Category: <span>Conditions and Treatments</span>

Sciatica

Sciatica is a general term that refers to pain in the leg. Numbness, weakness or tingling may occur with pain. The sciatic nerve runs down the back of the thigh and it has as components several nerves from the spine. Consequently, sciatica can be pressure on a nerve in the spine (common) or less, commonly, injury to or compression of the sciatic nerve.

Causes, incidence, and risk factors

Common causes of sciatica include:

• Herniated lumbar disca with pressure on a spinal nerve
• 
• 
• Degenerative disc disease which causes pressure on spinal nerves
• Spinal stenosis
• Pelvic injury or fracture
• Rarely, tumors

Symptoms

The symptoms of sciatica can vary but typically pain from the buttock down the posterior thigh occurs which can travel to the calf. Numbness, tingling or weakness may accompany it. It may vary with position, time of day, with activity or posture. Back pain may be associated with it.

Signs and tests

Physical examination may reveal numbness or weakness when assessed by a spinal physician. There may be reflex changes and pain on lifting the leg (the so-called “positive straight leg raise’)
Follow up studies such as xrays, MR scans and nerve studies may be ordered.

Treatment

Sciatica is not a disease, it is a symptoms. Therefore treatment of the underlying condition, such as spinal stenosis or acute disc herniation may address the sciatica.  Typically this involves conservative therapy such rest, NSAIDs, and physical therapy.  See Good Back Care for more information.

Surgery is occasionally done:

see lumbar microdiscectomy or lumbar laminectomy

Expectations (prognosis)

Depending on the cause and duration of symptoms the prognosis is varied, but most patients can get good relief.

Calling your health care provider

Call your doctor right away if you have:

• Unexplained fever with back pain
• Back pain after a severe blow or fall
• Redness or swelling on the back or spine
• Pain traveling down your legs below the knee
• Weakness or numbness in your buttocks, thigh, leg, or pelvis
• Burning with urination or blood in your urine
• Pain that is worse when you lie down, or awakens you at night
• Severe pain and you cannot get comfortable
• Loss of control of urine or stool (incontinence)

Also call if:

1. You have been losing weight unintentionally
2. You use steroids or intravenous drugs
3. You have had back pain before but this episode is different and feels worse
4. This episode of back pain has lasted longer than 4 weeks

If any of these symptoms are present, your doctor will carefully check for any sign of infection (such as meningitis, abscess, or urinary tract infection), ruptured disk, spinal stenosis, hernia, cancer, kidney stone, twisted testicle, or other serious problem.

Prevention

Prevention varies depending on the cause of the nerve damage. Avoid prolonged sitting or lying with pressure on the buttocks. Good Back Care is essential.

Minimally Invasive Spine

Surgery is the use of small incisions, meticulous tissue handling and the latest microscopic technologies to do operations that in the past would have required large incisions and extended recoveries.

This technology can be applied to:

1. Lumbar decompressions
2. Anterior cervical fusions
3. Posterior cervical foraminotomies
4. Some lumbar fusions

To illustrate a case in point the following was described on the SpineUniverse website:

SpineUniverse Case Report: Minimal Access Spinal Technologies (MAST) Fusion for Osteomyelitis

HISTORY

This 84 year old man was initially reviewed in September 2001 after having had a laminectomy performed by an outside institution for presumed spinal stenosis. He had had a poor outcome from the surgery in terms of hip and thigh pain and postoperative MR scanning at that time confirmed multiple lesions throughout the lumbosacral spine, which on CT-guided biopsy confirmed underlying metastatic prostate cancer. He was managed non-surgically with appropriate chemotherapy and radiotherapy.

This man presented in April 2003 with severe mechanical back pain, in the absence of neurological symptoms in his lower limbs and without bladder or bowel dysfunction. On examination he was noted to be somewhat cachetic, neurologically intact, with an elevated white cell count and ESR. His initial imaging is shown below:

(Above): Marked osteopenia is present. The L2/3 disc space is ill-defined and there appears to be a crush fracture in the L3 vertebral body.

(Above): T1-weighted sagittal MR scanning showing low signal change in the L3 body and lower portion of the L2 vertebral body. The L2/3 disc space is poorly defined. No epidural collection was identified on the imaging

Initially it was felt that the changes in the L3 body were due to metastatic prostate cancer. Because of the peridiscal changes however, a CT-guided aspiration biopsy of the disc space was effected and tissue taken for culture. Enterococcus was cultured from the disc space and appropriate antibiotic therapy was commenced. A preoperative DEXA scan gave a lumbar T score of -3.4.

After 2 weeks of antibiotic therapy, repeat MR scanning was unchanged and the patient still suffered from severe mechanical back pain resistant to bracing and relieve with bed rest. He again had no neurological symptoms in his lower limbs and was neurologically intact. It was felt that the loss of the posterior columns from his initial surgery had left him with a grossly unstable spine that may fuse over time with the smouldering disctis/osteomyelitis, however until that occurred he was at major risk of developing kyphosis, collapse and neurological compromise. Assessment by our medical and anaesthetic services deemed him unfit for a major reconstructive procedure to perform either an anterior or posterior vertebrectomy. In view of this, a minimally invasive procedure was offered in hopes of maintaining a posterior tension band whilst fusion of the anterior column occurred.

OPERATIVE DETAILS

The patient was brought to the operating room and general anaesthesia was administered. After administration of intravenous antibiotic, the patient was placed into the prone position on the Jackson operating table. A digital fluoroscope was draped into the surgical field. A 2 cm incision was then made over the pedicle of L4 on the right. Using both AP and lateral films, the left L4 pedicle was then cannulated using and 11G bone biopsy needle (see below):

Under fluoroscopic guidance, guide wires were then placed into both the L2 and L4 vertebral bodies:

The L4 pedicle was then tapped and a 7.5 mm x 45 mm Sextant® (Medtronic-Sofamor Danek, Memphis, TN) screw was then placed. A 6.5 mm x 50 mm screw was then placed in the L2 pedicle (see below):

A rod was then passed through the heads of both screw using the Sextant® apparatus (see below):

The heads were secured and a similar procedure was performed on the left. The final construct is shown below:

The entire procedure was performed through 6 incisions 2 cm in length each (see below):

There were no problems intraoperatively and no appreciable blood loss. The patient was transferred to the ward uneventfully. Total operating time was 70 minutes.

POSTOPERATIVE COURSE

The patient was well postoperatively and mobilized 48 hours after surgery in a brace. His mechanical pain had improved dramatically. His upright x-rays and CT scans at L2 and L4 are shown below and showed no adverse features:

He was discharged on oral antibiotics 2 weeks later. At last follow-up, 4 weeks after surgery, he remained pain free with no evidence of kyphosis on imaging.

DISCUSSION

Discitis and osteomyelitis leads to loss of structural strength of the vertebral body. With the loss of posterior elements from previous surgery gross instability can result. In patients who would not tolerate major spinal reconstruction, prolonged bedrest may be associated with significant morbidity and potential mortality. In this sort of scenario, being able to provide structural stability through a posterior tension band can lead to eventual fusion across the involved segments. This approach has been described before in the face of osteomyelitis, where pedicle screw fusion alone has lead to stability and eventual fusion.1 The application of minimally-invasive technology to this however is a new approach. By using MAST® techniques and the Sextant® apparatus, stabilization for osteomyelitis was effected in a patient who otherwise may not have been fit for any surgical endeavour.

The use of minimally-invasive approaches to spinal instrumentation is an exciting new technology that will allow surgery to be performed in patients who previously unfit for surgical intervention. Aside from degenerative disease, this case illustrates a novel approach to the stabilisation of the spine in the face of serious infection in a patient unfit for a major intervention.

REFERENCES

1. Karlsson MK, Hasserius R, Olerud C, Ohlin A: Posterior transpedicular stabilisation of the infected spine. Arch Orthop Trauma Surg 2002 Dec;122(9-10):522-57
2. Case 2- Lumbar Endoscopy

History

This 55 year old man was referred to the surgeons at Dalcross Private Hospital and after having had 3 previous lumbar operations. The initial operation had been performed elsewhere for lumbar disc disease, at which time he suffered an inadvertent dural breach. Postoperatively, she developed a lumbar pseudomeningocoele and had 2 attempts elsewhere to try and close the leak. Their was currently no leakage of CSF from the wound. Unfortunately, he continued to have symptoms, and had postural symptoms of worsening back pain and pressure in the standing posture, relieved by lying down. His most recent preoperative MRI scan on referral is shown below (figure 2.1-2.2):

The MRI suggested a multiloculated CSF collection in the subfascial region of the lumbar wound. In view of the fact that he had had 2 previous attempts to repair the pseudomeningocoele, it was felt that a further open procedure would not be of great benefit. Symptomatically, the patient had a one-way valve effect with fluid draining from his thecal sac into his pseudomeningocoele, that was thought to be giving him the majority of his symptoms.

Technique

The patient was brought to the operating room and general anaesthesia was obtained. He was place in a prone position on the Andrews operating table. A rigid 6 mm 30( endoscope was then navigated into the pseudomeningocoele through a 1 cm paramedian lumbar incision. The pinhole connection between the dura and surrounding tissues was identified and this was enlarged with forceps and a 4F 5 ml Fogarty balloon (see figures 2.3-2.4 below).

Figure 2.3 and 2.4 (below): The 1 mm connection between the pseudomeningocoele and the thecal sac is identified. A magnified view is shown to the right. Neural structures are visible inside the dura.

Figure 2.5 (above): Post-fenestration myelogram confirming good retrograde flow of contrast material.

The procedure was uncomplicated and an on-table myelogram confirmed good retrograde flow between the pseudomeningocoele and the thecal sac (see figure 2.5).

Postoperatively, the patients recovery was unremarkable and he was well at last followup from her preoperative symptoms.

Comment

Cerebrospinal fluid leakage can complicated up to 10% of spinal surgical cases. Typically these are primary repaired and require no further intervention. Rarely, the leaks persist and patients may present with persistent CSF leakage from the wound, a subcutaneous swelling or a contained but symptomatic swelling. The initial treatment in typically aspiration and lumbar drainage or re-exploration. An epidural blood patch may also help. Occasionally this is unsuccessful. In the case, with 2 previous re-explorations, it was felt a minimally invasive procedure would avoid the pain and risks of another open procedure. Coupled with this, the internal architecture of the pseudomeningocoele was not disturbed, which allowed for easier identification of the flap valve.

Case 3: SpineUniverse Case Report: Minimal Access Spinal Technologies (MAST) Fusion for Trauma

HISTORY

This 86 year old man was admitted with a history of a fall in the absence of neurological deficit. He had significant comorbidities in terms of cardiac and respiratory disease. His initial imaging is shown below:

(Above): Preoperative T2-weighted MRI scan showing edema in the T12 vertebra is consistent with a recent fracture.

(Above): Sagittally reconstructed CT scans showing axial fractures in the T12 vertebrae extending through all 3 columns. The injury was consistent with a T12 undisplaced Chance fracture.

INTERVENTION

Because of his general health, the patient was not deemed fit for a major reconstructive procedure. Prolonged bedrest was also preferably avoided. In view of this he was offered percutaneous pedicle screw fusion via the MAST (Minimal Access Spinal Technology) technique using the Sextant® apparatus (Medtronic-Sofamor Danek, Memphis, TN).

The patient is shown below positioned in preparation for the surgery:

Using the sextant apparatus the T11 and then the L1 pedicles were sequentially cannulated with 5.5 x 45 mm screws. 4 screws were placed with 2 rods. The procedure was performed through a total of six 2 cm incisions. The Intraoperative imaging is shown below:

The incisions at the end of the case are shown as below:

There were no problems intraoperatively and no appreciable blood loss. The patient was transferred to the ward uneventfully. Total operating time was 75 minutes.

The patient was mobilized in TLSO with no adverse surgical complications.

4 weeks after surgery he was transferred to the rehabilitation service with no complications as a result of the stabilization. It would be envisioned that the instrumentation would be removed 12 months after surgery.

DISCUSSION

This case demonstrates the application of minimally-invasive spinal fusion technology to spinal trauma for the stabilization of a fracture that otherwise would have required a more extensive operation in a patient with significant comorbidities or for whom otherwise prolonged best and immobilization were the only options, with the risks of the known complications of these actions present as a result.

Chance fractures are classically described as occurring after motor vehicle accidents with seatbelt injuries. The fractures, if through the bony elements, if undisplaced, may be managed in a brace, but most surgeons would suggest some form of short segment fixation with early mobilization.(1,2)

This report described the application of MAST technology to facilitate spinal fusion for spinal trauma. In under 90 minutes, stabilization of an unstable fracture in a medically unwell patient was achieved. The use of this minimally-invasive technique offers home for the management of fractures in elderly patients as well as allowing for minimal blood loss and operative morbidity. Clearly, not all fractures are suitably managed through this technique but for those deemed medically inoperable or needed simple stabilization MAST fusion offers home of rapid mobilization with minimal risk.

REFERENCES

1. Louis CA, Gauthier VY, Louis RP: Posterior approach with Louis plates for fractures of the thoracolumbar and lumbar spine with and without neurologic deficits. Spine 23: 2030-2039, 1998
2. Parker JW, Lane J, Karaikovic EE, et al: Successful short-segment instrumentation and fusion for thoracolumbar spine fractures. A Consecutive 4 ½ year series. Spine 25: 1157-1169, 2000

Dynamic stabilization is an exciting part of spine surgery which is somewhere between a fusion and a decompression. Some refer to it as a “soft stabilization”. The most widely used dynamic stabilization device is the X’Stop device shown in the figure above and below:

The device acts as a buffer and is placed between the spinous processes of affected levels. It has 2 effects:

1. It opens up the space for the nerves
2. It reduces motion slightly by limiting flexion

Below is a the anatomy of a patient who gets leg symptoms when they stand but no symptoms when sitting:

This patient has pinching of the nerves due to disc bulging and facet and ligament enlargement.

An X’Stop device is placed between the spinous processes in the operating room:

This is the appearance after placement where there is more room for the nerves:

Aside from pinched nerves, the X’Stop device is also being used above fusions to try and buffer normal levels and hopefully stop them wearing out prematurely. Below are xrays of a patient with a fusion with an X’Stop at the level above:

At the moment this technology is new and still being evaluated. There are a multitude of dynamic stabilization devices appearing, some good, some not so good.  Not all patients are suitable for this surgery but for those that are suitable relief whilst keeping motion may occur.

For a Video on the first X’Stop case in the Reno/Northern Nevada area click here.

What is a Disc?

The spine is a column that is made of up bones, discs and ligaments. The blocks of bone (or vertebrae) provide the anterior support and structure of the spine. The discs are in between the bones and act like a “shock absorber” between the vertebrae. The discs also contribute to the flexibility and mobility of the spinal column. The discs are made up of two parts:

1. the inner portion of the disc is a jelly-like material and is called the nucleus pulposus and
2. the outer part, called the annulus fibrosis of the disc, is stronger and more fibrous. The annulus fibrosis surrounds and supports the inner jelly material. The annulus is rich in nerve fibers, especially the back portion, and may play a role in the production of discogenic back pain.

Disc material is mainly composed of water and other proteins. As a normal part of aging, the water content gradually reduces. This can cause the disc to flatten out and even develop tears or cracks throughout the annulus fibrosis. These discs are often referred to as “degenerative” discs and may or may not cause pain.

In the case of a degenerative disc, the inner jelly material (the nucleus pulposus) can bulge out and press up against the annulus fibrosis. This can stimulate the pain receptors causing pain to occur. The cracks or tears that develop within the annulus fibrosis can also become a source of pain. Finally, the inner nucleus can also come out through the cracks in the annulus and compress nerves or spinal cord, a condition that may cause weakness, pain, pins and needles or numbness, and may require surgery.

Current Treatment Options for Lumbar Disc Disease  

Non-surgical options for people with disc protrusions in the lower back include rest, heat, pain medications and physiotherapy. When non-surgical treatment options fail, surgery is often the next step. This usually means spinal fusion surgery. Back pain with compression of the nerves in the neck or spinal cord is a common condition that affects the spine and may require surgery. If only nerves are compressed, with symptoms in one or both legs, a period of conservative management is instituted and if this fails surgery is contemplated. Typical surgical procedures for ongoing leg symptoms include lumbar microdiscectomy of lumbar laminectomy. These operations do not address back pain. Occasionally, a spinal fusion is performed for back pain or for back pain in association with leg symptoms. All these procedures are performed from a posterior approach which involves a degree of muscle stripping in order to expose the bony structures.

Spinal fusion is typically performed from a posterior approach in the lumbar spine, using screws, rods, cages and bone graft from the hips. there is an extensive recovery period and the back becomes stiffer. If a fusion is required or if a large component of the pain is back pain, then a posterior approach is necessary. Occasionally, for pure back pain, thought to be coming from the discs, an anterior fusion is performed, with or without a posterior fusion.

(Above): Typical lumbar fusion with screws, cages, rods and bone graft performed for lumbar disc disease:

The main problems with fusing bones in the lower back  are that adjacent levels in the lumbar spine are placed under more strain. This is particular common with posterior lumbar fusions and less so anterior ones. This has increased “wear and tear” at the surrounding disc space levels has been termed “adjacent segment disease”. We now know that if 10 people have a single level fusion, at 10 years 2 have had to have another operation for narrowing at the next level either above or below. Secondly, the bone does not always heal or “fuse” correctly. In fact, the overall success rates for these procedures range from 40% to 90%. Movement is also lost, with a loss of movement at one or more levels.

(Above): Wear and tear above a previous fusion  (arrows)

Lumbar Disc Replacement Instead of Lumbar Fusion

A new technique which has been available in Europe for the past 11 years is removing the disc and then replacing it with an artificial disc. This has 2 main benefits:

1. Motion is maintained and the patient will not feel a restriction in the range of motion.
2. Theoretically adjacent segment disease will not occur.

Consequently, patients undergoing placement of an artificial lumbar disc may need less surgeries on their back in the future.

The idea of spinal disc replacement is not new. It was first attempted 40 years ago when implanted stainless steel balls were implanted into the disc spaces of over 100 patients. These pioneering efforts were followed by more than a decade of research on the degenerative processes of the spine, spinal biomechanics and biomaterials before serious efforts to produce an artificial disc resumed. There are currently a number of artificial disc prosthesis available on the market:

Prodisc® Disc Prosthesis

Charite® Disc Prosthesis

Maverick® Disc Prosthesis

Others

Both the Prodisc and the Charite have the longest track record in terms being used in patients, with the Prodisc having been used clinically for 11 years, far longer than the scenario in the cervical spine.

Indications

Not all patients with back pain are suited to placement of an artificial lumbar disc prosthesis. The ideal candidate has the following features:

1. Back pain thought to be coming from the discs, not the facet joints.
2. No previous surgeries other than a lumbar microdiscetomy
3. Not markedly overweight
4. Relatively few if any abdominal operations
5. Little in the way of leg symptoms

Part of the workup for potential artificial disc placement includes plain x-rays, MR scanning, facet blocks and a lumbar discogram. The latter study involves injecting the suspect lumbar discs with saline to see if the exact same pain is reproduced that is concerning the patient. Adjacent discs are also injected and used as controls. The procedure is painful but absolutely necessary and is performed by a skilled neuroradiologist in a CT scanner. Occasionally an abdominal angiogram is also required.

Technique of Artificial Lumbar Disc Placement

The surgery takes 2-3 hours and is performed through a 10 cm incision in the abdomen. The main risks of the procedure are that the large veins and arteries from/to the legs need to be dissected away from the front of the disk. There is a risk of injuring these vessels with major bleeding requiring transfusion or possibly even death. The risk of a disaster happening is 1-3%. Occasionally more than 1 level is operated upon in which case the risks get higher. Men have a risk of developing retrograde ejaculation after surgery, which may render them infertile. It is a good idea for men planning on families in the future to donate sperm preoperatively. The other risks including infection, abdominal problems etc etc gives a 5% overall risk of something bad happening. Typically, if the disc is abnormal on MR with a positive provocative discogram, the success in terms of pain relief is about 70%.

The Prodisc® consists of 2 outer metal parts with an inner polyethylene core that makes it a ball and socket joint (see below). Other devices come in one or 3 pieces:

Initially the disc space to be operated upon is identified and removed:

Note that the nerves themselves are not decompressed.

The individual components of the Prodisc® are then inserted in sequence to replace the original disc. Some devices are assembled in situ (Charite):

The final result is removal of the disc, with (hopefully) removal of the pain generators at the back of the disc, and placement of a prosthesis that will allow movement in all normal planes:

FLEXION/EXTENSION                                                                                LATERAL BENDING

Results of Artificial Lumbar Disc Placement

In the best cases, 70-90% of patients will get relief of the back pain

The operation is not for leg pain

The risk of complications is about 5%. There is a very small of chance of something happening like dying. There is a higher chance, however of needing revision surgery than an anterior fusion and at the moment we do not know what long term benefits this operation conveys over an anterior fusion.

Risks and Complications

Death or major nerve/blood vessel injury/massive transfusion 1-2%

All other complications including bleeding, infection, abdominal complications, blood clots etc etc 5%

Retrograde ejaculation (impotence) in men 5-10%

Recovery

Hospitalization is typically for 2-5 days

A brace must be worn for 3 months

Extension of the back must be avoided

Swimming can be commenced after 4 weeks

No sporting activities, golf or tennis to be undertaken for 3 months

Running after 6 weeks

X-rays will be done immediately after surgery, at 6 weeks, 3 months, 6 months then yearly to ensure the prosthesis is not moving (see below). A survey form is also completed

Non-Surgical Options

Despite the length discussion about surgery, most patients get better without surgery.

Conservative therapy comprises

• Analgesia with NSAIDs (e.g. Mobic, Voltaren or Celebrex)
• Analgesia with other medications such as Tramadol
• Avoidance of bending/lifting/twisting/sitting for prolonged periods
• Physiotherapy
• Hydrotherapy
• Perineural/intrafacet steroid and local anesthetic injections
• Possibly acupuncture
• Seeing a Pain Management Centre about spinal stimulators, pumps and pain management programs

Your surgeon and primary care doctor can tailor a conservative management plan with some or all of the following, and for the vast number of sufferers, conservative management works. There are other alternative therapies available, but many have shaky scientific foundations and consequently are best avoided. Spinal manipulation is best avoided as it can entice more disc material to prolapse.

IMPORTANT POINTS

• The selection of patients for this surgery is very particular and left to very specialized neurosurgical and orthopedic spinal surgeons
• We do not yet know the long term outcomes of having an artificial disc for 50+ years
• Over 2000 Prodiscs® have been placed in patients in Europe over the past 12 years and none have been removed. Over 10000 Charite® devices have been placed over the past 20 years. Other devices have only been used for 2-5 years.
• The aim is to keep movement at the level of surgery so that extra stress is not placed at the adjacent level.
• The operation is good for back pain (70% likely to improve) but will not change leg symptoms.
• The risk of something disastrous happening from the surgery such as death, massive bleeding or sever nerve injury  is 1-2%. The risk of other complications is about 5-10% which included the risks of infection, bleeding etc. etc. There is a 10% in males of developing retrograde ejaculation which would render the patient infertile. Sperm donation prior to the surgery for patients contemplating surgery is a good idea if they are still planning on having a family. a
• The long term results with artificial discs are not yet known. In the lab, the discs have been tested to an equivalent of 15 years with little wear. We do know that hip and knee replacements do wear out and the same may happen with this prosthesis- at this stage we just don’t know. I suspect not many people will need them revised but it may take 10-20 years to find out. Significantly, very few have been removed to date. I personally would have a prosthesis over a fusion, if indicated, despite the long term uncertainty.
• At this stage it is only very few fusion patients who qualify for this procedure.

What is a Disc?

The spine is a column that is made of up bones, discs and ligaments. The blocks of bone (or vertebrae) provide the anterior support and structure of the spine. The discs are in between the bones and act like a “shock absorber” between the vertebrae. The discs also contribute to the flexibility and mobility of the spinal column. The discs are made up of two parts:

1. the inner portion of the disc is a jelly-like material and is called the nucleus pulposus and
2. the outer part, called the annulus fibrosus of the disc, is stronger and more fibrous. The anulus fibrosus surrounds and supports the inner jelly material.

Disc material is mainly composed of water and other proteins. As a normal part of aging, the water content gradually reduces. This can cause the disc to flatten out and even develop tears or cracks throughout the annulus fibrosus. These discs are often referred to as “degenerative” discs and may or may not cause pain.

In the case of a degenerative disc, the inner jelly material (the nucleus pulposus) can bulge out and press up against the annulus fibrosus. This can stimulate the pain receptors causing pain to occur. The cracks or tears that develop within the annulus fibrosus can also become a source of pain. Finally, the inner nucleus can also come out through the cracks in the annulus and compress nerves or spinal cord, a condition that may cause weakness, pain, pins and needles or numbness, and may require surgery.

Current Treatment Options for Prolapsed Discs  

Non-surgical options for people with disc protrusions in the neck include rest, heat, pain medications and physiotherapy. When non-surgical treatment options fail, surgery is often the next step. This usually means spinal fusion surgery. Neck pain with compression of the nerves in the neck or spinal cord is a common condition that affects the spine and may require surgery. If only nerves are compressed, with symptoms in one arm, a period of conservative management is instituted and if this fails surgery is contemplated. Early surgery is performed if there is severe weakness or pain that cannot be effectively controlled with available analgesia. If the spinal cord is being compressed,  surgery to decompress the spinal cord is usually recommended. This compression can be caused by bulging disc or bony spurs.

Surgery on the spinal cord is performed either from the back of the neck (laminectomy) or through the front of the neck (cervical discectomy or vertebrectomy). If the compression of the spinal cord is from the front, then the decompression must be done from the front (anterior decompression). Typically if the entire disc is removed, a wedge of bone is taken from the hip and put into its place, possibly with a plate and screws to hold it into place (see below). This is commonly referred to as an anterior cervical decompression and fusion.

(Above left): MRI scan of the cervical spine showing a typical disc protrusion between the 5th and 6th cervical vertebra compressing the spinal cord

(Above middle): A Schematic diagram of a typical anterior discectomy and fusion procedure. A block of bone graft is placed into the space left when the disc is removed

(Above right): A postoperative x-ray on the patient shown to the left. The disc has been removed, a block of bone has fused the 5th and 6th vertebrae and a plate with screws holds it into place

This is a common operation and often no bone graft from the hip is taken nowadays. Instead bone from a bone bank (donated cadaver bone called allograft) or plastic cages filled with bone substitutes are used. Whilst it takes pressure off the spinal cord, it necessitates that at least 2 of 7 bones in the neck are fused. This does reduce some of the movement in the neck, but patients typically do not notice it unless several levels are fused. Typically after this surgery, the patients were a neck brace for 6 weeks.

The problem with fusing bones in the neck are that adjacent levels in the neck are placed under more strain. This has increased “wear and tear” at the surrounding disc space levels has been termed “adjacent segment stenosis”. We now know that if 10 people have a single level fusion, at 10 years 3 have had to have another operation for narrowing at the next level either above or below. Secondly, the bone does not always heal or “fuse” correctly. In fact, the overall success rates for these procedures range from 48% to 89%. Finally, spinal fusion at one or more levels increases stress to the rest of the spine. This transferred stress may cause new problems to develop at the other levels, which may lead to additional surgery.

There are clear reasons for not putting in artificial disc and doing a fusion instead.

Click here to download a brochure explaining why.
Cervical Disc Replacement Instead of Cervical Fusion

A new technique which has been available throughout the world since 2001 is removing the disc and then replacing it with an artificial disc. This has 2 main benefits:

1. Motion is maintained and the patient will not feel a restriction in the range of motion.
2. Theoretically adjacent segment disease will not occur.

Consequently, patients undergoing decompression and placement of an artificial cervical disc do not need a brace after surgery and may need less surgeries on their neck in the future.

The idea of spinal disc replacement is not new. It was first attempted 40 years ago when implanted stainless steel balls were implanted into the disc spaces of over 100 patients. These pioneering efforts were followed by more than a decade of research on the degenerative processes of the spine, spinal biomechanics and biomaterials before serious efforts to produce an artificial disc resumed. The Bryan cervical disc prosthesis represents a state of the art disc prosthesis, although several are now available. A newer prosthesis, termed Prestige LP® (see below), is also available, outside the US) working as a ball and socket system. The choice is made by the surgeon and tailored to your spine.  Worldwide there are at least a dozen in place.

Prestige Cervical Disc System
    

The Prestige Disc is the first artificial cervical disc that will be available in the US. The is a ball and trough design and mimics normal cervical motion. It is made of stainless steel so postoperative MR scans have a lot of artifact. It is secured to the bone with screws and is useable for one level disease only. The FDA study comparing Prestige to fusion was favorable for the disc.

Bryan Cervical Disc System

The Bryan Cervical Disc System is a composite type artificial disc designed with a low friction, wear resistant, elastic nucleus with two anatomically shaped metal plates. A flexible membrane forms a sealed space and contains a lubricant to reduce friction and wear and tear. The implant allows for normal range of motion and comes in five sizes. Expect US release in 2008
    

(Above) X-rays of the cervical spine after implantation of an artificial disc. Normal movement is preserved.

The initial clinical experience with the Bryan Total Cervical Disc Prosthesis has been promising.

(Above left): The Bryan artificial disc prosthesis.

(Above right): A skeletal model of the cervical spine showing how the artificial disc is placed.
When Not to Have an Artificial Disc (click here)

Key Points

• The selection of patients for this surgery is very particular and left to very specialized  spinal surgeons
• We do not yet know the long term outcomes of having an artificial disc for 50+ years
• Over 10000 artificial discs have been placed in patients in worldwide over the past 5 years
• Not all patients are suitable for artificial disc surgery

More information:

1. The aim is to keep movement at the level of surgery so that extra stress is not placed at the adjacent level.
2. The operation is best for arm pain (80-90% likely to improve)
3. The risk of something disastrous happening from the surgery such as death or quadriplegia/cord injury is 1-2%. The risk of other complications is about 5-10% which included the risks of swallowing or voice problems, which may or may not be permanent, infection, bleeding etc. etc. These are the same risks as an ACDF but the 20% morbidity from the hip graft, if used, is avoided.
4. All my patients who receive an artificial disc are informed that if, during the surgery, it is not possible to place the artificial disc, then a fusion is done. This happens in less than 5% of cases, but you must be prepared for this.
5. If you underwent surgery,you would need to x-rays of your neck in flexion and extension at 6 weeks, 3 months, 6 months then yearly after surgery. No collar is required postoperatively and you could return to work as soon as 1 week postoperatively.
6. If you have a short neck, it may not be possible to place the prosthesis.
7. The long term results with artificial discs are not yet known. We do know that hip and knee replacements do wear out and the same may happen with this prosthesis- at this stage we just don’t know. It may take 10-20 years to find out. Significantly, very few have been removed to date.

Dr. Sekhon has performed over a thousand anterior cervical fusions. For an appointment call 775-657-8844
BACKGROUND
What is a Disc?

The spine is a column that is made of up bones, discs and ligaments. The blocks of bone (or vertebrae) provide the anterior support and structure of the spine. The discs are in between the bones and act like a “shock absorber” between the vertebrae. The discs also contribute to the flexibility and mobility of the spinal column. The discs are made up of two parts:

1. the inner portion of the disc is a jelly-like material and is called the nucleus pulposus and
2. the outer part, called the annulus fibrosis of the disc, is stronger and more fibrous. The annulus fibrosis surrounds and supports the inner jelly material.

Disc material is mainly composed of water and other proteins. As a normal part of aging, the water content gradually reduces. This can cause the disc to flatten out and even develop tears or cracks throughout the annulus fibrosis. These discs are often referred to as “degenerative” discs and may or may not cause pain.

In the case of a degenerative disc, the inner jelly material (the nucleus pulposus) can bulge out and press up against the annulus fibrosis. This can stimulate the pain receptors causing pain to occur. The cracks or tears that develop within the annulus fibrosis can also become a source of pain. Finally, the inner nucleus can also come out through the cracks in the annulus and compress nerves or spinal cord, a condition that may cause weakness, pain, pins and needles or numbness, and may require surgery.

Current Treatment Options for Prolapsed Discs

Non-surgical options for people with disc protrusions in the neck include rest, heat, pain medications and physiotherapy. When non-surgical treatment options fail, surgery is often the next step. This usually means spinal fusion surgery. Neck pain with compression of the nerves in the neck or spinal cord is a common condition that affects the spine and may require surgery. If only nerves are compressed, with symptoms in one arm, a period of conservative management is instituted and if this fails surgery is contemplated. Early surgery is performed if there is severe weakness or pain that cannot be effectively controlled with available analgesia. If the spinal cord is being compressed,  surgery to decompress the spinal cord is usually recommended. This compression can be caused by bulging disc or bony spurs.

Surgery on the spinal cord is performed either from the back of the neck (laminectomy) or through the front of the neck (cervical discectomy or vertebrectomy). If the compression of the spinal cord is from the front, then the decompression must be done from the front (anterior decompression). Typically if the entire disc is removed, a wedge of bone is taken from the hip and put into its place, possibly with a plate and screws to hold it into place (see below). This is commonly referred to as an anterior cervical decompression and fusion.

Above left): MRI scan of the cervical spine showing a 2 discs pushing on the spinal cord with a smaller disc bulge at the top.

(Above middle): A postoperative xray of a typical anterior discectomy and fusion procedure, in this case performed at 3 levels.
A plastic cage (made of PEEK) is filled with an enhancer of fusion and placed into the disc space. There are markers in front and behind the cage (appear bright white). A Plate holds it all together. Note that the kyphosis (sagging) of the spine is fixed.

(Above right): A postoperative MRI on the patient shown to the left. The discs have been removed, and a complete decompression of the spinal cord has been effected.

This is a common operation and whilst it takes pressure off the spinal cord, it necessitates that at least 2 of 7 bones in the neck are fused. This does reduce some of the movement in the neck, especially, looking upwards at the ceiling and looking over ones shoulder but patients typically do not notice it unless many levels are fused and in most cases, improving neck pain improves neck movement more than the fusion takes away. Typically after this surgery, the patients were a neck brace for 6 weeks.

The problem with fusing bones in the neck are that adjacent levels in the neck are placed under more strain. This has increased “wear and tear” at the surrounding disc space levels has been termed “adjacent segment stenosis”. We now know that if 10 people have a single level fusion, at 10 years 3 have had to have another operation for narrowing at the next level either above or below. This is less likely with multilevel fusions. Secondly, the bone does not always heal or “fuse” correctly. In fact, the overall success rates for these procedures range from 48% to 89%.

Definition

Anterior cervical decompression and fusion is removal of disc and/or bone through an approach through the front of the neck and then filling the cavity formed with bone from the hip and possibly placing screws and plates to hold the whole construct into place. The typical patient presents with either arm symptoms such as pain, weakness, numbness or pins and needles, or else symptoms and signs of spinal cord dysfunction, termed myelopathy. Myelopathy can manifest in a number of ways, including generalized stiffness, difficulty walking, loss of fine motor control in the hands etc etc. Compression of nerves or spinal cord is typically caused by disc material or bony spurs.

A disc protrusion per se may not cause symptoms. If the annulus is acutely torn, neck pain may result, but the management is usually not operative. If the disc pushes on a nerve, as shown in the previous scans, then symptoms down one or occasionally both arms may result. The symptoms can include pain, numbness, “pins and needles”, and weakness.

Anatomy

The anatomy of a typical intervertebral disc as shown below:

(Below): The intervertebral disc lies in front of the spinal nerves and is situated between the vertebral bodies. It carries 80% of the load through that level and is the shock absorber for the spine. The lowermost discs (C56 and C67) are most prone to wear and tear and potential rupture.

Note that there is an outer shell, called the annulus fibrosis and an inner core called the nucleus pulposus. The annulus is the consistency of a pencil eraser, whereas the nucleus is gel-like and, as we get older, dehydrates and becomes like crabmeat. The discs act as shock absorbers and flexing the spine loads the disc. A tear in the outer annulus can consequently cause severe back pain. Patients will often be able to remember a time when they lifted poorly or twisted their back and had severe back pain prior to getting the leg pain. Once an annular tear occurs, it may heal, or it may allow nucleus to come out of the centre of the disc, into the spinal canal, where it may compress nerves. This is usually called one of a number of terms, including “disc prolapse”, “ruptured disc”, “slipped disc”,  “extruded disc” etc etc.  All these terms essentially mean the same thing. Once nerves are compressed, surgery may be complicated. It is important to know that the prolapsed disc cannot be pushed back into place and nothing but time will heal the annular tear. Thus, in general, any surgery is aimed at improving the leg pain, not the back pain.

Reason For Operation

Cervical disc protrusions are not usually operated upon early, but there are some clear situations when a surgeon may recommend early surgery. If there is evidence of severe weakness, early surgery may be offered. If the pain in the arm is so severe that narcotic analgesia is not controlling the pain, early surgery may again be an option. If there is spinal cord compression typically early surgery is also offered.

If a patient has pain, but it is not too severe, then typically conservative management is initiated. It must be remembered that the vast proportion of patients will settle with time and as long as improvements are noted at 6 weeks, there is minimal or no weakness, and the pain is not excruciating and is livable with oral analgesia, then waiting and continuing with conservative therapy is a good option.

If weakness occurs and is not improving, surgery is usually offered. Similarly, if symptoms are not improving at 6 weeks then surgery is an option.

In most cases, when managing arm leg pain, surgery is a treatment option that speeds up the rate of recovery, remembering that most cases will get better by themselves. Again, specific recommendations are tailored to the patient. In the vast number of cases, the goal is control of pain, and an intervention that achieves this and is less invasive than surgery is a reasonable option.

The main reason this form of surgery is performed is to try and reduce the risk of deterioration in spinal cord function. At the extreme end, bad myelopathy patients are wheelchair bound. Coupled with this, even patients with little in the way of symptoms are more at risk of spinal cord injury. This is because the space for the spinal cord is reduced and an accident as trivial as a minor car accident can transiently narrow this space via ligamentous buckling, injuring the cord. Consequently, this surgery is primarily performed as a prophylactic procedure to stop deterioration in the future.

Technique

The operation is preformed under general anesthesia and as shown above a cut is made in front of the neck. The food and wind pipe are shifted over and the operation is performed between these and the blood vessels to the brain. The disc is removed in entirety, and after the spinal cord and nerves have pressure from them removed, graft is placed into the cavity.

This can typically be:

1. bone from the hip (autograft). Painful
2. Bone bank bone (allograft). From cadavers with a small risk of disease transmission
3. A Plastic cage made of PEEK, filled with bone graft substitute or BMP, to enhance fusion (much more common now).
4. A plate and screws may be placed over this to keep the graft in place. The operation takes 1-3 hours and after surgery a collar is in place for 6 weeks.

A cervical plate is shown below:

Risks

The greatest risk is injury to one or more nerves and this is typically 1-2%. There is a risk of death, quadriplegia or severe spinal cord injury. The risks of infection, bleeding etc. etc. are similar to those for a laminectomy as are the risks of general complications. There are other risks particular to this operation. Temporary or permanent swallowing problems or hoarseness of voice can occur. They are common temporarily but not so permanently The hip graft site is more likely to get infected. The combined risks are about 5-10%.

The small but real risks from surgery are the reason why all patients with disc protrusions do not immediately have surgery.

Expectations

In uncomplicated cases the likelihood of good/excellent relief of arm pain is 80-90%. Numbness is slow to recovery and may persist. Weakness also may take 6-12 weeks to return to normal. Pins and needles usually starts to improve immediately.

If the surgery was for myelopathy, as a rule:

• 40% get better
• 40% stay the same
• 20% continue to deteriorate

Recovery

Some pain on swallowing is not uncommon. Some pain at the back of the neck is not uncommon and is due to stretching. Most patients spend 1-2 nights in hospital and mobilize and go home the next day. A collar is worn for 4-6 weeks. At this time repeat x-rays are done, which if satisfactory, lead to discontinuation of the collar.

Non-Surgical Options

Despite the length discussion about surgery, most patients get better without surgery.

Conservative therapy comprises

• Analgesia with NSAIDs (e.g. Mobic, Voltaren or Celebrex)
• Analgesia with other medications such as Tramadol
• Avoidance of neck flexion at computer screens etc. for long periods
• Physiotherapy (traction may help)
• Hydrotherapy (particularly if back pain is a problem)
• Cessation of smoking
• Possibly acupuncture
• Hydrotherapy (particularly if back pain is a problem)
• Perineural steroid and local anesthetic injections

This is not the case for myelopathy secondary to spinal cord compression, in which there are no conservative options except observation (which we try and avoid) or surgery.

Other Points

Anterior cervical surgery is being supplanted in some cases by artificial disc surgery. It still plays a role in trauma, deformity and in the management of older patients with cervical disc disease.

You may read about artificial cervical discs. There are clear reasons for not putting in artificial disc and doing a fusion instead.

Click here to download a brochure explaining why.

Dr. Sekhon has performed over 500 posterior cervical fusions. For an appointment call 775-657-8844

See:

1.  Poster on a series of decompressions
2. Poster on a series of sequential screws
3. Publication on 1026 screws
4. Publication on 50 consecutive decompressions

Definition

A posterior approach to the cervical spine is generally reserved for patients with myelopathy. Myelopathy literally means “sick spinal cord” and can be caused by many things, some of which are not reversible. Compression of the cord can cause myelopathy and is the commonest reason for surgical intervention. The approach is also gaining popularity for the management of trauma and tumor conditions but it is really in the management of myelopathy secondary to degenerative disease (so -called “wear and tear”) that a posterior decompression and fusion is most frequently utilized.

Cervical myelopathy does not typically cause pain. Myelopathy can be asymptomatic or can cause dysfunction in the upper or lower extremities. Typical symptoms include the loss of hand control, a feeling of heaviness in the hands or legs, stiffness in walking and unsteadiness in walking. In the degenerative spine, it is typically caused by pressure on the spinal cord. This can occur because wear and tear leads to bulging of the discs, facet joints become larger and intrude into the space for the spinal cord, and also, some people are borne with a narrow space for their spinal cord.

Anatomy

The spinal cord lives in a bony hole, the spinal canal. A posterior cervical laminectomy involves an incision on the back of the neck and bone is taken away over the spinal cord to its widest diameter. After that, a fusion is performed across the facet joints at these levels using local bone from the laminectomy, screws and plates or rods.

This is the extent of bone removal and decompression from a posterior approach (yellow) allowing for excellent spinal cord decompression. Note that this is greater than that achieved by an anterior approach (orange arrows) where the position of the vertebral arteries limits lateral exposure.

Reason For Operation

The main reason this form of surgery is performed is to try and reduce the risk of deterioration in spinal cord function. At the extreme end, bad myelopathy patients are wheelchair bound. Coupled with this, even patients with little in the way of symptoms are more at risk of spinal cord injury. This is because the space for the spinal cord is reduced and an accident as trivial as a minor car accident can transiently narrow this space via ligamentous buckling, injuring the cord. Consequently, this surgery is primarily performed as a prophylactic procedure to stop deterioration in the future.

The added fusion has several benefits:

• it allows for a much wider decompression
• it prevents the spine falling into kyphosis, which is literally a reversal of the normal curve of the spine, a situation which leaves the spine more prone to injury.

Technique

The procedure is performed under a general anesthetic and is performed on a special table called an Jackson Operating Table which allows safe positioning of the patient as well x-ray to be used throughout the procedure. Typically it takes 2-4 hours.

The head is held in a special device the keep the neck still. This is shown below:

A cut is made in the back of the neck and the thick muscles in the back of the neck are stripped away but reattached again at the end of the operation. The most important part of the case is now removal of the bone and ligaments overlying the spinal cord. This is done very carefully with drills and fine bone-biting instruments.

Once the bone is removed along with the ligaments, screws are placed through plates ( or else connected via titanium rods). X-ray guidance allows for precise screw placement. The screws, rods or plates (so-called “hardware”) holds the bones still whilst the fusion occurs. The bone removed in the laminectomy is crunched up and placed in around the facet joints which have been roughened up and form the bed of the future fusion.

This operation does not typically require a blood transfusion. A typical fusion is shown below.

Risks

The most disastrous complication that can occur from a posterior cervical decompression and fusion is injury to the spinal cord or death. This risk is approximately 1%. Every spinal operation has a risk of leakage of spinal fluid, infection, bleeding, hardware related problems etc. etc. and these would sit at approximately 5%. There are also general risks of clots in the legs or lungs, pneumonia, heart attack etc which is again at about 5%. All in all 90-95% do well from surgery with no complications, but no surgery can be done with zero complications.

Unlike anterior cervical fusions, posterior fusions have not been shown to be associated with as much adjacent segment wear and tear. It may be jus that this technique is new. Nevertheless the joints above and below the fusion are prone to wear and tear and may require further surgery in the future. This is uncommon.

Expectations

The aim of surgery is typically to stop progression of myelopathy and any gains are a bonus. Typically:

• 40% get better
• 40% stay the same
• 20% continue to deteriorate

The operation is best performed before the myelopathy has progressed too far. The patient who starts in a wheelchair will probably stay there. Most patients do note some improvement.

The main advantage of doing a posterior decompression with a fusion is that a wide laminectomy can be performed and consequently the compression is relieved via a single-stage procedure and a further anterior approach is not required.

Recovery

A collar is placed and this is worn for 6 weeks. I let my patients take the collar off for showers and meals as long as they hold their head still. There is marked muscle spasm in the first 1-2 weeks after surgery and so headaches and neck pain are common. These are usually management by the use of muscle relaxants and analgesia and in almost all cases, the neck pain resolves in a few weeks. Typically 2-5 nights are required in hospital to allow the pain to settle.

Typical x-rays are shown below:

At discharge, the collar is worn for a total of 6 weeks. At that time flexion/extension x-rays of the cervical spine are taken and if these are satisfactory, the collar is discontinued over a period of 1-2 weeks. Initially, the neck is very stiff at this point, but with physiotherapy much of the movement returns. Because the operation is a fusion, there will always be some restriction in movement, when compared to an earlier date, but most patients do not find this restriction interferes with day to day life  (see below).

(Above): This woman underwent a C3-7 fusion and decompression and is photographed 6 weeks after surgery, showing an excellent range of movement.

Repeat MR scanning if performed on the cervical spinal cord will show an adequate decompression of the spinal cord (see below):

BEFORE SURGERY (note compression)   AFTER  SURGERY (note there is space around the cord)

I will typically follow my patients for 12 months with repeat x-rays to ensure no hardware-related complications. After that time, investigations are only performed if problems occur.

Non-Surgical Options

There are very few non-surgical options in terms of the management of cervical myelopathy. The only real option is to defer surgery if the patient feels the risks outweigh the benefits. There is no guarantee that they will deteriorate if they decide not to have surgery. Because the compression of the spinal cord is structural lesion, no physiotherapy, diet or alternative therapy will relieve the compression. Chiropracty is contraindicated as spinal manipulation can lead to spinal cord injury.

Other Points

Myelopathy is common and become more so as the population ages. Cervical laminectomy with lateral mass fusion is the most recent operation available to the spinal surgeon in the management of multilevel spinal cord compression. Because the compression is from the back as well as the front, artificial disc surgery may not be adequate to deal with this pathology is some patients, and here a laminectomy and fusion may indicated.