Is it Broken or is it Fractured?
This is a common question asked of many orthopedic practitioners. The two words mean the same thing. Clinicians speak in terms of different kinds of fractures to describe how a bone is broken. Determining how a bone is fractured will help to tell what type of treatment is needed in many cases. There are several types of fractures, which are classified into two categories: Complete and Incomplete.
Incomplete Fractures
Incomplete fractures are breaks in the bone that do not go all the way through the bone. Two forms of incomplete fractures are a bucklefracture and a greenstick fracture.
Buckle fractures (also known as Torus fractures) are usually caused by a fall on an outstretched hand resulting in a wrinkle in the bone much like what happens to a drinking straw when it is bent in half. Like the straw, the bone is weaker at the level of the wrinkle and is treated with a cast to allow the bone to heal in the proper position and to protect the area from further injury.
Greenstick fractures are most often a result of a force being applied to a bone from the side. The result is a fracture much like what happens when a young tree branch is snapped and with one side only bending while the other splinters. This injury is also treated with a cast to allowing for proper healing.
Complete Fractures
Complete fractures are usually caused by a larger force and result in a complete break through the bone. Complete fractures are further classified into simple and complex fractures.
Simple fractures result in bones being broken into two pieces and are described by the way they travel through the bone. A transverse fracture goes straight across the bone. An oblique fracture travels at an angle through the bone. Lastly, a spiral fracture is at an angle that has been twisted through the bone. Most of the time these fractures can be treated with a cast alone; however, sometimes extra steps are necessary to push the two fractured pieces back together. Occasionally, surgery is needed to put the bone back together with the help of pins, screws, rods and plates.
Complex fractures (also known as Comminuted) occur when a bone is struck with a great force causing the bone to break into three or more pieces. This more commonly happens to older children and adults; although, younger children can have complex fractures as well if enough force is applied. Treatment is often similar to simple fractures.
Growth Plate Injuries
In general, children have softer bones than adults, in part because they are still growing. This makes them more likely to have fractures than sprains and strains. In order for children to grow they must have bones that are big enough and strong enough to allow them to grow. This growth happens at a place in the bone called the growth plate. Also known as the physis, a growth plate is a place near the end of children’s bones where cells are rapidly produced to make the bone longer and bigger. Since the bone is new in this area, it is also softer (weaker). Unlike adult bones, which have hardened, children’s growth plates are actually weaker than the tendons that attach muscle to bone and the ligaments that attach the bones together. This is the very reason children are have more fractures than torn muscles, tendons and ligaments. During an injury, the muscles, tendons and ligaments hold strong. This puts a large amount of the force from a traumatic event (such as a sporting injury or an automobile accident) into the growth plate resulting in a fracture.
Growth plate fractures can present in many ways. They can be displaced (when one end of the growth plate has slid out from under the other end) and non-displaced (when both ends of the fracture are in line with the bone). Displaced fractures are much easier to diagnose on x-ray and sometimes require reduction (bone realignment) and/or surgery to make sure the bone heals in the proper position. Non-displaced fractures are harder to diagnose on x-ray and require the trained hand of a medical provider to discover. With the knowledge of anatomy and through clinical training, orthopedic clinicians are able to assess non-displaced fractures by touch over the injured area.
Growth plate fractures are among the quickest fractures to heal due to the rich blood supply and healing factors to the area. Because children are still growing, they have the ability to remodel fractures faster than adults. For this reason, orthopedists are able to use more conservative treatment (casting and splinting) to treat children’s fractures in most cases.
Bone Remodeling
Children have a thick covering around their bones call periosteum. Adults have periosteum also, but as a person ages the periosteum gets thinner. In children, this thick periosteum acts as scaffolding to allow new bone to form in and around a fracture. As a fracture heals in a child, new bone forms a “callus” around the fracture site. The callus consists of bone material and acts as a re-enforcement to the fracture on the outside. Within the bone, the body also places new bone to act as “super-glue” to help stabilized the fracture on the inside.
This is similar to callus formation on the skin. If you wear shoes that rub on your heal, you get a callus at the point of greatest friction. This is your body’s way of preventing injury to your heal. A boney callus is similar in that it is the body’s way of insuring healing and preventing further injury. In other words, your body does not know if another injury will happen any time soon, but it is going to lay down more bone to decrease the chance for another fracture. Overtime, the combination of the periosteum and new bone growth, the bone is able to remodel back to its original form. This may take months to happen. Depending on the age of the child, remodeling can often prevent the need for surgery to repair fractures.
Most Common Fracture in Children
Many studies have evaluated children’s fractures to determine what is the most common fracture in children. It has been determined the wrist (distal radius and ulna) is the area most often fractured in young people. This injury is most often seen in adolescent males; however, this injury is commonly seen in all age groups and genders. In fact, more than 25 percent of all fractures present in this area.1
Fractures at the distal radius and ulna are usually treated with a short-arm cast for 4-6 weeks. Occasionally, the use of a long-arm cast is needed to help stabilize more severe wrist fractures. Rarely, the use of screws, plates and pins are used but are more common in adults than children.
References:
1. Herring J. Tachdjian’s Pediatric Orthopedics, Fourth Ed.
2. Pictures from www.eorthopod.com