What is Hangman’s Fractures?
A Hangman’s fracture refers to a specific type of neck injury that happens when the second cervical vertebrae (known as C2) slips forward due to broken parts on both sides of the vertebrae. This kind of injury was first mentioned in 1866, but it was only given the name “Hangman’s fracture” in 1965. It is the second most frequent type of injury that involves the C2 vertebrae, coming only after “odontoid fractures”. Hangman’s fractures account for about 4-20% of all neck fractures.
In terms of anatomy, there’s a principle known as “Steele’s rule of thirds” which divides the cross-sectional area of the first cervical vertebrae (the atlas) into three equal parts: the dens (a projection on the C2 vertebrae), space, and the spinal cord. Because there’s more space for the spinal cord at this level, people with a Hangman’s fracture don’t usually experience nerve damage.
What Causes Hangman’s Fractures?
The term “hangman’s fracture” was first used in 1965. Even though the name suggests that this type of fracture happens from the neck being stretched and extended too far, like in a judicial hanging, that’s not usually how it occurs. Instead, it most often happens when the neck is forcefully pushed backward and then bears a heavy weight or load. This is often seen in car accidents, diving incidents, or contact sports.
Risk Factors and Frequency for Hangman’s Fractures
Fractures in the cervical spine, which is located in the neck area, occur in 1% to 3% of all trauma cases. Among these, 9% to 18% are fractures of the C2 vertebra, the second bone in the cervical spine. As per a Swedish study, the cases of C2 fractures doubled from 1997 to 2014. Specifically, fractures of the odontoid process, a part of the C2 vertebra, are very common. They account for 35% to 78% of all C2 fractures. This fraction rises to 89% for patients above 70 years old. Hangman’s fractures, another type of C2 fracture, make up 11% to 25% of all C2 fractures. In a study of 58 people, the average age was just over 62 years, with slightly more women than men. The leading cause for these fractures was car accidents.
- 1% to 3% of all trauma cases involve cervical spine fractures.
- 9% to 18% of these fractures involve the C2 vertebra, the second bone in the neck.
- The number of C2 fractures has seen a double increase in Sweden from 1997 to 2014.
- Fractures of the odontoid process, a part of the C2 vertebra, account for 35% to 78% of all C2 fractures.
- Among patients over 70 years old, 89% of C2 fractures are of the odontoid process.
- 11% to 25% of C2 fractures are hangman’s fractures, another type of C2 fracture.
- In a group of 58 people, the average age was 62, and women were slightly more common than men.
- Car accidents were the most common cause of these fractures.
Signs and Symptoms of Hangman’s Fractures
Recognizing that not only car accidents and severe falls, but also less severe impacts and trauma can cause serious harm, especially in older people, is very important. Certain conditions make people more likely to experience fractures. These include having weak bones due to osteoporosis, a large number of cancer cells that have spread to the bones, or low vitamin D levels. During a physical examination, doctors may find that you have pain when they touch the back part of your neck. Also, nerve damage may be present, causing symptoms like pain that radiates down your arm or weak or numb areas on your body. More severe spine-related complications might be observed. Injuries to the vessels supplying your brain might cause abnormalities in the function of the small, rear part of your brain. All patients should be thoroughly checked for seek any sign of nerve damage, including a review of the nerves controlling the senses and movements as well as the tone of the rectum.
Testing for Hangman’s Fractures
To prepare for surgery, doctors typically run lab tests to check various aspects of your overall health. They check your hemoglobin, hematocrit, PT/PTT, INR, and platelet counts as these are needed during operative interventions.
To examine problems in the cervical spine, x-rays are often used. X-rays provide limited information but they are very essential. Good quality x-ray images are needed from the base of the skull to the first thoracic vertebra. The different views needed are lateral (from the side), anteroposterior (from front to back) and an open-mouth odontoid view which focuses on the second cervical vertebra. Combining these x-rays can help identify about 93% of cervical spine injuries. X-rays are excellent for checking the alignment of the spine at the time of injury, after surgery, and for long-term follow-up.
CT scans are largely used too. They are great for understanding the cause of a fracture and ruling out injuries, particularly for the second cervical vertebra. If there’s a high suspicion of an injury, a CT scan is recommended even if x-rays show nothing abnormal. But keep in mind, CT scans do not directly evaluate the spinal cord, soft tissue, or ligaments. Also, to get complete images, CT scans with thin slices are necessary.
Another imaging technique commonly used for diagnosing spine injuries is MRI. It is extremely useful for examining soft tissues like ligaments, disc space, the spinal cord or nerve roots. It provides more detailed information especially about the exact nature of the fracture. MRI imaging uses a T2 signal and STIR changes within the dens, ligaments, or soft tissue to do this. Unlike x-rays and CT scans, MRI is safer and does not involve radiation.
MRI is also used to measure the angle and forward movement of the second and third cervical vertebrae. It identifies any teardrop fractures involving the second or third vertebrae, or any injury to the disc or ligaments in between these two vertebrae.
Vascular imaging is sometimes needed as the artery in the neck that supply blood to the brain can be at risk of injury in the vertebrae fractures. In one study, 15% of cases with fractures had arterial injuries, especially those with type-III odontoid fractures. Untreated artery injury can lead to stroke in about 24% of cases. CT angiography, which examines the vessels, can be added to the regular CT imaging provided kidney function is considered. At present, MR angiography is not the sole imaging method for examining artery injury. Nevertheless, the first-line investigation using percutaneous angiography is overly aggressive.
Treatment Options for Hangman’s Fractures
Treatment options for Hangman’s fractures can be divided into non-surgical and surgical procedures.
Non-surgical Treatments
The first step of treatment typically involves the use of a rigid neck brace. Bodily fusion (the healing process that merges fractured bones) occurs in approximately 90% of these fractures just by immobilizing the neck alone. The types of hangman’s fractures known as Levine-Edwards type I and type II can usually be treated without surgery, while Levine type IIa and type III fractures usually require surgery.
Another option is a halo-vest, a type of external brace, which has a high success rate for reduction and fusion. However, these devices are usually not recommended for older patients as they may be uncomfortable. Depending on the severity and type of fracture, external braces should be worn for 8 to 14 weeks.
However, non-surgical treatments have a higher risk of nonunion (bones failing to grow together), especially for more complex fractures. For example, the fusion rate for Levine-Edward’s type I fractures using conservative treatment is almost 100%, but this decreases to around 30% for type III fractures. These treatments are also time-consuming and should be weighed against the increased risk of complications and mortality in older patients.
Surgical Treatments
Surgery may be necessary for more severe or complex fractures, those that cannot be addressed with external immobilization, or in cases where non-surgical methods haven’t achieved bone union.
The goal of surgery is to stabilize the neck while preserving as much neck movement as possible. This is important as abnormal angulation and improper fracture reduction can increase the risk for neck pain, nonunion or implant failure.
Internal fixation, a surgical method which involves the use of implants to secure the fracture, can be performed from both the front (anterior) or the back (posterior) of the spine and also by combining both approaches. The technique used depends on several considerations such as surgeon’s experience, the type of fracture, the location of the vertebral artery, the patient’s overall health and bone quality.
For an anterior approach, the fusion of the second and third cervical vertebrae is performed, which has the benefit of preserving the movement of the first cervical vertebra.
In a posterior approach, screws are placed in different parts of the 1st, 2nd and possibly the 3rd cervical vertebrae. This method requires a careful review by a neurosurgeon or orthopedic spine surgeon and vascular imaging to clearly define the location of the vertebral artery.
Finally, the kind of injury (flexion/extension) and the type of fracture can dictate whether an anterior or posterior fixation or both are required. Moreover, advancements in medical technology such as Robot-assisted methods and intra-operative navigation systems may improve the accuracy of screw placements, therefore minimizing potential complications.
Despite the complexities associated with Hangman’s fractures, patients generally fare well, with low rates of mortality and neurological complications.
What else can Hangman’s Fractures be?
Other conditions that may appear to be similar include pseudosubluxation, which typically affects the second and third vertebrae in the neck, and the Mach effect.
What to expect with Hangman’s Fractures
Repairing a broken bone can result in full recovery with a promising long-term outlook. Some cases may require the second and third bones in the neck (C2 and C3 vertebrae) to be joined together, a procedure known as fusion. A method through the back side for this fusion surgery has shown excellent results for specific three-part fractures.
In a study of over 30 people with a specific kind of neck fracture known as a hangman’s fracture, researchers found that 85 percent of patients were completely recovered within a year.
Possible Complications When Diagnosed with Hangman’s Fractures
The Hangman’s fracture, a specific type of neck fracture, can lead to several complications:
- Formation of an abnormal connection between the vertebral artery and a vein (also known as Vertebral artery arteriovenous fistula)
- Blockage or tearing of the vertebral artery
- A condition called Brown-Sequard syndrome, which affects your ability to sense pain and temperature
- Concurrent injuries to the spinal cord, particularly in certain types of fractures
There can also be complications from the various ways this type of fracture is treated:
- Difficulty swallowing after surgery (known as post-operative dysphagia); this happens in about 22.6% of people in the first week and 9.7% after 3 months. The risk is higher with a specific type of surgery and can be minimized with certain implants.
- Changes to your voice after surgery (known as post-operative dysphonia); this happens in about 24.5% of people in the first week and 3.8% after 3 months.
- Injury to the vertebral artery during surgery
- Complications from a halo brace, such as infections at the pin site, loosening of the pins, and restricted neck movements.
Preventing Hangman’s Fractures
Patients should be aware that in most situations, surgery is not necessary. Typically, they might need to use a neck collar to restrict movement, helping the injury to heal and avoiding further harm. Often, a method known as halo immobilization is used.
In rarer cases, surgery might be required. It’s crucial for patients to understand every aspect of this procedure. They should be comforted by the high success rate of recovery after the surgery, as mentioned earlier. Meanwhile, it’s equally important for them to have a realistic understanding of the recovery period, which could stretch up to a year.
