What is a Lumbar Laminectomy?

Lumbar disc herniation is a common cause of low back pain. Based on the degeneration of the lumbar intervertebral disc, the injury of the waist can easily cause the nucleus pulposus and the damaged fibrous ring tissue to protrude backward, compressing the nerve root and causing a series of clinical manifestations.

Lumbar disc herniation

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Lumbar disc herniation is a common cause of low back pain. Based on the degeneration of the lumbar intervertebral disc, the injury of the waist can easily cause the nucleus pulposus and the damaged fibrous ring tissue to protrude backward, compressing the nerve root and causing a series of clinical manifestations.

Chinese name

Lumbar disc herniation

There are many causes of sciatica, and sometimes it is difficult to diagnose. Clinically, lumbar tuberculosis or other diseases were misdiagnosed as disc herniation and surgically performed; others were diagnosed as disc herniation before surgery, but nothing was found during the operation; although some cases can be explained by the nucleus pulposus retraction under anesthesia However, it also explains the complexity of diagnosis; in addition, spinal canal, crypt, and root canal stenosis makes diagnosis more difficult, and other diseases such as tumors and deformities must be excluded. Therefore, detailed examination and analysis must be performed before surgery, and various auxiliary examinations, such as myelography, lumbar anterior epidural, and discography, have certain value for diagnosis and localization. The clinical application of CT scan, CTM and MRI in modern times has greatly improved the accuracy of diagnosis. However, all these tests can still produce false positives or false negatives, so they must not rely on instrumental examinations and ignore clinical examinations, let alone be used as a routine application.

This disease can be treated non-surgically in the early stage, and only some patients need surgery. The purpose of the operation is to remove the protruding nucleus pulposus and the free fibrous ring tissue to relieve the compression of the nerve root. This operation is not a major operation, but requires meticulousness and skill, and the operation results are satisfactory. For those cases whose diagnosis has not been confirmed, non-surgical treatment should be performed first, and repeated inspections should be performed at the same time to further confirm the diagnosis, and exploration should not be used as a means of confirmation.

The satisfactory results of lumbar disc herniation can reach 78% ~ 92%. Poor results are reported in 4.6% to 8%, and most of these patients require reoperation. The reasons are mostly due to: incorrect diagnosis; incorrect positioning and unresection of the disc; improper selection of indications; unskilled technique or rough operation causing complications such as bleeding, nerve root adhesion or injury; incomplete surgery; Postoperative infection; sacral nerve root compression time is too long. Therefore, affirmative diagnosis, strict indications, timely surgery, meticulous operation and prevention of complications are the fundamental measures to improve the efficacy of surgery.

1. The diagnosis of lumbar disc herniation is clear, the nerve root compression is more severe, and it is not effective after non-surgical treatment, or the authors should be treated repeatedly.

2. The central type of intervertebral disc is protruded, which causes sensation and muscle weakness in both lower limbs and perineum, and those who have difficulty in urinating and defecation should be treated early or urgently.

1. Preoperative positioning is the most important. In general, based on detailed examinations (including sensory disturbances, weakened muscles, abnormal reflexes, waist tenderness, etc.), you can determine which disc is protruding and the nerve root is compressed. See Table 1:

However, disc herniation may differ in symptoms and signs depending on the location or pathology. The protruding part can be a central type, a central side type, an outer type, and an extremely outer type. Prominent pathology can be bulging, protruding, prolapse, and free. Free type can exist in various parts of the spinal canal and even protrude into the dural sac. It is not uncommon for intervertebral disc herniation to occur on the same side or bilaterally. There are also a few that protrude together with the ring ridges. Sometimes the above can also be combined to complicate clinical symptoms and signs, which need to be analyzed and judged carefully. Necessary auxiliary examinations can be made to make correct preoperative diagnosis and positioning.

2. X-rays should be taken routinely before surgery, except for diseases of the lumbar, sacroiliac and sacroiliac joints (such as vertebral tuberculosis, tumors, etc.) to avoid misdiagnosis. According to the changes in the physiological curvature of the lumbar spine, the prominent intervertebral space is mostly narrow, and the vertebral body can be seen with labial process hyperplasia, which can help diagnosis. In addition, the X-ray film can also show congenital variation, the number of lumbar vertebrae and the height of the sacral condyle plane can be used as a basis for positioning during surgery. In cases of suspected spinal stenosis, CT examination should be performed.

3. The patient needs to stay in bed for about 2 to 4 weeks after surgery. Before surgery, the patient should pay attention to and instruct the patient to practice bed movement and urination to reduce the difficulty of defecation after surgery.

4. In general, there is very little bleeding during the operation, and no blood matching is needed, but the weak ones should be matched with blood.

1. Posture For cases with unilateral protrusion, the lateral position should be adopted so that the laminar space can be satisfactorily deployed to facilitate surgery; the abdomen will not be compressed to prevent the epidural venous plexus from congestion, which can reduce intraoperative bleeding. When lying on the side, the diseased side is up, and the spine, hip and knee flexed position is maintained to expand the laminar space. In order to fully expand the laminar space on the disease side, a soft pillow can be placed on the waist or the lumbar bridge of the operating table can be shaken up.

For bilateral disc herniation, central protrusion and combined spinal and root canal stenosis, the prone position should be used for bilateral exploration and resection. When prone, use long round soft pillows to raise both sides of the torso to avoid abdominal pressure. The two ends of the operating table are shaken down, so that the lumbar spine is in the anterior flexion position and the laminar space is expanded.

2. Make an incision from the midline of the 4th lumbar spinous process to the 1st iliac spinous process. First, cut the deep fascia close to the margin of the spinous process on the diseased side, and peel the sacrospinalis muscle under the periosteum to see the spine exposure. Lateral dissection should reach the posterior joint once to avoid further dissection and hemostasis and prolong the operation time. With the laminar automatic pull hook to open the incision, the diseased lamina and the ligamentum flavum can be clearly exposed. If both sides of the lamina are to be exposed, the opposite side can be exposed in the same way. Generally, simply exposing one side only needs to expose one side of the lamina.

3. After the correct positioning of the enlarged laminar space, the laminar space of the lumbar 5 to 1 is large, and most of them do not need to be enlarged; When expanding, the lower edge of the previous lamina can be bitten with a rongeur to expand to the required range. Generally, it can accommodate the end of the little finger. Bone surface bleeding with bone wax to stop bleeding.

4. Remove the ligamentum flavum. In the enlarged laminar space, use the tip of a sharp-edged knife to close the lower edge of the ligament next to the spinous process, and cut the lower edge of the ligamentum flavum. The ligamentum flavum was removed in one piece up and out. During operation, the tip of the knife should be kept in the field of vision, not to exceed the inner surface of the ligamentum flavum, and the cutting edge should always be upward, and carefully cut to avoid damaging the dura mater and nerve root in front of the ligamentum flavum. The ligamentum flavum, often in the intervertebral disc herniation space, is thick and brittle, and tends to tear when stretched. Care should be taken. The remaining ligamentum flavum can be removed with nucleus pulposus.

5. Exploring and exposing the disc herniation of the ligamentum flavum can reveal the dura mater and its outer nerve roots. The dura mater and epidural fat were separated with a dural stripper, the nerve root was found, and the nerve hook was gently pulled apart, and the inside and outside were directly inspected. The protrusions are mostly tense spherical bulges, and there are also ruptured, damaged fibrous ring tissues can be freed near or far away from the nerve roots in the spinal canal. For long-term disease, there are different degrees of adhesion around the nerve root and the nearby dura mater, which should be carefully separated to avoid damage to the nerve root and dura mater. A few cases stand out and don't miss them. After finding the nucleus pulposus, the nerve root pull should be used instead. The nerve root hook should be arc-shaped, not easy to damage the nerve, and it will not affect the surgical field when removing the protruding disc.

When exposed, if the expansion of the perceptual gap is insufficient, which affects the operation, the scope of laminectomy should be appropriately enlarged. When using a laminar bone bite forceps to bite the bone, the epidural adhesion should be separated with a dura stripper, and then a small piece of bite bone forceps should be inserted close to the front of the lamina to avoid injury to the spinal cord and nerve root. And bone debris should be removed at any time, not to be left in the spinal canal.

6. Remove the nucleus pulposus and the free fibrous ring tissue. According to the protruding part, pull the nerve root to the inside or outside to reveal the protruding intervertebral disc. If the protrusion is high, the nerve root should not be pulled apart. Part of the protruding intervertebral disc should be removed first, and then the nerve root will be relaxed before it is pulled away, so as not to cause nerve root damage. Properly protect and open the nerve roots and dura mater. After showing all the spherical protrusions clearly, use a sharp-edged knife + shape to cut the protrusions. Use a small but stable pull-saw action when incisions should be made to avoid injuring important surrounding tissues and try to avoid dilated veins. If it cannot be avoided, it should be treated with bipolar coagulation. The disc with high tension protrudes. After incision, the nucleus pulposus and the damaged fibrous ring burst out. The nucleus pulposus forceps and a small curette can be used to extend into the intervertebral disc to remove the free fibrous ring tissue. . However, care must be taken not to extend too deep and bite off too many fibrous rings, so as not to break through the disc and damage the abdominal aorta and inferior vena cava in front of the vertebra. Clearance should be made within the sagittal diameter of the space shown on the radiograph. If there is a lip-like hyperplasia at the posterior edge of the vertebral body, it should be carefully removed. Explore the lateral crypt without stenosis, completely remove the lateral ligamentum flavum, and check that the nerve root canal is unobstructed, and that the lateral movement of the nerve root can reach 1 cm is considered complete surgery.

During the surgery, bone or fibrous ring fragments should be removed at any time to avoid being pushed and left around the dura mater and nerve root, which will affect the efficacy in the future. Sometimes bleeding may inevitably occur, mostly due to damage to the small veins before the dura mater. You can use a small cotton pad with a black thread to gently block the hemostasis. The operation can still be performed as usual. When the disc is removed, you can remove the cotton pad And most no longer bleed.

7. Hemostasis, suture and hemostasis must be thorough, including bleeding in the spinal canal and muscles, so as to avoid hematomas and adhesions that cause postoperative pain. In the process of hemostasis, spinal anesthesia should be withdrawn to relieve the pressure on the large veins in the abdominal cavity in order to stop bleeding. Take out all the blocked cotton pieces, and cover them with a free thin layer of fat film (taken from the skin) outside the spinal cord. After the tube is drained under negative pressure, the wound is washed and sutured layer by layer.

The satisfactory results of lumbar disc herniation can reach 78% ~ 92%. Reports of poor results range from 4.6% to 8%.

1. Intraoperative positioning is very important. The following methods can be used: the plane of the iliac crest is equivalent to the lumbar spinous process; Examination; The spinous process of the sacral vertebrae is small and continuous, and the lamina has ridges without gaps, which is very obvious compared with the larger laminar space of the lumbar 5 1; Location also helps in positioning. However, there are many congenital variations in the lumbar region, which should be carefully compared with preoperative X-ray films; special attention should be paid to lumbar vertebralization and sacroiliac vertebralization to avoid positioning errors.

2. Hemi-lambular plate shows little damage and saves time. The spinous process and the superior and interspinous ligaments remain intact, and the postoperative recovery is fast. It should be used in case of unilateral lesions. But the size of the exposure should be subject to the needs of surgery, and if necessary, bilateral exposure is still required. The scope of laminectomy is also based on this principle. It is necessary to ensure that there is sufficient surgical field when removing discs, and nerve roots and dura mates can be properly protected. But it is better not to damage the posterior joint, and those who must be removed should perform fusion at the same time, so as not to affect the stability of the lumbar spine and severe back pain.

3.90% of lumbar disc herniations occur in the lumbar discs between 4 to 5 or 5 to 1 in the lumbar disc, but there are cases where both protrude at the same time. Clinical manifestations, multiple disc herniation is one of the reasons for reoperation. Therefore, if there is no CT symptom, when there are two signs of compressed nerve roots, it is advisable to explore the two gaps at the same time, especially if no disc herniation is found before the operation, the other disc should be explored to avoid omission.

4. During the operation, sometimes the intervertebral disc is bulged, and it is difficult to determine whether to remove it; sometimes the protrusion may be temporarily retracted in the supine position and under anesthesia, and the operator should distinguish and judge. The identification method is: the surface of normal discs is smooth, bright, and has a sense of elastic tension when touched; pathological discs have a rough surface, loss of gloss, poor elasticity, softness when touched, adhesions around nerve roots, and venous congestion. Such as normal saline inside the nucleus pulposus, the normal tension is very large, only a small amount can be injected; pathological people with less tension, easier to inject, up to 1 ~ 2ml. Pathological cases should be removed.

5. Nerve root injuries are mostly caused by rough pulling or being squeezed by instruments when the disc is removed. Rupture of the dura mater is often caused by accidental injuries when removing the ligamentum flavum and the lamina. If the dura mater is torn, and there is cerebrospinal fluid overflow, do not directly attract, but pad with a cotton pad to avoid damage to the pony tail, and should be carefully sutured to repair the cleft.

1. It is recommended to lie supine for several hours after operation. A thin pillow should be placed on the waist to adapt to its lordosis to achieve effective compression and hemostasis; and pay attention to the smooth flow of negative pressure drainage. You can then turn around casually.

2. Difficulty urinating. Patients should be encouraged to urinate automatically; urinary catheterization should be done only as a last resort.

3. Getting up too early after surgery can cause symptoms to recur. Postoperative rest should be in bed for 2 to 4 weeks to facilitate local healing. Perform post-operative back muscle exercises to prepare for getting up.

4. Discharge patients should be instructed to exercise their back muscles frequently. Pulling heavy objects is applied properly and is best avoided. Normally, light work can be resumed within 1 month, and original work can be resumed after 3 months, but heavy physical work should be avoided.

Table 1 Signs of lumbar disc herniation

Protruding disc	Compressed nerve root	Sensory disorders	Muscle weakness	Reflection anomaly
Waist 3 4	Waist 4	Calf anterior medial	Knee extension	Knee tendon
Waist 4 5	Waist 5	Outside of calf, inside of instep	Toe and foot back extension	Knee or Achilles tendon
Waist 5 1	1	Back of calf, outside of dorsal foot	Plantar flexion of toes and feet	Achilles tendon