The Journal of Foot & Ankle Surgery 53 (2014) 331–334
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Rare Presentation of Foot Postaxial Polydactyly Atif Raﬁque, MBBS, FCPS (Plastic Surgery), EBPRAS 1, Ambreen Arshad, MBBS 2, Ahmed Abu-Zaid 3 1
Assistant Consultant Plastic Surgeon, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia Trainee Member, College of Physicians and Surgeons Pakistan, Karachi, Pakistan; and Attach e, Surgical Intensive Care Unit, King Faisal Specialist Hospital and Research Centre Riyadh, Saudi Arabia 3 Medical Student, ALfaisal University College of Medicine, Riyadh, Saudi Arabia 2
a r t i c l e i n f o
a b s t r a c t
Level of Clinical Evidence: 4
Polydactyly is a prevalent birth anomaly observed in the foot, and a number of classiﬁcation systems have been suggested for this condition. Postaxial (ﬁfth or little toe) polydactyly is the most common type. We encountered an exceedingly rare presentation of foot postaxial polydactyly that, to our inspection, had neither been previously classiﬁed nor described in published studies. In the present report, we have described an otherwise healthy 2-year-old female who had presented to our clinic with an isolated, extra little toe on her left foot. Foot radiographs revealed the presence of all 5 metatarsals; however, the ﬁfth metatarsal was blocked and did not give rise to the ﬁfth toe. Instead, the ﬁfth (medial normal) and sixth (lateral extra) toes had originated from a single, separate accessory bud from the fourth metatarsal, and the main fourth metatarsal had given rise to the normal fourth toe. The lateral sixth toe was excised, and a periosteal sleeve of the excised extra toe was used for reconstruction of the lateral collateral ligament. We propose that this heretofore unmentioned presentation of postaxial polydactyly be added to the existing systems of classiﬁcation of pedal polydactyly. A review of the published data pertaining to pedal polydactyly has also been presented. Ó 2014 by the American College of Foot and Ankle Surgeons. All rights reserved.
Keywords: child congenital anomaly malformation metatarsal phalanx toe
Foot polydactyly is one of the most commonly encountered birth malformations worldwide (1–3). It has been deﬁned as a congenital anomaly characterized by the presence of extra toes, including phalanges, with or without metatarsals (4). Several classiﬁcation systems for polydactyly have been described in published studies (Fig. 1) (2,3,5–7). It can be categorized into preaxial, central, and postaxial forms. Foot postaxial polydactyly, or the presence of an extra digit adjacent to little (ﬁfth) toe, has been the most common form of pedal polydactyly, accounting for 77% to 85% of reported cases (1,7–9). Duplication of the proximal phalanx with an associated wide metatarsal head has been the most frequent anatomic variant (1,8). Polydactyly can occur as an isolated condition or in association with a particular genetic syndrome (5). The clinical presentation will vary and can include pain, difﬁculty ﬁtting shoes, and cosmetic considerations (4). Surgical excision of the extra digit with reconstruction has been the mainstay of management, with good to excellent results reported in published studies (1,8,10,11). In the present report, we have described the case of an otherwise healthy 2-year-old female,
Financial Disclosure: None reported. Conﬂict of Interest: None reported. Address correspondence to: Atif Raﬁque, MBBS, FCPS (Plastic Surgery), EBPRAS, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia. E-mail address: [email protected]
who presented with isolated left foot postaxial polydactyly and atypical radiographic ﬁndings that we do not believe have been previously reported. A review of the published data related to pedal polydactyly has also been presented. Case Report A 2-year-old female presented, with her parents, to our clinic with a parental concern of an isolated extra left little toe with no other medical illness and no other congenital deformity (Fig. 2). The supernumerary ﬁfth toe made it difﬁcult for the child to wear shoes without cutaneous irritation, and the parents were also concerned about the appearance of the extra toe. We obtained radiographs of the child’s left foot and noted the usual 5 metatarsals. However, the distal aspect of the ﬁfth metatarsal was blocked, with elongation of the medial condyle of the head, and the ﬁfth metatarsal did not appear to articulate with a toe. Instead, the ﬁfth and supernumerary sixth toes articulated with a separate osseous bud that had originated and extended laterally from the fourth metatarsal, and the distal, medial portion of the primary fourth metatarsal articulated with the fourth toe (Figs. 3 and 4). After discussions with the parents and preparation of the patient, we took the child to the operating room and, under general anesthesia with laryngeal mask, we applied the tourniquet at the thigh area and inﬂated it after we prepped and draped the patient
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A. Raﬁque et al. / The Journal of Foot & Ankle Surgery 53 (2014) 331–334
Fig. 1. Venn-Watson classiﬁcation. (A) Preaxial polydactyly of the big toe (short block ﬁrst metatarsal), (B) preaxial polydactyly of the big toe (wide metatarsal head), (C) postaxial polydactyly of the little toe (Y-metatarsal), (D) postaxial polydactyly of the little toe (Y-metatarsal), (E) postaxial polydactyly of the little toe (T-metatarsal), (F) postaxial polydactyly of the little toe (wide metatarsal head), and (G) postaxial polydactyly of the little toe (complete duplication).
(100 mm Hg more than the systolic pressure of the patient). We reconstructed the lateral collateral ligament of the metatarsophalangeal joint of the left little toe using an elliptical incision. We reconstructed the lateral collateral ligament of the metatarsophalangeal joint of the left little toe using polypropylene sutures, and the residual periosteal sleeve of the excised supernumerary digit. The superﬁcial fascia and skin layers were then closed using absorbable sutures. She was initially bandaged lightly with cotton roll, and we applied a complete plaster of Paris cast to reduce the mobility of the reconstructed lateral collateral ligament. We allowed weight on her foot, as tolerated, at 1 week. She proceeded to heal unremarkably, and at 4 months postoperatively, she displayed a well-healed postoperative scar and no evidence of any complications related to the surgery (Fig. 5). Discussion Polydactyly is the most common birth deformity of the forefoot, with an overall incidence of approximately 2 cases per 1000 live
births (1–3). The frequency of pedal polydactyly differs signiﬁcantly among populations and has been particularly high in African and Asian populations (12). Foot postaxial polydactyly has been the most predominant form in African populations, and foot preaxial polydactyly has been the most predominant form in Asian (ie, Hong-Kong, Philippine, and Malaysian) populations (12). Foot polydactyly is a congenital malformation characterized by the presence of 6 or more toes, with or without duplication of the corresponding metatarsals or phalanges (4). The supernumerary toe can be well developed and functional or rudimentary and nonfunctional. Bilateral involvement will be present in 50% of patients with foot polydactyly, and symmetry will be present in 62% of the bilateral cases (8). Hand polydactyly and syndactyly has been associated with 34% and 22% of patients with foot polydactyly, respectively (8). A number of classiﬁcation systems of foot polydactyly have been suggested in published studies (2,3,5–7). According to the anatomic location of the extra toe, Temtamy and McKusick (5) classiﬁed foot polydactyly into preaxial, central, and postaxial forms. Preaxial
A. Raﬁque et al. / The Journal of Foot & Ankle Surgery 53 (2014) 331–334
Fig. 2. Preoperative clinical appearance of left foot postaxial polydactyly.
Fig. 3. Preoperative anteroposterior radiographic appearance of the left foot.
polydactyly signiﬁes the presence of an extra digit on the medial (big toe, hallux) side of the foot, and postaxial polydactyly signiﬁes the presence of an extra digit on the lateral (little, ﬁfth) toe side of the foot. Central polydactyly signiﬁes the presence of an extra digit in the middle of the foot (between the ﬁrst and ﬁfth toes). Postaxial polydactyly is the most common form of pedal polydactyly, accounting for 77% to 87% of cases (1,7–9). Preaxial polydactyly is the second most prevalent form, accounting for 8% to 15% of the cases (7,8), with central polydactyly accounting for approximately 6% of the cases (7,8). Duplication of the proximal phalanx, with widening of the corresponding metatarsal head, has been the most frequent anatomic variant of foot postaxial polydactyly (1,8). Regarding the maturation of the tissues of the supernumerary toe, Temtamy and McKusick (5) further classiﬁed postaxial polydactyly into type A, in which a completely developed toe is present, and type B, in which the supernumerary digit is a boneless soft tissue rudiment. Regarding the morphologic arrangement of the ray (metatarsal and toe), Venn-Watson (2) classiﬁed foot postaxial polydactyly into 5 distinct anatomic variants (Fig. 1). From the most differentiated to the least differentiated variant, the Venn-Watson patterns include complete ray duplication, Y-shaped metatarsal, T-shaped metatarsal, a normal metatarsal shaft with wide head, and soft tissue duplication. Preaxial polydactyly was further classiﬁed into short block ﬁrst metatarsal and normal metatarsal to metatarsal, with a widened head and phalangeal duplication. Lee et al (3) studied 113 cases of foot postaxial polydactyly and accordingly proposed a classiﬁcation system based on the origin of the extra digit: middle phalangeal, proximal phalangeal, ﬂoating, ﬁfth metatarsal, and fourth metatarsal. The proximal phalangeal type was further divided into 3 variants: lateral proximal phalangeal, medial proximal phalangeal, and phalangeal head variants. In the middle phalangeal, proximal phalangeal head, medial proximal phalangeal, and fourth metatarsal types, the extra ﬁfth ray digit will be located medially. In contrast, in the lateral proximal phalangeal
lateral, ﬂoating, and ﬁfth metatarsal types, the extra ﬁfth ray digit will be located laterally. Duplication of the medial proximal phalanx was the most common anatomic variant of foot postaxial polydactyly. In our case report, although the ﬁfth metatarsal was present, it was blocked and did not give rise to the ﬁfth toe (Fig. 2). Instead, the ﬁfth (normal medial) and sixth (supernumerary lateral) toes articulated with a secondary, accessory osseous bud that had originated from the fourth metatarsal, and the primary (main) fourth metatarsal gave rise to the normal fourth toe. To the best of our knowledge, this particular anatomic conﬁguration of postaxial pedal polydactyly has not been
Fig. 4. Schematic illustration of atypical postaxial pedal polydactyly.
A. Raﬁque et al. / The Journal of Foot & Ankle Surgery 53 (2014) 331–334
Fig. 5. Anteroposterior radiograph of the left foot 4 months postoperatively.
documented in published studies until now. This particular pattern of postaxial pedal polydactyly does not appear to ﬁt into any existing classiﬁcation system; thus, we propose it be added as an additional form. The precise etiology of foot polydactyly remains unknown. However, the most broadly accepted theory has been that it is an inherited trait, and a positive family history has been established in 30% (8) to 39% (5) of cases. The condition is the most common presentation and seems to be inherited in an autosomal dominant manner, with variable expression and incomplete penetrance (13). As such, genetic counseling should be considered for those who have had difﬁculty with pedal polydactyly, primarily for informational purposes. However, other modes of inheritance and a sporadic incidence have also been described (14). Plenty of genetic syndromes have been associated with a polydactyly component, including Ellis van Creveld syndrome, Smith-Lemli-Opitz syndrome, Bardet-Biedl syndrome, short rib-polydactyly syndrome, MeckelGruber syndrome, trisomy 13, trisomy 21, tibial hemimelia, and others (1,15–19). Because foot polydactyly appears to be caused by several genes, genetic testing will not be clinically feasible. Also, even if it was feasible, it could only support the clinical diagnosis and would not alter the clinical treatment of the patient or subsequent offspring (20). The clinical presentation of polydactyly is diverse and includes spontaneous pain, excruciating walking tenderness, ill-ﬁtting shoe concerns, cosmetic problems, and psychosocial difﬁculties (4). The point of presentation for clinical care has varied and ranges from early infancy to late toddlerhood/childhood. Foot polydactyly should primarily be managed surgically, although shoe customization is an option for nonsurgical candidates. Surgical intervention is highly advised during childhood and before the child has started walking (5). The rationale behind early surgical intervention has been to maximize the time for the reconstructed bones to remodel and adapt to the new structural arrangement. Foot polydactyly presentation in adulthood is rare, and its surgical management remains controversial (5). Regarding treatment, meticulous clinical and radiologic evaluation before surgical repair has been recommended (21). In addition, the management should be individualized (personalized), with the ultimate goal being restoration of a normal or near-normal foot structure and function. Excising the supernumerary digit, with subsequent careful reconstruction, should be the mainstay of
treatment, and excellent long-term outcomes have been reported for the surgical treatment of postaxial polydactyly (1,8,10,11). However, poor long-term outcomes have been reported for the surgical treatment of preaxial polydactyly (20). The long-term complications associated with the surgical treatment of postaxial pedal polydactyly have included clinically insigniﬁcant angular deformities. Recurrent hallux varus and a short ﬁrst metatarsal that does not satisfactorily support weightbearing have been reported in association with the surgical treatment of preaxial polydactyly. Also, the management of central polydactyly has not been well documented in published studies, largely owing to its limited occurrence. The management of this form of polydactyly has varied from uncomplicated shoe customization to complicated surgical procedures. The key principles in the management of polydactyly of the foot include preserving the most developed toe that has the most normal metatarsophalangeal conﬁguration and that will provide the best shape for the foot (5). The long-term complications related to central pedal polydactyly have included a sustained wide-based forefoot (20). In conclusion, postaxial pedal polydactyly is the most common form of supernumerary toe formation, and we have described an unusual variant that responded well to surgical excision of the extra toe in a 2-year-old female. Foot surgeons should be aware of this variation of the malformation and should also understand the different patterns of foot polydactyly and be aware that other conditions can be associated with the disorder.
References 1. Turra S, Gigante C, Bisinella G. Polydactyly of the foot. J Pediatr Orthop B 16:216– 220, 2007. 2. Venn-Watson EA. Problems in polydactyly of the foot. Orthop Clin North Am 7:909–927, 1976. 3. Lee HS, Park SS, Yoon JO, Kim JS, Youm YS. Classiﬁcation of postaxial polydactyly of the foot. Foot Ankle Int 27:356–362, 2006. 4. Galois L, Mainard D, Delagoutte JP. Polydactyly of the foot: literature review and case presentations. Acta Orthop Belg 68:376–380, 2002. 5. Temtamy S, McKusick VA. The genetics of hand malformations with particular emphasis on genetic factors. Birth Defects 14:364–423, 1969. 6. Blauth W, Olason AT. Classiﬁcation of polydactyly of the hands and feet. Arch Orthop Trauma Surg 107:334–344, 1988. 7. Watanabe H, Fujita S, Oka I. Polydactyly of the foot: an analysis of 265 cases and a morphologic classiﬁcation. Plast Reconstr Surg 89:856–877, 1992. 8. Phelps DA, Grogan DP. Polydactyly of the foot. J Pediatr Orthop 5:446–451, 1985. 9. Nakamura K, Youshii M, Nanjyo B. Statistical analysis of congenital upper and lower limb malformations. Japan J Plast Reconstr Surg 31:417–424, 1988. 10. Chiang H, Huang SC. Polydactyly of the foot: manifestations and treatment. J Formos Med Assoc 96:194–198, 1997. 11. Morley SE, Smith PJ. Polydactyly of the feet in children: suggestions for surgical management. Br J Plast Surg 54:34–38, 2001. 12. Murphy KA. A prehistoric example of polydactyly from the iron age site of Simbusenga, Zambia. Am J Phys Anthropol 108:311–319, 1999. 13. Castilla EE, Lugarinho R, da Grac¸a Dutra M, Salgado LJ. Associated anomalies in individuals with polydactyly. Am J Med Genet 80:459–465, 1998. 14. Morrison BE, D’Mello SR. Polydactyly in mice lacking HDAC9/HDRP. Exp Biol Med (Maywood) 233:980–988, 2008. 15. Castilla EE, Lugarihno da Fonseca R, da Graca Dutra M, Paz JE. Hand and foot postaxial polydactyly: two different traits. Am J Med Genet 73:48–54, 1997. 16. In: Smith’s Recognizable Patterns of Human Malformation, 5th ed., p. 816, edited by KL Jones, DW Smith, WB Saunders, Philadelphia, 1997. 17. Krakow D. The dysostoses. In: Emery and Rimoin’s Principles and Practice of Medical Genetics, 4th ed., pp. 4160–4181, edited by DL Rimoin, JM Connor, RE Pyeritz, BR Korf, Churchill Livingstone, New York, 2002. 18. Auyeung J, Bhattacharya R, Birla R, Hide G, Henman P. The occult toe: an unusual case of polydactyly in the foot. J Pediatr Orthop B 18:362–364, 2009. 19. Klaassen Z, Shoja MM, Tubbs RS, Loukas M. Supernumerary and absent limbs and digits of the lower limb: a review of the literature. Clin Anat 24:570–575, 2011. 20. Masada K, Tsuyuguchi Y, Kawabata H, Ono K. Treatment of preaxial polydactyly of the foot. Plast Reconstr Surg 79:251–258, 1987. 21. Giorgini RJ, Aquinno JM. Surgical approach to polydactyly. J Foot Surg 23:221–225, 1984.