Radiographic Features Associated With Increased Surgical Invasiveness in Pyogenic Vertebral Column Osteomyelitis

STUDY DESIGN: Single center retrospective cohort study. OBJECTIVES: Assess the association between well-known radiographic features for spinal instability from the Spinal Instability in Neoplasia Score (SINS) and surgical invasiveness in treating vertebral column osteomyelitis (VCO). This will potentially help surgeons in surgical planning and aid in developing a pathology specific score. METHODS: Patients with VCO were identified from hospital coding. On preoperative computed tomography radiographic features, including spinal alignment, vertebral body collapse, location, type of bone lesion, and posterolateral involvement were assessed and scored 0 (stable) to 15 (highly unstable). Surgical invasiveness was graded as 0 = no surgery, 1 = decompression alone, 2 = shortening or posterior stabilization, or 3 = anterior column reconstruction. RESULTS: A total of 41 patients were included. The mean age of the cohort was 63.3 years (SD 12.0) with male comprising 78%. The mean total radiographic score for the nonsurgical group was 6.39 (3.14) and for the surgical group 10.38 (3.06), P < .001. Spinal alignment, vertebral body collapse, type of bone lesion, and posterolateral involvement correlated with surgical invasiveness (all Ps < .05). Subgroup comparison following analysis of variance showed that only spinal alignment was significantly different between groups 2 and 3. CONCLUSIONS: Our findings show correlation of the radiographic components of the SINS with surgical invasiveness in management of pyogenic VCO—these findings should aid development of an “instability score” in pyogenic VCO. While most radiographic features assessed correlated with surgical invasiveness spinal alignment appears to be the key feature in determining the need for more invasive surgery.