Trapezius Muscle

Patients in the PVB and RIB groups were intervened by ultrasound-guided nerve block in the lateral position with local anesthesia. The PVB was performed using the in-plane technique with a linear 4–10 MHz ultrasound probe (LOGIQe, GE Healthcare, Waukesha, WI., U.S.A.). At the parasagittal view, subcutaneous tissues, T5 transverse processes, superior costotransverse ligament (SCTL), and pleura were visualized. An 18 G block needle was inserted vertically or slightly caudally into the paravertebral space (PVS) under the guidance of ultrasound. After the penetration of the SCTL, a slight aspiration was performed to ensure the avoidance of vessels or pleura. Then, 1–2 ml of normal saline was injected into the PVS, the pressure of which pushed down the pleura. The position of the needle tip was confirmed, and 0.4% ropivacaine (Zhejiang Xianju Pharmaceutical Co., Ltd., Zhejiang, China) at 3 mg/kg was injected into the PVS.
A linear 4–10 MHz ultrasound probe (LOGIQe, GE Healthcare, Waukesha, WI, U.S.A.) was placed on the medial border of the scapula between the 4th and 5th rib of the patients in the RIB group. In the ultrasound image, the trapezius muscle, rhomboid muscle, intercostal muscles, pleura, and lung were identified. Under the aseptic condition, an 18 G block needle was inserted laterally in the plane of the T5 level guided by an ultrasound probe with an in-plane technique. The vessel injection should be confirmed negative through aspiration, and 1–3 ml of normal saline was injected to divide the rhomboid and intercostal muscle, and 0.4% ropivacaine at 3 mg/kg was injected into the deep layer of the rhomboid muscle.

Method
Cadaveric examination in one cadaver was performed following approval from Istanbul Medipol University Ethics and Research Committee (Date: 13/04/2022, No: 327). The same committee also approved (Date: 11/05/2022, No: 437) the retrospective evaluation of five patients that underwent SPSIP between 15/04/2022 and 11/05/2022. All patients gave written informed consent for inclusion of their data in this study.
Description of SPSIP block
Although we prefer the prone position for the block, it can also be performed in the sitting position. To lateralize the scapula, the patient is instructed to grip the opposing shoulder with the hand on the side where the block is to be performed or to put the affected arm into adduction and internal rotation. A high frequency (4-12 MHz) linear transducer (B-Braun, Philips, Xperius, USA) is placed at the spinae scapula level in the transverse plane, and the upper medial border of the scapula, the trapezius muscle, Rm, SPSM and the second and third ribs are visualized. The ultrasound probe is rotated 90 degrees in a parasagittal orientation from the posterior aspect of the supraclavicular fossa to identify the first rib. After its identification, the second and third ribs are confirmed. The linear transducer is then rotated so that an oblique visualization is obtained (inferomedial-superolateral) with the upper medial border of the scapula in the sonographic view (Figure 1A). The needle (Stimuplex® Ultra 360®, B-Braun, Melsungen, Germany) is then advanced immediately medial to the scapula, aiming for the area between the second and third ribs in order to reach the fascial plane between the SPSM and intercostal muscles, either in the in-plane (caudal to cephalad) or out of the plane technique. After contact of the needle with the rib gently, 1-2mL of saline is used to confirm the correct plane, and a total of 30 mL of local anesthetic (LA) agent is administered to the superficial to the intercostal muscle. The LA should be visible, spreading cephalad and caudad over successive ribs in the interfascial plane (Figure 1B). Schematic illustration at the level of third rib demonstrating needle/probe position and injectate spread during SPSIP is seen in Figures 1C, D.
Anatomic study of the SPSIP block
Bilateral SPSIP block was performed to an unembalmed cadaver. There were no surgical incisions or scars in the paraspinal region and thorax/neck/shoulder/upper abdominal regions of the cadaver, nor were there any anatomical deformities on inspection. The cadaver was maintained at room temperature for 12 hours prior to block application. Thirty mL of methylene blue 0.5% was administered to each side using the in-plane technique (ST-HAA). One hour after administration, an experienced anatomist (AF) began dissection. Beginning at C7 and proceeding dorsally to T10, the skin, and fascia were dissected from the midline. Both sides were simultaneously dissected and compared with each other. The trapezius muscle, latissimus dorsi, rhomboids, and erector spinae muscles were dissected and evaluated for the presence of dye. After dissecting the rhomboid muscles away from the midline, the scapula and its superficial and deep muscles were shifted laterally without making a transverse incision in order to analyze the distribution of dye along the intercostal muscles. The intercostal muscles were subsequently dissected in the sagittal plane to assess the presence of dye within the muscles. To evaluate dye distribution, the deep fascia of the trapezius muscle was traced to the scapula. To define the anterior boundary of dye spread, vertical incisions were made at the posterior, middle, and anterior axillary lines.
Case series
Considering the cadaveric findings, the SPSIP block application was chosen for eligible individuals who were likely to benefit from this new block technique. All of these patients were selected from patients who were diagnosed with myofascial pain syndrome (MPS), which causes complaints in the cervical and interscapular region, according to MPS diagnostic criteria, and who had previously been treated with medications, physiotherapy, and neural therapy for this, but could not provide sufficient pain relief.
After informing patients of the risks, benefits, and alternatives of this procedure, all patients provided informed written consent. The block was performed in the prone position under sterile conditions and after administration of 2% lidocaine for local anesthetic infiltration of the skin. Dermatomal evaluation was performed 40 minutes after block administration using the cold test.

All clavicles were scanned with IQon Spectral Computed Tomography (CT) (Philips Healthcare, Netherlands) at the University Hospital of Miyazaki (Miyazaki, Japan). A 3D model of the clavicles was reconstructed from CT data using the application software MIMICS 23.0 (Materialise, Leuven, Belgium). Using these data, the bone surface configuration concerning the insertion area of the muscles and the non-attachment area from the model were evaluated.
Generally, a medical device is used to fix clavicle fractures. We selected two types of plates: the anterior plate (VA-LCP Anterior Clavicle Plate, 10 holes, 101 mm, Synthes^®, Tokyo, Japan) and the superior plate (LCP Superior Clavicle Plate, 7 holes, 110 mm, Synthes^®, Tokyo, Japan), the lengths of which were sufficient to cover three or more holes in the proximal and distal parts. Three-dimensional templating was performed on both the superior and anterior clavicle plates using CT data (Fig. 1B). The area of coverage by the anterior and superior plates on the sternocleidomastoid, trapezius, pectoralis major, and deltoid muscles were measured using Materialise 3-matic 15.0 software (Materialise, Leuven, Belgium). The areas covered by these muscles were measured using the following formula: medial length × lateral length and were evaluated statistically.