The Effect of Free versus Local Flaps on Time to Union in Open Tibia Fractures

Background: Early soft-tissue reconstruction of open fractures has been shown to decrease infection rates and improve rates of bony union. The purpose of this study was to compare the rates and time to union of open tibia fractures that underwent soft-tissue coverage. Methods: A retrospective chart review of 118 patients with open tibia fractures requiring soft-tissue reconstruction treated at a single level 1 trauma center was performed. Demographic data as well as flap type were collected. Union status was determined using modified Radiographic Union Scale in Tibia Fractures score greater than 11. Results: Limb salvage was achieved in 90% of patients. The overall rate of nonunion was 33%. Flap type significantly affected time to union, with local fasciocutaneous and keystone flaps having significantly longer time to union [202 days (SD 120.3)] than all other flap groups (P = 0.01). Free flaps had significantly shorter time to union than local flaps [115 days (SD 49.6) versus 149 days (SD 75.4); P = 0.02]. Muscle flaps had significantly shorter time to union than fasciocutaneous flaps [123 days (SD 52.4) versus 165 days (SD 104.1); P = 0.04]. This remained true after controlling for fracture location, patient age, need for second flap, and fixation method (P = 0.037). Patients who underwent an initial soft-tissue reconstruction with a local muscle flap were more likely to require a second flap to achieve wound closure (OR, 3.7; P = 0.008) and needing a second flap significantly increased time to union [162 days (SD 95.9) versus 122 days (SD 51.9); P = 0.03]. Conclusion: Flap type affects time to union but not nonunion rate in open tibia fractures. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.