The Functional Use of Phocomelic and Digital Appendages


With the development of motorized equipment for upper-limb prostheses, we, as clinicians, have been finding more constructive and functional uses for congenital phocomelic and digital appendages. In previous years their potential value often was not appreciated. They were considered useless, and the digits often were surgically removed for cosmesis or for reasons of prosthetic fit. Their possible growth and function were not considered. The phocomelic hand fared better since its value was often demonstrated early by the child's involving it in purposeful activities.

The tendency at upper-limb clinics was to fit all patients with prostheses, ignoring these appendages even when they were retained. The end result was prosthesis rejection. The children had the common sense to realize that they often could be more functionally independent using the mobile residual ray or hand with intact sensation rather than the rigid, insensitive prosthetic hook or hand.

This article will present the case histories of six of our young congenital-amputee children and will demonstrate how their appendages were used to facilitate the functional independence of the child. In some instances, prosthetic failure was necessary before a true appreciation of their value was achieved. In others, the functional prosthetic result was enhanced by taking advantage of the dexterity and sensitivity of the appendage.

Case Report 1

M.F. is diagnosed as having a right intercalary longitudinal deficiency with one ray. The X-ray report ( Figure 1 ) describes "...a humerus fused with what appears to be a residual ulna with a finger having three phalanges and four wrist ossification centers." Now age 5 ( Figure 2 ), M.F. was first seen in our child-amputee clinic at age 3 and 1/2. At that time we prescribed a right below-elbow prosthesis with an external elbow-lock mechanism but modified with an opening into the forearm socket to accommodate the finger. This allowed the digit to aid in flexing the elbow ( Figure 3 ). The patient quickly grasped the concept of elbow lock/unlock using this digit, and she now has also developed strength enough in the digit to maintain the elbow flexed without the need to activate an elbow lock. She has developed this joint into a functional elbow mechanism, thus reducing her mechanical prosthetic requirements from an above-elbow to a below-elbow type.

Case Report 2

J.U. has been diagnosed as left phocomelia. X-rays were taken and revealed, ". . . congenital absence of the humerus, with limb bud which appears to be a thumb, terminal middle and proximal phalanges and part of a metacarpal bone. The scapula and clavicle are intact ( Figure 4 )."

Now 8 years old ( Figure 5 ), J.U. was first examined at our child-amputee clinic at 10 months of age, and the recommendations were to instruct the mother in strengthening exercises for this appendage. No prosthesis was prescribed at that time.

The patient received his functional prosthesis at age 1 year and 10 months. This was a shoulder-disarticulation type containing a chest strap and an internal-locking elbow unit with a strap to he controlled manually. At age 6 his standard elbow unit was replaced with the Variety Village motorized elbow. His digit was used to activate the elbow by applying pressure on buttons located inside the shoulder cap.

The following summer (July 1975) he was provided with an experimental elbow, the "motor-lock elbow" developed at New York University and presently being field-tested by children like J.U. The microswitches were relocated to enable him to use his appendage to activate the elbow ( Figure 6 ). This modification has proved very satisfactory.

Case Report 3

A.O., who is 17 years old ( Figure 7 ), has been known to us since he was 11 months old. He has a right longitudinal intercalary deficiency. The X-ray report describes "....slight deformity of the scapula; absence of the humerus; part of the radius articulating with the glenoid; a mass of carpal bones with four metacarpal bones forming three fingers and a thumb( Figure 8 )."

The mother reported that A.O. used this partial hand for holding objects, so it was decided to postpone prosthetic fitting initially. At age 5 he was given a right above-elbow prosthesis with outside elbow lock activated by use of a chest strap. The terminal device was controlled by the usual method humeral flexion, scapula abduction. He used the normal shoulder since he lacked sufficient strength and range of motion on the amputated side. Activating the elbow lock proved very troublesome. His latest prosthesis was designed to accommodate the residual hand, allowing it to grasp and pull a loop ( Figure 9 ), thereby locking or unlocking the elbow unit. This design has proved to be successful and has remained essentially unchanged with the exception of replacing the external elbow lock with an internal elbow-locking unit and turntable. He operates his prosthesis with greater ease and is, therefore, more willing to wear it for functional activities.

Case Report 4

M.C., age 9, is diagnosed as having bilateral phocomelia of the upper limbs. The X-ray report describes, ". . . residual bony components articulating with the shoulder and wrist with four fingers present and absence of the thumb on the left. The partial hand on the right also has four fingers but with fusion of the two middle metacarpals ( Figure 10-A and Figure 10-B ).

He also has scoliosis of the thoracic spine with convexity to the right with increased tilt to the left."

M.C. was followed regularly at clinic, but a prescription for upper-limb prostheses was withheld. He was a hyperkinetic child and was generally unmanageable, both at home and in therapy. Our judgment was that he would not tolerate a prosthesis in his early years.

At 8 years of age, M.C. finally received a right shoulder-disarticulation type prosthesis with an internal-locking elbow controlled by a pull switch which he could operate with his partial hand. M.C. was evaluated in Occupational Therapy but functioned better with the left (longer) nonprosthetic side. He had a grasp of 2.7 kg (6 lbs.) and 2 kg (4 and 1/2 lbs.) of lateral pinch between the index and middle fingers. The right limb was less functional with or without the prosthesis. M.C. was last seen in clinic in April 1976. He had discontinued using his prosthesis (he is presently 9 years old) ( Figure 11 ). His mother states that he is now independent in all aspects of self-care except buttoning and zipping his trousers and wiping after toileting. He will again be seen in Occupational Therapy to solve these self-care problems without the use of prostheses. Further attempts at prosthetic fitting will not be made, since he obviously functions better and more independently without them. However, he has been scheduled for evaluation in our hand clinic to investigate the possibility of developing one ray into a thumb to improve the pinch mechanism on the left.

Case Report 5

Two-year-old M.C. has bilateral intercalary deficiencies, transverse, with the humerus present on both sides; on each side there is a rudimentary finger with three joints ( Figure 12 ).

When M.C. was seen initially at 5 months of age, bilateral preflexed sockets with passive mitts were prescribed. He was fitted with these prostheses at age 8 months, and was seen three months later for a follow-up evaluation. As one could guess, the child rejected the prostheses. He functioned more effectively without them. The parents were instructed to discontinue their use, and he was given a universal cuff to encourage unilateral use, especially for feeding. M.C. has to use the digits simultaneously for grasping objects, and the cuff allowed unilateral activities for the first time. However, he rejected the cuff device as he had the prostheses.

Most recently, an opposition-post device has been prescribed. It consists of a harness (we felt this was necessary for this young child to prevent rotation of the device) and an open socket which will encase the arm, with a projection which he will be able to oppose. He will not be restricted in circumduction of this finger nor will the device restrict the active flexion and radial deviation he has.

We are hopeful that the patient will accept this partial device, since it will provide him with a unilateral pinch mechanism. The child is older now and is more interested in a device. He is more aware of his problems in grasping and manipulating objects.

Case Report 6

D.G., now 18 years old ( Figure 13 ), is classified as having bilateral phocomelia at the shoulders. The X-rays revealed no humerus present, and underdeveloped radius and ulna bilaterally with two syndactylized digits on the left and one on the right. He also has foreshortening of the left femur.

When D.G. was first evaluated in our clinic at age 5 (April 1958), we found that he was accustomed to receiving help and had not developed total independence using his feet. He was being fed and dressed by a very "loving" grandmother. She was encouraged to allow him to function independently with his feet.

He was eventually fitted with a right shoulder-disarticulation type prosthesis with an elbow lock with chin nudge, Dorrance 12P hook, two chest straps, and a perineal strap for terminal-device control. He was trained in its use and was encouraged to use his feet for self-care.

At age 8 he was fitted bilaterally with prototype AIPR (American Institute for Prosthetic Research) C02-activated prostheses. He needed to coordinate a variety of motions to activate the elbows and terminal device. There were button valves located within the shoulder cap as well as rocker-type valves located on the outside of the shoulder cap to he activated by his phocomelic digits.

He has since been fitted bilaterally with VA electric-elbow units which he controls with his appendages by applying pressure to buttons located on the lateral sides of each shoulder-cap unit ( Figure 14 ). He has perineal straps bilaterally to control terminal-device operation.

He now is completely independent in self-care using his feet, and he uses his prostheses primarily for cosmetic purposes.


Six cases of congenital-amputee children are presented to show the varied uses of their residual phocomelic and digital appendages. We have, as have so many clinics, made the mistake of overfItting some children only to learn from them the limitations of the prostheses and the value of residual digits to the patient when these digits are allowed to function freely. There is absolutely no substitute for the sensory feedback that only the true appendage can provide. There is nothing in prosthetics as yet to substitute for this.

In other cases we have been able to increase the functional capacity of the patient by incorporating motorized equipment in the prosthesis. The child operates the device by pressing switches located at sites readily accessible to the vestigial hand or finger. We have thus been able to conserve the shoulder and/or trunk motions for the operation of the terminal device rather than reducing function by requiring these motions to operate both the elbow and the terminal device.

Amputation of residual partial or complete digits should not be performed without serious evaluation. The future ability to use these digits is not often fully appreciated at an early age. The initial prosthesis can be built around the digit, conserving it for future use for the functional advantage of the patient.

Do not burden the patient with useless prostheses simply because routine practice and custom demand it. Consider each case individually. In the shoulder disarticulation and bilateral phocomelia, encouragement should be given to attain independence in the activities of daily living using the feet, with the prostheses playing the lesser functional role which they deserve.

Prescribe with vision and with an understanding of the patients and their needs. Do not ignore the patient's insight into the problem. Remember that the main purpose of an amputee clinic is to help the patient functionally and not necessarily to prescribe prostheses.

We must take advantage of all that the patient has at his command and then add to that judiciously to achieve the best functional results.