- Email: [email protected]
Prenatal assessment of foot deformity
Early Human Development (2005) 81, 793 — 796
www.elsevier.com/locate/earlhumdev
REVIEW
Prenatal assessment of foot deformity Matthew Barry * The Royal London Hospital, London E1 1BB, UK
KEYWORDS Talipes; Ultrasound; Prenatal diagnosis
Abstract Congenital talipes equinovarus (CTEV) and other skeletal abnormalities can be diagnosed prenatally by ultrasound scan. If diagnosed, clinicians should be cautiously optimistic with the parents, particularly if the talipes diagnosed is isolated and not associated with other foetal abnormalities. There is no correlation between the prenatal appearance of the foot and the state of the foot at birth, nor with the necessity for surgical intervention. D 2005 Elsevier Ireland Ltd. All rights reserved.
Contents 1.
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1. What is CTEV? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2. Prenatal assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . 2. Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1. Embryological development of the limbs [2,3]. . . . . . . . . . . . . 2.2. Timing of scans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3. Incidence of talipes on USS . . . . . . . . . . . . . . . . . . . . . . . 2.4. Associated anomalies . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5. Amniocentesis — is it indicated? . . . . . . . . . . . . . . . . . . . . . 2.6. Correlation between prenatal diagnosis and post-natal appearance. 3. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1. Introduction With advances in ultrasound scan (USS) technology, an increasing amount of anatomical detail of the foetus is now becoming available. Recent
* Tel.: +44 20 7377 7445; fax: +44 20 7377 7302. E-mail address: [email protected].
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793 794 794 794 794 794 794 795 795 796 796 796
developments such as 3D scanning further enhance the quality of the images obtained. Anomaly scans are now routine and foot abnormalities are increasingly being identified on these scans. A wide variety of musculoskeletal disorders can be identified on these scans, including spinal abnormalities such as spina bifida or hemivertebrae, limb reduction abnormalities such as proximal femoral focal deficiency or finger abnormalities
0378-3782/$ - see front matter D 2005 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.earlhumdev.2005.06.013
794 such as polydactyly. A common deformity that is receiving much attention with regard to prenatal diagnosis is CTEV.
1.1. What is CTEV? Congenital talipes equinovarus is a structural deformity of the lower leg characterised clinically by a combination of a high heel (equinus) and inward tilting of the hindfoot (varus). There are associated deformities of the forefoot that are now generally considered to represent an excessive pronation of the first ray with a variable degree of cavus. In addition the calf may be hypoplastic. Spontaneous improvement does not occur, and treatment , although generally successful, is prolonged and may involve surgery. This structural anomaly may appear superficially similar to postural deformities commonly seen after birth. These latter deformities are related to intra-uterine position and may be part of a bpackagingQ problem. Spontaneous resolution is the rule, and no active treatment is generally required. Differentiation between these two superficially similar entities is therefore of extreme importance.
M. Barry from the vaginal canal) and by about 17—18 weeks of gestation, the TAS method is preferable.
2.1. Embryological development of the limbs [2,3] Limb buds appear at about week 4 of gestation, with the upper limb appearing a few days earlier than the lower limb. At week 5, the upper limb has started to develop distinct regions and by week 6, the hand rays have started to develop. By this time, the lower limb has developed a distinct thigh, lower leg and foot. By the seventh week, the finger and toe rays have started to develop and by 8—9 weeks, the toes and fingers have developed into separate digits. As the limb buds develop and grow, the limbs rotate. The upper limb externally rotates and the lower limb internally rotates. This results in the future elbow and knee being rotated by 1808 with respect to each other. This rotation is of prime importance in the genesis of the CTEV deformity. By weeks 10—11, the limb rotation process has finished and limb development is largely complete. Primary ossification centres start to be seen in most long bones diaphyses by week 12.
1.2. Prenatal assessment Currently, the only method of prenatal diagnosis of CTEV is by USS. Alternative imaging is not indicated. Plain radiographs and CT scans result in an unacceptably high dose of radiation to the developing foetus, and in addition, these imaging modalities do not show soft tissues well. Magnetic Resonance Imaging (MRI) may show foot abnormalities but at the present time, the effects of MRI on the developing foetus are not understood and therefore routine MRI scans are probably not justified.
2. Method Ultrasound scanning of the foetus can be performed either as a trans-abdominal scan (TAS) or a transvaginal scan (TVS). Early on in pregnancy, TVS results in better image resolution (the foetus is closer to the ultrasound probe) and as a result, musculoskeletal abnormalities can be detected earlier by the TVS method, skeletal abnormalities may be detected up to four weeks earlier [1] by the TVS method as compared to TAS. As the pregnancy proceeds, the TVS method becomes less useful (the foetus moves further away
2.2. Timing of scans The optimum time to perform an USS to detect CTEV is between weeks 14 and 16 [4] of gestation although in many centres, anomaly scans are not performed until 18—20 weeks [5,6]. Four types of talipes have been described [1] on USS: 1. Early onset — diagnosed at 14—16 weeks and includes most cases seen on USS. 2. Late onset — normal early scan but talipes noted at later scans after 20 weeks. (Many of these will not be true CTEV but will be simple positional deformities in a structurally normal foot.) 3. Transient talipes — initial abnormality disappears and a normal foot is seen at later scans. 4. Incomplete — some abnormalities noted on USS. About 5% of this type will go on and develop true CTEV.
2.3. Incidence of talipes on USS The incidence of CTEV at birth is about 1 per 1000 but there are racial variations, with, for example, up to 7 per 1000 births in the Maori population [4]. On USS, the incidence varies from 0.1% [7,8] to 0.4% [9].
Prenatal assessment of foot deformity
795
Figure 1 18 week USS of unilateral isolated talipes — dorsal view. Figure 3
The sensitivity and specificity of USS detection of talipes is not well reported in the literature. Tillett [6] reported a sensitivity of 0.95 (95% of affected feet were detected) but this paper was a small group of selected patients and was not a population survey. Other authors [9] have suggested that talipes associated with other abnormalities has a very low false positive rate (0%) but if the talipes is apparently isolated, the false positive rate is higher [9,10] especially if the USS is performed in the third trimester [1].
Appearance of foot at 10 days — plantar view.
diagnosed prenatally appeared to have an isolated finding of talipes. At birth, a significant number of these apparently isolated talipes cases had normal feet. However, in all cases of talipes associated with other abnormalities, talipes was present either at birth or termination. In other studies [7], up to 50% of talipes cases were associated with other abnormalities. It is likely that the talipes associated with other abnormalities may be a more severe bteratologicalQ club foot and so more easily seen on USS [1].
2.4. Associated anomalies 2.5. Amniocentesis — is it indicated? A variety of associated abnormalities have been noted [1,9]. Treadwell [9] found that in their study 67% of the cases of talipes identified prenatally had other abnormalities. These included CNS anomalies (36%), urogenital tract anomalies (29%) and skeletal dysplasias (10%). The remaining 33% of CTEV
Figure 2 18 week USS of unilateral isolated talipes — plantar view.
If an isolated abnormality is found, should an amniocentesis be performed to obtain a karyotype of the foetus? The literature is conflicting on this question.
Figure 4
Appearance of foot at 10 days — dorsal view.
796 Shipp and Benacerraf [10] argue that amniocentesis should be performed as in his paper, 6% of the isolated talipes cases had an abnormal karyotype. Pagnotta et al. [11] found that 22% of their cases had abnormal karyotypes although this included isolated talipes and talipes associated with other abnormalities on USS. In contrast, Malone et al. [12] found no abnormal karyotypes even in high risk mothers and therefore suggested that there was no indication for prenatal karyotyping, providing the USS was otherwise normal, apart from the talipes. Katz et al. [13] found no abnormal karyotypes, although the number of cases was small. As there appears to be a higher false positive rate in these isolated cases and the risks of an abnormal karyotype is low (6%) then amniocentesis is probably not indicated.
M. Barry positive rate appears to be low. This complex type of talipes is probably a more rigid teratological condition and may be associated with termination of the pregnancy. In these complex cases, amniocentesis may be indicated. However, in isolated cases of talipes with no other foetal abnormalities, then the indication for amniocentesis is less clear. When talipes is diagnosed as an isolated deformity, especially in the third trimester of pregnancy, the clinician should perhaps be more optimistic. A number of these feet may be normal at birth or have only a mild deformity requiring no treatment. Neither the appearance of the foot on ultrasound nor the stage of foetal development at which USS diagnosis is made, is strongly correlated with the true nature of the deformity at birth. This places limitations on the usefulness of prenatal counselling by the orthopaedic surgeon.
2.6. Correlation between prenatal diagnosis and post-natal appearance Once diagnosed, there is poor correlation between the prenatal appearance of the foot on USS and the severity of the talipes at birth [1,4,6]. Tillett et al. [6] noted that in 26% of the talipes diagnosed prenatally, the deformity was so mild at birth that no treatment was required. In their series, 13% were treated with serial casts and 61% required surgery. Kerat et al. [4] quoted a figure of 55% of prenatally diagnosed cases requiring surgery. Neither author could find any predictive factor in the prenatal diagnosis with respect to the likelihood of structural abnormality of the foot requiring treatment. Experience in our practice would support this observation, making meaningful prenatal counselling difficult. There is inevitably a risk of causing unnecessary concern for those prospective parents who find that their baby has nothing more than a positional talipes that does not require treatment. The most positive aspect of such counselling is that it raises awareness of the possibility of a true structural deformity that requires immediate treatment. Figs. 1 and 2 show an 18 week ultrasound scan of an isolated unilateral true CTEV. Figs. 3 and 4 are the same foot, ten days after birth and after one week in a plaster cast. In this case the foot was treated by casting and Achilles tenotomy, as described by Ponseti and Smoley [14].
3. Conclusion Talipes can be diagnosed prenatally and if associated with other foetal abnormalities, the false
References [1] Weintroub S, Keret D, Bronshtein M. Prenatal sonographic diagnosis of musculoskeletal disorders. J Paed Orth 1999;19:1 – 4. [2] http://nmhm.washingtondc.museum/collections/hdac/ index.htm. [3] http://www.visembryo.com. [4] Kerat D, Ezra F, Lokiec F, Hayek S, Segev E, Weintroub S. Efficacy of prenatal ultrasonography in confirmed club foot. J Bone Joint Surg 2002;84B:1015 – 9. [5] Burgan HE, Furness ME, Foster BK. Prenatal ultrasound diagnosis of clubfoot. J Paed Orth 1999;19:11 – 3. [6] Tillett RL, Fisk NM, Murphy K, Hunt DM. Clinical outcome of congenital talipes equinovarus diagnoses antenatally by ultrasound. J Bone Joint Surg 2000;82B:876 – 80. [7] Bakalis S, Sairam S, Homfray T, Harrington K, Nicolaides K, Thilaganathan B. Outcome of antenatally diagnosed talipes equinovarus in an unselected obstetric population. Ultrasound Obstet Gynecol 2002;20:226 – 9. [8] Rijhsinghani A, Yankowitz J, Kamis AB, Mueller GM, Yankowitz DK, Williamson RA. Antenatal sonographic diagnosis of club foot with particular attention to the implications and outcomes of isolated club foot. Ultrasound Obstet Gynecol 1998;12:103 – 6. [9] Treadwell MC, Stanitski C, King M. Prenatal sonographic diagnosis of club foot: implications for patient counselling. J Paed Orth 1999;19:8 – 10. [10] Shipp TD, Benacerraf BR. The significance of prenatally identified isolated clubfoot: is amniocentesis indicated. Am J Obstet Gynecol 1998;178:600 – 2. [11] Pagnotta G, Maffulli N, Aureli S, Maggi E, Mariani M, Yip KM. Antenatal sonographic diagnosis of clubfoot: a six-year experience. J Foot Ankle Surg 1996;35:67 – 71. [12] Malone FD, Marino T, Bianchi DW, Johnston K, D’Alton ME. Isolated clubfoot diagnosed prenatally: is karyotyping indicated? Obstet Gynecol 2000;95:437 – 40. [13] Katz K, Meizner I, Mashiach R, Soudry M. The contribution of prenatal sonographic diagnosis of clubfoot to preventive medicine. J Paed Orth 1999;19:5 – 7. [14] Ponseti IV, Smoley EN. Congenital club foot: the results of treatment. J Bone Joint Surg 1963;45A:261 – 5.
www.elsevier.com/locate/earlhumdev
REVIEW
Prenatal assessment of foot deformity Matthew Barry * The Royal London Hospital, London E1 1BB, UK
KEYWORDS Talipes; Ultrasound; Prenatal diagnosis
Abstract Congenital talipes equinovarus (CTEV) and other skeletal abnormalities can be diagnosed prenatally by ultrasound scan. If diagnosed, clinicians should be cautiously optimistic with the parents, particularly if the talipes diagnosed is isolated and not associated with other foetal abnormalities. There is no correlation between the prenatal appearance of the foot and the state of the foot at birth, nor with the necessity for surgical intervention. D 2005 Elsevier Ireland Ltd. All rights reserved.
Contents 1.
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1. What is CTEV? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2. Prenatal assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . 2. Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1. Embryological development of the limbs [2,3]. . . . . . . . . . . . . 2.2. Timing of scans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3. Incidence of talipes on USS . . . . . . . . . . . . . . . . . . . . . . . 2.4. Associated anomalies . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5. Amniocentesis — is it indicated? . . . . . . . . . . . . . . . . . . . . . 2.6. Correlation between prenatal diagnosis and post-natal appearance. 3. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1. Introduction With advances in ultrasound scan (USS) technology, an increasing amount of anatomical detail of the foetus is now becoming available. Recent
* Tel.: +44 20 7377 7445; fax: +44 20 7377 7302. E-mail address: [email protected].
. . . . . . . . . . . .
. . . . . . . . . . . .
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793 794 794 794 794 794 794 795 795 796 796 796
developments such as 3D scanning further enhance the quality of the images obtained. Anomaly scans are now routine and foot abnormalities are increasingly being identified on these scans. A wide variety of musculoskeletal disorders can be identified on these scans, including spinal abnormalities such as spina bifida or hemivertebrae, limb reduction abnormalities such as proximal femoral focal deficiency or finger abnormalities
0378-3782/$ - see front matter D 2005 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.earlhumdev.2005.06.013
794 such as polydactyly. A common deformity that is receiving much attention with regard to prenatal diagnosis is CTEV.
1.1. What is CTEV? Congenital talipes equinovarus is a structural deformity of the lower leg characterised clinically by a combination of a high heel (equinus) and inward tilting of the hindfoot (varus). There are associated deformities of the forefoot that are now generally considered to represent an excessive pronation of the first ray with a variable degree of cavus. In addition the calf may be hypoplastic. Spontaneous improvement does not occur, and treatment , although generally successful, is prolonged and may involve surgery. This structural anomaly may appear superficially similar to postural deformities commonly seen after birth. These latter deformities are related to intra-uterine position and may be part of a bpackagingQ problem. Spontaneous resolution is the rule, and no active treatment is generally required. Differentiation between these two superficially similar entities is therefore of extreme importance.
M. Barry from the vaginal canal) and by about 17—18 weeks of gestation, the TAS method is preferable.
2.1. Embryological development of the limbs [2,3] Limb buds appear at about week 4 of gestation, with the upper limb appearing a few days earlier than the lower limb. At week 5, the upper limb has started to develop distinct regions and by week 6, the hand rays have started to develop. By this time, the lower limb has developed a distinct thigh, lower leg and foot. By the seventh week, the finger and toe rays have started to develop and by 8—9 weeks, the toes and fingers have developed into separate digits. As the limb buds develop and grow, the limbs rotate. The upper limb externally rotates and the lower limb internally rotates. This results in the future elbow and knee being rotated by 1808 with respect to each other. This rotation is of prime importance in the genesis of the CTEV deformity. By weeks 10—11, the limb rotation process has finished and limb development is largely complete. Primary ossification centres start to be seen in most long bones diaphyses by week 12.
1.2. Prenatal assessment Currently, the only method of prenatal diagnosis of CTEV is by USS. Alternative imaging is not indicated. Plain radiographs and CT scans result in an unacceptably high dose of radiation to the developing foetus, and in addition, these imaging modalities do not show soft tissues well. Magnetic Resonance Imaging (MRI) may show foot abnormalities but at the present time, the effects of MRI on the developing foetus are not understood and therefore routine MRI scans are probably not justified.
2. Method Ultrasound scanning of the foetus can be performed either as a trans-abdominal scan (TAS) or a transvaginal scan (TVS). Early on in pregnancy, TVS results in better image resolution (the foetus is closer to the ultrasound probe) and as a result, musculoskeletal abnormalities can be detected earlier by the TVS method, skeletal abnormalities may be detected up to four weeks earlier [1] by the TVS method as compared to TAS. As the pregnancy proceeds, the TVS method becomes less useful (the foetus moves further away
2.2. Timing of scans The optimum time to perform an USS to detect CTEV is between weeks 14 and 16 [4] of gestation although in many centres, anomaly scans are not performed until 18—20 weeks [5,6]. Four types of talipes have been described [1] on USS: 1. Early onset — diagnosed at 14—16 weeks and includes most cases seen on USS. 2. Late onset — normal early scan but talipes noted at later scans after 20 weeks. (Many of these will not be true CTEV but will be simple positional deformities in a structurally normal foot.) 3. Transient talipes — initial abnormality disappears and a normal foot is seen at later scans. 4. Incomplete — some abnormalities noted on USS. About 5% of this type will go on and develop true CTEV.
2.3. Incidence of talipes on USS The incidence of CTEV at birth is about 1 per 1000 but there are racial variations, with, for example, up to 7 per 1000 births in the Maori population [4]. On USS, the incidence varies from 0.1% [7,8] to 0.4% [9].
Prenatal assessment of foot deformity
795
Figure 1 18 week USS of unilateral isolated talipes — dorsal view. Figure 3
The sensitivity and specificity of USS detection of talipes is not well reported in the literature. Tillett [6] reported a sensitivity of 0.95 (95% of affected feet were detected) but this paper was a small group of selected patients and was not a population survey. Other authors [9] have suggested that talipes associated with other abnormalities has a very low false positive rate (0%) but if the talipes is apparently isolated, the false positive rate is higher [9,10] especially if the USS is performed in the third trimester [1].
Appearance of foot at 10 days — plantar view.
diagnosed prenatally appeared to have an isolated finding of talipes. At birth, a significant number of these apparently isolated talipes cases had normal feet. However, in all cases of talipes associated with other abnormalities, talipes was present either at birth or termination. In other studies [7], up to 50% of talipes cases were associated with other abnormalities. It is likely that the talipes associated with other abnormalities may be a more severe bteratologicalQ club foot and so more easily seen on USS [1].
2.4. Associated anomalies 2.5. Amniocentesis — is it indicated? A variety of associated abnormalities have been noted [1,9]. Treadwell [9] found that in their study 67% of the cases of talipes identified prenatally had other abnormalities. These included CNS anomalies (36%), urogenital tract anomalies (29%) and skeletal dysplasias (10%). The remaining 33% of CTEV
Figure 2 18 week USS of unilateral isolated talipes — plantar view.
If an isolated abnormality is found, should an amniocentesis be performed to obtain a karyotype of the foetus? The literature is conflicting on this question.
Figure 4
Appearance of foot at 10 days — dorsal view.
796 Shipp and Benacerraf [10] argue that amniocentesis should be performed as in his paper, 6% of the isolated talipes cases had an abnormal karyotype. Pagnotta et al. [11] found that 22% of their cases had abnormal karyotypes although this included isolated talipes and talipes associated with other abnormalities on USS. In contrast, Malone et al. [12] found no abnormal karyotypes even in high risk mothers and therefore suggested that there was no indication for prenatal karyotyping, providing the USS was otherwise normal, apart from the talipes. Katz et al. [13] found no abnormal karyotypes, although the number of cases was small. As there appears to be a higher false positive rate in these isolated cases and the risks of an abnormal karyotype is low (6%) then amniocentesis is probably not indicated.
M. Barry positive rate appears to be low. This complex type of talipes is probably a more rigid teratological condition and may be associated with termination of the pregnancy. In these complex cases, amniocentesis may be indicated. However, in isolated cases of talipes with no other foetal abnormalities, then the indication for amniocentesis is less clear. When talipes is diagnosed as an isolated deformity, especially in the third trimester of pregnancy, the clinician should perhaps be more optimistic. A number of these feet may be normal at birth or have only a mild deformity requiring no treatment. Neither the appearance of the foot on ultrasound nor the stage of foetal development at which USS diagnosis is made, is strongly correlated with the true nature of the deformity at birth. This places limitations on the usefulness of prenatal counselling by the orthopaedic surgeon.
2.6. Correlation between prenatal diagnosis and post-natal appearance Once diagnosed, there is poor correlation between the prenatal appearance of the foot on USS and the severity of the talipes at birth [1,4,6]. Tillett et al. [6] noted that in 26% of the talipes diagnosed prenatally, the deformity was so mild at birth that no treatment was required. In their series, 13% were treated with serial casts and 61% required surgery. Kerat et al. [4] quoted a figure of 55% of prenatally diagnosed cases requiring surgery. Neither author could find any predictive factor in the prenatal diagnosis with respect to the likelihood of structural abnormality of the foot requiring treatment. Experience in our practice would support this observation, making meaningful prenatal counselling difficult. There is inevitably a risk of causing unnecessary concern for those prospective parents who find that their baby has nothing more than a positional talipes that does not require treatment. The most positive aspect of such counselling is that it raises awareness of the possibility of a true structural deformity that requires immediate treatment. Figs. 1 and 2 show an 18 week ultrasound scan of an isolated unilateral true CTEV. Figs. 3 and 4 are the same foot, ten days after birth and after one week in a plaster cast. In this case the foot was treated by casting and Achilles tenotomy, as described by Ponseti and Smoley [14].
3. Conclusion Talipes can be diagnosed prenatally and if associated with other foetal abnormalities, the false
References [1] Weintroub S, Keret D, Bronshtein M. Prenatal sonographic diagnosis of musculoskeletal disorders. J Paed Orth 1999;19:1 – 4. [2] http://nmhm.washingtondc.museum/collections/hdac/ index.htm. [3] http://www.visembryo.com. [4] Kerat D, Ezra F, Lokiec F, Hayek S, Segev E, Weintroub S. Efficacy of prenatal ultrasonography in confirmed club foot. J Bone Joint Surg 2002;84B:1015 – 9. [5] Burgan HE, Furness ME, Foster BK. Prenatal ultrasound diagnosis of clubfoot. J Paed Orth 1999;19:11 – 3. [6] Tillett RL, Fisk NM, Murphy K, Hunt DM. Clinical outcome of congenital talipes equinovarus diagnoses antenatally by ultrasound. J Bone Joint Surg 2000;82B:876 – 80. [7] Bakalis S, Sairam S, Homfray T, Harrington K, Nicolaides K, Thilaganathan B. Outcome of antenatally diagnosed talipes equinovarus in an unselected obstetric population. Ultrasound Obstet Gynecol 2002;20:226 – 9. [8] Rijhsinghani A, Yankowitz J, Kamis AB, Mueller GM, Yankowitz DK, Williamson RA. Antenatal sonographic diagnosis of club foot with particular attention to the implications and outcomes of isolated club foot. Ultrasound Obstet Gynecol 1998;12:103 – 6. [9] Treadwell MC, Stanitski C, King M. Prenatal sonographic diagnosis of club foot: implications for patient counselling. J Paed Orth 1999;19:8 – 10. [10] Shipp TD, Benacerraf BR. The significance of prenatally identified isolated clubfoot: is amniocentesis indicated. Am J Obstet Gynecol 1998;178:600 – 2. [11] Pagnotta G, Maffulli N, Aureli S, Maggi E, Mariani M, Yip KM. Antenatal sonographic diagnosis of clubfoot: a six-year experience. J Foot Ankle Surg 1996;35:67 – 71. [12] Malone FD, Marino T, Bianchi DW, Johnston K, D’Alton ME. Isolated clubfoot diagnosed prenatally: is karyotyping indicated? Obstet Gynecol 2000;95:437 – 40. [13] Katz K, Meizner I, Mashiach R, Soudry M. The contribution of prenatal sonographic diagnosis of clubfoot to preventive medicine. J Paed Orth 1999;19:5 – 7. [14] Ponseti IV, Smoley EN. Congenital club foot: the results of treatment. J Bone Joint Surg 1963;45A:261 – 5.