.

Intervention procedure: corticosteroid injection into the subacromial bursa and biceps tendon Device for guidance: high-resolution ultrasound Drug: 40 mg triamcinolone acetonide (a kind of corticosteroid) Intervention procedure: lidocaine injection into the subacromial bursa and biceps tendon Device for guidance: high-resolution ultrasound Drug: 3 mL of lidocaine (the medication will be mixed with 40 mg triamcinolone acetonide)

Intervention procedure: corticoseroid injection into the subacromial bursa only Device for guidance: high-resolution ultrasound Drug: 40 mg triamcinolone acetonide (a kind of corticosteroid) Intervention procedure: lidocaine injection into the subacromial bursa only Device for guidance: high-resolution ultrasound Drug: 3 mL of lidocaine (the medication will be mixed with 40 mg triamcinolone acetonide)

Modified ultrasound guided corticosteroid subacromial injection Standardized ultrasound guided corticosteroid subacromial injection

Shoulder pain and disability index (SPADI). The SPADI contains 13 items that assess two domains; a 5-item subscale that measures pain and an 8-item subscale that measures disability.

The Visual Analogue Scale (VAS) consists of a straight line with the endpoints defining extreme limits such as 'no pain at all' and 'pain as bad as it could be' . The patient is asked to mark his pain level on the line between the two endpoints.

Change in tendon elasticity (strain ratio) after injection. Strain ratio is calculated for the target by selecting a region of interest (ROI) and a corresponding ROI of the adjacent reference tissue. Using machine inherent software, the strain ratio value is displayed on a static image.

Inclusion Criteria: shoulder pain>3 weeks; no contraindication for local injection; Visual analogue scale of pain>4 Exclusion Criteria: systemic rheumatologic disease, Ankylosing spondylitis, malignancy, major trauma or recent injections on the affected shoulder

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Ultrasound-Guided Versus Blind Subacromial Corticosteroid Injections for Subacromial Impingement Syndrome: A Randomized, Double-Blind Clinical Trial. Am J Sports Med. 2016