Short-Term Wound Complications After Application of Flaps for Coverage of Traumatic Soft-Tissue Defects About the Tibia*

BACKGROUND: The purpose of the present study was to compare the rate of short-term wound complications associated with rotational flaps and that associated with free flaps for coverage of traumatic soft-tissue defects about the tibia. METHODS: Of 601 patients prospectively enrolled in a multicenter study of high-energy trauma of the lower extremity, 190 patients (195 limbs) required flap coverage and had six months of follow-up. The injury data included the ASIF/OTA classification of the tibial fracture and the soft-tissue injury and the functional status of the neurovascular and muscular structures of the soft-tissue compartments at the time of soft-tissue coverage. The treatment data consisted of the type of flap, the timing of the flap coverage, and the type of fixation. The patient characteristics that were recorded included the age, gender, presence of comorbidities, and smoking status at the time of the injury. Short-term complications included wound infection, wound necrosis, and loss of the flap within the first six months after the injury. RESULTS: Eighty-eight limbs were treated with a rotational flap, and 107 limbs were treated with a free flap. Overall, complications occurred after fifty-three (27 percent) of the 195 flap procedures; forty-six (87 percent) of the fifty-three required operative treatment. The two treatment groups were similar with respect to age, gender, comorbidities, preinjury smoking status, ASIF/OTA classification of the fracture, and prevalence of vascular injury requiring repair (p>0.05). There were two important differences between the two groups. First, three of the four leg compartments--that is, the anterior, lateral, and deep posterior compartments--were more likely to be functionally compromised in the free-flap group than in the rotational flap group (p<0.05), suggesting that patients in the free-flap group had sustained more severe soft-tissue injuries. Second, the Injury Severity Score was significantly higher (p = 0.001) in the rotational flap group (mean, 14 points) than in the free-flap group (mean, 11 points), suggesting that patients in the former group had sustained more substantial total body trauma. Overall, there were no significant differences between the two groups with respect to the complication rates. However, among those with the most severe grade of underlying osseous injury (an ASIF/OTA type-C injury), 44 percent of the limbs that were treated with a rotational flap had a wound complication compared with 23 percent of the limbs that were treated with a free flap (p = 0.10). To control for any differences between the two groups with respect to the severity of the injury, the treatment methods, or the patient characteristics, multivariate regression modeling was performed. An interaction effect between the type of flap and the severity of the underlying osseous injury demonstrated significance (p<0.05) after controlling for other factors. Of the limbs that sustained an ASIF/OTA type-C osseous injury, those that were treated with a rotational flap were 4.3 times more likely to have a wound complication requiring operative intervention than were those treated with a free flap. No significant difference in the rate of complications was detected with respect to the type of flap used for the limbs that had lower-grade osseous injuries. CONCLUSIONS: We found that use of a free flap to treat limbs with a severe underlying osseous injury was significantly less likely to lead to a wound complication requiring operative intervention than was use of a rotational flap.