Growth and development of tarsal and metatarsal bones in successfully treated congenital idiopathic clubfoot: early radiographic study

A four-year clinical and sonographic longitudinal follow-up of clubfeet treated according to Ponseti with normal references

Purpose

To follow children with a clubfoot by ultrasonography during the entire treatment period up to 4 years and compare with controls.

Method

Thirty clubfeet in 20 children treated using the Ponseti method and 29 controls were followed by repeated ultrasonography investigations from neonates to the age of 4 years. The previously established coronal medial and lateral, sagittal dorsal and posterior projections were used. Changes over time, correlations to the Diméglio score, and the course of treatment were studied.

Results

The medial malleolus-navicular distance was shorter, while the talar tangent-navicular distance and the talo-navicular angle were larger in clubfeet than in controls even after the initial correction. The healthy feet in unilateral cases did not differ significantly from the controls. The range of motion in the talo-navicular joint was approximately 20° less in clubfeet than in controls during the first four years of life. The medial malleolus-navicular distance (r = -0.58) and the talo-navicular angle (r = 0.66) at the first ultrasonography showed the highest correlation to the number of casts needed to correct the deformities.

Conclusion

Ultrasonography can be used to evaluate the initial degree of deformities in clubfeet and to follow the progress of the treatment and growth. Ultrasonography showed a clear difference between clubfeet and controls during the first four years of life. Although it was not possible to define specific limit values as benchmarks in the treatment, dynamic ultrasonography can provide valuable support in the decision-making process when complementary treatment may be needed.

Level of evidence

III.

Masking approaches to analyse plantar pressure data of new and confident walking infants

BACKGROUND

Due to its easy and straightforward use, regional analysis with the "standard" mask is the most common approach for quantifying plantar pressures in infancy. Such a mask, however, identifies foot regions based on typical foot proportions and pressure gradients. Alternatively, the use of a customised mask retaining infants' feet proportions has not been explored.

RESEARCH QUESTION

Does a customised mask scaled on infants' feet improve processing of pressure data collected during walking development compared with a standard mask?

METHODS

Thirteen infants walked across an EMED xl platform. Steps were grouped applying eight foot-regions standard and customised masks. To evaluate masks' performance, peak pressure (PP) and contact area (CA) were extracted from each region, and mask. Intra-individual coefficients of variation were then calculated for each variable, and compared between masks using a Mann-Whitney U test (p < 0.05). Unsuccessful masks application was reported, expressed as percentage of data loss.

RESULTS

For CA variation, significant differences were found in all the regions but the lateral toes in new (Z = -0.184, p = 0.8540) and confident walking (Z = -1.562, p = 0.118). For PP variation, a significant difference was found in confident walking within the lateral midfoot (Z = -2.598, p = 0.009). With the standard mask, 22-27 % of data was lost in new and confident walking respectively, compared to 1.6-0 % with the customised. As a result, the customised mask characterised the more variable steps, demonstrating higher variation compared to the standard mask.

SIGNIFICANCE

Identifying foot regions using a mask based on infants' feet proportions yielded an improved performance compared to the standard mask. With the customised mask, we retained almost all the steps and characterised the variability of the data, thereby providing an appropriate approach for infants' pressure data processing. Application of the customised mask could therefore be beneficial in future studies analysing highly variable data sets.

Longitudinal study of foot pressures during real-world walking as infants develop from new to confident walkers

Onset of walking in infants leads to regular cyclic loading of the plantar foot surface for the first time. This is a critical period for evolving motor skills and foot structure and function. Plantar pressure literature typically studies gait only once walking is established and under conditions that artificially constrain the walking direction and bouts compared to how infants move in the real-world. We therefore do not know how the foot is loaded when self-directed walking is first achieved and whether it changes as walking is practiced. Research question How do pressures on the plantar foot in real-world walking change from new to confident walking? Methods Fifty-seven infants participated in a two-site longitudinal study. Bespoke child-friendly spaces incorporated large pressure platforms and video. Data was collected at two milestones: new (403 days) and confident (481 days) walking. Steps were defined as walking straight or turning medially/laterally. Pressure variables were calculated for eight-foot regions and compared between milestones. Results Confident walking resulted in more steps (median: 18 v 35) and almost twice as many turning steps. During straight-line steps, confident walking increased peak pressures in the medial heel (median: 99.3 v 106.7kPa, p < .05) and lateral forefoot (median: 53.9 v 65.3kPa, p < .001) and reduced medial toe pressure (median: 98.1 v 80.0kPa, p < .05). Relative medial midfoot contact area reduced (median: 12.4 v 11.2%, p < .05) as absolute foot contact increased. A faster transition across stance and a reduced relative contact time in the forefoot were recorded in confident walking. Significance Pressures change rapidly as walking is initiated with significant differences in foot loading evident within an average 77 days. Importantly, these changes differ in straight and turning walking. Continued reliance on assessment of straight-line walking during early stages of ambulation likely fails to characterise 26% of steps experienced by infant feet.

Magnetic Resonance Imaging of Clubfoot Treated With the Ponseti Method: A Short-Term Outcome Study

OBJECTIVE

To quantitatively evaluate the effectiveness of the Ponseti method for the correction of clubfoot, we decided to use magnetic resonance imaging (MRI) to evaluate changes in the tarsal bone relationship.

METHODS

This is a retrospective study of fifteen children with clubfeet who were treated with the Ponseti method. MRI studies were obtained using a 3.0T Machine (GE Healthcare, United States). T1-weighted and T2-weighted images were acquired in the standard anatomic sagittal, transverse, and coronal planes. For the measurement, the best slice that clearly demonstrated the anatomy was chosen. Sagittal talocalcaneal angle, sagittal tibiocalcaneal angle, coronal tibiocalcaneal angle, transverse talar neck angle, transverse talonavicular angle, and transverse talocalcaneal angle were measured. The eighteen corrected clubfeet were compared with the twelve unilateral normal feet at clinical and radiological levels using a Pirani scoring system and MRI, respectively.

RESULTS

In total, 15 cases (twelve boys and three girls) with clubfeet were examined by using MRI. Twelve cases had unilateral and three had bilateral involvement (eleven left clubfeet and seven right clubfeet), giving a total of eighteen clubfeet when compared with twelve normal feet. The mean age of patients at examination was 47.7 months (8-96 months). The recovery of the corrected clubfoot in these patients met the goals of Ponseti treatment (functional, normal looking, pain-free, and plantigrade foot). Before Ponseti treatment, the mean Pirani score of clubfoot was 5.5 (5-6). During this follow-up, the Pirani score was 0.07 (0-0.05). The results of the MRI indicated that only the transverse talonavicular angle showed a significant difference between the treated clubfeet and the normal feet (p < 0.001). One case had dorsal talonavicular subluxation in the sagittal plane and had the lateral subluxation of the navicular in the transverse plane, which has never been reported in previous studies.

CONCLUSION

Although the appearance and function of clubfoot were recovered well after the Ponseti method, the results of MRI indicated that the Ponseti method successfully corrected the varus, cavus, and equinus deformities and incompletely corrected the adduction deformity regarding transverse talonavicular angle. At the same time, the Ponseti method may cause dorsal talonavicular subluxation in the sagittal plane and lateral subluxation of the navicular in the transverse plane on MRI.

A modification of the Ponseti method for clubfoot management: a prospective comparative study

PURPOSE

We aimed to compare our parent-based exercise programem's efficacy with the foot abduction brace (FAB) Ponseti manipulation as a retention programme.

METHODS

We conducted this prospective multicentre cohort study between August 2009 and November 2019. The included children were allocated into one of two groups according to the retention protocol. The Pirani and Laaveg-Ponseti scores were used to assess the feet clinically and functionally. Radiological assessment was performed using standing anteroposterior and lateral radiographs of the feet. We assessed the parents' satisfaction and adherence to the retention method. SPSS version 25 was used for the statistical analysis.

RESULTS

A total of 1265 feet in 973 children were included. Group A included 637 feet managed with FAB, while group B included 628 feet managed with our retention programme. All patients were followed up to the age of four years. At the final follow-up, Pirani scores in group A participants were excellent, good and poor in 515, 90, and 32 feet, respectivel, while in group B the scores were excellent, good and poor in 471, 110 and 44 feet, respectively. The mean total score of Laaveg-Ponseti was 87.81 (sd 19.82) in group A and 90.55 (sd 20.71) in group B (p = 0.02). Group B participants showed higher satisfaction with the treatment method (p = 0.011) and more adherence to the treatment (p = 0.013).

CONCLUSION

The deformity's recurrence related to the brace's non-compliance in the Ponseti method might be reduced by substituting the brace with our home-based daily stretching exercises.

LEVEL OF EVIDENCE

II.

Delayed ossification and abnormal development of tarsal bones in idiopathic clubfoot: should it affect bracing protocol when using the Ponseti method?

PURPOSE

To point out the need to take into account the dysplastic nature of tarsal bones when treating idiopathic clubfoot (CF).

METHODS

Review the published evidence on the developmental abnormalities of tarsal bones in idiopathic CF.

RESULTS

The literature review provides abundant proof of the existence of delayed appearance and slower development of ossification centres of tarsal bones in idiopathic clubfoot.

CONCLUSION

Gentle manipulations and casting are the cornerstone of the Ponseti method. The biological response of all foot elements is critical for a successful outcome. Delayed ossification and abnormal development of tarsal bones in idiopathic CF may affect the results. Development of a personalized tailored bracing protocol based on severity assessment and response to casting treatment will improve results and quality of care in CF management.

LEVEL OF EVIDENCE

V.

The significance of foot length at the initiation of the Ponseti method: a prospective study

OBJECTIVES

We sought to evaluate foot length (FL) and forefoot circumference (FC) and their impact on the severity of idiopathic clubfoot (CF) and results of treatment. We hypothesized that a smaller foot size at birth that represents a lesser than term newborn may affect the response of the CF to the treatment.

METHODS

We conducted a prospective study documenting FL and FC of all neonates presented with idiopathic CF. Additional demographic information was collected. Outcome measures were number of casts needed for correction, need for recasting, additional surgery and functional score.

RESULTS

In all, 52 children with 73 CF with a minimum mean follow-up of two years (2.0 to 5.6; sd 1.08) were evaluated. Mean gestational age was 38.63 weeks and mean birth weight (BW) was 3184 g. The mean FL at presentation was 74 mm (5.70 to 9.00), initial Pirani score was 5.5 (2.5 to 6.0) while number of casts was 6.9 (4.0 to 11.0). The FL was significantly correlated both to initial Pirani score (r = -0.35; p < 0.01) and number of casts (r = -0.33; p < 0.05). Positive correlation was found between the number of casts to Pirani score and number of additional procedures (r = 0.39; r = 0.36; p < 0.01, respectively). A foot size of up to 8 cm, needed 7.3 casts (4 to 7) compared with a FL of 8 cm or longer who needed 4.7 casts (4 to 6; t = 7.11; p < 0.001).

CONCLUSION

FL is a simple approach to identify preterm babies. It can be used as part of the initial evaluation of CF and help in predicting the course of treatment. We recommend adding FL to the existing classification.

LEVEL OF EVIDENCE

I - Prognostic study.

Foot size asymmetry following Ponseti treatment versus comprehensive surgical releases for unilateral clubfeet

Using age and height matched cohorts with unilateral idiopathic clubfeet (n=40 each), we retrospectively reviewed pedobarographic studies to determine the impact of treatment, Ponseti versus comprehensive surgical releases (CSR), on the foot length, width, and contact area. The foot pressures were determined by self-selected walking across a force plate. Ponseti treatment results in more symmetrical foot lengths, widths, and total contact areas with an improvement of 1.3 shoe sizes difference compared with treatment with CSR. This suggests that there is improved growth in the clubfoot in those treated with Ponseti management compared with those treated with CSR.

Alteration in hypoplasia of the hindfoot structures during early growth in clubfeet treated using the Ponseti method

PURPOSE

Previous reports have demonstrated diminished size of the hindfoot bones in patients with idiopathic clubfoot deformity. However, no study has quantified the percentage of hypoplasia as a function of early growth, during the brace phase of Ponseti treatment.

METHODS

We measured the dimensions of ossified structures on radiographs in patients with unilateral Ponseti-treated clubfeet to determine changes in the percentage of hypoplasia between two and four years of age.

RESULTS

The degree of hypoplasia varied among the osseous structures in Ponseti-treated clubfeet at age two years, with greater hypoplasia being observed in the talus (7.3%), followed by calcaneus (4.9%) and the cuboid (4.8%). Overall, the degree of hypoplasia diminished by four years, such that the degree of hypoplasia was greatest in the talus (4.2%) and the calcaneus (4.2%) followed by the cuboid (0.6%). At four years of age, the greatest degree of hypoplasia persisted in the talus and calcaneus.

CONCLUSIONS

Changes occurred in the size of the ossification of hindfoot bones between two and four years of age, and the observed changes in the percentage of hypoplasia varied among the different structures. At four years of age, the greatest percentage of hypoplasia was observed in the talus and calcaneus at values similar to those previously reported in skeletally mature patients. The results suggested that the relative difference in size of the feet may be expected to remain constant in a child with a unilateral clubfoot after this age.

RADIOGRAPHIC ABNORMALITIES OF THE TALUS IN PATIENTS WITH CLUBFOOT AFTER SURGICAL RELEASE USING THE MCKAY TECHNIQUE

Objective: To analyze morphological abnormalities of the talus in patients with clubfoot after surgical treatment using the McKay technique. Method: Lateral standing-position radiographs of the feet of 14 patients with unilateral clubfoot who underwent treatment by means of the doubleincision McKay technique were retrospectively analyzed. All the patients were operated by the same surgeon, with an average of 6.53 years between surgery and the radiograph. We compared the radiographic characteristics of the talus between the operated and the contralateral foot. We assessed the presence of deformity of the talar dome and head (sphericity evaluation); the talar length and height; the percentage and degree of navicular subluxation; abnormalities of the Gissane angle; and the trabecular bone pattern. Results: Abnormalities of the talar head occurred in 92.8% of the patients; of the talar dome in 92.8%; and of the trabecular pattern in 100%. The talar length ratio between the operated and the contralateral foot ranged from 0.61 to 0.88 (mean 0.79; SD = 0.09), while the height ratio ranged from 0.57 to 0.98 (mean 0.82; SD = 0.12). The Gissane angle was greater in all of the operated feet, and all of them also showed navicular subluxation, at a rate ranging from 6.43 to 59.75% (mean 26.34%; SD = 16.66%). Conclusion: Talar abnormalities occurred in 100% of the feet treated using the McKay technique. It was shown that establishing radiographic parameters to describe and quantify these deformities was feasible, through simple and easy-to-perform techniques.

Postnatal growth of the calcaneus does not simulate growth of the foot

BACKGROUND

In the absence of age and sex-specific normative data for postnatal growth of the calcaneus, it has been hypothesized that the growth of the calcaneus would simulate growth of the foot.

METHODS

A total of 860 normal lateral foot radiographs, 50 (25 female and 25 male) for each year of development from 1 to 18 years, and 10 radiographs from birth till 1 year, were measured for the length and height of the calcaneus, Bohler angle, the appearance, fusion and fragmentation of calcaneus apophysis, and the height and width of apophysis. Nonlinear curves were fit to a growth chart of the calcaneus, and the results were superimposed on the historical growth charts of the foot, stature, and long bones (femur, tibia). The ratio of calcaneus length to apophysis height was calculated.

RESULTS

Growth of the calcaneus does not simulate growth of the foot (which attains 50% of its mature dimension by the age of 1 y in girls and 1.5 y in boys), but simulates the growth of the long bones, which attain 50% of their mature length after the age of 3 years in girls and 4 years in boys. Bohler angle remains within normal limits across all ages. When the length of calcaneus is triple the height of its apophysis, 80% of calcaneus growth is complete.

CONCLUSIONS

We provide normative data for postnatal growth of the calcaneus. On the basis of these data, the assumption that growth disturbance in children affects the length of the calcaneus proportionately less than similar disturbances in the long bones, is false. Children <3 years have at least 50% of growth remaining. Bohler angle should be maintained at all ages.

CLINICAL RELEVANCE

This study of postnatal growth of the calcaneus provides age and sex-based normative data to predict growth pattern of calcaneus.