Introduction: It has long been recognized that free flaps performed in the first few days after injury are associated with lower rates of infection and flap loss. However early wound closure is not always possible due to medical instability, the presence of life-threatening injuries, or operating room availability. Subatmospheric dressings have been shown to have several beneficial effects upon wounds including promoting granulation and inhibiting bacterial growth. The purpose of this study is to review a large clinical experience with the management of Gustillo 3B and 3C distal tibia fractures to determine if the use of a subatmospheric dressing as a “bridge” to free tissue transfer has affected complication rates.

Methods: The records were reviewed of 105 consecutive patients who underwent a free muscle flap for treatment of a Gustillo 3B or 3C distal tibia fracture between 1991 and 2005. Patients were divided into three groups: acute (flap performed in the first 7 days post-injury), subacute (days 8-42), and chronic (>42 days). The three groups were tested for homogeneity and compared using five outcome measures: rate of infectious complication, flap-related complications, number of surgical procedures, length of hospital stay, and time to bony union. The subacute group was further divided into those patients who underwent subatmospheric dressing therapy prior to free tissue transfer and those who did not, and the five outcome measures were compared between these two subgroups using the Student's t-test.

Results: The study group included 72 men and 33 women, ranging in age from 6 to 78 years (median 39). There were 32 patients in the acute group, 55 in the subacute group, and 18 in the chronic group. No significant differences were observed between the three groups regarding age, mechanism of injury, premorbid conditions, or flap choice. The overall complication rate in the subacute group was 47% compared to 39% in the chronic group and 31% in the acute group (p<0.05). The rate of infectious complication, (defined as osteomyelitis, infectious nonunion, cellulitis, or abscess), was significantly higher in the subacute group (15%) than in the acute (9%) or chronic groups (11%). Flap-related complications were higher in the subacute (18%) and chronic groups (17%) than in the acute group (9%). There were no statistically significant differences noted between the three groups for number of surgical procedures or length of hospital stay. Time to bony union was significantly shorter in the acute group (4.2 months) than the subacute (6.5 months) or chronic groups (6.2 months). Patients in the subacute group who underwent subatmospheric dressing therapy between injury and free flap had a significantly lower overall complication rate (35%), infectious complication rate (6%), and flap related complication rate (12%) than those who did not (53%, 18%, and 21%, respectively, p<0.05). There were no significant differences observed for number of procedures or length of hospital stay, but the time to bony union was significantly less in the subatmospheric dressing group (4.9 months versus 7.2 months, p<0.05).

Conclusions: The use of a subatmospheric dressing as a “bridge” to free flap reconstruction in patients with Gustillo 3B and 3C tibia fractures was associated with a reduced complication rate in the present study. Patients who received subatmospheric dressing therapy prior to undergoing free flap transfer in the subacute period (days 7-42) had a complication profile similar to those patients who underwent closure in the acute period (days 1-7). This suggests that the use of a subatmospheric dressing, by promoting a healthy wound environment and reducing bacterial counts, may effectively extend the acute period when free tissue transfer in the first 7 days is not possible.
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