The Proximal Approach in an Ultrasound-Guided Suprascapular Nerve Block / 대한정형외과학회잡지

PURPOSE: The purpose of this study was to analyze any effectiveness, advantages, and the procedure of an ultrasound-guided suprascapular nerve block via the proximal approach in patients suffering from shoulder pain. MATERIALS AND METHODS: A total of 51 patients treated with nerve block between November 2015 and November 2016 were analyzed. We identified the suprascapular nerve that branches off the superior trunk of the brachial plexus, and found the suprascapular nerve, which is located in the fascial layer between the inferior belly of the omohyoid muscle and the serratus anterior muscle. We then performed a nerve block. We evaluated the visual analogue scale (VAS) of pre- and post-nerve block, and the visualization of the nerve, depth from the skin to the nerve, angle of needle entry, as well as complications. Moreover, we measured the visualization of the nerve, depth from the skin to the nerve in a classic approach, and compared it with the proximal approach. RESULTS: There was significant improvement (p < 0.05) in the mean VAS, from 7.1 to 3.4, without any major complications. Compared with the classic approach, we were able to identify the suprascapular nerve much better (classic 25.5%/proximal 96.1%), and the mean distance from the skin to the nerve (classic 38 mm/proximal 12 mm) was significantly short (p < 0.05), and the mean angle of needle entry was 19 degrees in the proximal approach. CONCLUSION: In an ultrasound-guided suprascapular nerve block by proximal approach, the nerve and needle tip can be more easily identified, which increases accuracy; with a small amount of local anesthetic, more effective pain control can be achieved. Hence, this approach is an effective alternative pain control method for patients suffering from shoulder pain.

Variation of the Infrahyoid Muscle: Duplicated Omohyoid and Appearance of the Levator Glandulae Thyroideae Muscles

The embryologic origin of the omohyoid muscle is different from that of the other neck muscles. A number of variations such as the absence of muscle, variable sites of origin and insertion, and multiple bellies have been reported. However, variations in the inferior belly of the omohyoid muscle are rare. There have been no reports of the combined occurrence of the omohyoid muscle variation with the appearance of the levator glandulase thyroideae muscle. Routine dissection of a 51-year-old female cadaver revealed a duplicated omohyoid muscle and the appearance of the levator glandulae thyroideae muscle. In this case, the two inferior bellies of the omohyoid muscle were found to originate inferiorly from the superior border of the scapula. One of the inferior bellies generally continued to the superior belly with the tendinous intersection. The other inferior belly continued into the sternohyoid muscle without the tendinous intersection. In this case, the levator glandulae thyroideae muscle appeared on the left side, which attached from the upper border of the thyroid gland to the inferior border of the thyroid cartilage. These variations are significant for clinicians during endoscopic diagnosis and surgery because of the arterial and nervous damage due to iatrogenic injuries. The embryologic origins of the omohyoid and levator glandulae thyroideae muscles may be similar based on the descriptions in the relevant literature.