Symphalangism (two phalanges) in the digits of the Japanese foot

Previously unreported X-ray findings associated with distal toe pain in children

While children undergo skeletal maturation, it is difficult to distinguish between normal variants and abnormalities of the epiphysis and acrophysis on radiological images. Abnormalities in the epiphysis and acrophysis of the toe phalanx have not been reported yet. Here, we describe a series of abnormalities in the epiphysis and acrophysis of the fourth and fifth toe phalanges, including an investigation of their pathogenesis. We evaluated patients suspected of having bone tumors at a local orthopedic clinic because of abnormal findings of the toe phalanx between the distal and middle phalanx on plain radiographs. The site of the lesion, duration of pain until the hospital visit, history of trauma and sports, treatment, and clinical course were investigated. A total of seven patients (five boys and two girls) with a mean age of 10 years (range 9-16) were included. In all cases, a circular erosive radiolucent image was present between the distal and middle phalanx. In two cases, the fourth toe was affected, and in five cases, the fifth toe was affected. Six patients showed improvements with conservative treatment using shoe insoles. In one case, surgical treatment was performed for persistent pain. Histological examination of the fibrous tissue collected from the circular erosive radiolucent area revealed normal bone and slightly degenerated hyaline cartilage. This is the first report on the abnormalities of the epiphysis and acrophysis of the toe phalanx, which is termed as Shintaniwakino disease. A better understanding of this disease may aid in the avoidance of unnecessary treatment.

The Prevalence of Accessory Ossicles, Sesamoid Bones, and Biphalangism of the Foot and Ankle: A Radiographic Study

Background:

Accessory ossicles, sesamoid bones, and biphalangism of toes are the most common developmental variations of the foot. These bones may be associated with painful syndromes; however, their clinical importance is not well understood because the reported prevalence varies widely. Therefore, we aimed to investigate these variants in Turkish subjects.

Methods:

A total of 1651 foot radiographs were retrospectively assessed. Radiographs of feet were examined regarding the prevalence, sex, and bilaterality of accessory ossicles, sesamoid bones, and biphalangism in Turkish subjects.

Results:

Accessory ossicles (26.1%) and sesamoid bones (8%) were detected. The most common accessory ossicles were os trigonum (9.8%), accessory navicular bone (7.9%), and os peroneum (5.8%). Also, we detected os supratalare (0.48%), os calcanei secundarium (0.42%) os subfibulare (0.42%), os supranaviculare (0.36%), os vesalianum (0.30%), os subtibiale (0.24%), os intermetatarseum (0.12%), and os subcalcis (0.12%). We observed bipartite hallux sesamoid in 1.8% and interphalangeal sesamoid bone of the hallux in 0.7% of radiographs. Incidences of metatarsophalangeal sesamoid bones were found as 0.6%, 0.06%, 0.6%, and 5.8% in the second, third, fourth, and fifth digit, respectively. We observed biphalangeal toe in 0.5%, 1.7%, 3.5%, and 37.6% in the second, third, fourth, and fifth toe, respectively.

Conclusion:

This study is the first detailed report on the incidence of the most common variants of the foot and ankle in a wide-ranging patients’ series in Turkish subjects. Our study’s findings will contribute to reducing misdiagnosis.

Clinical Relevance:

The results of this study may provide anatomical data that could help clinicians in the diagnosis and management of disorders that present with pain and discomfort in the feet. Knowledge of these variants is important to prevent misinterpreting them as fractures.

Phenotypic heterogeneity in individuals with MECOM variants in 2 families

MECOM encodes the transcriptional regulators, EVI1 and MDS1-EVI1, from two distinct transcription start sites. EVI1 plays important roles in hematopoiesis and stem cell self-renewal. Recently, our group and others revealed that individuals with MECOM variants present diverse hematological and skeletal defects, including radioulnar synostosis (RUS). In the present study, we analyzed two families suspected with MECOM-associated syndrome. In family 1, a MECOM splicing variant (c.2285+1G>A) was identified in an individual with bone marrow failure (TRS4) without RUS and her mother, who had mild leukocytopenia, thrombocytopenia, and bilateral RUS. A copy neutral loss of heterozygosity decreasing the variant allele frequency was observed in the bone marrow of TRS4 and the peripheral blood leukocytes of her mother. However, TRS4 remained transfusion-dependent. In family 2, a MECOM variant (c.2208-4A>G), which was predicted to cause a cryptic acceptor site that results in a 3-base insertion (an insertion of Ser) in the mRNA, was identified in the proband, with bone marrow failure; this variant was also observed in her brother and father, both of whom have skeletal malformations, but no cytopenia. RT-PCR using leukocytes revealed a transcript with a 3-bp insertion in the proband, her brother, and the father, suggesting that the transcript variant with a 3-bp insertion is independent of blood phenotype. Collectively, these results suggest the presence of intrafamilial clinical heterogeneity in both families with MECOM splicing variants. Somatic genetic event may complicate the understanding of clinical variability among family members.

Prevalence of Accessory Bones and Tarsal Coalitions Based on Radiographic Findings in a Healthy, Asymptomatic Population

Background

Accessory bones and tarsal coalitions are the most common developmental variations of the foot and ankle. However, their clinical implications are not well understood because there is no established prevalence data in the normal population and the reported prevalence varies widely. Therefore, we aimed to investigate the incidence of accessory ossicles and tarsal coalitions in a healthy, asymptomatic Korean population.

Methods

A total of 448 healthy, asymptomatic participants (224 men and 224 women; 896 feet) were enrolled and stratified by age and sex. To investigate the presence of accessory bones and tarsal coalitions in the foot and ankle, we obtained the weight-bearing standing radiographs (anteroposterior and lateral views) from each participant.

Results

Accessory ossicles were found in 49.2% of the healthy, asymptomatic Korean adults. The prevalence of accessory bones in adults was the highest with 34% for the accessory navicular, 5.8% for the os trigonum, 3.9% for the os peroneum, and 1.7% for the os subfibulare. The prevalence of tarsal coalitions in adults was 0.4% and that of symphalangism was 16% for the fourth toe and 80.6% for the fifth toe. The frequency of the accessory navicular and fifth toe symphalangism was significantly higher in women. Most of the accessory navicular and fourth and fifth toe symphalangism were bilateral, whereas the os subfibulare was mostly unilateral.

Conclusions

The prevalence of accessory bones and tarsal coalitions in the healthy, asymptomatic Korean population showed some variation according to age and sex.

The incidence of biphalangeal fifth toe: Comparison of normal population and patients with foot deformity

BACKGROUND

Pedal biphalangism, which was also defined as symphalangism, is seen at a frequency that cannot be ignored; however, no study can be found in the literature evaluating biphalangism in normal population in comparison to those who have foot disorders. The aim of this study was to evaluate the incidence of the pedal fifth toe symphalangism in normal population and in patients with foot deformity including hallux valgus, pes planus, pes cavus, and pes equinovarus. We hypothesized that pedal fifth toe symphalangism may be a predisposing factor or an accompanying structural variation for foot deformity.

MATERIALS

Patients admitted to the emergency department of our center in October and November 2016 were defined as the control group, and patients with the diagnosis of hallux valgus, pes planus, pes cavus, and pes equinovarus treated between 2011 and 2016 in our department were defined as the foot deformity group. Individuals who had anteroposterior, oblique, and lateral radiographs of foot were included in the study.

RESULTS

One thousand and four patients participated in the cross-sectional observational study. Biphalangeal fifth toe was found in 328 of 1004 (32.7%) patients. In foot deformity group ( n = 672), 222 patients (33%) had biphalangeal fifth toe. In the control group, 106 (31.9%) of the 332 patients had biphalangeal fifth toe. There was no statistically significant difference in the incidence of biphalangeal fifth toe between the two groups ( p = 0.72).

CONCLUSIONS

According to the results of this study, biphalangeal fifth toe is a common pedal anatomical variant seen approximately in one-third of the population who have either foot deformity or not. This information may be valuable for podiatrist undertaking the conservative or surgical treatment of fifth toe-related disorders.

Novel NOG (p.P42S) mutation causes proximal symphalangism in a four-generation Chinese family

Background

Proximal symphalangism (SYM1; OMIM 185800), also called Cushing’s symphalangism, is an infrequent autosomal dominant disease. An SYM1 patient typically features variable fusion of proximal interphalangeal joints in the hands and feet.

Methods

We recruited a four-generation Chinese non-consanguineous family with SYM1. We examined their hands and feet using X-rays to confirm fusion of proximal interphalangeal joints. We evaluated their audiology using standard audiometric procedures and equipment. Then, we identified genetic variants using whole exome sequencing and validated mutations using Sanger sequencing. Mutation pathogenicity was analyzed with bioinformatics.

Results

Radiographs revealed proximal-joint fusion of fingers and toes in the patients. Two elderly individuals (II:1 and II:4) exhibited slight hearing loss. Additionally, we detected a novel heterozygous missense mutation in exon 1 of NOG (NM_005450) c.124C > T, p.(Pro42Ser) in all patients. This c.124C > T mutation is highly conserved across multiple species and the p.(Pro42Ser) variation is potentially highly pathogenic.

Conclusion

Our results suggest that heterozygous c.124C > T, p.(Pro42Ser) in NOG is a novel mutation that causes human SYM1 phenotype.

Electronic supplementary material

The online version of this article (10.1186/s12881-019-0864-1) contains supplementary material, which is available to authorized users.

Prevalence of toe symphalangism in Hong Kong Chinese population

Objective:

To explore the prevalence and variations of toe symphalangism in the Hong Kong Chinese population.

Methods:

A retrospective review of foot radiographs taken in Chinese adult patients admitted to United Christian Hospital from 1 January, 2016 to 31 December, 2016. Exclusion criteria include (1) previous toe amputation, (2) skeletal immaturity, (3) severe deformity, and (4) repeated attendance. The frequencies were compared by χ 2 test.

Result:

A total of 1364 foot radiographs were reviewed. Six-hundred sixty radiographs were excluded. A total of 704 radiographs were included in this study. There were total 849 feet reviewed (left: 290, right: 269, bilateral: 145). Their mean age (± standard deviation) was 59.5 ± 14.2 years. The prevalence of 2nd, 3rd, 4th, and 5th toe symphalangism was 0.2%, 0.8%, 9.9%, and 76.7%, respectively. The prevalence resembles Asian population. There was no significant difference in the prevalence associated with the following factors: (1) gender and (2) left versus right foot. There was no 4th toe symphalangism without 5th toe involvement. In the 145 bilateral feet radiographs, asymmetrical distribution of toe symphalangism was found in 8.2%. Second toe symphalangism is rare (0.24%).

Conclusion:

This is the first study in Hong Kong to report prevalence of toe symphalangism in Chinese population. There is a high prevalence rate of 5th toe symphalangism in the Hong Kong Chinese Population. This implies less flexible lesser toes in the Chinese population with higher risks of development of deformities. The clinical implication of such findings needs further research.

The prevalence and ossification pattern of the biphalangeal and triphalangeal lateral toes

Purpose

Biphalangealism of the toes is an exclusively human phenomenon. The aim of this study was to evaluate the development of the lateral toes in childhood by following the ossification pattern of the phalanges.

Methods

Foot radiographs of 913 adults have been evaluated for biphalangealism of 3rd to 5th toe. The pediatric group, aged 6–15 years of age, was assessed for the number of ossification centers in the foot.

Results

In adults, the mean prevalence of biphalangealism in the 5th toe was 41.39%, in the 4th toe was 2.15%, and in the 3rd toe was 0.48%. In children, 45% feet had four ossification centers in the 5th toe. The epiphysis center of the middle and distal phalanx was missing. In the 4th toe, four centers were present in of 2.47% of cases. Those values are similar to the prevalence of the biphalangeal toes in adult population. The remaining toes had 5 or 6 ossification centers. In the 5-center toe, the epiphysis of the middle phalanx was missing.

Conclusion

A missing distal phalanx epiphyseal ossification center is considered indicative of a biphalangeal toe, and the toes with 5 or 6 ossification centers are indicative of triphalangeal toes. The reason for such evolution of the lateral toes is still debated, but the differences in anatomy most likely have no impact on foot function.

Ergonomic footwear for Sri Lankan primary schoolchildren: A review of the literature

BACKGROUND

Foot ailments are common among schoolchildren, some of which may be attributed to wearing ill-fitting footwear. As schoolchildren often participate in athletic activity, they are doubly vulnerable to foot ailments, and are particularly vulnerable to conditions such as hallux valgus, Achilles tendonitis, athlete's foot, corns and calluses. Thus, there is an acute need for the design and manufacture of ergonomic footwear for this target group. While research on appropriate footwear for children has been carried out in relation to child populations in other societies, research on the circumstances of Sri Lankan schoolchildren is lacking. Neither the requisite design know-how nor the information for design is available to footwear manufacturers.

OBJECTIVES

This review of the literature is aimed at confirming the need for ergonomic footwear from the point of view of the effects of wearing ill-fitting shoes and at identifying the requirements in terms of design information, especially for schoolchildren of the age group five to ten years, to empower footwear manufacturers.

METHODS

PubMed, Google scholar and Science Direct were used for the literature search.

RESULTS

208 publications were read in full, 94 of which are referenced in this review.

CONCLUSION

The review shows morphological measurements, behavior and activity patterns of schoolchildren and environmental conditions they are exposed to should be determined to formulate design information.

Non-metric variation of the middle phalanges of the human toes (II-V): long/short types and their evolutionary significance

The human lateral toes are characterised by extreme reduction compared with other primates, and in particular other hominoids. Some phalangeal non-metric variants have been well identified in humans, in particular: triphalangeal/biphalangeal patterns, and the presence/absence of phalangeal secondary centres of ossification. The purpose of the present study was to describe and analyse an original non-metric variation of the middle phalanges of the lateral toes. The material consisted of 2541 foot radiographs that came from 2541 different European adult individuals. Two morphological types of the middle phalanx were defined as a simple binary trait: long type (L) and short type (S). In feet with a triphalangeal pattern in all lateral toes (1413 cases), a mediolateral increasing gradient was observed in the occurrence of type S: 8.1% in II; 30.7% in III; 68.4% in IV; and 99.1% in V. In feet with a biphalangeal pattern in one or more lateral toes (III-V; 1128 cases), type S occurred more frequently than in triphalangeal feet. Of the 30 theoretical arrangements of the L/S types in the lateral toes (II-V) in a complete foot, only 13 patterns were observed. Seven patterns represented 95.6% of the population: LLSS (20.9%), LLLS (17.1%), LSS (15.9%), SSS (14.5%), LSSS (12.7%), LLS (10.1%) and SSSS (4.4%). Type L can be interpreted as the primitive pattern (plesiomorphy), and type S as a derived pattern (apomorphy) that seems specific to the human species (i.e. autapomorphy). Within the specific evolution of the human foot in relation to the acquisition of constant erect posture and bipedalism, the short type of the middle phalanges can reasonably be considered as directly linked to the reduction of the lateral toes.

Biphalangeal/triphalangeal fifth toe and impact in the pathology of the fifth ray

Background

Having reviewed the studies on the biphalangeal fifth toe, we have observed a great disparity of data depending on the research center. We have investigated the frequency of biphalangeal toes and also its handedness. We have also analyzed the relationship of pathological deviations of fifth toe with this feature and with the fifth metatarsal.

Methods

We performed a descriptive prospective study, which analyzed 2494 feet (1247 people) with bilateral dorsoplantar radiographs. We studied the number of phalanges of the fifth toe, the deviations in the sagittal and transverse plane, and the state of the fifth metatarsal phalangeal joint.

Results

After analyzing the data we found the presence of biphalangeal fifth toe in 46.3% of the feet, presenting this feature bilaterally in 97.4% of them. A statistically significant higher percentage of pathological toes was found in people with triphalangeal fifth toe (pathological in 29.91%) than in the biphalangeal toes (pathological in 15.60%). We found that these differences are accentuated in the alterations of the fifth toe in the sagittal plane.

Conclusions

It is almost 4 times more likely to suffer a fifth hammer toe if the fifth toe is triphalangeal (OR = 3.98 to p =0.000). Alterations in the coronal plane of the fifth toe are associated with tailor’s bunion (p =0.000). We did not find any significant differences regarding the need for surgery of the fifth toe of the biphalangeal (39.1%) versus triphalangeal toes (60.9%). Clinical relevance: There may be an association between pathologic deviations and bigger mobility of the triphalangeal fifth toes. However, biphalangeal fifth toes show bigger rigidity leading to smaller accommodation inside the shoe, which may lead to less painful feet and decreased proportion of surgery.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-295) contains supplementary material, which is available to authorized users.

Giant cell tumor of the distal phalanx of the biphalangeal fifth toe: a case report and review of the literature

Giant cell tumor of the distal phalanx of a toe is rather unusual. We report an unusual case of giant cell tumor arising at the distal phalanx of the left biphalangeal fifth toe in a 13-year-old boy. This was treated successfully with curettage and packing with bone substitution.

Biphalangeal fifth toe

BACKGROUND

A biphalangeal fifth toe is a common variant in the European population. The frequency is higher in the Japanese population. It is considered an anatomical variant of the normal triphalangeal fifth toe.

METHODS

Patients divided into three study groups were retrospectively reviewed to determine the effect of a biphalangeal fifth toe on the occurrence of clinically symptomatic pathology of the fifth ray.

RESULTS

The prevalence of a biphalangeal fifth toe in patients with hammer or claw toes was 65%, bunionettes 47%, and overriding fifth toe 37%. Only for the group with hammer or claw toes was prevalence significantly higher than that in the control group (39%).

CONCLUSION

The stiffness and rigidity of the biphalangeal fifth toe may predispose it for symptomatic hammer or claw toe.

Secondary centers of ossification of the human toes: exceptional polymorphism and evolutionary perspectives

As great morphological variability characterizes the phalanges of the human toes in adults, we hypothesized for a possible variability in the presence or absence of their secondary (= epiphyseal) centers of ossification linked to the unique morphology of the human foot within primates. The aim of this study was thus to provide original and detailed data on the occurrence of these centers. Classically, the big toe or hallux (I) presents two secondary centers and the lateral toes (II-V) three centers, and consequently the five toes present a total of 14 secondary centers. The material studied consisted of 261 foot radiographs from 261 young individuals of European origin (202 males and 59 females; 6-16 years). The presence (or absence) of the secondary centers of the phalanges of the toes was assessed for each foot. Feet presenting a biphalangeal variant in one or more lateral toes were studied separately. The theoretical possibilities of association of the three secondary centers in a given lateral toe (II-V) are eight in number; these eight patterns were studied and coded in the present study by types A-H. An exceptional variability in the occurrence of the secondary centers in lateral toes (II-V) was observed, and the classic pattern of phalangeal ossification was never observed. The absence of one or more secondary centers seems to be observed only in the human species, and we suggest that this could be a derived pattern specific to the human species, i.e., autapomorphic pattern. These results are of interest in the characterization and understanding of the reduction in size of the lateral toes which characterizes the specific evolution of the human foot.

Pedal symphalangism in modern American and Japanese skeletons

Pedal symphalangism is a surprisingly common heritable trait of the human foot. In individuals exhibiting the trait, the joint between the intermediate and distal phalanges of one or more lateral toes never develops, resulting in toes with two phalanges rather than three. This study was undertaken to explore variation in the frequency of pedal symphalangism among groups with widely different geographic ancestry, and to consider the applicability of this trait to skeletal biological distance studies. A total of 460 Euro-American, 191 African-American and 99 Japanese skeletons were examined for presence of pedal symphalangism. The American individuals date to the first half of the 20th c, while the Japanese individuals date to the late 19th and early 20th c. Although the country of ancestry is unknown for most of the American individuals, the Euro-Americans appear to be largely northern European, with roots in Germany, Ireland and Scandinavia, while the African-Americans are primarily descendants of slaves with roots in west African countries such as Nigeria, Benin, Togo, Ghana and Sierra Leone. Frequencies of fifth toe pedal symphalangism were calculated and compared among all three samples and found to be significantly higher in modern Japanese (83.7%) than in either Euro-Americans (46.4%) or African-Americans (44.0%). The Euro- and African-American frequencies were statistically indistinguishable for symphalangism of the fifth toe. In the fourth toe, however, the opposite result was found. The African-American frequency (7.9%) was significantly higher than the Euro-American frequency (2.6%), while no difference was found between the African-Americans and Japanese (11.7%). Since fourth toe pedal symphalangism has never been observed in the absence of fifth toe involvement, some of the same genes are clearly involved in producing the trait in both toes. However, differences in the pattern of fourth and fifth toe expression among the three groups identified in this study suggest that additional genetic or developmental factors may play a role in expression of pedal symphalangism in each of the toes.