Article Summary: Pneumatic Arm Prosthesis in Children

Attention of our readers is drawn to Dr. Ernst Marquardt's article, "Pneumatic Arm Prosthesis in Children", which appeared in the July, 1962 issue of Medizinische Klinik (Berlin). Dr. Marquardt, of the University of Heidelberg's Orthopedic Clinic, has treated and fitted a number of the "thalidomide babies" born with congenital malformations in West Germany.

Noting that many of the deformed infants have a hand or single fingers attached directly to the shoulder, Dr. Marquardt declared that prosthetic fitting is not necessary as long as the fingers can be brought up to the mouth and the child uses his hands for play. Fitting is required later when the thorax widens, particularly for the children born entirely armless or with small stubs, or for those who are unable to reach their mouths with their shoulder-connected fingers. During infancy, priority should be given to diligent exercise of the feet and the shoulder-linked fingers. In cases where there are no fingers, the shoulders must be gymnastically exercised and trained.

Fitting is initiated in accordance with the child's development, generally at the beginning of the second year. The first step is application of plastic adherency cups which are worn for brief periods. A prosthesis is then fabricated with coupled (bilateral) internal rotation of both arms utilized as a single active function. With both elbows flexed at right angles, good grasping action is achieved by using the entire palmar surface of two passive baby mitts operating against resilient resistance (see Fig. 1 ). It has been found that a small child can control this prosthesis efficiently at the age of one year and ten months (sic). Subsequently, the child is fitted with hands which can be used individually for grasp.

Case Studies

Dr. Marquardt cites a case in which the control of internal and external rotation was achieved by a single finger attached to the right shoulder. "It is very good when little fingers can be used for important prosthetic functions," he commented, "but even if this is not possible, prosthetic functions can be controlled solely by shoulder motions."

Dr. Marquardt also cited the case of an armless girl, who was treated at the Kessler Institute for Rehabilitation, West Orange, New Jersey, and issued an arm with active prehension at the age of four years. This unit was inadequate for play and independent eating. A pneumatic prosthetic hand was substituted for the hook and a pneumatic hand rotation joint for the passive hand connect. Control was achieved with the aid of two pulling valves - grasping functions were obtained by bringing forward the shoulder and the rotatory motions of the right hand by elevation of the left shoulder. The child was able to play and eat independently on the day of the modification.

A pulling valve is no longer used to control the grasping act. The present method is to apply a contact valve to a metal bow fitted to the opposite shoulder. The child controls the grasping action by bringing the shoulder forward, while hand rotation is achieved by shoulder elevation on that side (that is, one side is fitted with the plastic adherency cup and the prosthesis and the other side is utilized for control of grasp and rotation). A quadruple pressure valve for controlling elbow functions is established at the shoulder level on the prosthetic side.

Ease of Construction

The ease with which construction of a prosthesis of this type can be learned was demonstrated at the first course for the fabrication of pneumatic prostheses at the trade school for orthopedic technicians, Frankfort on the Main, April 24-28, 1962. Students fabricated four pneumatic arms during the course, including a unit for an armless five-year-old child who possessed only a tiny finger on either shoulder. The fingers had not received training of any kind but the child was able to control the prosthetic functions at the initial fitting.

Dr. Marquardt stressed the need for close cooperation between the prosthetist and the clinic. He recommended that the prosthetist fabricate the device in a "rough" (unfinished) form and then refer the child to clinical treatment. During this time, the prosthetist and the physical therapist who is training the child maintain continuous contact. The prosthesis is not completed until the training period is concluded.