Avoiding Complications From Cast Immobilization
Today's orthopedic surgeons don't use cast immobilization as often as they used to. Newer surgical techniques have made it possible to repair bone fractures using metal plates, rods, screws, and wires.
When casting materials are used, care must be taken to avoid problems and complications. In this article, surgeons are reminded of the many precautions required in treating patients with cast immobilization.
First, beware of high-risk patients. These include anyone who can't communicate or talk, patients who are in a coma, and very young or developmentally delayed patients.
Anyone with decreased or abnormal sensation must be watched carefully. Children and adults with spasticity are also at increased risk for problems, especially pressure sores.
Both plaster and fiberglass materials are used for casts. The pros and cons of these materials are reviewed in detail. Plaster is less expensive and easier to mold. But it is heavier and not water resistant. Heat is generated when the plaster sets up. Patients can get burned during the process.
Fiberglass materials are lightweight but strong. There isn't as much ability to mold the cast to the patient. It is possible to bathe and even swim with these casts. A special waterproof liner must be used. Burns are less likely and X-rays show up better with fiberglass casts.
The surgeon decides which type of material to use with each patient. Type of injury and the age and needs of the patient are considered. The length of time the cast is going to be used is also important.
When serial casts are used, plaster is usually preferred. Serial casts are often used with infants who have clubfoot. The foot is moved as close to the normal position as possible and held in place by a cast. At the end of a short time, the cast is removed. The foot is aligned again and recast. This process is repeated until the deformity is corrected.
Tips for applying the cast are provided. Casting techniques for a well-molded cast that doesn't irritate the soft tissues are also offered. Safety of the patient is the top priority. The person applying the cast must be patient with the process.
For example, the right water temperature must be used with plaster materials. Using a warmer temp to speed up the setting time is not advised. And the plaster must set or cure before the patient's limb can be placed on a support frame or pillow.
There are many details to pay attention to during the casting process. Just the right amount of tension is needed to unroll fiberglass materials. Just the right amount of padding must be used to avoid pressure sores. Care must be taken to avoid imprints in the cast while it is setting up.
The authors offer many, many tips for proper casting technique. Risks and ways to avoid complications are also reviewed. Once the cast is applied, the patient must be monitored for problems. Any complaint should be attended to. Pain, swelling, or numbness are red flag symptoms.
The final step is cast removal. This requires equal care and attention. An oscillating saw is usually used to cut the cast material. Saw burns can occur leaving unsightly scars. If the cast is thick and the saw blade is dull, enough heat can be generated to cause a skin burn.
There is a trend toward removable splinting to avoid some of these complications with fixed casts. Taking the splint off as directed by the surgeon allows the patient or family to inspect the limb.
Some patients are better candidates than others for this type of treatment. The surgeon takes all the risk factors into consideration when deciding the best way to properly immobilize a limb for complete healing.
Matthew Halanski, MD, and Kenneth J. Noonan, MD. Cast and Splint Immobilization: Complications. In Journal of the American Academy of Orthopaedic Surgeons. January 2008. Vol. 16. No. 1. Pp. 30-40.