Unfavourable results in pollicisation.

Pollicisation of the index finger is perhaps one of the most complex and most rewarding operations in hand and plastic surgery. It however has a steep learning curve and demands very high skill levels and experience. There are multiple pitfalls and each can result in an unfavourable result. In essence we need to: Shorten the Index, recreate the carpo metacarpal joint from the metacarpo phalangeal (MP) joint, rotate the digit by about 120° for pulp to pulp pinch, palmarly abduct by 40-50° to get a new first web gap, Shorten and readjust the tension of the extensors, re attach the intrinsics to form a thenar eminence capable of positioning the new thumb in various functional positions and finally close the flaps forming a new skin envelope. The author has performed over 75 pollicisations personally and has personal experience of some of the issues raised there. The steps mentioned therefore are an algorithm for helping the uninitiated into these choppy waters.

INTRODUCTION

In the words of Sir Charles Bell:[1] “On the length, strength, free lateral motion and perfect mobility of the thumb, depends the power of the human hand. The thumb is called Pollex because of its strength: And that strength is necessary to the power of the hand, being equal to that of all the fingers.” This is never truer than in cases of congenital absence or hypoplasia of the thumb.

In Indian mythology the sage Dronacharya who taught archery to the princes of Mahabharat, caught a lad ‘Ekalavya’ learning secretly ‘from a distance’. To safeguard his pupils’ supremacy and exclusivity of skills, he demanded his dominant thumb as his ‘Gurudakshina’ (tuition fees) and thus rendering his hand ineffective as an archer. Today Ekalavya would have come right back following a pollicisation.

Pollicisation of the index finger to reconstruct a missing thumb or pollex is therefore one of the finest operations in reconstructive hand surgery. It is simultaneously rewarding to and taxiing, on the surgeon performing it. It is perhaps in my opinion one of the most difficult surgeries in the entire gamut of hand and plastic surgery.

HISTORY

Pollicisation really came into its own after Buck Gramcko's definitive and landmark article[2] on the subject in 1971 in the English language. Before that he had published in German, but was not really accessible to a wider audience. However Buck Gramcko by his own admission was guided by previous papers on the subject by Gosset, Littler, Harrison and so on.[3-7] Light[8] has commented in 2000 that on the occasion of the 50th anniversary of the American Hand Society, a poll was conducted about the most significant papers of the last 50 years. Buck-Gramcko's paper was part of every person's collection. Buck Gramcko attributed his expertise to the thalidomide tragedy in Europe, which led to multiple congenital anomalies and forced him to undertake hitherto unprecedented number of pollicisation procedures, which lead to this final product. A tragedy thus resulted in giving the world a great technique.

Technique

As discussed above, Buck Gramcko's technique[2] remains the gold standard but various authors such as Manske, Kozin and Foucher et al. have modified it and added their own points to it.[9-13] However, essentially the technique at the core remains unchanged. If you think of it conceptually the following points emerge: Table 1 summarises the characteristics of the thumb and index fingers.

Table 1

Characterestics of thumb and index finger

From Table 1, it is obvious that the index is longer than the thumb, but does not have the versatility of its musculature, particularly the intrinsics. In addition, the carpo metacarpal (CMC) joint of thumb is unique in its architecture and allows stable 360° movement to give the unique opposition movement to the human thumb.

The challenge therefore is to shorten the index finger and re-create the CMC joint like a thumb surrounded by the appropriate intrinsics and extrinsic musculature to hold it in the correct position and give it thumb like function.

Table 2 summarises the technical points of ‘who becomes what?’ when the Index is pollicised.

Table 2

Technical points of which structure in index becomes what in the neo thumb

In essence we need to:

Shorten the index

Recreate the Carpo-metacarpal (CMC) joint from the Metacarpo-phalangeal (MP) joint

Rotate the digit by about 120° for pulp to pulp pinch

Palmarly abduct by 40-50° to get a new first web gap

Shorten and readjust the tension of the extensors

Re attach the intrinsics to form a thenar eminence capable of positioning the new thumb in various functional positions.

The author uses the Buck Gramcko technique of pollicisation, and Figures 1 and 2 shows it in detail. We start with the dorsal flaps; the most important point here is the preservation of dorsal veins [Figure 3]. The flaps are therefore extremely thin. We have rarely had problems of viability despite thinning the flaps to almost dermal level. As far as possible all dorsal venous network is preserved

Figure 1

Buck Gramcko type markings for palmar side

Figure 2

Buck Gramcko type markings for dorsal side

Figure 3

Dorsal flaps raised preserving veins

Next is the isolation of the pedicles [Figures 4 and 4a] and if required disecting open a neural ring [Figure 5] if it is present in the ulnar sided pedicle

Figure 4

(a) Ulnar side nerve with faint vascular pedicle. (b) Ulnar side vascular pedicle, branch to middle finger will be ligated

Figure 5

Neural ring on the ulnar side nerve, branch of the artery to middle finger ligated

Once the pedicles are secured we expose, isolate and divide the first dorsal interosseous (FDI) and first palmar interosseous (FPI) with an extension of the lateral bands. The residual lateral band is tagged with a 6/0 nylon suture to identify it at the time of final suturing [Figures 6 and 7]

Figure 6

First dorsal interroseous raised with tendon, lateral band on finger tagged with 6/0 nylon loose stitch for later identification

Figure 7

First palmar interroseous raised with tendon, lateral band on finger tagged with 6/0 nylon loose stitch for later identification

The two long extensors are identified under the veins and fat dorsally. I like to call this the lipo venous plane [Figure 8] and it is in continuity with the dorsal veins identified earlier [Figure 3]. The Extensor Indicis Proprious (EIP) and ED are exposed [Figure 9], cut and proximal ends held with haemostats. Distally the EIP side of the extensor hood is taken off the dorsal part of the metacarpophalangeal (MCP) joint capsule to enable it to exert a direct pull on the distal interphalangeal joint. The ED attachment is left in place to become the future Abductor pollicis longus (APL) insertion [Figure 10]

Figure 8

Retractor holding the ‘lipovenous plane’, below it is the extensor tendons

Figure 9

Extensor digitorum communis and Extensor Indicis proprious seen

Figure 10

Extensor digitorum communis Extensor Indicis proprious cut proximal ends in haemostats, distally EIP raised off MP joint so as to act on distal interphalangeal as future extensor pollicis longus

The dorsal flap on hand is elevated fully once again preserving the veins [Figure 11]

Figure 11

Dorsal flap raised and venous network preserved in continuity with those of Fig. 3

The deep transverse metacarpal ligament between the index and middle fingers is divided finally. The index is now free of all attachments

The metacarpal is divided at the level of the head thru the epiphysis. The shaft is excised down to and including its base from the CMC joint extraperiosteally [Figures 12, 12a and 13]. Great care is taken to avoid damage to neurovascular pedicle of the intrinsics of the index

Figure 12

(a) Extra-periosteal dissection of index finger metacarpal. (b) Cut at the level of the head of the metacarpal

Figure 13

Metacarpal excised carpo metacarpal joint seen

The metacarpal head is rotated dorsally by 90° and fixed with a 4/0 nylon suture figure to prevent hyperextension of the new CMC joint [Figure 14] as described by Buck Gramcko[2] This free index is now rotated 150°, abducted 40-50° and fixed at the CMC level to the hollow in the CMC of the index with another 4/0 nylon stitch [Figure 15]. The initial rotation of 150° reduces to about 120° during suturing.[2]

Figure 14

Turning the metacarpal head in extension and suturing it

Figure 15

Fixing the islanded Index finger into new carpo metacarpal joint after excising its metacarpal thru the neck

Extensors are sutured first in full extension [Figure 16], once the flexors shorten over the next few months this gets compensated nicely. A1 pulley resection helps this happen [Figure 17]

Figure 16

Adjusting tension on extensor tendon. Note the pouce flottant still present in dorsal skin flap on the left of the picture

Figure 17

Releasing A1 pulley of the flexors

The FDI and FPI are sutured to their respective lateral bands elevated up to proximal interphalangeal joint (new MP joint) in appropriate tension [Figures 18 and 19]. More tension on the FDI to get abduction properly

Figure 18

Suturing first dorsal interosseous to lateral band as the new abductor pollicis brevis

Figure 19

Suturing first palmar interosseous to lateral band as the new adductor pollicis

The skin flaps are sutured to position the new pollex appropriately. It is often not appreciated, but this is perhaps the most important way of maintaining the position of the new pollex [Figures 20 and 21].

Figure 20

Side view of skin closure

Figure 21

Palmar view of skin closure

The dressing is with fluffed gauze [Figures 22 and 22a] gamgee and a crepe elastic bandage and is bulky [Figure 23].

Figure 22

(a) Fluffed gauze. (b) Tulle and povidone iodine soaked gauze as first layers. Note they are non-circumferential

Figure 23

Bulky final dressing

UNFAVOURABLE RESULTS

Each of the steps described above can go wrong or be subotimal leading to unfavourable results.

The possible unfavourable results are listed below:

The worst outcome is losing the finger. It has not happened in my experience, but damage or kinking of pedicles can possibly lead to it. We have abandoned a case with vascular issues and managed to salvage the finger with marginal necrosis, which healed with conservative treatment. Figure 24 shows venous congestion, which eventually resolved

Figure 24

Jeopardy with venous congestion

Skin necrosis: Some parts of the flaps can necrose due to poor vascularity as shown in Figure 25, however most of them respond to conservative treatment. We have never had to formally excise and graft such a defect

Figure 25

Flap necrosis

Too long pollex [Figure 26], usually caused by either not cutting the metacarpal head at the proper place or by growth from retained epiphysis [Figure 27]. May need shortening. However patients’ feedback is critical before doing this. Many patients are happy with the result and do not wish to be adjusted or disturbed further

Figure 26

Too long pollex

Figure 27

Bone spike growing due to retained periosteum

Hyperextension at CMC joint. If step 8 above is followed properly this is never an issue

Inappropriate positioning due to skin excess [Figure 28]. Appropriate skin trimming is a good option for very effective treatment [Figure 29]

Figure 28

Preoperative poor function due to excess skin

Figure 29

Good opposition following skin adjustment

Bone spike: Usually at the base of new pollex caused by either keeping periosteum during excision of the metacarpal shaft or keeping a remnant of metacarpal base. Both are avoided by doing an extraperiosteal disarticulation of the 2nd metacarpal from its CMC joint.

DISCUSSION

In an article written by Goldfarb et al.[14] a cohort of 73 cases are studied for complications and unfavourable results. Their results and conclusions are quoted. ‘There were eight complications in the perioperative period (including three cases of venous congestion, four cases of marginal necrosis and one infection), requiring 12 surgical procedures; one pollicised digit was removed owing to non-viability. There were eight suboptimal outcomes, including seven cases of scar contracture and one with redundant skin, requiring three surgical procedures. Additional procedures related to functional deficiencies were performed in 26 total patients, 19 for poor opposition and 15 for limited extension.

They conclude that most perioperative complications and suboptimal outcomes after pollicisation are minor when an experienced surgeon is involved. Venous congestion, although uncommon, is a major viability risk and should be treated aggressively. In addition, a substantial number of pollicised digits have functional deficiencies related to anatomical limitations that can be addressed with muscle and tendon transfers.’

In 1991, Prof Buck Gramcko wrote an article[15] on complications and unfavourable results in his experience. I am fortunate to get this rare article translated from German to add to this discussion. Prof. Buck Gramcko listed the following points in complications and suboptimal results:

Improper indication: Five fingered hand with poor quality radial digit, borderline Grade III hypoplasia etc

Improper skin incisions: Can result in narrow first web, compression of pedicle due to tight suturing

Damage to Neuro vascular structures: As mentioned above can very rarely lead to loss of the digit. He has reported 12 cases of vascular injury (Arterial) in 460 cases and one complete loss of digit. In that case, the finger was anomalously supplied by metacarpar arteries, which thrombosed following the translocation. Rarely damage to motor nerves of FDI can result in loss of abduction and needs a subsequent opponensplasty using flexor digitorum superficialis of the middle finger

Skeletal issues: Too long thumb (discussed above), hyperextension at new CMC joint – must be avoided by rotating the head of the 2nd metacarpal and suturing it in extended position as mentioned in step 8 of operative technique

Skin problems; marginal necrosis, improper formation of the first web, etc., needs to be tackled on merits.

Late Prof Paul Manske, wrote a review article in 2010[16] and discussed both the technique as well as poor results. His conclusions are similar to the article by Goldfarb et al.[14] His series in that the paper had three cases of venous congestion and one finger was lost.

Sykes et al. published a method of assessing pollicisation and a review of their 30 cases.[1718] They studied, tip pinch, pulp pinch, opposition, grasp, mobility, sensibility and cosmetic. Based on their own scoring system, which is widely accepted now their results in 30 cases were 73%, were graded good or excellent, 17% fair and 10% as poor. 36% required secondary surgery to achieve a satisfactory result. Better results were obtained in Blauth III or IV deformities, with poorer outcomes in Blauth V or patients with associated radial hypoplasia.

We have analysed our own data in 17 children and 21 hands, all with radial dysplasia functionally the percival score was excellent and good in 12 patients, fair in 3 and poor in 2. The patients who had fair or poor results had a more severe grade of radial dysplasia or a more severe Blauth grade.

Pollicisation was not always popular or considered a ‘good’ operation to reconstruct a missing thumb. White[7] in 1969 said: ‘A transposed index finger can never be made into a thumb especially in the congenital cases and it may not be wise to strive too hard by means of transplants to emulate the perfection of a normal thumb, you cannot make a silk purse out of a sow's ear but, if sensation, good position and proximal stability are achieved then there can be a useful addition to hand function which is not too distasteful cosmetically’. This was of course before Buck Gramcko published his landmark paper in 1971[2] which completely changed the perspective as later papers show.

CONCLUSION

Pollicisation is one of the finest operations for reconstruction of thumb aplasia or hypoplasia. Its’ complexity can lead to some unfavourable results. None (except the very rare total loss) are however such that they cannot be improved.