Overview of spinal anatomy

The spine is one of the main supporting structures of our body that provides us with structure and mobility. The spine is made up of three groups of vertebrae: the cervical vertebrae, which make up our neck, the thoracic vertebrae, which make up our upper/mid back, and the lumbar vertebrae, which make up the lower back. The function of our spine is to protect our spinal cord and the nerves that exit from it, supplying the whole body.¹

Anatomy of the transverse process

Location: lateral projections off each vertebra

Now, when we break down each vertebra's specific anatomy, there are a few key structures we should pay attention to. If you were to touch your back, you could likely feel some bony parts running up and down your spine; those are the spinous processes, which function to protect your spine. On either side of them in a T-shaped formation are the transverse processes. For this article, today we will be focusing on the transverse process and injuries that can occur here. 

Figure 1: This image shows the anatomy of the spinal column as well as the different parts of each vertebra. The transverse process will be the focus of today's article.²

What is the purpose of the transverse process? 

The transverse processes are connected by ligaments traversing up and down the spine. Not only do they help stabilise or keep us upright, but they also allow us to bend, twist, and move.³ Specifically, without those transverse processes, you wouldn’t be able to do all those dance moves you're so proud of (and which some of us really may not want to see). 

Causes of transverse process fractures

A transverse process fracture, like many fractures, occurs due to high-velocity traumas such as car accidents, but often in sports injuries as well. Studies have shown that motor vehicle accidents take the lead in causes for admission, at 44.7%.⁴ However, the thing that truly causes these fractures is injuries where you can anticipate the impact. For example, when an accident is about to occur and your muscles tense up, this is when you are most prone to sustaining a fracture to the transverse process. Sports injuries often cause these fractures, as well as times the athlete is tensed up or twisting in a certain motion when an unexpected impact occurs.³ Thus, in both of these common scenarios, the muscles attached to the transverse processes are tense, and when the impact occurs, they rip at the transverse process, causing a fracture. 

Something important for clinicians to consider is that, typically, the force required to cause a fracture of the transverse process is also a force that could result in many other injuries or traumas. Thus, in the setting of a transverse process fracture, it is important to investigate thoroughly for other causes as well. Be sure to notify your healthcare provider if you develop symptoms of numbness or tingling, weakness, incontinence (which is another term for loss of control of your bowel or bladder), blood in your urine or stool, shortness of breath or chest pain, or significant swelling of one or both extremities.³
Transverse process fractures most commonly occur in the upper region of the lumbar spine. While it is most common there, when these fractures occur in the cervical spine, it can sometimes be a bit more dangerous if they involve the transverse foramen due to the risk of vertebral artery dissection, which is a rare but life-threatening condition. 

Clinical presentation

When looking at pain in the setting of a spinal injury, one of the most important things to know is where exactly the pain is. Pain that radiates, meaning it shoots out from the spine and travels elsewhere, like wrapping around the torso or shooting down the legs, typically signals nerve pain. Pain that is within an inch or two of the spinal column is often a muscular pain. However, pain directly in the centre or near the spinous processes, the superficial structures we mentioned earlier in this article, can often signify a fracture of the vertebrae. 

One of the main signs of a transverse fracture is tenderness in the centre of the back close to the spinous processes. There may also be swelling or bruising, or difficulty moving/stiffness. You may also notice some muscle tightness/spasming or radiation, suggesting nerve injury; however, the main symptoms we are focusing on in the setting of a fracture are local tenderness. 

Diagnostic approach

The most common place someone may be diagnosed with one of these fractures is at an urgent care or an emergency room. The first diagnostic test used in the majority of cases would be an X-ray. In the setting of a more complex fracture, a fracture that is hard to see, or one that the provider believes is between the two studies, a CT scan would be considered the “gold standard”. 

Treatment and management

One of the biggest difficulties in treating these fractures is that, unlike a fracture of your arms and legs, we cannot cast/completely immobilise the spine. However, a back brace is a great way to immobilise the spine as much as possible to speed up the rate of healing. It's also important to lie flat and try to avoid sitting for prolonged periods.³ Your medical provider will likely prescribe you different medications to help with pain control as well as muscle spasms, and the healing time is roughly 4-8 weeks. Typically, after this time, if the patient is still struggling with chronic pain, they will be reassessed, and if the fracture is not healing appropriately, then surgery may be considered.³ As a patient, you will be cleared incrementally to lift objects weighing more than 5- 15 lbs, and eventually, you might even be enrolled in physical therapy.³

Clinical implications

Injuries are typically considered minor in a setting where there is one, isolated fracture of a transverse process. However, if there are multiple transverse process fractures, it can be suggestive of a much more serious problem. These transverse processes and the ligaments connecting them all help keep the spine stable and in alignment; however, if there are multiple levels of fractures, it can cause subluxation, creating an unstable fracture.⁵ In certain situations, these unstable fractures can be extremely dangerous and may require surgery. In a more complex or unstable fracture, MRI might be a good option to obtain a comprehensive picture of not only the fracture but some of the surrounding ligaments as well.⁵

Summary

To conclude, a transverse process fracture is a fracture that can occur within your spine at any vertebra level, however, particularly due to high-velocity trauma. When there is one fracture in isolation, it is typically a stable and minor injury, however, multiple fractures may suggest a more serious trauma unrelated to the spine, or could cause concern for instability of the spine. It is important that if you have an injury to your spine that you seek immediate medical attention and listen closely to your healthcare provider's suggestions to obtain the best outcome. A lot of times, the studies needed to evaluate these types of fractures can result in incidental findings that help us evaluate and improve your overall health. In simple cases, healing is gradual; however, similar to other types of fractures, most people can expect to make a full and simple recovery.