SEARCH

SEARCH BY CITATION

Keywords:

  • congenital anomaly;
  • curly toe;
  • digital anomaly;
  • prenatal ultrasound;
  • ultrasound

Abstract

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Acknowledgements
  8. References

Objectives

To assess the prevalence, prenatal detection rate, and associated anomalies of congenital curly toe in an unselected obstetric population.

Methods

Between September 2001 and July 2002, 1167 singleton fetuses in the second and third trimesters underwent routine prenatal ultrasound at our hospital. Congenital curly toe was diagnosed when the fourth or fifth toe was not fully delineated on the axial image with medial and plantar flexion on the coronal image. All neonates underwent a physical examination within 3 days after delivery. Radiography was performed on those infants with curly toe. We assessed the prevalence, prenatal detection rate, and associated anomalies of the condition.

Results

There were 38 congenital curly toes among the 1167 neonates, yielding a total prevalence of 32.6 per 1000. In 26 of the 38 the fourth toe was curly and in 12 the fifth toe was curly. Of those in which the fourth toe was curly, 26.9% involved the right toe, 65.4% the left, and 7.7% involved both toes. For a curly fifth toe, these values were 25.0%, 16.7% and 58.3%, respectively. There was no associated structural anomaly, chromosomal abnormality, or syndrome in any case. Sixteen of the 38 curly toes were detected on prenatal ultrasound, including 13 of 26 with the fourth toe being curly and three of 12 with the fifth being curly.

Conclusions

Congenital curly toe is not an uncommon condition, and can be detected on the prenatal ultrasound. Although it usually appears as an isolated finding without clinical significance, thorough ultrasound examination of the fetus should be recommended. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.


Introduction

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Acknowledgements
  8. References

Congenital curly toe is a deformity most commonly involving the fourth and fifth toes. It is also known as underlapping or varus toe. The affected toe deviates in a plantar and medial direction and usually has a varus rotation at the level of the distal interphalangeal joint1–5.

In routine fetal ultrasound, it is common to find that the fourth or fifth toe is not fully delineated on the axial image of the fetal foot, which may mimic more serious conditions, such as amputation or overlapping of the toe. In the case of a congenital curly toe, the underlapping of the fourth or fifth toe with medial and plantar flexion can be observed. Although congenital curly toe is a common deformity in postnatal life, to our knowledge there has been no report of its prenatal diagnosis and the prevalence and associated anomalies have not been established. The purpose of this study, therefore, was to assess the prevalence, prenatal detection rate and associated anomalies of congenital curly toe in an unselected obstetric population.

Methods

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Acknowledgements
  8. References

Between September 2001 and July 2002, 1167 singleton fetuses underwent routine prenatal ultrasound at our hospital in the second (19–24 weeks) and third (30–36 weeks) trimesters and were enrolled into this prospective study. Examinations were performed using LOGIQ 400 (GE Medical systems, Milwaukee, WI, USA) and Ultramark 9-HDI (Advanced Technology Laboratories, Bothell, WA, USA) ultrasound machines. Curly toe was diagnosed on the axial and coronal images of the fetal foot when the following criteria were satisfied: (1) there was mild shortening of the fourth or fifth toe on the axial image; (2) the toe deviated in a plantar and medial direction on the coronal image (Figures 1 and 2); (3) these findings remained consistent during the examination. To evaluate associated fetal anomalies, we performed detailed ultrasound evaluation of the fetuses, including biometric studies. All neonates underwent physical examination by a neonatologist within 3 days after birth and radiographic examination was performed in cases of congenital curly toe.

thumbnail image

Figure 1. Ultrasound image showing a curly fourth toe at 32 weeks' gestation: on the axial image (a) the toe is not fully delineated (arrow) and on the coronal image (b) it is deviated in a plantar and medial direction.

Download figure to PowerPoint

thumbnail image

Figure 2. Ultrasound image showing a curly fifth toe at 35 weeks' gestation: on the axial image (a) the toe is not well delineated (arrow) and on the coronal image (b) it is deviated in a plantar and medial direction (thin arrow).

Download figure to PowerPoint

Prenatal ultrasound findings were compared with postnatal results. We divided the neonates with curly toes into six groups on the basis of which toes were affected (right fourth toe; left fourth toe; bilateral fourth toes; right fifth toe; left fifth toe; bilateral fifth toes) and assessed the prevalence of curly toe in each group. We also evaluated the prenatal detection rate and the associated structural anomalies and chromosomal abnormalities.

Results

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Acknowledgements
  8. References

Thirty-eight cases with congenital curly toe were detected among the 1167 neonates, yielding a total prevalence of 32.6 per 1000. In 26 of the 38 neonates (68.4%) the fourth toe was curly and in 12 (31.6%) the fifth toe was curly. Table 1 shows the prevalence of right, left or bilateral curly toes. There was no case of combined fourth and fifth curly toes.

Table 1. Prevalence of types of congenital curly toe
 Right (n (%))Left (n (%))Bilateral (n (%))
Curly fourth toe (n = 26)7 (26.9)17 (65.4)2 (7.7)
Curly fifth toe (n = 12)3 (25.0)2 (16.7)7 (58.3)
Total (n = 38)10 (26.3)19 (50.0)9 (23.7)

Sixteen of the 38 (42.1%) curly toes were detected on prenatal ultrasound 13 of the 26 (50.0%) with a curly fourth toe and three (25.0%) of the 12 with a curly fifth toe (Table 2).

Table 2. Detection rates of congenital curly toe
ClassificationDetected on ultrasound (n (%))Undetected on ultrasound (n (%))
2ndtrimester3rdtrimester
Curly fourth toe (n = 26)8 (30.8)5 (19.2)13 (50.0)
Curly fifth toe (n = 12)0 (0.0)3 (25.0)9 (75.0)
Total (n = 38)16 (42.1)22 (57.9)

There was no associated structural anomaly in any affected fetus on prenatal ultrasound or postnatal examination. Although chromosomal studies were not performed, there was no evidence of chromosomal abnormality on postnatal examination. There was no evidence of underlying bone defects on the radiographic images of the affected feet in all neonates (Figure 3).

thumbnail image

Figure 3. Postnatal photograph (a) of congenital curly fourth toe showing medial and plantar deviation of the toe (arrow) in the right foot. Radiography (b) revealed no definite evidence of bone abnormality.

Download figure to PowerPoint

Discussion

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Acknowledgements
  8. References

Congenital curly toe is a generalized term used to describe a common congenital occurrence in which one or more of the lesser toes deviate medially under the adjacent toe. The affected toe abnormally flexes in a plantar and medial direction, and shows a varus rotation usually at the level of the distal interphalangeal joint. It usually occurs bilaterally and symmetrically and has a high familial incidence1, 2. We did not assess the familial tendency in our cases, but there were several cases in which the parents or siblings of the fetuses also had congenital curly toe.

The majority of minor digital anomalies are associated with chromosomal abnormalities or other fetal syndromes. Fetuses with trisomy 13 may have postaxial polydactyly of the hands or feet6. Fetuses with trisomy 18 have characteristically clenched hands, with overlapping fingers7. Fetuses with triploidy usually have syndactyly8. Fetuses with Down syndrome may have clinodactyly and a wide space between the big toe and the second toe9, 10. There has been no report about anomalies associated with congenital curly toe, and we found no associated structural anomaly, chromosomal abnormality or syndrome in all babies in this study. However, further large-series studies will be necessary to establish whether there is an association of congenital curly toe with other anomalies.

Treatment of congenital curly toe varies with the degree of deformity. If the deformity remains flexible and asymptomatic, treatment is not necessary1, 4, 5, 11–13. According to Sweetnam14, congenital curly toe usually resolves spontaneously by the age of 6 years. However, if the deformity is symptomatic and conservative treatment fails, surgery is indicated1, 11, 15–17. In our cases, no baby underwent any kind of treatment.

Although usually congenital curly toe resolves spontaneously, it is important to distinguish it from other minor digital anomalies such as overlapping or amputation of digits, both of which may be confused with congenital curly toe on prenatal ultrasound. Unlike congenital curly toe, overlapping toe may be associated with other congenital anomalies or syndromes18–20 and early treatment may be necessary21. Amputation of a digit usually results from the amniotic bands sticking, tangling, and disrupting the fetal part22, which suggests an amniotic band syndrome.

The overall prenatal detection rate of congenital curly toe was not high in our study; the detection rate of curly fifth toes was very low. We think this may be as a result of the difficulty in distinguishing a curly fifth toe from compression of the fifth toe by the adjacent fetal part or the maternal uterine wall. However, with care and familiarity with its prenatal ultrasound characteristics, the detection rate may be increased.

In conclusion, congenital curly toe is not an uncommon anomaly of the fetus. It can be detected on prenatal ultrasound and usually appears as an isolated finding without clinical significance. However, thorough ultrasound examination of the fetus is mandatory for the differential diagnosis of this anomaly from the other digit anomalies which usually appear as manifestations in a complex anomaly or syndrome.

Acknowledgements

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Acknowledgements
  8. References

We especially thank our colleagues, Jee Young Lee, Soo Young Lee, Kwang Won Kim and Eun Jung Park, for their great help in this study.

References

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Acknowledgements
  8. References
  • 1
    McDaniel L, Tafuri SA. Congenital digital deformities. Clin Pediatr Med Surg 1996; 13: 327342.
  • 2
    Bouchard JL. Congenital deformities of the forefoot. In Comprehensive Textbook of Foot Surgery, vol. I, McGlamryE (ed). Williams & Wilkins: Baltimore, 1987.
  • 3
    Tachdjian M. The foot and leg. In Pediatric Orthopedics, TachdjianM (ed). W.B. Saunders: Philadelphia, 1990.
  • 4
    Boc SF, Martone JD. Varus toes: a review and case report. J Foot Ankle Surg 1995; 34: 220222.
  • 5
    Reinherz RP. Editorial. J Foot Surg 1991; 30: 429430.
  • 6
    Benacerraf BR, Miller WA, Frigoletto FD Jr. Sonographic detection of fetuses with trisomies 13 and 18: accuracy and limitation. Am J Obstet Gynecol 1988; 158: 404409.
  • 7
    Bundy AL, Saltzman DH, Pober B, Fine C, Emerson D, Doubilet PM. Antenatal sonographic findings in trisomy 18. J Ultrasound Med 1986; 5: 361364.
  • 8
    Crane JP, Beaver HA, Cheung SW. Antenatal ultrasound findings in fetal triploidy syndrome. J Ultrasound Med 1985; 4: 519524.
  • 9
    Benacerraf BR, Harlow BL, Frigoletto FD Jr. Hypoplasia of the middle phalanx of the fifth digit: a feature of the second trimester fetus with Down syndrome. J Ultrasound Med 1990; 9: 389394.
  • 10
    Wilkins I. Separation of the great toe in fetuses with Down syndrome. J Ultrasound Med 1994; 13: 229231.
  • 11
    Fixsen JA. Problem feet in children. J R Soc Med 1998; 91: 1822.
  • 12
    Ross ERS, Menelaus MB. Open flexor tenotomy for hammer toes and curly toes in childhood. J Bone Joint Surg Br 1984; 66: 770771.
  • 13
    Turner PL. Strapping of curly toes in children. Aust N Z J Surg 1987; 57: 467470.
  • 14
    Sweetnam R. Congenital curly toes: an investigation into the value of treatment. Lancet 1958; 23: 398400.
  • 15
    Pollard JP, Morrison PJ. Flexor tenotomy in the treatment of curly toes. Proc R Soc Med 1975; 68: 480481.
  • 16
    Biyani A, Jones DA, Murray JM. Flexor to extensor tendon transfer for curly toes. 43 children reviewed after 8 (1–25) years. Acta Orthop Scand 1992; 63: 451454.
  • 17
    Hamer AJ, Stanley D, Smith TW. Surgery for curly toe deformity: a double-blind, randomised, prospective trial. J Bone Joint Surg Br 1993; 75: 662663.
  • 18
    Erickson CM, Hirschberger M, Stickler GB. Carpal-tarsal osteolysis. J Pediatr 1978; 93: 779782.
  • 19
    Lohr H, Wiedemann HR. Mesomelic dysplasia-associated with other abnormalities. Eur J Pediatr 1981; 137: 313316.
  • 20
    Stoll C, Alembik Y, Repetto M. Congenital bilateral fibular deficiency with facial dysmorphia, brachydactyly and mental retardation in a girl. Genet Couns 1998; 9: 147152.
  • 21
    Huurman WW. Congenital foot deformities. In Surgery of the Foot (5th edn), MannRA (ed). Mosby: St. Louis, 1986.
  • 22
    Angtuaco TL. Fetal anterior abdominal wall defect. In Ultrasonography in Obstetrics and Gynecology (4th edn), CallenPW (ed). W.B. Saunders: Philadelphia, 2000.