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BY
T HE J OURNAL
OF
B ONE
AND J OINT
S URGERY, I NCORPORATED
Walking Age of Infants with Idiopathic Clubfoot Treated Using the Ponseti Method Lewis E. Zionts, MD, Davida F. Packer, MD, Shannon Cooper, BS, Edward Ebramzadeh, PhD, and Sophia Sangiorgio, PhD Investigation performed at the Orthopaedic Institute for Children, Los Angeles, California
Background: The Ponseti method is an established approach to treating idiopathic clubfoot in infants. The method involves a period of cast immobilization and postcorrective bracing that potentially interferes with normal movements of the lower extremities. In the present study, we investigated the age at which infants who had idiopathic clubfoot treated using the Ponseti method achieved independent walking. Methods: We prospectively evaluated patients of a single surgeon. Included in the study were all patients with idiopathic clubfoot who were full term at birth, were no more than twelve weeks of age at the start of treatment, had received no prior outside treatment, and were followed for a minimum of twenty-four months. Results: Ninety-four patients were included. The mean age at which patients began walking independently was 14.5 ± 2.6 months (range, ten to twenty-two months). By eighteen months, 90% of the patients were walking without assistance. Patients with moderate or severe clubfoot deformity began walking earlier than did patients with very severe deformity (a mean of 14.2 months compared with 15.8 months; p = 0.03). Patients who experienced a relapse before learning to walk began walking later than those who did not relapse (a mean of 15.9 months compared with 14.2 months; p = 0.04). Other patient and treatment-related variables had no significant influence on the onset of walking. Conclusions: On the basis of our findings, parents of infants with idiopathic clubfoot treated using the Ponseti method may expect their child to achieve independent walking approximately two months later than infants without clubfoot deformity. A greater delay may be expected for those patients who have a very severe deformity or those who experience a deformity relapse. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
Peer Review: This article was reviewed by the Editor-in-Chief and one Deputy Editor, and it underwent blinded review by two or more outside experts. It was also reviewed by an expert in methodology and statistics. The Deputy Editor reviewed each revision of the article, and it underwent a final review by the Editor-in-Chief prior to publication. Final corrections and clarifications occurred during one or more exchanges between the author(s) and copyeditors.
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he Ponseti method is a well-established and widely accepted approach to treating idiopathic clubfoot in infants1-5. The technique involves a series of specific manipulations and cast applications to correct the forefoot, midfoot, and subtalar components of the deformity. A percutaneous Achilles (heel-cord) tenotomy is usually required to address any remaining equinus and provide final correction of the foot. After the foot is corrected, a foot abduction orthosis is used to prevent a relapse of the deformity. This device is worn full time for three months and then at night and at naptime until the child is at least four years old.
At the start of treatment, many parents express concern over whether this treatment method will affect the motor development of their child, most notably the achievement of independent walking. Two recent studies have suggested that the start of walking may be delayed in infants with idiopathic clubfoot managed using the Ponseti method6,7. Both of these investigations had limitations imposed by their small sample size. Garcia et al.6 observed twenty-six infants with idiopathic clubfoot, only twelve of whom were treated using the Ponseti method. Sala et al.7 noted a delay in the achievement of independent walking in thirty-six patients whose clubfoot was managed using
Disclosure: None of the authors received payments or services, either directly or indirectly (i.e., via his or her institution), from a third party in support of any aspect of this work. None of the authors, or their institution(s), have had any financial relationship, in the thirty-six months prior to submission of this work, with any entity in the biomedical arena that could be perceived to influence or have the potential to influence what is written in this work. Also, no author has had any other relationships, or has engaged in any other activities, that could be perceived to influence or have the potential to influence what is written in this work. The complete Disclosures of Potential Conflicts of Interest submitted by authors are always provided with the online version of the article.
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TABLE I Influence of Patient Factors on Achievement of Independent Walking No. of Patients (%)
Age at Walking* (mo)
P Value†
Total patient population
94 (100%)
14.5 ± 2.6
N/A
Sex Male Female
68 (72%) 26 (28%)
14.3 ± 2.7 15.1 ± 2.5
0.17
Bilaterality Yes No
50 (53%) 44 (47%)
14.2 ± 2.6 14.9 ± 2.6
0.23
Deformity classification (Dim´eglio) Moderate or severe (5-14 points) Very severe (‡15 points)
76 (81%) 18 (19%)
14.2 ± 2.5 15.8 ± 2.8
Family history of clubfoot Yes No
22 (23%) 72 (77%)
14.4 ± 2.8 14.5 ± 2.6
0.03 0.89
*Values are presented as the mean and standard deviation. †N/A = not applicable.
the Ponseti technique. The authors noted that they did not have a sufficient number of patients to evaluate the effect of other variables, such as unilateral or bilateral involvement. The purpose of the present study was to determine, with use of a prospective, single-surgeon database, the age at which infants with idiopathic clubfoot treated with the Ponseti method begin to walk. We also evaluated the influence of other factors, such as sex, bilaterality, severity of deformity, and early relapse, on the achievement of independent walking. Materials and Methods
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his study was approved by the institutional review board of the University of California, Los Angeles. We invited families of infants who had been diagnosed with idiopathic clubfoot and were initially seen at our clinic between July 2006 and August 2011 to participate in this prospective study. Exclusion criteria included a gestational age of less than thirty-seven weeks, an age of more than twelve weeks at the start of treatment, prior outside treatment, mild or positional deformity, or orthopaedic problems other than clubfoot that might affect motor development. We also excluded patients who were lost to followup prior to reaching twenty-four months of follow-up at our institution. The severity of the foot deformity was graded at initial presentation by 8 the senior author (L.E.Z.) using the Dim´eglio scale , a classification scheme 9 with very good interobserver relability . Feet were classified into one of four categories: Grade I (0 to 4 points, mild), Grade II (5 to 9 points, moderate), Grade III (10 to 14 points, severe), and Grade IV (15 to 20 points, very severe). For infants with bilateral clubfoot, the greater of the two Dim´eglio scores was used for the analysis. Infants with a mild deformity (Grade I) were excluded because the treatment of these feet was usually less extensive and often differed from the standard Ponseti method. The feet were manipulated at weekly intervals as prescribed by the Ponseti 2 method . The cavus, adductus, and varus components of the deformity were corrected by positioning the foot in supination and then abducting the foot while counter pressure was applied with the thumb over the head of the talus. We applied casts using semi-rigid fiberglass material (3M Scotchcast Soft Cast Casting Tape; 3M, St. Paul, Minnesota). When the foot achieved 70° of abduction relative to the thigh, a heel-cord tenotomy was deemed indicated if there was less than 15° of dorsiflexion. Tenotomies were performed in the operating room with the 10 patient under sedation, after which a cast was worn for three weeks .
After the last cast was removed, the infants were fitted with a Mitchell11 Ponseti (MP) brace (MD Orthopaedics, Wayland, Iowa) . The parents were instructed to apply the brace for twenty-three hours a day for three months, followed by use at night and at naptime. In general, we instructed the parents to perform heel-cord stretching exercises on the child before applying the brace. None of the infants had any formal physical therapy prior to walking. In general, once use of the brace began, the patients were followed at three-month intervals. At each visit, the parents were interviewed to determine whether, and when, the patient had begun to walk independently. The validity of the parental report was supported by observation of the infant by the physician during the clinic visit. The parental report was deemed valid if the physician observed the infant taking ten or more steps without assistance. The age at which walking began was recorded to the nearest month. Other data collected included patient age, sex, side of involvement, family history of clubfoot, number of casts needed to obtain initial correction, need for heel-cord tenotomy, noncompliance with bracing, and early relapse of deformity. For the purposes of the present study, noncompliance with bracing was defined as failure to use the brace as prescribed. Relapse was defined as the reappearance of any of the components of the clubfoot deformity requiring further treatment.
Data Analysis power analysis was conducted to determine the sample size required to detect a difference of one month or greater between patients with idiopathic clubfoot and otherwise healthy infants in terms of a delay in walking age. A standard deviation (SD) of 2.2 months, reported in a recent study7 that investigated the age at which patients with idiopathic clubfoot achieve gross motor milestones, was used for this analysis. Given a power of 80% and with a = 0.05, we estimated that seventy-seven patients in each group would be sufficient to detect a difference of one month or greater. As previous studies have examined the age at walking for healthy patients with the use of much larger sample sizes (816 to 3554 patients)12-14, a control group of children without clubfoot was not included. Independent sample t tests were performed to quantify the certainty (p value) associated with each of the observed differences in the mean age at walking as influenced by patient
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Fig. 1
Patient inclusion and exclusion criteria.
variables and treatment variables. The patient variables included in the analysis were sex, bilaterality, family history of clubfoot, and the severity of deformity. The treatment variables included were the number of casts needed prior to tenotomy, the need for tenotomy, noncompliance with brace use, and relapse of deformity. In addition, the Spearman correlation coefficient was used to determine the strength of correlation, if any, between age at walking and weeks of casting. In addition to the analysis above, the available data from the twelve patients who did not complete twenty-four months of clinical follow-up and therefore were excluded from the analysis were compared with the data from the included patients, to determine any differences in terms of Dime´ glio scores, demographic characteristics, and, if available, age at walking and outcome variables, such as relapse. Source of Funding No external source of funding was obtained for this study. Results ne hundred and seventy consecutive infants with a diagnosis of idiopathic clubfoot were initially seen at the Orthopaedic Institute for Children Clubfoot Clinic between July 2006 and August 2011. Of the 154 patients for whom consent was obtained, ninety-four met the inclusion criteria and were
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followed for a minimum of two years. These patients formed the study group (Fig. 1). The mean duration of follow-up (and SD) was 43.8 ± 14.6 months (range, 24 to 75.9 months). Sixty-eight (72%) of the patients were male, and fifty (53%) of the patients had bilateral involvement. Among those with unilateral deformity, the left foot was affected in twentyfive (57%) of the cases. Twenty-two (23%) of the ninety-four patients had a first-degree relative with clubfoot. Deformity was classified as Dime´ glio Grade II (moderate) or Grade III (severe) for seventy-six (81%) of the patients and Grade IV (very severe) for eighteen (19%) of the patients. The mean age at which treatment began was 4.1 ± 2.4 weeks (range, 0.7 to 11.7 weeks). The mean number of casts that were applied before the tenotomy was 5.5 (range, three to twelve casts). Eighty-nine (95%) of the patients underwent a heel-cord tenotomy. Initial correction of the deformity was achieved in all patients. The families of twenty-one (22%) of the patients were noncompliant with bracing prior to the onset of walking. Fourteen (15%) of the patients had a deformity relapse, which was managed with a series of one to three manipulations and casts, followed by the resumption of bracing. The mean age at which patients began to walk independently was 14.5 ± 2.6 months (range, ten to twenty-two months). Table I shows the influence of the patient variables studied on the mean age at walking. Table II shows the influence of treatment
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TABLE II Influence of Treatment Factors on Achievement of Independent Walking No. of Patients (%)
Age at Walking* (mo)
P Value
Noncompliance with brace use prior to walking Yes No
21 (22%) 73 (78%)
14.9 ± 2.7 14.4 ± 2.6
0.41
Relapse prior to walking Yes No
14 (15%) 80 (85%)
15.9 ± 2.6 14.2 ± 2.6
0.04
Heel-cord tenotomy Yes No
89 (95%) 5 (5%)
14.5 ± 2.6 14.0 ± 2.6
0.69
Number of casts £4 5 or 6 ‡7
22 (23%) 57 (61%) 15 (16%)
14.5 ± 2.4 14.5 ± 2.6 14.5 ± 3.1
0.99
*Values are presented as the mean and standard deviation.
factors (noncompliance with brace use prior to the onset of walking, relapse prior to walking, the need for heel-cord tenotomy, and the number of casts) on the mean age at walking. Overall, the patient factor that had the greatest influence on the mean age at walking was the severity of deformity (Fig. 2, Table I). For the purposes of analyzing the data and comparing for significance, due to the limited number of patients (eight) with Grade-II (moderate) deformity, the Grade-II and Grade-III patients were combined, as was done in a previous study11. We found that patients with an initial diagnosis of a moderate or severe clubfoot deformity began walking more than one month sooner than the patients whose deformity was classified as very severe (14.2 months compared with 15.8 months; p = 0.03). The male patients tended to walk slightly earlier (0.8 months earlier) than the female patients, but this trend was not significant (p = 0.17). A family history of clubfoot appeared to have the least influence on the age at which patients began to walk (p = 0.89) (Table I). Of the treatment factors, the occurrence of a relapse prior to walking was the most influential factor. Patients who experienced a relapse before learning to walk began walking nearly two months later than those who did not relapse (15.9 months compared with 14.2 months; p = 0.04) (Table II). The number of casts used prior to tenotomy, the need for heel-cord tenotomy, and noncompliance with brace use did not significantly influence the age at which patients began to walk. In the present study, slightly more than 50% of the patients (forty-nine) had achieved walking by fourteen months of age, regardless of severity of deformity, relapse, sex, or any other patient or treatment-related factor. By 16.5 months, seventy-one (75%) of the patients were walking, and by eighteen months, eighty-five (90%) of the patients were walking (Table III). The characteristics of the twelve patients who met the inclusion criteria but who did not complete twenty-four months
of follow-up were similar to those of the patients who were included in the study. The mean duration of follow-up was 15.8 ± 5.5 months; three patients were known to have moved. Ten of the patients were classified as having severe deformity and two, very severe, on the basis of the Dime´ glio scale. All patients underwent heel-cord tenotomy, and the mean number of casts prior to tenotomy was 5.6 ± 1.7. During the known follow-up period, eight patients had been noted to have brace noncompliance and, of those eight, four relapsed prior to being
Fig. 2
Boxplots represent the age at which patients began to walk as a function of deformity severity. The median is represented by the thick band within each box, and the top and bottom of the box represent the 25th and 75th percentiles. The whiskers represent the high and low values, excluding outliers between 1.5 and 3.0-box lengths from the median. The circle at the top of the figure represents an outlier.
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TABLE III Comparison with Previous Reports of Infants without Deformity on Achievement of Walking* Present Study
13
Denver II (Frankenberg et al.)
12
WHO Multicenter
14
Neligan and Prudham
Total no. of patients
94
2096
816
3554
Age at walking (mo) Mean ± SD 50% of patients 75% of patients 90% of patients
14.5 ± 2.6 14.0 16.5 18.0
NR 12.3 13.6 14.9
12.1 ± 1.8 12.0 13.1 14.4
NR 12.8 14.2 15.8
*NR = not reported.
lost. Walking age was reported for five of the patients, a mean of 13.8 ± 1.3 months. Discussion arents often perceive normalcy during their infant’s first year of life based on when independent walking is achieved15. The reported mean age at which otherwise healthy infants begin to walk has ranged from 11.7 to 12.8 months12-16. The present study found that, among infants with idiopathic clubfoot managed using the Ponseti method, the mean age at which unassisted walking began was 14.5 months (range, ten to twenty-two months). We found that 50% of patients were walking by 14.0 months of age and 90% were walking by 18.0 months. In contrast, in a study of 816 healthy patients, the World Health Organization (WHO)12 reported a mean walking age of 12.1 ± 1.8 months, with 50% of the patients walking at 12.0 months (Table III). The difference in mean age between that of our study and the WHO study (2.4 months) was significant (p < 0.0001). The authors of two other studies have reported the distribution in walking age for healthy subjects13,14. Although these studies did not present the mean and standard deviation, on the basis of our power analysis and estimations, the patients with clubfoot in our study walked, on average, 1.2 to two months later than the healthy subjects of those studies (p < 0.0001). This finding agrees with that of two other studies that found that infants with idiopathic clubfoot, treated using the Ponseti method, may begin to walk approximately two months later than the walking age reported for healthy infants6,7. Garcia et al.6 used the Alberta Infant Motor Scale (AIMS) when comparing the gross motor performance of a group of twenty-six infants treated for idiopathic clubfoot using the Ponseti technique (twelve infants), French physical therapy method (nine infants), or both (five infants), with that of a group of twenty-six normally developing infants. While they found no difference in gross motor development between the groups at three and six months, the AIMS scores for the infants with clubfoot were lower at nine and twelve months than the scores of the infants in the other group. Also, the percentage of infants who were not yet walking at twelve months was greater in the clubfoot group (81%) than in the normal group (48%). The authors reported
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that the mean age at walking was 13.9 months for the clubfoot group. The authors acknowledged that the significance of their findings was limited by the small sample size. In a more recent study, Sala et al.7 evaluated the acquisition of gross motor milestones in thirty-six infants with idiopathic clubfoot treated using the Ponseti method. They reported that the mean age of independent walking was 13.9 months, which was approximately two months later than that reported in two studies of normally developing infants. These authors noted that they did not have a sufficient number of patients to evaluate the effect of other variables, such as unilateral or bilateral involvement. The mean age at walking in the present study was higher than that reported by Sala et al.7 (14.5 months compared with 13.9 months). This difference may be due to our inclusion of patients who experienced an early relapse. In the present study, patients who did not experience an early relapse walked at a mean of 14.2 months. We evaluated several patient variables that might affect the age at which our patients began to walk (Table I). We found no significant influence of sex, bilaterality, or a family history of clubfoot. Similarly, Garcia et al.6 found no significant difference between infants with bilateral clubfoot and unilateral clubfoot in terms of AIMS scores at any of the assessment intervals in their study. Our patients who were initially classified as having a very severe deformity, based on the Dime´ glio classification, achieved independent walking more than one month later than those patients who had a moderate or severe deformity. This finding contrasts with that of Garcia et al.6, who concluded that the severity of the deformity at initial presentation, also assessed with use of the Dime´ glio score, did not influence the attainment of motor skills. Among the treatment variables we evaluated (Table II), the number of casts applied prior to tenotomy, the need for a heel-cord tenotomy, and noncompliance with the brace protocol had no significant influence on the age at which the patients began walking. However, infants who experienced an early relapse of the deformity began walking at an average of 1.7 months later than those patients who did not experience a relapse. This finding may be attributable to the need for additional cast applications and increased time in the postcorrective brace that was
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required to regain and maintain correction of the feet in these patients. Perhaps most importantly, this finding underscores the importance of achieving and maintaining a complete correction to the attainment of independent walking as early as possible. The reason why infants with idiopathic clubfoot walk later than other children is subject to speculation. Garcia et al.6 suggested that early constraints on movement of the lower extremities imposed by the use of casts and splints may lead to alterations in balance or the strength of certain muscle groups. They also hypothesized that the presence of clubfoot may be a marker for an underlying mild dysfunction in motor development. The validity of the results of this study is limited by the accuracy of the parent’s report as to when their infant began to walk. Majnemer and Rosenblatt17 examined the consistency of a parent’s memory of developmental milestones. They found that the mean discrepancy in parental recall of their infant’s first steps was less than 0.4 months at three and five years after the occurrence. We expect that the parental reporting of infant age at walking in the present study was accurate, because the frequent follow-up intervals allowed for nearly concurrent observation by the physician. In conclusion, and on the basis of our findings, the parents of infants who have idiopathic clubfoot deformity
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treated with use of the Ponseti method should generally expect their child to achieve independent walking approximately two months later than infants without clubfoot deformity. This finding does not appear to be affected by sex, bilaterality, a family history of clubfoot, the number of casts required, or the need for tenotomy. However, a greater delay may be expected for patients with a very severe deformity or for those who experience a relapse of the deformity. n NOTE: The authors thank Jennifer Hall, BS, who assisted in the collection of data for this study.
Lewis E. Zionts, MD Shannon Cooper, BS Edward Ebramzadeh, PhD Sophia Sangiorgio, PhD Orthopaedic Institute for Children, 403 West Adams Boulevard, Los Angeles, CA 90007. E-mail address: [email protected] Davida F. Packer, MD Department of Orthopaedics, Miami Children’s Hospital, 3100 S.W. 62nd Avenue, Miami FL 33155
References 1. Morcuende JA, Dolan LA, Dietz FR, Ponseti IV. Radical reduction in the rate of extensive corrective surgery for clubfoot using the Ponseti method. Pediatrics. 2004 Feb;113(2):376-80. 2. Ponseti IV. Congenital clubfoot. Fundamentals of treatment. New York: Oxford University Press; 1996. 3. Ponseti IV, Smoley EN. Congenital clubfoot: the results of treatment. J Bone Joint Surg Am. 1963;45:261-75. 4. Zionts LE, Sangiorgio SN, Ebramzadeh E, Morcuende JA. The current management of idiopathic clubfoot revisited: results of a survey of the POSNA membership. J Pediatr Orthop. 2012 Jul-Aug;32(5):515-20. 5. Zionts LE, Zhao G, Hitchcock K, Maewal J, Ebramzadeh E. Has the rate of extensive surgery to treat idiopathic clubfoot declined in the United States? J Bone Joint Surg Am. 2010 Apr;92(4):882-9. 6. Garcia NL, McMulkin ML, Tompkins BJ, Caskey PM, Mader SL, Baird GO. Gross motor development in babies with treated idiopathic clubfoot. Pediatr Phys Ther. 2011 Winter;23(4):347-52. 7. Sala DA, Chu A, Lehman WB, van Bosse HJ. Achievement of gross motor milestones in children with idiopathic clubfoot treated with the Ponseti method. J Pediatr Orthop. 2013 Jan;33(1):55-8. 8. Dim´eglio A, Bensahel H, Souchet P, Mazeau P, Bonnet F. Classification of clubfoot. J Pediatr Orthop B. 1995;4(2):129-36. 9. Flynn JM, Donohoe M, Mackenzie WG. An independent assessment of two clubfoot-classification systems. J Pediatr Orthop. 1998 May-Jun;18(3):323-7.
10. Iravani M, Chalabi J, Kim R, Ebramzadeh E, Zionts LE. Propofol sedation for infants with idiopathic clubfoot undergoing percutaneous tendoachilles tenotomy. J Pediatr Orthop. 2013 Jan;33(1):59-62. 11. Zionts LE, Frost N, Kim R, Ebramzadeh E, Sangiorgio SN. Treatment of idiopathic clubfoot: experience with the Mitchell-Ponseti brace. J Pediatr Orthop. 2012 Oct-Nov;32(7):706-13. 12. WHO Multicentre Growth Reference Study Group. WHO Motor Development Study: windows of achievement for six gross motor development milestones. Acta Paediatr Suppl. 2006 Apr;450:86-95. 13. Frankenberg W, Dodds J, Archer P, Bresnick B, Maschka P, Edelman N, Shapiro H. The DENVER II training manual. Denver: Denver Developmental Materials, Inc.; 1992. 14. Neligan G, Prudham D. Norms for four standard developmental milestones by sex, social class and place in family. Dev Med Child Neurol. 1969 Aug;11(4):413-22. 15. Davis BE, Moon RY, Sachs HC, Ottolini MC. Effects of sleep position on infant motor development. Pediatrics. 1998 Nov;102(5): 1135-40. 16. Capute AJ, Shapiro BK, Palmer FB, Ross A, Wachtel RC. Normal gross motor development: the influences of race, sex and socio-economic status. Dev Med Child Neurol. 1985 Oct;27(5):635-43. 17. Majnemer A, Rosenblatt B. Reliability of parental recall of developmental milestones. Pediatr Neurol. 1994 Jun;10(4):304-8.
BY
T HE J OURNAL
OF
B ONE
AND J OINT
S URGERY, I NCORPORATED
Walking Age of Infants with Idiopathic Clubfoot Treated Using the Ponseti Method Lewis E. Zionts, MD, Davida F. Packer, MD, Shannon Cooper, BS, Edward Ebramzadeh, PhD, and Sophia Sangiorgio, PhD Investigation performed at the Orthopaedic Institute for Children, Los Angeles, California
Background: The Ponseti method is an established approach to treating idiopathic clubfoot in infants. The method involves a period of cast immobilization and postcorrective bracing that potentially interferes with normal movements of the lower extremities. In the present study, we investigated the age at which infants who had idiopathic clubfoot treated using the Ponseti method achieved independent walking. Methods: We prospectively evaluated patients of a single surgeon. Included in the study were all patients with idiopathic clubfoot who were full term at birth, were no more than twelve weeks of age at the start of treatment, had received no prior outside treatment, and were followed for a minimum of twenty-four months. Results: Ninety-four patients were included. The mean age at which patients began walking independently was 14.5 ± 2.6 months (range, ten to twenty-two months). By eighteen months, 90% of the patients were walking without assistance. Patients with moderate or severe clubfoot deformity began walking earlier than did patients with very severe deformity (a mean of 14.2 months compared with 15.8 months; p = 0.03). Patients who experienced a relapse before learning to walk began walking later than those who did not relapse (a mean of 15.9 months compared with 14.2 months; p = 0.04). Other patient and treatment-related variables had no significant influence on the onset of walking. Conclusions: On the basis of our findings, parents of infants with idiopathic clubfoot treated using the Ponseti method may expect their child to achieve independent walking approximately two months later than infants without clubfoot deformity. A greater delay may be expected for those patients who have a very severe deformity or those who experience a deformity relapse. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
Peer Review: This article was reviewed by the Editor-in-Chief and one Deputy Editor, and it underwent blinded review by two or more outside experts. It was also reviewed by an expert in methodology and statistics. The Deputy Editor reviewed each revision of the article, and it underwent a final review by the Editor-in-Chief prior to publication. Final corrections and clarifications occurred during one or more exchanges between the author(s) and copyeditors.
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he Ponseti method is a well-established and widely accepted approach to treating idiopathic clubfoot in infants1-5. The technique involves a series of specific manipulations and cast applications to correct the forefoot, midfoot, and subtalar components of the deformity. A percutaneous Achilles (heel-cord) tenotomy is usually required to address any remaining equinus and provide final correction of the foot. After the foot is corrected, a foot abduction orthosis is used to prevent a relapse of the deformity. This device is worn full time for three months and then at night and at naptime until the child is at least four years old.
At the start of treatment, many parents express concern over whether this treatment method will affect the motor development of their child, most notably the achievement of independent walking. Two recent studies have suggested that the start of walking may be delayed in infants with idiopathic clubfoot managed using the Ponseti method6,7. Both of these investigations had limitations imposed by their small sample size. Garcia et al.6 observed twenty-six infants with idiopathic clubfoot, only twelve of whom were treated using the Ponseti method. Sala et al.7 noted a delay in the achievement of independent walking in thirty-six patients whose clubfoot was managed using
Disclosure: None of the authors received payments or services, either directly or indirectly (i.e., via his or her institution), from a third party in support of any aspect of this work. None of the authors, or their institution(s), have had any financial relationship, in the thirty-six months prior to submission of this work, with any entity in the biomedical arena that could be perceived to influence or have the potential to influence what is written in this work. Also, no author has had any other relationships, or has engaged in any other activities, that could be perceived to influence or have the potential to influence what is written in this work. The complete Disclosures of Potential Conflicts of Interest submitted by authors are always provided with the online version of the article.
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http://dx.doi.org/10.2106/JBJS.M.01525
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TABLE I Influence of Patient Factors on Achievement of Independent Walking No. of Patients (%)
Age at Walking* (mo)
P Value†
Total patient population
94 (100%)
14.5 ± 2.6
N/A
Sex Male Female
68 (72%) 26 (28%)
14.3 ± 2.7 15.1 ± 2.5
0.17
Bilaterality Yes No
50 (53%) 44 (47%)
14.2 ± 2.6 14.9 ± 2.6
0.23
Deformity classification (Dim´eglio) Moderate or severe (5-14 points) Very severe (‡15 points)
76 (81%) 18 (19%)
14.2 ± 2.5 15.8 ± 2.8
Family history of clubfoot Yes No
22 (23%) 72 (77%)
14.4 ± 2.8 14.5 ± 2.6
0.03 0.89
*Values are presented as the mean and standard deviation. †N/A = not applicable.
the Ponseti technique. The authors noted that they did not have a sufficient number of patients to evaluate the effect of other variables, such as unilateral or bilateral involvement. The purpose of the present study was to determine, with use of a prospective, single-surgeon database, the age at which infants with idiopathic clubfoot treated with the Ponseti method begin to walk. We also evaluated the influence of other factors, such as sex, bilaterality, severity of deformity, and early relapse, on the achievement of independent walking. Materials and Methods
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his study was approved by the institutional review board of the University of California, Los Angeles. We invited families of infants who had been diagnosed with idiopathic clubfoot and were initially seen at our clinic between July 2006 and August 2011 to participate in this prospective study. Exclusion criteria included a gestational age of less than thirty-seven weeks, an age of more than twelve weeks at the start of treatment, prior outside treatment, mild or positional deformity, or orthopaedic problems other than clubfoot that might affect motor development. We also excluded patients who were lost to followup prior to reaching twenty-four months of follow-up at our institution. The severity of the foot deformity was graded at initial presentation by 8 the senior author (L.E.Z.) using the Dim´eglio scale , a classification scheme 9 with very good interobserver relability . Feet were classified into one of four categories: Grade I (0 to 4 points, mild), Grade II (5 to 9 points, moderate), Grade III (10 to 14 points, severe), and Grade IV (15 to 20 points, very severe). For infants with bilateral clubfoot, the greater of the two Dim´eglio scores was used for the analysis. Infants with a mild deformity (Grade I) were excluded because the treatment of these feet was usually less extensive and often differed from the standard Ponseti method. The feet were manipulated at weekly intervals as prescribed by the Ponseti 2 method . The cavus, adductus, and varus components of the deformity were corrected by positioning the foot in supination and then abducting the foot while counter pressure was applied with the thumb over the head of the talus. We applied casts using semi-rigid fiberglass material (3M Scotchcast Soft Cast Casting Tape; 3M, St. Paul, Minnesota). When the foot achieved 70° of abduction relative to the thigh, a heel-cord tenotomy was deemed indicated if there was less than 15° of dorsiflexion. Tenotomies were performed in the operating room with the 10 patient under sedation, after which a cast was worn for three weeks .
After the last cast was removed, the infants were fitted with a Mitchell11 Ponseti (MP) brace (MD Orthopaedics, Wayland, Iowa) . The parents were instructed to apply the brace for twenty-three hours a day for three months, followed by use at night and at naptime. In general, we instructed the parents to perform heel-cord stretching exercises on the child before applying the brace. None of the infants had any formal physical therapy prior to walking. In general, once use of the brace began, the patients were followed at three-month intervals. At each visit, the parents were interviewed to determine whether, and when, the patient had begun to walk independently. The validity of the parental report was supported by observation of the infant by the physician during the clinic visit. The parental report was deemed valid if the physician observed the infant taking ten or more steps without assistance. The age at which walking began was recorded to the nearest month. Other data collected included patient age, sex, side of involvement, family history of clubfoot, number of casts needed to obtain initial correction, need for heel-cord tenotomy, noncompliance with bracing, and early relapse of deformity. For the purposes of the present study, noncompliance with bracing was defined as failure to use the brace as prescribed. Relapse was defined as the reappearance of any of the components of the clubfoot deformity requiring further treatment.
Data Analysis power analysis was conducted to determine the sample size required to detect a difference of one month or greater between patients with idiopathic clubfoot and otherwise healthy infants in terms of a delay in walking age. A standard deviation (SD) of 2.2 months, reported in a recent study7 that investigated the age at which patients with idiopathic clubfoot achieve gross motor milestones, was used for this analysis. Given a power of 80% and with a = 0.05, we estimated that seventy-seven patients in each group would be sufficient to detect a difference of one month or greater. As previous studies have examined the age at walking for healthy patients with the use of much larger sample sizes (816 to 3554 patients)12-14, a control group of children without clubfoot was not included. Independent sample t tests were performed to quantify the certainty (p value) associated with each of the observed differences in the mean age at walking as influenced by patient
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Fig. 1
Patient inclusion and exclusion criteria.
variables and treatment variables. The patient variables included in the analysis were sex, bilaterality, family history of clubfoot, and the severity of deformity. The treatment variables included were the number of casts needed prior to tenotomy, the need for tenotomy, noncompliance with brace use, and relapse of deformity. In addition, the Spearman correlation coefficient was used to determine the strength of correlation, if any, between age at walking and weeks of casting. In addition to the analysis above, the available data from the twelve patients who did not complete twenty-four months of clinical follow-up and therefore were excluded from the analysis were compared with the data from the included patients, to determine any differences in terms of Dime´ glio scores, demographic characteristics, and, if available, age at walking and outcome variables, such as relapse. Source of Funding No external source of funding was obtained for this study. Results ne hundred and seventy consecutive infants with a diagnosis of idiopathic clubfoot were initially seen at the Orthopaedic Institute for Children Clubfoot Clinic between July 2006 and August 2011. Of the 154 patients for whom consent was obtained, ninety-four met the inclusion criteria and were
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followed for a minimum of two years. These patients formed the study group (Fig. 1). The mean duration of follow-up (and SD) was 43.8 ± 14.6 months (range, 24 to 75.9 months). Sixty-eight (72%) of the patients were male, and fifty (53%) of the patients had bilateral involvement. Among those with unilateral deformity, the left foot was affected in twentyfive (57%) of the cases. Twenty-two (23%) of the ninety-four patients had a first-degree relative with clubfoot. Deformity was classified as Dime´ glio Grade II (moderate) or Grade III (severe) for seventy-six (81%) of the patients and Grade IV (very severe) for eighteen (19%) of the patients. The mean age at which treatment began was 4.1 ± 2.4 weeks (range, 0.7 to 11.7 weeks). The mean number of casts that were applied before the tenotomy was 5.5 (range, three to twelve casts). Eighty-nine (95%) of the patients underwent a heel-cord tenotomy. Initial correction of the deformity was achieved in all patients. The families of twenty-one (22%) of the patients were noncompliant with bracing prior to the onset of walking. Fourteen (15%) of the patients had a deformity relapse, which was managed with a series of one to three manipulations and casts, followed by the resumption of bracing. The mean age at which patients began to walk independently was 14.5 ± 2.6 months (range, ten to twenty-two months). Table I shows the influence of the patient variables studied on the mean age at walking. Table II shows the influence of treatment
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TABLE II Influence of Treatment Factors on Achievement of Independent Walking No. of Patients (%)
Age at Walking* (mo)
P Value
Noncompliance with brace use prior to walking Yes No
21 (22%) 73 (78%)
14.9 ± 2.7 14.4 ± 2.6
0.41
Relapse prior to walking Yes No
14 (15%) 80 (85%)
15.9 ± 2.6 14.2 ± 2.6
0.04
Heel-cord tenotomy Yes No
89 (95%) 5 (5%)
14.5 ± 2.6 14.0 ± 2.6
0.69
Number of casts £4 5 or 6 ‡7
22 (23%) 57 (61%) 15 (16%)
14.5 ± 2.4 14.5 ± 2.6 14.5 ± 3.1
0.99
*Values are presented as the mean and standard deviation.
factors (noncompliance with brace use prior to the onset of walking, relapse prior to walking, the need for heel-cord tenotomy, and the number of casts) on the mean age at walking. Overall, the patient factor that had the greatest influence on the mean age at walking was the severity of deformity (Fig. 2, Table I). For the purposes of analyzing the data and comparing for significance, due to the limited number of patients (eight) with Grade-II (moderate) deformity, the Grade-II and Grade-III patients were combined, as was done in a previous study11. We found that patients with an initial diagnosis of a moderate or severe clubfoot deformity began walking more than one month sooner than the patients whose deformity was classified as very severe (14.2 months compared with 15.8 months; p = 0.03). The male patients tended to walk slightly earlier (0.8 months earlier) than the female patients, but this trend was not significant (p = 0.17). A family history of clubfoot appeared to have the least influence on the age at which patients began to walk (p = 0.89) (Table I). Of the treatment factors, the occurrence of a relapse prior to walking was the most influential factor. Patients who experienced a relapse before learning to walk began walking nearly two months later than those who did not relapse (15.9 months compared with 14.2 months; p = 0.04) (Table II). The number of casts used prior to tenotomy, the need for heel-cord tenotomy, and noncompliance with brace use did not significantly influence the age at which patients began to walk. In the present study, slightly more than 50% of the patients (forty-nine) had achieved walking by fourteen months of age, regardless of severity of deformity, relapse, sex, or any other patient or treatment-related factor. By 16.5 months, seventy-one (75%) of the patients were walking, and by eighteen months, eighty-five (90%) of the patients were walking (Table III). The characteristics of the twelve patients who met the inclusion criteria but who did not complete twenty-four months
of follow-up were similar to those of the patients who were included in the study. The mean duration of follow-up was 15.8 ± 5.5 months; three patients were known to have moved. Ten of the patients were classified as having severe deformity and two, very severe, on the basis of the Dime´ glio scale. All patients underwent heel-cord tenotomy, and the mean number of casts prior to tenotomy was 5.6 ± 1.7. During the known follow-up period, eight patients had been noted to have brace noncompliance and, of those eight, four relapsed prior to being
Fig. 2
Boxplots represent the age at which patients began to walk as a function of deformity severity. The median is represented by the thick band within each box, and the top and bottom of the box represent the 25th and 75th percentiles. The whiskers represent the high and low values, excluding outliers between 1.5 and 3.0-box lengths from the median. The circle at the top of the figure represents an outlier.
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TABLE III Comparison with Previous Reports of Infants without Deformity on Achievement of Walking* Present Study
13
Denver II (Frankenberg et al.)
12
WHO Multicenter
14
Neligan and Prudham
Total no. of patients
94
2096
816
3554
Age at walking (mo) Mean ± SD 50% of patients 75% of patients 90% of patients
14.5 ± 2.6 14.0 16.5 18.0
NR 12.3 13.6 14.9
12.1 ± 1.8 12.0 13.1 14.4
NR 12.8 14.2 15.8
*NR = not reported.
lost. Walking age was reported for five of the patients, a mean of 13.8 ± 1.3 months. Discussion arents often perceive normalcy during their infant’s first year of life based on when independent walking is achieved15. The reported mean age at which otherwise healthy infants begin to walk has ranged from 11.7 to 12.8 months12-16. The present study found that, among infants with idiopathic clubfoot managed using the Ponseti method, the mean age at which unassisted walking began was 14.5 months (range, ten to twenty-two months). We found that 50% of patients were walking by 14.0 months of age and 90% were walking by 18.0 months. In contrast, in a study of 816 healthy patients, the World Health Organization (WHO)12 reported a mean walking age of 12.1 ± 1.8 months, with 50% of the patients walking at 12.0 months (Table III). The difference in mean age between that of our study and the WHO study (2.4 months) was significant (p < 0.0001). The authors of two other studies have reported the distribution in walking age for healthy subjects13,14. Although these studies did not present the mean and standard deviation, on the basis of our power analysis and estimations, the patients with clubfoot in our study walked, on average, 1.2 to two months later than the healthy subjects of those studies (p < 0.0001). This finding agrees with that of two other studies that found that infants with idiopathic clubfoot, treated using the Ponseti method, may begin to walk approximately two months later than the walking age reported for healthy infants6,7. Garcia et al.6 used the Alberta Infant Motor Scale (AIMS) when comparing the gross motor performance of a group of twenty-six infants treated for idiopathic clubfoot using the Ponseti technique (twelve infants), French physical therapy method (nine infants), or both (five infants), with that of a group of twenty-six normally developing infants. While they found no difference in gross motor development between the groups at three and six months, the AIMS scores for the infants with clubfoot were lower at nine and twelve months than the scores of the infants in the other group. Also, the percentage of infants who were not yet walking at twelve months was greater in the clubfoot group (81%) than in the normal group (48%). The authors reported
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that the mean age at walking was 13.9 months for the clubfoot group. The authors acknowledged that the significance of their findings was limited by the small sample size. In a more recent study, Sala et al.7 evaluated the acquisition of gross motor milestones in thirty-six infants with idiopathic clubfoot treated using the Ponseti method. They reported that the mean age of independent walking was 13.9 months, which was approximately two months later than that reported in two studies of normally developing infants. These authors noted that they did not have a sufficient number of patients to evaluate the effect of other variables, such as unilateral or bilateral involvement. The mean age at walking in the present study was higher than that reported by Sala et al.7 (14.5 months compared with 13.9 months). This difference may be due to our inclusion of patients who experienced an early relapse. In the present study, patients who did not experience an early relapse walked at a mean of 14.2 months. We evaluated several patient variables that might affect the age at which our patients began to walk (Table I). We found no significant influence of sex, bilaterality, or a family history of clubfoot. Similarly, Garcia et al.6 found no significant difference between infants with bilateral clubfoot and unilateral clubfoot in terms of AIMS scores at any of the assessment intervals in their study. Our patients who were initially classified as having a very severe deformity, based on the Dime´ glio classification, achieved independent walking more than one month later than those patients who had a moderate or severe deformity. This finding contrasts with that of Garcia et al.6, who concluded that the severity of the deformity at initial presentation, also assessed with use of the Dime´ glio score, did not influence the attainment of motor skills. Among the treatment variables we evaluated (Table II), the number of casts applied prior to tenotomy, the need for a heel-cord tenotomy, and noncompliance with the brace protocol had no significant influence on the age at which the patients began walking. However, infants who experienced an early relapse of the deformity began walking at an average of 1.7 months later than those patients who did not experience a relapse. This finding may be attributable to the need for additional cast applications and increased time in the postcorrective brace that was
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required to regain and maintain correction of the feet in these patients. Perhaps most importantly, this finding underscores the importance of achieving and maintaining a complete correction to the attainment of independent walking as early as possible. The reason why infants with idiopathic clubfoot walk later than other children is subject to speculation. Garcia et al.6 suggested that early constraints on movement of the lower extremities imposed by the use of casts and splints may lead to alterations in balance or the strength of certain muscle groups. They also hypothesized that the presence of clubfoot may be a marker for an underlying mild dysfunction in motor development. The validity of the results of this study is limited by the accuracy of the parent’s report as to when their infant began to walk. Majnemer and Rosenblatt17 examined the consistency of a parent’s memory of developmental milestones. They found that the mean discrepancy in parental recall of their infant’s first steps was less than 0.4 months at three and five years after the occurrence. We expect that the parental reporting of infant age at walking in the present study was accurate, because the frequent follow-up intervals allowed for nearly concurrent observation by the physician. In conclusion, and on the basis of our findings, the parents of infants who have idiopathic clubfoot deformity
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treated with use of the Ponseti method should generally expect their child to achieve independent walking approximately two months later than infants without clubfoot deformity. This finding does not appear to be affected by sex, bilaterality, a family history of clubfoot, the number of casts required, or the need for tenotomy. However, a greater delay may be expected for patients with a very severe deformity or for those who experience a relapse of the deformity. n NOTE: The authors thank Jennifer Hall, BS, who assisted in the collection of data for this study.
Lewis E. Zionts, MD Shannon Cooper, BS Edward Ebramzadeh, PhD Sophia Sangiorgio, PhD Orthopaedic Institute for Children, 403 West Adams Boulevard, Los Angeles, CA 90007. E-mail address: [email protected] Davida F. Packer, MD Department of Orthopaedics, Miami Children’s Hospital, 3100 S.W. 62nd Avenue, Miami FL 33155
References 1. Morcuende JA, Dolan LA, Dietz FR, Ponseti IV. Radical reduction in the rate of extensive corrective surgery for clubfoot using the Ponseti method. Pediatrics. 2004 Feb;113(2):376-80. 2. Ponseti IV. Congenital clubfoot. Fundamentals of treatment. New York: Oxford University Press; 1996. 3. Ponseti IV, Smoley EN. Congenital clubfoot: the results of treatment. J Bone Joint Surg Am. 1963;45:261-75. 4. Zionts LE, Sangiorgio SN, Ebramzadeh E, Morcuende JA. The current management of idiopathic clubfoot revisited: results of a survey of the POSNA membership. J Pediatr Orthop. 2012 Jul-Aug;32(5):515-20. 5. Zionts LE, Zhao G, Hitchcock K, Maewal J, Ebramzadeh E. Has the rate of extensive surgery to treat idiopathic clubfoot declined in the United States? J Bone Joint Surg Am. 2010 Apr;92(4):882-9. 6. Garcia NL, McMulkin ML, Tompkins BJ, Caskey PM, Mader SL, Baird GO. Gross motor development in babies with treated idiopathic clubfoot. Pediatr Phys Ther. 2011 Winter;23(4):347-52. 7. Sala DA, Chu A, Lehman WB, van Bosse HJ. Achievement of gross motor milestones in children with idiopathic clubfoot treated with the Ponseti method. J Pediatr Orthop. 2013 Jan;33(1):55-8. 8. Dim´eglio A, Bensahel H, Souchet P, Mazeau P, Bonnet F. Classification of clubfoot. J Pediatr Orthop B. 1995;4(2):129-36. 9. Flynn JM, Donohoe M, Mackenzie WG. An independent assessment of two clubfoot-classification systems. J Pediatr Orthop. 1998 May-Jun;18(3):323-7.
10. Iravani M, Chalabi J, Kim R, Ebramzadeh E, Zionts LE. Propofol sedation for infants with idiopathic clubfoot undergoing percutaneous tendoachilles tenotomy. J Pediatr Orthop. 2013 Jan;33(1):59-62. 11. Zionts LE, Frost N, Kim R, Ebramzadeh E, Sangiorgio SN. Treatment of idiopathic clubfoot: experience with the Mitchell-Ponseti brace. J Pediatr Orthop. 2012 Oct-Nov;32(7):706-13. 12. WHO Multicentre Growth Reference Study Group. WHO Motor Development Study: windows of achievement for six gross motor development milestones. Acta Paediatr Suppl. 2006 Apr;450:86-95. 13. Frankenberg W, Dodds J, Archer P, Bresnick B, Maschka P, Edelman N, Shapiro H. The DENVER II training manual. Denver: Denver Developmental Materials, Inc.; 1992. 14. Neligan G, Prudham D. Norms for four standard developmental milestones by sex, social class and place in family. Dev Med Child Neurol. 1969 Aug;11(4):413-22. 15. Davis BE, Moon RY, Sachs HC, Ottolini MC. Effects of sleep position on infant motor development. Pediatrics. 1998 Nov;102(5): 1135-40. 16. Capute AJ, Shapiro BK, Palmer FB, Ross A, Wachtel RC. Normal gross motor development: the influences of race, sex and socio-economic status. Dev Med Child Neurol. 1985 Oct;27(5):635-43. 17. Majnemer A, Rosenblatt B. Reliability of parental recall of developmental milestones. Pediatr Neurol. 1994 Jun;10(4):304-8.
