Osteoarthritis of the Spine
Updated: Nov 26, 2020
Arthritis is the most common cause of low back pain, especially in people over age 50. The low back contains five sets of facet joints, one on the left and one on the right side of each spinal bone. Like joints in any other part of the body the low back facet joints can be injured, or become inflamed.
This article provides a full review of the cause of spinal arthritis, its symptoms, as well as how to get an accurate diagnosis.
Quick Definition of Spinal Arthritis
The word arthritis comes from a combination of the Greek "arthros," meaning a joint and "-itis," meaning inflammation (swelling). The facets are the only joints in the spine. Spinal arthritis therefore means inflammation of the spinal facet joints.
Causes of Arthritis in the Lower Back
Arthritis of the spine usually occurs due to internal damage to the facet joints. The surfaces of the facet joints are lined with smooth cartilage to allow for movement as the two sides of the joint rub against one another. However, the joint can become painful through the following process:
The cartilage on one side of the facet joint gets damaged. Every time the spine moves the injured cartilage rubs against its neighbor, causing friction and further injury to both sides.
The joint damage and friction leads to inflammation.
The swollen facet joints transmit this pain signal through a single nerve (the medial branch) that travels through the facet joint.
This signal then causes the back muscles to go into spasm.
The combination of the muscle spasm and inflammation of the joints causes low back pain.
The spinal facet joints in the lower back are prone to developing osteoarthritis. The joints are quite small compared to the amount of body weight they bear. The resulting stress and strain makes them susceptible to damage to the cartilage, and injury. The accumulation of injuries over a lifetime causes the joints to break down, or degenerate.
Facet joint breakdown also comes as a result of herniated discs. Discs act as shock absorbers for the spine. They have a tough outer part, and a soft inner part. The soft inner part absorbs the shock. But the hard outer part can tear due to degeneration or even injury. The torn discs don’t absorb stress and strain very well, which leads to excessive force being transmitted to the facet joints.
The degenerative process is similar to what happens in a car. If the shocks go out and aren’t replaced, the next thing that happens is the springs break. In the lower back, once the torn disc stops absorbing the stresses and strain of everyday life, the facet joints go out next. Once the facet joints are injured they become inflamed, swell, cause muscle spasm, and the back pain cycle begins.
Symptoms of Arthritis of the Spine
Spinal arthritis causes stiffness and low back pain. The stiffness is worst upon waking up in the morning, tends to ease with activity, then worsens toward the end of the day. Presumably, this is because fluid has built up in the joint due to inactivity overnight, which causes more swelling.
The low back pain due to facet joint arthritis has a typical pattern:
The pain is mostly — more than 80% — in the back, runs into the buttocks, and often really feels like it’s in the hip.
As it gets even worse people often report burning on the outer aspect of the thigh, and sometimes pain down the leg.
Because the pain runs down the leg people, even doctors sometimes, confuse it with nerve root pain.
Typical Symptoms of Spinal Osteoarthritis
The full range of symptoms that typically occur with spinal arthritis includes some combination of the following:
The back and/or neck stiffness and pain tend to be worse in the morning (particularly for about 30 minutes after waking up), often called "first movement pain."
The pain will usually subside to a more tolerable level over the course of the day as the person carries on his or her activities.
Pain and stiffness tend to get worse again in the evening.
Pain that disrupts sleep is often an indicator of osteoarthritis.
Swelling and warmth in one or more joints, particularly during weather changes (which may be related to barometric pressure changes and cooling of the air).
Localized tenderness when the joint or affected area of the spine is pressed.
Steady or intermittent pain in a joint, which is often described as an aching type of pain. The pain may be aggravated by motion.
Loss of flexibility of a joint, such as inability to bend and pick something off the floor.
A crunching feeling or sound of bone rubbing on bone when the joint is moved (called crepitus), particularly notable in the neck.
A sensation of pinching, tingling, or numbness in a nerve or the spinal cord, which can occur when bone spurs form at the edge of the joints of the spine and irritate the nerves.
Facet joint pain and stiffness can begin to occur after long periods of inactivity, such as while sitting for long journeys or watching a two-hour movie. With advanced osteoarthritis and increased rasping friction between bones, the pain often becomes substantial even at rest or with very little movement.
With progressive osteoarthritis, a single joint may at first be affected, but with time and further activities, many joints of the body may be affected – in the base of the neck, or in the knees, hips, hands, and/or feet.
Although less common, some patients may experience severe deformities of certain joints over time. Osteoarthritis differs from rheumatoid arthritis and other systemic forms of arthritis because it only affects joints (although it may lead to an entrapment of a nerve at any level in the spine or the spinal cord in the neck) and does not affect organs or soft tissue areas of the body.
Diagnosis of Spinal Arthritis
Anyone with low back pain or stiffness for more than two weeks should consult a physician for a medical evaluation.
3-Part Process for Diagnosing Spinal Arthritis
In general, diagnosis spinal arthritis involves a 3-step process, starting with a complete medical history.
Medical history
The patient will be asked to describe his or her symptoms, such as a description of the pain, stiffness, and joint function, when and how the symptoms started, and how the symptoms have changed over time.
The patient should also discuss how the symptoms affect his or her everyday life and work activities.
The medical history will include the patient's other medical conditions, current medications, past experience with other treatments, family history, and general lifestyle habits (such as alcohol intake, smoking, etc.).
When dealing with pain problems, the doctor is likely to ask key questions related to those things that reliably cause or aggravate the pain and those that reliably bring relief or prevent the pain. Other questions may relate to certain lifestyle topics, such as exercise, nutrition, and activities for diversion, sports, etc.
Physical examination
The doctor will conduct a physical exam to assess the patient's overall general health, musculoskeletal status, nerve function, reflexes, and direct evaluation of the problematic joints in the back.
The doctor will be looking at muscle strength, flexibility, and the patient's ability to carry out daily living activities such as walking, bending, and reaching. The patient may also be asked to perform some exercises to test range of motion and determine whether pain worsens during any particular type of movement.
X-rays
The doctor may order an X-ray to see if there is joint damage and how much joint damage has occurred. The X-ray can show cartilage loss, compression fractures, and the presence and location of bone spurs. X-rays are also useful in helping to exclude other causes of pain and to better inform possible considerations for referral to a specialist.
However, it is important to keep in mind that what shows up in an X-ray may not correlate to the presence or absence of osteoarthritis and associated pain. For example;
Most people over age 60 have degenerative changes in their spine consistent with osteoarthritis, but for perhaps 85% of them there is no pain or stiffness.
Conversely, an X-ray conducted during the early stages of osteoarthritis may not yet show any visible damage to the joints, but the patient may have symptoms.
For all these reasons, the clinical history and physical examination are essential to arriving at an accurate clinical diagnosis and plan of treatment.
CT Scan
A CT scan may be used to better show the adequacy of the spinal canal and surrounding structures.
A CT scan may also include myelography, which involves an x-ray contrast dye that is injected into the spinal column to show issues such as a bulging disc or bone spur possibly pressing on the spinal cord or nerves.
MRI Scan
The MRI, or magnetic resonance imaging scan, is a sophisticated imaging method that can show detailed images of the spinal cord, nerve roots, discs, ligaments, and surrounding tissues and spaces.
Most MRI scans require the patient to lie flat in a tube for about 15-20 minutes. Open frame, and even standup, MRI scanners do exist and may be appropriate for patients having claustrophobia (fear of tight spaces).
MRI scans can be adjusted to show details of tissues, such as water content in the tissue, which may be important in determining disc degeneration, infections, or tumors.
Serious Conditions Related to Lower Back Pain
For symptoms of lower back pain PLUS any of the following red flags then a medical evaluation is an emergency, and should be done same day:
History of cancer, or unexplained weight loss
Symptoms of infection, such as fever, shakes, chills
Numbness in the perineum (genital areas) and urinary problems
Recent fall or trauma that may have caused spine fracture
Severe numbness or weakness in one or both legs
The evaluation usually consists of a discussion of symptoms and a detailed medical history, a physical examination, and X-rays of the low back.
Other tests (blood tests, MRI or CT scans) may be performed if there are red flags, or to confirm or exclude the presence other rare conditions that can cause similar symptoms, such as a spinal tumor, infection, fracture, or other types of arthritis.
The goal of all diagnostic studies is to discover patterns or confirmations between the various tests that point to a clear diagnosis among various possible ones.
The key is to diagnose the condition causing the patient's pain and disability, which includes putting all the pieces of the puzzle together and does not rely on diagnostic tests alone.