Os Intermetatarseum: A Rare Variation of Great Relevance / Os Intermetatarseum: Una Rara Variación de Gran Relevancia

SUMMARY: The os intermetatarseum is an accessory bone located in the foot, usually between the first 2 metatarsals and the cuneiform bone. It can be presented as free, articulated or in a fused fashion. It is a very unusual variation found in less than 13 % of the population. A 27-year-old patient presented to the emergency service due to an ankle lesion. Physical exam showed pain and limited range of motion while supporting partial load. Radiographic imaging showed a bony trace near the base of the first and second metatarsals, diagnosed as the os intermetatarseum. Formation of this supernumerary bone begins as a separate ossification center. Most cases are asymptomatic; however, compression of the deep peroneal nerve branches by the os intermetatarseum can lead to pain. Some authors suggest that the presence of this bone may cause hallux valgus. The intermetatarseum can lead to diagnostic confusion, mainly related to Lisfranc fracture. Its origin is still little understood.

El os intermetatarseum es un hueso accesorio ubicado en el pie, generalmente entre los 2 primeros metatarsianos y el hueso cuneiforme. Puede presentarse de forma libre, articulada o fusionada. Es una variación muy inusual que se encuentra en menos del 13 % de la población. Paciente de 27 años que acude a urgencias por lesión en tobillo. El examen físico mostró dolor y rango de movimiento limitado mientras soportaba una carga parcial. Las imágenes radiológicas mostraron un rastro óseo cerca de la base del primer y segundo metatarsianos, diagnosticado como os intermetatarseum. La formación de este hueso supernumerario comienza como un centro de osificación separado. La mayoría de los casos son asintomáticos; sin embargo, la compresión de las ramas profundas del nervio fibular en el espacio intermetatarsiano puede provocar dolor. Algunos autores sugieren que la presencia de este hueso puede provocar hallux valgus. El hueso intermetatarsiano puede llevar a confusión diagnóstica, principalmente relacionada con la fractura de Lisfranc. Su origen aún es poco comprendido.

The Prevalence of Bunions in the Setting of Brachymetatarsia.

Brachymetatarsia is caused by premature closure of the physis and is characterized by a short metatarsal. Additional foot conditions may exist in patients presenting with brachymetatarsia, such as hallux valgus (HV). A retrospective study was performed to evaluate the prevalence of HV and brachymetatarsia in the ipsilateral foot. Ninety-seven feet with congenital brachymetatarsia were reviewed in a multi-study cohort of 66 patients who underwent surgical correction between January 2005 and August 2020 at a single institution. The group was comprised of 61 females and 5 males, with a mean age of 27 years. HV deformities were verified with standardized anteroposterior radiographs. HV was present in 29 of 97 feet for a prevalence of 30% in the feet with brachymetatarsia. Our results demonstrate a 30% prevalence of HV associated with brachymetatarsia. This information is helpful for foot and ankle surgeons managing brachymetatarsia to determine appropriate conservative or surgical management of this condition.

Brachymetatarsia: A Classification for Surgical Treatment.

Brachymetatarsia is a congenital osseous and soft tissue deformity of a ray(s) of the foot. Because there is no particular consensus of methodology of lengthening for brachymetatarsia, the authors introduce a comprehensive anatomic classification and a surgical guide to treatment of each classification type. This classification combines the number of the metatarsal(s) affected and the letter(s) indicating the type of brachymetatarsia deformity (A = axial deficiency of the metatarsal, B = bowing of the metatarsal, C = congruency of metatarsal phalangeal joint). This study reviewed of 300 brachymetatarsals in 166 patients. Fifty of the 166 (30%) patients had bilateral brachymetatarsia. Of the 300 metatarsals with brachymetatarsia, 64 (21%) were first metatarsals, 22 (7%) were second metatarsals, 28 (9%) were third metatarsals, 12 (4%) were fifth metatarsals, and 174 (58%) were fourth metatarsals. Classification types that were found was a total of 165 (55%) type A, a total of 6 (2%) type B, a total of 72 (24%) type AB, a total of 39 (13%) type AC, and a total of 18 (6%) type ABC. A total of 16 (10%) male and 150 (90%) female patients were evaluated. The mean preoperative amount of shortening of the metatarsal was 15 mm (range, 4-20 mm), as determined by the preoperative metatarsal parabola deficiency, equating to 30% of the preoperative metatarsal length. Brachymetatarsia is a complex congenital deformity which until now has not been critically analyzed. This study outlines a comprehensive brachymetatarsia classification system which provides an accurate diagnosis of the deformity and offers a surgical treatment algorithm.

The Role of the Shortened Proximal Phalanx in the Setting of Brachymetatarsia.

Brachymetatarsia is a condition in which a metatarsal bone does not grow out to full length. This is caused by premature physeal closure. The proximal phalanx associated with the shortened metatarsal helps achieve the natural parabola of the foot. A hypoplastic proximal phalanx is a common finding in patients with brachymetatarsia. The goal of this study was to determine the length of the proximal phalanx in the setting of brachymetatarsia, and how much the shortening is attributed to the clinically smaller toe. We performed a retrospective study to evaluate the length of the proximal phalanx in the shortened ray. After the metatarsal was brought out to the desired length of correction, the proximal phalanx was measured on radiographs. Ninety-seven feet with congenital brachymetatarsia were reviewed in a cohort of 66 patients who underwent surgical correction between January 2005 and February 2020 at a single institution. The group was comprised of 61 females and 5 males, with a mean age of 27.5 years. The average length of the proximal phalanx associated with the affected metatarsal was noted to be 18.9 ± 3.83 mm for males and 15.6 ± 4.02 mm for females. Our results indicate the shortened proximal phalanx is 5 mm shorter when compared to normal population and is a contributing factor to the shortened clinical appearance of the digit in brachymetatarsia. Treating surgeons should be aware of this to better educate patients on the influence of the digit on the overall shortening seen in cases of brachymetatarsia.

Subacute two stage metatarsal lengthening with gradual distraction for brachymetatarsia: A consecutive case series and literature review.

BACKGROUND: This study examined the functional and clinical outcomes of subacute two stage metatarsal lengthening with gradual distraction for brachymetatarsia. This technique was developed to overcome the disadvantages of one-stage metatarsal lengthening and gradual distraction. METHODS: Four feet of three patients with congenital brachymetatarsia underwent subacute two stage metatarsal lengthening with gradual distraction. Pain, function, and alignment were assessed preoperatively and at follow-ups using the American Orthopaedic Foot and Ankle Society (AOFAS) lesser metatarsophalangeal-interphalangeal scale, and any complications were recorded. RESULTS: The patients were followed up for a mean of 18.1 ± 6.9 (range, 12.6-28.1) months. The mean metatarsal length gain was 15.2 ± 3.2 (range, 12.1-18.5) mm, and the corresponding percent increase was 32.5 % ± 7.0 % (range, 25.7-41.1 %). The mean AOFAS score (0-100) was 97.5 ± 5.0 at the final follow-up. The external fixator index was 10.2 ± 1.5 (range, 8.1-11.6) days/cm. None of the patients experienced metatarsophalangeal stiffness, subluxation or dislocation of the metatarsophalangeal joint, loss of correction, pin tract infection, delayed union, nonunion, or angular deformities. CONCLUSION: Subacute two stage metatarsal lengthening with gradual distraction is a reliable alternative treatment for brachymetatarsia.

Braquimetatarsia: propuesta de tratamiento en base a técnicas de alargamiento: a propósito de dos casos / Brachymetatarsia: treatment proposal based on lengthening techniques: about two cases / Braquimetatarsia: proposta de tratamento baseada em técnicas de alongamento: sobre dois casos

Braquimetatarsia es el acortamiento anormal de uno o más metatarsianos. Tiene una incidencia de 0.02%-0.05% predominando en mujeres de 25 a 1. En un 72% puede ser bilateral. La etiología no es clara pero se plantea el cierre prematuro de la fisis dando un retardo en el crecimiento. La mayoría de las veces presenta síntomas causados por alteración en la mecánica de la parábola metatarsal como dolor e hiperqueratosis. Puede existir metatarsalgia y agregar en la evolución desviaciones digitales adicionales. El principal motivo de consulta es estético. El objetivo del reporte es mostrar dos técnicas quirúrgicas y los resultados clínicos correspondientes usando el score AOFAS, además de los resultados imágenológicos con hasta 5 años de seguimiento. Se describen dos pacientes y se analizan dos técnicas quirúrgicas diferentes para alargar los metatarsianos. Se trata de alargamientos agudos con interposición de injerto intercalar, en un caso mediante el procedimiento de Sandro Gianini con injerto de cresta ilíaca y en el otro con injerto de metatarsiano adyacente con modificación de la longitud del segundo y tercer metatarsiano restituyendo en ambos casos la parábola metatarsal. Obtuvimos buenos resultados al igual que series numerosas pudiendo recomendarse en casos similares.

Brachymetarsal is the abnormal shortening of one or more metatarsals. It has an incidence of 0.02%-0.05%, predominantly in women from 25 to 1. In 72% it can be bilateral. The etiology is not clear, but premature closure of the physis is suggested, giving growth retardation. Most of the time it presents symptoms caused by an alteration in the mechanics of the metatarsal parabola, such as pain and hyperkeratosis. There may be metatarsalgia and add additional digital deviations in the evolution. The main reason for consultation is aesthetic. The objective of the work is to show the surgical technique and the clinical results using the AOFAS score, in addition to the imaging results with up to 5 years of follow-up. Two patients are described and two different surgical techniques to lengthen the metatarsals are analyzed. These are acute lengthenings with intercalary graft interposition, in one case using the S.Gianini procedure with an iliac crest graft and in the other with an adjacent metatarsal graft with modification of the length of the second and third metatarsals, restoring in both cases the metatarsal parabola. We obtained good results. results as well as numerous series and can be recommended in similar cases.

Braquimetatarsal é o encurtamento anormal de um ou mais metatarsos. Tem incidência de 0,02%-0,05%, predominantemente em mulheres de 25 a 1 ano. Em 72% pode ser bilateral. A etiologia não é clara, mas sugere-se o fechamento prematuro da fise, causando retardo de crescimento. Na maioria das vezes apresenta sintomas decorrentes de uma alteração na mecânica da parábola metatarsal, como dor e hiperqueratose. Pode haver metatarsalgia e adicionar desvios digitais adicionais na evolução. O principal motivo da consulta é a estética. O objetivo do trabalho é mostrar a técnica cirúrgica e os resultados clínicos utilizando o escore AOFAS, além dos resultados de imagem com até 5 anos de seguimento. Materiais e métodos: São incluídos dois pacientes e analisadas duas técnicas cirúrgicas diferentes para alongar os metatarsos. São alongamentos agudos com interposição de enxerto intercalar, em um caso utilizando a técnica de S. Gianini com enxerto de crista ilíaca e no outro com enxerto de metatarso adjacente com modificação do comprimento do segundo e terceiro metatarsos, restaurando em ambos os casos o metatarso parábola. Obtivemos bons resultados, bem como inúmeras séries, podendo ser recomendados em casos semelhantes.

Longitudinal Epiphyseal Bracket of the First Metatarsal: A Case Series on Treatment of Deformities Associated.

Longitudinal epiphyseal bracket of the first metatarsal, also known as first enclosed metatarsal, is a rare congenital disorder characterized by an abnormal development in the length of the first metatarsal ray because of the asymmetric presence of a longitudinal epiphyseal bracket. This causes interruption in the lengthways development of the affected bone, which becomes squat and short, with a trapezoidal or triangular shape, leading to a hallux varus deformity. First enclosed metatarsal occurs in 2% to 14% of all congenital defects in the hands and feet; with bilateralism in 75% of cases and a greater incidence in male patients. The deformity is classified as a differentiation defect; it is frequently associated with abnormalities such as syndactyly or polydactyly. There are different surgical treatments reported in the literature. Most of them are aimed at the excision of the epiphyseal bracket before complete skeletal maturity and frequently in the first year of life to promote a normal lengthways growth of the bone. In this study, the authors present three cases of bilateral first enclosed metatarsal in which the surgical treatment, aimed at lengthening the first metatarsal ray by using the Penning Minifixator, was instead carried out at the end of growth. This different surgical approach allowed the planning of a surgical operation involving both the skeletal structures and the surrounding soft tissue.

Treatment of Cleft Foot Deformity using Fish Mouth Incision and Suture-Button in Paediatric Foot: A case report.

Cleft foot is a congenital anomaly characterised by absence of the metatarsal bones and phalanges. It is commonly seen in children with ectrodactyly-ectodermal dysplasia-clefting syndrome ranging from a median cleft up to the mid metatarsals to a deep cleft up to the tarsal bones. Surgical treatment in the form of cleft closure, excision of the rudimentary metatarsal bone and cross K-wire fixation of metatarsal bones have been tried for the management of such cases. We report a one-year-old child who presented to the paediatric orthopaedic clinic at a medical college in New Delhi, India, in 2018 with type III cleft foot with four metatarsals. The patient was treated with a suture-button system using three transverse tunnels in the second and third metatarsal bones in order to bring them closer together. A satisfactory outcome was achieved with normal fitting footwear.

Influence of the length of the first and second metatarsal bone measured distal from Maestro line upon severity of hallux valgus deformity.

To examine the influence of the configuration of the first and second metatarsal (MT) bones on the development of hallux valgus deformity. To determine the extent to which the difference in the lengths of the first and second MT bones, measured distal to the Maestro line, contribute to the severity of the hallux valgus (HV) deformity defined by the size of the hallux valgus angle (HVA) and inter-metatarsal angle (IMA). On a sample of 319 feet with HV deformity the difference of measured lengths R = d (I MT) - d (II MT) was calculated The influence of differences (R) on the values of IMA and HVA as well as on the severity of deformities according to the formed groups was investigated. The influence of age on the development of deformities was examined separately as well as in conjunction with the determined difference in lengths. In 203 feet or 63.7%, a shorter MT bone was measured, while in 80 feet or 25.1% the first MT bone was longer than second ones and only in 36 feet or 11.3% there is no difference in the length of the 1st and 2ndMT bones distal to the Maestro line. A statistically significant correlation was found between the difference between the measured lengths of 1st and 2nd MT bones and IMA, while this correlation with HVA was not statistically significant. There is no statistically significant correlation or the effect of the difference in measured lengths (R) on the severity of hallux valgus deformity classified into three groups. A statistically significant correlation and impact of the age on the intensity of the deformity are established. A shorter 1st MT bone in correlation to the 2nd MT bone is accompanied by an increase in IMA and this correlation and impact are statistically significant. It was not established that there was a statistically significant influence of the length of the first and second metatarsal bone measured distal from Maestro line upon the values of HVA and severity of HV deformity. Age significantly contributes to the severity of the deformity.

Demonstration With Three-Dimensional Volumetric Magnetic Resonance Sequences of Deep Peroneal Nerve Compression on Os Intermetatarseum Syndrome.

ABSTRACT: The os intermetatarseum is a rare accessory bone of the foot. It is commonly asymptomatic, as are other such accessory bones of the foot. Nevertheless, when it becomes symptomatic, it can cause "os intermetatarseum syndrome." Reported here is a case of os intermetatarseum syndrome, which is extremely rarely seen. To the best of the authors' knowledge, there are very few cases of os intermetatarseum syndrome in the literature.

Callus distraction with external fixator for the treatment of congenital brachymetatarsia of the fourth ray.

BACKGROUND: Brachymetatarsia is a rare abnormality of the foot which occurs most frequently in the first and fourth metatarsals. The aim of this study was to evaluate the efficacy of gradual metatarsal lengthening by external fixator for treatment of brachymetatarsia of the fourth ray. The hypothesis was that with external fixation it would be possible to achieve the desired length of the metatarsal with a low rate of complications. Secondarily, in cases requiring a greater amount of correction, it was hypothesized that an opportune rate of bone consolidation would be achievable using a traditional oscillating saw without predrilling or use of a cold osteotome. METHODS: Between 2013 and 2016, 12 eligible patients and 13 feet underwent gradual metatarsal lengthening by an external fixator (MiniRail System M103, Orthofix) due to brachymetatarsia of the fourth ray. Mean age at surgery was 24.5±5.3 years (range 19-36), with mean follow-up of 22.3±8.3 months. Clinical evaluation was performed with the AOFAS lesser metatarsophalangeal-interphalangeal (MTP-IP) score. Radiographic assessment was performed on follow-up using non-weightbearing dorsoplantar foot radiographs. RESULTS: The mean AOFAS lesser MTP-IP score improved from a preoperative score of 76.6±7.1 points (range 62-85 points) to a postoperative score of 90.3±3.0 points (range 86-95 points). The average amount of lengthening was 16.8±3.9mm (range 8-22mm). Mean shortening, final lengthening, Healing Index, period of treatment, and complications are also reported. The operative technique is described. CONCLUSIONS: Gradual metatarsal lengthening with external fixator is an effective treatment for brachymetatarsia and can restore forefoot anatomy with good clinical outcomes, a low rate of morbidity and complications in selected cases. Particular attention should be given when treating patients with shortening >20mm.

Disproportion and dysmorphism in an adult Belgian population with Turner syndrome: risk factors for chronic diseases?

BACKGROUND: Turner syndrome (TS) is characterized by dysmorphism and body disproportion. TS women are also susceptible to a range of chronic disorders including arterial hypertension (AHT), osteoporosis, sensorineural hearing loss (SNHL), type 2 diabetes mellitus (DM2) and thyroid disease. The association between dysmorphism/body disproportion and chronic disease has never been studied in TS women. The effect of growth hormone treatment on body disproportion is also unclear. Objectives: to analyze dysmorphic features and body disproportion in TS women in relation to the presence of chronic disease and to document the effect of growth hormone therapy on body disproportion. METHOD: 76 adult TS women with a regular follow up at the TS clinic UZ Ghent were invited to participate. Detailed body measurements were performed in 44 volunteering TS women. Scoring systems for overall dysmorphism, craniofacial dysmorphism, thoracic and limb abnormalities and skeletal disproportion were developed. RESULTS: TS women with a higher dysmorphism score were more at risk for AHT (p = 0.04) as well as those with a higher sitting height/standing height ratio (p < 0.05). Prevalence of AHT, osteoporosis and DM 2 was lower in TS women treated with GH during childhood (p < 0.05). CONCLUSIONS: Adult TS women with relatively short legs or with more physical dysmorphic stigmata were more at risk for AHT. GH therapy does not seem to increase the risk of chronic disease on the long term.

Forefoot malformations, deformities and other congenital defects in children.

Congenital pathologies of the forefoot encompass two broad entities with vastly different treatments and prognosis: malformations, which occur during the embryonic period and cause anatomical defects, and deformations, which occur during the fetal period on a foot that is configured normally. These deformities are more easily cured when they occur later during the fetal period. When the anomaly is bilateral, a genetic origin must be considered. There are two main entities under the term "deformity": metatarsus adductus and skewfoot (aka "Z"-foot or serpentine foot). Within malformations are brachydactyly (transverse defects), longitudinal defects, syndactyly, polydactyly, clinodactyly and macrodactyly. Among other forefoot abnormalities are hallux valgus, which rarely presents in congenital form, and for which conservative treatment is sometimes sufficient. Also in this group are sequelae of amniotic band constriction, forefoot anomalies secondary to the treatment of congenital pathologies (talipes equinovarus and congenital vertical talus) and nail-related pathologies (ingrown toe nail and incorrect nail position).

Isolated hexadactylia: A rare case of central polydactyly of the foot.

BACKGROUND: Central polydactyly of foot is uncommon form of polydactyly but it usually causes intermetatarsal widening because of metatarsal bifurcation. Central polydactyly associated with T shaped bifurcation of metatarsal in vertical plane has not been reported yet. CASE: We present a 4 year male child with extra toe on the dorsal aspect of right foot with complains of difficulty in wearing footwear and poor cosmesis. The extra digit was fully developed with bifurcation of 2nd metatarsal bone proximal to the head without any intermetatarsal widening. The angular deviation was 45° to the longitudinal axis of foot and in a plane vertical to the transverse arch of foot. The child was operated with excision of extra toe without any residual bony deformity. CONCLUSION: The central polydactyly is rare type of polydactyly of foot. Central polydactyly with metatarsal extension causing intermetatarsal widening has been well described entity. But the previous classifications need to be modified to include central polydactyly with vertical oriented T bifurcation of metatarsal bone without intermetatarsal widening.

Does Hallux Valgus Exhibit a Deformity Inherent to the First Metatarsal Bone?

Hallux valgus is a common condition, and it still poses some challenges. The identification of factors associated with the development of the deformity is of paramount importance in obtaining a full correction of the disorder. Hallux pronation is one of the frequently found components, especially in larger deformities, but the cause and exact location of this condition are not fully understood. The aim of the present study was to investigate whether there is a rotational deformity inherent to the first metatarsal bone. A case-control study was conducted on patients with and without hallux valgus who were subjected to computed tomography with multiplanar reconstruction. Statistical analysis was performed by means of a mixed model adjusted for foot and gender to compare metatarsal rotation between cases and controls. Correlations between numerical quantitative measurements were investigated by means of Pearson's correlation coefficient obtained in a linear mixed model. A total of 82 feet (tests) were analyzed in the hallux valgus group and 64 feet (tests) in the control group (N = 146). The hallux valgus group was significantly different from the control group (p< .001). Mean metatarsal bone rotation was 15.36° (range 1.65° to 32.52°) in the hallux valgus group and 3.45° (range -7.40° to 15.56°) in the control group. The difference between the means was 11.9° (confidence interval 9.2° to 14.6°). In conclusion, patients with hallux valgus exhibited increased exclusive bone rotation of the first metatarsal toward pronation compared with the population without this condition.

BET 1: Functional treatment is non-inferior to below the knee cast in adults with acute closed proximal fifth metatarsal fractures.

A short cut review was carried out to establish whether functional treatment is better than conservative treatment with a below knee cast at decreasing time to functional recovery and fracture union in adults with an acute closed proximal fifth metatarsal fracture. Four papers presented the best evidence to answer the clinical question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of these papers are tabulated. It is concluded that in proximal (zone 1 and 2) fractures of the fifth metatarsal functional treatment with immediate mobilisation is at least non-inferior to immobilisation in a cast.

Reproducibility of radiographic methods for assessing longitudinal tarsal axes: Part 1: Consecutive case study.

INTRODUCTION: Calcaneal pitch angle and Meary's angle are commonly used to assess longitudinal foot arches on lateral-view radiographs. However, the methods used to obtain the talar, first metatarsal, calcaneal, and plantar axes differ across multiple reports, and no study has evaluated the reproducibility of these approaches. The aim of this study was to determine the most reproducible methods for radiographically evaluating longitudinal axes. METHODS: Standing radiographic images of 40 feet from 21 consecutive outpatients were obtained to measure longitudinal axes of the talus, first metatarsal, calcaneus and plantar surface, which were defined using six, five, four and three different methods, respectively, selected from previous reports. Intraobserver and interobserver correlation coefficients were calculated. RESULTS: The best intraobserver and interobserver correlation coefficients for the talar, first metatarsal, and calcaneal axes were obtained using methods involving a line bisecting the angle formed by the lines tangential to the superior and inferior margins of the talus, a line connecting the centre of the first metatarsal head and the midpoint of the visualized base of the first metatarsal, and a line drawn tangential to the inferior surface of the calcaneus, respectively. For the plantar axis, a method that used the horizontal plane (as a reference axis) was regarded as the best approach, although intraobserver and interobserver correlation coefficients could not be calculated because all values were zero. CONCLUSIONS: The aforementioned methods were considered to be optimal for the radiographic assessment of longitudinal foot arches. This study could contribute to more accurate assessments of foot deformities.

Nonsyndromic Massive Tarsal and Tarsometatarsal Coalitions in a Young Female.

Tarsal coalition is an abnormal connection between 2 or more tarsal bones, with the most common sites being between the talus and the calcaneus and between the navicular and the calcaneus. The occurrence of multiple and massive tarsal coalitions is rare. We describe a rare case of nonsyndromic bilateral tarsal coalition involving most of the tarsal bones and extending to the metatarsal bones in a 4-year-old female. The condition was not painful and did not affect her gait. The main concern was the abnormal shape of her feet. Tarsal coalition can occur as an isolated anomaly or in association with other congenital disorders, usually presenting around the age of 12 years. The coexistence of nonsyndromic bilateral multiple tarsal coalitions is seldom reported. Regardless of the presentation, treatment is not indicated in cases of asymptomatic tarsal coalition. Our patient had a unique presentation of tarsal coalition, involving both the tarsal and tarsometatarsal bones. To our knowledge, this is the first report of this type of presentation.