Facet Joints (or Zygapophyseal Joints)
The facet joints are also termed zygapophyseal joints. Each vertebral body has four facet joints that work like hinges. These are the articulating (moving) joints of the spine that enable extension, flexion, and rotation. Like other joints, the bony articulating surfaces are coated with cartilage. Cartilage is a special type of connective tissue that provides a self-lubricating and low-friction gliding surface. Facet joint degeneration causes loss of cartilage and formation of osteophytes (eg, bone spurs). These changes may cause hypertrophy or osteoarthritis, also known as degenerative joint disease.
Bones and Ligaments Osteophytes
(eg, bone spurs) may form adjacent to the end plates, which may compromise blood supply to the vertebra. Further, the end plates may stiffen due to sclerosis; a thickening or hardening of the bone under the end plates. Ligaments are bands of fibrous tissue connecting spinal structures (eg, vertebrae) and protect against the extremes of motion (eg, hyperextension). However, degenerative changes may cause ligaments to lose some of their strength. The ligamentum flavum (a primary spinal ligament) may thicken and buckle posteriorly (behind) toward the dura mater (a spinal cord membrane).
Spondylosis Symptoms
Thoracic (Mid-Back) Pain associated with degenerative disease is often triggered by forward flexion and hyperextension. In the thoracic spine disc pain may be caused by flexion--facet pain by hyperextension.
Lumbar (Low Back) Spondylosis often affects the lumbar spine in people over the age of 40. Pain and morning stiffness are common complaints. Usually multiple levels are involved (eg, more than one vertebrae). The lumbar spine carries most of the body's weight. Therefore, when degenerative forces compromise its structural integrity, symptoms including pain may accompany activity. Movement stimulates pain fibers in the annulus fibrosus and facet joints. Sitting for prolonged periods of time may cause pain and other symptoms due to pressure on the lumbar vertebrae. Repetitive movements such as lifting and bending (eg, manual labor) may increase pain.
Courtesy of: http://www.spineuniverse.com/displayarticle.php/article1440.html
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Spondylolisthesis
Spondylolisthesis is the term used to describe the presence of a spondylolysis where there has also been forward translation of the vertebra with the lysis (usually L5), on the vertebra below (usually the sacrum).
In the majority of cases the degree of anterior translation is slight, but in approximately 20% of cases the displacement of the upper vertebra can be marked.
It can be congenital (born with it) associated with a “pars defect”, degenerative, or traumatic.
The development of a spondylolysis which then goes on to a spondylolisthesis is usually associated with significant low back pain, but in most cases the situation will stabilize and pain will settle. It is only where severe pain persists, or features of nerve root irritation or compression develop that surgical intervention is indicated at this stage.
In cases where symptoms resolve some activity modification may be required to reduce the risk of exacerbating episodes of pain. It is also General fitness to maintain abdominal musculature tone is important.
If symptoms persist surgical intervention may be considered, and would usually take the form of a spinal fusion. However despite the often impressive x-ray appearance of this condition surgery of this type is required in less than 20% of cases.
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Intra-operative Monitoring of Nerves (IOM) |
Back Strain or Sprain
A strain is a muscle or tendon injury; a sprain is a ligament injury.
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Back strain is also referred to as pulled back muscles.
Simple strains are the most common cause of back pain, especially lower back pain. Muscle strain is often caused by overuse of a muscle or overloading a muscle. When a muscle is stressed beyond its limits, injury occurs.
A muscle strain (or pulled muscle) is an overstretched or torn muscle. With injury comes inflammation, which is part of the healing process. Inflammation causes pain and can also trigger muscle spasms. The severity of a muscle strain can range from mild to severe.
Back Muscle Strain may be Caused by Overload
Strained back muscles can occur when the back is overloaded - such as when lifting something too heavy. Weak muscles are more easily overloaded and injured than strong muscles, but any muscle can be overloaded.
Poor lifting techniques as well as lifting objects that are too heavy can overload the back and cause strained back muscles. Falling down or an unexpected twisting of the back can also cause pulled back muscles.
Though the pain is usually caused by overstretching or tearing of back muscles, sometimes an irritated spinal joint triggers muscle spasms around the joint.
Back Muscle Strain may be Caused by Overuse
Back pain often occurs when a muscle contraction is held too long. The body is made to move. When one position is held too long, the back muscles get fatigued and strained. Switching positions shift the workload to another group of muscles, preventing one muscle group from becoming fatigued.
Poor posture also cause the muscles to have to work harder to support the spine, which leads to fatigue, strain, and back pain.
The lower back is most commonly strained, as the lower back must support the weight of the upper body, whether standing or sitting.
Symptoms of Back Muscle Strain
Symptoms of pulled back muscles include back pain and muscle weakness and sometimes back muscle spasms. The back pain may be sudden, but usually comes on gradually.
The muscles stiffen or spasm to reduce motion to prevent further injury. Muscle injuries cause inflammation - a part of the healing process. Inflammation may trigger muscle spasms. Muscle spasms are more likely to be a problem for the first couple of days after an injury - when inflammation is at its worst. Though not serious, back muscle spasms can cause significant pain. Inflammation also causes pain.
Back Strain Prognosis
Healing time depends on the severity of the strain. Mild muscle strains usually heal within two weeks. Moderate muscle strains may take six to eight weeks to heal.
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Sciatica
The term sciatica describes the symptoms of leg pain and possibly tingling, numbness or weakness that travels from the low back through the buttock and down the large sciatic nerve in the back of the leg. The vast majority of people who experience sciatica get better with time (usually a few weeks or months) and find pain relief with non-surgical treatment. For others, however, sciatica can be severe and debilitating.
The clinical diagnosis of sciatica is referred to as a "radiculopathy", which means simply that a disc has protruded from its normal position in the vertebral column and is putting pressure on the radicular nerve (nerve root) in the lower back, which forms part of the sciatic nerve.
An important thing to understand is that sciatica is a symptom of a problem—of something compressing or irritating the nerve roots that comprise the sciatic nerve—rather than a medical diagnosis or medical disorder in an of itself. This is an important distinction because it is the underlying diagnosis (vs. the symptoms of sciatica) that often needs to be treated in order to relieve sciatic nerve pain. Common causes of sciatica are a lumbar herniated disc, spinal stenosis, degenerative disc disease or spondylolisthesis.
Sciatica occurs most frequently in people between 30 and 50 years of age. Often a particular event or injury does not cause sciatica, but rather it tends to develop as a result of general wear and tear on the structures of the lower spine.
Sciatica symptoms
For some people, the pain from sciatica can be severe and debilitating. For others, the pain might be infrequent and irritating, but has the potential to get worse.
While sciatica can be very painful, it is rare that permanent nerve damage (tissue damage) will result. Most sciatica pain syndromes result from inflammation and will get better within two weeks to a few months. Also, because the spinal cord is not present in the lower (lumbar) spine, a herniated disc in this area of the anatomy does not present a danger of paralysis.
Sciatica symptoms that may constitute a medical emergency include:
- Progressive weakness in the leg
- Bladder/bowel incontinence or dysfunction.
Patients with either of the above symptoms may have cauda equina syndrome and should seek immediate medical attention. In general, patients with complicating factors should contact their doctor if sciatica occurs, including people who: have been diagnosed with cancer; take steroid medication; abuse drugs; have unexplained significant weight loss; or have HIV.
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Spinal Stenosis
Spinal stenosis is a narrowing of the spinal canal, which places pressure on the spinal cord. If the stenosis is located on the lower part of the spinal cord it is called lumbar spinal stenosis. Stenosis in the upper part of the spinal cord is called cervical spinal stenosis. While spinal stenosis can be found in any part of the spine, the lumbar and cervical areas are the most commonly affected.
What Causes Spinal Stenosis?
Some patients are born with this narrowing, but most often spinal stenosis is seen in patients over the age of 50. In these patients, stenosis is the gradual result of aging and “wear and tear” on the spine during everyday activities. There most likely is a genetic predisposition to this since only a minority of individuals develops advanced symptomatic changes. As people age, the ligaments of the spine can thicken and harden (called calcification). Bones and joints may also enlarge, and bone spurs (called osteophytes) may form. Bulging or herniated discs are also common. Spondylolisthesis (the slipping of one vertebra onto another) also occurs and leads to compression. When these conditions occur in the spinal area, they can cause the spinal canal to narrow, creating pressure on the spinal nerve.
Symptoms of Stenosis
The narrowing of the spinal canal itself does not usually cause any symptoms. It is when inflammation of the nerves occurs at the level of increased pressure that patients begin to experience problems. Patients with lumbar spinal stenosis may feel pain, weakness, or numbness in the legs, calves or buttocks. In the lumbar spine, symptoms often increase when walking short distances and decrease when the patient sits, bends forward or lies down. Cervical spinal stenosis may cause similar symptoms in the shoulders, arms, and legs; hand clumsiness and gait and balance disturbances can also occur. In some patients the pain starts in the legs and moves upward to the buttocks; in other patients the pain begins higher in the body and moves downward. This is referred to as a “sensory march”. The pain may radiate like sciatica or may be a cramping pain. In severe cases, the pain can be constant. Severe cases of stenosis can also cause bladder and bowel problems, but this rarely occurs. Also paraplegia or significant loss of function also rarely, if ever, occurs.
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Herniated Discs
When people say they have a "slipped" or "ruptured" disk in their neck or lower back, what they are actually describing is a herniated disk-a common source of pain in the neck, lower back, arms, or legs.
Anatomy
Disks are soft, rubbery pads found between the hard bones (vertebrae) that make up the spinal column. The spinal canal is a hollow space in the middle of the spinal column that contains the spinal cord and other nerve roots. The disks between the vertebrae allow the back to flex or bend. Disks also act as shock absorbers.
Disks in the lumbar spine (low back) are composed of a thick outer ring of cartilage (annulus) and an inner gel-like substance (nucleus). In the cervical spine (neck), the disks are similar but smaller in size.
Cause
A disk herniates or ruptures when part of the center nucleus pushes through the outer edge of the disk and back toward the spinal canal. This puts pressure on the nerves. Spinal nerves are very sensitive to even slight amounts of pressure, which can result in pain, numbness, or weakness in one or both legs.
Risk Factors/Prevention
In children and young adults, disks have high water content. As people age, the water content in the disks decreases and the disks become less flexible. The disks begin to shrink and the spaces between the vertebrae get narrower. Conditions that can weaken the disk include:
- Improper lifting
- Smoking
- Excessive body weight that places added stress on the disks (in the lower back)
- Sudden pressure (which may be slight)
- Repetitive strenuous activities
Symptoms
Low back pain affects four out of five people. Pain alone is not enough to recognize a herniated disk. See your doctor if back pain results from a fall or a blow to your back. The most common symptom of a herniated disk is sciatica—a sharp, often shooting pain that extends from the buttocks down the back of one leg. It is caused by pressure on the spinal nerve. Other symptoms include:
- Weakness in one leg
- Tingling (a "pins-and-needles" sensation) or numbness in one leg or buttock
- Loss of bladder or bowel control (If you also have significant weakness in both legs, you could have a serious problem and should seek immediate attention.)
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