Why Dak Prescott's Compound Fracture May be Better than a Sprain.

For those of you who were able to stomach Dak Prescott's compound ankle fracture last Sunday, you may be thinking his career is over. But not so fast! Sometimes fractures can be less complicated than a sprain depending on the location of the ligament, its blood supply and amount of trauma. Here are three reasons a compound fracture is better than a grade 3 sprain (large tear of a ligament) in the ankle.

Bone has very good blood supply: In order for any part of our body to heal well, it must have a good blood supply. Blood is what brings nutrients and cells to help heal the injured area. Without blood, tissue or bone can become necrotic, eventually leading to the "death" of the tissue. In bones we weight bear on, especially ones like the tibia, there is a good amount of blood flow to help keep them alive, strong, and replace broken down bone. When a bone is fractured, it is imperative to relocate (or reduce) the site. This will allow bone to start the healing process on its own. In some cases, screws, plates or rods may also be needed to keep the bone aligned to help assist in the healing process. Ligaments, on the other hand, can have very poor blood supply, making them less likely to fully heal.
Reducing a fractured bone is easier: When a bone is fractured in a "clean" break, it can be relatively easy to realign. Sometimes after this realignment the bone is placed in a sling or cast. In more severe fractures, the bone can still be realigned but must be held in place with hardware such as screws, rods, plates or external fixators. Despite the use of this hardware, this procedure can still be less complicated then repairing a torn ligament. When a ligament is torn, it must be sutured back together. In some cases, if the ligament is ruptured, the fibers may not be strong enough to hold the sutures. Additionally if the ligament ruptures and "rolls" up onto itself, it may be difficult to realign and suture back together. Ligaments are also more flexible than bones. This flexibility makes it difficult to fixate. Therefore the likelihood of the sutures failing is much higher than the hardware failing on the bone.
Bone healing is stimulated by compression: The most optimal way to stimulate bone healing is applying compressive forces (weight bearing) intermittently. In bones that are mostly made to weight-bear (such as the leg bones) this type of compression can be easily achieved by walking, squatting and completely "closed chain" exercises. This makes rehabbing a fractured leg bone relatively straight forward. Conversely, when a ligament is sprained or torn, it is not so easily repaired with compressive forces. Ligaments mostly prevent excess torsional forces. Completing actives and exercises that mimic these forces can increase the risk of re-injury. Therefore many times, rehab is focused on maintaining proper joint alignment and limiting certain motions for a period of time. This in turn, can lead to more muscle atrophy, loss of proprioception and negatively effect balance. Overall, it takes bone 4 weeks to heal, whereas ligaments can take 6 weeks.

In the case of Dak's injury, a compound fracture (where the skin is broken open) surgery is emergent and required to reduce and stabilize the fracture site. Many times this traumatic injury will require hardware, either internally or externally applied, to help keep the bone aligned in the beginning phase of healing. But pretty quickly, this injury requires weightbearing, walking, strengthening, and balancing on the leg. Most people with this type of injury will make a full recovery if there are no complications with infection, bone healing, or hardware rejection. I would expect to see Dak back on the field again next season, stronger than ever!