Metatarsal lengthening by distraction osteogenesis for brachymetatarsia in paediatric patients: is it safe and effective?

PURPOSE

The primary aim is to assess the efficacy of the surgical callus distraction technique of the metatarsus in paediatric patients. Secondary objectives are to assess complications and treatment duration. We have also described the details of our surgical technique.

MATERIALS AND METHODS

A case series review of paediatric patients who had metatarsal lengthening at our unit between 2014 and 2022. Patient demographics, duration of time in frame, complications and metatarsal length achieved were recorded. The AOFAS Midfoot and the MOXFQ were taken pre-operatively and at final follow-up.

RESULTS

Sixteen metatarsals in 8 patients (14 feet) underwent lengthening between 2014 and 2022 using the MiniRail OrthoFix 100 (Orthofix Medical Inc, Lewisville, TX, USA). The mean age was 13.3 (12-17) years. The average duration between surgery and implant removal was 5.2 months. According to Paley's classification, there was one obstacle encountered in a patient who required a revision of their osteotomy and one problem in another patient who had an infected metatarsophalangeal joint stabilising k-wire treated with oral antibiotics. The Mean AOFAS Midfoot score improved from 53.10 to 86.40 (p < 0.0001) and the Mean MOXFQ improved from 32.5000 to 12.1250 (p < 0.05); these were statistically significant.

CONCLUSION

Gradual metatarsal lengthening using the MiniRail external fixator is a safe and effective method to treat brachymetatarsia in paediatric patients. This preliminary report describes and supports metatarsal lengthening in appropriate patients. Holistic care in terms of a pre-operative assessment, psychological support and preparation for the extended rehabilitation period are vital.

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.

Callus distraction for brachymetatarsia - A comparison between an internal device and the external fixator

BACKGROUND

Symptomatic patients with severe brachymetatarsia are commonly treated with callus distraction using external mini-fixator (EF) or internal device (ID). This study points out advantages and limitations of both methods comparing clinical and radiographical parameters.

METHODS

Retrospective analysis of 21 metatarsal bones in twelve patients. Twelve metatarsals were treated with ID (Genos Mini), nine with EF (MiniRail).

RESULTS

Mean lengthening distance was 17.3 mm using EF and 11.7 mm using ID (p = 0.016). Adverse results were observed in 89% of metatarsals treated with EF and in 33% treated with ID (p = 0.011). Postoperative surgical intervention was required in 33% using EF compared to 0% using ID (p = 0.031). Mean total German Foot Function Index (FFI-T) improved from 49 to 33 using EF and from 47 to 22 using ID (p < 0.001).

CONCLUSION

CD is a reliable surgical treatment for BMT. Surgeons should be aware of implant-related advantages and complications when counseling patients about treatment options.

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.

Novel phenotype and genotype spectrum of NARS2 and literature review of previous mutations

BACKGROUND

Mutations in NARS2 (MIM: 612803) are associated with combined oxidative phosphorylation deficiency 24 (COXPD24; MIM: 616239) that is a rare mitochondrial and a multisystem autosomal recessive disorder.

AIMS

We aimed to detect the underlying genetic factors in two siblings with progressive ataxia, epilepsy, and severe-to-profound hearing impairment.

METHODS

After doing medical assessments and pertinent tests (i.e., auditory brainstem responses, pure tone otoacoustic emission test, cardiac examinations, computed tomography, and electroencephalogram), because of the clinical and probable genetic heterogeneity, whole-exome sequencing was performed, and co-segregation analysis was confirmed by Sanger sequencing. Biological impacts of the novel variant were evaluated using sequence-to-function bioinformatics tools.

RESULTS

A novel homozygous missense variant, NM_024678.6:c.545 T > A; p.(Ile182Lys), in exon 5 of NARS2 was identified in both patients and verified by Sanger sequencing. In silico analyses introduced this variant as pathogenic. Mitral valve prolapses with mild regurgitation, brachymetatarsia, severe hallux valgus, and clubbed fingers were reported as novel manifestations in association with NARS2 gene. By doing a literature review, we also underscored the high heterogeneity of disease phenotype.

CONCLUSIONS

Herein, we report some novel phenotype and genotype features of two female patients in an Iranian consanguineous family with COXPD24, caused by a variant in NARS2-NM_024678.6: c.545 T > A; p.(Ile182Lys). Moreover, our data expanded the phenotype and genotype spectrum of NARS2-related disorder and confirmed an unpredictable nature of genotype-phenotype correlation in COXPD24.

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.

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.

Three cases of brachydactyly type E from two commingled tombs at the Late Intermediate period - Late Horizon site of Marcajirca, Ancash, Peru

OBJECTIVE

Here we present the first known examples of brachydactyly from an Andean archaeological context by describing the affected bones, presenting a differential diagnosis, and discussing the cultural implications of there being shortened metapodials in multiple tombs.

MATERIALS

3232 well-preserved tubular bones representing an MNI of 250 human adults.

METHODS

Each bone was visually inspected. Measurements were taken with an osteometric board, sliding calipers, and a flexible tape measure.

RESULTS

Of 1210 metapodials excavated from eight burial contexts, ten were atypically short.

CONCLUSIONS

The ten shortened elements represent an MNI of three individuals with brachydactyly from two tombs. The presence of at least two individuals with brachydactyly in one tomb adds support to a previous suggestion that tombs were used for familial interment. It is plausible that the third individual from a different tomb was related to the other two, and the different burial contexts may reflect postmarital practices.

SIGNIFICANCE

These cases offer insight into tomb use and underscore the importance of identifying rare developmental anomalies in the archaeological record as their presence may indicate genetic relationships within or among archaeological cemeteries.

LIMITATIONS

With commingled contexts and incomplete recovery of skeletal remains, individualizing the brachydactylous elements was not possible. There is also a lack of comparative data from other Andean sites.

SUGGESTIONS FOR FURTHER RESEARCH

Identify more Andean cases of brachydactyly to learn if the relatively frequent involvement of the first digit is more common among Andean skeletal samples than North American, or if it is unique to Marcajirca.

Value of ultrasonography and radiography for the study of bone regeneration in lengthening of the fourth ray in brachymetatarsia

BACKGROUND

Distraction osteogenesis is frequently used for brachymetatarsia.

METHODS

Brachymetatarsia of the fourth ray was treated with the Ilizarov method in 10 females. Distraction rate was 1.00-0.75mm a day. Radiography and ultrasonography were used to study the regeneration course throughout the distraction and fixation phases.

RESULTS

Mean lengthening achieved was 2.28cm in the average distraction period of 30.2 days and average fixation phase of 50.2 days. Ultrasonography detected the regeneration signs and zonal structure of the regenerate earlier than radiography. It confirmed slow regeneration in two patients and their distraction rate was corrected. One patient had premature consolidation on distraction day 10 and needed re-osteotomy.

CONCLUSIONS

Combination of radiography and ultrasonography to study bone regeneration in brachymetatarsisa provides a better monitoring of distraction callus progression. Ultrasonography is of great value to detect regeneration problems during early stages of lengthening.

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.

Brachymetatarsia: One-stage Versus Two-Stage Procedures

Brachymetatarsia is a rare deformity with controversial clinical presentation. Multiple acute and gradual lengthening surgical techniques have been described for correction of this type of foot deformity. All techniques try to create a better appearance, facilitate shoeing, or solve possible transfer metatarsalgia. Either acute lengthening (1-stage procedure) or gradual lengthening (2 stages) is selected based on the patient's deformities, concerns, and clinical needs.

A rare case of isolated congenital unilateral brachymetatarsia presenting in a young adult male

Congenital brachymetatarsia is a rare skeletal anomaly which is characterized by the abnormal length reduction of one or more metatarsal bones. It occurs as the result of the early closure of the growth plate. While the majority of the reported cases are idiopathic, it can also be seen in association with various genetic conditions or syndromes. Brachymetatarsia most commonly involves the fourth metatarsal followed by the first metatarsal. This rare disorder is mostly bilateral and reported almost exclusively in females. Herein, we present a rare case of congenital unilateral brachymetatarsia which was incidentally detected in a young adult male.

Complications of distraction osteogenesis in brachymetatarsia: Comparison between the first and fourth brachymetatarsia

BackgroundRecently, distraction osteogenesis has been widely used to treat brachymetatarsia. However, few papers have compared complications associated with this treatment. The purpose of the present study was to compare the complications between the first and fourth brachymetatarsia treated by distraction osteogenesis. MethodsWe performed distraction osteogenesis to 83 metatarsals in 41 patients between 1999 and 2012. A total of 30 metatarsals received treatment for the first metatarsal (Group A) while 53 metatarsals received treatment with the fourth metatarsal (Group B). ResultsThe complication rate in Group A (40%) was higher than that in Group B (18.9%). Those who had high percentage of lengthening gain were more likely to have complications. A cut-off value for lengthening gain developing complication was 41.3%. ConclusionComplication incidence after distraction osteogenesis was increased when lengthening gain was more than 41.3% for brachymetatarsia. In the 1st metatarsal lengthening, the most common complication was stiffness. In contrast, complications of the 4th metatarsal lengthening were pin-track infection and angular deformity.

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.

Results of distraction callus osteogenesis in hand and foot in Iran: A 15-year experience

BACKGROUND

Distraction osteogenesis (DS) is currently an important technique for lengthening shortened bones of the hand and foot. Authors report their experience in applying DS for various conditions of the hand and foot using a distractor that the senior author has designed.

MATERIALS AND METHODS

Records of patients who underwent DS for hand and foot conditions in a private clinic were retrieved between January 2001 and January 2015. Data concerning distraction, outcome, and complications were recorded.

RESULTS

There were 17 patients, 7 males, and 10 females with a total 24 distractions. The mean length gained was 21.2 mm (1.69) and the mean total treatment time was 198.58 (15.88) days. Overall, complications occurred in 9 (37.5%) distractions. Major complications occurred in 2 (8.33%) of distractions. Minor complications occurred in 7 (29.2%) distractions.

CONCLUSION

DS is an effective modality for lengthening bones of the hand and feet for both traumatic and congenital conditions. Joint stiffness/contracture is an important complication following DS of the metatarsals.