Late-onset deep surgical-site infection after posterior lumbar interbody fusion in a patient treated with tocilizumab; unusual changes in inflammatory markers

Long-Term Results of Anterior-Only Lumbar Interbody Fusions in Rheumatoid Arthritis Patients: Comparative Retrospective Cohort Study

OBJECTIVE

Rheumatoid arthritis (RA) is a risk factor of lumbar spine surgical failure. The interest of anterior lumbar fusion in this context remains unknown. This retrospective study aimed to compare the outcome of anterior-only fusions between RA patients and non-RA (NRA) patients to treat lumbar spine degenerative disorders.

METHODS

NRA and RA groups including anterior-only fusion were compared. Clinical data (Visual Analog Scale score axial back pain scale, the Oswestry Disability Index, and a questionnaire of satisfaction regarding the surgical result); radiologic data (bone fusion, sagittal balance analysis); and adverse events were assessed using repeated measure 1-way analysis of variance.

RESULTS

The mean follow-up was 9.5 years (95% confidence interval [7.1-12.2]) for the RA group (n = 13) and 9.4 years (95% confidence interval [8.7-10.3]) for the NRA group (n = 36). Anterior fusion improved clinical outcome without any effect of RA (Visual Analog Scale score axial back pain scale; P < 0.001/Oswestry Disability Index; P = 0.01). The presence of RA influenced neither the satisfaction as the regards the surgical result nor spine balance nor bone fusion. Context of RA increased the surgical revision rate (10 patients [76.9%] for RA group vs. 3 patients [8.8%] for the NRA group; P = 0.001) because of the occurrence of an adjacent segment disease needing surgical revision (P = 0.028), especially the occurrence of intervertebral frontal dislocation (P = 0.02).

CONCLUSIONS

As noticed for posterior-only fusion, the anterior lumbar approach in RA patients does not seem to avoid the occurrence of an adjacent segment disease.

Retrospective study to evaluate the clinical significance of a second rise in C-reactive protein level following instrumented spinal fusion surgery

BACKGROUND

This study aimed to identify the incidence and causes of a second rise in C-reactive protein (CRP) levels following spinal instrumentation surgery and to help determine how an abnormal CRP response should be interpreted and managed during postoperative care.

METHODS

The medical records of 948 patients who underwent instrumented spine fusion surgery and met the inclusion criteria were retrospectively reviewed to assess the frequency and causes of a second rise (SR) of CRP. A SR of CRP was defined when the CRP level after postoperative day 7 increased by more than 0.5 mg/dl from that at the previous time-point. The diagnostic cut-off value of CRP elevation for detection of surgical site infection (SSI) was determined. Cut-off values were analyzed using receiver operating characteristic (ROC) curves. Bayes' theorem was used to determine blood test posterior probabilities for SSI-positive cases using cutoff values of re-evaluated CRP levels.

RESULTS

SR of CRP occurred in 107 of the 948 patients. Of the patients with SR of CRP, 38 (35%) patients had developed SSI, 33 (31%) patients had causes other than SSI, and the remaining 36 patients had unidentified causes. Among the patients with SR, excluding those with causes other than SSI, the best diagnostic cut-off value of SR for detection of SSI was 3.04 mg/dl (area under the curve was 0.74). The posterior test probability was 84.4%.

CONCLUSIONS

For patients with SR of CRP, who had no causes other than SSI, an SR value of 3.04 mg/dl correlated with a high probability of developing SSI.

[Rheumatoid instability in the cervical spine : Diagnostic and therapeutic strategies]

BACKGROUND

The involvement of the cervical spine in rheumatoid arthritis (RA) continues to be of clinical importance even in this age of biologics. Pathophysiological changes begin with an isolated atlantoaxial subluxation and may progress to a complex craniocervical and subaxial instability. The onset of cervical myelopathy can occur at any time and leads to a deterioration of the prognosis for the patient.

THERAPY

Treatment of the rheumatoid cervical spine should be aimed at improvement of the symptoms and prevention of further progress of the disease. In the case of instability, this is only possible by surgical treatment. The increasing usage of biological agents has led to a change in the clinical picture of the cervical involvement in RA patients. There are fewer patients presenting with isolated atlantoaxial instability. In contrast, the number of patients with complex craniocervical and/or subaxial instabilities is increasing. Complex cervical instabilities may require a longer fusion from the occiput to the upper thoracic spine. Modern operative techniques make this complex surgery also possible in severely disabled patients with a high comorbidity.

Predictive value of post-operative neutrophil/lymphocyte count ratio for surgical site infection in patients following posterior lumbar spinal surgery

OBJECTIVE

Surgical site infection (SSI) is a common complication in patients following posterior lumbar spinal surgery. Various laboratory data such as laboratory parameters derived neutrophil/lymphocyte count ratio (NLR), have been applied for the prediction of SSI, but more studies are necessary to evaluate the significance of these indicators. Here, our study aims to investigate the predictive value of total white blood cells (WBCs), count and percentages of neutrophils and leukocytes, NLR, and C-reactive protein (CRP) for surgical site infection (SSI) in patients after posterior lumbar spinal surgery.

METHODS

A total of 293 patients who underwent posterior lumbar spinal surgery were enrolled in this study. Each patient's medical history was retrospectively reviewed, and patients were divided into the deep SSI group (n = 13) and the non-SSI group (n = 280). Laboratory data including total WBC, count and percentages of neutrophils and leukocytes, NLR at 1 week before the operation and the 4 and 7 days post-operation, and CRP at 4 and 7 days post-operation were analysed between the SSI and non-SSI groups. Moreover, predictive power and cut-off of NLR for SSI were determined by receiver operating characteristic curve (ROC) results.

RESULTS

Data revealed that the medians of NLR were markedly increased in the SSI group as compared to that in non-SSI group at 4 days (p = 0.011) and 7 days (p = 0.047) post-operation. Moreover, the neutrophil percentage was also dramatically increased in the SSI group at both 4 and 7 days post-operation (p = 0.010 and p = 0.030) respectively compared to the non-SSI group. However, no significant difference was observed between the groups 1 week before the operation. ROC results showed that NLR at 4 days (cut-off >5.19; sensitivity: 61.5%; specificity: 77.6%; AUC = 0.708) and 7 days (cut-off >3.85; sensitivity: 69.2%; specificity: 62.7%; AUC = 0.663) post-operation could significantly discriminate the SSI and non-SSI groups. Logistic regression analysis showed that NLR at both post-operative time points (OR = 1.218; p = 0.003 and OR = 1.296; p = 0.048) could be valuable predictors for SSI.

CONCLUSION

NLR at 4 and 7 days post-operation are valuable laboratory predictors for SSI in patients with posterior lumbar spinal surgery.

White Blood Cell Count and C-Reactive Protein Variations After Posterior Surgery With Intraoperative Radiotherapy for Spinal Metastasis

STUDY DESIGN

Retrospective case series.

OBJECTIVE

To evaluate the feasibility of blood test parameters [white blood cell (WBC) count and C-reactive protein (CRP)] for predicting and diagnosing postoperative infection after posterior surgery with intraoperative radiotherapy (IORT) for spinal metastasis.

SUMMARY OF BACKGROUND DATA

Posterior surgery with IORT is effective for treating spinal metastasis, as we previously reported. However, the procedure requires that the patient be transferred from the operating room to the irradiation room. In addition, the patient's general status is often poor, and the risk of postoperative infection is high.

MATERIALS AND METHODS

A total of 279 patients who underwent IORT for the treatment of spinal metastasis between August 2004 and June 2013 were included in this study. The WBC count (/10 μL) and CRP level (mg/dL) were recorded in all patients preoperatively and on alternative days for up to 7 days after surgery. We assessed the development of surgical-site infection (SSI) for up to 1 month after surgery.

RESULTS

SSI occurred in 41 patients (14.7%). The preoperative WBC count and CRP level did not differ between the infected and noninfected patients. The WBC counts on postoperative day (POD) 1 and POD 7 and the CRP levels on POD 7 were significantly higher in the infected patients (8.8 vs. 10.0, P=0.04; 6.1 vs. 8.8, P=0.002; 3.89 vs. 9.50, P<0.001). A receiver-operating characteristic curve analysis of the WBC count and CRP level for detecting SSI showed cutoff values of 9.6 (WBC count, POD 1), 6.5 (WBC count, POD 7), and 5.0 (CRP level, POD 7).

CONCLUSIONS

A high WBC count and CRP level on POD 7 may be used to predict or detect SSI. In particular, a CRP level of 5.0 mg/dL on POD 7 strongly suggests the future development of SSI (sensitivity: 78%, specificity: 74%).

[Low back pain in rheumatoid arthritis]

Low back pain (LBP) in patients with rheumatoid arthritis (RA) has so far been of little concern in clinical investigations. The main focus of scientific publications on spinal problems in RA was the cervical spine. In a recent study, we could demonstrate that LBP in RA patients leads to a significantly higher degree of disability and depression as well as to a reduction in quality of life compared to RA patients without LBP. If there is a specific reason for the additional symptom of LBP, such as spinal stenosis or segmental instability, surgical treatment may be indicated to improve disability and quality of life. For a successful outcome of spinal surgery it is important to address the specific aspects of RA patients, such as poor bone quality and the immunosuppressive effect of antirheumatic drug treatment. Whenever possible, minimally invasive surgical techniques should be used and the immunosuppressive medication should be stopped before surgery.

Impact of Delayed Chest Closure on Surgical Site Infection After Lung Transplantation

BACKGROUND

Delayed chest closure is an increasingly used approach in the management of bleeding and hemodynamic instability after lung transplantation. We sought to evaluate the impact of delayed chest closure on surgical site infection.

METHODS

We performed a single-center retrospective cohort study and included adult patients who received a lung transplant at our center between January 1, 2010, and July 31, 2014. We defined surgical site infection as a thoracotomy incision wound or pleural space infection. Follow-up was complete through 6 months after transplantation. We used logistic regression models to examine the impact of delayed chest closure on surgical site infection and to identify other potential risk factors.

RESULTS

During the study period, 67 of the 232 transplant procedures (29%) required delayed chest closure, and surgical site infection developed in 22 recipients (9%). Among the patients with surgical site infection, 18 experienced a wound infection, and 8 experienced a pleural space infection; 4 experienced concomitant wound and pleural space infection. Among the 67 who underwent delayed chest closure, 13 patients (19%) experienced a surgical site infection compared with 9 of the 165 patients (5%) who underwent primary closure (p = 0.001). In multivariate analysis, delayed chest closure was an independent risk factor for surgical site infection.

CONCLUSIONS

Although delayed chest closure may have an important role in the immediate management of recipients of a lung transplant, it is an independent risk factor for surgical site infection, and this is associated with increased morbidity.

Postoperative Surgical Infection After Spinal Surgery in Rheumatoid Arthritis

Individuals with rheumatoid arthritis are at higher risk for infection than the general population, and surgical site infection after spinal surgery in this population can result in clinically significant complications. The goal of this study was to identify risk factors for acute surgical site infection after spinal surgery in patients with rheumatoid arthritis who were treated with nonbiologic (conventional) disease-modifying antirheumatic drugs (DMARDs) alone or with biologic DMARDs. All patients treated with biologic agents were treated with nonbiologic agents as well. The authors performed a retrospective, single-center review of 47 consecutive patients with rheumatoid arthritis who underwent spinal surgery and had follow-up of 3 months or longer. The incidence of surgical site infection was examined, and multivariate logistic regression analysis was performed to test the association of surgical site infection with putative risk factors, including the use of biologic agents, methotrexate, and prednisolone, as well as the duration of rheumatoid arthritis, the presence of diabetes, patient age, length of surgery, and number of operative levels. After spinal surgery, 14.89% (7 of 47) of patients had surgical site infection. Use of methotrexate and/or prednisolone, patient age, diabetes, duration of rheumatoid arthritis, length of surgery, number of operative levels, and use of biologic DMARDs did not significantly increase the risk of infection associated with spinal surgery. All patients who had surgical site infection had undergone spinal surgery with instrumentation. The findings show that greater attention to preventing surgical site infection may be needed in patients with rheumatoid arthritis who undergo spinal surgery with instrumentation. To the authors' knowledge, this is the first study to show that the use of biologic agents did not increase the incidence of surgical site infection after spinal surgery in patients with rheumatoid arthritis. [Orthopedics. 2016; 39(3):e430-e433.].