Surgical outcomes of cavovarus foot deformity in children with Charcot-Marie-Tooth disease

Two-stage corrective operation for the treatment of pes cavovarus in patients with spina bifida

BACKGROUND

Pes cavovarus has an estimated incidence of 8%-17% in patients with spina bifida (SB). The majority of the current literature on surgical treatment of cavovarus feet in children and adolescents includes a variety of diagnoses. There are currently no case series describing a treatment algorithm for deformity correction in this specific patient population. The authors of this study present the results of a retrospective case series performed to assess the radiographic outcomes of two-stage corrective surgery in patients with SB.

AIM

To assess the radiographic outcomes of a staged operation consisting of radical plantar release followed by osteotomy for pes cavovarus in patients with SB.

METHODS

Retrospective chart review was performed on patients with SB with a diagnosis of pes cavovarus at a freestanding children's hospital who underwent surgical correction of the deformity. Patients were excluded for lack of two-stage corrective operation, nonambulatory status, lack of at least six months follow-up, and age > 18 years at the time of surgery. This resulted in a cohort of 19 patients. Radiographic analysis was performed on 11 feet that had a complete series of preoperative and postoperative weightbearing X-rays. Preoperative and postoperative radiographic outcome measurements were compared using a two-sample t-test.

RESULTS

Significant changes between the preoperative and postoperative measurements were seen in Meary's angle, the anteroposterior talo-first metatarsal (AP TMT1) angle, and the talonavicular coverage. Mean values of Meary's angle were 17.9 ± 13.1 preoperatively and 4.7 ± 10.3 postoperatively (P = 0.016). Mean AP TMT1 angle was 20.6 ± 15.1 preoperatively and 9.3 ± 5.5 postoperatively (P = 0.011). Mean talonavicular coverage values were -10.3 ± 9.6 preoperatively and -3.8 ± 10.1 postoperatively (P = 0.025).

CONCLUSION

The two-stage corrective procedure demonstrated efficacy in correcting cavovarus deformity in patients with SB. Providers should strongly consider employing the staged surgical algorithm presented in this manuscript for management of these patients.

Foot surgery for adults with Charcot-Marie-Tooth disease

People with Charcot-Marie-Tooth (CMT) disease often undergo foot and ankle surgery, as foot deformities are common and cause a degree of functional limitations impairing quality of life. Surgical approaches are variable and there are no evidence-based guidelines. A multidisciplinary approach involving neurology, physical therapy and orthopaedic surgery is ideal to provide guidance on when to refer for surgical opinion and when to intervene. This review outlines the range of foot deformities associated with CMT, their clinical assessment, and their conservative and surgical and postoperative management.

A study concept of expeditious clinical enrollment for genetic modifier studies in Charcot-Marie-Tooth neuropathy 1A

BACKGROUND

Caused by duplications of the gene encoding peripheral myelin protein 22 (PMP22), Charcot-Marie-Tooth disease type 1A (CMT1A) is the most common hereditary neuropathy. Despite this shared genetic origin, there is considerable variability in clinical severity. It is hypothesized that genetic modifiers contribute to this heterogeneity, the identification of which may reveal novel therapeutic targets. In this study, we present a comprehensive analysis of clinical examination results from 1564 CMT1A patients sourced from a prospective natural history study conducted by the RDCRN-INC (Inherited Neuropathy Consortium). Our primary objective is to delineate extreme phenotype profiles (mild and severe) within this patient cohort, thereby enhancing our ability to detect genetic modifiers with large effects.

METHODS

We have conducted large-scale statistical analyses of the RDCRN-INC database to characterize CMT1A severity across multiple metrics.

RESULTS

We defined patients below the 10th (mild) and above the 90th (severe) percentiles of age-normalized disease severity based on the CMT Examination Score V2 and foot dorsiflexion strength (MRC scale). Based on extreme phenotype categories, we defined a statistically justified recruitment strategy, which we propose to use in future modifier studies.

INTERPRETATION

Leveraging whole genome sequencing with base pair resolution, a future genetic modifier evaluation will include single nucleotide association, gene burden tests, and structural variant analysis. The present work not only provides insight into the severity and course of CMT1A, but also elucidates the statistical foundation and practical considerations for a cost-efficient and straightforward patient enrollment strategy that we intend to conduct on additional patients recruited globally.

Short-term effects of foot surgery on walking-related pain, function, and satisfaction in patients with Charcot-Marie-Tooth disease: a prospective cohort study

Introduction

Patients with Charcot-Marie-Tooth disease (CMT) often suffer from walking-related pain (WRP), muscle weakness, foot deformities, and reduced ankle dorsiflexion (DF), which affects their ability to walk and daily activities. Functional surgery (FS) can restore foot deviations, affecting the loading ability during gait. We assessed the short-term effects of FS in patients with CMT on WRP, foot and ankle structure, and function, along with patients' perceived improvement.

Methods

This is a prospective cohort study on CMT patients who had undergone FS and rehabilitation. We analyzed the changes after 1 month, focusing on WRP, DF, the center of pressure progression (COPP) during walking, and measures of walking ability. The non-parametric Wilcoxon test was used.

Results

Ten patients were included. One month after FS, WRP reduced from 5.5 (IQR = 3.5) to 2 (IQR = 3.5), p = 0.063, with an effect size of 0.615. The highest decrease was found in patients with very high pre-surgical pain levels. DF almost reached 10° for both active and passive movements (p < 0.05), and COPP improved from 44 to 60% (p = 0.009) of foot length. Gait speed, lower limb functioning, and balance did not change. More than half of the sample felt improved or much improved after FS.

Conclusion

FS can be effective in reducing WRP and restoring foot posture in CMT patients in the short-term, which allows them to wear shoes, and leads to a perceived improvement and satisfaction. Lack of improvement in functional skills may be due to muscle weakness typical of CMT. Studies with longer follow-ups may confirm these hypotheses.

Clinical trials in Charcot-Marie-Tooth disorders: a retrospective and preclinical assessment

Objective

This study aimed to evaluate the progression of clinical and preclinical trials in Charcot-Marie-Tooth (CMT) disorders.

Background

CMT has historically been managed symptomatically and with genetic counseling. The evolution of molecular and pathologic understanding holds a therapeutic promise in gene-targeted therapies.

Methods

ClinicalTrials.gov from December 1999 to June 2022 was data extracted for CMT with preclinical animal gene therapy trials also reviewed by PubMed search.

Results

The number of active trials was 1 in 1999 and 286 in 2022. Academic settings accounted for 91% and pharmaceutical companies 9%. Of the pharmaceutical and academic trials, 38% and 28%, respectively, were controlled, randomized, and double-blinded. Thirty-two countries participated: the United States accounted for 26% (75/286). In total, 86% of the trials were classified as therapeutic: 50% procedural (21% wrist/elbow surgery; 22% shock wave and hydrodissection therapy), 23% investigational drugs, 15% devices, and 11% physical therapy. Sixty-seven therapeutic trials (49%) were designated phases 1-2 and 51% phases 3-4. The remaining 14% represent non-therapeutic trials: diagnostic testing (3%), functional outcomes (4%), natural history (4%), and standard of care (3%). One-hundred and three (36%) resulted in publications. Phase I human pharmaceutical trials are focusing on the safety of small molecule therapies (n = 8) and AAV and non-viral gene therapy (n = 3). Preclinical animal gene therapy studies include 11 different CMT forms including viral, CRISPR-Cas9, and nanoparticle delivery.

Conclusion

Current CMT trials are exploring procedural and molecular therapeutic options with substantial participation of the pharmaceutical industry worldwide. Emerging drug therapies directed at molecular pathogenesis are being advanced in human clinical trials; however, the majority remain within animal investigations.

Quantitative assessment of plantar pressure patterns in relation to foot deformities in people with hereditary motor and sensory neuropathies

BACKGROUND

Hereditary motor and sensory neuropathies (HMSN), also known as Charcot-Marie-Tooth disease, are characterized by affected peripheral nerves. This often results in foot deformities that can be classified into four categories: (1) plantar flexed first metatarsal, neutral hindfoot, (2) plantar flexed first metatarsal, correctable hindfoot varus, (3) plantar flexed first metatarsal, uncorrectable hindfoot varus, and (4) hindfoot valgus. To improve management and for the evaluation of surgical interventions, a quantitative evaluation of foot function is required. The first aim of this study was to provide insight into plantar pressure of people with HMSN in relation to foot deformities. The second aim was to propose a quantitative outcome measure for the evaluation of surgical interventions based on plantar pressure.

METHODS

In this historic cohort study, plantar pressure measurements of 52 people with HMSN and 586 healthy controls were evaluated. In addition to the evaluation of complete plantar pressure patterns, root mean square deviations (RMSD) of plantar pressure patterns from the mean plantar pressure pattern of healthy controls were calculated as a measure of abnormality. Furthermore, center of pressure trajectories were calculated to investigate temporal characteristics. Additionally, plantar pressure ratios of the lateral foot, toes, first metatarsal head, second/third metatarsal heads, fifth metatarsal head, and midfoot were calculated to measure overloading of foot areas.

RESULTS

Larger RMSD values were found for all foot deformity categories compared to healthy controls (p < 0.001). Evaluation of the complete plantar pressure patterns revealed differences in plantar pressure between people with HMSN and healthy controls underneath the rearfoot, lateral foot, and second/third metatarsal heads. Center of pressure trajectories differed between people with HMSN and healthy controls in the medio-lateral and anterior-posterior direction. The plantar pressure ratios, and especially the fifth metatarsal head pressure ratio, differed between healthy controls and people with HMSN (p < 0.05) and between the four foot deformity categories (p < 0.05).

CONCLUSIONS

Spatially and temporally distinct plantar pressure patterns were found for the four foot deformity categories in people with HMSN. We suggest to consider the RMSD in combination with the fifth metatarsal head pressure ratio as outcome measures for the evaluation of surgical interventions in people with HMSN.

Foot Assessment Clinical Scales in Charcot-Marie-Tooth Patients: A Scoping Review

Introduction

Charcot-Marie-Tooth disease (CMT) is a slow and progressive peripheral motor sensory neuropathy frequently associated with the cavo-varus foot deformity. We conducted a scoping review on the clinical scales used to assess foot deviations in CMT patients and analyzed their metric properties.

Evidence Acquisition

A first search was conducted to retrieve all scales used to assess foot characteristics in CMT patients from the Medline, Web of Science, Google Scholar, Cochrane, and PEDro databases. A second search was conducted to include all studies that evaluated the metric properties of such identified scales from the same databases. We followed the methodologic guidelines specific for scoping reviews and used the PICO framework to set the eligibility criteria. Two independent investigators screened all papers.

Evidence Synthesis

The first search found 724 papers. Of these, 41 were included, using six different scales: “Foot Posture Index” (FPI), “Foot Function Index”, “Maryland Foot Score”, “American Orthopedic Foot & Ankle Society's Hindfoot Evaluation Scale”, “Foot Health Status Questionnaire”, Wicart-Seringe grade. The second search produced 259 papers. Of these, 49 regarding the metric properties of these scales were included. We presented and analyzed the properties of all identified scales in terms of developmental history, clinical characteristics (domains, items, scores), metric characteristics (uni-dimensionality, inter- and intra-rater reliability, concurrent validity, responsiveness), and operational characteristics (normative values, manual availability, learning time and assessors' characteristics).

Conclusions

Our results suggested the adoption of the six-item version of the FPI scale (FPI-6) for foot assessment in the CMT population, with scoring provided by Rasch Analysis. This scale has demonstrated high applicability in different cohorts after a short training period for clinicians, along with good psychometric properties. FPI-6 can help health professionals to assess foot deformity in CMT patients over the years.

Falls and Associated Factors among Adolescents and Young Adults with Arthrogryposis Multiplex Congenita

Background:

Falls research among individuals with arthrogryposis multiplex congenita (AMC), a group of congenital conditions characterized by joint contractures in two or more body regions, is sparse. The primary objectives of this study were to estimate the prevalence of single, multiple, and injurious falls among adolescents and adults with AMC and identify factors associated with multiple and injurious falls.

Methods:

Individuals, aged 10–50 years, with a diagnosis of AMC completed questionnaires obtaining demographic and AMC-specific information, falls history (e.g., number, injurious/non-injurious), markers of bone health, orthopedic surgical history, and mobility aid use, as well as the Gillette Functional Assessment Questionnaire and the Saltin-Grimby Physical Activity Level Scale. Falls were defined as “any body part above the ankle coming to rest on the ground, floor, or a lower level”. Falling was defined as ≥ 1 fall, while multiple falls were defined as ≥ 2 falls in the past year.

Differences in falling, multiple falls, and injurious falls rates between adolescents (10–17 years) and adults (aged 18–50 years) were evaluated. Using univariate binary logistic regression models, associations between participant characteristics and multiple falls, as well as injurious falls, were evaluated, while considering age as a covariate (p ≤ 0.050); odds ratios (ORs) and 95% confidence intervals (CIs) were calculated.

Results:

Adolescents (N = 28; median age = 14 years) and adults (N = 40; median age = 32 years) with AMC had similar falling, i.e., 89.3% versus 70.0%, and injurious fall rates, i.e., 32.1% versus 27.5%, respectively (p > 0.050).

Adolescents with AMC, however, were more likely to report multiple falls in the past year, i.e., 89.3%, when compared to adults with AMC, i.e., 57.5% (p = 0.005). Beyond age, multiple falls were associated with a greater number of lower-limb surgeries [p = 0.036, OR (95%CI): 1.18 (1.01–1.39)], ability to transfer floor-to-stand with support [p = 0.002, OR (95%CI): 8.98 (2.30–35.06)], and increased mobility per the Gillette Functional Assessment Questionnaire [p = 0.004, OR (95%CI): 1.48 (1.13–1.92)]. Factors associated with a reduced odds of multiple falls were spinal involvement [p = 0.025, OR (95%CI): 0.23 (0.07–0.84)], history of spinal surgery [p = 0.018, OR (95%CI: 0.18 (0.04–0.74)], greater upper extremity involvement [OR (95%CI): 0.65 (0.44–0.95)], home assistive device use [p = 0.010, OR (95%CI): 0.15 (0.03–0.63)], and community wheelchair use [p = 0.006, OR (95%CI): 0.16 (0.04–0.59)]. None of the explored characteristics were associated with injurious falls in the past year (p > 0.050).

Conclusion:

Falls are exceedingly common among adolescents and adults with AMC; potential risk and protective factors for multiple falls are identified for future prospective falls research.

How to manage pes cavus in children and adolescents?

Pes cavus in its different forms is not a pathological entity, but rather the manifestation of multiple diseases.

Cavovarus, a form of cavus foot, should never be considered a physiological deformity. A neurological condition should always be excluded.

The evolution of pes cavovarus is unpredictable because of the large number of conditions involved in its aetiology, as well as their variable degree of expression. About 66% of cavovarus feet are the result of subtle neurological diseases, which only become evident later in life.

Although surgery may not change quality of life, recent studies suggest that it may improve foot posture and reduce walking instability.

The aim of treatment is to preserve a painless, plantigrade, mobile foot. Management consists of correcting bone deformity while preserving movement, and the wise use of rebalancing techniques. Arthrodesis should only be a salvage procedure.

Cite this article: EFORT Open Rev 2021;6:510-517. DOI: 10.1302/2058-5241.6.210021

Dynamic plantar pressure patterns in children and adolescents with Charcot-Marie-Tooth disease

BACKGROUND

The dynamic plantar pressure patterns of children and adolescents with Charcot-Marie-Tooth (CMT) disease and its relationship to musculoskeletal alterations may help to understand the natural history of the disease and improve therapeutic interventions.

RESEARCH QUESTION

The study compared dynamic plantar pressure patterns in children and adolescents with and without CMT. It also tested the associations between isometric muscle strength (IMS), passive range of motion (ROM), foot posture and dynamic plantar pressure patterns in CMT.

METHODS

This cross-sectional study compared children and adolescents (aged 8-18 years) with CMT (n = 40) with a typical group (n = 40). The plantar pressure distribution during gait was recorded, and the contact area (CA), peak pressure (PP), contact time (CT) and pressure-time integral (PTI) in five foot regions (rearfoot, midfoot lateral, midfoot medial, lateral forefoot and medial forefoot) were analysed. The IMS of the dorsiflexors and plantar flexors, passive ROM, and foot posture were also recorded.

RESULTS

PP (medial midfoot and medial forefoot) and PTI (rearfoot, lateral midfoot and medial forefoot) were higher in children with CMT compared with the typical group. The adolescents with CMT presented a less CA (whole foot) and a higher CT (medial midfoot) when compared with typical group. For CMT, in the medial midfoot, plantar flexor IMS associated with PP (β=-11.54, p = 0.01) and PTI (β=-3.38, p = 0.04); supinated foot posture associated with PP (β = 33.89, p = 0.03) and PTI (β = 12.01, p = 0.03).

SIGNIFICANCE

Children with CMT showed clear changes in most of the dynamic plantar pressure variables, while adolescents with CMT showed changes mostly in CA and CT. This information together with the associations established between supinated foot, dorsiflexion ROM and plantar flexions IMS can be useful for guiding rehabilitation professionals in their therapies.

Management of flexible cavovarus foot in patients with Charcot-Marie-Tooth disease: midterm results

INTRODUCTION

Charcot-Marie-Tooth disease (CMT) is a hereditary motor sensory neuropathy that frequently results in a cavovarus foot in the adult. Surgical treatment allows correction of the deformity while preserving an adequate range of motion.

OBJECTIVE

The objective of this study was to assess the result of posterior tibial tendon transfer, first metatarsal ascent osteotomy, and calcaneal valgus osteotomy in the treatment of cavovarus foot secondary to CMT.

MATERIAL AND METHODS

Retrospective cohort of CMT patients who received surgical treatment of their cavovarus foot. Collected data included demographics, CMT genetic variant, neurologic involvement, surgical technique, range of motion, functionality, radiology, and postoperative satisfaction.

RESULTS

16 patients met the inclusion criteria, mostly women (62.5%) with the CMT1A variant (62.5%), and a mean age of 39.5 years. 13 patients required additional surgical techniques: lengthening of the Achilles tendon, interphalangeal arthrodesis and/or plantar fascia section. 2 patients underwent a secondary procedure: subtalar arthrodesis due to persistence of the varus deformity, and a lengthening of the extensor hallux longus due to initial undercorrection. The mean follow-up was 42 months. Significant differences (p = 0.003) were observed between the pre-surgical AOFAS and at 12 months postoperatively (37.25 vs. 86.5). 75% of the patients reported «excellent» or «good» satisfaction after surgery. All radiographic parameters showed significant improvement.

CONCLUSIONS

The combination of the aforementioned surgical techniques for the cavovarus foot in CMT results in adequate functionality, good radiological correction and a high degree of satisfaction, avoiding primary arthrodescent surgery.

A prospective study on surgical management of foot deformities in Charcot Marie tooth disease

Foot deformities are frequently observed in patients with Charcot Marie tooth disease (CMT) and orthopaedic surgery is often required. Currently there is no evidence-based guideline on surgical management and only a few studies which have evaluated long-term outcomes of surgical procedures. The aim of the study was to evaluate longitudinally the effect of foot surgery in a cohort of CMT patients. Twenty-five CMT adult patients were assessed using a comprehensive group of validated scales and questionnaires before and after surgery. A wide range of surgical procedures was performed by one team of dedicated foot ankle orthopaedic surgeons. Foot alignment as measured by the foot posture index, pain, quality of life and callosities significantly improved after one year and the improvement was maintained up to 4 years after surgery. There was a trend towards a reduction in the number of falls post-operatively. Surgery had no effect on fatigue, balance and CMT examination score. Our findings showed significant improvement of pain, foot alignment, callosities and quality of life after surgery and suggested that foot deformity correction in adults with CMT performed in a specialised foot and ankle unit is beneficial.

Charcot-Marie-Tooth Disease and Other Hereditary Neuropathies

PURPOSE OF REVIEW

This article provides an overview of Charcot-Marie-Tooth disease (CMT) and other inherited neuropathies. These disorders encompass a broad spectrum with variable motor, sensory, autonomic, and other organ system involvement. Considerable overlap exists, both phenotypically and genetically, among these separate categories, all eventually exhibiting axonal injury and neurologic impairment. Depending on the specific neural and non-neural localizations, patients experience varying morbidity and mortality. Neurologic evaluations, including neurophysiologic testing, can help diagnose and predict patient disabilities. Diagnosis is often complex, especially when genetic and acquired components overlap.

RECENT FINDINGS

Next-generation sequencing has greatly improved genetic diagnosis, with many third-party reimbursement parties now embracing phenotype-based panel evaluations. Through the advent of comprehensive gene panels, symptoms previously labeled as idiopathic or atypical now have a better chance to receive a specific diagnosis. A definitive molecular diagnosis affords patients improved care and counsel. The new classification scheme for inherited neuropathies emphasizes the causal gene names. A specific genetic diagnosis is important as considerable advances are being made in gene-specific therapeutics. Emerging therapeutic approaches include small molecule chaperones, antisense oligonucleotides, RNA interference, and viral gene delivery therapies. New therapies for hereditary transthyretin amyloidosis and Fabry disease are discussed.

SUMMARY

Comprehensive genetic testing through a next-generation sequencing approach is simplifying diagnostic algorithms and affords significantly improved decision-making processes in neuropathy care. Genetic diagnosis is essential for pathogenic understanding and for gene therapy development. Gene-targeted therapies have begun entering the clinic. Currently, for most inherited neuropathy categories, specific symptomatic management and family counseling remain the mainstays of therapy.