Levatores Costarum Interspinales And Intertransversarii





Intertransversarii, Interspinales, Levatores Costarum What are the (deep layer) intrinsic back muscles? Transversospinalis (Semispinalis, Multifidus, Rotatores brevis/longus).

  • The intertransversarii musculi are small muscles that pass between transverse processes, between articular and transverse processes or between mamillary and transverse processes. They are separable into different groups: Intertransversarii lumborum: medial bundles run ventrocranially from mamillary processes to transverse (or accessory) processes.
  • Lateral flexors of the vertebral column (10) back 29. Intertransversarii and levatores costarum. Intertransversarii: posterior and anterior.
Levatores
Alejandro Marquez-Lara

Kern Singh
Levatores Costarum Interspinales And IntertransversariiLevatores Costarum Interspinales And Intertransversarii

Interspinales Muscle





  • Superficial landmarks enable gross determination of the anatomic level. Proximally, C7 and T1 are the largest spinous processes and may serve as palpable anatomic landmarks. Distally, the intercrestal line approximates the L4-L5 interspace.


  • There are three layers to the posterior musculature of the spine (FIG 1; Table 1):



    • Superficial layer: trapezius, latissimus dorsi, rhomboid major and minor, and the levator scapulae


    • Intermediate layer: superior and inferior serratus posterior and the levatores costarum


    • Deep layer: erector spinae, transversospinalis, interspinalis, and the intertransversarii


  • The superficial and intermediate layers receive their nervous supply from peripheral nerves, which are not encountered through the posterior approach (FIG 2). The deep layer receives its nervous supply segmentally from the posterior dorsal rami. There is a large amount of redundancy in the innervation of the deep layer.



    • The midline approach is a true internervous plane. Nerve injury occurs only with excessive lateral dissection.


  • The vascular supply to the deep layer is from segmental branches of the aorta. These vessels enter the operative field at the level of the intertransverse ligament and can be a source of significant bleeding.


  • The facet joint capsules have a shiny white appearance and the individual fibers can be seen inserting onto the lateral edge of the laminar trough. Care should be taken to avoid violating the capsular fibers, unless that segment is being fused.


  • The ligamentum flavum has a yellow appearance with the fibers running in a cephalocaudal direction. The cephalad end of the ligament has a broad insertion from the base of the spinous process to between 50% and 70% of the anterior surface of the lamina. The caudal end of the ligament inserts from the superior edge of the lamina to between 2 and 6 mm of the anterior surface of the lamina.4


  • Particularly at the L5-S1 level, the interspace may be widened or the posterior bony anatomy only partly formed. Care should be exercised when exposing this level as inadvertent plunging into the canal may occur.


  • Laterally, the intertransverse membrane overlies the iliopsoas and protects the neural structures that lie beneath.


  • In children, the spinous process apophysis has not fused. During dissection, the apophysis is split down to the bone and then elevated with the paraspinal musculature.



FIG 1 • The superficial, intermediate, and deep musculature of the back.
Levatores Costarum Interspinales And Intertransversarii




Muscle


Origin


Insertion


Innervation


Blood Supply


Superficial layer


Trapezius


Medial third of superior nuchal line of occiput, external occipital protuberance, and ligamentum nuchae; spinous processes of C7-T12


Lateral third of clavicle, acromion, spine of scapula


Motor supply from spinal accessory nerve, sensory fibers from C3 to C4


Transverse cervical artery


Latissimus dorsi


Spinous processes of T7—sacrum, medial third of iliac crest, ribs 9-12, inferior angle of scapula


Floor of bicipital groove


Thoracodorsal nerve (C7, C8)


Thoracodorsal artery


Levator scapulae


Transverse processes of C1-C4


Medial border of scapula


Dorsal scapular nerve (C5), with branches of C3-C4 innervating upper part of muscle


Dorsal scapular artery


Rhomboid major


Spinous processes of T2-T5


Medial border of scapula


Dorsal scapular nerve (C5)


Dorsal scapular artery


Rhomboid minor


Caudal end of ligamentum nuchae, spinous processes of C7-T1


Medial border of scapula


Dorsal scapular nerve (C5)


Dorsal scapular artery


Intermediate layer


Serratus posterior superior


Spinous processes of C7-T3


Ribs 1-4


Intercostal nerves


Posterior intercostals arteries of T1-T4


Serratus posterior inferior


Thoracolumbar fascia, spinous processes of T11-L2


Ribs 9-12


Intercostal nerves


Posterior intercostal arteries, subcostal artery, and L1-L2 lumbar arteries


Levatores costarum


Tip of transverse process of C7-T11 vertebrae


Rib below level of origin


Posterior rami of thoracic spinal nerves


Dorsal intercostal arteries


Deep layer


Erector spinae (vertically oriented and superficial)


Iliocostalis Longissimus Spinalis


Iliac crest, sacrum, transverse and spinous processes of vertebrae, and supraspinal ligament


Ribs, transverse and spinous processes of vertebrae, posterior aspect of skull


Segmental innervation by dorsal primary rami of spinal nerves C1-S5


Segmental supply by deep cervical arteries, posterior intercostal arteries, subcostal artery, and lumbar arteries


Transversospinalis (obliquely oriented and intermediate)


Semispinalis


Transverse processes T1-T12


Spinous processes of C2-T5


Dorsal rami of spinal nerves


Segmental arteries from aorta


Multifi


dus Articular processes of cervical vertebrae, transverse processes of thoracic vertebrae, mammillary processes of lumbar vertebrae, posterior superior iliac spine


Spinous processes of C2-L5


Dorsal rami of spinal nerves


Segmental branches from aorta


Rotatores


Transverse processes


Base of spinous processes above Long skip one level; short attach at level above


Dorsal rami of spinal nerves


Segmental branches from aorta


Deepest muscle


Interspinales


Spinous processes


Spinous processes one level above


Dorsal rami of spinal nerves


Segmental branches from aorta


Intertransversarii


Anterior and posterior transverse processes of cervical vertebrae, transverse and mammillary processes of lumbar vertebrae


Anterior and posterior processes of cervical vertebrae one level above, transverse and accessory processes of lumber vertebrae one level above


Dorsal rami of spinal nerves


Segmental branches from aorta

Levatores costarum brevis
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