The reliability of measurements taken from radiographs in the assessment of paediatric flat foot deformity

Flatfoot Reconstruction for Painful Pediatric Idiopathic Flexible Flatfoot: Prospective Study Demonstrates Improved Alignment, Function, and Patient-reported Outcomes

BACKGROUND

This prospective study was undertaken to report outcomes following reconstructive surgery for patients with painful pediatric idiopathic flexible flatfoot.

METHODS

Twenty-five patients with pediatric idiopathic flexible flatfoot were evaluated pre- and post flatfoot reconstruction with lateral column lengthening (LCL). All patients had lengthening of the Achilles or gastrocnemius, while 13 patients had medial side soft tissue (MSST) procedures, 7 underwent medial cuneiform plantarflexion osteotomy (MCPO), and 5 had medializing calcaneal osteotomy. Measures of static foot alignment-both radiographic parameters and clinical arch height indices-were compared, as were measures of dynamic foot alignment and loading, including arch height flexibility and pedobarography. Preoperative and postoperative patient-reported outcome (PRO) scores were compared between those treated with or without MSST procedures.

RESULTS

The median subject age was 13.8 years (range: 10.3 to 16.5) at the time of surgery. All radiographic parameters improved with surgery ( P <0.001). The mean sitting arch height index showed a modest increase after surgery ( P =0.023). Arch height flexibility was similar after surgery. The mean center-of-pressure excursion index increased from 14.1% to 24.0% ( P <0.001), and the mean first metatarsal head (MH) peak pressure dropped ( P <0.001), while the mean fifth MH peak pressure increased ( P =0.018). The ratio of peak pressure in the fifth MH to peak pressure in the second MH increased ( P =0.010). The ratio of peak pressure in the first MH to peak pressure in the second MH decreased when an MCPO was not used ( P <0.002), but it remained stable when an MCPO was included. Mean scores in all PRO domains improved ( P <0.001). Patients treated without MSST procedures showed no difference in PROMIS Pain Interference scores compared to those without MSST procedures.

CONCLUSIONS

Flatfoot reconstruction surgery using an LCL with plantarflexor lengthening results in improved PROs. LCL changes but does not normalize the distribution of MH pressure loading. The addition of an MCPO can prevent a significant reduction in load-sharing by the first MH.

Reliability and correlation of weight-bearing cone beam CT and Foot Posture Index (FPI) for measurements of foot posture: a test-retest study

OBJECTIVE

To assess test-retest reliability and correlation of weight-bearing (WB) and non-weight-bearing (NWB) cone beam CT (CBCT) foot measurements and Foot Posture Index (FPI) MATERIALS AND METHODS: Twenty healthy participants (age 43.11±11.36, 15 males, 5 females) were CBCT-scanned in February 2019 on two separate days on one foot in both WB and NWB positions. Three radiology observers measured the navicular bone position. Plantar (ΔNAVplantar) and medial navicular displacements (ΔNAVmedial) were calculated as a measure of foot posture changes under loading. FPI was assessed by two rheumatologists on the same two days. FPI is a clinical measurement of foot posture with 3 rearfoot and 3 midfoot/forefoot scores. Test-retest reproducibility was determined for all measurements. CBCT was correlated to FPI total and subscores.

RESULTS

Intra- and interobserver reliabilities for navicular position and FPI were excellent (intraclass correlation coefficient (ICC) .875-.997). In particular, intraobserver (ICC .0.967-1.000) and interobserver reliabilities (ICC .946-.997) were found for CBCT navicular height and medial position. Interobserver reliability of ΔNAVplantar was excellent (ICC .926 (.812; .971); MDC 2.22), whereas the ΔNAVmedial was fair-good (ICC .452 (.385; .783); MDC 2.42 mm). Using all observers' measurements, we could calculate mean ΔNAVplantar (4.25±2.08 mm) and ΔNAVmedial (1.55±0.83 mm). We demonstrated a small day-day difference in ΔNAVplantar (0.64 ±1.13mm; p<.05), but not for ΔNAVmedial (0.04 ±1.13mm; p=n.s.). Correlation of WBCT (WB navicular height - ΔNAVmedial) with total clinical FPI scores and FPI subscores, respectively, showed high correlation (ρ: -.706; ρ: -.721).

CONCLUSION

CBCT and FPI are reliable measurements of foot posture, with a high correlation between the two measurements.

A Novel Deep Transfer Learning-Based Approach for Automated Pes Planus Diagnosis Using X-ray Image

Pes planus, colloquially known as flatfoot, is a deformity defined as the collapse, flattening or loss of the medial longitudinal arch of the foot. The first standard radiographic examination for diagnosing pes planus involves lateral and dorsoplantar weight-bearing radiographs. Recently, many artificial intelligence-based computer-aided diagnosis (CAD) systems and models have been developed for the detection of various diseases from radiological images. However, to the best of our knowledge, no model and system has been proposed in the literature for automated pes planus diagnosis using X-ray images. This study presents a novel deep learning-based model for automated pes planus diagnosis using X-ray images, a first in the literature. To perform this study, a new pes planus dataset consisting of weight-bearing X-ray images was collected and labeled by specialist radiologists. In the preprocessing stage, the number of X-ray images was augmented and then divided into 4 and 16 patches, respectively in a pyramidal fashion. Thus, a total of 21 images are obtained for each image, including 20 patches and one original image. These 21 images were then fed to the pre-trained MobileNetV2 and 21,000 features were extracted from the Logits layer. Among the extracted deep features, the most important 1312 features were selected using the proposed iterative ReliefF algorithm, and then classified with support vector machine (SVM). The proposed deep learning-based framework achieved 95.14% accuracy using 10-fold cross validation. The results demonstrate that our transfer learning-based model can be used as an auxiliary tool for diagnosing pes planus in clinical practice.

Really Asymptomatic? Health-Related Quality of Life and Objective Clinical Foot Characteristics among 5-10-Year-Old Children with a Flexible FlatFoot

The potential effects of asymptomatic flexible flatfoot (FF) on children's health-related quality of life (QoL) and objective clinical foot characteristics have been poorly investigated in the literature. Therefore, this study aimed to analyse these indicators, comparing the children with asymptomatic FF and a control group.

METHODS

In total, 351 children were enrolled in this cross-sectional study-160 children with asymptomatic FF and 191 controls (children with normal feet). The children and their parents completed the Paediatric Quality of Life Inventory (PedsQL^TM 4.0). The objective foot characteristics included clinical foot posture measures, footprints, general hyperlaxity, and X-ray measurements.

RESULTS

Children with asymptomatic FF had a significantly lower QoL (overall and all four dimensions). The parents' assessment of the QoL of their children with asymptomatic FF in most cases was lower compared to their children's self-reported QoL. Moreover, almost all clinical foot measures also had significantly worse profiles among asymptomatic FF cases compared to the controls. This was observed with the Foot Posture Index-6 (FPI-6), the navicular drop (ND) test, the Chippaux-Smirak Index (CSI), Staheli's Index (SI), the Beighton scale, and radiological angles (except the talo-first metatarsal angle).

CONCLUSION

The findings suggest that asymptomatic FF not always reflects a normal foot development. This condition is related to decreased health-related quality of life, so the 5-10-year-old children's and their parents' complaints should be considered more closely in identification, treatment, and monitoring plans.

Prospective Comparison of Subtalar Arthroereisis With Calcaneal Lengthening in the Management of Planovalgus Feet of Ambulatory Children With Spastic Cerebral Palsy?

BACKGROUND

Pes planovalgus (PPV) deformity is common among cerebral palsy (CP) patients. There is no true consensus about the best way of treating this common deformity, especially when surgical interference is required. Treatment options range from orthotics to complex surgical procedures. The purpose of this prospective study was to evaluate and compare the effectiveness of 2 different procedures in the correction of symptomatic flexible PPV in ambulatory CP patients.

METHODS

A total of 57 feet in 35 patients were divided into 2 groups: group 1, subtalar arthroereisis group, using the calcaneostop technique; group 2, lateral column lengthening group, using Evans osteotomy. Patients were assessed clinically by the clinical score proposed by Yoo et al and radiologically by measuring 7 weight-bearing angles, both preoperatively and 12 months postoperatively. Patients' (or parents') satisfaction and their tolerance to braces or shoes were assessed 12 months after surgery as secondary outcome parameters.

RESULTS

There was a statistically significant improvement in both primary and secondary outcome parameters after both procedures in comparison to the preoperative parameters. No statistically significant differences were observed between the 2 groups regarding the outcomes of both procedures except for the greater power of arthroereisis in the correction of hindfoot valgus, which was statistically significant both clinically and radiographically.

CONCLUSION

Both procedures are valid options for the surgical management of PPV in ambulatory children with spastic CP. The less-invasive nature and lower potential morbidity suggest that judicious use of arthroereisis is appropriate for some patients, especially in the context of single-event multilevel surgery.

LEVELS OF EVIDENCE

Level II: Prospective, comparative study.

Interobserver Reliability in the Radiological Evaluation of Flatfoot (Pes Planus) Deformity: A Cross-Sectional Study

This study was planned for analyzing the interobserver reliability on the diagnosis of flatfoot. This study aims to evaluate the interobserver reliability of the digital radiography of flatfoot patients. Eight parameters were used in digital x-rays within the as statistically in 2 groups. Study group includes 34 patients. Two groups were formed four medical specialists as 2 orthopedists and 2 radiologists. Two orthopedists made measurements on x-ray viewing as calcaneal pitch (CP) as CP floor, calcaneus-1 metatarsal angle, calcaneus-5 metatarsal angle; longitudinal arch angles (LAAs) as medial and lateral LAAs, Tomeno-Meary angle (TMA), anteroposterior and lateral CYMA line. The intraclass correlation coefficient (ICC) analysis was performed. Fleiss Kappa and Kappa was used to investigate the reliability of qualitative data between 2 observers. ICCs were in high levels for CP floor, calcaneus-1 metatarsal angle, calcaneus-5 metatarsal angle. ICCs of TMA was in high levels, also. ICCs of LAA-medial and LAA-lateral were not in high levels as other measurements. In the CYMA line (anteroposterior and lateral) Kappa was 0.140 for right feet in the quadruple group (p = .045; .458; and .314). Kappa was 0.197 for left feet in the quadruple group (p = .005; .146; .377). The ICCs was excellent for CP angles and TMA in all groups. LAAs as medial and lateral longitudinal arch angle had not high ICC's. CYMA line had significant p values in the quadruple group. But not in orthopedists and radiologists.

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.

Inter-observer and intra-observer reliability in the radiographic measurements of paediatric forefoot alignment

BACKGROUND

Foot bones in children have more rounded shapes in radiograms than adults. Thus, the goal of this work was assessing inter- and intra-observer reliability in paediatric forefoot angle measurements.

MATERIAL AND METHODS

Six forefoot angles in 34 AP standing paediatric foot radiographs were measured by 5 researchers. A classic statistical analysis with use of IBM SPSS Statistics 25 was performed and a new method with two-way analysis of variance was applied.

RESULTS

Results of statistical analysis revealed the properties of a subjective assessment related to specific angles. Kilmartin's angle, calcaneus-fifth metatarsal angle and first ray angle are the most reliable; metatarsus adductus angle should be used with great caution in pediatric population. Engel's angle is the most difficult for measuring and measurement error is the highest.

CONCLUSION

The power of paediatric forefoot measurements is various. Several angles are reliable, while Engle's angle is the most doubtful.

Comparison of multiple flatfoot indicators in 5-8-year-old children

Background

The foot posture is age dependent. The purpose of this study was to investigate the relationship between the 6-item version of the foot posture index (FPI) and other clinical, foot anthropometric, radiological measurements for the foot position in 5–8-year-old children.

Methods

A total of 301 participants with a mean age of 6.4  ±  1.14 years were enrolled in the study. Children were examined physically, clinically, and radiologically to measure the FPI and navicular drop (ND) test, resting calcaneal stance position (RCSP) angle, Chippaux–Smirak index (CSI), Staheli index (SI), calcaneal pitch (CP) angle, talocalcaneal angle (TCA), and the first lateral metatarsal angle. Tibial torsions, internal rotation of the hip as an indirect method of femoral anteversion, and Beighton scale were analyzed for factors associated with flatfoot prevalence.

Results

The study included children with normal and flexible flatfeet. Statistical analysis showed a significant FPI score correlation with other parameters (SI, CSI, RCSP, ND, CP, TMA, and TCA showed strong and moderate correlations, p < 0.001). Overall, the strongest associates are CSI (β = 0.34) and ND (β = 0.28). Other indicators have relatively small relationships with the FPI.

Conclusion

A positive correlation was observed between FPI-6 and ND test, CSI in 5–8-year-old children. All three prominent foot posture indicators (FPI-6, ND, and CSI) might be used as a primary or preferred tool in clinical practice.

Is there a correlation between static radiographs and dynamic foot function in pediatric foot deformities?

BACKGROUND

Idiopathic flexible flatfeet, congenital clubfeet and pes cavovarus are the most common foot deformities in children. Accurate assessment to quantify the severity of these deformities by clinical examination alone can be challenging. Radiographs are a valuable adjunct for accurate diagnosis and effective treatment. However, static radiographs during relaxed standing may not reflect the dynamic changes in the foot skeleton during functional activities such as walking. Therefore, the aim of this study is to predict dynamic foot movements during walking from planar standing radiographs to reveal the significance of the radiographic analysis for the assessment of foot function.

METHODS

Patients 8-17 years with flexible flatfeet (FFF, n=217) recurrent clubfeet (RCF n=38) and overcorrected clubfeet (OCCF, n=71) of non-neurogenic or syndromic origin and pes cavovarus due to peripheral neuropathy (PNP, n=48) were retrospectively included. Patients underwent gait analysis with the Oxford Foot Model and radiographic examination in anterior-posterior and lateral view during standing. Multilinear predictor analysis of selected gait parameters was performed based on radiographic measures.

RESULTS

The variance that was explained by radiography was greatest for the transverse plane forefoot abduction with 33% for OCCF, 50% for RCF and 59% for PNP. Flatfeet and foot kinematics in the other planes or between rearfoot and tibia showed little or no relation.

CONCLUSIONS

The static measures of foot deformities by radiography could explain only a small amount of variance in foot kinematics during walking, in particular for FFF. An explanation may be that the forces during weight bearing bear little resemblance to those during gait in terms of neither magnitude nor direction. These findings suggest that foot function cannot be accurately assessed solely from static radiographic observations of the foot, commonly undertaken in clinical practice.

Can positional MRI predict dynamic changes in the medial plantar arch? An exploratory pilot study

BACKGROUND

Positional MRI (pMRI) allows for three-dimensional visual assessment of navicular position. In this exploratory pilot study pMRI was validated against a stretch sensor device, which measures movement of the medial plantar arch. We hypothesized that a combined pMRI measure incorporating both vertical and medial displacement of the navicular bone induced by loading would be correlated with corresponding stretch sensor measurements.

METHODS

10 voluntary participants were included in the study. Both pMRI and subsequent stretch sensor measurements were performed in a) supine, b) standing and c) standing position with addition of 10 % body weight during static loading of the foot. Stretch sensor measurements were also performed during barefoot walking.

RESULTS

The total change in navicular position measured by pMRI was 10.3 mm (CI: 7.0 to 13.5 mm). No further displacement occurred when adding 10 % bodyweight (mean difference: 0.7 mm (CI: -0.7 to 2.0 mm), P = 0.29). The total navicular displacement correlated with stretch sensor measurement under static loading conditions (Spearman's rho = 0.66, P = 0.04) but not with measurements during walking (Spearman's rho = 0.58, P = 0.08).

CONCLUSIONS

Total navicular bone displacements determined by pMRI showed concurrent validity with stretch sensor measurements but only so under static loading conditions. Although assessment of total navicular displacement by combining concomitant vertical and medial navicular bone movements would appear advantageous compared to monoplanar measurement the combined measure did not seem to predict dynamic changes of the medial foot arch during walking, which are among several possible factors depending on different walking patterns.

Establishing normative foot posture index values for the paediatric population: a cross-sectional study

BACKGROUND

The Foot Posture Index (FPI) is an observational tool designed to measure the position of the foot. Its reliability is well established, and it provides normative reference values for the general population. However, this is not so for the paediatric population. The aim of this study is to determine FPI reference values in childhood, taking into account age and gender.

METHODS

This cross-sectional study included 1,762 school children (863 boys and 899 girls) aged 6-11 years, from Málaga, Granada and Plasencia (Spain). In every case, FPI measurements were obtained for both feet by two experienced podiatrists. A descriptive analysis was then conducted and the percentiles of the variables determined, with a significance level of P < 0.05.

RESULTS

The consolidated FPI results for the sample population produced mean values of 3.74 (SD 2.93) points for the right foot and 3.83 (SD 2.92) for the left. The 50th percentile was 4 points for both genders and for both feet, except for the right foot among the girls, which was slightly lower, at 3 points. The 85th percentile, which is considered to represent the boundary between the normal and the pronated foot among children, was 6 points, uniformly among the subjects.

CONCLUSIONS

As a normative FPI value for the paediatric population, we recommend the 50th percentile, i.e. 4 points, for children, of both genders, aged 6 years. This value progressively falls with age, to 3 FPI points for children aged 11 years. The 85th percentile for the pronated foot and the 4th percentile for the supinated foot can be considered the pathological boundary.

Navicular bone position determined by positional MRI: a reproducibility study

OBJECTIVE

To examine intraobserver, interobserver and between-day reproducibility of positional MRI for evaluation of navicular bone height (NVH) and medial navicular position (MNP).

MATERIALS AND METHODS

Positional MRI (pMRI) of the foot was performed on ten healthy participants (0.25 T G-scanner). Scanning was performed in supine and standing position, respectively. Two radiologists evaluated the images in a blinded manner. Reliability and agreement were assessed by calculation of intraclass correlation coefficient (ICC) and 95 % limits of agreement as a percentage of the mean (LOA%).

RESULTS

Intraobserver and interobserver reliability was "substantial" in both supine and standing position (ICC 0.86-0.98) and showed good agreement (LOA% 4.9-14.7 %). Between-day reliability of navicular height and medial navicular position in standing position remained substantial (ICC 0.85-0.92) with adequate agreement (LOA% 8.3-19.8 %). In supine position between-day reliability was "moderate" for NVH (ICC 0.72) and "slight" for MNP (ICC 0.39). Agreement remained adequate between-days for MNP in supine position (LOA% 17.7 %), but it was less than adequate for NVH in supine position (LOA% 24.2 %).

CONCLUSION

Navicular height and medial navicular position can be measured by pMRI in a very reproducible manner within and between observers. Increased measurement variation is observed between-days in supine position, which may be due to small positional differences or other unknown biomechanical factors.

Descriptive Quantitative Analysis of Rearfoot Alignment Radiographic Parameters

Although the radiographic parameters of the transverse talocalcaneal angle (tTCA), calcaneocuboid angle (CCA), talar head uncovering (THU), calcaneal inclination angle (CIA), talar declination angle (TDA), lateral talar-first metatarsal angle (lTFA), and lateral talocalcaneal angle (lTCA) form the basis of the preoperative evaluation and procedure selection for pes planovalgus deformity, the so-called normal values of these measurements are not well-established. The objectives of the present study were to retrospectively evaluate the descriptive statistics of these radiographic parameters (tTCA, CCA, THU, CIA, TDA, lTFA, and lTCA) in a large population, and, second, to determine an objective basis for defining "normal" versus "abnormal" measurements. As a secondary outcome, the relationship of these variables to the body mass index was assessed. Anteroposterior and lateral foot radiographs from 250 consecutive patients without a history of previous foot and ankle surgery and/or trauma were evaluated. The results revealed a mean measurement of 24.12°, 13.20°, 74.32%, 16.41°, 26.64°, 8.37°, and 43.41° for the tTCA, CCA, THU, CIA, TDA, lTFA, and lTCA, respectively. These were generally in line with the reported historical normal values. Descriptive statistical analysis demonstrated that the tTCA, THU, and TDA met the standards to be considered normally distributed but that the CCA, CIA, lTFA, and lTCA demonstrated data characteristics of both parametric and nonparametric distributions. Furthermore, only the CIA (R = -0.2428) and lTCA (R = -0.2449) demonstrated substantial correlation with the body mass index. No differentiations in deformity progression were observed when the radiographic parameters were plotted against each other to lead to a quantitative basis for defining "normal" versus "abnormal" measurements.

Reverse Ponseti-type treatment for children with congenital vertical talus: comparison between idiopathic and teratological patients

Children with congenital vertical talus (CVT) have been treated with extensive soft-tissue releases, with a high rate of complications. Recently, reverse Ponseti-type casting followed by percutaneous reduction and fixation has been described, with excellent results in separate cohorts of children with CVT, of either idiopathic or teratological aetiology. There are currently no studies that compare the outcome in these two types. We present a prospective cohort of 13 children (21 feet) with CVT of both idiopathic and teratological aetiology, in which this technique has been used. Clinical, radiological and parent-reported outcomes were obtained at a mean follow-up of 36 months (8 to 57). Six children (nine feet) had associated neuromuscular conditions or syndromes; the condition was idiopathic in seven children (12 feet). Initial correction was achieved in all children, with significant improvement in all radiological parameters. Recurrence was seen in ten feet. Modification of the technique to include limited capsulotomy at the initial operation may reduce the risk of recurrence. The reverse Ponseti-type technique is effective in the initial correction of CVT of both idiopathic and teratological aetiology. Recurrence is a problem in both these groups, with higher rates than first reported in the original paper. However, these rates are less than those reported after open surgical release.