The spine is made of 33 individual bones stacked one on top of the other. This spinal column provides the main support for your body, allowing you to stand upright, bend, and twist, while protecting the spinal cord from injury. Strong muscles and bones, flexible tendons and ligaments, and sensitive nerves contribute to a healthy spine. Yet, any of these structures affected by strain, injury, or disease can cause pain.
When viewed from the side, an adult spine has a natural S-shaped curve. The neck (cervical) and low back (lumbar) regions have a slight concave curve, and the thoracic and sacral regions have a gentle convex curve (Fig. 1). The curves work like a coiled spring to absorb shock, maintain balance, and allow range of motion throughout the spinal column.
Figure 1. The spine has three natural curves that form an S-shape; strong muscles keep our spine in alignment.
The abdominal and back muscles maintain the spine's natural curves. Good posture involves training your body to stand, walk, sit, and lie so that the least amount of strain is placed on the spine during movement or weight-bearing activities (see Posture). Excess body weight, weak muscles, and other forces can pull at the spine's alignment:
Figure 2. The five regions of the spinal column.
The two main muscle groups that affect the spine are extensors and flexors. The extensor muscles enable us to stand up and lift objects. The extensors are attached to the back of the spine. The flexor muscles are in the front and include the abdominal muscles. These muscles enable us to flex, or bend forward, and are important in lifting and controlling the arch in the lower back.
The back muscles stabilize your spine. Something as common as poor muscle tone or a large belly can pull your entire body out of alignment. Misalignment puts incredible strain on the spine (see Exercise for a Healthy Back).
Vertebrae are the 33 individual bones that interlock with each other to form the spinal column. The vertebrae are numbered and divided into regions: cervical, thoracic, lumbar, sacrum, and coccyx (Fig. 2). Only the top 24 bones are moveable; the vertebrae of the sacrum and coccyx are fused. The vertebrae in each region have unique features that help them perform their main functions.
The main function of the cervical spine is to support the weight of the head (about 10 pounds). The seven cervical vertebrae are numbered C1 to C7. The neck has the greatest range of motion because of two specialized vertebrae that connect to the skull. The first vertebra (C1) is the ring-shaped atlas that connects directly to the skull. This joint allows for the nodding or “yes” motion of the head. The second vertebra (C2) is the peg-shaped axis, which has a projection called the odontoid, that the atlas pivots around. This joint allows for the side-to-side or “no” motion of the head.
The spinal cord is about 18 inches long and is the thickness of your thumb. It runs from the brainstem to the 1st lumbar vertebra protected within the spinal canal. At the end of the spinal cord, the cord fibers separate into the cauda equina and continue down through the spinal canal to your tailbone before branching off to your legs and feet. The spinal cord serves as an information super-highway, relaying messages between the brain and the body. The brain sends motor messages to the limbs and body through the spinal cord allowing for movement. The limbs and body send sensory messages to the brain through the spinal cord about what we feel and touch. Sometimes the spinal cord can react without sending information to the brain. These special pathways, called spinal reflexes, are designed to immediately protect our body from harm.
Any damage to the spinal cord can result in a loss of sensory and motor function below the level of injury. For example, an injury to the thoracic or lumbar area may cause motor and sensory loss of the legs and trunk (called paraplegia). An injury to the cervical (neck) area may cause sensory and motor loss of the arms and legs (called tetraplegia, formerly known as quadriplegia).
Thirty-one pairs of spinal nerves branch off the spinal cord. The spinal nerves act as “telephone lines,” carrying messages back and forth between your body and spinal cord to control sensation and movement. Each spinal nerve has two roots (Fig. 8). The ventral (front) root carries motor impulses from the brain and the dorsal (back) root carries sensory impulses to the brain. The ventral and dorsal roots fuse together to form a spinal nerve, which travels down the spinal canal, alongside the cord, until it reaches its exit hole - the intervertebral foramen (Fig. 9). Once the nerve passes through the intervertebral foramen, it branches; each branch has both motor and sensory fibers. The smaller branch (called the posterior primary ramus) turns posteriorly to supply the skin and muscles of the back of the body. The larger branch (called the anterior primary ramus) turns anteriorly to supply the skin and muscles of the front of the body and forms most of the major nerves.
Figure 8. The ventral (motor) and dorsal (sensory) roots join to form the spinal nerve. The spinal cord is covered by three layers of meninges: pia, arachnoid and dura mater.
The spinal nerves are numbered according to the vertebrae above which it exits the spinal canal. The 8 cervical spinal nerves are C1 through C8, the 12 thoracic spinal nerves are T1 through T12, the 5 lumbar spinal nerves are L1 through L5, and the 5 sacral spinal nerves are S1 through S5. There is 1 coccygeal nerve.
Figure 9. The spinal nerves exit the spinal canal through the intervertebral foramen below each pedicle.
The spinal nerves innervate specific areas and form a striped pattern across the body called dermatomes (Fig. 10). Doctors use this pattern to diagnose the location of a spinal problem based on the area of pain or muscle weakness. For example leg pain (sciatica) usually indicates a problem near the L4-S3 nerves.
Figure 10. A dermatome pattern shows which spinal nerves are responsible for sensory and motor control of specific areas of the body.
The spinal cord is covered with the same three membranes as the brain, called meninges. The inner membrane is the pia mater, which is intimately attached to the cord. The next membrane is the arachnoid mater. The outer membrane is the tough dura mater (Fig. 8). Between these membranes are spaces used in diagnostic and treatment procedures. The space between the pia and arachnoid mater is the wide subarachnoid space, which surrounds the spinal cord and contains cerebrospinal fluid (CSF). This space is most often accessed when performing a lumbar puncture to sample and test CSF or during a myelogram to inject contrast dye. The space between the dura mater and the bone is the epidural space. This space is most often accessed to deliver anesthetic numbing agents, commonly called an epidural, and to inject steroid medication (see Epidural Steroid Injections).
There are a few different types of back surgery, including the traditional, or open approach, MISS, and laser back surgery. Below, we’ll explore what makes each technique different.
When pressure is placed on a nerve, it can lead to pain and discomfort.
In the spine, things like a herniated disc or a bone spur can often cause compression. An example of one such condition is sciatica, where the sciatic nerve becomes pinched, leading to pain in the lower back and leg.
Lasers can be used to help decompress the nerve, with the aim of relieving pain. This is done under local anesthesia, which means that the skin and surrounding muscles of your back will be numbed to pain. You may also be sedated for the procedure.
One of the more well-studied methods of laser back surgery is called percutaneous laser disc decompression (PLDD). This procedure uses a laser to remove disc tissue that may be causing nerve compression and pain.
During PLDD, a small probe containing a laser is passed into the core of the affected disc. This is accomplished with the help of imaging technology. Then, the energy from the laser is used to carefully remove tissue that may be pressing on the nerve.
The benefits of laser back surgery are that it’s less invasive than the traditional approach to back surgery. Additionally, it can be performed in an outpatient setting under local anesthesia. In many ways, it’s very similar to MISS.
There’s a limited amount of information regarding the overall effectiveness of laser back surgery in comparison to other methods.
One 2017 studyTrusted Source compared PLDD to another surgical approach called microdiscectomy. Investigators found that both procedures had a similar outcome over a two-year recovery period.
However, it should be noted that when discussing PLDD, the researchers included additional follow-up surgery after PLDD as part of a normal outcome.
Laser back surgery isn’t recommended for some conditions, such as degenerative spine diseases. Additionally, more complex or complicated conditions will often require a more traditional surgical approach.
One of the drawbacks to laser back surgery is that you could need an additional surgery for your condition. A 2015 studyTrusted Source found that microdiscectomy had a lower number of reoperations required compared to PLDD.
Additionally, a 2017 meta-analysis of seven different surgeries for herniated discs in the lumbar region found that PLDD ranked among the worst based off of success rate, and it was in the middle for reoperation rate.
Every procedure can have potential side effects or complications. This is also true for laser back surgery.
One of the main potential complications from laser back surgery is damage to the surrounding tissue. Because a laser is used for the procedure, heat damage can occur to surrounding nerves, bone, and cartilage.
Another possible complication is infection. This can occur during the placement of the probe if proper sanitization procedures aren’t followed. In some cases, you may be provided with prophylactic antibiotics to help prevent an infection.
Recovery time can vary by individual and the specific procedure performed. Some people may be able to return to normal activities relatively quickly, while others may require more time. How does laser back surgery compare to other types of back surgery?
Having a traditional back surgery requires a hospital stay after the procedure, and recovery may take many weeks. According to the Johns Hopkins Spine Service, people undergoing traditional spine surgery should expect to miss 8 to 12 weeks of work.
In contrast, MISS is often performed as an outpatient procedure, meaning that you can go home the same day. Generally speaking, people who’ve undergone MISS may return to work in around six weeks.
You may have read that laser back surgery has a faster recovery than other procedures. However, there’s actually been very little research into how the recovery time compares.
In fact, the 2015 studyTrusted Source discussed above found that recovery from microdiscectomy was faster than for PLDD.
Have medical questions? Connect with a board-certified, experienced doctor online or by phone. Pediatricians and other specialists available 24/7.
Laser back surgery is a type of back surgery that uses a laser to remove tissue that may be pressing on or pinching a nerve. The procedure is less invasive than other back surgery methods, but it may require additional follow-up surgeries.
So far, little concrete information is available on if laser back surgery is more beneficial than other types of back surgery. Additionally, comparisons of cost effectiveness compared to other methods have yet to be made.
If you need to have back surgery, you should discuss all the possible options with your doctor. That way, you’ll be able to receive the treatment that’s best for you.
A compression fracture or a break in one of your vertebra can be painful. It can also make it difficult to move freely. That’s because a break can result in bone fragments rubbing against each other. Surgery can help treat such fractures. For example, kyphoplasty and vertebroplasty are minimally invasive procedures that are often performed together. Usually, they can be done without a hospital stay.
In vertebroplasty, a doctor injects a cement mixture into the bone to give it strength.
Kyphoplasty makes room for the mixture. In this procedure, a doctor inserts and inflates a balloon to create an opening for the mixture. The balloon is removed after the cement is injected. Kyphoplasty is sometimes referred to as balloon vertebroplasty.
Both of these procedures are more likely to be successful if done within two months of a fracture diagnosis. They can help relieve pain and improve mobility when other measures fail to provide relief.
These procedures can be effective in treating people whose bones are weakened by cancer or whose vertebrae collapse due to osteoporosis, a disease that causes loss of bone density.
Kyphoplasty and vertebroplasty are used to mend recent fractures. However, they aren’t used as a preventive technique, even for osteoporosis. As well, they’re usually not advised for herniated disks, back arthritis, or curvature of the spine due to scoliosis.
These two procedures haven’t been extensively tested in younger, otherwise healthy people. The long-term effects of the bone cement aren’t known, so these procedures are generally reserved for older people.
Spinal surgery once meant large incisions, long recovery periods, and painful rehab. Fortunately, surgical advances like the microdiscectomy procedure have improved the process.
Microdiscectomy, also sometimes called microdecompression or microdiskectomy, is a minimally invasive surgical procedure performed on patients with a herniated lumbar disc. During this surgery, a surgeon will remove portions of the herniated disc to relieve pressure on the spinal nerve column.
After evaluation of your symptoms, x-rays and scans, surgeon may decide to offer you a course of spinal injections. The aim of the injections is to reduce the pain and inflammation, which in certain types of spinal problems, can be long lasting and may obviate the need for spinal surgery.
Blocks are injections of medication onto or near nerves. The medications that are injected include local anesthetics, steroids, and opioids. In some cases of severe pain it is even necessary to destroy a nerve with injections of phenol, pure ethanol, or by using needles that freeze or heat the nerves. Injections into joints are also referred to as blocks. Although not technically correct, such shorthand is commonly used.
There are different kinds of nerve blocks used for various purposes.
Various areas of pain require different nerve block types. Below are a few of the available nerve blocks and some parts of the body where they are used.
The Epidural means “around the spinal cord.” Typically, epidural injections are performed in a doctor’s office or the hospital. They’re usually given by anesthesiologists, physiatrists, or interventional radiologists with special training. Before receiving an epidural injection, you will probably undergo an imaging test. This may involve a CT scan or an MRI of the back. The test allows the doctor to identify possible causes of back pain.