An orthosis is a device applied on the exterior of the body to limit or assist motion or reduce the load on a part of the body. Many foot and ankle disorders in children can be treated with ankle foot orthoses, sometimes referred to as AFOs or braces. Any disorder that results in a muscle or ligament imbalance may cause physical or structural deformity in the foot. Abnormalities are sometimes the result of neurological problems, genetic disorders or trauma.
An AFO works by applying pressure to the structure of the foot and ankle. What makes external bracing more complex is the need to apply this pressure through the skin and its underlying tissue. The need to minimize the skin and tissue injury as a result of this pressure requires an extremely accurate fit of the brace to the child and regular adjustment. Adjustment of the AFO as the child grows is an important part of the treatment. When adjustments can no longer be made, AFOs must be replaced.
A medical diagnosis is always the first step. An orthotic evaluation is the second step, and the treatment process continues with the impression, fabrication, fitting and the follow-up.
Orthotics is taught at the college level. An additional internship and an examination by either the American -Board for Certification in Orthotics and Prosthetics (ABC) or the Board of Certification/Accreditation, International (BOC) is required before an individual is recognized as a certified orthotist. Orthotists are trained to fabricate, fit and maintain orthoses. They are experienced in examining deformity and estimating potential correction. Evaluation is an ongoing part of treatment at Kinetic. It allows us to know when modifications or adjustments are needed and when it is time for replacement. In addition, the child’s size, physical condition, secondary pathologies, cognitive abilities, age and family situation all play an important part in the design of each brace.
Fabrication of AFOs starts with making an impression of the limb. From this negative mold, a positive plaster model of the limb is made and modified. The more accurate this impression is, the easier the laboratory procedures will be. The fabrication of the orthosis can begin when modifications are completed. The proper thermoplastic material is selected and cut to the correct dimensions for forming. The type and thickness of the plastic used is based on the requirements of the individual child. This plastic is heated in an oven until it reaches its liquid state. At this time it is stretched over the model and sealed, and vacuum is applied. Vacuum is maintained until the plastic has set. After this initial set takes place, the orthosis must remain undisturbed for 24 hours to allow the stresses in the plastic to normalize (anneal). The AFO is then trimmed out, the edges of the orthosis are shaped to allow the brace to fit comfortably inside a child’s shoe or sneaker, and then they are finished by sanding and buffing to achieve a smooth edge. Once the AFO is finished, the velcro strapping system is designed, fabricated and attached. At this point the AFO is ready for fitting to the child. While AFOs look similar, each is highly individualized because of the modifications necessary to apply the precise corrective pressures each child requires.
Correcting the positions of the various parts of the foot is a complex undertaking. Because it is difficult to obtain a perfect impression from children, and because there can be day-to-day changes in tone, we expect to adjust the AFO to accommodate small, but’ important, differences between the time the impression is taken and the time of application.
Follow-up is scheduled, on an individual basis, and the amount of subsequent care required varies widely. At the very least, your child will need to be seen three times. The normal spacing of these visits is once two weeks after delivery, and twice at three month intervals. Any special requirements your child has may change this schedule.
The laboratory time required to design and produce an AFO varies with the complexity of the case. If each step goes smoothly, an AFO requires a minimum of seven hours laboratory time and two hours of direct patient time. Patients are scheduled so that laboratory time directly follows the time scheduled for taking the impression. If this time is not interrupted by emergencies, the fitting appointment follows in one to two weeks. Your child will receive an appointment for the fitting at the time of molding and casting.
Costs are a major concern for parents. To satisfy the requirements of the insurance companies that cover children’s orthotic treatment, Kinetic bills all services as a single device charge. This means that initial evaluation, the plaster cast impression, the laboratory time to make the device, the fitting of the brace and follow-up visits are billed to the insurance carrier at one time.
AFOs help to manage foot and ankle positioning in children with cerebral palsy, spina bifida, muscular dystrophy and other neurological or genetic disorders. AFOs hold the ankle in a stable position and provide a stable base of support for the lower extremities, enabling the physical or occupational therapist to facilitate improved mobility at the pelvis and trunk. AFOs, by providing a stable position for the foot and ankle, allow the child to concentrate more on the physical process of walking and less on balancing. In children with cerebral palsy, AFOs are often prescribed when a child can achieve the correct foot position during therapy, but is unable to maintain it later. AFOs also may be appropriate to prevent foot deformities, even for children who do not walk.
When your child is fitted with an AFO, you will receive written wearing instructions. Some of the points included in the instructions are: * Always wear a sock under the brace (AFO). The sock should be as high as the AFO.* A gradual break-in period is suggested. One to two hours at a time, several times per day for the first week. Gradually increase wearing tolerance to all day. It is not necessary to wear the AFO at night unless instructed to by your physician.* A larger sneaker will be needed to accommodate the AFO. Split size footwear may be needed.* When the AFO is removed, look for redness or irritation that does not disappear within 15-20 minutes.* Remember, we are realigning the structure of your child’s foot and this may cause some irritation.* Call the orthotist, if you have any questions.