MRI study of talonavicular alignment in club foot

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.

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.

Clubfoot pathology in fetus and pathogenesis. A new pathogenetic theory based on pathology, imaging findings and biomechanics-a narrative review

Several studies have described the pathology of idiopathic congenital clubfoot (ICCF) in fetus. Numerous pathogenetic theories have been postulated on ICCF, but many of them lack any objective evidence. Pathologic studies in fetus together with MRI studies in patients with ICCF seem to favor the theory of a muscular imbalance of the foot activators during fetal growth as the main pathogenetic factor of ICCF. Our objectives were: (I) To support the theory of muscular imbalance as the primary pathogenetic factor of ICCF; (II) To clarify why atrophy and shortening affect the activator muscles of the foot unevenly, as reported by literature. A literature search based on MEDLINE and the COCHRANE database was performed to identify all published studies from 1929 to 2020 which report ICCF pathology in fetus, its etiopathogenesis, and imaging and biomechanical studies showing how the basic pathology may be addressed by Ponseti treatment. A manual search was also performed of the references cited in studies, reviews, and university libraries. Altered size, shape and articular relationships of the tarsal bones, and uneven atrophy and shortening of the leg muscles together with capsule and ligament abnormalities were the main pathologic findings reported in fetus with ICCF. Regarding ICCF pathogenesis, the main debate is between the advocators of a primitive blastemal defect of the tarsal bones leading to the skeletal abnormalities and those who hold that the latter are secondary to a deforming force generated by the soft tissues. Imaging studies have shown that the Ponseti method is able to address the skeletal abnormalities, the correction of which is maintained until adulthood, whereas leg muscle atrophy is not improved but tends to worsen with growth. Preliminary histochemical studies of the soleus-Achilles tendon junction have shown a decrease of the growth factors and the presence of myostatin, both down-regulators of muscle growth in patients with ICCF. The authors postulate that a defect of both the radial and the longitudinal growth unevenly affecting the leg muscles with a consequent imbalance of the foot activators might be the main pathogenetic factor of ICCF. Further studies are needed to confirm this theory.

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.

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.

Developing a Three-Dimensional (3D) Assessment Method for Clubfoot-A Study Protocol

Background: Congenital talipes equinovarus (CTEV) or clubfoot is a common pediatric congenital foot deformity that occurs 1 in 1,000 live births. Clubfoot is characterized by four types of foot deformities: hindfoot equinus; midfoot cavus; forefoot adductus; and hindfoot varus. A structured assessment method for clubfoot is essential for quantifying the initial severity of clubfoot deformity and recording the progress of clubfoot intervention.

Aim: This study aims to develop a three-dimensional (3D) assessment method to evaluate the initial severity of the clubfoot and monitor the structural changes of the clubfoot after each casting intervention. In addition, this study explores the relationship between the thermophysiological changes in the clubfoot at each stage of the casting intervention and in the normal foot.

Methods: In this study, a total of 10 clubfoot children who are <2 years old will be recruited. Also, the data of the unaffected feet of a total of 10 children with unilateral clubfoot will be obtained as a reference for normal feet. A Kinect 3D scanner will be used to collect the 3D images of the clubfoot and normal foot, and an Infrared thermography camera (IRT camera) will be used to collect the thermal images of the clubfoot. Three-dimensional scanning and IR imaging will be performed on the foot once a week before casting. In total, 6–8 scanning sessions will be performed for each child participant. The following parameters will be calculated as outcome measures to predict, monitor, and quantify the severity of the clubfoot: Angles cross section parameters, such as length, width, and the radial distance; distance between selected anatomical landmarks, and skin temperature of the clubfoot and normal foot. The skin temperature will be collected on selected areas (forefoot, mid foot, and hindfoot) to find out the relationship between the thermophysiological changes in the clubfoot at each stage of the casting treatment and in the normal foot.

Ethics: The study has been reviewed and approved on 17 August 2016 by the Sydney Children's Hospitals Network Human Research Ethics Committee (SCHN HREC), Sydney, Australia. The Human Research Ethics Committee (HREC) registration number for this study is: HREC/16/SCHN/163.

Prognostic Value of the Radiologic Appearance of the Navicular Ossification Center in Congenital Talipes Equinovarus

Congenital talipes equinovarus (CTEV), more commonly known as clubfoot, is a deformity of the foot that is not well understood. The tarsal navicular is at the center of the disease process and exhibits abnormal development and delayed ossification. However, its role in the pathologic process is not clear. The aim of the present study was to better understand the role of the tarsal navicular in CTEV by correlating the presence of the navicular ossification center and relapse of clubfoot deformity after surgical treatment. The medical records and radiographs of 34 patients (41 feet) with surgically treated CTEV were reviewed for the presence of the navicular ossification center and the lateral talocalcaneal angles. Of the 41 feet, 17 (41.46%) did not have the tarsal navicular ossification center present before surgery, and 24 (58.54%) did have the ossification center present. The talocalcaneal angles were similar between those with and without the navicular ossification center present. No significant difference was found in the incidence of relapse between the nonossified navicular group (17.6%) and the ossified navicular group (16.7%; p = .63). The presence of the navicular ossification center before surgery does not appear to have prognostic value for the relapse of CTEV after surgical intervention.

Sonography as an objective tool for monitoring serial corrections and detecting spurious corrections in clubfoot: a review

Ultrasonography is an emerging tool for monitoring clubfoot correction and for early diagnosis of spurious correction and of deformity recurrence. Sonography is widely available, inexpensive and has dynamic capability and can visualize tarsals in infants accurately.

Leg muscle atrophy in idiopathic congenital clubfoot: is it primitive or acquired?

PURPOSE

To investigate whether atrophy of the leg muscles present in congenital clubfoot (CCF) is primitive or secondary to treatment of the deformity.

METHODS

Magnetic resonance imaging (MRI) of both legs was taken in three cohorts of patients with unilateral congenital clubfoot (UCCF): eight untreated newborns (age range 10 days to 2 weeks); eight children who had been treated with the Ponseti method (age range 2-4 years); eight adults whose deformity had been corrected by manipulation and casting according to Ponseti, followed by a limited posterior release performed at age 2-3 months (age range 19-23 years). All of the treated patients wore a brace until 3 years of age. Muscles were measured on transverse MRI scans of both legs taken midway between the articular surface of the knee and the articular surface of the ankle, using a computer program (AutoCAD 2002 LT). The same program was used to measure leg muscles in the histologic cross sections of the legs of two fetuses with UCCF, spontaneously aborted at 13 and 19 weeks of gestation, respectively. Measurements of the whole cross section of the leg (total leg volume: TLV), of the muscular tissue (muscular tissue volume: MTV), and of the adipose tissue (adipose tissue volume: ATV) of the tibia, fibula, and of the other soft tissues (tendons, nerves, and vessels) were taken by using an interactive image analyzer (IAS 2000, Delta System, Milan, Italy).

RESULTS

Marked atrophy of the leg muscles on the clubfoot side was found in both fetuses and untreated newborns, with a percentage ratio of MTV between the normal and the affected leg of 1.3 and 1.5, respectively. Leg muscle atrophy increased with growth, and the percentage ratio of MTV between the normal and the affected leg was, respectively, 1.8 and 2 in treated children and adults. On the other hand, fatty tissue tended to increase relatively from birth to adulthood, but it could not compensate for the progressive muscular atrophy. As a result, the difference in TLV tended to increase from childhood to adulthood.

CONCLUSIONS

Our study shows that leg muscular atrophy is a primitive pathological component of CCF which is already present in the early stages of fetal CCF development and in newborns before starting treatment. Muscular atrophy increases with the patient's age, suggesting a mechanism of muscle growth impairment as a possible pathogenic factor of CCF.

A model for clubfoot based on micro-CT data

The pathological anatomy of idiopathic clubfoot has been investigated for more than 180 years using anatomy, computed tomography (CT), histology and microscopy. Seven idiopathic clubfeet and two normal feet of aborted fetuses were dissected in the present study, with special emphasis on the shape of the cartilage and bones. A three-dimensional (3D) micro-CT system, which generates a series of X-ray attenuation measurements, was used to produce computed reconstructed 3D data sets of each of the separated bones. Based on the micro-CT data scans a high-definition 3D colour printing system was used to make a four times enlarged clubfoot model, precisely presenting all the bony malformations. This model reflects the complexity of the anatomy of this disease and is designed to be used in the workshops of orthopaedic surgeons and physiotherapists, for training in new surgical and manipulation techniques.

Magnetic resonance imaging of the congenital clubfoot treated with the French functional (physical therapy) method

The purpose of this study was to assess magnetic resonance imaging (MRI) changes that occur in clubfeet after nonoperative treatment with the French functional method, specifically pertaining to the chondro-osseous anatomy and the joint relationships. The magnetic resonance images were obtained in 6 infants before treatment and 3 months later. The MRI protocol described previously for clubfeet which were treated by the Ponseti method (J Pediatr Orthop. 2001;21:719) was closely adhered to, except that no sedation was allowed by our institutional review board. The severity of the clubfoot deformities before treatment made assessment of the tibiotalar, talonavicular, and talocalcaneal joint relationships difficult in some feet. Despite this, improvements were noted after treatment in tibiotalar plantarflexion, the talonavicular relationship, the calcaneocuboid relationship, and the varus position of the calcaneus. The wedge shape of both the navicular and distal end of the calcaneus that occasionally was noted on the MRI before treatment improved after therapy. Although improved clinically, persistent equinus of the calcaneus on MRI was significant in 2 feet and was associated with slight dorsal displacement of the cuboid on the calcaneus (MRI evidence of rocker bottom). As noted with use of the Ponseti nonoperative treatment method, the chondro-osseous abnormalities seen on MRI studies in congenital clubfoot improve after treatment with the French functional (physical therapy) method, with the exception of equinus.

Cartilage anlagen adapt in response to static deformation

Connective tissue adaptation, including the development of cartilaginous anlagen into bones, is widely believed to be related to dynamic, intermittent load and stress histories. Static stresses, on the other hand, are generally believed deleterious in tissue adaptation. Using serial MRI in a natural human experiment (manipulation and corrective casting of infant clubfoot), we have observed casting produces two effects: (1) the well recognized change in relative positions of the hindfoot anlagen; (2) a newly recognized immediate shape change in the anlagen. These changes seemingly enhance the rate of growth of the anlagen and of the ossific nucleus. The shape change or deformation in the anlagen would occur as a result of alterations in the magnitudes and directions of loading from soft tissue attachments and muscle activity and would necessarily be associated with changes in the stress states within the anlagen and, when present, the ossific nuclei. Given the known role of load and stress history in tissue adaptation, we presume the reduced stress histories influence the enhanced growth rates. These observations contradict some current theories of tissue adaptation since static, rather than dynamic stresses play a crucial role in accelerating the growth and development of anlagen in the infant clubfoot.

Ultrasound assessment of early clubfoot treatment: a comparison of the Ponseti method and a modified Copenhagen method

The purpose of this study was to sonographically compare the early anatomical outcome of a group of clubfeet treated with the Ponseti method (group A, nine clubfeet) with a group treated with an adjustable plexidur splint, the Copenhagen method (group B, 19 feet). The clinical severity was assessed using the Diméglio-Bensahel classification. The need for complementary surgery was clinically assessed at the age of about 2 months. Ultrasound investigation was made in the neonatal period, after 2-3 months of non-surgical treatment and 1-2 months post-surgically. After 2 months of non-surgical treatment the correction obtained at the talo-navicular joint, expressed as the distance between the medial malleolus and the navicular (MM-N distance), was significantly greater in group A. After surgery, tenotomy of the Achilles tendon for all group A feet, and posterior or posteriomedial release for 13 feet in group B, the correction at the talo-navicular and calcaneo-cuboid joints was similar for the two groups. Anatomical correction of the displacement in these joints can be achieved without extensive interventional procedures. Ultrasound may be a valuable tool to assess the effects of different treatment protocols quantitatively.

Assessment of talus deformity by three-dimensional MRI in congenital clubfoot

PURPOSE

To evaluate the morphological deformity of talus in congenital clubfoot by three-dimensional MRI.

MATERIAL AND METHOD

Subjects were five patients (two male, three female, mean age 5 months) with unilateral congenital clubfoot. Magnetic resonance imaging was performed of both feet using 1.5 T magnet. Based on the resulting magnetic resonance imaging volume data, a three-dimensional surface bone model was reconstructed by the Marching Cubes method. The long axis of the reconstructed model was determined, and in relation to the standard planes including this axis, the degree of talar head and neck deviation, and the relative positioning of the talus and navicular in the talonavicular joint were compared between normal foot and clubfoot.

RESULT

The talar head and neck angle in relation to the talus exhibited significant medial deviation in the clubfoot, but the degree of plantar deviation of the talar head and neck did not show significance. The navicular was located more medially in clubfoot than in normal foot. The volume of the total talar and of the ossific nucleus for the clubfoot was smaller than that for the normal foot.

CONCLUSION

The assessment technique presented herein was shown to be useful in ascertaining the various pathological characteristics associated with clubfoot.