Surgical treatment of infections in lumbar vertebral fusion with cage and pedicle screw system / 中华骨科杂志

ABSTRACT

Objective:To investigate the effect of anterior or posterior debridement on infections of the lumbar vertebral fusion with cage and pedical screw system.Methods:A total of 10 cases (3 males and 7 females, age 49.80±13.29 years) with infections in the lumbar fusion device were admitted from January 2013 to December 2019. The cases were diagnosed with deep infections after the preview surgery at 10.80±13.24 months, including 10 cases with 12 cages infections and 8 cases with screw system infections. 7 cases were done with debridement and removal of the cages via the anterior approach. And another 3 cases underwent posterior debridement and removal of lumbar fusion cages. The changes in laboratory examination such as WBC count, ESR, CRP, visual analogue scale (VAS) and Oswestry Disability Index (ODI) score were compared preoperatively, 2 months and 6 months postoperatively.Results:No patients were lost in the follow-up. The average follow-up time periods is 16.30±5.10 months (range 9-24 months). There was no significant difference in WBC count between 2 and 6 months after surgery compared with preoperation ( F=0.855, P=0.436). The ESR, CRP, VAS and ODI scores decreased in 2 months and 6 months after sugery, which has significant differences compared preoperation ( P<0.05). The abnormal signals in the lambar vertebral showed a gradual fading trend in the postoperative MRI. The completely fading time was 5.00±1.33 months (range 3-7 months). One-stage bone grafting was performed in 6 cases with 8 spaces via anterior approach, 5 cases with 7 spaces showed the intervertebral fusion after postoperative with 6.80±2.28 months (range 4-10 months), 1 case wirh 1 space was not fused. One-stage bone grafting was performed in 2 cases via posterior approach: 1 case was fused after postoperative and the other patient was not, which due to bone graft area infection. Postoperative bone graft displacement occurred with 1 case and 1 case with L 5 nerve root pulling injury during the operation. Conclusion:The fusion cage can be removed by debridement via posterior approach, but it is difficult to done the completely debridement, which the main reason is the obstruction of the posterior nerve and bone structure. Posterior approach also have risks of infection recurrence and nerve root injury. Cage removal via anterior approach was relatively easy and debridement was thoroughly, which has the risk of injury of important adjacent vessels.