Biphalangeal fifth toe: an increasingly common variant?

Focused Extracorporeal Shock Wave Therapy for Painful Delayed Union or Nonunion of Fractures of Interphalangeal Coalition

Background

Interphalangeal coalition is characterized by fusion of interphalangeal joint between the middle and distal phalanges. Interphalangeal coalition fractures often result in delayed union or nonunion. The purpose of this study was to evaluate the results of focused extracorporeal shock wave therapy (ESWT) for painful delayed union or nonunion of fractures of the interphalangeal coalition.

Methods

The study group consisted of 9 patients (9 feet) diagnosed with painful delayed union or nonunion due to persistent pain and no tendency toward bony union for at least 3 months after the interphalangeal coalition fracture on plain radiographs between 2021 and 2023 were included. The mean age was 51.3 years (23-64). Focused ESWT was performed in all patients. The mean time from the date of injury to the start of ESWT was 16.1 weeks (12-15). ESWT was performed every 2 weeks, with each session consisting of 3000 impulses (0.15-0.25 mJ/mm2). Plain radiographs were used to confirm bone union, and visual analog scale (VAS) scores were used for pain assessment.

Results

Complete bony union was documented in all 9 patients. The application of focused ESWT was performed a mean of 2.7 times (2-4), and the mean duration from the initiation of treatment to the confirmation of bony union was 7.4 weeks (3.6-12.7). In all cases, the symptoms of swelling and pain were alleviated. The VAS scores exhibited significant improvement, with the mean VAS score decreasing from 3.8 (2-6) before ESWT to 0 after the achievement of union (P < .001).

Conclusion

In this small cohort, all patients with painful delayed union or nonunion of fractures at the interphalangeal coalitions achieved complete bony fusion after focused ESWT. Moreover, bony union was observed within 2 months of ESWT initiation. These findings suggest that focused ESWT may be a valuable treatment option for painful delayed union or nonunion of interphalangeal coalition fractures.

Level of Evidence

Level IV, case series.

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.

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.

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.

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.

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.

Characterization of a stapes ankylosis family with a NOG mutation

OBJECTIVE

To characterize the otologic phenotype in a family with autosomal dominant stapes ankylosis, hyperopia, and skeletal abnormalities caused by a mutation in the noggin gene (NOG).

STUDY DESIGN

Case series.

SETTING

Academic tertiary care center.

PATIENTS

Eight affected and 3 unaffected family members.

MAIN OUTCOME MEASURES

History, physical and radiologic examination, and surgical outcomes.

RESULTS

Although affected members were initially presumed to have typical nonsyndromic otosclerosis, the clinical data were most consistent with an autosomal dominant congenital stapes ankylosis syndrome. Eight of eight affected family members had bilateral low-frequency conductive hearing loss. Six of eight underwent fenestration procedures and/or stapedectomies. All members with initial postoperative closure of the air-bone gap returned to their baseline conductive loss within 2 years. Two affected family members had documented maximal conductive hearing loss by age 4, and two members without previous otologic surgery have not experienced sensorineural hearing loss. High-resolution temporal bone computed tomography showed stapes ankylosis and indistinction of the incudomalleal junction bilaterally and bony regrowth over the stapedotomy for those with stapedectomies. Detailed physical and radiologic examination identified multiple other skeletal abnormalities.

CONCLUSIONS

Although this phenotype may present as classic otosclerosis to the otolaryngologist, detailed investigation revealed a congenital stapes ankylosis syndrome. Because is essential in regulating normal bone development and maturation, mutations in this gene may be associated with excessive bony overgrowth and refixation of the stapes footplate after initial successful surgery. Patients with hereditary conductive hearing loss should be assessed to rule out subtle features of a skeletal syndrome.