Dear Doctors: Our 16-year-old son recently broke his arm skateboarding. He had to have surgery, and now he’s in a cast. I broke my arm back when I was a boy, but all I needed was a cast. Why does a broken arm need surgery? How long does it take for that kind of break to heal?
A. Our bones are a miracle of engineering. Made up largely of collagen, a protein that provides a pliable framework, and calcium, a mineral that supplies strength and rigidity, the bones in our bodies manage to be both hard and flexible. This duality allows them to withstand surprisingly high levels of force, torque and compression.
When an outside force is too great, however, the bone will break. The type of break that occurs, and how serious it turns out to be, depends on the strength of that force, the angle or position at which it meets the bone and the health of the bone itself.
Fractures fall into two main categories — closed and open. In a closed fracture, also referred to as a simple fracture, the bone is broken but has not penetrated the surrounding muscle or skin. When someone has an open fracture, sometimes also known as a compound fracture, it means there is an open wound at or near the site of the break. This is usually because either the bone or bone fragments have pierced the flesh and penetrated the skin.
Diagnosis begins with a physical examination. X-rays are used to visualize the type of break the person has sustained and to pinpoint its location.
For a broken bone to heal properly, it must be appropriately aligned. Depending on the type of fracture, this can require the physician to reposition, or set, the broken ends of the bone. This is a procedure known as reduction. In order to preserve proper alignment as the bone heals, the fractured limb must be immobilized. A temporary splint is typically used until the initial swelling, which commonly occurs after a fracture, has gone down. This can take up to a week or more. After that, the patient is fitted with a sturdier, more permanent device. Depending on the type and severity of the break, this may be a sling, a brace or a cast.
The fact that your childhood fracture required only a cast suggests that the broken ends of the bone lined up easily. This allowed your doctor to successfully set the bone and use a cast to immobilize it. But in more complex cases, where a bone is broken in multiple places, or in a manner that compromises its future structural integrity, surgery may be required. This entails the use of screws, rods or plates to realign, rebuild and support the bone. Recovery time varies, but it typically takes about eight weeks for the break to heal. After the injury has healed and the cast has come off, physical therapy is often needed. It’s important not to skip this step, as it will help your son to regain strength and range of motion.
Eve Glazier, M.D., MBA, and Elizabeth Ko, M.D., are internists at UCLA Health.
