Pollicisation in cases of radial club hand

POLLICISATION IN CASES OF RADIAL CLUB HAND By STEWARTH. HARRISON,F.R.C.S., L.D.S.R.C.S. Department of Plastic Surgery, Wexham Park Hospital, Slough, and The Mount Vernon Centre of Plastic Surgery THE pattern of congenital deformity said to be caused by the drug thalidomide is well known and varies in severity from phocomelia to vestigial digits. The agenesis of the upper limb is predominantly on the radial side. An absent radius will produce the deformity of radial club han& and adactyly is radial rather than ulnar. A vestigial digit frequently replaces the thumb. The deformity is not confined to the bones ; limited flexion of the fingers is common and the degree of limitation becomes progressively worse towards the radial side so that it is not uncommon to find that the little finger is the only normally functioning digit. The loss of finger movement is associated with poor tendon development. Subluxation of the shoulder joint and limited flexion of the elbow may be associated with radial club hand. Functional Assessment.--Primarily the hand must reach the mouth. I f the elbow is stiff this function may only be possible if the shoulder is dislocating and is facilitated by the radial club hand position. It is evident that correction of the radial club hand position might diminish the child's ability to reach the mouth and this should be taken into consideration when assessing corrective surgery. On reaching the mouth the child may present either the dorsal or the volar aspect of the hand. Similarly, in picking up objects the dorsal aspect of the fingers is used particularly in radial club hand deformity. Alteration of this function to volar prehension would necessitate a major reconstruction at wrist level and would involve the child in a difficult and prolonged process of re-orientation handicapped by limited digital movement. In the less severe degrees of deformity where prehension is volar and either a vestigial thumb is present or the thumb totally absent, the adjacent digit tends to abduct in an attempt to adopt a position of thumb-like opposition. This type of case is suitable for pollicisation of the radial digit. The absence of thenar muscles, however, necessitates the use of an opposition transplant not only for opposition but also to prevent the tendency of the extensors and flexors to derotate the pollicised digit. Treatment.--Vestigial digits on the radial side of the hand have been used as opposition posts but are otherwise useless. In view of the importance of the thumb in the overall function of the hand, it is desirable to create a digit which is functional and for this purpose a normal or nearly normal digit is required. This paper presents two methods of pollicisation. For the less severe degrees of deformity, pollicisation on the radial side is recommended while in the established radial club hand deformity, pollicisation on the ulnar side is recommended as a possible alternative. Pollicisation on the Radial Side (Case I).--Figures I to 3 show a bilateral deformity in a child aged 6 years. On the right side there is a radial club hand deformity with four fingers and a vestigial thumb remnant. On the left side the wrist is normal ; there are four fingers and a vestigial radial remnant. There is some limitation of flexion of the radial digit but, on the whole, function is good. The child could pick up small objects 192

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using the volar aspect of the hand and it was evident that the radial digit was attempting to establish a position of abduction. Pollicisation was performed on the left hand by transfer of the radial digit. At operation the vestigial remnant was discarded and an incision made around the metacarpophalangeal joint of the adjacent digit (Fig. 4). A flap was elevated from the dorsum to line the cleft. After dissection of the neurovascular pedicle, the neck of the metacarpal was divided. A slot was cut in the base of the metacarpal and the neck of the metacarpal wired into the slot so that the digit adopted a position of abduction and opposition. Figure 5 shows the method of fixation. In the absence of any thenar muscles it was necessary to use an opposition transplant. The tendon of choice is normally the sublimis of the same finger as a thumb does not require two flexor tendons, but in this case only one flexor tendon was present and it was necessary to look for a substitute. The flexor tendon to the vestigial remnant was identified. This was presented in the forearm, passed through a loop in the flexor carpi ulnaris and after crossing the palm diagonally was inserted through a drill hole in the neck of the proximal phalanx. The hand was immobilised in plaster of Paris for four weeks and the end-result is shown in Figures 6 to 8. The pollicised digit functions very like a normal thumb and considerable improvement has been obtained. The child can now pick up small objects between the thumb and adjacent finger and a pen can be held normally. A request has been made for a similar procedure to be performed on the other hand. For this type of case there is little doubt of the justification for this procedure, but in those cases with radial club hand associated with deformities of the elbow and shoulder in which correction of the wrist deformity might not materially improve function, particularly where the little finger is the only normal functioning digit, consideration should be given to re-establishing function on the ulnar border of the hand by creating thumb function in the little finger. Pollicisation on the Ulnar Side (Case 2).--Figure 9 shows the bilateral deformity in a child aged 6 years. Both shoulders were dislocating, due to agenesis of the head of the humerus, movement at the elbow joints was limited and a severe radial club hand deformity was present on both sides. On the right side there was a vestigial thumb remnant and four fingers. Movement was limited in the radial three fingers, with flexion deformity at the proximal interphalangeal joints. The little finger had nearly normal function and was the predominantly functional digit. There was insufficient function in the radial digits to justify an attempt to re-establish function on this side of the hand, and it was evident that the child was using the ulnar digits in preference to the radial. Furthermore, the radial side of the hand could not be used effectively with the existing wrist deformity. Even if the latter was corrected, it was questionable whether an improvement in function would be gained, and it is possible that such a procedure might have resulted in a loss. It was decided, therefore, to attempt a reconstruction on the ulnar side of the hand by converting the little finger to thumb function in opposition to the ring finger, which would substitute for an index. At operation an incision was made around the metacarpophalangeal joint of the right little finger and a flap was elevated from the dorsum of the hand based on the ulnar border (Figs. IO and II). The incision around the base of the finger was extended into the palm and the neurovascular bundles were exposed. The intermetacarpal artery was ligated and divided. The nerve was split proximally. The interosseous muscle was separated and the metacarpal divided just proximal to the neck. A drill hole was made just distal to the line of section. A slot was cut in the base of the metacarpal to receive the cut distal end of the metacarpal, and the junction made fast with a wire (Fig. 12). The extensor tendon was dissected into the forearm and freed from its attachment so that it could be displaced medially and slightly anterior to the head of the ulna (Fig 13). This manoeuvre altered the direction of pull so that extension was

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FIG. I

FIG. 2

FIGS. I to 3 Case I. C h i l d aged 6 years. O n t h e r i g h t side t h e r e is a radial club h a n d w i t h four fingers a n d a vcs~.igial t h u m b . O n t h e left side t h e w r i s t is n o r m a l a n d t h e digital c o m p l e m e n t similar to t h e right.

Fro. 3

P O L L I C I S A T I O N IN CASES OF RADIAL CLUB HAND

FIG. 4

FIG. 5

Fig. 4 . - - S k i n incisions. T h e vestigial t h u m b was discarded. Fig. 5.--Fixation of pollicised index into t h u m b metacarpal. Fig. & - - I m m e d i a t e postoperative result.

FIG. 6

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FIG. 7

SURGERY

FIG. 8

Figs. 7 and 8.--Final range of opposition. Fig. 9.--Case 2. Bilateral club hand in child aged 6. Movement at elbow joints limited and both shoulders dislocating.

FIG. 9

P O L L I C I S A T I O N IN CASES OF RADIAL CLUB HAND

FIG. IO

FIG. II

FIG. 12

FIG. 13

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Figs. Io and I I.--Incisions used to pollicise the little finger. Fig. i 2 . - - W i r e fixation of the metacarpals. Fig. I3.--Extensor tendon freed and displaced medially and slightly anterior to the head of the ulna.

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Fig. i4.--Immediate postoperative result. Fig. Is.--A, The hand holding a pen pre-operatively, with B, the postoperative function for comparison.

FIG. 14

FIG. 15

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FIG. I6 A and B~ Picking up a coin before and after operation.

A

B FIG. I7 As The right hand reaching the mouth before operation, with B, the left hand after operation.

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supplemented by abduction and allowed pronation of the digit to occur. A loop of extensor carpi ulnaris was passed around the displaced extensor to maintain its new position. The abductor minimi digiti was freed to allow it to act more directly on the new position of the digit. A small free graft was required to make good a skin defect on the dorsum of the hand. A plaster of Paris cast was applied to maintain immobilisation for a period of four weeks. The end result is shown in Figures 14 to 17. CONCLUSION

In congenital deformities of the hand in which the thumb is missing, pollicisation of the radial digit is the method of choice. In the congenital deformities alleged to be due to thalidomide, a definite pattern of deformity exists in which dysgenesis is progressively more severe from the ulnar to the radial side. In those cases in which the deformity is relatively slight and the thumb is absent, pollicisation on the radial side, as in other congenital deformities, is preferable, but in those cases with radial club hand complicated by elbow and shoulder deformities, the ulnar digits of the hand are more dynamic than the radial, and it is on this side of the hand that one should seek to restore function. It would be unwise at this stage to do more than present this case as a preliminary report. It is emphasised, however, that an opposition digit is essential to the proper function of the hand, and any procedure which will improve function in these severely handicapped children is justifiable. It is necessary to use to the best advantage the available material based on a correct analysis of function. SUMMARY Two cases are reported of pollicisation for congenital deformities, one on the radial side of the hand and one on the ulnar. The indications for these procedures and the operative procedures are described. M y thanks are due to Mrs Raymond Ramsay of the Lady Hoare Thalidomide Foundation for arranging to let me see a number of these deformed children, and to the surgeons and medical practitioners for allowing me to treat their patients.