The Surgical Treatment of Brachymetatarsia

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.

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.