[Vacuum-assisted closure therapy for the treatment of acute postoperative osteomyelitis]

Vacuum-assisted closure is used frequently for the treatment of posttraumatic osteomyelitis of the extremities. After debridement and repeated VAC dressing changes, the wounds are closed by secondary suture, split-thickness skin grafts or local flaps. However, no objective parameters describe the time point for secondary wound closure. Our thesis was that negative microbiological results from bone specimens can indicate the time for secondary wound closure. Moreover, treatment course and clinical outcome after 3.4 years should be compared to those of other surgical approaches for acute postoperative osteomyelitis from the literature.

43 patients with acute postoperative osteomyelitis of the extremities and the pelvis were treated by serial bone and soft tissue debridements and VAC therapy and analysed prospectively. Debridements were repeated until the wounds were macroscopically free from signs of infection (good granulation/no necrosis). During each revision a bone specimen was taken for microbiological analysis. Number of revisions, bacterial cultures, type of wound closure and recurrence of infection after 3 years and 5 months on average after the last surgery was analysed.

9.8 debridements on average were performed until eradication of infection and secondary wound closure. Despite the absence of macroscopic infection, bacteria were still found in bone samples from 15 of 43 patients. Three biopsies were free of bacteria for the first time right before wound closure, 25 samples had become negative during the treatment. Six recurrences (19.3 %) were noted after 3.4 years on average. Four patients from the group of negative bone biopsies (19 %) and two patients from the group of persisting bacteria before secondary closure (20 %) had a recurrence of infection.

In about one third of the bone biopsies bacteria persisted. This bacterial load had no correlation to wound healing and rate of recurrence after over 3 years. In conclusion, microbiological bone samples are not suitable as an indicator for the time point of secondary wound closure. Compared to other treatment options in acute postoperative osteomyelitis from the literature (especially implantation of local antibiotics), no advantage of vacuum-assisted closure could be shown concerning number of debridements and rate of recurrences.