Revision surgery for chronic pyogenic spondylitis: analysis of a monocenter cohort with a minimum 1 year follow-up

Objective. To analyze the structure of complications and follow-up results of revision surgeries in patients operated on for chronic nonspecific spondylitis (CNS). Material and Methods. Revision interventions due to the development of complications corresponding to type IIIB according to Clavien – Dindo classification were performed in 78 patients (mean age 58 years 6 months ± 11 years 2 months) with CNS who had previously undergone reconstructive surgery on the spine. The timing of complications was analyzed according to Prinz classification. The structure of complications and factors potentially influencing their development were evaluated. Predictors of infectious and orthopedic complications were differentiated. Follow-up period was at least 1 year (M ± m = 3 years 3 months ± 1 year 2 months). Statistical analysis was performed using SPSS, version 22.0. Results. The estimated frequency of Clavien – Dindo grade IIIB complications after surgical treatment of CNS was 11.3 %. In 44 (56.4 %) of 78 cases, indications for revision surgery were due to infectious complications, and in 34 (43.6 %) – to orthopedic complications. The Charlson comorbidity index was 4.5 ± 1.8 with no intergroup differences between infectious and orthopedic complications (p = 0.052). The duration of primary interventions (p < 0.001) and blood loss (p = 0.010) were higher in patients with infectious complications. The average preoperative ODI was 48.3 ± 13, with a higher value in the infectious complications group (F = 5.146, p = 0.026). The timing of complications and the location of primary reconstruction influenced both the ODI score (F = 6.622, p < 0.001) and the type of complications (Pearson’s χ 2 = 14.224, p = 0.014). The patient age had no effect on the location of complications (p = 0.349, F value = 1.137). Preoperative neurologic deficit was noted in 23 patients, regression was recorded in 11 cases, including complete in 6 and within the same functional class in 5 cases. The complication rate in the long-term period after revision surgery was 14.1 %. Conclusion. Infectious complications of primary interventions in patients with chronic nonspecific spondylitis prevail over orthopedic ones. Significant predictors of the development of complications are the patient age > 55 years, the Charlson comorbidity index > 3, duration of surgery > 2 hours 30 minutes, and blood loss volume > 250 ml.