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Although some of the prosthetic principles apply to both the adult and pediatric populations, pediatric patients present with some clinical considerations unique to their cohort. One clinical consideration that presents on a continual basis is growth. A prosthetist has no way of predicting a patient’s growth spurts. As a result clinicians have developed techniques to accommodate unmarked growth.

There are five clinically proven methods used to allow for growth; they are all used to increase the lifespan of the prosthetic device. These five methods include socket liners, the onion shell technique, additional socks, distal end pads, and flexible interfaces.

Socket Liners

The use of socket liners to prolong the life of the prosthetic device in the pediatric patients has become an industry standard over the past several years. Prosthetists have the option of using off-the-shelf prosthetic liners, which come in varying thicknesses, or using custom-made liners. By fitting a pediatric patient with a 9mm liner, the thickest available, the prosthetist then has the option to move to a thinner liner as the child grows. By adopting this technique, the prosthetist is only replacing the liner rather than an entire socket.

Clinicians may also elect to use custom-made liners. These liners are easily modified, inexpensive, and a simple solution to accommodating circumferential growth.

The Onion Shell Technique

The onion shell technique is a second method used to accommodate growth. Introduced to the pediatric prosthetic population in 1964, the technique was used at many child amputee clinics throughout the nation.

The onion shell technique involves the fabrication of an additional lining to the inner socket that may be removed as the socket becomes too tight. This inner socket layer is separated from the outer socket by a PVA bag, allowing for easy removal of this inner layer.

Additional Socks

The use of additional socks is a third technique for addressing unpredicted growth. In general, fitting a child with a sock ply fit is standard operating procedure. This thought process follows the same principles as that of the liner fit, although this is a more economical way of addressing growth compared to that of silicone liners. By fitting a child with a 5-ply sock fit one can then accommodate growth through the removal of sock ply. This technique, however, will not address longitudinal growth of the patient’s residuum.

Distal Pads

Distal pads are yet another technique used to address longitudinal growth. The RTV foam is an excellent silicone that can be used in the fabrication of these distal pads. The prosthetist may elect to fit a child with a ½-inch pad that accommodates distal growth as well as bony overgrowth, which is common in the acquired lower limb below-the-knee amputee patients. As the child grows the clinician then has the option to remove the pad and fabricate a thinner pad.

A child may complain of distal limb pain directly related to the bony overgrowth. To address this, a new pad can be poured, alleviating the pain by accommodating these anatomical changes.

Flexible Sockets

The final way to address growth is the use of flexible sockets. This technique has been used in child amputee clinics, and has proven to be beneficial. The benefits to this technique are the ability to adjust the socket by heatheating and stretching the socket material, and the ability to make visual diagnosis due to the socket’s transparent characteristic.

As with any design, the prosthetist has to consider the patient and his or her needs before selecting one of the five techniques. It is also noted that a child may grow more than expected resulting in the fabrication of a new prosthesis despite the incorporation of one of these techniques in the original design.