Comparison of the Efficacy of Two Different Suprascapular Nerve Block Techniques in Patients With Chronic Shoulder Pain

Comparison of the Efficacy of Two Different Suprascapular Nerve Block Techniques in Patients With Chronic Shoulder Pain

Comparison of Efficacy and Safety of Two Different Ultrasound-Guided Suprascapular Nerve Block Techniques in Chronic Shoulder Pain: A Prospective Double-Blinded Randomized Controlled Study

The aim of this study is to compare the efficacy and safety of the suprascapular nerve block (SSNB) at the spinoglenoid notch with SSNB at the suprascapular notch, which is the most commonly used technique in patients with chronic shoulder pain.

Chronic shoulder pain (>3 months) is one of the most common musculoskeletal problems leading to psychosocial problems. Its causes include subacromial impingement, tendinosis, calcific tendinitis, complete or partial tendon tears, adhesive capsulitis, subacromial bursitis, glenohumeral osteoarthritis, glenohumeral instability, and acromioclavicular joint pathologies. For the treatment of chronic shoulder pain, conservative or surgical methods can be applied. Suprascapular nerve block (SSNB) is an effective and safe treatment option for pain relief and increases in functional activity in these patients. The suprascapular nerve (SSN) is a peripheral nerve has both motor and sensory fibers, originates from the ventral rami of C5-C6 nerve roots. SSN passes across the posterior triangle of the neck and through the suprascapular notch enters to the supraspinous fossa. Then it comes to the infraspinous fossa via the spinoglenoid notch. The SSN has 3 sensory branches: a medial subacromial branch passes to the suprascapular notch, a lateral subacromial branch and a posterior glenohumeral branch pass the spinoglenoid notch. These branches supplies 70% of the sensory input to the shoulder. In the literature, SSNB through suprascapular notch has positive effect on shoulder functions, pain and range of motion (ROM) in patients in the treatment of chronic shoulder pain. There is no study examining the efficacy of SSNB through spinoglenoid notch in the treatment of chronic shoulder pain.Therefore, the investigators planned this randomized trial to compare of the efficiency and safety of two different SSNB techniques (approach through suprascapular notch versus spinoglenoid notch) in treatment of patients with chronic shoulder pain. Material and methods: Participants: adult patients (>18 year old) with chronic shoulder pain Inclusion criteria: age ≥ 18 years old, shoulder pain that last more than 3 month, patients with a vas value of ≥ 4 despite treatment (drugs used for analgesia, local injections and physiotherapy methods), shoulder pain defined as non-specific shoulder pain, subacromial impingement syndrome, rotator cuff tendinopathy, adhesive capsulitis, non-traumatic instability, superior labrum anterior and posterior (SLAP) lesion, acromioclavicular pathology, shoulder osteoarthritis. Exclusion criteria: A history of uncontrolled chronic diseases, e.g., malignant neoplasms, blood dyscrasia, previous surgery history at the affected shoulder, shoulder injection in the last 3 months before treatment, cervical radiculopathy or myelopathy, a previous fracture close to the shoulder region, septic arthritis or local infection in the affected shoulder, anaphylaxis against local anesthetics and/or corticosteroids, cardiac pacemaker, pregnancy. Study Design: prospective, double blind, non-inferiority, randomized controlled trial Randomization method: 1:1 by computer randomization program Detail of the intervention: Experimental: SSNB through the spinoglenoid notch US guided 1ml methylprednisolone acetate (1ml / 40mg) and 5ml 0.5% bupivacaine Intervention: Medication: corticosteroids and local anesthetics Active comparator: SSNB through the suprascapular notch US guided 1ml methylprednisolone acetate (1ml / 40mg) and 5ml 0.5% bupivacaine Intervention: Medication: corticosteroids and local anesthetics Outcome measurement: Visual analogue scale of pain, active range of motion, shoulder pain and disability index (SPADI), Pain Pressure Threshold (PPT), Patient satisfaction Statistical analyses: Sample size calculation: The sample size was calculated using http://statulator.com/SampleSize/ss2M.html considering a previous study. The non-inferiority margin for SPADI was taken as 9 points. Standard deviation 15.3 (assuming normal distribution) with a power of 80, an error of 0.05 type 1; 36 patients should be enrolled per groups. Including a rate of 10% drop-out 40 patients were planned to enroll in each groups. 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 The outcome differences within the experimental and active comparator groups of different time of evaluation will be analysed by using repeated-measures analysis of variance (ANOVA) with post hoc test with Bonferroni method.

US guided 1ml methylprednisolone acetate (1ml / 40mg) and 5ml 0.5% bupivacaine Intervention: Medication: corticosteroids and local anesthetics

US guided 1ml methylprednisolone acetate (1ml / 40mg) and 5ml 0.5% bupivacaine Intervention: Medication: corticosteroids and local anesthetics

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.

Visual analogue score (VAS) was done at rest and at shoulder movement. VAS was explained to the patients during assessment as 0 equal no pain and 10 equal worst imaginable pain.

Active ROM of the affected shoulder is measured using a goniometer. These measurements included abduction, flexion, internal rotation, and external rotation.

In order to determine the pain perception thresholds in the affected shoulder, Pain Pressure Threshold (PPT) values will be calculated by taking three measurements from the middle deltoid, upper trapezius, infraspinatus and tibialis anterior area with an algometer (Commander Echo® Algometer, JTECH Medical, Midvale, UT, USA). The average of the last 2 measurements will be taken and recorded.

Patient satisfaction with the injection is determined by Likert Scale (1= very dissatisfied, 2= dissatisfied, 3=neither dissatisfied or satisfied, 4= satisfied, 5= very satisfied)

Inclusion Criteria: Age ≥ 18 years old Shoulder pain that last more than 3 month Patients with a VAS value of ≥ 4 despite treatment (drugs used for analgesia, local injections and physiotherapy methods) Shoulder pain defined as non-specific shoulder pain, subacromial impingement syndrome, rotator cuff tendinopathy, adhesive capsulitis, non-traumatic instability, SLAP lesion, acromioclavicular pathology, and / or shoulder osteoarthritis. Exclusion Criteria: A history of uncontrolled chronic diseases, e.g., malignant neoplasms, blood dyscrasia, and infection Previous surgery history at the affected shoulder Shoulder injection in the last 3 months before treatment The presence of cervical radiculopathy or myelopathy A previous fracture close to the shoulder region Presence of septic arthritis or local infection in the affected shoulder Presence of anaphylaxis against local anesthetics and / or corticosteroids Presence of a cardiac pacemaker Pregnancy

Saglam G, Alisar DC. A Comparison of the Effectiveness of Ultrasound-Guided Versus Landmark-Guided Suprascapular Nerve Block in Chronic Shoulder Pain: A Prospective Randomized Study. Pain Physician. 2020 Nov;23(6):581-588.

Chan CW, Peng PW. Suprascapular nerve block: a narrative review. Reg Anesth Pain Med. 2011 Jul-Aug;36(4):358-73. doi: 10.1097/AAP.0b013e3182204ec0.

Laumonerie P, Blasco L, Tibbo ME, Bonnevialle N, Labrousse M, Chaynes P, Mansat P. Sensory innervation of the subacromial bursa by the distal suprascapular nerve: a new description of its anatomic distribution. J Shoulder Elbow Surg. 2019 Sep;28(9):1788-1794. doi: 10.1016/j.jse.2019.02.016. Epub 2019 Apr 26.

Vorster W, Lange CP, Briet RJ, Labuschagne BC, du Toit DF, Muller CJ, de Beer JF. The sensory branch distribution of the suprascapular nerve: an anatomic study. J Shoulder Elbow Surg. 2008 May-Jun;17(3):500-2. doi: 10.1016/j.jse.2007.10.008. Epub 2008 Feb 11.

Chang KV, Hung CY, Wu WT, Han DS, Yang RS, Lin CP. Comparison of the Effectiveness of Suprascapular Nerve Block With Physical Therapy, Placebo, and Intra-Articular Injection in Management of Chronic Shoulder Pain: A Meta-Analysis of Randomized Controlled Trials. Arch Phys Med Rehabil. 2016 Aug;97(8):1366-80. doi: 10.1016/j.apmr.2015.11.009. Epub 2015 Dec 14.

Shanahan EM, Ahern M, Smith M, Wetherall M, Bresnihan B, FitzGerald O. Suprascapular nerve block (using bupivacaine and methylprednisolone acetate) in chronic shoulder pain. Ann Rheum Dis. 2003 May;62(5):400-6. doi: 10.1136/ard.62.5.400.