M C e o d n i t ca in l u ORTHOTICS & BIOMECHANICS Ed in u g c at io n Goals and Objectives At the completion of this article, the physician will be able to: Ectrodactyly 1) Define ectrodactyly of the foot. 2) List the various ectrodactyly as - sociated syndromes and characteris - of the Foot tics of each. 3) Discuss the common presenting clinical findings of ectrodactyly. Here’s an overview for the 4) Understand the basic human embryology and genetics associated evaluation and treatment of with the ectrodactyly defect. this condition. 5) Classify a pedal ectrodactyly de - formity based on roentgenographic findings 6) Develop a treatment plan for a patient with pedal ectrodactyly. Welcome to Podiatry Management ’s CME Instructional program. Our journal has been approved as a sponsor of Contin - uing Medical Education by the Council on Podiatric Medical Education. You may enroll: 1) on a per issue basis (at $20.00 per topic) or 2) per year, for the special introductory rate of $139 (you save $61). You may submit the answer sheet, along with the other information requested, via mail, fax, or phone. In the near future, you may be able to submit via the Internet. If you correctly answer seventy (70%) of the questions correctly, you will receive a certificate attesting to your earned cred - its. You will also receive a record of any incorrectly answered questions. If you score less than 70%, you can retake the test at no additional cost. A list of states currently honoring CPME approved credits is listed on pg. 170 . Other than those entities currently accepting CPME-approved credit, Podiatry Management cannot guarantee that these CME credits will be accept - able by any state licensing agency, hospital, managed care organization or other entity. PM will, however, use its best efforts to ensure the widest acceptance of this program possible. This instructional CME program is designed to supplement, NOT replace, existing CME seminars. The goal of this program is to advance the knowledge of practicing podiatrists. We will endeavor to publish high quality manuscripts by noted authors and researchers. If you have any questions or comments about this program, you can write or call us at: Podiatry Management, P.O. Box 490, East Islip, NY 11730, (631) 563-1604 or e-mail us at [email protected]. Following this article, an answer sheet and full set of instructions are provided (p. 170 ).— Editor By Mark A Caselli, DPM claw deformity in 1829, and Cruveil - EEC was first described by Eckholdt hier first used the term “lobster-claw” and Martins in 1804. The clinical ctrodactyly, by strict definition, in 1842. Pedal ectrodactyly may exist manifestations of ectodermal dyspla - is the congenital absence of all or as a unilateral or bilateral deformity sia include cutaneous alterations (dry, Eany part of a digit. The term ec - in many combinations with other de - thin, hyperkeratotic skin), trichodys - trodactyly originates from the Greek formities (Figure 2). It may be present plasia (thin, sparse hair with little pig - ektroma (abortion) and daktylos (fin - as an isolated deformity or simulta - mentation), onychodysplasia (brittle ger). The term is also applied to cleft neously with similar defects in the and dysplastic nails), dental anomalies foot, lobster foot, and crab-claw foot. In hand. It most frequently presents as (small or absent teeth with excessive ectrodactyly, one or more toes and part of a defect syndrome, including caries), and dyshidrosis (sweating dys - parts of their metatarsals are usually ab - defects of the eye, palate, audition, function). The cleft lip may or may sent. The first and fifth rays are usually and abnormalities of the kidneys. not be accompanied by a cleft palate. present (Figure 1). If a metatarsal is par - Defects in other locations may also tially or completely absent, its respec - Associated Syndromes be associated with the classical EEC tive toe is always absent. The incidence Several syndromes have been asso - triad, such as the eyes, including defects of cleft foot is 1:90,000 live births. Ec - ciated with ectrodactyly. One of the in the nasolacrimal duct, entropion, trodactyly was first documented in most common is the EEC syndrome telecanthus, trichiasis, absent lashes,and 1770 among a tribe of Guiana Indians. consisting of ectodermal dysplasia, ec - meibomian gland disfunction, manifest - Von Walther described the crab- trodactyly, and cleft lip and palate. Continued on page 166 www.podiatrym.com JANUARY 2009 • PODIATRY MANAGEMENT 165 n g o in ti u a n c ti u Ectrodactyly... n d o E C al ic ing as blephoritis, corneal scar - d e ring, recurrent erosions, ble - M pharospasm, dry eye, and photophobia. Genitourinary system defects include hypospadias, hydronephrosis, renal age - nesis, and renal duplicity. Both deafness and mental retardation are also associat - ed with EEC syndrome. The clinical ex - pression of the defects associated with EEC is very diverse, ectodermal dysplasia Figure 2: Patient exhibiting ectrodactyly occurring 100%, lachrymal duct alter - deformity of the right foot and multiple ations 70-96.5%, ectrodactyly 78-88%, Figure 1: A classic presentation of pedal syndactilizations of the left foot. ectrodactyly. cleft lip/palate 58-88%, urinary alter - ations 15-55%, deafness 8-28%, and lidimide syndrome and Nager acrofa - mental retardation 1-16%. The inci - cial dysostosis; the fourth digit in con - dence of EEC is 1:190,000 live births. genital hypothalamic hamartoblas - toma polydactyly syndrome. Tripha - Other Syndromes langeal thumbs have been associated Other syndromes associated with ec - with ectrodactyly in a rare autosomal trodactyly include Carpenter’s syn - dominant syndrome. The combina - drome (acrocephalopolysyndactyly type tion of polydactyly and oligodactyly II), DeLange syndrome (multiple con - has been observed with both genetic genital anomaly/mental retardation and teratogen induced malformations (MCA/MR) disorder), Goltz syndrome in experimental animals. Figure 4: Postsurgical correction of ec - trodactyly. Presurgically, the corrected (focal dermal hypoplasia (FDH) disor - In Thalidomide embryopathy, the foot was too wide to fit into shoes. der), Jarcho Levine syndrome (spondy - polydactyly always occurs on the lothoracic dysplasia (STD) and spondy - hands with a reductional abnormality The anomaly was also seen in the locostal dysostosis (SCD) disorder), and involving the feet. Autosomal reces - Talaunda tribe from eastern Zimbabwe Miller syndrome (post-axial acrofacial sive syndromes involving ectrodacty - and Botswana. The Talaunda migrated dysostosis). Raas-Rothschild, et al. de - ly have been described in a closed is - from eastern Zimbabwe and may have scribed a syndrome of ectrodactyly, land population in Japan and in Mid - been of the same origins as the Wado - short stature, mental retardation, sen - dle Eastern cultures where marriage ma. In 1979, a magazine reported a sorineural deafness and abnormal faces. between first cousins is encouraged. group of at least 100 “ostrich footed” Limb-reducing defects that can be men. Recent studies have found three associated with ectrodactyly include Embryology and Genetics families of affected individuals among aplasia and hypoplasia of the tibia or these tribes and concluded that the pre - fibula (i.e., Volkmann syndrome). This Ectrodactyly in Africa vious tales of hundreds of ostrich-footed distal extremity reduction may occur In 1770, Jan Jacob Hartnick, a direc - persons belong in the realm of fantasy. concurrently with normal formation of tor of the Dutch East India Company, the proximal limb segment. Ectrodacty - made a reference to a touvinga or two- Embryology ly has also been found in patients with fingered tribe from Dutch Guyana in Human limbs develop from interac - aplasia cutis congenital and epidermol - South America. They were slaves who tions between limb ectoderm and ysis bullosa. Pedal ectrodactyly, without exhibited ectrodactyly, brought over mesoderm. An important embryonic similar upper extremity deficits, occurs from Central Africa. In the 1960’s, news - somite-somatopleural relationship pre - in 10% to 50% of cases of trisomy.(18) papers published interviews with unim - cedes the emergence of the limb bud Syndromes involving both poly - peachable witnesses who saw the phe - during the fourth week of gestation. dactyly and ectrodactyly have been nomenon in Africa. Gelfland, et al., in The lower limb buds develop as lateral described with the same digit usually 1974 investigated a Wadoma tribesman thickenings of the somatopleure. At the involved (absence or duplication); the from the Zambezi valley of Zimbabwe. fifth week, vertebrate limb buds develop thumb in Fanconi anemia, Tha - He was diagnosed as having “lobster a thickened epithelium at their distal claw” defor - tips. This apical ectodermal ridge (AER) mity of both functions as a principle inducer of axial feet. Two of limb elongation. The AER is required for his cousins progressive specification of mesodermal were affect - limb parts and promotion of axial ed and the growth through influencing cell divi - condition sion. The ridge also protects subridge was thought mesodermal cells from necrosis during to be auto - the active period of limb development. somal domi - The deep midline cleft, character - Figure 3: Blauth and Borisch radiological classification of pedal ectrodactyly. nant. Continued on page 167 166 PODIATRY MANAGEMENT • JANUARY 2009 www.podiatrym.com M C e o d n i t excess of afflicted male offspring metatarsals (Figure 3). ca in Ectrodactyly... l u Ed in through paternal transmission. In one Grade I: Five completely u g c istic of ectrodactyly, is caused by the study, a Pakistani kindred comprising normal metatarsals. Total or par - at io absence of one or more rays and toes. seven generations and 36 members with tial aplasia of toes 2 to 5, but usual - n The cleft formation begins at the 2nd the split-hand/split-foot anomaly, the ly with the involvement of toes 2 and or 3rd ray and proceeds from the dis - full expression of the trait, monodacty - 3.