Ilizarov technique for foot and ankle deformity correction utilizes a circular external fixator (Ilizarov frame, Taylor Spatial Frame, or hexapod frames like TrueLok-Hex) consisting of rings connected by struts and threaded rods, attached to bone via tensioned wires and half-pins. The frame allows multidirectional gradual deformity correction through controlled distraction at osteotomy sites and joint distractions, with the fundamental principle that gradual stretching (1 mm/day, divided into 4 increments of 0.25 mm) allows soft tissues, blood vessels, and nerves to accommodate to changes that would not be tolerated in acute correction.
Indications include severe complex foot deformities (equinocavovarus from clubfoot residual or neurogenic causes, severe planovalgus, posttraumatic deformity, postsurgical deformity, congenital deformity such as fibular/tibial hemimelia, Charcot foot deformity), large limb length discrepancies, and combined deformity with shortening. Common surgical components: tibial osteotomy (supramalleolar, midshaft) for ankle/distal tibial deformity correction, calcaneal V-osteotomy (Tilo Knothe or Coleman) for hindfoot varus, midfoot V-osteotomy for cavus correction, joint distraction for ankle stiffness, and percutaneous Achilles tendon lengthening.
Treatment phases: surgical phase (osteotomies and frame application under fluoroscopy with careful soft-tissue handling, 2-3 hours surgery), latency phase (5-7 days waiting before distraction begins to allow initial callus formation), distraction phase (1 mm/day correction over weeks to months depending on severity, with weekly clinical and radiographic monitoring), and consolidation phase (frame remains in place after correction completion until full bone healing, typically 1-2x distraction time). Total frame time ranges from 3 to 6 months. Complications include pin site infections (50-90% incidence, mostly minor, treated with local care or antibiotics), pin loosening, premature consolidation requiring reosteotomy, malunion, neurovascular complications during distraction (rare), joint stiffness/contractures requiring physical therapy, and psychological burden of frame wear. Outcomes are generally favorable for severe deformities not amenable to acute correction, with 80-90% successful deformity correction and good functional outcomes when patient compliance is good. Modern hexapod frames with computer software for strut adjustment have largely replaced traditional Ilizarov for complex multiplanar deformities.