An Overview on Dens Fracture
There are different names for the different bones in the body to identify them easily. These bones are also at risk to experience fractures. Once a bone is broken, the break is considered as a bone fracture. Despite how thick and stable the bones are, especially if they are rich in calcium phosphate, there is still a possibility that they would succumb to the force of a strong external impact. This is why injuries like comminuted fracture do happen, wherein the strong force even crush the affected bone into more than three pieces. When the feet can no longer manage the repeated impact from the weight and movement of a person, a dancers fracture could happen. Too much force applied on the feet as well can result to foot stress fracture. Brawling and hitting a hard spot would cause your knuckles to have a boxer fracture. The dens fracture is another type of injury that also deserves to be discussed.
Anatomy of Dens or Odontoid Process or Peg
The odontoid process is another name for dens. This is a part of C2 (axis) which is joined with C1 (atlas). These two parts are connected by three different joints, namely: (1) bilateral joint, (2) central atlantoaxial joint; and (3) lateral atlantoaxial joint. In terms of support for dens, there are ligaments, the dentate and the transverse, that enable the dens to have translational and rotational stability. In fact, the dens can grow closer to C1 when it is being held by the transverse ligament. Basically, dens are made up of the remnants of the body that are usually left out and have now gathered together.
You can identify a bone that is affected by dens fractures. It can be distinguished from the other parts oft the body due to the oval shape of the joint near it. This joint connects the dens to the anterior arch of the atlas. This particular bone called dens has a shape with a neck-like structure or constriction. There is also a transverse atlantal ligament which is found at the back of the neck. This holds the dens near.
Dens Fracture Classification
This is also called as the odontoid fracture, based on the other names of dens which are odontoid process and odontoid peg. There are certain common things that are observed among most of the cases of dens or C2 fracture that serve as the classification of the fracture. It should be noted that dens is still a part of the axis called C2 hence the name of the fracture in the said area. Most cervical dens fracture cases happen to those people who have fallen with severe impact and those who had vehicular accidents. It is during these cases that the body would be exposed to a strong impact that would crush the bones resulting to fractured dens. Among the risks that victims of accidents experience would be cervical spine fractures. Any fracture spinal would be dangerous because this is close to the nervous system. When not handled with great care, this dens bone fracture might get you paralyzed.
In some rare cases, dens fracture in children should be watched by parents carefully. These kids do not know much about the danger that lies ahead of them. Among all the C-spine injuries that are observed, a third of these injuries occur on the C2. Injuries on the C6 and C7 only cover half of the cases where the C2 is the part that is hurt. Thus a C2 bone breakage is one of the common dens fracture types. These broken dens bones usually happen due to rotation, extension, and flexion. Upon the damage of the C1 and C2 due to fracture injury, the case might grow worse because the cervical spine fracture is one of the most fatal types of dens fracture. In fact, first aid might no longer be really that effective in the worst cases of the spinal fracture. The idea to treat dens fracture through surgery would really be necessary when the fracture has an open wound. The fracture healing time for complex fractures would take sometime as well, especially with a surgery coming up.
Types of Dens Fractures
There are several types of odontoid fractures that are usually observed among the victims of this injury. These are type I, II, and III fractures.
Type I Dens Fracture
This is not really a common type of odontoid fracture. It is characterized by the dens being lodged at the tip of the odontoid process, just near the alar ligament. The fracture can be found in the joint near the occiput. This is a fracture that does not really need urgent medical attention because it is a stable dens injury. However, the patient runs the risk of possibly having atlanto-occipital dislocation. This kind of injury should not be attended to only when it has become worse. In some studies, only 5% of the cases of dens injury are attributed to this type of odontoid fracture. Pain would be easier to bear if medicines are taken. Type 1 dens fracture is brought about by the instability of the traction in which the fracture is being placed. Medical findings would identify this as an avulsion injury. Thus, the patient has nothing much to worry about.
Type II Dens Fracture
This is the most common type of odontoid fracture. The fractured dens is found at the base of the odontoid process right where it is connected to the body which is at the C2. Type 2 dens fracture makes up more than 60% of the cases of odontoid fractures. In some cases, the fragments of the fractured bone are displaced. They are situated in places where they should not be in. To correct this, angulation or the proper monitoring of the dens fracture type 2 injury has to be done. There is a bi-fold mechanism in this injury, being that the hyperextension is connected to the concomitant axial loading while flexion is to the concomitant axial compression. Thus, the patient of this type of dens fractures would likely have bilateral pedicle injury. Moreover, the PLL and C2 or C3 disk would also be affected. Unlike the type 1 fracture of the odontoid process, this one is considered unstable. Wedge compression is also usually associated with this type of fracture.
Type III Dens Fracture
This is around nine percent of most of the cases of odontoid fractures. A more serious type of fracture with an extreme case of displacement and angulation cases can typically be the definition of the type 3 dens fracture. This injury also has the mechanism that involves the flexion connected to the concomitant axial compression. The result of dens fracture type 3 would also be bilaterial pedicle fractures. Like in type 2, the C2 and C3 are also affected. At some point, these parts of the body would even be dislocated. The bones are no match to a really strong external impact. There is also high mortality and morbidity with this type of fracture dens.
Most cases of this odontoid fracture would have the patient feel the pain. It is also not easy to move the affected part, particularly the quadriplegia. The patient would feel unstable when supported by the spine.
Like in many other types of fractures, x-ray is necessary to see the actual break on the bone. This will allow the doctor to know what kind of dens fracture treatment is really necessary. The recovery time will also be predicted as well. The CT scan proves to be more capable of detecting fractures. An MRI scan is necessary for the evaluation of the ligaments, spinal cord, disk, and a possibility of some soft tissue injuries. All these examinations will also warn the patient about possible fracture complications and risks that need to be handled. Fracture of odontoid process is quite lethal and risky, especially the types II and III of the said the fracture.
The type I fracture’s treatment would last for six to eight weeks, using hard collar methods. This is a shorter dens fracture healing time when compared to other types of fractures. The type II fracture’s methods of treatment would be operative fixation or screws, halo immobilization for 12 to 16 weeks, and arthrodesis of the C1 and C2 bones. The type III fracture can have fracture surgery or halo immobilization.