Polydactyly is a fairly common congenital conditionof the foot and is characterized literally by supernu-merary toes (digit or metatarsal). The frequency ofpolydactyly varies widely among populations. It maybe an isolated condition or part of a congenital syn-drome. Polydactyly is generally classified into threemajor groups : medial ray (preaxial), central ray andlateral ray (postaxial). The duplication may appearat the distal and middle phalanges or at the wholedigit and metatarsal. The complexity of the deformi-ty ranges from a simple soft-tissue problem to a com-pletely developed accessory ray. Careful clinical andradiographic evaluation should be made prior totreatment to achieve good functional and cosmeticresults. Most cases are treated during childhoodbefore walking age. Adult cases are more rare, andsurgical management of the deformity is still debat-ed. Nevertheless, surgery can be performed at anyage as in our series with good results.

Keywords : foot ; polydactyly.Mots-clés : pied ; polydactylie.

INTRODUCTION

Polydactyly is a fairly common congenitalcondition of the foot and is characterized by thepresence of supernumerary toes (digit or meta-tarsal). Although reports of polydactyly of the handare numerous, there are few of the foot. The dupli-cation may appear at the distal and middle pha-langes or at the whole digit and metatarsal. Surgicalintervention may be indicated for shoe problems,pain or for cosmetic reasons. The disorder of poly-dactyly has been described and classified in nume-

rous fashions. Most cases are treated during child-hood before walking age. Adult cases are morerare, and surgical management of the deformity isstill debated. A review of the literature and threecases of polydactyly in the adult foot are presented.

CASES PRESENTATIONS

Case 1

A 30-year-old man presented with bilateral par-tial duplication of the fifth toes (fig. 1). There was

Acta Orthopædica Belgica, Vol. 68 - 4 - 2002

POLYDACTYLY OF THE FOOT. LITERATURE REVIEW AND CASE PRESENTATIONS

L. GALOIS, D. MAINARD, J. P. DELAGOUTTE

————————Service de Chirurgie Orthopédique et Traumatologique

(C.O.T), Hôpital Central, Nancy, France.Correspondence and reprints : L. Galois, Service de

Chirurgie Orthopédique et Traumatologique (C.O.T), HôpitalCentral, 29 avenue Maréchal de Lattre de Tassigny, C.O n° 34,54035 Nancy Cedex, France. E-mail : lgalois@free.fr.

Fig. 1. — Partial duplication of the fifth toe

POLYDACTYLY OF THE FOOT 377

no problem with shoes, but the main problem wascosmetic and also psychological. Xray showedduplication of the middle phalanx (fig. 2). Excisionof the medial supernumerary toe was easily per-formed on both feet. The outcome was favorablewith no complaints (fig. 3).

Case 2

A 30-year-old female presented with a chiefcomplaint of a painful left foot. The left footdemonstrated a widened midfoot especiallybetween the fourth and fifth metatarsals (fig. 4). Onanteroposterior xray examination, there was partialduplication of the fifth metatarsal enlarging thefourth intermetatarsal space (fig. 5). Shoe problemswere the main complaint. Therapy consisted of sur-

gical excision of the duplicated metatarsal andrepair of the transverse intermetatarsal ligament toprevent splaying of the foot. The cosmetic resultwas good (fig. 6), and the patient was able to wearmost shoes without the necessity of modification,custom-made shoes or pairing of different sizes.

Case 3

A 26-year-old female presented with a moder-ately widened midfoot and six toes (fig. 7). Shewanted to get married, and esthetic shoe-wear wasproblematic. On anteroposterior xray examinationthere were six complete metatarsals and toes. Thefifth ray seemed to be more rudimentary, and exci-sion of the fifth ray was chosen. It was performedthrough a dorsal incision (fig. 8). The transverse

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Fig. 2. — Xray showing a duplication of the middle phalanx Fig. 3. — Final appearance. Good cosmetic result

378 L. GALOIS, D. MAINARD, J. P. DELAGOUTTE

intermetatarsal ligament was carefully repaired.The long-term result was good with no problemwith shoes.

DISCUSSION

Polydactyly is a fairly common congenital con-dition of the foot. Several classifications have beenproposed in the literature (1, 3, 4, 7) to systematizethis variable malformation. The classification sys-tems used for polydactyly have been primarilybased on morphology. Polydactylous manifesta-tions are described according to their anatomicallocation on the proximal, intermediate, or distalsegments of the foot. Temtamy and McKusick’s

classification defines the disorder as being eitherisolated or part of a syndrome (7). They describedpolydactyly based on the location of the extra dig-its : medial ray (preaxial), central ray and lateralray (postaxial) with the postaxial type A referringto a fully developed digit and type B to a rudimen-tary digit. Venn-Watson (8) further subdividedpostaxial duplication according to the morphologicpresentation of the accessory ray. Four metatarsalpatterns were noted : soft-tissue duplication, widemetatarsal head, Y-shaped metatarsal and completeduplication. In 1988, Blauth and Olason (1) tookinto consideration the many variable presentationsof polydactyly of the foot and hand. The classifica-tion was based on the position of duplication on

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Fig. 4. — A 30-year-old female with a widened midfoot espe-cially on the lateral side between the fourth and fifthmetatarsal.

Fig. 6. — Final aspect after surgical correction with a goodcosmetic result.

Fig. 5. — Xray showing a partial duplication of the fifthmetatarsal enlarging the fourth intermetatarsal space.

Fig. 7. — A 26-year-old female with a six- toed foot

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both the longitudinal and transverse plane. The lon-gitudinal nomenclature is based on duplication of aphalanx or ray from distal to proximal. The trans-verse arrangement of the classification indicateswhich rays were involved in the duplication. It isclassified according to Roman numerals with thefirst digit starting on the tibial side and increasinglaterally. Lastly, Watanabe et al. (9) reported ananalysis of 265 cases and a morphological classifi-cation by type of ray involvement and level ofduplication. The anatomic pattern types in medial-ray polydactyly are tarsal, metatarsal, proximal anddistal phalangeal. Central-ray pattern types aremetatarsal, proximal, middle and distal phalangeal.Lateral-ray polydactyly was further divided intofifth-ray duplication (medial supernumerary toe)and sixth-ray duplication (lateral supernumerarytoe). Digital duplications range from boneless soft-tissue structures to incomplete or complete bonyduplications. The frequency of polydactyly varieswidely among populations (6). The high frequencyof polydactyly in populations of Africa and Asiamust be pointed out. The exact human embryolog-ical parameters behind polydactyly are unknown.Of the three types (preaxial, postaxial, central)postaxial polydactyly occurs most frequently (9).The majority of polydactyly reported in the Africanpopulation is postaxial in nature. In contrast, in thePhilippines, in Hong-Kong and in Malaysia, themajority of polydactyly is preaxial in nature (6).

We found the classification proposed byWatanabe et al. (9) to be simple but complete. Thisclassification clearly indicates the type of anomalywhich is very important in planning the surgery. Inmost cases of postaxial polydactyly, the surgicalprocedure is relatively simple (excision of the late-ral digit) and long-term results have been good toexcellent in most studies (2). In our series ofpostaxial polydactyly, the results were comparableto those obtained in the literature. Surgical correc-tion of preaxial polydactyly is generally more com-plex with poor long-term results (5). Complicationsinclude recurrent hallux varus, splaying of the firstray and a short first metatarsal that does not bearadequate weight. Treatment of central ray duplica-tion is not well publicized because of its rare pre-sentation. In most cases, supernumerary centraldigits can be excised through a racquet-shapedincision. Treatment ranges from shoe modificationto complex surgical procedures. General principlesrecommend saving the digit that is the most devel-oped, that has the most normal metatarsopha-langeal articulation and that will give the best con-tour to the foot. Surgery should not be delayedmuch beyond walking age to allow the maximumtime for the bones to remodel. Nevertheless,surgery can be performed at any age as in our serieswith good results. Management of polydactyly ofthe foot may appear simple at first glance, but themultiformity of its configuration deserves carefulconsideration before and during surgical correc-tion. Whatever the motive for the patient to consult,shoe problems, pain or cosmetic reasons, the treat-ment should be individualized. If surgical correc-tion is elected, it should lead to proper alignment oftoes and comfort in wearing shoes.

REFERENCES

1. Blauth W., Olason A. T. Classification of polydactyly of thehands and feet. Arch. Orthop. Trauma. Surg., 1988, 107,334-344.

2. Chiang H., Huang S. C. Polydactyly of the foot : Mani-festations and treatment. J. Formos. Med. Assoc., 1997, 96,194-198.

3. Coppolelli B. G., Ready J. E., Awbrey B. J., Smith L. S.Polydactyly of the foot in adults : Literature review andunusual case presentation with diagnostic and treatmentrecommendations. J. Foot Surg., 1991, 30, 12-18.

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Fig. 8. — Postoperative view after radial excision of the fifthray.

380 L. GALOIS, D. MAINARD, J. P. DELAGOUTTE

4. Kleanthous J. K., Kleanthous E. M., Hahn P. J. Jr.Polydactyly of the foot. Overview with case presentations.J. Am. Podiatr. Med. Assoc., 1998, 88, 493-499.

5. Masada K., Tsuyuguchi Y., Kawabata H., Ono K. Treatmentof preaxial polydactyly of the foot. Plast. Reconstr. Surg.,1987, 79, 251-258.

6. Murphy K. A. A prehistoric exemple of polydactyly fromthe iron age site of Simbusenga, Zambia. Am. J. Phys.Anthropol., 1999, 108, 311-319.

7. Temtamy S., McKusick V. A. The genetics of hand malfor-mations with particular emphasis on genetic factors. BirthDefects, 1969, 14, 364-423.

8. Venn-Watson E. A. Problems in polydactyly of the foot.Orthop. Clin. North Am., 1976, 7, 909-927.

9. Watanabe H., Fujita S., Oka I. Polydactyly of the foot : Ananalysis of 265 cases and a morphological classification.Plast. Reconstr. Surg., 1992, 89, 856-877.

SAMENVATTING

L. GALOIS, D. MAINARD, J. P. DELAGOUTTE. Poly-dactalie van de voet. Literatuurstudie en voorstellingvan gevallen.

Polydactalie van de voet, gekenmerkt door de aan-wezigheid van supernumeraire tenen en eventueelmetatarsalen, is niet zeldzaam. De frequentie vanvoorkomen verschilt volgens bevolkingsgroep. Poly-dactilie komt geïsoleerd voor, maar ook in een congeni-taal syndroom samen met andere afwijkingen.Drie groepen worden onderscheiden : polydactylie vande mediale straal (preaxiaal), de centrale straal en delaterale straal (postaxiaal). De ontdubbeling kan zichbeperken tot een eenvoudig weekdeel probleem, een

splitsing van het middenste en distale kootje van de teen,een splitsing van de ganse teen, en een splitsing van demetatarsaal, zodat een volledig ontwikkelde bijgevoegdestraal is gevormd. Een goed cosmetisch en functioneelresultaat vereist een zorgvuldige klinische en radio-logische oppuntstelling. De behandeling gebeurt meestalvóór de loopleeftijd is bereikt. Bij volwassenen is heel-kunde aanvechtbaar, alhoewel de auteurs goede resul-taten bereikten op gelijk welke leeftijd.

RÉSUMÉ

L. GALOIS, D. MAINARD, J. P. DELAGOUTTE. Lespolydactylies au pied. Analyse de la littérature et cascliniques.

Les polydactylies au pied, malformation congénitalerare, se caractérisent par l’existence d’un orteil sur-numéraire (phalange ou métatarsien). Leur fréquence estvariable selon les populations étudiées. La malformationpeut être isolée ou associée à un syndrome polymalfor-matif. Les polydactylies sont généralement classées en3 groupes : formes médiales, centrales et latérales. Laduplication peut ne concerner que l’appareil phalangienou l’ensemble du rayon. L’existence de très nombreusesformes cliniques (de la plus simple à la plus complexe)exige une évaluation clinique et radiographique pré-opératoire rigoureuse dont dépendra le résultat. Dans lamajorité des cas, le traitement chirurgical est effectuépendant la petite enfance avant l’âge de la marche. Lesformes cliniques à l’âge adulte sont plus rares et leurtraitement fait toujours l’objet de discussions. Néan-moins, la correction chirurgicale peut être pratiquée àtout âge comme dans notre série.

Acta Orthopædica Belgica, Vol. 68 - 4 - 2002