Dynamic US study in the evaluation of infants with vertical or oblique talus deformities

Pediatric Foot: Development, Variants, and Related Pathology

Pediatric foot development throughout childhood and adolescence can present a diagnostic dilemma for radiologists because imaging appearances may be confused with pathology. Understanding pediatric foot development and anatomical variants, such as accessory ossification centers, is essential to interpret musculoskeletal imaging in children correctly, particularly because many of these variants are incidental but others can be symptomatic. We first briefly review foot embryology. After describing common accessory ossification centers of the foot, we explain the different patterns of foot maturation with attention to irregular ossification and bone marrow development. Common pediatric foot variants and pathology are described, such as tarsal coalitions and fifth metatarsal base fractures. We also discuss pediatric foot alignment and various childhood foot alignment deformities.

Ankle and Foot Deformities in Children

Ankle and foot deformity is one of the most common musculoskeletal disorders in children and a leading cause of functional impairment and diminished quality of life when not treated. A spectrum of conditions may produce foot and ankle deformities, with congenital disorders the most frequent cause, followed by acquired conditions. Congenital disorders include congenital talipes equinovarus or congenital clubfoot, metatarsus adductus, skewfoot, congenital vertical talus, and tarsal coalition.Some of these deformities are frequent and easily diagnosed based on clinical features, but clinical overlap between pathologies can be challenging. Thus imaging plays a paramount role in evaluating these patients. Radiographs are the first imaging modality of choice, but they may not be sufficient in infants due to the lack of ossification of the tarsal bones. Ultrasonography allows not only a detailed visualization of the cartilaginous structures but also permits a dynamic study of the foot and ankle. Computed tomography may be necessary in certain conditions such as tarsal coalitions.

Multimodality imaging of the paediatric flatfoot

Flatfoot is commonly encountered in the paediatric population and describes a spectrum of clinical and radiological presentations which encompass both normally developing and pathological feet. Flatfoot can be categorised as flexible or rigid, a distinction which has important implications when considering the potential underlying aetiology and treatment options, and therefore imaging is an important component of the diagnostic workup. Weight-bearing plain radiographs are established initial investigations, although the significance of a number of the commonly derived quantitative parameters in children remains unclear. CT and MRI are important additional imaging modalities reserved for the investigation of symptomatic cases or those in which an underlying structural abnormality is suspected, rigid flatfoot commonly falling into one of these two categories. We review and illustrate the multimodality imaging of the paediatric flatfoot, with reference to both qualitative and quantitative radiographic assessment and cross-sectional imaging appearances.

Outcomes of a Minimally Invasive Approach for Congenital Vertical Talus With a Comparison Between the Idiopathic and Syndromic Feet

BACKGROUND

Congenital vertical talus (CVT) is a rare congenital foot disorder. Approximately half of the affected children have associated neuromuscular syndromes which may further complicate the treatment. The traditional treatment involved extensive soft tissue and bony reconstructions. The minimally invasive method (Dobbs method/reverse Ponseti) has changed the treatment of CVT. There is significant variation of the reported outcome of this method in the current literature. In this study we report the outcome of this minimally invasive technique for treatment of CVT and compare the results of treatment in syndromic and idiopathic patients.

METHODS

Idiopathic and syndromic patients treated from CVT with minimally invasive method from 2006 till 2016 were included in this retrospective study. We reviewed the patients' notes, radiographs and collected parents reported outcome questionnaire (Roye score) in addition to clinical examination to comprehensively report the treatment outcome.

RESULTS

A total of 21 patients 30 feet were included in this study. The average age of commencing treatment was 6 months (1 to 17 mo). The mean follow-up was 6.5 years (1 to 11 y). Correction of the deformities and abnormal angles were achieved in all feet. Five of the 17 syndromic feet had recurrence while no recurrence was reported in any if the 13 idiopathic feet. At the time of the index procedure no supplementary procedures were required. The average arc of motion for foot ankle dorsiflexion and plantar flexion was 30 degrees. Patients with idiopathic CVT had a mean the Roye score of 11 while syndromic patients had a mean score of 22.

CONCLUSION

The minimally invasive method is a valuable option for treatment of CVT. Idiopathic patients had no recurrence and better functional scores compared syndromic patients. There was no requirement for supplementary procedures such as tibialis anterior transfer or anterolateral release at the time of the initial surgery.

LEVEL OF EVIDENCE

Level IV-case series.

Can spinal deformity patients maintain proper arm positions while undergoing full-body X-ray?

Obtaining proper lateral full-body X-rays is paramount in accurately and consistently evaluating sagittal spinal alignment. This study explored the patient compliance rate of maintaining standardized arm position (fingers on the clavicles with shoulders in 45° of forward elevation while the patient is in a free-standing posture) during full-body X-rays at a single institution.

HYPOTHESIS

The compliance rate of arm positioning during full-body X-rays varies depending on operative status (preoperative vs postoperative), age, and diagnosis.

DESIGN

Retrospective cohort.

INTRODUCTION

Despite the importance of patients maintaining arms in the same position in preoperative and postoperative standing films, patients are known to have their arms in varying positions, confounding radiographic interpretation and making global sagittal and coronal spinal balance assessment variable and potentially less reliable. This study seeks to examine arm position compliance among adult and pediatric surgical spinal deformity patients undergoing total body X-rays over the course of 4 years (2015-2018).

METHODS

A retrospective radiographic review was performed on 382 spinal deformity patients from July 2015 to July 2018. The study's dependent variable of interest was standardized arm position (fingers on the clavicles with shoulders in 45° of forward elevation while the patient is in a free-standing posture) observed during full-body X-rays obtained for spinal deformity evaluation. Deviations and compliance to the standard protocol for full-body X-ray arm positioning was recorded and analyzed across various independent factors, including year of surgery, pre- and postoperative periods, type of spine surgery, and patient age. Chi-square and Cochran-Armitage analyses were performed to study categorical and trends, respectively.

RESULTS

The overall compliance rate for maintaining standardized arm position was 90% for all 370 patients (277 adult and 93 pediatric), in preoperative and postoperative setting. Adults were more likely to follow protocol than pediatric patients (92.9% vs. 82.4%, P value = 0.003). The postoperative setting observed a significantly lower overall compliance rate when compared to the preoperative period (67.8% vs. 87.0%, P value < 0.0001). Patients undergoing neuromuscular scoliosis (73.3%), vertebral column resection (VCR) (70%), and growing rod lengthening (GRL) (57.1%) had the lowest overall compliance rate in the preoperative setting. In the postoperative setting, patients with GRL, VCR, revision congenital scoliosis, congenital scoliosis, neuromuscular scoliosis, and pedicle subtraction osteotomy (PSO) surgeries were compliant less than or equal to 50% of the time. From 2015 to 2018, there was an overall statistically significant increase in compliance rate (61.1% to 90.6%). Over the study period, adult patients became significantly more compliant to protocol. This was not observed in the pediatric population.

CONCLUSION

This study documented the patient compliance rate of maintaining standardized arm position during full-body X-rays of spinal deformity patients. The overall compliance rate was 90.0% for all patients in the preoperative and postoperative setting. Risk factors for lower compliance rates included patients that were pediatric, postoperative, neuromuscular, and those who underwent a complex vertebral osteotomy or GRL. There was a trend showing improved compliance rate throughout the 4-year study period, which highlights the importance of having an ancillary staff who is comfortable with a consistent standard of care protocol. These results should help other centers optimize arm positioning in their patients undergoing full-body X-rays in the future.

What's New in Pediatric Flatfoot?

BACKGROUND

Children with flatfeet are frequently referred to pediatric orthopaedic clinics. Most of these patients are asymptomatic and require no treatment. Care must be taken to differentiate patients with flexible flatfeet from those with rigid deformity that may have underlying pathology and have need of treatment. Rigid flatfeet in infants may be attributable to a congenital vertical talus (CVT); whereas those in older children and adolescents may be due to an underlying tarsal coalition. We performed a review of the recent literature regarding evaluation and management of pediatric flatfeet to discuss new findings and suggest areas where further research is needed.

METHODS

We searched the PubMed database for all papers related to the treatment of pediatric flatfoot, tarsal coalition, and CVT published from January 1, 2011 to December 31, 2014, yielding 85 English language papers.

RESULTS

A total of 18 papers contributed new or interesting findings.

CONCLUSIONS

The pediatric flexible flatfoot (FFF) remains poorly defined, making the understanding, study, and treatment of the condition extremely difficult.Pediatric FFF is often unnecessarily treated. There is very little evidence for the efficacy of nonsurgical intervention to affect the shape of the foot or to influence potential long-term disability for children with FFF. The treatment of tarsal coalition remains challenging, but short-term and intermediate-term outcome studies are satisfactory, whereas long-term outcome studies are lacking. Management of the associated flatfoot deformity may be as important as management of the coalition itself. The management of CVT is still evolving; however, early results of less invasive treatment methods seem promising.

LEVEL OF EVIDENCE

Level 4-literature review.

Ultrasound evaluation of foot deformities in infants

Foot deformity in infants is the most common congenital musculoskeletal condition. A precise diagnosis can sometimes be impossible to establish clinically. Radiologic imaging plays a major role in the evaluation of musculoskeletal abnormalities. However conventional imaging techniques, such as plain radiographs of the foot, are of very little help in this age group because of the lack of ossification of the tarsal bones. US presents a significant advantage because it permits the visualization of cartilaginous structures. This leads to the detailed assessment of foot deformities in infants. Furthermore, US can also be used as a dynamic imaging modality. Different scanning views are beneficial to evaluate the complete anatomy of the foot; depending on the suspected clinical diagnosis, some planes are more informative to display the pathological features of a specific deformity. We describe the US findings of five of the most common foot deformities referred to our pediatric orthopedic clinic (clubfoot, simple metatarsus adductus, skewfoot, and oblique and vertical talus). For each deformity we propose a specific imaging protocol based on US to provide an accurate diagnosis. US is a complementary tool to the clinical examination for determining the diagnosis and the severity of the deformity and also for monitoring the efficacy of treatment. Radiologists investigating foot deformities in infants should consider using US for the detailed assessment of the foot in this age group.