Use of transcranial motor evoked potentials (TcMEPs) in spine deformity surgery in a case of Charcot-Marie-tooth disease-what we should know? A case report.

INTRODUCTION: Charcot Marie tooth disease (CMTD) is also known as Hereditary sensory motor neuropathy. It poses difficulties in attaining intra-operative neuromonitoring signals for deformity correction surgery. In this case report, we intent to mention key points for obtaining good neuromonitoring signals in these cases which increases the safety in scoliosis surgery. CASE PRESENTATION: We present a 14-year-old boy, known case of CMTD, presented with progressive deformity of the back. The child was wheelchair-bound and could walk only a few steps with support. He was unable to maintain a sitting balance without using upper limbs making him functionally quadriparatic. The radiographs showed a double scoliotic curve with costo-pelvic impingement. At the onset, no signals were obtained with routine intra-operative neuromonitoring settings. DISCUSSION: Increasing the sweep length and voltage in our neuro-monitors helped in acquiring the baseline signals and we went ahead to proceed the deformity correction.

Cochlear implantation in patients with Charcot-Marie-Tooth disease: two cases with a review of the literature.

PURPOSE: To report two cases of bilateral cochlear implantation (CI) in Charcot-Marie-Tooth disease (CMT) patients with novel mutations. Furthermore, we conducted a detailed literature review on the profile and outcomes of CI in this uncommon clinical circumstance. CASE PRESENTATION: Case 1 involved a 25-year-old woman who was referred for sudden hearing loss (HL) in her left ear and had a 7-year history of HL in her right ear. She was diagnosed with CMT type 1 with a thymidine phosphorylase gene mutation. CI was performed on her left side because her hearing gradually worsened to deafness in both ears. At 3 months post-operation, her speech discrimination score without lip-reading improved from 0 to 100%. She underwent a second CI on her right ear 6 months after her first CI. Two years from her first operation, the speech discrimination score was 100%. Case 2 received her first CI on her right ear at the age of nine for her bilateral HL. She was diagnosed with CMT type 2 with a Twinkle mitochondrial DNA helicase gene mutation. Preoperatively, the speech discrimination score in both ear-aided conditions was 70%. At the 7-year post-operation follow-up, the speech discrimination score was 76%. A second CI was performed due to decreasing hearing ability in her left ear. The speech discrimination score showed 100% at 7 months after the second CI. CONCLUSIONS: CI is an effective hearing rehabilitation option for CMT patients with severe-to-profound SNHL. Neuro-otologists should consider CI as a treatment option, even though hearing loss in CMT is associated with auditory neuropathy spectrum disease (ANSD).

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.

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.

Regional anesthesia in patients with Charcot-Marie-Tooth disease: a historical cohort study of 53 patients.

PURPOSE: Anesthetic management for patients with Charcot-Marie-Tooth disease (CMT) is controversial. Description of the use of regional anesthesia (RA) in patients with CMT is limited. Regional anesthesia has traditionally been avoided because of risk of nerve injury. We retrospectively reviewed patients with CMT who received RA at our institution. METHODS: We performed a historical cohort study of all patients with CMT who received RA from 30 April 2010 to 30 April 2020 within our institution. Charts were reviewed for information on demographics, RA procedures, perioperative variables, evidence of neurologic complications, post-RA neurology consults, and perioperative electromyography (EMG) results. Electromyographs were reviewed by a neurologist who was blinded to the surgical and RA details. RESULTS: Fifty-three patients received a total of 132 regional anesthetics during the study period. Twenty-five patients received RA on more than one occasion. Fifty-five EMGs and 14 postoperative neurology consults were performed. Two patients had neurology consults with peripheral nerve block (PNB) distribution complaints years later. Neither attributed the complaints to the PNB. The other neurology consults were for unrelated complaints. No EMG results suggested injury related to PNB. CONCLUSION: This study found no evidence of documented neurologic complications or an increased risk of nerve injury related to RA in CMT patients.

RéSUMé: OBJECTIF: La prise en charge anesthésique des patients atteints de la maladie de Charcot-Marie-Tooth (CMT) est controversée. Les descriptions de l'utilisation de l'anesthésie régionale (AR) chez les patients atteints de CMT sont limitées. L'anesthésie régionale est traditionnellement évitée en raison du risque de lésion nerveuse. Nous avons rétrospectivement passé en revue les dossiers des patients atteints de CMT ayant reçu une AR dans notre établissement. MéTHODE: Nous avons réalisé une étude de cohorte historique de tous les patients atteints de CMT ayant reçu une AR entre le 30 avril 2010 et le 30 avril 2020 au sein de notre établissement. Les dossiers ont été passés en revue pour en tirer des renseignements sur les données démographiques, les interventions d'AR, les variables périopératoires, les signes de complications neurologiques, les consultations en neurologie post-AR et les résultats de l'électromyographie (EMG) périopératoire. Les électromyographes ont été examinés par un neurologue qui n'avait pas accès aux détails concernant la chirurgie et l'AR. RéSULTATS: Cinquante-trois patients ont reçu un total de 132 anesthésies régionales au cours de la période d'étude. Vingt-cinq patients ont reçu une AR à plus d'une occasion. Cinquante-cinq EMG et 14 consultations postopératoires en neurologie ont été effectuées. Deux patients ont consulté en neurologie après s'être plaints de la distribution du bloc nerveux périphérique (BNP) des années plus tard. Ni l'un ni l'autre n'a attribué ces problèmes au BNP. Les autres consultations en neurologie concernaient des plaintes non liées au BNP. Aucun résultat d'EMG n'a suggéré de lésion liée au BNP. CONCLUSION: Cette étude n'a trouvé aucune preuve de complications neurologiques documentées ou d'un risque accru de lésion nerveuse liée à l'AR chez les patients atteints de CMT.

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.

Abnormal Bone Morphology in Charcot-Marie-Tooth Disease.

BACKGROUND: Although long suspected, it has yet to be shown whether the foot and ankle deformities of Charcot-Marie-Tooth disease (CMT) are generally associated with abnormalities in osseous shape. Computed tomography (CT) was used to quantify morphologic differences of the calcaneus, talus, and navicular in CMT compared with healthy controls. METHODS: Weightbearing CT scans of 21 patients (27 feet) with CMT were compared to those of 20 healthy controls. Calcaneal measurements included radius of curvature, sagittal posterior tuberosity-posterior facet angle, and tuberosity coronal rotation. Talar measurements included axial and sagittal body-neck declination angle, and coronal talar head rotation. Surface-mesh model analysis of the hindfoot was performed comparing the average of the CMT cohort to the controls using a CT analysis software (Disior Bonelogic 2.0). Means were compared with a t test (P < .05). RESULTS: CMT patients had significantly less talar sagittal declination vs controls (17.8 vs 25.1 degrees; P < .05). Similarly, CMT patients had less talar head coronal rotation vs controls (30.8 vs 42.5 degrees; P < .001). The calcaneal radius of curvature in CMT patients was significantly smaller than controls (822.8 vs 2143.5 mm; P < .05). CMT sagittal posterior tuberosity-posterior facet angle was also significantly different from that of controls (60.3 vs 67.9 degrees respectively; P < .001).Surface-mesh model analysis demonstrated the largest differences in morphology at the navicular tuberosity, medial talar head, sustentaculum tali, and anterior process of the calcaneus. CONCLUSION: This is the first study to quantify the morphologic differences in hindfoot osteology seen in CMT patients. Patients identified with osseous changes of the calcaneus, especially a smaller axial radius of curvature, may benefit from a 3-dimensional osteotomy for correction.

A Patient With Kearns Sayre Syndrome and Charcot-Marie-Tooth for Supraventricular Tachycardia Ablation: A Case Report.

Kearns Sayre syndrome (KSS) is a rare mitochondrial myopathy that is associated with progressive impaired ventilatory drive, heart block, and peripheral neuropathy. Charcot-Marie-Tooth disease (CMT) is a rare chronic motor and sensory peripheral neuropathy which includes muscle weakness and restrictive pulmonary impairment. Patients with either condition having anesthesia can have postoperative respiratory failure. We report a 52-year-old man diagnosed with variants of KSS and CMT presenting for supraventricular tachycardia (SVT) ablation. This is the first report of successful perioperative management of a general anesthetic in a patient with both KSS and CMT.

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.

Long-term walking ability and patient satisfaction after lower limb functional surgery in patients affected by Charcot-Marie-Tooth disease: A retrospective study.

Structural foot deformities consequent to Charcot Marie Tooth (CMT) can be treated by functional surgery (FS). This study aims to evaluate both long-term walking ability and patients' satisfaction in CMT subjects who underwent FS during their lifetime. We conducted a retrospective observational study. Age, sex, CMT type, comprehensive surgical history, current walking ability assessed by the Walking Handicap Scale (WHS) and patients' global impression of change (pGIC) were retrieved from a custom database managed at our institution. WHS and pGIC were assessed between mid-2018 and mid-2019. Data from 79 patients were screened and 63 were included, 35W-28M, mean age 42 (15), with demyelinating (75%), axonal (20%), and other types (5%) of CMT, who underwent FS between 1967 and 2018. FS evolved significantly over the years from bone-related procedures (e.g., arthrodesis) to both bone and soft tissues-related procedures. The re-intervention rate decreased from 70% before 2000 to 32% in the last decade. Complications arose in five cases. FS was mainly performed on adults (73%). WHS was ≥ 5 in three-quarters of the sample (range 1-6) and was significantly affected by age groups in patients with demyelinating CMT (n=47, p<0.01, non-parametric ANOVA). Nearly 80% of patients were satisfied with FS (pGIC ≥ 4). In conclusion, CMT subjects who underwent FS surgery maintained a high gait efficiency in the long-term period, with middle to high levels of satisfaction in the majority of the cases. This confirms the validity of FS in the management of acquired foot deformities in CMT patients.

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

BACKGROUND: Charcot-Marie-Tooth (CMT) disease is a hereditary motor-sensory neuropathy that is often associated with a cavovarus foot deformity. Limited evidence exists for the orthopedic management of these patients. Our goal was to develop consensus guidelines based upon the clinical experiences and practices of an expert group of foot and ankle surgeons. METHODS: Thirteen experienced, board-certified orthopedic foot and ankle surgeons and a neurologist specializing in CMT disease convened at a 1-day meeting. The group discussed clinical and surgical considerations based upon existing literature and individual experience. After extensive debate, conclusion statements were deemed "consensus" if 85% of the group were in agreement and "unanimous" if 100% were in support. CONCLUSIONS: The group defined consensus terminology, agreed upon standardized templates for history and physical examination, and recommended a comprehensive approach to surgery. Early in the course of the disease, an orthopedic foot and ankle surgeon should be part of the care team. This consensus statement by a team of experienced orthopedic foot and ankle surgeons provides a comprehensive approach to the management of CMT cavovarus deformity. LEVEL OF EVIDENCE: Level V, expert opinion.

The suspected SARS-Cov-2 infection in a Charcot-Marie-Tooth patient undergoing postsurgical rehabilitation: the value of telerehabilitation for evaluation and continuing treatment.

We report, to the best of our knowledge, the first case of a probable COVID-19 infection in a 28-year-old man with Charcot-Marie-Tooth disease. The diagnosis was established through a remote interaction with the patient after early discharge from outpatient therapy due to upcoming traveling restrictions. The COVID-19 disease appeared mild, without major respiratory problems, and no obvious neuromuscular deterioration was reported or observed. Telerehabilitation provided an opportunity to continue with hand rehabilitation after tendon transfer surgery, perform an ad-hoc online evaluation, and advise the patient how to prevent the spread of infection and cope with restrictions limiting outpatient visits. This experience seems valuable for further development of telerehabilitation in anticipation of future pandemics or adversarial events since it allows reaching out to patients unable to travel and overcomes the need for regular outpatient visits.

Closed arthrodesis in infected neuropathic ankles using Ilizarov ring fixation.

AIMS: Infected and deformed neuropathic feet and ankles are serious challenges for surgical management. In this study we present our experience in performing ankle arthrodesis in a closed manner, without surgical preparation of the joint surfaces by cartilaginous debridement, but instead using an Ilizarov ring fixator (IRF) for deformity correction and facilitating fusion, in arthritic neuropathic ankles with associated osteomyelitis. METHODS: We retrospectively reviewed all the patients who underwent closed ankle arthrodesis (CAA) in Ilizarov Scientific Centre from 2013 to 2018 (Group A) and compared them with a similar group of patients (Group B) who underwent open ankle arthrodesis (OAA). We then divided the neuropathic patients into three arthritic subgroups: Charcot joint, Charcot-Maire-Tooth disease, and post-traumatic arthritis. All arthrodeses were performed by using an Ilizarov ring fixator. All patients were followed up clinically and radiologically for a minimum of 12 months to assess union and function. RESULTS: The union rate for Group A was 81% (17/21) while it was 84.6% (33/39) for Group B. All the nonunions in Group A underwent revision with an open technique and achieved 100% union. Mean duration of IRF was 71.5 days (59 to 82) in Group A and 69 days (64.8 to 77.7) in Group B. The American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score was similar in both groups. The postoperative hospital stay was shorter in Group A (21 days (SD 8)) than Group B (28 days (SD 9)). In the latter Group there were more problems with wound healing and greater requirement for antibiotic treatment. The mean operating time was 40 minutes (SD 9) in Group A compared to 80 minutes (SD 13) in Group B. Recurrence of infection occurred in 19% (4/21) and 15.5% (6/39) for Group A and Group B respectively. CONCLUSION: We found CAA using an IRF to be an effective method for ankle arthrodesis in infected neuropathic foot and ankle cases and afforded comparable results to open methods. Due to its great advantages, Ilizarov method of CAA should always be considered for neuropathic ankles in suitable patients. Cite this article: Bone Joint J 2020;102-B(4):470-477.

Extensor Tendon Transfers for Treatment of Foot Drop in Charcot-Marie-Tooth Disease: A Biomechanical Evaluation.

BACKGROUND: In Charcot-Marie-Tooth (CMT) disease, selective weakness of the tibialis anterior muscle often leads to recruitment of the long toe extensors as secondary dorsiflexors, with subsequent clawing of the toes. Extensor hallucis longus (EHL) and extensor digitorum longus (EDL) tendon transfers offer the ability to augment ankle dorsiflexion and minimize claw toe deformity. The preferred site for tendon transfer remains unknown. Our goal was to quantify ankle dorsiflexion in the "intact" native tendon state, compared with tendon transfers to the metatarsal necks or the cuneiforms. We hypothesized that EHL and EDL transfers would improve ankle dorsiflexion as compared with the intact state and would produce similar motion when anchored at the metatarsal necks or cuneiforms. METHODS: Eight fresh-frozen cadaveric specimens transected at the midtibia were mounted into a specialized jig with the ankle held in 20 degrees of plantarflexion. The EHL and EDL tendons were isolated and connected to linear actuators with suture. Diodes secured on the first metatarsal, fifth metatarsal, and tibia provided optical data for tibiopedal position in 3 dimensions. After preloading, the tendons were tested at 25%, 50%, 75%, and 100% of maximal physiologic force for the EHL and EDL muscles, individually and combined. RESULTS: Transfers to metatarsal and cuneiform locations significantly improved ankle dorsiflexion compared with the intact state. No difference was observed between these transfer sites. Following transfer, only 25% of maximal force by combined EHL and EDL was required to achieve a neutral foot position. CONCLUSION: Transfer of the long toe extensors, into either the metatarsals or cuneiforms, significantly increased dorsiflexion of the ankle. CLINICAL RELEVANCE: The transferred extensors can serve a primary role in treating foot drop in CMT disease, irrespective of the presence of clawed toes. This biomechanical study supports tendon transfers into the cuneiforms, which involves less time, fewer steps, and easier tendon balancing without compromising dorsiflexion power.

Lessons From Leprosy: Peripheral Neuropathies and Deformities in Chronic Demyelinating Diseases.

In light of the World Health Organization's push to accelerate progress toward a leprosy-free world by 2020, it is fitting to look back on the evolution of progress in treating lepromatous neuropathy and limb deformities. To date, no surgeon has had as great an impact on the understanding and treatment of this disease as Dr Paul Brand. Before Dr Brand's accomplishments, few surgeons participated in the management of the deformed leprous patient. By challenging conventional beliefs, Dr Brand revealed that many of the deformities associated with leprosy were in fact caused by nerve damage and subsequent limb anesthesia. His pioneering work centered on tendon transfers to provide hand and foot mobility to leprous patients, revolutionizing the surgical management of this patient population and restoring functionality to the lives of otherwise stigmatized and functionally handicapped individuals. In the process, he provided us with the surgical principles and techniques that we still apply today. Because of its predilection for the peripheral nervous system, leprosy also provides an excellent opportunity to investigate mechanisms of demyelination and chronic nerve degeneration in nonacute peripheral neuropathies. Processes underlying demyelination of infectious, traumatic, and genetic etiologies overlap and precede the onset of acute neuronal derangement. Glial pathology has been shown to be a common pathological element in leprosy, Charcot-Marie-Tooth type I, multiple sclerosis, and chronic nerve compression injury. The aim of this article is to provide an overview of lepromatous neuropathy with its subsequent deformities as it relates to the pathophysiology, surgical management, and potential therapeutic targets of other modern peripheral neuropathies.

Comparison of Lateralizing Calcaneal Osteotomies for Varus Hindfoot Correction.

BACKGROUND: There is limited consensus on the optimal operative technique for correcting heel varus in patients with Charcot-Marie-Tooth (CMT) disease. This comparative study evaluated the ability of 4 lateralizing calcaneal osteotomies, with and without Dwyer wedge resection and coronal rotation of the posterior tuberosity, to correct severe heel varus. METHODS: The computed tomography (CT) scan of a teenage CMT patient with severe hindfoot varus was used to create 3-dimensional (3D)-printed models of the talus, calcaneus, and cuboid. A custom jig facilitated precise replication of the osteotomy cuts. Four different configurations were created: oblique osteotomy with lateralization, oblique osteotomy with lateralization and internal rotation of the posterior tuberosity, Dwyer wedge resection with lateralization, and Dwyer wedge resection with lateralization and internal rotation. CT scans were performed on each model before and after osteotomy. Statistical analysis was used to evaluate differences in several predefined radiographic parameters. RESULTS: The sequential transformations generated increasing lateral translation of the weight-bearing calcaneus. Dwyer wedge osteotomy significantly improved lateralization (effect = 8.0 mm), valgus hindfoot angle (effect = 6.1 degrees), and coronal calcaneal tilt (effect = -17.6 degrees) compared with the oblique osteotomy. Internal rotation of the posterior tuberosity further improved lateralization (effect = 3.3 mm), valgus hindfoot angle (effect = 2.5 degrees), and coronal calcaneal tilt (effect = -11.7 degrees). Dwyer osteotomy models had on average 5-mm shorter posterior tuberosity lengths than the oblique osteotomies. The addition of rotation did not significantly affect length. CONCLUSIONS: Significant lateralization of the posterior tuberosity was achieved in all transformations. The Dwyer wedge osteotomy improved hindfoot valgus angle, coronal calcaneal tilt, and lateralization of the weight-bearing surface compared with oblique osteotomy. Posterior tuberosity internal rotation further lateralized the plantar surface and normalized weight bearing. Lateralization, combined with Dwyer osteotomy and coronal plane internal rotation, achieved the greatest correction of varus heel. CLINICAL RELEVANCE: This study compares multiple lateralizing calcaneal osteotomies and proposes a combined technique of lateralization, Dwyer wedge resection, and coronal plane rotation to address advanced cavovarus hindfoot deformities.