TORN DISC
Torn Disc – Understanding Your Condition
A torn disc goes by many names – slipped disc, herniated disc, ruptured disc, extruded disc, prolapsed disc. These various terms are often used interchangeably – and often incorrectly – to refer to any number of conditions that can affect an intervertebral disc.
In the most basic of terms, a disc can develop a tear, or fissure, because of degenerative changes, injury, and many other factors. Symptoms can range from severe, crippling pain to a minor back or neck ache. In some cases, symptoms may never arise. A severely damaged disc can, however, significantly affect the overall function and stability of the spine.
The specifics surrounding the condition can be quite overwhelming and confusing to understand, especially during the initial diagnosis. If you are dealing with the effects of a torn disc, you likely want to better understand your condition, learn how it will affect the rest of your spine, find out if you’ll have to live with back or neck pain forever, and determine whether it will interfere with your everyday activities and lifestyle.
The following sections will attempt to answer these questions and give you a better overall view of your condition.
Anatomy of a Torn Disc
The human spine is a complex network of bones, joints, discs, nerves, muscles, ligaments, and tendons, all of which work together to keep the upper body upright and allow for a wide range of motion. The development of a torn disc can affect several other components of the spinal anatomy. For this reason, it can be helpful to have a general understanding of the spine’s main components and how they work together.
Vertebrae – The bones that form the spine. Most humans have 24 individual stacked vertebrae in the three regions of the spine: the cervical region, or neck, consists of seven vertebrae, while the thoracic (mid-back) and lumbar (lower back) segments have 12 and five vertebrae, respectively. Additionally, eight to 10 fused vertebrae form the sacrum and coccyx (tailbone) bones at the base of the spine. An individual vertebra has several main parts, including:
A vertebral body – a cylindrical base situated on the anterior (front side) portion of a vertebra; serves as platform for an intervertebral disc
Spinous and transverse processes – the bony projections on the posterior (back side) of a vertebra; what you can feel when you run your fingers down your neck and back
Superior and inferior articular processes – the upper and lower bony projections that serve to connect two vertebrae together and form facet joints
A vertebral foramen – the hole in the central (middle) part of a vertebra, through which the spinal cord runs
Intervertebral foramina – the small canals, one on either side, that are formed by two stacked vertebrae through which spinal nerve roots exit the spinal column; foramina are also present in the sacrum
Facet joints – The hinged connection points of two vertebrae. A facet joint is lined with smooth cartilage and is encapsulated in lubricating synovial fluid, essential components that allow the superior and inferior articular processes of a joint to glide effortlessly against each other while facilitating spinal movements.
Intervertebral discs – The spongy pads of cartilaginous material sandwiched between individual vertebrae (and attached to the vertebral bodies on the top and bottom) that effectively absorb shock and help facilitate certain spinal movements. A disc and its surrounding vertebrae are known as a spinal motion segment.
Spinal cord and related neural structures – The intricate network of nervous tissue that serves as a conduit for sensory (feeling) and motor (movement) communication between the brain and the rest of the body. The spinal cord runs from the base of the brain, through the vertebral foramina, and divides into a thick bundle of nerves (cauda equina, or “horse’s tail”) in the lower back. Along the length of the spinal cord, nerve roots branch off through the intervertebral foramina and, as spinal nerves, divide further to innervate other areas of the body.
Muscles, ligaments, and tendons – The soft tissues that support the spine. These components also work together to facilitate movement.
Keeping these spinal components and their various duties in mind, you can likely imagine that a torn disc can contribute to the eventual disruption of this intricate spinal system. Before exploring this further, let’s take a more in-depth look at the anatomy of an intervertebral disc itself, which can offer additional insight about the development of a torn disc and how it can affect the rest of the spine.
Each intervertebral disc consists of a tough outer wall, known as the annulus fibrosus; a gel-like center, called the nucleus pulposus; and two endplates.
Annulus fibrosus – The annulus fibrosus consists of tight, concentric bands of tissue called lamellae. These fibers are arranged in concentric circles around the inner core of the disc and provide a disc with the capability of sustaining and distributing significant load forces throughout the spine, as well as facilitating certain spinal movements. The outer one-third of the annular wall is innervated by nerve fibers.
Nucleus pulposus – This gelatinous substance is a matrix of water-attracting proteoglycan molecules (protein), collagen fibers, and nearly 80 percent water. Due to its semi-liquid nature, the nucleus pulposus can effectively absorb and distribute shock, and also provides a disc with some ability to expel toxins and pull in nutrients to remain healthy.
Vertebral endplates – The annular wall of a disc is connected to the upper and lower bodies of their adjacent vertebrae by tough, cartilaginous end plates. These structures assist in shock absorption throughout the spine and supply nutrients to discs, which are completely avascular, or without a blood supply.
These components are all important parts of a healthy disc. However, a disc tear can contribute to the overall weakening of the disc and may notably disrupt its normal function. There are three main types of disc tears, including:
Rim lesions – These are horizontal tears that affect the outer layers of the annular wall, but do not extend into the nucleus pulposus. Rim lesions, which are also known as peripheral or transverse tears, are typically located where the ligamentous tissue of the disc wall connects to the edges of the vertebral bodies.
Concentric tears – These circumferential tears develop when lamellae fibers split apart. Concentric tears tend to affect the middle and outer one-third of an affected disc, and rarely affect the nucleus pulposus.
Radial tears – These types of disc fissures are horizontal and usually extend from the nucleus pulposus to the outer layers of the annular wall. Radial tears are often associated with the development of a herniated or ruptured disc, particularly when a pressurized nucleus pulposus (intradiscal pressure) pushes into the tear from the inside out. In some instances, the inner core may completely break through the disc and leak into the spinal canal.
A torn disc exhibiting any one of these tears may or may not cause pain. This usually depends on whether the nerve fibers innervating the outer one-third of a disc are damaged or irritated by the inflammatory properties of the nucleus pulposus. Regardless, a torn disc is a weakened disc that can no longer provide the proper support to its adjacent vertebrae. A dysfunctional motion segment can lead to additional degenerative conditions, such as vertebral slippage, arthritic facet joints, spinal cord or nerve root compression, and others.
Causes and Risk Factors of a Torn Disc
There are an array of causes and risk factors associated with a torn disc. Typically, years of wear and tear are the primary reason for a healthy disc to become susceptible to damage. This age-related deterioration usually begins as a disc dehydrates. Additionally, microtraumas, or small injuries, to the disc can accumulate over time, contributing to the formation of annular tears and fissures. Scar tissue can form around some of these tears, namely rim lesions and concentric tears, but new fissures may eventually develop. This cyclical process of tearing and scarring can damage a disc’s annular nerve fibers and impede the nutrient absorption and toxin removal processes that are essential to a disc’s health. As a result, the water-attracting proteins in an affected disc’s inner core become less active and are unable to maintain a sufficient water supply, which further diminishes its properties of elasticity and shock absorption.
Clearly, the act of aging plays a major role in degenerative spine conditions like a torn disc. However, the majority of individuals diagnosed with a torn disc have been afflicted via several combined factors. Along with age-related degenerative changes, a torn disc may also be caused by:
Traumatic injuries – sudden, forceful blows to the back or neck can cause immediate disc tearing
Genetics – certain genes may predispose some individuals to weaker annuli fibrosi
Repetitive stress and strain – frequent occupational or recreational stressors, such as heavy vibrations during construction work or repeating certain movements while participating in sports, can contribute to the development of a torn disc
Weight gain – additional weight, particularly in the abdomen, forces the discs and other spinal components to work harder, which can accelerate degenerative changes
Smoking – toxins found in cigarettes can interfere with blood circulation and may directly contribute to the breakdown of a disc’s cartilaginous materials
Improper posture – similar to weight gain, poor posture increases the stress placed on the spinal components
Previous injuries – old injuries can weaken spinal components, which may make it easier for a disc to tear
Torn Disc – Symptoms
The symptoms associated with a torn disc can vary widely, based on the location of a damaged disc, the severity of its tear, and whether nerve compression, irritation, or damage is a factor. More specifically, a torn disc can be painful if its nucleus pulposus comes into contact with and inflames nerve fibers in the annulus fibrosus. Additionally, neuropathy (nerve pain) in the extremities may arise if the inner core leaks into the spinal canal and compresses the spinal cord or a nerve root.
For example, a lumbar disc that has not ruptured or herniated, but has an annular tear that damages the tiny nerve fibers in the outer wall, may only cause discogenic pain, or pain specifically from the disc itself. In this example, discogenic pain may translate to a dull ache in the lower back. Conversely, the same disc might never become symptomatic if nerve damage or irritation doesn’t occur. In another example, if a torn cervical disc ruptures, allowing the inner nucleus pulposus to leak out of the annular wall and compress a nearby nerve root in the spinal canal, chronic headaches could occur and symptoms of pain, numbness, muscle weakness, and tingling could affect the upper body.
A torn disc can affect any region of the spine, including the thoracic segment. However, the condition is most frequently diagnosed in the lower back and neck because of the extreme mobility and weight-bearing responsibilities of these areas.
In general, a cervical torn disc might lead to the development of one or more of the following symptoms:
Discogenic pain that arises as neck pain
Headaches
Radiculopathy, or radiating pain, that affects the shoulder, arm, hand, and fingers on one side of the body
Muscle spasticity and weakness
Tingling, or a pins-and-needles feeling, and numbness in one arm and hand
Pronounced leg muscle weakness, difficulty walking, or even paralysis from the cervical spine down, especially if severe spinal cord compression has occurred as a result of extruded torn disc material
Additionally, one or more of the following symptoms might arise in a patient with a torn lumbar disc:
Discogenic pain that translates as lower back pain
Radiculopathy that affects the lower back, buttock, hip, leg, and foot on one side of the body; this particular set of symptoms is also known as sciatica
Muscle weakness and spasms in the lower back, hamstrings, and calves
Numbness and tingling in the legs and feet
A pronounced change in gait, lower body paralysis, or bladder/bowel dysfunction if compression of the cauda equina has occurred (compression of the cauda equina is an emergency condition requiring immediate treatment)