Grade 3B open tibial fractures are a result of high energy trauma and mandate urgent reconstruction of soft tissue and bone defects after the decision to salvage the extremity is made. The bone healing requires healthy soft tissues coverage therefore treatment with Ilizarov distraction osteogenesis after flap coverage of tissue defects is a promising modality in these complex injuries. However the obliteration of the bone defect by the flap is a problem. In order to overcome this, an antibiotic spacer is placed under the flap tissue between the bone ends prior to distraction.
Nineteen extremities of eighteen patients treated with soft tissue flap and ilizarov bone lengthening have been evaluated in our retrospective case series. The size of the bone defect varied between 2 and 15 cm. According to the usual plan, multiple debridements were done after external fixation of the fracture. Cement spacer impregnated with antibiotic was placed in bone defects that were greater than 6cm. A muscle flap was used to cover the spacer. 4 patients were treated with local flaps and 14 patients were treated with free flaps. The external fixator was then replaced with and Ilizarov distraction device and proximal or distal osteotomies were done. The segmental lenghtening of the bone took place in the tunnel formed by the spacer under the flap in 13 patients. No serious flap complication was encountered during the course of distraction. At the end of the distraction period, the Ilizarov device was removed.
The patient files were retrospectively evaluated for age, gender, mechanism of injury, location of the bone defect, and concomitant arterial injuries. Type of flap, anastomosis type (end to end versus end to side), recipient artery, time in weeks prior to flap surgery, number of debridements prior to flap surgery, and the use of temporary antibiotic spacer were examined with regard to the following: Flap loss, Ilizarov frame time, docking site nonunion, equinus deformity and functional results.
The free flap survival rate was 88 %. The duration of the Ilizarov lenghtening ranged between 14 to 119 weeks. Functional extremities were obtained in all patients at the end of the treatment. With regard to the complications related to bone; 2 patients had fractures of the reconstructed bone, 3 patients had revision surgery for equinus deformity, and 8 patients had revision surgery of the docking site. No osteomyelitis or serious soft tissue infection was encountered.
Findings indicate that Ilizarov and flap treatment for grade 3B open tibia fractures can be benefical in terms of limb salvage with adequate bone quality. Additional morbidity is prevented compared with vascularised and nonvascularised bone graft harvesting modalities used for bone reconstruction. The antibiotic spacer with flap coverage is found to be harmless against flap survival and can be used safely to improve clinical outcomes.
KEYWORDS:
grade 3B tibia fracture, bone gap, Ilizarov, flap, spacer