Health

What problems can develop that involve the growing bone of a child with a limb deficiency or amputation?

During normal child development, excessive bone may grow around the site of the limb deficiency or amputation. Unfortunately, this normal bone growth may become uncomfortable to the child because the residual limb can no longer fit into the socket. Because of this, the excessive bone may need to be removed. Until the child stops growing the bone may reaccumulate, and repeat surgeries may be necessary.

Unfortunately, surgeries that have attempted to halt this “normal” growth have not been met with great success. One type of amputation that is not associated with this bony overgrowth is when the amputation occurs through a joint itself. This type of amputation is referred to as a disarticulation and is beneficial, since the end of the limb can tolerate more weight than an amputation through a bone.

What are the types of pediatric limb abnormalities?

In general there are two types of limb abnormalities seen in infants and children. Sixty percent of limb abnormalities occur before birth and are therefore referred to as congenital limb deficiencies. The other 40 percent result when a child is born with otherwise normal limbs but then sustains an amputation from trauma, tumor or infection.

How often will a prosthesis need to be adjusted for a growing child with a limb deficiency or amputation?

As a child grows, the prosthesis will need to be adjusted every 3-6 months, and the entire prosthesis will usually need to be replaced every 1-2 years. Therefore, it is important to be in contact with a physician or prosthetist 3-4 times a year so that the prosthesis can be adjusted appropriately. If a facility is too far away, there is a simple way to determine if the prosthesis is now too short and the lower legs are unequal. While the child stands facing you, place your hands on the child’s hips. If your hands appear to be level while resting on the child’s hips, then the limbs are probably of equal height.

Problems with a socket can be more difficult to diagnose and treat. A tip for discerning a socket problem may be the fact that the child no longer wants to wear the prosthesis or verbalizes some discomfort while wearing it. The parent may notice redness on the residual limb. Minor blisters, abrasions or occasional pimples are not cause for too much concern. Children can be quite tolerant of pain until there is a significant problem.

One way to test that the limb is fitting uniformly in the socket is to put some crayon or lipstick on the socket and then have the child don the prosthesis. Uneven pressure will show as crayon located unevenly on the residual limb. However, this test may not always identify the problem; therefore it is prudent to check periodically with the prosthetist to ensure that the socket fits properly and comfortably.

What challenges face children with shoulder disarticulations?

Maintaining appropriate suspension on the trunk may be challenging for a child with a shoulder disarticulation who requires an upper-limb prosthesis. Additionally, the child will need to be trained on operating the artificial hand and elbow and must also learn how to move the prosthetic shoulder into an appropriate position. This often means that cables as well as a series of locking joints need to be used.

For example, the child will first need to place the prosthetic elbow joint into an appropriate position by moving the opposite normal shoulder joint. Moving the opposite normal shoulder either in flexion or away from the body will cause part of the prosthetic limb to perform a certain function such as shoulder or elbow flexion. Then once the prosthetic joint is moved it can be locked for stability. The child can then manually rotate the prosthetic wrist using their normal hand into a functional position.

Finally, just as described above, the opposite normal shoulder can be moved again, but this time it produces the terminal device to open or close depending on the type of terminal device. Although all of these actions sound tedious and very daunting, many children are able to fully operate a shoulder disarticulation or above- elbow prosthesis quite well with practice.