ABSTRACT
Objective:To investigate the clinical features and treatment strategies of infection after lumbar transpedicular dynamic stabilization.Methods:A total of 1 623 cases with lumbar transpedicular dynamic stabilization conducted from January 2010 to June 2020 were retrospectively analyzed, including 854 males and 769 females and aged 47.56±12.76 years old. There were 1 150 cases with Dynesys fixation, 235 cases with K-Rod, 181 cases with Isobar, 52 cases with Fule and 5 cases with Waveflex. The primary diseases were as following, 984 cases (60.63%) with lumbar disc herniation, 280 cases (17.25%) with lumbar spinal stenosis, 174 cases (10.72%) with lumbar spondylolisthesis, 98 cases (6.04%) with lumbar degenerative scoliosis and 87 cases (5.36%) with discogenic low back pain. Some baseline indicators, such as the overall incidence of infection, the age, gender, smoking, drinking, diagnosis, previous operation history, concomitant disease, the number of fenestration, the number of discectomy, the number of fixed segments, operation duration, blood loss, blood transfusion, the number of the dura mater rupture, postoperative infection duration from primary operation, inflammation indicators (leukocytes, neutrophils, C-reactive protein, erythrocyte sedimentation rate and procalcitonin) of the infected patients, were recorded. According to the time when the infection occurred, the cases were divided into the early infection group (within 3 months after surgery) and the late infection group (more than 3 months after surgery). The clinical indicators and treatment strategies were compared between the two groups.Results:The overall infection rate was 1.66% (27/1 623), including 2.17% (25/1 150) in Dynesys fixation, 1.92% (1/52) in Fule fixation and 0.55% (1/181) in Isobar fixation. The follow-up duration was 51.89±32.55 months. The number of fenestrations was 1(1, 2). The number of discectomy was 1(1, 2), and that of fixed segments was 2(1, 3). The operation duration was 186.30±81.33 minutes, with the blood loss 200 (200, 500) ml and the blood transfusion volume 0(0, 345) ml. There was 1 case of cerebrospinal fluid leakage in early infection group. Thirteen cases of pathogenic bacteria were identified, included 5 cases of Staphylococcus epidermidis, 2 cases of Staphylococcus aureus and 1 case each of Salmonella, Escherichia coli, Pseudomonas aeruginosa, Enterobacter aerogenes, Acinetobacter baumannii, and Streptococcus lactis. A total of 21 patients underwent secondary surgery, including 10 cases of debridement and suturing, 2 cases of internal fixation replacement and 9 cases of internal fixation removal. The other 4 cases underwent puncture and irrigation, while 2 cases received only antibiotic treatment. There were 16 cases with early infection and 11 cases with late infection. There were no significant differences between the two groups in the number of fenestrations, discectomy, operation duration, blood loss, and blood transfusion ( P>0.05). The inflammation indexes of early infection group were higher than those of late infection group with significant difference ( P<0.05), except for procalcitonin. The detection rates of pathogenic bacteria in early and late infection group were 62.5% (10/16) and 27.3% (3/11), respectively. The main infection sites in early infection group were the incision (50.0%, 8/16) and around the internal fixation (18.8%, 3/16). However, the main infection sites in late infection group were around the internal fixation (90.9%, 10/11). In the early infection group, the main treatments including debridement and suturing were conducted in 9 cases, puncturing in 2 cases and internal fixation replacement in 2 cases. In the late infection group, internal fixation removal was performed in 8 cases and puncturing in 2 cases. Conclusion:The overall infection rate after lumbar transpedicular dynamic stabilization was 1.66%. The incidence of early infection was 0.99%, while that of late infection was 0.68%. The incidence of Dynesys fixation was 2.17%. In early infection, the internal fixation could be retained through some treatments as debridement and internal fixation replacement. In most late infection cases, removal of the internal fixation could be helpful to control the infection.