Brachymetatarsia: congenitally short third and fourth metatarsals treated by distraction lengthening--a case report and literature summary

The Use of Fluorescence In situ Hybridisation in the Diagnosis of Hidden Mosaicism in Egyptian Patients with Turner Syndrome

Background

Turner syndrome (TS) is the most common chromosomal abnormality in females. The diagnosis of TS is based on karyotyping of 30 blood lymphocytes. This technique does not rule out tissue mosaicism or low-grade mosaicism in the blood. Because of the associated risk of gonadoblastoma, mosaicism is especially important in case this involves a Y chromosome.

Aims

This study was set to determine the value of additional genetic studies such as fluorescent in situ hybridisation and the inclusion of buccal cells in search for mosaicism in TS patients.

Settings and Design

This cross-sectional, descriptive study was performed in Human Genetics Department, Medical Research Institute, Alexandria University.

Materials and Methods

Fluorescence in situ hybridisation technique was applied to lymphocyte cultures as well as buccal smears using centromeric probes for X and Y chromosomes. Genotype phenotype correlation was also evaluated.

Statistical Analysis Used

Descriptive study where categorical variables were described using number and percentage and continuous variables were described using mean and standard deviation.

Results

Fluorescence in situ hybridisation technique study detected hidden mosaicism in 60% of studied patients; 20% of patients had a cell line containing Y material, while 40% had variable degrees of X, XX mosaicism, and in the remaining 40% no second cell line was detected. Fluorescence in situ hybridisation study helped identify the origin of the marker to be Y in all patients. The introduction of an additional cell line helped in identifying mosaicism in patients with monosomy X. Virilisation signs were only observed among TS patients with Y cell line mosaicism. The clinical manifestations were more severe in patients with monosomy X than other mosaic cases.

Conclusions

Molecular cytogenetic investigation for all suspected cases of TS should be considered for appropriate treatment plan and genetic counselling.

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.

Metatarsal Gradual Lengthening for Brachymetatarsia Using a Mini-rail External Fixator System

Aim

To describe the surgical technique for gradual lengthening of the metatarsal using the Orthofix MiniRail System (Orthofix Medical Inc., Lewisville, TX, USA).

Background

Brachymetatarsia refers to the shortening of the metatarsal bone. When indicated, metatarsal lengthening is performed to treat this deformity.

Technique

A dorsal approach to the short metatarsal is performed, protecting the neurovascular structures and the extensor tendons. The most proximal wire or screw is inserted first, followed by the most distal wire or screw. The distal wire or screw should not be inserted in the metatarsal head. The middle wires or screws are inserted thereafter. All wires or screws should be placed perpendicular to the anatomic axis of the bone. Once the MiniRail lengthener is assembled, a 1.6 mm K-wire is inserted from the tip of the toe into the metatarsal head, blocking the motion of the metatarsophalangeal joint and avoiding joint subluxation during lengthening. The osteotomy is then performed perpendicular to the metatarsal shaft, in between the middle two wires and screws.

Conclusion

The surgical technique for gradual lengthening of the metatarsal using the Orthofix MiniRail System was described in detail with accompanying step-by-step intraoperative clinical and fluoroscopic images.

Clinical significance

This surgical technique of metatarsal lengthening is simple and effective. An understanding of the surgical technique of gradual lengthening of the metatarsal bone is important when treating shorting deformities of more than 1 cm.

How to cite this article

Marwan Y, Abu Dalu K, Bernstein M, et al. Metatarsal Gradual Lengthening for Brachymetatarsia Using a Mini-rail External Fixator System. Strategies Trauma Limb Reconstr 2022;17(3):184-188.

The Surgical Treatment of Brachymetatarsia

This article describes the 3 main surgical options for correction of congenital brachymetatarsia in childhood. The one-stage lengthening by lengthening osteotomy and lengthening with graft interposition are suitable for defects less than 10 mm. For the greater defects from 10 mm to more than 20 mm, gradual lengthening by callus distraction with an external or internal fixator is appropriate. Over the last years, callus distraction with an internal minifixator became commonly established because of the significantly improved aftercare with early full weight-bearing and high postoperative comfort for the child. All 3 surgical procedures are presented with comprehensive image material.

Hallux Valgus With Second Brachymetatarsia Discovered Accidentally: A Case Report

Hallux valgus deformity is one of the most common foot and ankle diseases, while brachymetatarsia is a rare foot anomaly with pathological shortening of a metatarsal bone. We present a case of hallux valgus deformity possibly due to second brachymetatarsia. As the hallux valgus was associated with dorsal dislocation of the second toe that made it difficult to evaluate the length of the second toe, the patient was unaware of the second metatarsal shortening until the lengths of the toes compared by manual reposition of the second MTP joint. In this case, proximal osteotomy of the first metatarsal on the hallux valgus and single-stage bone lengthening of the second metatarsal with iliac bone grafting on the second brachymetatarsia were performed. One year after the operation, the callosity of the third toe resolved and the clinical scores were improved. In the case of a hallux valgus deformity with second dorsal dislocation of the toes, surgeons should consider that there are rare cases with second metatarsal shortening. When hallux valgus associated with second brachymetatarsia is diagnosed, second metatarsal lengthening should be considered in addition to hallux valgus surgery.

Aetiology, diagnosis, and treatment of brachymetatarsia: a narrative review

Brachymetatarsia (BM), or hypoplastic metatarsal, is an abnormal shortening of one or more metatarsal bones with a female-to-male ratio of 10.53:1. Different causes are described in the literature, such as congenital, acquired, or iatrogenic, associated with different conditions and syndromes. Its presence may develop deformity and pain; however, often feet are pain free and the major worries of patients are cosmetics. Non-operative treatments aim to improve the comfort of metatarsal heads and the possible dorsal conflict through comfortable shoes or the use of specific orthotics. The surgical treatment is anything but straightforward, with "one-stage" or "two stage" techniques, the latter better called "by gradual distraction". One-stage procedures are more rapid techniques but have limited ability to restore the desired length due to neurovascular compromise caused by acute lengthening. Insufficient correction is also possible. On the contrary, by gradual distraction procedures allow gradual distraction lengthening of more than 1.5 cm, but require the use of an external fixator, with a higher risk of complications in more than about 50% of surgeries. The adjacent metatarsal shortening should be considered in combination with other techniques, to diminish the excessive lengthening. In each case, surgeries should be always decided on each patient's concerns, deformities, and clinical needs.

Brachymetacarpia and brachymetatarsia: do we need to operate?

Brachymetacarpia and brachymetatarsia are rare congenital presentations denoted by shortening of metacarpals and metatarsals respectively, in which the deformity usually presents around childhood/early adolescence.

The aetiology is usually congenital besides several other syndromic or endocrinologic associations.

Cosmetic issues such as absence of a normal-looking knuckle while making a fist or disruption of finger-tip curvature besides functional issues are the main indications for surgical intervention in brachymetacarpia.

In the foot, apart from cosmetic issues, pain due to transfer metatarsalgia as well as callosities along with toe deformities which lead to difficulty of using footwear are the main indications for intervention.

Lengthening of the affected bone, either acute with grafting or gradual, is the mainstay of treatment. Gradual lengthening can be either single-stage as in callotasis, or two-stage where the primary procedure is followed by bone grafting after the length has been achieved.

Adolescence, specifically between 12 and 15 years, is the preferred period for surgical intervention in these cases.

Cite this article: EFORT Open Rev 2021;6:15-23. DOI: 10.1302/2058-5241.6.200087

Literature Review on Brachymetatarsia

Brachymetatarsia is a malformation characterized by an abnormal reduction in the length of 1 or more metatarsal bones. It occurs because of early closure of the growth plate of the affected metatarsal. Generally, it is caused by a congenital disorder and it usually occurs bilaterally. With a greater prevalence in females, it most often affects the fourth metatarsal, followed by the first metatarsal. Surgical treatments proposed include using external mini-fixators or bone grafts in a single step to lengthen the metatarsal. In this review, 62 scientific articles about brachymetatarsia were analyzed with key demographic and epidemiological aspects of this pathology. The prevalence of bilateral brachymetatarsia was 47%, and the female to male ratio was 10.53:1. Both these findings appear to contradict the usual data reported for brachymetatarsia. A better understanding of this disorder will enable an appropriate therapeutic approach according to the psychological and social profile of affected individuals.

Novel mutations in HINT1 gene cause the autosomal recessive axonal neuropathy with neuromyotonia

Autosomal recessive axonal neuropathy with neuromyotonia (ARAN-NM) is a rare form of hereditary neuropathy. Mutations in HINT1 gene have been identified to be the cause of this disorder. We report two unrelated patients who presented gait impairment, progressive distal muscle weakness and atrophy, neuromyotonia and foot deformities. Electrophysiological studies showed axonal motor neuropathy and neuromyotonic discharges. Using Next-generation sequencing, we identified two homozygous mutations, NM_005340.6: c.112T > C; p.(Cys38Arg) and NM_005340.6: c.289G > A; p.(Val97Met) in HINT1 gene. Based on the clinical presentation and molecular genetic analyses, ARAN-NM was diagnosed in both patients and NM_005340.6: c.112T > C; p.(Cys38Arg) and NM_005340.6: c.289G > A; p.(Val97Met) in HINT1 gene were believe to be causative for the disorder.

Distraction osteogenesis of fourth brachymetatarsia

BACKGROUND

Brachymetatarsia is a rare congenital or developmental condition that results in a short metatarsal. The condition most commonly affects the fourth metatarsal of young and adolescent females. It does not usually produce a functional problem. However, it may produce a significant cosmetic problem especially in young women. The authors present their experience in gradual distraction of the fourth metatarsal to tackle this problem in adults.

METHODS

That was done using a monolateral frame in 11 feet of female patients with an average age of 23 years. Evaluation depended upon the achievement of the target length, angulation, pain, and satisfaction of the patient.

RESULTS

There were eight excellent and three good results after an average follow up of 2.6 years. Aside from nine cases of mild pin-tract infection, complications were few and minor.

CONCLUSIONS

We recommend distraction osteogenesis as the treatment of choice for brachymetatarsia of the fourth toe.

Brachymetatarsia with accessory navicular in right foot: A rare coincidental finding

A 33 years old female patient presented with posttraumatic pain in the right foot for which radiographs of the right foot was advised. No fracture was detected on radiographs and patient was managed conservatively on medications and posterior splint immobilization. We found coincidentally a short fourth metatarsal and an accessory navicular bone in the right foot radiographs. After 3 weeks of immobilization, she underwent mobilization of the right foot, weight bearing and intensive physio- therapy for 6 weeks. After two months of injury she was still complaining of pain on the plantar aspect of right foot which was diagnosed as metatarsalgia and operated on by excision of the neuroma present in the 3rd web space of the right foot. After surgery she was completely relieved of pain and could do activities well related to the right foot.

Callus Distraction Versus Single-Stage Lengthening With Bone Graft for Treatment of Brachymetatarsia: A Systematic Review

Brachymetatarsia deformity is a cosmetically displeasing anomaly that can become physically symptomatic. The surgical techniques most commonly used to repair the anomaly include single-stage lengthening with a bone graft, callus distraction, or a combination of bone grafting and callus distraction. A systematic review of the published data was performed to compare the outcomes of these 3 surgical procedures. A total of 61 studies reporting the use of callus distraction or single-stage lengthening, or both, for the treatment of brachymetatarsia were included in the present review. The incidence of major postoperative complications after callus distraction, single-stage lengthening, and the combination procedure was 49 (12.62%), 13 (3.72%), and 3 (33.33%), respectively. The number of minor complications with callus distraction, single-stage lengthening, and the combination procedure was 152 (39.18%), 55 (15.76%), and 1 (11.11%); the mean percentage of the original length achieved was 37.36%, 25.98% and 36.00%; and the mean length achieved was 17.5, 13.2, and 14.0 mm, respectively. The healing index (mo/cm) and healing time was 2.31 and 16.04 weeks, 1.90 and 9.35 weeks, and 3.93 and 14.62 weeks for callus distraction, single-stage lengthening, and the combination procedure, respectively. Our findings indicate that the callus distraction technique is associated with greater length gained but results in greater complication rates and requires almost twice the time to heal. Single-stage lengthening with a bone graft was associated with fewer complications and faster healing times than callus distraction but with lesser gains in length. From the information reported in the studies we reviewed, the prevalence of bilateral brachymetatarsia was 44.52%, and the female/male ratio was 13.7:1. Both of these findings seem to contradict the usual data given (72% for bilateral brachymetatarsia and a female/male ratio of 25:1).

A modified surgical technique for lengthening of a metatarsal using an external fixator

Brachymetatarsia is a congenital or developmental condition that results in a short metatarsal. Problems that arise from this condition can include pain, difficulty with shoe wear, and cosmetic concerns. Multiple techniques have been described that successfully correct the deformity, including both acute and gradual distraction. We describe a modification of the technique of gradual lengthening by way of distraction osteogenesis in which an axial transarticular K-wire is incorporated into a monolateral frame, thereby increasing the stability of the construct and potentially minimizing complications.

One-stage metatarsal lengthening by allograft interposition: a novel approach for congenital brachymetatarsia

BACKGROUND

Congenital brachymetatarsia, a shortened metatarsal bone, can be corrected surgically by callus distraction or one-stage lengthening using bone graft.

QUESTIONS/PURPOSES

We asked whether one-stage metatarsal lengthening using metatarsal homologous bone graft could improve forefoot function, lead to metatarsal healing, restore metatarsal parabola, and improve cosmetic appearance.

PATIENTS AND METHODS

We retrospectively reviewed 29 patients (41 feet) in whom we lengthened 50 metatarsals. Surgery consisted of a transverse proximal osteotomy of the metatarsal shaft and interposition of a metatarsal homologous bone graft (average, 13 mm long) fixed with an intramedullary Kirschner wire. Minimum followup was 3 years (mean, 5 years; range, 3-11 years).

RESULTS

Bone union was achieved in all cases. The mean preoperative American Orthopaedic Foot and Ankle Society score was 37 points (range, 28-53 points) and the mean postoperative score was 88 points (range, 74-96 points), with an average improvement of 51 points. Radiographically, the mean gain in length was 13 mm (range, 10-15 mm), and the mean percentage increase was 23%.

CONCLUSIONS

One-stage metatarsal lengthening using interposition of metatarsal homologous bone graft to correct congenital brachymetatarsia has low morbidity for the patient, limited complications, short recovery times, and restores forefoot anatomy.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Strategies for managing massive defects of the foot in high-energy combat injuries of the lower extremity

Blast-related lower extremity trauma presents many challenges in its management that are not frequently experienced in high-energy civilian trauma. Because many of the blasts experienced in the current conflicts are ground based, the foot and ankle have sustained considerable severity and extent of injury because of the proximity of the blast. The high functional demands required of active service members create several reconstructive challenges. The authors' experience in the current conflicts has shown a similar trend, with the magnitude of soft tissue injury usually dictating whether or not salvage may be possible. Several reconstructive options for bone defect management are outlined and discussed.

Lengthening of the first metatarsal through an arthrodesis site for treatment of brachymetatarsia: a case report

Brachymetatarsia of the first metatarsal is an uncommon condition, but one that is amenable to treatment by lengthening via distraction osteogenesis, a process that employs 2 groups of pins of an appropriate external fixator inserted in the metatarsal to apply gradual distraction across an intervening osteotomy. We present the case of a female, aged 13 years, who presented with congenital bilateral first brachymetatarsia and left foot pain due to transfer metatarsalgia. The short and plantarflexed first ray could not accommodate both groups of fixator pins, even with the fixator set at its shortest length. An alternative strategy was devised that reduced the degree of plantarflexion using a tarsometatarsal arthrodesis, which effected subsequent lengthening through the healing fusion site. Lengthening commenced after 10 days and continued over a period of 52 days, at a rate of 0.5 mm to 1.0 mm per day. Consolidation occurred at 20 weeks with a final increase in length of 25 mm. The patient returned to vigorous sporting activity 1 year after removal of the fixator. To our knowledge, this is the first account of a metatarsal-lengthening arthrodesis at the tarsometatarsal level.

Morphometric study of the human metatarsals and phalanges

Mathematical relation between metatarsals and between phalanges in terms of their lengths and widths in themselves is considered to be significant with respect to its functional and aesthetic roles. The objective of this study is to conduct measurements for determining lengths and widths of metatarsals and phalanges on the foot radiographs and to determine possible mathematical correlations between metatarsals themselves and between phalanges themselves in terms of their lengths and widths. Anteroposterior right and left foot radiographs were taken from 100 volunteers (50 men and 50 women). Lengths and widths of the metatarsals and phalanges were measured in millimeter on radiographs. The mean, minimum and maximum values, and standard deviations of each bone's length and width were studied and data were put into formulation. The results were evaluated by Regression statistical test, and the relation between metatarsals and between phalanges in terms of their lengths and widths was studied. As a result of the measurements, we found fixed proportions between metatarsals in themselves and between phalanges in themselves in terms of their lengths and widths. Knowing these morphometric relations may be useful for performing any surgical procedures designed to manage any defects or imperfections of the foot, chief among them is shortness.

Use of internal callus distraction in the treatment of congenital brachymetatarsia

Congenital bilateral brachymetatarsia of the fourth metatarsal bone was treated by osteotomy and bone lengthening using the internal distraction technique. The patient was cosmetically improved. This technique has some advantages over the method of external distraction.

Metatarsal lengthening by callus distraction for brachymetatarsia

Twelve metatarsal lengthening procedures by callus distraction were performed in seven patients with brachymetatarsia. The mean age at the time of the surgery was 12.0 years (range, 11.1-14.5 years). The mean duration of follow-up was 5.2 years (range, 1.2-13.5 years). The bones were lengthened at a rate of 0.7 mm/day by a mean of 20 mm (range, 15-30 mm), which was 45% of their original length (range, 37-61%). The mean healing index was 73 days/cm (range, 41-98 days/cm). Corrective shortening osteotomy was performed in one case in which the metatarsophalangeal joint was dislocated due to excessive lengthening. In 10 of the remaining 11 cases, joint stiffness, narrowing of the joint space and some degree of plantar subluxation of the metatarsophalangeal joint were observed during distraction, but these were gradually resolved without either elongation of the tendon or metatarsophalangeal joint fixation with Kirschner wire.

Metatarsal lengthening

Metatarsal lengthening for brachymetatarsia is a good procedure that can improve appearance and function. There are risks to these procedures, which should be understood thoroughly.