Clubfoot is one of the most common orthopedic conditions and affects males twice as often as femailes.1 Bilateral involvement occurs in approximately 50% of the cases.1 Nonoperative treatment is successful in reducing the need for surgery, but it is unclear how clubfoot affects a child's gross motor development. Some studies have investigated ankle and foot function under dynamic conditions such as overground gait.2,3 However, walking is only one of many aspects of gross motor development. A study in Japan evaluated the athletic ability of children with clubfeet, which included running and jumping activities,4 with no differences in unilateral versus bilateral involvement and need for surgery. However, only 30 children were evaluated, children were not categorized according to initial severity, and it is unclear whether Japanese children present similarly to children from the United States. A Swedish study found gross motor asymmetries5 with unilateral versus bilateral involvement. There were low to moderate correlations between gross motor skills and initial clubfoot severity, depending on the gross motor skill.5 However, none of these studies included a standardized, norm-referenced developmental assessment of gross motor abilities.
In a previous study of 81 children, 5 years of age, the Peabody Developmental Motor Scales, 2nd Edition (PDMS-2), test was compared to results from a gait analysis and parents' perceived outcomes.6 The group was divided children by Ponseti, French functional physical therapy, and surgical groups but not clubfoot severity or presence of bilateral versus unilateral involvement. The results were not provided by surgical or nonsurgical (Ponseti and French functional physical therapy groups) outcomes. It is unclear how severity related to gross motor abilities.5,6 Children with unilateral clubfeet can compensate on developmental tests with their nonclubfoot, which may result in higher scores than children with bilateral clubfeet. Previous research is unclear as to whether gross motor skills are affected by unilateral or bilateral involvement.4,5 The purposes of this study are to expand the sample size and evaluate the gross motor development of 5-year-olds using the PDMS-2 after nonoperative management of idiopathic clubfoot as infants, to evaluate PDMS-2 scores according to the initial clubfoot severity, unilateral versus bilateral involvement, and surgical versus nonsurgical outcomes.
One hundred twenty-eight children (85 males and 43 females) with idiopathic clubfeet were prospectively enrolled into a comprehensive clubfoot study and administered the PDMS-2 at the age of 5 years. Sixty-six children had bilateral clubfeet, and 62 children had unilateral clubfeet. Children were excluded if they had a diagnosis other than idiopathic clubfoot. A written informed consent was obtained from legal guardians. This study was approved by the Institutional Review Board at this institution.
Dimeglio Scale. The Dimeglio scale score is a valid, reliable grading system to classify the severity of the clubfoot deformity.7–9 The Dimeglio scale ranges from 0 to 20, with 0 indicating a typically developing foot. A rating of 5 or less is considered a benign clubfoot, 6 to 10 moderate, 11 to 15 severe, and 16 to 20 very severe.8,10 A score of 13 and below has been found to have a 90% chance for a nonsurgical outcome (exclusive of Achilles tenotomy) at 2 years of age.10 All children in our study had the severity of clubfoot, as defined by the Dimeglio score, graded at the initiation of treatment.
Peabody Developmental Motor Scales, 2nd Edition, Test. The PDMS-2 is a valid, reliable standardized examination of gross and fine motor skills in children.11 The Stationary, Locomotion, and Object Manipulation subtests were administered to obtain a composite Gross Motor Quotient (GMQ).
We reviewed the PDMS-2 scores for each tester to evaluate whether scores were similar across testers. After matching 3 variables—surgery or not, unilateral or bilateral involvement, and Dimeglio scale score—we found 12 participants to compare 5 testers. All PDMS-2 scores across testers were within a similar range with no significant differences.
All children were managed initially with nonoperative treatment as infants at the same institution. The nonoperative treatment methods consisted of either the Ponseti method or the French functional physical therapy method. These methods have been previously described in detail.12 In brief, the Ponseti method consists of weekly long-leg casts, a percutaneous Achilles tenotomy as needed, and a foot abduction orthosis until the age of 2 or 3 years for maintenance of correction.12,13 The French functional physical therapy method consists of daily exercises, taping, and ankle foot orthoses during correction and for maintenance of correction until the age of 2 or 3 years. A percutaneous Achilles tenotomy is also performed as needed.
The PDMS-2 was administered by a pediatric physical therapist at the 4.5- to 5.5-year follow-up visit. Five physical therapists were trained in the PDMS-2 and collected the data according to the testing manual.
Each patient's chart was reviewed for surgery. Since a percutaneous Achilles tenotomy is part of the nonoperative program of care, this procedure was not considered for surgery. Surgery other than an Achilles tenotomy (ie, posterior release, posterior medial release, anterior tibialis tendon transfer, plantar release, and/or lateral column shortening) was categorized as “surgery.”
Means and standard deviations were used to describe all the scored variables. A Mann-Whitney test was used to compare scored variables between groups. A χ2 test was used to compare categorical variables. A Spearman correlation was used to assess the associations between variables. An α level of <0.05 was used for statistical significance. For children with bilateral clubfeet, the foot with the more severe Dimeglio scale score was used for statistical analysis.
Children averaged 5.1 (0.3) years of age when the PDMS-2 was administered. There were no significant differences between the Ponseti method and the French functional physical therapy method for any of the Peabody domains (P = .564, Stationary score - .946, Object Manipulation score). Therefore, both non-operative treatment methods were combined into one non-operative treatment category. The average Dimeglio scale score was 13.0 ± 2.8. In children who required surgery, the average time from surgery until PDMS-2 testing was 24 ± 13 months. There was no association between Peabody scores and time from surgery (P = .334, Locomotion score = .899, Stationary score).
The average GMQ score for all children with clubfeet was 99, compared to age-matched normative scores. Children had “average” GMQ percentile scores in all subgroups studied, ranging from 44.5% to 48.4% (Table). Children with clubfeet also had “average” subtest standard scores overall (Stationary, Locomotion, and Object Manipulation) compared with age-matched normative scores (Table).
Developmental Motor Scales, 2nd Edition, Test Means (Standard Deviations)
||Dimeglio ≤13 n = 68
||Dimeglio >13 n = 55
||Unilateral n = 62
||Bilateral n = 66
||No Surgery n = 83
||Surgery n = 45
Abbreviations: GMQ, Gross Motor Quotient; Obj Manip, Object Manipulation; PDMS-2, Peabody Developmental Motor Scales, 2nd Edition.
Children with more severe clubfeet (Dimeglio scores >13) required surgery significantly more than children with less severe scores (P = .001). However, there were no significant differences in Peabody scores between the more severe and less severe groups for the subtest standard scores or GMQ scores (P = .094, Object Manipulation score = .699, Stationary score; Table). The more severe and less severe groups scored “average” on all subtest standard scores and GMQ scores.
Children with bilateral clubfeet were not significantly different on the PDMS-2 compared with children with unilateral clubfeet (P = .098, Object Manipulation score = 0.792, Locomotion score; Table). Children in both the bilateral and unilateral groups scored “average” on all subtest standard scores and GMQ scores. Children with more severe bilateral clubfeet required surgery significantly more than children with less severe bilateral clubfeet (P = .010). Children with more severe unilateral clubfoot also required surgery significantly more than children with less severe unilateral clubfoot (P = .035).
Forty-five children required surgery (35%), and 83 children did not require surgery. Children who required surgery did not score significantly different from children who had no surgery (P = .234, Locomotion score = 0.819, Stationary score; Table). Children in both the surgical and nonsurgical groups scored “average” on all subtest standard scores and GMQ scores. There was a trend for lower scores in children who required surgery, but this trend did not reach statistical significance (P = .234, Locomotion score = .819, Stationary score; Table). The GMQ percent scores for children who did not require surgery had a range of 13% to 90% of standardized scores, and the GMQ percent scores for children who required surgery had a range of 5% to 84% of standardized scores. When categorizing the GMQ scores in the surgical and nonsurgical groups, no significant differences were found between the categorical scores (P = .231, the Figure). Two of the 45 children who required surgery (4%) scored in the poor category. None of the 84 children not requiring surgery had poor scores (the Figure). No children in either surgical or nonsurgical groups scored “very superior,” “superior,” or “very poor.”
Clubfoot does not significantly impair gross motor development regardless of the initial severity, unilateral versus bilateral involvement, or surgery. Children scored “average” on Peabody standard subtest scores and GMQ scores. This information provides parents with prognostic information for expected gross motor abilities at school age. Physical therapists who perform the PDMS-2 on children with clubfeet can anticipate what to expect for this specific population.
Karol et al6 found that children with clubfeet did well developmentally at 5 years of age according to the PDMS-2. Our results with this larger cohort included some of the same children as Karol and colleagues'. However, our results differ from Karol and colleagues' in that they found differences in the Peabody scores between the French functional physical therapy and Ponseti groups, and we did not. Karol et al6 compared the French functional physical therapy, Ponseti, and surgery groups, whereas we just compared the French functional physical therapy and Ponseti groups regardless of surgical status. Although we likely included a more heterogeneous group of children compared with Karol and colleagues by including children who required surgery within the 2 nonoperative groups (French functional physical therapy and Ponseti), we did not find differences in Peabody scores between the surgical and nonsurgical groups. However, we noted that the 2 children who scored in the poor GMQ category had a history of requiring posteromedial releases, an extensive soft tissue release with capsulotomies for correction of resistant equinovarus deformity.
Lööf et al5 evaluated gross motor skills and asymmetries in children with clubfeet tested at 5 years of age. They found modest associations between gross motor skills and initial clubfoot severity. Single-leg hopping poorly correlated (−0.11) and heel walking moderately correlated (−0.45) with the initial Dimeglio score. They reported gross motor asymmetries in children with both bilateral and unilateral clubfeet. It is difficult to compare Lööf and colleagues' findings with our findings, since we did not evaluate the performance of the specific activity of one leg compared to another leg, but rather we compared overall scores between unilateral and bilateral children.
Kenmoku et al4 also reported satisfactory athletic ability (school physical fitness tests) for children with clubfeet tested at approximately 9 years of age. They subdivided children who required surgery versus those treated nonoperatively and with percutaneous tenotomies. Similar to our study, they found no differences between children treated nonoperatively and those with surgery. Kenmoku et al subdivided children by unilateral versus bilateral involvement, and, similar to our study, also reported no differences between groups. We did note clinically that most children preferred to use their less affected leg for balance if they had bilateral clubfeet or their unaffected foot if they had unilateral clubfoot. In particular, children preferred to stand on their unaffected foot and kick with their affected leg. Children preferred to lead with their affected leg for galloping, using the unaffected leg for strength and balance. Children with clubfeet had less excursion with standing on their tiptoes. Children with unilateral clubfeet preferred to use the unaffected leg for hopping, but they did not perform significantly better on the PDMS-2 than children with bilateral clubfeet. The unaffected foot in children with unilateral clubfoot has been found to demonstrate significant differences from peers developing typically according to pedobarographic measurements,3,14 gait,5 and ankle passive range of motion.5 Therefore, children with unilateral involvement may not have scored worse than children with bilateral involvement due to not having a “typical” unaffected foot as evidenced by compensatory changes in pressure patterns in response to weight bearing.
One major limitation of this study is that we do not have objective measures of the position of the children' feet when the PDMS-2 was performed. The Dimeglio scale score, including its parameters (equinus, varus, calcaneo-forefoot derotation, and forefoot adduction),9 may provide more detail into understanding whether their foot position influences their Peabody scores. Another limitation is that the therapists who performed the PDMS-2 did not establish interrater reliability, so we cannot be certain that our results were comparable across therapists. However, the PDMS-2 manual reports interscorer reliability from 97% to 99% of the reported scores.12
Future research is underway to evaluate these children at longer-term follow-up. More research is needed when participants are older (ie, 10 years of age) to see whether differences manifest after more growth, time, and involvement in sports. It is likely that the demands of higher levels of athletic participation in the teenage child will differentiate the clubfoot group from their normal peer group.
Gross motor development in most 5-year-old children with treated clubfeet is comparable to age-matched normative scores on the Peabody. Scores did not differ regardless of initial clubfoot severity, unilateral or bilateral involvement, and surgical or nonsurgical outcomes.
The authors wish to acknowledge the following physical therapists for performing the PDMS-2: Rosa Cooksey, Tony Hageman, Brenda House, Kim Kaipus, and Tamara Norton.
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