A Combined Use of a Free Vascularised Flap and an External Fixator for Reconstruction of Lower Extremity Defects in Children

Abstract

To describe a combined use of a free vascularised flap and an external fixator for reconstruction of lower extremity defects in children, and correction of equinus contracture developed after removal of the external fixator using a circular dynamic frame. Seven children (4 males) aged 4 to 12 (mean, 8) years were treated with 9 free vascularised flaps for 8 limbs (bilaterally in one patient and for a failed flap in another). Patient pathologies included: 3 soft tissue degloving injuries, one soft tissue and bone avulsion, one severe burn contracture, one resurfacing of soft tissue and bone necrosis, and one osteosarcoma resection defect. Free flap reconstruction was delayed in 6 patients (range, 3 weeks to 4 years). Static external fixators were used to stabilise the free vascularised flaps at the time of reconstruction, with the ankle in a neutral position. The mean follow-up was 5 (1-10) years. All flaps but one survived; the failed one was immediately reconstructed with a contralateral, latissimus dorsi flap. One anastomosis following a Kirschner-wire injury was successfully revised. Six patients had pin tract infections and were treated with oral antibiotics. Two patients developed equinus contracture 6 and 3 years later, after removal of the external fixator, and were corrected by distraction, using a dynamic Ilizarov frame. The combined use of a free flap and an external fixator for salvage of lower extremities is useful in children. Late development of equinus contracture can be safely corrected by distraction, without compromising flap viability.