The impact of deep surgical site infection on surgical outcomes after posterior adult spinal deformity surgery: a matched control study.

PURPOSE: The impact of deep surgical site infection (SSI) on surgical outcomes after adult spinal deformity (ASD) surgery is still unclear. We aimed to study the morbidity of SSI in ASD and its impact on deformity correction and functional outcome. METHODS: Prospective multicenter matched-cohort study including consecutively enrolled ASD patients. Patients developing SSI were matched to similar controls in terms of age, gender, ASA, primary or revision, extent of fusion, and use of tri-columnar osteotomies. Preoperative parameters, surgical variables, and complications were recorded. Deformity parameters and Health Related Quality of Life (HRQoL) scores were obtained preoperatively and at 6, 12, and 24 months. Independent t test and Fischer's exact test were used for comparisons. RESULTS: 444 surgical ASD patients with more than 2 years of follow-up were identified. 20 sustained an acute SSI and 60 controls were accordingly matched. No differences were observed between groups in preoperative radiological and HRQoL variables confirming comparable groups. SSI patients had longer hospital stay and more mechanical complications including proximal junctional kyphosis. Infection was associated with more unrelated complications and revisions. Deformity correction was maintained equally at the different time intervals. One death was related to SSI. SSI patients had worse overall HRQoL status at 1 year and were less likely to experience improvement. However, no significant differences were recorded thereafter. CONCLUSION: SSI significantly affects the first postoperative year after posterior ASD surgery. It is associated with more complications, unrelated revisions, and worst quality of life. However it's negative impact seems to be diluted by the second postoperative year as differences in HRQoL scores between the two groups decrease. These slides can be retrieved under Electronic Supplementary material.