MRI study of talonavicular alignment in club foot

Muscle volume evaluation using 3DCT for congenital clubfoot

Background

In congenital clubfoot, the lower leg is very thin and the calf muscles are hypoplasic. However, there are few studies reporting real muscle volume.

Purpose

The purpose of this study is to assay the muscle volume in congenital clubfoot using 3DCT and to quantify the degree of the hypoplasia.

Material and methods

From January 2015 to December 2016, nine consecutive patients, seven male and two female, with unilateral congenital clubfeet were recruited for CT scans. Axial transverse sectional CT scans were acquired from the delineation of the fibular head to the tibial plafond. From the data, we rendered the entire muscle in 3D for muscle volume assay, and further segmented the posterior musculature for comparison between the normal and affected sides.

Results

The whole muscle volume on the normal side was 291.23 cm³ (181.23–593.49) and that on the affected side was 225.08 cm³ (120.71–429.08), for an affected side to normal side ratio of 0.79 (0.72–0.9), which was significantly smaller (p < .01). Posterior muscle volume on the normal side was 175.81 cm³ (103.72–376.32) and that on the affected side was 106.52 cm³ (58.3–188.39). The ratio of posterior muscle to whole muscle on the normal side was 0.62 (0.46–0.75), and that on the affected side was 0.48 (0.4–0.55), such that the affected side was significantly smaller (p < .01)

Conclusion

This study contributes quantitative data supporting the longstanding observations that the posterior calf muscles are significantly smaller on the affected side compared to the normal side in congenital clubfoot, and further underscores the importance of the extending the excursion of these muscles.

Do the clinical scores (Pirani and Dimeglio scores) correlate with the radiological parameters in idiopathic club foot in infants? A cross-sectional study

This study was done to identify how well clinical scores and their sub-scores correlate with the radiographic parameters in idiopathic clubfoot. We studied 76 patients of idiopathic clubfoot who are from 5 months to 12 months of age. Deformity was assessed clinically with Pirani and Dimeglio scores and radiologically using eight parameters. Correlation between clinical and radiological scores was studied. All the eight radiological parameters were showing statistically significant correlation with clinical scores - both Pirani and Dimeglio scores. The mean total Pirani score at the time of X-ray was 2.31 with a SD of 1.58 (N = 118 minimum score = 0 and maximum score = 5.5), whereas the mean radiographic score was 3.67 with a SD of 2.1 (N = 118, minimum score = 0, maximum score = 8). The mean total Dimeglio score at the time of X-ray was 9.03 with a SD of 3.54 (N = 118, minimum score = 4 and maximum score = 15), whereas the mean total radiographic score was 3.67 with a SD of 2.1 (N = 118, minimum score = 0, maximum score = 8). Clinical scores correlate well with radiological parameters in infants with idiopathic clubfoot and hence the routine use of radiographs can be avoided in evaluation and follow-up thereby avoiding exposure to radiation.

Correlation of radiographic parameters with clinical correction in idiopathic congenital talipes equinovarus undergoing Ponseti treatment

PURPOSE

Idiopathic congenital talipes equinovarus is the most commonly encountered congenital deformity of the foot. Ponseti technique of manipulation is the treatment of choice. The Pirani classification is a reliable scoring system for clinical evaluation of clubfeet. The role of radiographic parameters in the evaluation and treatment of clubfeet is still controversial. The aim of this study was to evaluate the correlation of radiological parameters with clinical correction in patients with idiopathic clubfeet undergoing correction using Ponseti method.

METHODS

Between March 2018 and March 2019, 42 feet in 27 patients with idiopathic clubfeet were treated in our hospital. We used the Pirani scoring system for clinical evaluation. Anteroposterior and lateral views of the feet were taken before and after correction and at the last follow-up. The anteroposterior view was evaluated for the talocalcaneal angle and talo-first metatarsal angle, while the lateral view was only evaluated for the talocalcaneal angle.

RESULTS

Twelve were boys (44.4%), and 15 were girls (55.6%). The deformity was bilateral in 15 patients (55.6%) and unilateral in 12 patients (44.4%). The average age was three months. According to the Pirani score, the mean Pirani Total score was 4.4 before correction and reduced to 0.4 after correction. The mean talocalcaneal angle in anteroposterior and lateral views was 15.1° and 7.8° before correction, increased to 32.7° and 31.8° after correction, respectively. The mean talocalcaneal index increased from 23.2 before correction to 64.5 after correction. The mean talo-first metatarsal angle in anteroposterior view improved from 25.7° before correction to - 1.6° after correction. The relation between the differences in Pirani scores before and after correction and the differences in measured radiographic parameters before and after correction revealed a statistically significant correlation.

CONCLUSION

Radiographic parameters showed a statistically significant correlation with the clinical outcome. Thus, evaluation of clubfeet correction treated by Ponseti technique can rely mainly on clinical scores with limited utilization of radiological assessment.

Statistical shape modelling to analyse the talus in paediatric clubfoot

One fifth of idiopathic clubfoot deformities cannot be fully corrected by Serial Ponseti casting and deformity recurs in 20%-30% of cases. To avoid x-ray exposure, the joints with largely unossified bones are diagnosed with magnetic resonance images (MRI). Typically, geometric measurements are made in the MRI planes; however, this method is inaccurate compared to measurements on three-dimensional (3D) models of the joint. More accurate measurements using the 3D bone shapes may be better at identifying differences between groups; and therefore, improve diagnosis. The entire set of shape features from MRI can be analysed simultaneously through statistical shape modelling (SSM) which assesses bone morphology of clubfoot in a more sensitive way. A method for SSM of the talus is developed in this study and the shape of the normal talus is compared with the one in clubfeet with residual deformity through both geometric measurements and SSM. Significant differences between two groups were found by both methods; and therefore, might contribute to improve diagnosis of clubfoot.

Assessment of the talar deformity and alignment in congenital clubfoot using three-dimensional MRI after Ponseti method

BACKGROUND

Ponseti method have been widely accepted as the initial treatment of congenital idiopathic clubfoot because its excellent primary result. On the other hand, relapses after Ponseti method are not uncommon and the cause of relapses have not been fully elucidated. We investigated detailed morphology and alignment of tarsal bones in clubfoot after Ponseti method using three-dimensional MRI analysis.

METHODS

We performed MRI with 10 patients of unilateral clubfoot at three months after Achilles tenotomy. Based on the MRI volume data, we reconstructed three-dimensional bone surface model using the marching cubes method. We evaluated the volume of the talus and navicular bone, medial and planter deviation of the talar head and neck, medial deviation of the navicular bone, and internal rotation angle of the distal tibiofibular joint.

RESULTS

In clubfoot, the volume of talus and navicular bone were significantly smaller compared with the contralateral side. Deviation of the talar head and neck varied from medially to almost the same as that on the contralateral side. The degree of deformity of the talus and alignment of the navicular bone and distal tibiofibular joint showed correlations.

CONCLUSIONS

Patients with the medial deviated talar neck might have the alignment change of navicular bone and distal tibiofibular joint. Deformity of talar neck might to be compensated by talonavicular joint and distal tibiofibular joint through the manipulation of Ponseti method.

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.

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

Fifteen cases of unilateral clubfoot treated according to Ponseti's technique had the talocalcaneal angles on the anteroposterior and lateral views and the size of the talus, calcaneus, I-V metatarsus measured on radiographs of both feet that were taken at a mean age of 15.2 months (range 8-23). The measurements of talocalcaneal angles and size of the talus, calcaneus, and I, II, and III metatarsi were significantly smaller on the affected side, whereas the values for the IV and V metatarsi were similar on both sides. Clubfoot deformity involves all structures of the foot, but intrinsic compressive forces on the small hindfoot bones induce measurable reduction in their size and spatial orientation. This effect is seen early on the medial but not the lateral long tubular forefoot bones.

Ultrasound evaluation of clubfoot correction during Ponseti treatment: a preliminary report

BACKGROUND

The Ponseti method of manipulation is widely used in the treatment of clubfoot. Monitoring of correction is usually based on clinical judgment, and there is a need for an objective method of evaluation. The small bones of the newborn foot are essentially cartilaginous and can be visualized well on sonography as against radiographs.

METHODS

A prospective study was conducted on 32 clubfeet (26 subjects; age range, 12 days to 3 months) using ultrasound. Sonography was performed using the coronal medial projection at the start of treatment, when midfoot Pirani score was zero (foot fully abducted), and at the end of treatment. The medial malleolus to navicular distance and the talo-cuneiform angle were measured with foot position at rest and during the simulated Ponseti maneuver. The normal feet in unilateral cases served as controls.

RESULTS

With the Ponseti method of manipulation, there was a significant increase in the medial malleolus to navicular distance and improvement in the talo-cuneiform angle at the end of treatment, when compared with the pretreatment values (P < 0.001). All feet were clinically well corrected. However, 5 feet (15%) showed a "spurious correction," which was only detected on ultrasound. This was identified by the fact that the navicular was not fully reduced over the head of the talus, and there was a break in the naviculo-cuneiform joint. It was difficult to predict which feet were likely to develop a spurious correction, although the 5 feet in our study were stiffer, more severely deformed, and showed less correction on initial manipulation as compared with the feet that corrected well.

CONCLUSIONS

Clubfoot correction during serial manipulation can be monitored using sonography. An accurate realignment of the talo-navicular joint can be demonstrated, and presence of spurious correction can be detected early.

Achilles tendon length in children evaluated sonographically

The purpose of this study was to improve our knowledge of the behavior of the Achilles tendon as a basis for decision-making in Achilles lengthening or tenotomy, we sonographically measured the normal and club feet of 101 babies, mean age 4 months, in standard parameters: tibio-talo-calcaneal angle, length of Achilles tendon, distance from tibia to calcaneus, and distance from a line parallel to the posterior cortex of the tibia to the calcaneus. All measurements were age-matched from birth to 1 year in maximal plantar and dorsal flexion. In conclusion, we describe the normal values for the four parameters in plantar and dorsal flexion. These can serve as a basis for decision-making in clubfoot management.

3D reconstruction of the skeletal anatomy of the normal neonatal foot using 3D ultrasound

Currently imaging plays a limited role in the assessment of the neonate with a foot deformity. The aim of this study was to establish a technique for examining the neonatal foot with three-dimensional ultrasound (3D US). 3D US was attempted on the normal feet of 20 infants (9 male, 11 female) under 6 weeks old (range 35-41 days). The data sets were obtained whilst the infants were feeding or asleep to minimize movement artefact. A high-resolution optically tracked freehand 3D US system (Diasus, 16 MHz transducer) was used with Stradx software to acquire and analyse the data sets. Manual segmentation of the non-ossified tarsi from the data sets was performed. Five infants were too restless to be examined. 107 data sets were recorded from 22 feet of the remaining 15 infants. 21 of the data sets were discarded due to movement artefact. 86 were suitable for manual segmentation. Surface interpolation of the segmented data sets produced surface rendered reconstructions illustrating the complex 3D anatomy of the foot. This new technique may offer a method of examining the deformed foot, e.g. congenital talipes equinovarus.