Lumbosacral Radiculopathy

Lumbosacral radiculopathy affects millions of people worldwide, causing pain that radiates from the lower back down through the legs. While it’s a leading cause of disability in younger adults, most cases respond well to treatment without surgery.

Table of contents

• What Is Lumbosacral Radiculopathy?
• Understanding the Spine and Nerve Roots
• What Causes This Condition?
• Signs and Symptoms
• Who Is Affected?
• How Is It Diagnosed?
• Treatment Options
• Possible Complications

What Is Lumbosacral Radiculopathy?

Lumbosacral radiculopathy is a condition that occurs when a nerve root in the lower back becomes compressed, irritated, or inflamed. This compression causes pain and other symptoms that can travel from the low back down into one or both legs^[1]. The condition is also commonly known as sciatica when the pain follows the path of the sciatic nerve down the back of the leg^[3].

sciatica, radiculitis

The term radiculopathy describes pain that radiates along a nerve path and is often described by patients as electric, burning, or sharp. This is different from simple muscle soreness because it involves actual nerve irritation or damage^[9].

Understanding the Spine and Nerve Roots

• Lumbar spine (lower back vertebrae)
• Intervertebral discs
• Spinal canal
• Nerve roots
• Sciatic nerve

To understand lumbosacral radiculopathy, it helps to know how the spine works. The spine is made up of 33 bones called vertebrae that are stacked on top of each other. The lumbar spine contains the 5 vertebrae in the lower back^[7].

Between each vertebra is a soft pad of tissue called an intervertebral disc. These discs act as shock absorbers and spacers for the spine. The vertebrae form a tunnel called the spinal canal, which protects the spinal cord running through it^[3].

The spinal cord is a long bundle of nerves that runs down the back through the spinal canal. Nerve roots branch off from the spinal cord and exit through openings between the vertebrae. These nerves travel out to different parts of the body, including the hips, legs, and feet. The part of the nerve closest to the spinal canal is called the nerve root^[3].

The sciatic nerve is a large nerve formed from several nerve roots in the low back. This nerve extends down the back of the leg to the foot. Because the sciatic nerve is commonly involved in lumbosacral radiculopathy, the condition is often called sciatica^[3].

What Causes This Condition?

Lumbosacral radiculopathy typically occurs when nerve roots become compressed or irritated. This can happen suddenly from an injury or develop gradually over time due to wear and tear on the spine^[5].

The most common causes include problems with the structures in and around the spine. A herniated disc (also called a ruptured or slipped disc) occurs when the inner material of a spinal disc pushes outward and presses on a nearby nerve root. This is one of the most frequent causes of nerve root compression^[4].

Degenerative disc disease is another common cause. As people age, spinal discs naturally lose fluid and elasticity. This can reduce the space between vertebrae and increase the likelihood of nerves becoming compressed^[13].

Spinal stenosis occurs when the spinal canal or the openings where nerves exit become narrowed. This narrowing, often due to arthritis or disc degeneration, reduces the available space for nerves and can cause compression^[3].

Bone spurs, or abnormal bone growths called osteophytes, can form on vertebrae due to joint degeneration. When these grow near nerve pathways, they may compress or irritate spinal nerves^[5].

Spondylolisthesis occurs when one vertebra slips forward over another. This shift can squeeze or stretch nerve roots, causing significant discomfort^[3].

Other contributing factors include aging, injury, poor posture, excess body weight, repetitive lifting, participating in weight-bearing sports, obesity, smoking, and sedentary lifestyles^[15]. Less commonly, conditions such as diabetes, infection, or a tumor can cause nerve compression^[3].

Sudden injury can occur with a fall, when lifting an object awkwardly, or through trauma such as a car accident. A slow onset of radiculopathy can develop from sitting or standing with poor posture for weeks, months, or years. Poor posture can slowly overstretch ligaments in the back, allowing pressure to build on spinal nerves^[15].

Signs and Symptoms

Lumbosacral radiculopathy can cause a variety of symptoms. The type and location of symptoms depend on which nerve root is affected and how much pressure is being placed on it^[5].

Pain is the most common symptom. It usually starts in the low back and can travel down the buttocks and the back of the leg, sometimes extending below the knee to the calf or foot. The pain is typically described as burning, lancinating (sharp and cutting), stabbing, throbbing, aching, or shooting^[5][15].

The pain may occur with or without low back pain. It usually affects one leg but can affect both. Pain and other symptoms can be constant or come and go, and their intensity can vary. Greater nerve irritation causes pain to spread farther along the nerve path^[5].

Other common symptoms include numbness or tingling in the back, hip, leg, or foot. Many people experience muscle weakness in the affected leg, making it difficult to walk or stand. Some people report muscle spasms or tightness^[3][15].

Certain activities can make symptoms worse. Pain may increase when coughing, sneezing, reaching, or sitting. The Valsalva maneuver (bearing down as if having a bowel movement) can also worsen pain^[5][15].

Some people find they cannot bend or rotate their back normally. They may be unable to stand up straight or find themselves “stuck” in a position such as stooped forward. Getting up from a chair may be difficult, and remaining in one position for a long time can cause increased discomfort. Pain is often worse in the morning, and some people develop a limp when walking^[15].

Nerve root compression can affect reflexes. For example, compression at the L5-S1 level may affect the ankle jerk reflex, while compression at L3-L4 may affect the knee jerk reflex^[5].

Who Is Affected?

Lumbosacral radiculopathy occurs in approximately 3 to 5 percent of the population. It affects both men and women, although the age at which symptoms appear differs slightly between the sexes. Men are most commonly affected in their 40s, while women are most commonly affected between ages 50 and 60^[6].

The condition most often affects people aged 30 to 50 years^[15]. Low back pain, which can include radiculopathy, ranks as one of the primary causes of disability in individuals aged 45 and younger in the developed world^[1].

Of those who develop lumbosacral radiculopathy, 10 to 25 percent will have symptoms that persist for more than 6 weeks^[6].

How Is It Diagnosed?

Lumbosacral radiculopathy is suspected based on characteristic pain patterns and a physical examination. During the examination, a healthcare provider will test strength, reflexes, and sensation to identify which nerve roots may be affected^[5].

One common test is the straight leg raise, also called the Lasègue test. During this test, the patient lies down and the healthcare provider slowly raises the affected leg. If this causes pain that radiates down the leg when the leg is lifted to 60 degrees or less, it suggests nerve root compression. This test is sensitive for detecting radiculopathy. An even more specific finding is when lifting the opposite (unaffected) leg causes pain in the affected leg^[5].

The straight leg raise can also be performed while the patient sits with the hip flexed at 90 degrees. The lower leg is slowly raised until the knee is fully extended. If radiculopathy is present, pain in the spine and often radiating symptoms occur as the leg is extended^[5].

If neurologic deficits are present or if symptoms persist for more than 6 weeks, imaging studies should be performed^[5].

Magnetic resonance imaging (MRI) is the most accurate way to diagnose structural abnormalities causing lumbosacral radiculopathy, including herniated discs and spinal stenosis. Alternatively, computed tomography (CT) scans can be used^[5].

Electrodiagnostic studies, including electromyography (EMG) and nerve conduction studies, can confirm the presence and degree of nerve root compression. These studies can identify whether the problem involves single or multiple nerve levels and help determine whether clinical findings match with abnormalities seen on imaging studies^[5].

These diagnostic tests can also help exclude other conditions that may mimic lumbosacral radiculopathy, such as peroneal nerve palsy, multiple mononeuropathy, or polyneuropathy^[5].

Treatment Options

The majority of lumbosacral radiculopathy cases recover without surgery and respond well to conservative treatment^[15].

Conservative Management

Initial treatment focuses on relieving symptoms and improving function. This typically includes prescription and over-the-counter pain medicines to help relieve pain, swelling, and irritation. Common medications include nonsteroidal anti-inflammatory drugs (NSAIDs), acetaminophen, and gabapentin^[1][3].

Some patients benefit from limiting positions and activities that increase pain. However, lying in bed or avoiding all movement is only recommended for a short period of time, as prolonged inactivity can worsen the condition^[3].

Physical therapy plays a central role in treatment. Physical therapists design individualized treatment programs to help reduce pain, regain normal movement, and restore function. Treatment may include exercises and stretches specifically tailored to the patient’s condition^[3][15].

A common approach called “back school” teaches patients back-protection techniques such as proper lifting methods and posture awareness. Lumbar stabilization programs help patients learn techniques to control their back pain while strengthening the stabilizing muscles of the lumbar spine. This may involve the McKenzie exercise program, which consists of repetitive lumbar spine exercises for managing low back pain^[10].

Core strengthening is widely advocated as a way to improve muscular control around the lumbar spine and maintain functional stability. The core muscles include the abdominal muscles in front, the paraspinal muscles and gluteal muscles in back, the diaphragm as the roof, and the pelvic floor and hip girdle muscles as the floor. A typical program consists of graded exercises that promote movement awareness, motor relearning, and strengthening^[10].

Soft-tissue techniques such as manual therapy, myofascial release, or massage may help improve the soft-tissue component of pain^[10].

Steroid injections into the lower back may help relieve symptoms temporarily^[3].

For patients who are overweight, a weight-loss program may help relieve symptoms by reducing stress on the spine^[3].

Surgical Treatment

Surgery may be necessary in some cases, depending on the cause, symptoms, and how long the pain has lasted. Most sources agree on urgent indications for surgical intervention, including significant or progressive motor deficits (muscle weakness) and cauda equina syndrome with bowel and bladder dysfunction^[10].

Surgical options include simple discectomy, discectomy plus fusion, percutaneous discectomy, and microdiscectomy. Ninety percent of patients who have surgery for lumbar disc herniation undergo discectomy alone. The complication rate of simple discectomy is reported at less than 1 percent^[10].

Possible Complications

If left untreated, lumbosacral radiculopathy can lead to long-term problems. Over time, irritated and inflamed nerves may become damaged, potentially leading to permanent numbness or weakness in the legs and feet^[3].

Patients should contact their healthcare provider right away if they experience new pain or pain that gets worse, new or increasing weakness, tingling, or numbness in the leg or foot, or problems controlling the bladder or bowel. Loss of bladder or bowel control is a medical emergency that requires immediate attention^[3][5].

If symptoms change suddenly or get worse, it is important to notify a healthcare provider promptly^[3].