Nerve Structure - Topography

There are 31 pairs of spinal nerves:        8 Cervical

12 Thoracic

5 Lumbar

5 Sacral

1 Coccygeal

Because of the large number of nerve roots needed to control the upper and lower extrem-ities, the spinal canal in the cervical and lumbar regions is larger than in the thoracic region.

Although there are seven cervical vertebrae, there are actually eight cervical nerve roots. The first cervical nerve root exits between the skull (C0) and C1. the 8th cervical nerve root exits at the same level as the corresponding vertebrae. For example, the L1 nerve root exits between L1 and L2.

The nerve roots branch off the spinal cord higher than their actual exit through the inter-vertebral foramen. This means that the spinal nerves must often pass downwards adjacent to the spinal cord before exiting through the intervertebral forament. This leaves the nerves exposed to risk of compression by protruding disc material. Therefore, it is possible to have a compression of the L5 nerve root at the L4-L5 disc space.

Reference: www.iscoliosis.com, www.brainspine.com.hk

The information provided aims to provide educational purpose, if you have the described conditions as above, please consult your neurosurgeon.

Ligament & Spine

The interspinous ligament connects each adjacent spinous process. The fibers extend from the base to the tip of each spinous process. Anteriorly, the interspinous ligament is adjacent to the ligamentum flavum; posteriorly, it is adjacent to the supraspinous ligament. in the cervical spine, the interspinous ligament becomes part of the ligamentum nuchae, a fibro-membranous ligament posteriorly and cranially to attach to the occiput.

The supraspinous ligament is a very strong band connecting the tips of contiguous spinous processes. It extends from c7 (vertebra prominens) to the sacrum. above c7 these fibers are part of the ligamentum nuchae.

The ligamentum flavum, also called the yellow ligament, consists of elastic fibers oriented vertically that extend from the anterior inferior surface of the lamina above to the superior posterior surface of the lamina below. Unlike the ALL and PLL, the ligamentum flavum is not continuous. There is a small space in the midline between the right and the left fibers. The ligamentum flavum tends to thicken as it progresses down the spine, beginning at the axis (C2) and extending to the sacrum.

Lumbosacral Ligaments

The iliolumbar ligaments extend from the transverse processes of L4 and L5 to the iliac crest.

The lumbosacral ligament is a thick, fibrous band that extends from the anterior-inferior aspect of the trans-verse process of L5 to the lateral surface of the sacrum.

The are two types of SACROILIAC LIGAMENT:

• short sacroiliac ligaments: Composed of horizontal fibers extending from the sacrum to the posterior part of the iliac bone
• long sacroiliac ligaments: Composed of fibers extending vertically from the sacrum to the posterior superior iliac spine

Reference: www.knowyourback.com.

The information provided aims to provide educational purpose, if you have the described conditions as above, please consult your neurosurgeon.

Lower Cervical, Thoracic, and Lumbar Ligaments

The important ligamentous structures of the lower cervical, thoracic, and lumbar spine are discussed below.

The ANTERIOR LONGITUDINAL Ligament (ALL) is composed of thick, longitudinally oriented fibers extending from the axis (C2) anteriorly to the sacrum. The ALL is broader at the level of each vertebral body than at the level of the discs where the fibers adhere to the annulus fibrosus. The ALL attaches to each vertebral body superiorly and inferiorly at the levels of the endplates.

The Intertransverse Ligaments extend from the inferior surface of the entire length of the transverse process to the superior surface of the adjacent transverse process.

The Costalligaments connect the heads of the ribs to the vertebrae.

The POSTERIOR LONGITUDINAL LIGAMENT (PLL) is weaker than the ALL. Its fibers are also longitudinally oriented, but are less dense. It runs from the axis (C2) caudally to the sacrum. The PLL is narrow at the levels of the vertebrae, but the fibers extend laterally at the disc levels. These fibers may help to contain herniated disc material. Like the ALL, the PLL is attached to the vertebra at the superior and inferior margins, and to the annular fibers of the intervertebral disc.

Reference: www.neuropainhk.org

The information provided aims to provide educational purpose, if you have the described conditions as above, please consult your neurosurgeon.

Spine, Nerve structure - Meninges

Within the spinal canal, the spinal cord is surrounded by the EPIDURAL SPACE. This space is filled with fatty tissue, veins, and arteries. The fatty tissue acts as a shock absorber and keeps the spinal cord from contacting the bony tissue of the vertebrae.

The brain and spinal cord are covered by three layers of material, called Meninges. The main function of these layers is to protect and feed the delicate neurological structures.

The DURA MATER is the outermost meningeal layer and is made up of strong connective tissue. Also called the DURA, it is gray in color and generally easy to identify within the spinal canal. The dura extends around each nerve root and becomes contiguous with the EPINEURUM, a membrane covering the spinal nerves

The SUBDURAL SPACE is a very small space between the dura and the next meningeal layer, the ARACHNOID. The arachnoid layer is highly vascularized with a web of arteries and veins that give the impression of a spider wed. It is thinner than the dura and is subject to injury.

Below the arachnoid is the SUBARACHNOID SPACE, which is filled with CEREBROSPINAL FLUID (CSF). The CSF helps to protect the nerve structures by acting as a shock absorber. It also contains various electrolytes, protect, and glucose. A spinal tap can be inserted into the subarachnoid space to retrieve CSF for various chemical analyses.

The innermost lining of the meninges is called the PIA MATER. It is closely adhered to the spinal cord and the individual nerve roots. It is highly vascular and supplies blood to the neuro-logical structures.

Reference: http://www.back.com/

The information provided aims to provide educational purpose, if you have the described conditions as above, please consult your neurosurgeon.

Nerve structure of spinal cord

The Spinal cord functions as a sophisticated network that carries information from the outer elements of the body (skin, muscles, ligaments, joints) through the sensory tracts, to the central “computer,” the brain. Data are processed there, and new information, such as muscle control, is sent out through the motor tracts of the spinal cord. Part of the Central Nervous System (CNS), the spinal cord is located immediately below the brain stem and extends from the foramen magnum to L1.

The spinal cord is a firm but delicate structure that contains both gray and white matter. Compression, distraction, or other manipulation can result in significant injury to the spinal cord.

At L1 the spinal cord terminates as the Conus Medularis. Below L1, the thick but flexible dural sac (also called the thecal sac) contains the spinal nerves collectively known as the CAUDA EQUINA. Also contained within the cauda equina is the FILUM TERMINALE, which extends from the conus medularis to the coccyx and acts as an anchor to keep the lower spinal cord in its normal shape and position.

The individual nerve roots of the cauda equina are suspended in cerebrospinal fluid. At this level, it is possible to pass a needle safely into the thecal sac for evaluation of spinal fluid or injection of various materials such as drugs, anesthetics, or radiologic substances.

Reference: www.back.com, www.brain-spine.com.hk, http://www.necksurgery.com

The information provided aims to provide educational purpose, if you have the described conditions as above, please consult your neurosurgeon.

坐骨神經痛治療 - 水刀手術

椎間盤切除手術是治療腰背痛及坐骨神經痛的方法之一，手術會將壓神經線的髓核組織抽出，但傳統手術5%患者傷及神經，令患者出現腳麻痹等後遺症，痛症復發率更高達10%。香港引入椎間盤水刀技術，用幼細的水柱作手術刀，將突出的髓核組織移除及吸走，傷口僅3至4毫米，手術期間傷及神經線的風險也低於1%。

坐骨神經痛及嚴重腰背痛的成因主要是椎間盤突出，壓神經線，產生痛症。腦外科專科醫生藍明權表示，患者可以接受椎間盤手術，將突出的組織切除，紓緩痛楚。但他指，傳統的手術需要在皮膚上開一個5至6吋的傷口，再放進金屬鉗、刮齒、電熱刀等手術儀器，約5%患者會被儀器及電熱刀傷及神經線，在手術後出現腳麻痹等後遺症，五年內的復發率也高達10%。

香港去年引入最新的椎間盤水刀技術，切除椎間盤組織，藍明權解釋椎間盤水刀分主機、穿刺器及水刀切除器三部份，主機可產生及控制強大高速的水能，經由水刀切除器對椎間盤的組織進行準確的切除，同時吸走切除出來的組織物。

參考資料: www.brain-spine.com.hk

以上所提供的資訊僅作為教育及參考用途，如果你有任何醫療問題，應向神經外科醫生查詢，而不應單倚賴以上提供的資料。

腰椎間盤構造和病變

人類的腰椎是支撐人身體的重要構造。腰椎由多塊稱為椎骨的硬骨和稱為椎間盤的軟組織組成。椎間盤的結構組織,由軟骨板、髓核和纖維環組成,具備緩衝壓力的作用,亦避免椎體之間互相磨擦。椎間盤好像中間填滿啫喱狀物質的車呔。

當椎間盤老化或因為意外受傷，這個”車呔”會出現裂痕，而椎間盤的”啫喱”會從裂痕流出。流出的髓核亦可能壓迫神經線。病人會出現腰背痛或坐骨神經痛。

椎間盤脫位及椎間盤切除手術的後遺症
椎間盤的髓核如果因病變或因手術時大量流失，便會造成椎體之間互相磨擦，最後造成長期背痛，骨刺形成，和坐骨神經痛的復發。傳統椎間盤切除手術病例中復發機會高，復發時間6個月至10年不等。

腰椎間盤核心更換手術
腰椎間盤核心更換手術，是針對此情況而發展的手術。此手術從微創腰椎間盤切除手術的基礎上發展出來的手術。如果病人的髓核因病變已經大量流失或手術時需要切除大量的髓核便可考慮用這新技術。原理是安置一粒特種纖維PEEK制造的圓珠代替髓核，使椎體硬骨不會磨擦，並使脊椎關節保持活動能力。

由於結合多種微創腰椎手術的技術(包括管道微創技術，顯微鏡及儀器，神經線監察技術和X光導巡) 腰椎間盤核心更換手術的傷口比標准椎間盤切除手術的傷口環要細，住院時間環要短，併發症出現機會更低。

參考資料: www.brain-spine.com.hk

以上所提供的資訊僅作為教育及參考用途，如果你有任何醫療問題，應向神經外科醫生查詢，而不應單倚賴以上提供的資料。