• Is a hydrostatic, load bearing structure between the vertebral bodies from C2-3 to L5-S1 .• Nucleus pulposus + annulus fibrosus• Is relatively avascular.• L4-5, largest avascular structure in the body.
Vital Functions of the IVD • Restricted intervertebral joint motion • Contribution to stability • Resistence to axial, rotational, and bending load • Preservation of anatomic relationshipThe Biochemical Composition • Water : 65 ~ 90% wet wt. • Collagen : 15 ~ 65% dry wt. • Proteoglycan : 10 ~ 60% dry wt. • Other matrix protein : 15 ~ 45% dry wt.
Annulus Fibrosus• Outer boundary of the disc.• More than 60 distinct, concentric layer of overlapping lamellae of type I collagen.• Fibers are oriented 30-degree angle to the disc space.• Helicoid pattern.• Resist tensile, torsional, and radial stress.• Attached to the cartilaginous and bony end-plate at the periphery of the vertebra.
Nucleus Pulposus Type II collagen strand + hydrophilic proteoglycan. Water content 70 ~ 90% Confine fluid within the annulus. Convert load into tensile strain on the annular fibers and vertebral end-plate.
Distribution of load in theintervertebral disc. (A) In the normal, healthy disc,the nucleus distributes the loadequally throughout the anulus. (B) As the disc undergoesdegeneration, the nucleus losessome of its cushioning abilityand transmits the loadunequally to the anulus. (C) In the severely degenerateddisc, the nucleus has lost all ofits ability to cushion the load,which can lead to discherniation
Is a medical condition affecting the spine due to trauma, lifting injuries, or idiopathic, in which a tear in the outer, fibrous ring (annulus fibrosus) of an intervertebral disc allows the soft, central portion (nucleus pulposus) to bulge out beyond the damaged outer rings. This tear in the disc ring may result in the release of inflammatory chemical mediators which may directly cause severe pain, even in the absence of nerve root compression . Disc herniations are normally a further development of a previously existing disc "protrusion", a condition in which the outermost layers of the annulus fibrosus are still intact, but can bulge when the disc is under pressure.
Types of herniation posterolateral disc herniation – protrusion is usually posterolateral into vertebral canal, compress the roots of a spinal nerve. protruded disc usually compresses next lower nerve as that nerve crosses level of disc in its path to its foramen. (eg.protrusion of fifth lumbar disc usually affects S1 instead. central (posterior) herniation: less frequently, a protruded disc above second lumbar vertebra may compress spinal cord itself or or may result in cauda equina syndrome. in the lower lumbar segments, central herniation may result in S1 radiculopathy. lateral disc herniation: may compress the nerve root above the level of the herniation L4 nerve root is most often involved & patient typically have intense radicular pain.
Classifications Of Herniations Degeneration Loss of fluid in nucleus pulposus Protrusion Bulge in the disc but not a complete rupture Prolapse Nucleus forced into outermost layer of annulus fibrosus- not a complete rupture Extrusion A small hole in annulus fibrosus and fluid moves into epidural space Sequestration Disc fragments start to form outside of the disc area.
Schematic illustrationa) Normalb) Bulging diskc) Focal bulge or protrusion.The nucleus material remainswithin the outermost fibres ofthe annulus fibrosus.d) Prolapse or extrusion.The nucleus material haspenetrated the annulusfibrosus but is contained infront of the posteriorlongitudinal ligament.e) Sequester or free fragment.
Cellular and Biochemical Changes of the Intervertebral Disc Decrease proteoglycan content. Loss of negative charged proteoglycan side chain. Water loss within the nucleus pulposus. Decrease hydrostatic property. Loss of disc height. Uneven stress distribution on the annulus.
CAUSES Repetitive mechanical activities – Frequent bending, twisting, lifting, and other similar activities without breaks and proper stretching can leave the discs damaged. Living a sedentary lifestyle – Individuals who rarely if ever engage in physical activity are more prone to herniated discs because the muscles that support the back and neck weaken, which increases strain on the spine. Traumatic injury to lumbar discs- commonly occurs when lifting while bent at the waist, rather than lifting with the legs while the back is straight.
CAUSES Obesity – Spinal degeneration can be quickened as a result of the burden of supporting excess body fat. Practicing poor posture – Improper spinal alignment while sitting, standing, or lying down strains the back and neck. Tobacco abuse – The chemicals commonly found in cigarettes can interfere with the disc’s ability to absorb nutrients, which results in the weakening of the disc. Mutation- in genes coding for proteins involved in the regulation of the extracellular matrix, such as MMP2 and THBS2, has been demonstrated to contribute to lumbar disc herniation.
Pathophysiology There is now recognition of the importance of “chemical radiculitis” in the generation of back pain. A primary focus of surgery is to remove “pressure” or reduce mechanical compression on a neural element: either the spinal cord, or a nerve root. But it is increasingly recognized that back pain, rather than being solely due to compression, may also be due to chemical inflammation.
There is evidence that points to a specific inflammatory mediator of this pain. This inflammatory molecule, called tumor necrosis factor-alpha (TNF), is released not only by the herniated disc, but also in cases of disc tear (annular tear), by facet joints, and in spinal stenosis. In addition to causing pain and inflammation, TNF may also contribute to disc degeneration
symptoms of a herniated disc can vary depending on the location of the herniation and the types of soft tissue that become involved. They can range from little or no pain if the disc is the only tissue injured, to severe and unrelenting neck or low back pain that will radiate into the regions served by affected nerve roots that are irritated or impinged by the herniated material. Often, herniated discs are not diagnosed immediately, as the patients come with undefined pains in the thighs, knees, or feet.
sensory changes such as numbness, tingling, muscular weakness, paralysis, paresthesia, and affection of reflexes. If the disc protrudes to one side, it may irritate the dural covering of the adjacent nerve root causing pain in the buttock, posterior thigh and calf (sciatica). Unlike a pulsating pain or pain that comes and goes, which can be caused by muscle spasm, pain from a herniated disc is usually continuous or at least is continuous in a specific position of the body.
A large central rupture may cause compression of the cauda equina. A posterolateral rupture presses on the nerve root proximal to its point of exit through the intervertebral foramen; thus a herniation at L4/5 will compress the fifth lumbar nerve root, and a herniation at L5/S1, the first sacral root. Sometimes a local inflammatory response with oedema aggravates the symptoms. …………………………………………………………………..
CLINICAL FEATURE OF ACUTE DISC PROLAPSE• Acute disc prolapse may occur at any age, but is uncommon in the very young and the very old.• The patient is usually a fit adult aged 20–45 years.• Typically, while lifting or stooping he has severe back pain and is unable to straighten up.• Either then or a day or two later pain is felt in the buttock and lower limb (sciatica).• Both backache and sciatica are made worse by coughing or straining.• Later there may be paraesthesia or numbness in the leg or foot, and occasionally muscle weakness.• Cauda equina compression is rare but may cause urinary retention and perineal numbness.
• The patient usually stands with a slight list to one side(‘sciatic scoliosis’).• Sometimes the knee on the painful side is held slightly flexed to relax tension on the sciatic nerve; straightening the knee makes the skew back more obvious.• All back movements are restricted, and during forward flexion the list may increase.
• There is often tenderness in the midline of the low back, and paravertebral muscle spasm.• Straight leg raising is restricted and painful on the affected side; dorsiflexion of the foot and bowstringing of the lateral popliteal nerve may accentuate the pain.• Sometimes raising the unaffected leg causes acute sciatic tension on the painful side (‘crossed sciatic tension’).• With a high or mid-lumbar prolapse the femoral stretch test may be positive.
• Neurological examination may show muscle weakness (and, later, wasting), diminished reflexes and sensory loss corresponding to the affected level.• L5 impairment causes weakness of knee flexion and big toe extension as well as sensory loss on the outer side of the leg and the dorsum of the foot.
• Normal reflexes at the knee and ankle are characteristic of L5 root compression.• Paradoxically, the knee reflex may appear to be increased, because of weakness of the antagonists (which are supplied by L5).• S1 impairment causes weak plantar-flexion and eversion of the foot, a depressed ankle jerk and sensory loss along the lateral border of the foot.
FEATURES OF CAUDA EQUINA SYNDROMEBladder and bowel incontinencePerineal numbnessBilateral sciatica .Lower limb weaknessCrossed straight-leg raising signNote: Scan urgently and operate urgently if a largecentral disc is revealed.
Signs and Symptoms• Most common sign or symptom is pain. Pain located in the buttock that radiates down the back of the thigh and possible the calf.
Location The majority of spinal disc herniation cases occur in lumbar region (95% in L4-L5 or L5-S1). The second most common site is the cervical region (C5-C6, C6-C7). The thoracic region accounts for only 0.15% to 4.0% of cases.
. The rest of the spinal cord, however, is oriented differently, so a symptomatic posterolateral herniation between two vertebrae will actually impinge on the nerve exiting at the next intervertebral foramen down. for example, a herniation of the disc between the L5 and S1 vertebrae will impinge on the S1 spinal nerve, which exits between the S1 and S2 vertebrae. Occasionally an L4/5 disc prolapse compresses both L5 and S1.
Cervical Cervical disc herniations occur in the neck, most often between the fifth & sixth (C5/6) and the sixth and seventh (C6/7) cervical vertebral bodies. Symptoms can affect the back of the skull, the neck, shoulder girdle, scapula, shoulder, arm, and hand. The nerves of the cervical plexus and brachial plexus can be affected.Thoracic Thoracic discs are very stable and herniations in this region are quite rare. Herniation of the uppermost thoracic discs can mimic cervical disc herniations, while herniation of the other discs can mimic lumbar herniations.
Lumbar Lumbar disc herniations occur in the lower back, most often between the fourth and fifth lumbar vertebral bodies or between the fifth and the sacrum. Symptoms can affect the lower back,buttocks, thigh, anal/genital region (via the Perineal nerve), and may radiate into the foot and/or toe. The sciatic nerve is the most commonly affected nerve, causing symptoms of sciatica. The femoral nerve can also be affected and cause the patient to experience a numbness, tingling feeling throughout one or both legs and even feet or even a burning feeling in the hips and legs.
DISC LOAD IN DIFFERENT BODY POSTURE When the spine is straight, such as in standing or lying down, internal pressure is equalized on all parts of the discs. While sitting or bending to lift, internal pressure on a disc can move from 17 (lying down) to over 300 psi (lifting with a rounded back).
Diagnosis Diagnosis is based on the history, symptoms, and physical examination. At some point in the evaluation, tests may be performed to confirm or rule out other causes of symptoms such as spondylolisthesis, degeneration, tumors, metastase s and space-occupying lesions, as well as to evaluate the efficacy of potential treatment options.
Physical Examinations Main article: Straight leg raise The Straight leg raise may be positive, as this finding has low specificity; however, it has high sensitivity. Thus the finding of a negative SLR sign is important in helping to "rule out" the possibility of a lower lumbar disc herniation. A variation is to lift the leg while the patient is sitting. However, this reduces the sensitivity of the test
Examination With the patient standing uprightlook at his general posture and note particularly the presence of any asymmetry or frank deformity of the spine .
hold the pelvisstable and ask thepatient to twist first toone side and then tothe other (rotation).Note that rotationoccurs almostentirely in the thoracicspine (e) and not in thelumbar spine.
With the patient upright, select two bony points 10 cm apart and mark the skin asthe patient bends forward, the two points should separate by at least a further 5 cm
Examination with the patient prone (a) Feel for tenderness, watching the patient’s face for any reaction. (b) Performing the femoral stretch test. You can test for lumbar root sensitivity either by hyperextending the hip or by acutely flexing the knee with the patient lying prone. Note the point at which the patient feels pain and compare the two sides. (c) While the patient is lying prone, take the opportunity to feel the pulses. The popliteal pulse is easily felt if the tissues at the back of the knee are relaxed by slightly flexing the knee.
X-Ray : lumbo-sacral spine; Narrowed disc spaces. Loss of lumber lordosis. Compensatory scoliosis.CT scan lumber spine; It can show the shape and size of the spinal canal, its contents, and the structures around it, including soft tissues. Bulging out disc.MRI lumber spine; Intervertebral disc protrusion. Compression of nerve root.Myelogram; pressure on the spinal cord or nerves, such as herniated discs, tumors, or bone spurs.
Treatment options Pain medications. Bed rest Oral steroids . Nerve root block . Surgery
Indicated treatment. Non-steroidal anti-inflammatory drugs (NSAIDs). Patient education on proper body mechanics. Physical therapy, to address mechanical factors, and may include modalities to temporarily relieve pain (i.e. traction, electrical stimulation massage). Oral steroids (e.g. prednisone or methylprednisolone). Epidural cortisone injection. Intravenous sedation, analgesia-assisted traction therapy (IVSAAT). Weight control. Tobacco cessation. Lumbosacral back support. anti-depressants.
Contraindicated treatment. Spinal manipulation: According to the WHO, in their guidelines on chiropractic practice, a frank disc herniation accompanied by progressive neurological deficits is a contraindication for manipulation. Inconclusive treatment. Non-surgical spinal decompression: A 2007 review of published research on this treatment method found shortcomings in most published studies and concluded that there was only "very limited evidence in the scientific literature to support the effectiveness of non-surgical spinal decompression therapy.“ Its use and marketing have been very controversial
The indications for surgery • persistent pain and signs of sciatic tension (especially crossed sciatic tension) after 2–3 1 weeks of conservative treatment. • a cauda equina compression syndrome – this is an emergency; 2 • neurological deterioration while under 3 conservative treatment;
surgical Surgery is generally considered only as a last resort, or if a patient has a significant neurological deficit. The presence of cauda equina syndrome is considered a medical emergency requiring immediate attention and possibly surgical decompression. Regarding the role of surgery for failed medical therapy in patients without a significant neurological deficit, a meta-analysis of randomized controlled trials by the Cochrane Collaboration concluded that "limited evidence is now available to support some aspects of surgical practice". More recent randomized controlled trials refine indications for surgery as follows:
The Spine Patient Outcomes Research Trial (SPORT) Patients studied "intervertebral disk herniation and persistent symptoms despite some nonoperative treatment for at least 6 weeks...radicular pain (below the knee for lower lumbar herniations, into the anterior thigh for upper lumbar herniations) and evidence of nerve-root irritation with a positive nerve-root tension sign (straight leg raise–positive between 30° and 70° or positive femoral tension sign) or a corresponding neurologic deficit (asymmetrical depressed reflex, decreased sensation in a dermatomal distribution, or weakness in a myotomal distribution)
Conclusions. "Patients in both the surgery and the nonoperative treatment groups improved substantially over a 2- year period. Because of the large numbers of patients who crossed over in both directions, conclusions about the superiority or equivalence of the treatments are not warranted based on the intent-to-treat analysis"
• The Hague Spine Intervention Prognostic Study Group• Patients studied "had a radiologically confirmed disk herniation...incapacitating lumbosacral radicular syndrome that had lasted for 6 to 12 weeks...Patients presenting with cauda equina syndrome, muscle paralysis, or insufficient strength to move against gravity were excluded."• Conclusions. "The 1-year outcomes were similar for patients assigned to early surgery and those assigned to conservative treatment with eventual surgery if needed, but the rates of pain relief and of perceived recovery were faster for those assigned to early surgery.
The objectives of surgical treatment1. relief of nerve compression.2. allowing the nerve to recover.3. relief of associated back pain.4. restoration of normal function.
Chemonucleolysis-• Chemonucleolysis is the term used to denote chemical destruction of nucleus pulposus [Cehmo+nucleo+lysis].• This involves intradiscal injection ofchymopapain which causes hydrolysis of he cementing protein of the nucleus pulposus.• This causes decrease in water binding capacity leading to reduction in size and drying the disc.• Chemonucleolysis is one of the methods to treat disc herniation not responding to conservative therapy
Intradiscal electrothermic therapy (IDET)• provides a new alternative to other surgical procedures for patients who suffer from back pain caused by certain types of disc problems.• It is a fairly advanced procedure made possible by the development of electrothermal catheters that allow for careful and accurate temperature control. The procedure works by cauterizing the nerve endings within the disc wall to help block the pain signals• IDET is a minimally invasive outpatient surgical procedure developed over the last few years to treat patients with chronic low back pain that is caused by tears or small herniations of their lumbar discs.
Discectomy/Microdiscectomy -• This procedure is used to remove part of an intervertebral disc that is compressing the spinal cord or a nerve root.
The Tessys method• The Tessys method (transforaminal endoscopic surgical system) is a minimally invasive surgical procedure to remove herniated discs .
Laminectomy-to relieve spinalstenosis or nervecompression
Hemilaminectomy - Hemilaminectomy is surgery to help alleviate the symptoms of an impinged or irritated nerve root in the spine
Lumbar fusion• Anterior lumbar fusion is an operation done on the front (the anterior region) of the lower spine. Fusion surgery helps two or more bones grow together into one solid bone. Fusion cages are new devices, essentially hollow screws filled with bone graft, that help the bones of the spine heal together firmly. Surgeons use this procedure when patients have symptoms from disc degeneration, disc herniation, or spinal instability.• lumbar fusion is only indicated for recurrent lumbar disc herniations, not primary herniations
Disc arthroplasty• Artificial Disc Replacement (ADR), or Total Disc Replacement (TDR), is a type of arthroplasty.• It is a surgical procedure in which degenerated intervertebral discs in the spinal column are replaced with artificial devices in the lumbar (lower) or cervical (upper) spine.• The procedure is used to treat chronic, severe low back pain and cervical pain resulting from degenerative disc disease.• Used for cases of cervical disc herniation
Dynamic stabilization• Dynamic stabilization is a surgical technique designed to allow for some movement of the spine, while maintaining enough stability to prevent too much movement.• If you need to undergo surgery for spinal disc problems, you may also need added stabilization of the spine to prevent additional problems
Nucleoplasty• Nucleoplasty is the most advanced form of percutaneous discectomy developed to date. Nucleoplasty uses a unique technology to remove tissue from the center of the disc. Tissue removal from the nucleus acts to “decompress” the disc and relieve the pressure exerted by the disc on the nearby nerve root . As pressure is relieved the pain is reduced
Epidemiology• Disc herniation can occur in any disc in the spine, but the two most common forms are lumbar disc herniation and cervical disc herniation.• The former is the most common, causing lower back pain (lumbago) and often leg pain as well, in which case it is commonly referred to assciatica.• Lumbar disc herniation occurs 15 times more often than cervical (neck) disc herniation, and it is one of the most common causes of lower back pain.• The cervical discs are affected 8% of the time and the upper- to-mid-back (thoracic) discs only 1 - 2% of the time.• The following locations have no discs and are therefore exempt from the risk of disc herniation: the upper two cervical intervertebral spaces, the sacrum, and the coccyx.
Epidemiology• Most disc herniations occur when a person is in their thirties or forties when the nucleus pulposus is still a gelatin-like substance.• With age the nucleus pulposus changes ("dries out") and the risk of herniation is greatly reduced.• After age 50 or 60, osteoarthritic degeneration (spondylosis) or spinal stenosis are more likely causes of low back pain or leg pain.• 4.8% males and 2.5% females older than 35 experience sciatica during their lifetime.• Of all individuals, 60% to 80% experience back pain during their lifetime.• In 14%, pain lasts more than 2 weeks.• Generally, males have a slightly higher incidence than females.
Spine: 15 January 2012 - Volume 37 - Issue 2 - p 140–149 Who Should Have Surgery for an Intervertebral Disc Herniation?:• Comparative Effectiveness Evidence From the Spine Patient Outcomes Research Trial Pearson, Adam MD, MS; Lurie, Jon MD, MS; Tosteson, Tor ScD; Zhao, Wenyan MS; Abdu, William MD, MS; Mirza, Sohail MD, MPH; Weinstein, James DO, MS Abstract• Study Design. Combined prospective randomized controlled trial and observational cohort study of intervertebral disc herniation (IDH), an as-treated analysis. Objective.• To determine modifiers of the treatment effect (TE) of surgery (the difference between surgical and nonoperative outcomes) for intervertebral disc herniation (IDH) using subgroup analysis. Summary of Background Data.• The Spine Patient Outcomes Research Trial demonstrated a positive surgical TE for IDH at the group level.• However, individual characteristics may affect TE.• No prior studies have evaluated TE modifiers in IDH. Methods.• IDH patients underwent either discectomy (n = 788) or nonoperative care (n = 404) and were analyzed according to treatment received.• Thirty-seven baseline variables were used to define subgroups for calculating the time- weighted average TE for the Oswestry Disability Index (ODI) across 4 years (TE = ΔODIsurgery −ΔODInonoperative).• Variables with significant subgroup-by-treatment interactions (P < 0.1) were simultaneously entered into a multivariate model to select independent TE predictors.
Future treatments may include stem cell therapy.• Doctors Victor Y. L. Leung, Danny Chan and Kenneth M. C. Cheung have reported in the European Spine Journal that "substantial progress has been made in the field of stem cell regeneration of the intervertebral disc.• Autogenic mesenchymal stem cells in animal models can arrest intervertebral disc degeneration or even partially regenerate it and the effect is suggested to be dependent on the severity of the degeneration.
The impact of the Spine Patient Outcomes Research Trial (SPORT) results on orthopaedic practice. J Am Acad Orthop Surg. 2012 Mar;20(3):160-6• Department of Orthopaedic Surgery, University of Cincinnati College of Medicine, Cincinnati, OH, USA.• Abstract• The benefits of spinal surgery for relief of low back and leg pain in patients with degenerative spinal disorders have long been debated. The Spine Patient Outcomes Research Trial (SPORT) was designed to address the need for high- quality, prospectively collected data in support of such interventions. SPORT was intended to provide an evidential basis for spinal surgery in appropriate patients, as well as comparative and cost-effectiveness data. The trial studied the outcomes of the surgical and nonsurgical management of three conditions: intervertebral disk herniation, degenerative spondylolisthesis, and lumbar spinal stenosis.• Both surgical and nonsurgical care of intervertebral disk herniation resulted in significant improvement in symptoms of low back and leg pain.• Still, the treatment effect of surgery for intervertebral disk herniation was less than that seen in patients who underwent surgical versus nonsurgical treatment of degenerative spondylolisthesis and lumbar spinal stenosis.• Across SPORT, more significant degrees of improvement with surgery were noted in chronic conditions of lumbar spinal stenosis and lumbar spinal stenosis with spondylolisthesis. In addition, no catastrophic progressions to neurologic deficit occurred as a result of watchful waiting.
[Lumbar epidural steroid injection: Is the success rate predictable?]. Department of Orthopedics and Traumatology, Başkent University, Adana Medical Center, Ankara, Turkey. email@example.com Abstract• OBJECTIVES:• The aim of this study was to determine the relation between the percent of canal compromise and success rate of epidural steroid injection (ESI) in patients with symptomatic lumbar herniated intervertebral discs.• METHODS:• Patients with lumbar herniated intervertebral disc suffering from leg pain and treated with ESI were selected. The axial magnetic resonance (MR) image showing the largest canal compromise by the herniated disc was selected for measurements. The canal area and discherniation area measurements were calculated from the total number of pixels per cross-sectional area, multiplied by a scan correction factor, mm2/pixel. The percent canal compromise was obtained by the disc herniation area divided by the canal cross-section area, multiplied by 100. For pain assessment, visual analog scale (VAS) was used before (pre-injection VAS) and a month after ESI (post-injection VAS). Demographic data, duration of symptoms, and location and type of herniation were also noted.• RESULTS:• 39 patients (14 male, 25 female) were included in this study. The mean age was 50.2±11.6 years (27-76). Twenty-one cases (51%) also had back pain. The mean percent canal compromise ratio was 36.1±2.4%. The mean duration of symptoms was 19.4±6.6 months. The post-injection VAS was significantly decreased when compared with pre-injection VAS (p<0.0001), and this significance was related with the duration of symptoms being <3 months (p=0.021). There was also a significant negative correlation between percent canal compromise and post-injection VAS (p=0.042). However, there was no correlation between post-injection VAS and age, sex, or location or type of herniation (p>0.05).• CONCLUSION:• It has been demonstrated that higher benefits of ESI were achieved in patients with short duration of symptoms and high percent of canal compromise.