Pseudarthrosis after postoperative wound infection in the lumbar spine.

This retrospective investigation attempts to define the incidence of fusion success after postoperative infection after a posterior lumbar fusion, as well as which risk factors may adversely affect arthrodesis after successful debridement. At an average follow-up of 37 months, 18 of 29 patients (62.1%) had a successful arthrodesis. Eighty-seven percent of patients whose fusion excluded the sacrum had a solid arthrodesis, compared with only 36% of those fusions including the sacrum. The fusion rate in female patients was 33.3%, compared with 82.4% in male patients. The rate of fusion with allograft bone was 17.2 versus 83.3% with autograft bone. Female sex, the use of allograft bone, and extension of the fusion mass to the sacrum significantly increase the incidence of nonunion after a postoperative deep spinal wound infection.