A Consensus Statement on the Surgical Treatment of Charcot-Marie-Tooth Disease

Outcomes of Charcot-Marie-Tooth Disease Cavovarus Surgical Reconstruction

BACKGROUND

Charcot-Marie-Tooth (CMT) disease is a progressive inherited neurologic disorder causing muscle weakness and lower extremity deformity. The goal of foot and ankle surgical treatment is to create a stable, plantigrade foot, with the potential elimination of brace-wear for ambulation. The aim of this study was to report baseline CMT patient function and subsequent outcome improvement from surgical treatment, as determined by PROMIS physical function (PF), pain interference (PI), and mental health/depression (D) scores.

METHODS

Retrospective data were collected on consecutive CMT patients older than 18 years receiving surgical treatment by a single surgeon from 2018 to 2022 with minimum 1-year follow-up. Each patient prospectively completed PROMIS preoperatively and postoperatively after all planned surgical treatment was completed. Prospective clinical and radiographic data were collected to describe complications and correlation to outcome.

RESULTS

Ninety-five feet in 64 patients older than 18 years were included for analysis. Mean follow-up was 21 months (range, 12-31) with 100% minimum 1-year follow-up. CMT patients had worse preoperative and baseline scores in all domains except PROMIS-D compared with population normal PROMIS scores. Significant improvements were identified in all PROMIS domains following surgical treatment. The mean PROMIS-PF score increased (40 to 45, delta = 4.9, P < .001), the mean PROMIS-PI score decreased (59 to 52, delta = 7.1, P < .001), and the mean PROMIS-D score decreased (50 to 47, delta = 3.0, P = .004). Subgroup analysis was performed for patients with severe radiographic deformity and those treated with arthrodesis in an attempt to demonstrate the impact of disease severity on outcome. Subgroup analysis demonstrated that arthrodesis led to worse overall PROMIS-PF outcome with the same change score.

CONCLUSION

Surgical treatment for CMT patients provides significant clinical improvement in all measured outcome domains. CMT patients can be restored to normal population physical function and pain interference outcome scores. Patients with more severe deformity have similar improvement from surgical treatment, although their ultimate functional improvement is blunted due to a lower baseline.

Current Treatment Methods for Charcot-Marie-Tooth Diseases

Charcot-Marie-Tooth (CMT) disease, the most common inherited neuromuscular disorder, exhibits a wide phenotypic range, genetic heterogeneity, and a variable disease course. The diverse molecular genetic mechanisms of CMT were discovered over the past three decades with the development of molecular biology and gene sequencing technologies. These methods have brought new options for CMT reclassification and led to an exciting era of treatment target discovery for this incurable disease. Currently, there are no approved disease management methods that can fully cure patients with CMT, and rehabilitation, orthotics, and surgery are the only available treatments to ameliorate symptoms. Considerable research attention has been given to disease-modifying therapies, including gene silencing, gene addition, and gene editing, but most treatments that reach clinical trials are drug treatments, while currently, only gene therapies for CMT2S have reached the clinical trial stage. In this review, we highlight the pathogenic mechanisms and therapeutic investigations of different subtypes of CMT, and promising therapeutic approaches are also discussed.

Anterior or Posterior Tibial Tendon Transfer to the Peroneus Tertius for Equinovarus Deformity

BACKGROUND

Equinovarus deformity correction was performed by soft tissue release and bone deformity correction, and tendon transfer to maintain deformity correction. Because of the high complication rate of tendon fixation methods, partial or total anterior tibial tendon or posterior tibial tendon transfer to the peroneus tertius tendon was reported. The purpose of this study was (i) to review the results of this tendon transfer technique after release and correction of talipes equinovarus, and (ii) to analyze the complication of this technique.

METHODS

Between February 2017 and May 2022, 176 patients (210 feet) with equinus and/or varus foot and ankle deformities underwent anterior or posterior tibial tendon transfer to the peroneus tertius in our institute. Preoperative and postoperative foot and ankle range of motion (passive and active) were checked. The postoperative radiographic assessment included antero-posterior (AP), lateral, and hindfoot alignment radiographs. Preoperative and postoperative lateral tibio-talar, talo-calcaneal, talo-first metatarsal, tibial-sole angles, hindfoot alignment, and anterior subluxation of the talus were checked. The American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale, and visual analog scale (VAS) were used to assess pain. Paired Student's t-test was used to compare the clinical scores and radiographic angles before the operation and at the last follow-up.

RESULTS

The mean age of the patients was 23.27 ± 13.44 years (range, 3-69 years). The mean follow-up time was 25.56 ± 16.37 months (range, 12-68 months). There were significant differences between the preoperative and postoperative measurements of the lateral tibio-talar angle, lateral talo-calcaneal angle, lateral talo-first metatarsal angle, lateral tibial-sole angle, and hindfoot alignment (p < 0.001). There was significant difference between the preoperative and postoperative AOFAS and VAS scores (p < 0.001). The early complications included infection in one patient, skin necrosis in two patients, and plantar numbness in three patients. The late complications included pin infection in three patients, tibio-talar joint compression in four patients, forefoot pain in two patients, toe flexion in two patients, and plantar numbness in one patient. There were three cases of complications (1.43%) related to the transferred tendons.

CONCLUSION

Tibialis anterior or posterior tendon transfer to the peroneus tertius is a safe and effective method for equinovarus deformity correction. It yielded excellent outcomes that produced high patient satisfaction and few complications.

Is a Plantarflexed First Ray the Primary Deformity In Children With Cavovarus Feet Secondary to Charcot-Marie-Tooth Disease? A Pedobarographic Analysis

BACKGROUND

Charcot-Marie-Tooth disease (CMT) is a common cause of cavovarus foot deformity in children. This deformity is often quoted as being forefoot driven, with a primary deformity of first ray plantarflexion driving the hindfoot into varus by virtue of the tripod effect of the foot, which was hypothesized by Coleman and is commonly assessed clinically using his eponymous block test. The primary goal of this study was to objectively investigate this hypothesis using dynamic pedobarography.

METHODS

A review of the gait lab archives at a large tertiary referral center was carried out to identify children with CMT who had foot photos and dynamic pedobarographic data. Two orthopaedic surgeons then determined the weight-bearing hindfoot alignment of these children using clinical photography. The order of contact during gait of the first metatarsal relative to the fifth metatarsal was then obtained from the dynamic pedobarographic data.

RESULTS

One hundred eighteen feet from 60 children with CMT met the study inclusion criteria. Sixty-eight varus feet were compared with 50 nonvarus feet. First ray contact occurred before fifth ray contact in only 39.7% of the varus feet compared with 34.0% of the nonvarus feet, which did not meet statistical significance (P=0.526).

CONCLUSIONS

In this cohort, dynamic pedobarography did not consistently demonstrate the first metatarsal contact occurring before the fifth metatarsal contact in children with varus feet secondary to CMT. While nearly 40% of the feet did make initial contact on the first ray, 60% of the feet landed in varus before the first ray made contact, leading us to believe that the foot is prepositioned in varus. This may be in part due to the progressive muscle imbalance and secondary deformity that has occurred. Surgical management of these children should take this.

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.

Forefoot Morphotypes in Cavovarus Feet: A Novel Assessment of Deformity

BACKGROUND

The cavovarus foot is a complex 3-dimensional deformity. Although a multitude of techniques are described for its surgical management, few of these are evidence based or guided by classification systems. Surgical management involves realignment of the hindfoot and soft tissue balancing, followed by forefoot balancing. Our aim was to analyze the pattern of residual forefoot deformities once the hindfoot is corrected, to guide forefoot correction.

METHODS

We included 20 cavovarus feet from 16 adult patients with Charcot-Marie-Tooth who underwent weightbearing CT (mean age 43.4 years, range: 22-78 years, 14 males). Patients included had flexible deformities, with no previous surgery. Using specialized software (Bonelogic 2.1, Disior) a 3-dimensional, virtual model was created. Using morphologic data captured from normal feet in patients without pathology as a guide, the talonavicular joint of the cavovarus foot was digitally reduced to a "normal" position to simulate the correction that would be achieved during surgical correction. Models of the corrected position were exported and geometrically analyzed using Blender 3.64 to identify anatomical trends.

RESULTS

We identified 4 types of cavovarus forefoot morphotypes. Type 0 was defined as a balanced forefoot (2 cases, 10%). Type 1 was defined as a forefoot where the first metatarsal was relatively plantarflexed to the rest of the foot, with no significant residual adduction after talonavicular joint correction (12 cases, 60%). Type 2 was defined as a forefoot where the second and first metatarsals were progressively plantarflexed, with no significant adduction (4 cases, 20%). Type 3 was defined as a forefoot where the metatarsals were adducted after talonavicular derotation (2 cases, 10%).

CONCLUSION

In this relatively small cohort, we identified 4 forefoot morphotypes in cavovarus feet that might help surgeons to recognize and anticipate the residual forefoot deformities after hindfoot correction. Different treatment strategies may be required for different morphotypes to achieve balanced correction.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

3D Analysis of Joint-Sparing Charcot-Marie-Tooth Surgery Effect on Initial Standing Foot Alignment

BACKGROUND

The complex deformities in cavovarus feet of Charcot-Marie-Tooth (CMT) disease are difficult to evaluate. The aim of this study was to quantify the initial standing alignment correction achieved after joint-sparing CMT cavovarus reconstruction using pre- and postoperative weightbearing computed tomography (WBCT).

METHODS

Twenty-nine CMT cavovarus reconstructions were retrospectively analyzed. Three-dimensional measurements were performed using semiautomated software (Bonelogic 2.1) to investigate changes in sagittal, axial, and coronal parameters. Pre- and postoperative data were compared, along with normative data. Correlation among the preoperative measurements and the amount of correction in sagittal, axial, and coronal parameters were analyzed.

RESULTS

The sagittal, axial, and coronal malalignment of the hindfoot, and the sagittal and axial malalignment of the forefoot, was significantly improved after corrective surgery (P < .05). Sagittal Meary angle (from 14.8 to 0.1 degrees), axial talonavicular angle (TNA, from 3.6 to 19.2 degrees), and coronal hindfoot alignment (from 11.0 to -11.1 degrees) showed significant changes postoperatively (P < .001). Hindfoot, forefoot sagittal, and forefoot axial parameters reached comparable outcomes compared with normative value (P > .05). Regarding amount of correction, Spearman correlation demonstrated that axial Meary angle and TNA were most strongly related to improvement in sagittal Meary angle and coronal hindfoot alignment.

CONCLUSION

Preoperative and postoperative WBCT measurements demonstrated that joint sparing CMT cavovarus reconstruction significantly improved sagittal, axial, and coronal deformities of CMT, and sagittal Meary angle was restored toward normative values. Apparent axial plane correction, the majority of which occurred at the talonavicular joint, had the strongest correlation with deformity correction in multiple planes. This suggests that soft tissue releases and correction of the talonavicular joint may be a key component of a cavovarus foot correction.

Classifications in adult pes cavus - A scoping review

AIMS

The adult cavus foot represents a challenging clinical problem, with varied aetiology and complex, 3-dimensional deformities. Thus far, the cavus foot has eluded a unified classification. The aim of this paper was to appraise the literature to identify classification systems which guide the operative management of neurological cavus feet in adults.

METHODS

As the aim of this paper was broad, a scoping review was conducted. The review was conducted in line with published frameworks. Our principal research question was 'what classification systems that guide surgical management currently exist for neurological cavus feet in adults'. We searched CINAHL, Embase, OVID, Proquest, Pubmed, Scopus and Web of Science databases using MESH and non-MESH terms. Two authors independently reviewed abstracts / papers and a data extraction sheet was used to collect the relevant data.

RESULTS

A total of 1140 articles were initially screened, identifying 125 articles for which a full text review was performed. Only three articles met all our inclusion criteria. All these articles reported an anatomical classification with suggestions for treatment based on the classification. All were considered to comprise Level V evidence, and none reported outcomes of treatment based on the classification.

CONCLUSIONS

There is currently a paucity of robust classifications to guide treatment in neurological cavus feet in adults. The few classifications systems that exist are varied and do not as yet have sufficient evidence to support their widespread use. Further work is required, aimed at identifying specific features of cavus feet that would guide operative treatment.

Quantified fat fraction as biomarker assessing disease severity in rare Charcot-Marie-Tooth subtypes

Objective

Charcot-Marie-Tooth (CMT) disease is the most common inherited neuromuscular disorder. Multi-echo Dixon MRI technique is a highly sensitive method for quantifying muscle fatty infiltration, which may provide excellent value for the assessment of CMT. Due to the rareness of the disease, its use in CMT disease has been rarely evaluated, especially in subtypes.

Methods

Thirty-four CMT1 patients, 25 CMT2 patients, and 10 healthy controls were recruited. All of the recruited CMT1 patients are CMT1A with PMP22 duplication. Among CMT2 patients, 7 patients are CMT2A with MFN2 mutation, and 7 patients have SORD mutations. Multi-echo Dixon MRI imaging was performed. The fat fractions (FFs) of 5 muscle compartments of the leg were measured at proximal, middle, and distal levels by two specialized musculoskeletal radiologists. Comparisons between CMT1, CMT2, and genetically defined subtypes were conducted.

Results

A proximal-distal gradient (27.6 ± 15.9, 29.9 ± 19.7, and 40.5 ± 21.4, p = 0.015) with a peroneal predominance (p = 0.001) in fat distribution was observed in CMT1. Significant differences in the soleus muscle FFs at proximal (19.1 ± 14.7 vs. 34.8 ± 25.1, p = 0.034) and medial levels (23.5 ± 21 vs. 38.0 ± 25.6, p = 0.044) were observed between CMT1 and CMT2 patients. Between PMP2 duplication and MFN2 mutation group, a significant difference in the soleus muscle FF was also observed (23.5 ± 21.0 vs. 54.7 ± 20.2, p = 0.039). Prominent correlations of calf muscle FFs with functional scores were observed.

Discussion

Multi-echo Dixon MRI imaging is a valuable tool for assessing disease severity in CMT. The difference in patterns of fatty infiltration of CMT subtypes is first reported, which could provide references when making targeted training plans.

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.

Charcot-Marie-Tooth Disease: A Surgical Algorithm

In Charcot-Marie-Tooth (CMT) cavovarus surgery, a regimented approach is critical to create a plantigrade foot, restore hindfoot stability, and generate active ankle dorsiflexion. The preoperative motor examination is fundamental to the algorithm, as it is not only guides the initial surgical planning but is key in the decision making that occurs throughout the operation. Surgeons need to be comfortable with multiple techniques to achieve each surgical goal. There is no one operation that works for all patients with CMT. A plantigrade foot is the most important of the surgical goals as hindfoot stability and ankle dorsiflexion can be augmented with bracing.

The Surgical Correction of Cavovarus Deformity in Charcot-Marie-Tooth Disease

Charcot-Marie-Tooth (CMT) disease is the most commonly inherited neuropathy. CMT disease is a motor-sensory neuropathy with multiple genotypes. By comparison, the phenotypic expression is more uniform, with two main presentations. Most patients who need surgical care have progressive cavovarus foot deformity, with muscle imbalance causing a nonplantigrade foot, soft-tissue contractures, and abnormal bone morphology. Surgical treatment can be life-changing for these patients, allowing them to walk potentially brace free with more endurance and less pain. Early realignment procedures may reduce progression of joint arthritis. A minority of patients have diffuse paralysis below the knee. These patients are best treated with ground-reaction ankle-foot orthoses. This review article is based on the senior author's extensive experience with CMT, along with the limited evidenced-based literature.

Hereditary Neuropathies

OBJECTIVE

This article provides an overview of hereditary neuropathies, describes the different hereditary neuropathy subtypes and the clinical approach to differentiating between them, and summarizes their clinical management.

LATEST DEVELOPMENTS

Increasingly available clinical genetic testing has broadened the clinical spectrum of hereditary neuropathy subtypes and demonstrated a significant overlap of phenotypes associated with a single gene. New subtypes such as SORD -related neuropathy and CANVAS (cerebellar ataxia, neuropathy, vestibular areflexia syndrome) have emerged. The optimization of clinical management has improved gait and motor function in the adult and pediatric populations. Novel therapeutic approaches are entering clinical trials.

ESSENTIAL POINTS

Hereditary neuropathies constitute a spectrum of peripheral nerve disorders with variable degrees of motor and sensory symptoms, patterns of involvement, and clinical courses.

Assessing the coronal plane deformity in Charcot Marie Tooth Cavovarus feet using automated 3D measurements

BACKGROUND

This study assesses the coronal-plane deformities in cavovarus feet secondary to Charcot-Marie-Tooth disease (CMT) using Weightbearing-CT (WBCT) and semi-automated 3D-segmentation software.

METHODS

WBCTs from 30 CMT-cavovarus feet were matched to 30 controls and analysed using semi-automatic 3D-segmentation (Bonelogic, DISIOR). The software used automated cross-section sampling with subsequent straight-line representation of weighted centre points to calculate 3D axes of bones in the hindfoot, midfoot and forefoot. Coronal relationships of these axes were analysed. Supination/pronation of the bones in relation to the ground and within each joint were measured and reported.

RESULTS

The most significant deformity in CMT-cavovarus feet occurred at the talonavicular joint (TNJ) with 23 degrees more supination than normal feet (6.4 ± 14.5 versus 29.4 ± 7.0 degrees, p < 0.001). This was countered by relative pronation at the naviculo-cuneiform joints (NCJ) of 7.0 degrees (-36.0 ± 6.6 versus -43.0 ± 5.3 degrees, p < 0.001). Combined hindfoot varus and TNJ supination resulted in an additive supination effect not compensated by NCJ pronation. The cuneiforms in CMT-cavovarus feet were therefore supinated by 19.8 degrees to the ground relative to normal feet (36.0 ± 12.1 versus 16.2 ± 6.8 degrees, p < 0.001). The forefoot-arch and 1st metatarsal-ground angles demonstrated similar supination to the cuneiforms suggesting no further significant rotation occurred distally.

CONCLUSION

Our results demonstrate coronal plane deformity occurs at multiple levels in CMT-cavovarus feet. Majority of the supination arises at the TNJ, and this is partially countered by pronation distally, mainly at the NCJ. An understanding of the location of coronal deformities may help when planning surgical correction.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Charcot-Marie-Tooth Disease of the Foot and Ankle: Imaging Features and Pathophysiology

Charcot-Marie-Tooth disease (CMT) is the most common inherited peripheral polyneuropathy, resulting in length-dependent motor and sensory deficiencies. Asymmetric nerve involvement in the lower extremities creates a muscle imbalance, which manifests as a characteristic cavovarus deformity of the foot and ankle. This deformity is widely considered to be the most debilitating symptom of the disease, causing the patient to feel unstable and limiting mobility. Foot and ankle imaging in patients with CMT is critical for evaluation and treatment, as there is a wide range of phenotypic variation. Both radiography and weight-bearing CT should be used for assessment of this complex rotational deformity. Multimodality imaging including MRI and US is also important to help identify changes in the peripheral nerves, diagnose complications of abnormal alignment, and evaluate patients in the perioperative setting. The cavovarus foot is susceptible to distinctive pathologic conditions including soft-tissue calluses and ulceration, fractures of the fifth metatarsal, peroneal tendinopathy, and accelerated arthrosis of the tibiotalar joint. An externally applied brace can assist with balance and distribution of weight but may be appropriate for only a subset of patients. Many patients will require surgical correction, which may include soft-tissue releases, tendon transfers, osteotomies, and arthrodesis when necessary, with the goal of creating a more stable plantigrade foot. The authors focus on the cavovarus deformity of CMT. However, much of the information discussed may also be applied to a similar deformity that may result from idiopathic causes or other neuromuscular conditions. ^©RSNA, 2023 Quiz questions for this article are available through the Online Learning Center.

Severe equinus cavo-varus correction through triplanar tarsectomy and posterior tibial tendon transfer based on 3D-printed biomodel

Surgery for severe equine cavo-varus is complex and must be individualized. The interindividual phenotypic variability demands a personalized planning of each foot to be operated. The study's primary goal was to evaluate the function and satisfaction of a series of patients with severe equinus cavo-varus deformity who underwent a triplanar tarsectomy and transposition of the posterior tibial tendon in a single stage surgery after a patient specific 3D biomodel planning. A series of 12 feet (5 patients bilaterally) operated with this technique was analyzed. The cohort comprised 2 females (28.5 %) and 5 males (71.4 %). The median follow-up time was 38.5 months (interquartile range: 24.75-48.75). The Foot and Ankle Disability Index pre (median 32.85; interquartile range: 20-46) and postsurgery (median 72; interquartile range: 56-75.5) were collected and statistically significant differences were observed (p < 0.002). Furthermore, the main variable evaluated was obtaining a plantigrade stable foot. This was clinically evaluated and was achieved in all patients except 1 patient who presented a residual equinus of 5º. This study shows that triplanar tarsectomy and posterior tibial tendon transfer in a single surgical procedure after patient-specific 3D biomodel planning allows for improved function in patients with severe equinus cavus varus foot deformity.

Treatment of Charcot-Marie-Tooth neuropathies

Charcot-Marie-Tooth (CMT) is a heterogeneous group of inherited neuropathies that affect the peripheral nerves and slowly cause progressive disability. Currently, there is no effective therapy. Patients' management is based on rehabilitation and occupational therapy, fatigue, and pain treatment with regular follow-up according to the severity of the disease. In the last three decades, much progress has been made to identify mutations involved in the different types of CMT, decipher the pathophysiology of the disease, and identify key genes and pathways that could be targeted to propose new therapeutic strategies. Genetic therapy is one of the fields of interest to silence genes such as PMP22 in CMT1A or to express GJB1 in CMT1X. Among the most promising molecules, inhibitors of the NRG-1 axis and modulators of UPR or the HDACs enzyme family could be used in different types of CMT.

Hereditary neuropathy

The hereditary neuropathies, collectively referred as Charcot-Marie-Tooth disease (CMT) and related disorders, are heterogeneous genetic peripheral nerve disorders that collectively comprise the commonest inherited neurological disease with an estimated prevalence of 1:2500 individuals. The field of hereditary neuropathies has made significant progress in recent years with respect to both gene discovery and treatment as a result of next-generation sequencing (NGS) approach. These investigations which have identified over 100 causative genes and new mutations have made the classification of CMT even more challenging. Despite so many different mutated genes, the majority of CMT forms share a similar clinical phenotype, and due to this phenotypic homogeneity, genetic testing in CMT is increasingly being performed through the use of NGS panels. The majority of patients still have a mutation in one the four most common genes (PMP22 duplication-CMT1A, MPZ-CMT1B, GJB1-CMTX1, and MFN2-CMT2A). This chapter focuses primarily on these four forms and their potential therapeutic approaches.

Evaluation and Management of Cavus Foot in Adults: A Narrative Review

Objective: Cavus foot is a deformity defined by the abnormal elevation of the medial arch of the foot and is a common but challenging occurrence for foot and ankle surgeons. In this review, we mainly aim to provide a comprehensive evaluation of the treatment options available for cavus foot correction based on the current research and our experience and to highlight new technologies and future research directions. Methods: Searches on the PubMed and Scopus databases were conducted using the search terms cavus foot, CMT (Charcot–Marie–Tooth), tendon-transfer, osteotomy, and adult. The studies were screened according to the inclusion and exclusion criteria, and the correction of cavus foot was analyzed based on the current research and our own experience. At the same time, 3D models were used to simulate different surgical methods for cavus foot correction. Results: A total of 575 papers were identified and subsequently evaluated based on the title, abstract, and full text. A total of 84 articles were finally included in the review. The deformities involved in cavus foot are complex. Neuromuscular disorders are the main etiologies of cavus foot. Clinical evaluations including biomechanics, etiology, classification, pathophysiology and physical and radiological examinations should be conducted carefully in order to acquire a full understanding of cavus deformities. Soft-tissue release, tendon-transfer, and bony reconstruction are commonly used to correct cavus foot. Surgical plans need to be customized for different patients and usually involve a combination of multiple surgical procedures. A 3D simulation is helpful in that it allows us to gain a more intuitive understanding of various osteotomy methods. Conclusion: The treatment of cavus foot requires us to make personalized operation plans according to different patients based on the comprehensive evaluation of their deformities. A combination of soft-tissue and bony procedures is required. Bony procedures are indispensable for cavus correction. With the promotion of digital orthopedics around the world, we can use computer technology to design and implement cavus foot operations in the future.

Dynamic Supination in Congenital Clubfoot: A Modified Delphi Panel Approach to Standardizing Definitions and Indications for Treatment

BACKGROUND

Dynamic supination is a well-recognized cause of congenital clubfoot deformity relapse. However, there is no consensus on how to diagnose it and there are varied approaches in its management. This study aims to define dynamic supination and indications for treatment by presenting consensus from an international panel of experts using a modified Delphi panel approach.

METHODS

An international panel of 15 pediatric orthopaedic surgeons with clinical and research expertise in childhood foot disorders participated in a modified Delphi panel on dynamic supination in congenital clubfoot. Panelists voted on 51 statements using a 4-point Likert scale on dynamic supination, clinical indications for treatment, operative techniques, and postoperative casting and bracing. All panelists participated in 2 voting rounds with an interim meeting for discussion. Responses were classified as unanimous consensus (100%), consensus (80% or above), near-consensus (70% to 79%), and indeterminate (69% or less).

RESULTS

Consensus was achieved for 34 of 51 statements. Panelists agreed dynamic supination is present when the forefoot is supinated during swing phase of gait with initial contact on the lateral border of the foot. There was also agreement that dynamic supination results from muscle imbalance between the tibialis anterior and the peroneus longus and brevis. There was no consensus on observation of hindfoot varus in dynamic supination, operative indications for posterior release of the ankle joint, or incisional approach for tibialis anterior tendon transfer. Reference to the calcaneopedal unit concept, planes of movement, and phases of gait were deemed important factors for consideration when evaluating dynamic supination.

CONCLUSIONS

Consensus statements from the Delphi panel can guide diagnosis and treatment of dynamic supination in clubfoot deformity relapse, including clinical decision making regarding preoperative casting, surgical approach, and postoperative immobilization. Near-consensus and indeterminate statements may be used to direct future areas of investigation.

LEVEL OF EVIDENCE

Level V.

Clinical practice guideline for the management of paediatric Charcot-Marie-Tooth disease

BACKGROUND AND OBJECTIVES

Charcot-Marie-Tooth disease (CMT) is the most common inherited neuropathy and often presents during childhood. Guidelines for the optimal management of common problems experienced by individuals with CMT do not exist, for either children or adults. We formed the Paediatric CMT Best Practice Guidelines Consortium to develop evidence and consensus-based recommendations for the clinical management of children and adolescents with CMT, with the primary objective of promoting optimal, standardised care globally.

METHODS

Development of this clinical practice guideline involved a series of systematic reviews covering 10 clinical questions, modified Delphi methodology involving an international panel of clinicians to generate consensus where evidence did not exist, and application of the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach to evaluate the body of literature and formulate recommendations.

RESULTS

The final guideline includes three evidence-based and 31 consensus-based recommendations. They encompass the management of muscle weakness, balance and mobility impairment, sensory symptoms, muscle cramps, impaired upper limb function, respiratory impairment, maintenance of joint range of motion and non-surgical management of joint deformity. Consensus was not achieved in some management areas, reflecting differences in practice between clinicians and healthcare settings, and highlighting the need for further research.

CONCLUSIONS

This clinical practice guideline provides practical and implementable guidance on the management of common clinical problems experienced by children with CMT and advocates for improved access to multidisciplinary care. Successful dissemination and implementation of these recommendations will be critical in ensuring their application across multiple healthcare settings.

Cavovarus With a Twist: Midfoot Coronal and Axial Plane Rotational Deformity in Charcot-Marie-Tooth Disease

BACKGROUND

The cavovarus deformity of Charcot-Marie-Tooth (CMT) disease is often characterized by a paradoxical relationship of hindfoot varus and forefoot valgus. The configuration of the midfoot, which links these deformities, is poorly understood. Accurate assessment of 3-dimensional alignment under physiologic loadbearing conditions is possible using weightbearing computed tomography (WBCT). This is the first study to examine the rotational deformity in the midfoot of CMT patients and, thus, provide key insights to successful correction of CMT cavovarus foot.

METHODS

A total of 27 WBCT scans from 21 CMT patients were compared to control WBCTs from 20 healthy unmatched adults. CMT patients with a history of bony surgery, severe degenerative joint disease, or open physes in the foot were excluded. Scans were analyzed using 3-dimensional software. Anatomic alignment of the tarsal bones was calculated relative to the anterior-posterior axis of the tibial plafond in the axial plane, and weightbearing surface in the coronal plane.

RESULTS

Maximal rotational deformity in CMT patients occurred at the transverse tarsal joints, averaging 61 degrees of external rotation (supination), compared to 34 degrees among controls (P < .01). The talonavicular joint was also the site of peak adduction deformity in the midfoot, with an average talonavicular coverage angle measuring 12 degrees compared with -11 degrees in controls (P < .01).

CONCLUSION

This 3-dimensional WBCT analysis is the first to isolate and quantify the multiplanar rotational deformity in the midfoot of CMT patients. Compared with healthy unmatched control cases, CMT patients demonstrated increased axial plane adduction and coronal plane rotation at the talonavicular (TN) joint. These findings support performing soft tissue release at the TN joint to abduct and derotate the midfoot as a first step for targeted deformity correction.

LEVEL OF EVIDENCE

Level III, retrospective case-control study.

Safety and Efficacy of Postoperative Indwelling Popliteal Nerve Catheters for Outpatient Charcot-Marie-Tooth Surgery

BACKGROUND

Outpatient surgical deformity correction for Charcot-Marie-Tooth (CMT) disease is limited by effective postoperative pain control. Our previous institutional protocol for foot and ankle surgery in this population included preoperative single-injection nerve blocks, but patients often experienced uncontrolled pain when the block wore off postoperative day 0 or 1, resulting in high opioid requirements and unplanned emergency department visits. The use of ultrasonography-guided continuous nerve catheters in CMT patients has not previously been studied. We aimed to prospectively investigate the safety and efficacy of ultrasonography-guided indwelling popliteal catheters in CMT patients undergoing outpatient foot deformity correction surgery.

METHODS

Twenty CMT patients, average 28 (range 13-53) years old, undergoing reconstructive surgery by a single foot and ankle attending surgeon were consented for preoperative ultrasonography-guided popliteal catheters. This series included 24 total outpatient procedures; 4 were staged bilateral. Indwelling popliteal catheters were maintained on discharge, providing continuous infusion until postoperative day (POD) 3, and then self-discontinued. Patients were prescribed oxycodone 5 mg (60-80 pills) as needed for breakthrough pain. Outcomes collected included daily pain scores (0-10), an opioid pill count on POD 14, and patient satisfaction ratings. Neurologic evaluation by 5-point 10g Semmes-Weinstein monofilament testing was performed preoperatively and on POD 14.

RESULTS

There were no observed catheter-site infections or hematomas. Nine of the patients had pre-existing sensory deficits involving at least 2 areas on the 5-point monofilament test. Postoperative testing showed these deficits were unchanged and there were no instances of new sensory deficits. Postoperative pain scores were typically low, with median values (interquartile ranges [IQRs]) of 3.5 (2.0-5.0) on POD 1, 2.5 (2.0-5.0) on POD 2, and 2.5 (1.0-3.75) on POD 3. At POD 14, pain was 1.0 (0-1.0). Patients consumed a median of 25 oxycodone pills (IQR 8-43) over 2 weeks, less than half the prescribed number. Patient satisfaction was high. All patients reported they would choose to have a nerve catheter again for a similar surgery.

CONCLUSION

This cases series demonstrated that regional anesthesia using ultrasonography-guided indwelling popliteal catheters was safe and effective for pain control in CMT patients undergoing outpatient foot and ankle surgery. Opioid consumption was comparable to published rates following major bony procedures, and no patients required emergent treatment or hospital admission for uncontrolled pain. No new sensory deficits were detected and patients with underlying sensory deficits remained unchanged. Patients were highly satisfied.

LEVEL OF EVIDENCE

Level IV, case series.

Calcaneal osteotomy for hindfoot deformity

Calcaneal osteotomy is an extra-articular procedure used for conservative surgical treatment of hindfoot deformity. It has static, architectural and dynamic effects, reorienting the tuberosity action point of the digastric muscle formation of the sural triceps and plantar aponeurosis. Calcaneal osteotomies vary in location, form and displacement, but can be categorized as tuberosity osteotomy, acting on talar position, and cervical osteotomy, acting on Chopart joint-line orientation. We here describe the 3 main calcaneal osteotomies we use for hindfoot deformity: talar varus/valgus, valgus flatfoot, and midfoot abductus/adductus. In each case, we describe our technique, resulting from our responses to the difficulties we have had to deal with: medializing osteotomy: performed percutaneously to limit skin complications, and easily associated to cervical calcaneal osteotomy to manage valgus flatfoot; Hintermann cervical adduction osteotomy: providing excellent angular correction, while conserving a medial cortical hinge; lateralizingosteotomy: performed on a medial approach, to enhance translation capacity and prevent the acute tarsal tunnel syndrome with which we have been otherwise confronted. Correcting foot deformities involves complex, multi-dimensional, multi-tissue surgery that is risky as it concerns a segment with terminal vascularization. The present three techniques need to be mastered, as they are usually associated to other tendon and/or ligament reconstruction procedures, and tourniquet time is limited. LEVEL OF EVIDENCE: V; expert opinion.

Rocuronium-induced respiratory paralysis refractory to sugammadex in Charcot-Marie-Tooth disease

Purpose

Prolonged postoperative neuromuscular respiratory paralysis after administration of a nondepolarizing neuromuscular blocking agent is a serious concern during anesthetic management of patients with Charcot-Marie-Tooth disease (CMTD). Some recent reports have described rocuronium use without respiratory paralysis in CMTD patients when sugammadex was used for its reversal. We report a case in which an induction dose of rocuronium caused a prolonged respiratory paralysis in a patient with undiagnosed type 1A CMTD (CMT1A).

Clinical features

A 63-yr-old-male with an American Society of Anesthesiologists Physical Status score of III underwent a left hip arthroplasty under general anesthesia for osteoarthritis. Preoperative pulmonary function testing indicated a restrictive impairment. Anesthesia was induced with fentanyl, remifentanil, propofol, and 0.73 mg·kg^-1 of rocuronium. The train-of-four (TOF) count was 0 for the 273-min duration of surgery. After repeated doses of sugammadex failed to recover the TOF count and spontaneous respirations, a total of 1,200 mg (17.3 mg·kg^-1) of sugammadex, which was assumed to be a sufficient amount for capturing the residual rocuronium, was administered. Although the patient expressed that he was awake via eye blinking, he could not breathe. Thus, he was placed on mechanical ventilation for 18 hr after surgery. A postoperative neurology consultation revealed a delayed nerve conduction velocity of 20 m·sec^-1 and a mutated duplication of the PMP22 gene; a diagnosis of CMT1A was made.

Conclusions

Our case shows that rocuronium can cause a prolonged neuromuscular respiratory paralysis refractory to sugammadex in patients with CMT1A and impaired respiratory function. Our case may also indicate that restrictive pulmonary impairment and low nerve conduction velocity of 20 m·sec^-1 are predictive factors that cause prolonged neuromuscular respiratory paralysis refractory to sugammadex in CMT1A.

Challenges in Treating Charcot-Marie-Tooth Disease and Related Neuropathies: Current Management and Future Perspectives

There is still no effective drug treatment available for Charcot-Marie-Tooth neuropathies (CMT). Current management relies on rehabilitation therapy, surgery for skeletal deformities, and symptomatic treatment of pain; fatigue and cramps are frequent complaints that are difficult to treat. The challenge is to find disease-modifying therapies. Several approaches, including gene silencing, to counteract the PMP22 gene overexpression in the most frequent CMT1A type are under investigation. PXT3003 is the compound in the most advanced phase for CMT1A, as a second-phase III trial is ongoing. Gene therapy to substitute defective genes or insert novel ones and compounds acting on pathways important for different CMT types are being developed and tested in animal models. Modulation of the Neuregulin pathway determining myelin thickness is promising for both hypo-demyelinating and hypermyelinating neuropathies; intervention on Unfolded Protein Response seems effective for rescuing misfolded myelin proteins such as P0 in CMT1B. HDAC6 inhibitors improved axonal transport and ameliorated phenotypes in different CMT models. Other potential therapeutic strategies include targeting macrophages, lipid metabolism, and Nav1.8 sodium channel in demyelinating CMT and the P2X7 receptor, which regulates calcium influx into Schwann cells, in CMT1A. Further approaches are aimed at correcting metabolic abnormalities, including the accumulation of sorbitol caused by biallelic mutations in the sorbitol dehydrogenase (SORD) gene and of neurotoxic glycosphingolipids in HSN1.

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.

Functional results and quality of life after joint preserving or sacrificing surgery in Charcot-Marie-Tooth foot deformities

INTRODUCTION

The purpose of this study was to assess the functional results, quality of life, and complications in two groups of Charcot-Marie-Tooth (CMT) patients according to the type of surgical operations, joint preserving, or joint sacrificing surgery.

METHODS

Fifty-two feet in forty-six patients with CMT who had undergone surgical deformity correction were divided into two groups based on the main surgical procedure for the correction: Class I (joint preserving surgery) and class II (joint sacrificing surgery). Foot ankle disability index (FADI) and short form 12 version 2 (SF₁₂V₂₎ were documented pre-operative and 12 months post-operative. The complications of both groups were monitored with a mean follow-up time of 20.5 months (range, 13-71.5).

RESULTS

After surgical treatment, FADI scores showed differences (p=0.005) between both groups. The functional improvement was 29 (20-46; p<0.001) in class I and 10 (2-36; p=0.001) in class II. The patients in both groups acquired a better quality of life as demonstrated in physical component summary of SF12 but without statistically difference. Three feet needed reintervention in class I (two for cavovarus recurrence and one for hallux flexus) at the end of follow-up. In contrast, five feet needed a new operation for cavovarus recurrence, claw toes recurrence, and ankle osteoarthritis after the progression of the condition.

DISCUSSION

An early surgical intervention to neutralize the deforming forces in CMT patients could be a useful strategy to delay or prevent the need for extensive reconstruction and potential future complications.

CONCLUSION

Based on the type of surgical intervention in CMT patients, the joint preserving surgery in addition to soft tissue balancing procedures obtained better functional outcomes and lower rate of complications when compared to the group of joint sacrificing surgery.