Parent reported outcomes for idiopathic clubfoot children treated with the Ponseti technique: An analysis of 140 feet followed minimum 5 years

Abstract

Objective

The treated clubfoot children are often evaluated clinically during follow-up. However, patient reported outcomes (PROM) are seldom analysed for these children. We investigated 87 idiopathic clubfoot children (140 feet) treated by the Ponseti method and followed minimum 5 years to study their clinical outcomes and PROM.

Material and methods

This was a cross-sectional study, based on evaluating treated clubfoot children clinically (Pirani score) and PROM (Oxford Ankle and Foot Questionnaire – Parent Version) and comparing them with the age-matched healthy controls (n = 60). The questionnaire has four main domains related to the child's physical, school and play, emotional and footwear profile. The children having persistent deformity (residual/relapse) were specifically studied for their PROM scores.

Results

The mean child age at initial treatment was 2.3 months and the mean follow-up duration was 6.9 years. The PROM score of clubfoot children was statistically lower than the healthy controls (p < 0.001). Of the individual domains, the physical domain was the most affected. On calculating the Pirani scores, 10 out of 140 feet (7 %) had some form of persistent deformity. The children with persistent deformity had lower Oxford scores than healthy children or those with corrected feet. The physical domain followed by the emotional domain scored low when persistent deformity was present.

Conclusions

Most children (98 %) had a plantigrade foot following Ponseti treatment at follow-up. However, PROM score of the clubfoot children did not correspond to the clinical outcome. Persistent deformity, even minor, was a cause of parental concern and resulted in a low PROM score.

1. Introduction

Idiopathic clubfoot is a common congenital paediatric musculoskeletal problem.¹ The Ponseti method has undeniably superseded extensive surgical procedures in the last few decades, and its efficacy through minimally invasive techniques is beyond dispute.^2,3 Patient-reported outcome measures (PROM) have become a new modality of evaluation in addition to the clinical outcomes as the physician documented assessments may not always match parents' expectations.3, 4, 5 Alves et al. mentioned that due to their young ages, parents frequently speak on behalf of their young children, so it would be important to know their viewpoints to best align the clinical care.³ With this aim in mind, we analysed the parental satisfaction of idiopathic clubfoot children treated with the Ponseti method and followed for a minimum of 5 years. The study correlated the parental responses to the clinical evaluation of the Pirani score at the same follow-up.

2. Material and methods

This cross-sectional project (April–November 2023) was approved by the Institutional Ethics Committee and informed consent was obtained from the participants. The Institution runs a dedicated clubfoot clinic and a record of the clubfoot children treated with Ponseti method is preserved. We contacted clubfoot children (January 2013–December 2018) treated with the Ponseti method and called them for evaluation. The subjects for the study were the children with idiopathic clubfoot who were treated by the Ponseti method before the age of 2 years and followed up at least 5 years post-treatment. Their parents were also enrolled for the study. The study methodology involved clinical examination of the clubfoot child and administration of a validated questionnaire [Oxford foot and ankle questionnaire (OxAFQ), parent version, license to use obtained] to their parents. When both parents accompanied the child, the mother was administered the questionnaire. For comparisons, a control group consisting of parents of healthy children was also included.

The sample calculations were based on a previous study and assumed a mean difference of 8 for the OxAFQ domains between the clubfoot children and controls.³ To fulfil a statistical power of 0.8 and a type I error probability of 0.05, a minimum of 56 clubfoot children and 56 healthy controls were required. So, we took 60 age-matched healthy children as controls. Healthy controls comprised of children who visited the hospital with their parents (e.g. for immunization purpose, routine eye/dental check-up etc.).

Basic demographic data and complications such as persistent deformity (residual or relapse) were recorded for the children reporting for follow-up. The persistent deformity was defined as any Pirani score >0.⁶ Clinical evaluation was done with the help of the Pirani score as per the clinic protocol. The OxAFQ has a total of 15 items, 14 (the first 14 items) of which are used to calculate domain scores, the three domains being: Physical (6 items, 1–6) - School and Play (4 items, 7–10) - Emotional (4 items, 11–14). The response options to each item are on a 5-point scale rated from never (4), rarely (3), sometimes (2), very often (1) to always (0), where the number in brackets represents the value that should be applied by the scorer to each response. Domain scores are 10 calculated as the total of the scale item scores divided by the maximum for each domain (i.e., physical 24, school and play, emotional 16 each). The 15th item is related to foot wear profile rated on the above described 5-point scale. Domain scores can be transformed to a percentage scale (0–100) to aid interpretation. A higher score for a domain represented better functioning.⁷

2.1. Statistical analysis

Sample size calculations and statistical calculations related to the research were done on MedCalc® Statistical Software. The student t-test was used to detect differences in OxAFQ between responses from the clubfeet parents and controls. The parent satisfaction score was correlated to Pirani scoring (Pearson correlation coefficient). Children with persistent deformities were analysed as a subgroup. A p-value <0.05 was considered significant.

3. Results

Eighty-seven participants (n = 140 feet; bilateral = 53 children) whom we were able to contact and those reported for physical follow-up during the study duration were included for analysis. The mean child's age at the beginning of the Ponseti treatment was 2.3 ± 4.1 months and 7.1 ± 2.0 years at the time of follow-up. The mean follow-up duration was 6.9 ± 2.0 years. In the control group, there were 60 healthy children with a mean age of 7.4 ± 1.2 years.

The responses of parents (mother - 74; father - 13) of clubfoot and healthy children (mother - 40; father −20) for respective OxAFQ domains are presented in Table 1. The overall OxAFQ score for the clubfoot children was 262.8/304 (range, 64.58–304) while for the control group, it was 302.2/304 (range, 268.58–304) (p < 0.001). The highest scores in clubfoot children were reported for school and play items (89.5 SD 20), followed by emotional (88.3 SD 20.6). The parents were also comfortable with their children's shoe wear (score 3.8). However, overall parental satisfaction levels (262.8/302.2; 87.0 %) for clubfoot children were significantly lower than the healthy controls (p < 0.0001). The differences also extended for individual OxAFQ domains (i.e., physical, emotional, school and play) (p < 0.0001) and the footwear item (p = 0.0176).

Table 1.

OxAFQ questionnaire responses by parents of clubfoot and healthy children.

OxAFQ domain	Parents of clubfoot children (Mean values) (n = 87)	Parents of healthy children (Controls) (Mean values) (n = 60)	P- valuea
Physical (maximum score 100)	81.2 SD 25.4	98.7 SD 5.4	<0.001
School and play (maximum score 100)	89.5 SD 20	99.6 SD 3.2	<0.001
Emotional (maximum score 100)	88.3 SD 20.6	99.9 SD 0.8	<0.001
Footwear (maximum score 4)	3.8 SD 0.7	4 SD 0	0.017

^aStudent t-test.

Almost all (86/87; 98 %) children had plantigrade feet (none had equinus component >0.5) and painless ambulation. The mean Pirani score at follow-up was 0.05 (range, 0–2). Seven children (feet = 10) had persistent deformity. The most common persistent deformity was equinus (10/140 feet) followed by the curved lateral border (4/100 feet) and an unreduced talar head in 1 foot. All three deformities coexisted in 1 foot. Four feet that had curved lateral border also had residual equinus.

The scores (203.4/302.2; 67.3 %) lowered further in children with persistent deformity (n = 7) (Table 2). A significant difference emerged between scores for children with corrected clubfoot (n = 80) (267.9/302.2; 88.6 %) and those with persistent deformity (p < 0.0001). The domain most commonly altered following persistent deformity was the physical one. Even the children with corrected feet fared lower than healthy children in parental OxAFQ matching (p < 0.001). Overall, the parental OxAFQ scores had an inverse correlation with Pirani scoring (R = − 0.2377; p < 0.001).

Table 2.

OxAFQ scores of clubfoot children with persistent deformity (n = 7).

S. No.	Affected foot	Pirani Score	OxAFQ domains
			Physical	School and play	Emotional	Footwear
1	Right	0.5	100	56.25	100	4
	Left	0.5
2	Right	0.5	66.66	100	56.25	4
	Left	0.5
3	Right	1	16.66	87.5	68.75	4
	Left	1
4	Right	2	25	100	87.5	3
5	Left	0.5	25	12.5	43.75	1
6	Left	0.5	33.33	87.5	56.25	4
7	Left	1	95.83	81.25	100	4
Mean			51.8 SD 35.3	75 SD 31.3	73.2 SD 22.7	3.4 SD 1.1

4. Discussion

4.1. Principal findings

Parents might be more sensitive to their child's functioning and quality of life because they can observe their child directly and experience the impact the foot morphology.³ Therefore, for our study, we selectively analysed parental satisfaction (OxAFQ) for the idiopathic clubfoot children. The OxAFQ values reached satisfaction levels of almost 86 % although they stood lower than their healthy counterparts. The domain which clubfoot parents feared most was the physical domain (81.2/100, 81 %) and they were most comfortable reporting that their child was wearing normal footwear. An interesting finding which emerged from our research was persistent deformity being a cause of significant parental concern. Persistent deformity dragged the OxAFQ scores (203.4/302.2; 67 %) significantly lower when compared to those with corrected feet (267.9/302.2; 88.6 %) (p < 0.001). The OxAFQ scores demonstrated a statistically significant inverse correlation with the Pirani scoring. Our study thus demonstrated that the parents of clubfoot children remain cautious of their child's deformity several years post-treatment. This ‘not at par’ parental perspective deteriorated further if persistent foot deformity was present.

4.2. Comparisons with previous literature

Gelfer et al. listed in detail outcome measures used in various clubfoot studies including the patient-reported outcome measures (PROM) but did not analyse them further.⁸ One recent study used both parental and child OxAFQ to compare 53 treated clubfoot children out of 89 children with various foot disorders to the normal population (Table 3). The mean age of clubfoot children at the time of assessment was 10.3 ± 3.2 years. Clubfoot children and controls scored significantly differently (p < 0.0001) on all domains (i.e., physical, emotional, school and play) and the item footwear of the OxAFQ. Children and their parents significantly differed on the physical domain (p = 0.03) and the emotional domain of the OxAFQ, with parents’ ratings reflecting lower scores and poorer outcomes. Children and parents reported identical scores for the school, play, and footwear domains of OxAFQ in the above series.³

Table 3.

Literature review: Studies using parental OXFAQ for clubfoot children managed with Ponseti method.

Studies	Number of clubfoot children	Number of controls	Age at follow up (years)	OXFAQ-P Physical	OXFAQ-P School and play	OXFAQ-P Emotional	OXFAQ-P Foot wear	Satisfaction score of clubfoot children (%)
Mccahill et al.10	31	NA	8.3	64.1	80.0	83.1	NA	76
Tarakci et al.12	57	NA	7.26 ± 1.27	83.33± 17.24	72.14± 23.42	58.22 ± 16.33	32.17 ± 11.21	61
Alves et al.3	53	58	10.3 ± 3.2	0.53 ± 0.27a	0.77 ± 0.26a	0.69 ± 0.30a	2.14 ± 1.27a	66
Duffy et al.9	29	26	7.9	81.9 ± 20.4	95.7 ± 11.6	91.2 ± 13.7	67.2 ± 32.8	89
Current study	87	60	6.9 ± 1.9	81.2 ± 25.4	89.5 ± 20	88.3 ± 20.6	3.8 ± 0.7	87

Abbreviations: NA – Not available; OxAFQ – P (Parent Version of Oxford Ankle and Foot Questionnaire); Satisfaction score (observed scores/reference values).

^aScores calculated out of 1; foot wear score out of 4.

Duffy et al. compared children with normal feet (n = 29) and those with clubfoot treated either with the Ponseti method (n = 26) or an extensive surgical soft-tissue release (n = 23). The mean age was 7.9 years for clubfoot children and 6.5 years for controls. They found that while both children treated with the Ponseti method and extensive soft-tissue release had significantly lower parental OxAFQ scores than the control group in all domains, those treated with the Ponseti method had higher scores than the surgical group in the “emotional” and “school and play” domains.⁹

McCahill et al. compared 73 clubfeet children, of which 31 were treated conservatively and 42 were treated with surgical procedures. The Ponseti group had a mean age of 8.3 years (5–16 years). The surgery group had a mean age of 11.6 years (5–16 years). In the Ponseti group, parental OxAFQ physical 64.1 (range, 12.5 to 100), school and play 80 (range, 19 to 100), emotional 83.1 (range, 19 to 100) was recorded. In the surgical group, lower values of physical 58.2 (range,12.5 to 100), school and play 78.4 (range, 25 to 100), emotional 69.7 (range, 12.5 to 100) were present.¹⁰ In this study, the clubfoot children managed conservatively with the Ponseti method scored better than the surgical group. Within the domains, most affected was the physical domain.

The clubfoot deformity caused long-term concerns as obvious by the various above studies assessing the parental response. The satisfaction score of clubfoot children ranged between 61 and 89 % against healthy controls. In our study, the satisfaction levels were around 87 %. The physical domain emerged as the key domain of parental concern although other domains are also affected to some degree. The high correlation of persistent deformity with inferior PROM additionally established this relationship.

4.3. Clinical implications

Our study highlighted that the parents of clubfoot children were quite worried about the deformity their child was born with. The apprehension extended several years post-treatment and despite correction of the deformity. The presence of minimal persistent foot deformity lowered parental satisfaction. The clubfoot children should be kept in regular follow-up post Ponseti treatment. Any relapses, if any, should be aggressively treated.

4.4. Strength of the study

A validated score for clubfoot evaluation was used in the research.³ The primary strength was the study design with both robust numbers of subjects and controls. The study was based on the evaluation of a uniform cohort of clubfoot children treated with a single treatment protocol at the same clinic. The evaluation was performed (mean follow-up = 6.9 years) when all phases of clubfoot treatment (including the bracing period) were over and the feet had largely attained the final shape. Thus, parental and clinical outcomes at this time almost reflected the exact treatment outcome following the Ponseti method. We extended our analysis further to include subgroups of children with persistent deformity and corrected feet to pinpoint the parental concerns within them. The normal controls, without any foot problems, provided reference values of OxAFQ for our population and also for comparisons.

5. Limitations

Only the parental version of OxAFQ was used for the focused research since we intended to capture this aspect of PROM for the treated clubfoot children. As per our clinic protocol, the clubfoot child is routinely evaluated with Pirani scoring during follow-up and therefore the same was used as the clinical outcome instead of other foot parameters.^4,11

6. Conclusions

After undergoing Ponseti treatment, almost all children (98 %) showed a plantigrade foot during the long-term follow-up. The parental satisfaction as judged by the OxAFQ score reached 87 %. The OxAFQ score for clubfoot children was however significantly lower than their healthy counterparts. The presence of persistent deformity increased parental concerns and lowered the scores further. It is paramount to closely follow up with these children and provide timely intervention for persistent deformities, if any.

Funding

There is no funding source.

CRediT authorship contribution statement

Lokesh Sharma: Formal analysis, interpretation of data, Writing – original draft, approval of final version. Anil Agarwal: Conceptualization, Formal analysis, interpretation of data, Writing – original draft, approval of final version. Varun Garg: Formal analysis, interpretation of data, Writing – original draft, approval of final version. K.S. Ankitha: Formal analysis, interpretation of data, approval of final version. Kishmita Sachdeva: Formal analysis, approval of final version.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.