Application of oblique lumbar interbody fusion for lumbar intervertebral pyogenic infection

Objective To investigate the safety, key techniques and clinical efficacy of OLIF (oblique lumbar interbody fusion) corridor combined with lumbar intervertebral debridement, fusion with two interbody and internal fixation for the treatment of single-level lumbar pyogenic spondylodiscitis. Methods From February 2016 to March 2017, data of 12 patients with single-level lumbar intervertebral pyogenic infection diagnosed in our hospital who had undergone oblique lumbar interbody fusion with two interbody and posterior pedicle screw fixation via Wiltse approach were retrospectively analyzed. Among them, there were 10 males and 2 females, aged from 49 to 79 years, with an average age of 65.4±9.5 years. The white blood cells (WBC), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were recorded and analyzed before operation and at the last follow-up. Lumbar pain was assessed by visual analogue acale (VAS), Oswestry disability index (ODI), and clinical efficacy was assessed by the MOS 36-item short-form health survey (SF-36) and Kirkaldy-Willis criteria. The hospitalization time, operation time, intraoperative blood loss, pathological reports, etiological results and complications were recorded. Disc height (DH), segmental angle (SA) and Lumbar Lordosis (LL) were measured before operation and at the last follow-up. The fusion time was recorded. Paired t-test and ANOVA was used for data analysis. Results All patients underwent surgery successfully, including 6 cases using two titanium meshes and 6 cases using two autologous tricortical iliac bones. Pathogenic culture was positive in 10 cases, with a positive rate of 83.3%, including 4 cases of streptococcus, 4 cases of Staphylococcus aureus, 1 case of Escherichia coli, and 1 case of Klebsiella pneumoniae. All patients were followed up for 16.1±5.1 months. At the last follow-up, WBC ([6.25±2.02] ×109/L) was lower than that before operation ([4.89±1.28] ×109/L), CRP (preoperation 58.73±52.56 mg/L vs postoperation 8.48±8.79 mg/L) and ESR (preoperation 51.88±19.04 mm/1 h vs postoperation 9.25±5.50 mm/1 h) were significantly lower (P< 0.01). The VAS score was preoperation 6.67±1.63 and postoperation 1.50±0.55, ODI score was preoperation 72.57%±3.41% and postoperation 18.00%±2.31%, and both were significantly lower postoperatively (P < 0.01). SF-36 score (preoperation 56.33±4.93 vs postoperation 73.73±5.86) was significantly higher (P< 0.01) respectively. The postoperative height of intervertebral space ([11.68±2.64] mm) was significantly higher than that before operation ([5.18±1.58] mm). The disc height at the last follow-up was (11.22±2.25) mm, and the loss rate was 1.89% compared with that of the immediate postoperatively; The postoperative lumbar lordosis angle (32.89°±14.52°) was significantly increased compared with that of the preoperative (24.16°±13.49°), and maintained well at the last follow-up (32.27°± 14.21°); The postoperative segmental angle (10.8°±8.51°) was significantly increased compared with that of the preoperative (5.81°±7.44°), and maintained well at the last follow-up (9.94°±7.87°). The fusion time ranged from 6 to 16 months, with an average of 9.2±3.5 months. The clinical efficacy was excellent in 10 cases (83.3%) and good in 2 cases (16.7%). The excellent and good rate was 100%. One case of pulmonary infection and pulmonary embolism occurred 2 days after operation, and recovered after use of antibiotics and anticoagulation treatment in ICU; one case of intramuscular venous thrombosis was found 1 day after operation, and recovered after anticoagulation treatment; no loosening of internal fixation was found, and no complications related to OLIF corridor occurred. Conclusion The treatment of single-level lumbar intervertebral pyogenic infection with OLIF corridor combined with lumbar intervertebral debridement, fusion with two interbody and internal fixation has the advantages of less blood loss, shorter operation time, more direct clearance of intervertebral space and left paravertebral focus, no disturbance of intraspinal canal and posterior structure, higher positive rate of etiology detection, shorter bedrest time and better restore of disc height and lumbar lordosis after operation. What’s more, the fusion rate is high and the clinical efficacy is satisfactory. Key words: Lumbar vertebrae; Infection; Spinal fusion