Selective denervation of the levator scapulae muscle: an amendment to the Bertrand procedure for the treatment of spasmodic torticollis

OBJECT: The purpose of this cadaveric study was to explore a modification to the Bertrand procedure for the treatment of spasmodic torticollis, namely the denervation of the levator scapulae (LS) muscle for laterocollis. METHODS: The authors performed a series of 9 cadaveric dissections. Five were done to identify the anterior innervation of the LS, and the remaining 4 were to identify the tendinous insertions of the LS onto the lateral masses of the cervical spine via a posterior approach. The nerve supply to the LS from the anterior divisions of the C-3 and C-4 nerve roots and the contribution from the dorsal scapular nerve were identified over the anterior surface of the muscle. RESULTS: The C-3 and C-4 nerve root branches were situated within 2 cm of each other and inferior to the punctum nervosum. The dorsal scapular contribution was clearly identified in 2 cadavers. Selective denervation of this muscle is possible through the same posterior triangle incision used for denervating the sternocleidomastoid muscle of its accessory nerve branches. This approach will be helpful in patients with laterocollis contralateral to the direction of chin turning. The authors compare this approach to the posterior approach for sectioning the insertions of the LS muscle onto the C1-4 posterior tubercles. The latter approach is appropriate for ipsilateral laterocollis. CONCLUSIONS: The posterior triangle approach for denervating the LS muscle is a safe and easy addition to the Bertrand procedure and can be helpful in selected cases of torticollis with a laterocollis component.     

Surgical anatomy of the dorsal scapular nerve

OBJECT: There is a paucity of literature regarding the surgical anatomy of the dorsal scapular nerve (DSN). The aim of this study was to elucidate the relationship of this nerve to surrounding anatomical structures. METHODS: Ten formalin-fixed human cadavers (20 sides) were dissected, and measurements made between the DSN and related structures. The nerve pierced the middle scalene muscle at a mean distance of 3 cm from its origin from the cervical spine and was more or less centrally located at this exit site. It lay a mean distance of 1.5 cm medial to the vertebral border of the scapula between the serratus posterior superior, posterior scalene, and levator scapulae muscles. It was found to have a mean distance of 2.5 cm medial to the spinal accessory nerve as it traveled on the anterior border of the trapezius muscle. The nerve intertwined the dorsal scapular artery in all specimens and was found along the anterior border of the rhomboid muscles. On 19 sides the DSN originated solely from the C-5 spinal nerve, and on one side it arose from the C-5 and C-6 spinal nerves. CONCLUSIONS: Knowledge of the anatomy of the DSN will aid the surgeon who wishes to explore and decompress this structure.     

A cadaveric study of the motor nerves to the levator scapulae muscle

Understanding the surgical anatomic relationships of the motor nerves to the levator scapulae muscle is imperative for reducing postoperative shoulder dysfunction in patients undergoing neck dissection. To elucidate this relevant anatomy, cervical (C3, C4) and brachial (C5 via dorsal scapular nerve) plexi contributions to the levator scapulae were assessed with respect to posterior triangle landmarks in 37 human cadaveric necks. An average of approximately 2 (actual 1.92) nerves from the cervical plexus (range 1 to 4 nerves) emerged from beneath the posterior border of the sternocleidomastoid muscle in a cephalad to caudad progression to enter the posterior triangle of the neck on their way to innervating the levator scapulae. These cervical plexus contributions exhibited a fairly regular relationship to the emergence of cranial nerve XI and the punctum nervosum along the posterior border of the sternocleidomastoid muscle. After emerging from the posterior border of the sternocleidomastoid to enter the posterior triangle of the neck, cervical plexus contributions to the levator scapulae traveled for a variable distance posteriorly and inferiorly, sometimes branching or coming together. Ultimately these nerves crossed the anterior border of the levator scapulae as 1 to 3 nerves (average 1.94) in a regular superior to inferior progression. The dorsal scapular nerve from the brachial plexus exhibited highly variable anatomic relations in the inferior aspect of the posterior triangle, and was found to penetrate or give branches to the levator scapulae in only 11 of 35 neck specimens. We have found that the levator scapulae receives predictable motor supply from the cervical plexus. Our data elucidate surgical anatomy useful to head and neck surgeons. (Otolaryngol Head and Neck Surg 1997;117:671-80.)     

The 2 key muscles in thoracotomy for excision of the lung. The latissimus dorsi and the levator scapulae muscles

Anatomical data related to the thoracotomies performed most frequently in lung surgery are described in some detail: continuity between serratus anterior and levator scapulae as a vide muscular sheet possessing a common deep aponeurosis (thoracolumbar fascia) extending Gilis' space to the vertebral column as the levator scapulae-thoraci space; presence of a "composite aponeurosis" in the posterior angle between serratus anterior and levator scapulae, covering the 8th rib triangle or triangle of auscultation; long costal insertion area and presence of two differently orientated muscle layers for the digitations, particularly of apical bundle. Supplied by a rich vascularization of multiple sources, the serratus anterior and latissimus dorsi are two muscles with single longitudinal nerve pedicles derived from brachial plexus. It is certainly the denervation which is responsible for the distal atrophy of these muscles "sectioned on the right of the selected ribs" following conventional thoracotomy. To avoid esthetic and functional sequelae this innervation must be preserved as far as possible by: interrupting division of serratus anterior anterior to long thoracic nerve and avoiding inclusion of axillary border of latissimus dorsi during lateral thoracotomy; sectioning the latissimus dorsi as low as possible--the other muscles being simply freed and inclined--during lateral thoracotomy.     

Selective peripheral denervation for the treatment of intractable spasmodic torticollis: experience with 168 patients at the Mayo Clinic

OBJECT: Selective peripheral denervation is currently the primary surgical treatment for intractable cervical dystonia. The authors assessed preoperative factors to determine which, if any, correlated with outcomes in patients with torticollis who had undergone this procedure. METHODS: The records of 168 consecutive patients who had undergone selective peripheral denervation for cervical dystonia between 1988 and 1996 at the Mayo Clinic were reviewed. There were 89 women (53%) and 79 men (47%) with a mean age of 53.4 years. Selection of muscles for denervation was based on the patient's clinical presentation and electromyography mapping results. The most common torticollis vectors were rotational in 141 patients (84%) and laterocollis in 59 (35%). Seventy patients (42%) presented with combined vectors. The technique used to remedy both conditions involved denervation of the ipsilateral posterior cervical paraspinal and splenius capitis muscles. Denervation of the sternocleidomastoid muscle was performed on the contralateral side for rotational torticollis and on the ipsilateral side for laterocollis. A rigorous physical therapy program followed surgery. At the 3-month postoperative evaluation, 125 patients (77%) of the 162 who were available for follow up had moderate to excellent improvement in their head position, and pain was moderately to markedly improved in 131 patients (81%). The long-term follow up lasted a mean of 3.4 years and was undertaken in 130 patients. The original level of moderate to excellent improvement in head position and pain was retained in at least 71 patients (70%). Outcome was not predicted by preoperative head position, severity of abnormal posture of head, symptom duration, presence of tremor or phasic dystonic movements, or failure to respond to botulinum toxin treatment. Five patients recovered from postoperative complications including one myocardial infarction, one pulmonary embolism, and three respiratory failures. Three patients suffered from persistent C-2 distribution dysesthesias and three from slight shoulder weakness; one had a wound infection, and one died of respiratory arrest. CONCLUSIONS: Selective peripheral denervation is an effective method of achieving lasting improvement of dystonia in most patients with intractable torticollis.     

Peripheral neurotomy for torticollis: a new approach

Most of spasmodic torticollis is classifical as cervical dystonia and the treatment of choice is chemical or surgical denervation. There are two major procedures for surgical denervation, intradural ventral rhizotomy and extradural peripheral neurotomy (Bertrand procedure). Both have advantages and disadvantages. The authors have modified these procedures to minimize the complications, with unilateral intradural ventral rhizotomy of C1 and C2, extradural denervation of the C3-C6 posterior rami, and contralateral peripheral sectioning of the branches of the spinal accessory nerve to the sternocleidomastoid muscle. 30 patients underwent this modified operation (Group A) and the results were compared with those in a matched control group of 20 patients who underwent the traditional Bertrand procedure (Group B). Only one patient in Group A showed a sensory deficit in the C2 area, while all the patients in Group B had C2 sensory disturbance. Pre- and postoperative rating scores did not differ between the two groups. The intraoperative blood loss was significantly smaller in Group A. Compared with the traditional Bertrand's operation, our procedure involves fewer complications and significantly less intraoperative blood loss.     

脊神经前根选择性切断治疗痉挛性脑性瘫痪

目的了解脊神经前根选择性切断对肢体功能的影响,探讨在痉挛性脑瘫治疗中的应用。方法对健康家犬左侧Ｌ５、Ｌ６及Ｌ７脊神经前根分束选择性切断。对痉挛性脑瘫患者Ｌ２、Ｌ４、Ｌ５及Ｓ１按５０％、２５％、４０％及７５％行选择性切断。结果脊神经前根选择性切断与肌肉有较好对应性,术后共济运动、平衡功能尚好,对应肌张力下降。临床应用３例,近期疗效满意。结论脊神经前根可接受分束选择性切断,在痉挛性脑瘫的治疗中是一种值得探讨的新方法     

胸廓出口综合征手术方法改良

目的 在解剖学研究和临床分析的基础上提出了胸廓出口综合征手术方法的改良。方法 ３０例尸体解剖,研究前、中、小斜角肌的起止点和臂丛神经的关系。随访了术后６个月￣２年的１９例颈肩痛和手部麻木,肌肉萎缩的胸廓出口综合征患者,均做前,中斜角肌起点和小斜角肌切断术。     

Experimental study of denervated muscle atrophy following severance of posterior rami of the lumbar spinal nerves.

The morphologic changes in denervation atrophy of paravertebral muscles after severance of the posterior rami in cats were investigated, using histochemical methods and electromyography. Using a paraspinal approach, three branches of the posterior rami on the left side were cut under microscopy at one, two, or three levels (L2 approximately L4). Muscle atrophy was evaluated, using the percent wet weight and the percent diameter of muscle fibers as parameters. Myosine ATPase stain was used to observe reinnervation. Four weeks after surgery, the range and severity of muscle atrophy increased proportionally to the number of posterior rami severed. Muscle atrophy was revealed at one or two levels caudal to the injured nerve level. At 12 and 24 weeks, muscle atrophy recovered gradually. In more than two-level injury groups, however, recovery of percent wet weight reached up to 80% even after 24 weeks, despite the fact of reinnervation demonstrated in some parts of the denervated muscles.     

Electromyographic findings in patients with low back pain due to unsuspected primary and metastatic spinal or paraspinal muscle disease

Electromyographic studies were performed on 16 patients with intractable low back pain and no antecedent history of malignancy or metastatic disease. In each case, electromyographic evidence of severe segmental denervation limited to the paraspinal muscles innervated by the posterior primary rami was found. Subsequent diagnostic studies in each patient revealed a primary neoplasm or tumor metastasis as the source of pain. Applying current knowledge of neuromuscular physiology, the electromyograph may prove to be a valuable aid to the early detection of remote metastasis to the spine and paraspinal muscle structures.     

The innervation of the lumbar spine

The lumbar intervertebral discs are innervated posteriorly by the sinuvertebral nerves, but laterally by branches of the ventral rami and grey rami communicantes. The posterior longitudinal ligament is innervated by the sinuvertebral nerves and the anterior longitudinal ligament by branches of the grey rami. Lateral and intermediate branches of the lumbar dorsal rami supply the iliocostalis lumborum and longissimus thoracis, respectively. Medial branches supply the multifidus, intertransversarii mediales, interspinales, interspinous ligament, and the lumbar zygapophysial joints. The distribution of the intrinsic nerves of the lumbar vertebral column systematically identifies those structures that are potential sources of primary low-back pain.     

Patterns of oculomotor nerve distribution to the levator palpebrae superioris muscle, and correlation to temporary ptosis after blepharoplasty

Transient diplopia, blepharoptosis, or both conditions are rare postoperative complications of blepharoplasty performed with the patient under local anesthesia. It has been hypothesized that some cases of postoperative diplopia and blepharoptosis could be attributed to the myotoxic effects of local anesthetics to the extraocular muscles and the levator muscle or to the neurotoxic effects of lidocaine. In 30 cadavers, the superior division of the oculomotor nerve was severed en bloc 1.5 cm anterior to the annulus of Zinn with the levator palpebrae superioris (LPS) and the superior rectus muscles. These muscles were detached from their origins, and their attachments to the scleral and tarsal plates were divided respectively. The specimens were treated in guanidine-hydrochloride and Alizarin Red solution, and were dissected under an operating microscope. The nerve branches of the superior division of the oculomotor nerve innervated the proximal third (type I) in 2 of 30 LPS muscles (6.7%), in 8 of 30 muscles (26.7%) extended to the middle third (type II), and reached the distal third (type III) in 20 of 30 muscles (66.7%). The terminal branches ran through the medial third (type IIIa) in 6 of 20 type III LPS muscles (30%), the central third (type IIIb) in 8 muscles(40%), and the lateral third (type IIIc) in 6 muscles (30%). The oculomotor nerve ends that extend forward to the distal third of the LPS muscle (type III) are exposed and vulnerable to local anesthetics and may be numbed during blepharoplasty. If this is so, postoperative blepharoptosis may be caused by transient paralysis of the LPS muscle, and great care should be taken during the injection of local anesthetics near the LPS.     

The anatomic branch pattern of the axillary nerve

The purpose of this study is to determine the surgical anatomy and innervation pattern of the branches of the axillary nerve and discuss the clinical importance of the presented findings. We dissected 30 shoulders in 15 fixed adult cadavers under a microscope through anterior and posterior approaches. The axillary nerve was examined in 2 segments in relation to the underlying subscapularis muscle. The axillary nerve gave off no branches in the first segment in 85% of cases. When the posterior approach was used, the axillary nerve and its branches were observed to be in a triangular-shaped area. The mean distance from the posterolateral corner of the acromion to the axillary nerve and its branches was 7.8 cm. In all cases, the posterior branch of the axillary nerve gave off its first muscular branch to innervate the teres minor. The joint branch of the axillary nerve was observed to branch out in 3 different patterns. The acromial and clavicular parts of the deltoid muscle were observed to be innervated from the anterior branch of the axillary nerve in all cases. The posterior part of the deltoid muscle was observed to be innervated in 3 different patterns. The posterior part of the deltoid was innervated from the branch or branches coming only from the posterior branch in 70% of cases, from the anterior and posterior branches in 26.7% of cases, and from the anterior branch in 3.3% of cases. The findings of this study are useful for identifying each of the branches of the axillary nerve and have implications for surgeries related with selective innervation.     

Successful restoration of the trapezius muscle using pedicle latissimus dorsi. A case report

Reconstruction of the trapezius muscle using a pedicle latissimus dorsi flap was performed in a 27-year-old man with a large synovial sarcoma in his shoulder girdle. Size and location of the tumor required combined resection of surrounding muscles, including the trapezius, levator scapulae, and rhomboid major and minor. Thus, an extensive defect of the suspending muscles of the scapula was created after accomplishing an adequate resection of the tumor. The flap was performed to restore the trapezius functionally because there were no adjacent muscles available. The transferred muscle compensated for loss of the trapezius, thereby recovering excellent shoulder function. Although an opportunity of its application is thought to occur infrequently, the pedicle latissimus dorsi can activate scapular motion successfully in the absence of the levator scapulae. The technique may be extended to salvage failed conventional reconstruction after spinal accessory nerve palsy.     

Lateral parascapular extrapleural approach to the upper thoracic spine

The upper thoracic vertebrae are difficult to approach surgically because of the narrowing of the thoracic inlet, the proximity of the brachial plexus, and the parascapular shoulder musculature. A novel lateral parascapular extrapleural approach to the upper thoracic vertebrae is described. The parascapular shoulder musculature (trapezius, levator scapulae, and rhomboid muscles) is reflected off the spinous processes to the scapula as a musculocutaneous flap, preserving the neurovascular supply. The paraspinal musculature is mobilized and retracted, and the upper dorsal ribs are removed with caution to avoid injury to the C-8 and T-1 nerve roots. The rami communicantes are transected, and the sympathetic chain is displaced anterolaterally. The T2-4 vertebrae can be approached unobstructed. The T-1 nerve root obstructs posterolateral access to the T-1 vertebra, necessitating an inferolateral approach underneath the T-1 nerve root axilla. Four patients with compressive myelopathy from upper thoracic vertebral metastases underwent neural decompression, vertebral reconstruction, and posterior spinal fixation with this approach. Their postoperative neurological status was either unchanged or improved. Complications included radiographic pleural effusion and superficial wound dehiscence; one patient required posterior spinal reinstrumentation for progressive kyphosis. One patient developed pneumonia 7 days postoperatively which was unresponsive to appropriate treatment. It is believed that the anatomical limitations to this region have been overcome, and that excellent exposure of the T1-4 vertebrae for neural decompression and vertebral reconstruction can be performed safely. A major advantage is that posterior spinal fixation can be carried out simultaneously.     

Transaxillary endoscopic release of restricting bands in congenital muscular torticollis--a novel technique.

Congenital muscular torticollis is due to fibrosis of one or both the heads of sternocleidomastoid muscle. This may also involve the platysma, scalene muscles, and the carotid sheath and may be associated with cervical scoliosis. Conventional surgical procedures leave visible scars. Ramirez, who used the posterior part of the traditional face-lift incision, made perhaps the first attempt at concealing scars. Burstein et al. reported a large series of subcutaneous endoscopic release of torticollis through a hairline approach. Sasaki described an endoscopic two-incision, posterior auricular fold and hairline approach. A technique of transaxillary subcutaneous endoscopy for the release of the sternocleidomastoid muscle in congenital muscular torticollis is described here. This procedure provides direct access to the fibrous bands, enables release without risk of damage to the spinal accessory nerve, external jugular vein, or greater auricular nerve, and leaves no visible neck scars. Two cases of congenital muscular torticollis presenting in adulthood were managed successfully by this technique. The fibrotic part of sternocleidomastoid muscle was released and the normal range of head motion was restored. There were no surgical complications encountered and the patients achieved complete pain free range of movement in six weeks. This technique provides direct and quick access, perpendicular to the line of the fibrotic bands, avoids injury to neurovascular structures and does not leave visible neck scars.     

内窥镜诊治臂丛神经血管受压征手术器械入路的解剖学研究

目的探讨应用内窥镜诊治臂丛神经血管受压征的可行性,在锁骨下内窥镜入路的基础上,在腋部寻找到达第一肋表面前中斜角肌止点的手术器械安全入路,为临床应用奠定基础。方法取陈旧尸体标本2具4侧,新鲜尸体标本9具18侧。在腋窝胸大肌后缘第二肋水平做1.5cm长皮肤横切口,采取不同体位,于不同角度测量自入路切口点到第一肋表面前中斜角肌止点的距离,解剖肋锁间隙、入路周围的组织结构及相互的毗邻关系,选择安全器械入路。结果侧卧位,上肢外展上举120°、前倾30°,取胸大肌后缘第二肋水平1.5cm皮肤横切口,器械沿胸壁向胸锁关节外侧6.5cm处插入7.8cm左右,顺利到达第一肋表面前中斜角肌止点,自皮肤至第一肋的走行中不伤及血管、神经。结论该手术入路是器械到达第一肋表面前中斜角肌止点的安全入路。     

Anatomical reasons for problems after neurectomy for blepharospasm: a study in cadavers.

The purpose of this study is to clarify the mechanisms of the problems that develop after neurectomy for blepharospasm. The left facial nerves in 10 Japanese cadavers were dissected under a surgical microscope. The temporal, zygomatic, and buccal branches innervated to the orbicularis oculi muscle. These three groups formed a well-communicating plexus posterior to the orbicularis. The most inferior buccal branch curved in the deep layer in the lower part of the cheek. In the cheek, both the buccal and the temporal branches had ramifications of other facial muscles. The information given in previous anatomical textbooks did not specifically define the denervation of the orbicularis. When neurectomy was done in the past, the inferior buccal branch may have been kept intact, or other facial muscles as well as the orbicularis may have been denervated which caused the blepharospasm to recur and complications to develop after neurectomy.     

ANATOMICAL REASONS FOR PROBLEMS AFTER NEURECTOMY FOR BLEPHAROSPASM: A STUDY IN CADAVERS

The purpose of this study is to clarify the mechanisms of the problems that develop after neurectomy for blepharospasm. The left facial nerves in 10 Japanese cadavers were dissected under a surgical microscope. The temporal, zygomatic, and buccal branches innervated to the orbicularis oculi muscle. These three groups formed a well-communicating plexus posterior to the orbicularis. The most inferior buccal branch curved in the deep layer in the lower part of the cheek. In the cheek, both the buccal and the temporal branches had ramifications of other facial muscles. The information given in previous anatomical textbooks did not specifically define the denervation of the orbicularis. When neurectomy was done in the past, the inferior buccal branch may have been kept intact, or other facial muscles as well as the orbicularis may have been denervated which caused the blepharospasm to recur and complications to develop after neurectomy.     

Surgical anatomy of the upper vertebral artery

Summary A surgical approach to the upper vertebral artery between C₁ and C₂ is described. Following dissection of the posterior border of the sternocleidomastoid and the anterior border of the splenius capitis the two muscles are held apart and the levator scapulae is transsected at its origin from C₁. The cranial end of the vertebral artery can now be connected with the common carotid or external carotid arteries.