What is Spondylolisthesis?
Spondylolisthesis is an injury that affects the spine. It involves the fracture and slipping of one vertebrae relative to the others. While this may sound like a terrible injury, it can often be undiagnosed due to not causing any symptoms. In cases where it is diagnosed, it is important to understand its cause, symptoms, and treatment options.
First, understanding spondylolisthesis means conceptualizing the spine. Our spine consists of vertebrae stacked on top of one another with discs in between. We have curves in our spine to absorb force, so slight curves are expected. However, if one vertebrae suffers a fracture, it can move relative to others as shown in this picture below:
The pars interarticularis is a thinner section of bone that connects the body of the vertebrae to the spinous process that projects backwards. When there is a fracture of the pars interarticularis, it is called a spondylolysis (read more about the differences between the two here courtesy of the American Academy of Orthopedic Surgeons). If the fracture progresses to the point that the vertebral body shifts forward, as shown in the image above, then it is termed a spondylolisthesis (further information on this can be found here from the Cleveland Clinic).
Most often, the spondylolisthesis occurs at the L5 or lowest lumbar vertebrae above your sacrum or tailbone. This area is most commonly injured for two reasons: one, there is more aggressive sloping of the lumbar spine where it meets the sacrum, and two there is more motion at the lower lumbar spine. More motion leads to more opportunity for wear and tear leading to a fracture.
The most commonly accepted grading scale for spondylolisthesis uses four steps of increasing slippage of the vertebrae. The image below does an excellent job of highlighting the progression.
The vertebra in the image has slipped 25% of its length, meaning it is a Grade 1 classification. A Grade 2 involves a slipping of 50%, Grade 3 involves 75%, and Grade 4 is 100% slippage. Later on, I will discuss how different grades of spondylolisthesis are managed, but it is important to note that most cases are a Grade 1 and are asymptomatic. Physicians will often find evidence of some slippage on imaging, but it may have never been a cause of pain and is thus not worth addressing at the time. Wear and tear can be a normal part of aging. Thinking that your vertebrae have “shifted” can be daunting, but most cases involve a gradual change over time. You have probably had a spondylolisthesis for a long time and never noticed it. Hopefully that decreases some stress you may be experiencing.
Spondylolisthesis Symptoms and Cause
There are several common causes of spondylolisthesis, but there are three that are most common:
Isthmic spondylolisthesis typically occurs in younger men who participate in sports that involve frequent hyperextension of the low back. These athletes typically do not have enough strength to support the load being placed on their back, and the spine itself is subject to repetitive stress and load. Football offensive linemen are one of the most common candidates due to them resisting defensive linemen in an extended posture as shown below:
The player is in a position where he is subject to significant force, but he is unable to brace in any way to protect himself. Other sports such as baseball that involve repetitive rotation can also create risk for spondylolisthesis. Only one side of the pars interarticularis may fracture from repetitive movements such as a right handed player who swings a bat hundreds of times a day in one direction.
Degenerative spondylolisthesis is another common cause, particularly in women older than 50. The primary cause of this is thought to be a decrease in bone density along with repetitive loading and poor muscular support. This is not typically related to occupation or activities, but more closely related to lifestyle factors and exercise.
The final cause type of spondylolisthesis is traumatic. This is relatively self-explanatory as trauma is involved. Motor vehicle accidents are a common cause as there can be rapid shearing forces through the spine. Prevention of this type of spondylolisthesis is obviously difficult given the random nature.
Symptoms of spondylolisthesis can vary, but they typically involve low back pain around the injury site. Pain is usually worse with extension because this compresses the injured area and can create further shearing force. Rotation can also be painful, as it stresses one side of the spine. Standing is often painful because it is an extended position and also there is no support for the injured tissue. Sitting or lying down is typically easier to tolerate because there is more flexion, but also because the segment is supported.
Nerve pain can occur, particularly in grade 3 or 4 spondylolisthesis due to compression of the nerve roots. Damage to the L5 region typically manifests in pain in the calf or foot along with possible numbness or tingling. Weakness may be present in the calf muscles in some cases. Not all significant grades cause neurological symptoms, but they can be a sign that aggressive intervention is required.
Diagnosing spondylolisthesis is straightforward with a simple standing x-ray to determine bony position and assigning of a grade. An MRI may be necessary to determine soft tissue involvement and nerve compression depending on the findings.
Primary treatment for spondylolisthesis can involve rest for the affected area and spinal segment. Inflammation and irritation of the surrounding tissues is often a cause of pain, and relative rest can be beneficial. More time sitting or lying down can provide a flexed position and outside support for the body as previously mentioned. Abdominal braces can also be used in certain cases to limit movement between the spinal segments with activity.
Extension and rotation should be avoided temporarily to allow the tissues to heal. Many times, people think that mobility is a limiting factor when it comes to back pain, but this is not the case in spondylolisthesis. In fact, there is too much movement at the affected segment. Chasing more mobility is one of the worst things that you can do.
Similarly, aggressive rotational movements and stretches should be avoided. However, if you are able to localize stretches and mobility drills to the tissue and segments above and below the spondylolisthesis, you may see some benefit. Typically, the low back takes increased load due to limited mobility of the thoracic spine and hips. The lumbar spine is not designed to twist, but it may be forced to do so if the thoracic spine does not move correctly. Stretches and exercises designed for thoracic rotation and extension can help unload the stressed lumbar spine and allow for healing. Similarly, hip mobility drills and exercises can be beneficial, as long as they do not create a stretch in the lumbar spine.
Trigger point dry needling is a popular modality for pain relief, and one that I have found beneficial for many patients. It may be useful to increase mobility of the thoracic and hip muscles, but you should be cautious about utilizing it near the lumbar spine. The segment that is slipped forward is typically held in place by the surrounding muscles. This may create stress and irritation of those muscles, but dry needling can create too much relaxation, causing the segment to shift further. If you are going to utilize trigger point dry needling in the area of the spondylolisthesis, you need to have an excellent rationale and know what muscles you are targeting.
Grade 3 and 4 spondylolisthesis may require surgical intervention including possible fusion of the segments. While this is not ideal, it may be necessary to prevent neurological damage or worsening symptoms. Hopefully, conservative treatment can prevent the spondylolisthesis from progressing to this point.
Eventually, you will be able to progress exercises to include a greater focus on strength to help with pain, but also prevent further slippage of the segment. Exercises should be focused on flexion first, including sitting exercises or using a posterior pelvic tilt. This creates less stress and shear at the lumbar segment and allows for strengthening of core muscles that can provide stability.
Isometric exercises for the rotation muscles such as your multifidi can be very beneficial as long as it is tolerated. A Pallof Press like the one shown below is an excellent starting point that I frequently utilize with clients:
This exercise forces you to resist rotation and helps strengthen the obliques, which provide global stability, as well as the multifidi which hold individual spinal segments in position. There are many progressions including having one foot in front of the other or standing on one foot. Increasing the weight can also provide an excellent mode to improve strength.
Eventually, you will progress to a greater load with exercises such as squats. The last movements will include extension and rotations, particularly if your sport or activity requires these movements. It is important to re-introduce these movements as part of physical therapy to ensure that they are tolerated in daily activities. Cardiovascular exercise including walking is crucial to make sure that you have the necessary endurance for daily activities as well.
How to Prevent Spondylolisthesis
If you are reading this and hoping to prevent a spondylolisthesis, then you probably already have some good ideas. It is important to maintain mobility of your thoracic spine and hips to offload stress from your lumbar spine. You should also maintain strength of your core and back muscles to take stress away from the spine and passive support. Finally, pay attention to repetitive motions that may stress the area. If you are a baseball player, keep track of how many swings you take at practice and dial them back if you are noticing some pain. A temporary decrease of rotation and extension can allow you to strengthen your muscles and improve your tolerance. A thorough assessment by a medical professional can give you the best individualized ideas and plan.
As always, if you are suffering from pain, nerve symptoms (numbness, tingling, or weakness), or anything else significant, please see a healthcare provider. This blog is meant to be educational and is not a substitute for medical advice.
Hopefully you learned something about spondylolisthesis and how it is diagnosed and treated. If you want to learn more about low back injuries, check out our low back page. If you found this blog helpful, please share it with someone. We hope to continue to grow and help people better understand how our bodies move and work. If you are in the Sterling, Virginia area and would like to work with me or you have any questions, please email me at firstname.lastname@example.org or follow me on Instagram or Twitter @drdannydpt.