The C-reactive protein for detection of early infections after lumbar microdiscectomy

Post-Discectomy Infection: A Critical Review and Suggestion of a Management Algorithm

Postoperative discitis (POD) accounts for 20% to 30% of all cases of pyogenic spondylodiscitis, while POD may be mis-or-under-diagnosed, due to the vague related symptomatology and the non-specific imaging findings. Most studies report infection rate of less than 1%, which increases with the addition of non-instrumented fusion to 2.4% to 6.2%. It remains controversial whether POD is caused by an aseptic or infectious process. Positive cultures are presented only in 42-73% of patients with Staphylococcus species being the most common invading organisms, while Staphylococcus aureus is isolated in almost 50% of cases. The onset of POD symptoms usually occurs at 2-4 weeks after an apparently uneventful operation. Back pain and muscle spasms are usually refractory to bed rest and analgesics. Magnetic Resonance Imaging (MRI) is the most sensitive and specific imaging diagnostic technique. Antimicrobial therapy depends on the results of tissue cultures, and along with bracing represents the mainstay of management. Surgical intervention is necessary in patients failing conservative treatment. For the majority of cases, extensive surgical debridement, antibiotic therapy, and orthosis immobilization are effective in eliminating the infection. According to this, we recommend an Algorithmic approach for the management of POD. Postoperative infections after spinal surgery pose a certain clinical challenge, and in most cases can be treated conservatively. Nevertheless, disability may be persistent, and surgery could be necessary. The purpose of this concise review is to describe the manifestation of post-discectomy infection, its pathogenesis and particularly a rational approach for its management.

Postoperative Serum C-Reactive Protein and Cerebrospinal Fluid Leakage after Endoscopic Transsphenoidal Surgery

Objective  Postoperative cerebrospinal fluid (CSF) leakage in endoscopic transsphenoidal surgery is a potential risk that requires immediate repair. We investigated the potential of common postoperative hematological examinations for diagnosing postoperative CSF leakage. Methods  We retrospectively studied 214 consecutive cases who underwent endoscopic transsphenoidal approach (ETSA; transsellar approach) or extended ETSA (E-ETSA). Patients with postoperative CSF leakage were defined the leak group (group L), and patients without were defined as the nonleak group (group N). Postoperative C-reactive protein (CRP) was compared between the ETSA and E-ETSA groups, and between the N and L groups. Results  The values of white blood cell count and CRP 1 to 7 days after surgery were significantly higher in the L group. Especially, CRP was clearly elevated in the L group ( p  < 0.001). The CRP value was higher in patients in the N group after E-ETSA than after ETSA ( p  < 0.001). CRP increased on the day after surgery but decreased gradually thereafter in patients after ETSA and in the N group. In contrast, CRP value tended to increase gradually after surgery in the L group. In particular, the CRP on the day before the CSF leak was confirmed was clearly higher than on the fifth to seventh days in the N group. Conclusion  Elevated CRP after endoscopic endonasal transsphenoidal surgery is a potential marker of CSF leakage.

Spondylodiscitis-a cohort analysis of its identification and management

PURPOSE

Discitis represents infection of the intervertebral disc and osteomyelitis of the adjacent end plates. Classically, patients present with fever and back pain. Varied presentations and lack of adherence to guidelines lead to great variation in its identification and management. The primary objective of this study was to conduct a cohort analysis, assessing the identification and management of discitis, in a busy secondary orthopaedic centre.

METHODS

A retrospective study was conducted, of cases diagnosed and treated for discitis, in a secondary orthopaedic department, within the UK from January 2017 to October 2019. During this time period, all patients who underwent magnetic resonance imaging (MRI) spine were identified. Patients with MRI-proven discitis were then added into the study.

RESULTS

A total of 152 MRIs showed radiographic features of discitis. Of these, only 38 had a clear clinical correlation. Back pain was the most common presenting complaint followed by fever. The commonest site of involvement was vertebral levels L5 and S1. All patients had baseline bloods, and most, but not all, had blood cultures taken. Staphylococcus aureus was the most frequently isolated, causative organism. The mainstay of treatment was intravenous flucloxacillin, with most patients requiring a minimum of six weeks.

CONCLUSION

Our study has helped define the population of patients presenting with discitis, in a busy secondary orthopedic center. Analyzing over two years of data has provided us with valuable insight into the most appropriate diagnostics and management for discitis.

Spinal Surgery and Subsequent ESR and WBC Changes Pattern: A Single Center Prospective Study

Objective

Postoperative inflammation and infections are common complications of spinal surgery and have similar symptoms. However, postoperative infection may lead to a poor outcome and must be differentiated from postoperative inflammation. The objective of this study is determine the changing pattern of postoperative ESR and WBC counts, and investigate the effects of different variables.

Methods

A total of 61 patients who underwent spinal surgery were enrolled in this prospective study. The erythrocyte sedimentation rate (ESR) and white blood cell (WBC) counts were measured the day before surgery and on 1st, 3rd, 5th, 7th, and 14th postoperative days.

Results

WBC counts increased on the 1st postoperative day in comparison with the preoperative day (p<0.001), and they gradually decreased until the preoperative value was reached on the 14th postoperative day (p=0.14). The ESR also increased postoperatively, reaching a peak on the 5th postoperative day in comparison with the preoperative day (p<0.001) and gradually decreased thereafter. However, on the 14th postoperative day, the ESR was significantly greater than the preoperative value (p<0.001). In addition, a significant positive correlation was observed between ESR and age, duration of surgery, intraoperative blood loss, and duration of anesthesia.

Conclusion

WBC count continued to rise and was the highest on the 1st postoperative day, after which it gradually decreased and attained normal values on the 14th postoperative day, while the ESR increased on the 1st postoperative day, reached the highest level in patients with and without simultaneous instrumentation on 7th and 5th postoperative days, respectively, and gradually decreased.

A Clinical Prediction Tool for MRI in Emergency Department Patients with Spinal Infection

Introduction

Patients with pyogenic spinal Infection (PSI) are often not diagnosed at their initial presentation, and diagnostic delay is associated with increased morbidity and medical-legal risk. We derived a decision tool to estimate the risk of spinal infection and inform magnetic resonance imaging (MRI) decisions.

Methods

We conducted a two-part prospective observational cohort study that collected variables from spine pain patients over a six-year derivation phase. We fit a multivariable regression model with logistic coefficients rounded to the nearest integer and used them for variable weighting in the final risk score. This score, SIRCH (spine infection risk calculation heuristic), uses four clinical variables to predict PSI. We calculated the statistical performance, MRI utilization, and model fit in the derivation phase. In the second phase we used the same protocol but enrolled only confirmed cases of spinal infection to assess the sensitivity of our prediction tool.

Results

In the derivation phase, we evaluated 134 non-PSI and 40 PSI patients; median age in years was 55.5 (interquartile range [IQR] 38–70 and 51.5 (42–59), respectively. We identified four predictors for our risk score: historical risk factors; fever; progressive neurological deficit; and C-reactive protein (CRP) ≥ 50 milligrams per liter (mg/L). At a threshold SIRCH score of ≥ 3, the predictive model’s sensitivity, specificity, and positive predictive value were, respectively, as follows: 100% (95% confidence interval [CI], 100–100%); 56% (95% CI, 48–64%), and 40% (95% CI, 36–46%). The area under the receiver operator curve was 0.877 (95% CI, 0.829–0.925). The SIRCH score at a threshold of ≥ 3 would prompt significantly fewer MRIs compared to using an elevated CRP (only 99/174 MRIs compared to 144/174 MRIs, P <0.001). In the second phase (49 patient disease-only cohort), the sensitivities of the SIRCH score and CRP use (laboratory standard cut-off 3.5 mg/L) were 92% (95% CI, 84–98%), and 98% (95% CI, 94–100%), respectively.

Conclusion

The SIRCH score provides a sensitive estimate of spinal infection risk and prompts fewer MRIs than elevated CRP (cut-off 3.5 mg/L) or clinician suspicion.

Serum C-reactive protein and WBC count in conservatively and operatively managed bacterial spondylodiscitis

PURPOSE

C-reactive protein (CRP) and white blood cell (WBC) count are routine blood chemistry parameters in monitoring infection. Little is known about the natural history of their serum levels in conservative and operative spondylodiscitis treatment.

METHODS

Pre- and postoperative serum levels of CRP and WBC count in 145 patients with spondylodiscitis were retrospectively assessed. One hundred and four patients were treated by debridement, spondylodesis, and an antibiotic regime, 41 only with a brace and antibiotics. The results of the surgical group were compared to 156 patients fused for degenerative disc disease (DDD).

RESULTS

Surgery had a significant effect on peak postoperative CRP levels. In surgically managed patients, CRP peaked at 2-3 days after surgery (spondylodiscitis: pre-OP: 90 mg/dl vs. post-OP days 2-3: 146 mg/dl; DDD: 9 mg/dl vs. 141 mg/dl; p < 0.001), followed by a sharp decline. Although values were higher for spondylodiscitis patients, dynamics of CRP values were similar in both groups. Nonoperative treatment showed a slower decline. Surgically managed spondylodiscitis showed a higher success rate in identifying bacteria. Specific antibiotic treatment led to a more predictable decline of CRP values. WBC did not show an interpretable profile.

CONCLUSION

CRP is a predictable serum parameter in patients with spondylodiscitis. WBC count is unspecific. Initial CRP increase after surgery is of little value in monitoring infection. A preoperative CRP value, and control once during the first 3 days after surgery is sufficient. Closer monitoring should then be continued. Should a decline not be observed, therapy needs to be scrutinized, antibiotic treatment reassessed, and concomitant infection contemplated.

Interleukin-6 as inflammatory marker of surgical site infection following spinal surgery

BACKGROUND

In order to elucidate whether serum inflammatory markers identify patients with local surgical site infection(SSI) as underlying disease for recurrent or new symptomatology following spine surgery, we evaluated the diagnostic potential of interleukin-6(IL-6) as a marker of SSI. The diagnostic significance of IL-6 was compared to the standard serum inflammatory markers C-reactive protein(CRP) and white blood cell count (WBCC).

METHOD

Ninety-eight consecutive patients with readmission due to recurrent or new symptomology after spinal surgery of degenerative spine disorders entered the study. Baseline patients' characteristics and the abovementioned inflammatory markers were collected, and arithmetical means with standard deviation, area under the curve (AUC), thresholds, sensitivity, specificity, positive(+)likelihood ratio (LR), and negative(-)LR with corresponding 95% confidence interval(95%CI) were calculated and correlated with presence or absence of SSI.

RESULTS

Nine patients suffered from a SSI, whereas the remaining 89 patients had a recurrent/adjacent-segment degenerative disorder without evidence of infection. The most significant parameter for diagnosing a SSI was serum IL-6 (cut-off value > 15.3 pg/ml, AUC = 0.954, SE = 85.7%, SP = 97.3%), followed by CRP (cut-off value = 0.8 mg/dl, AUC = 0.916, SE = 88.9%, SP = 84.5%) CONCLUSIONS: In the case of recurrent or new symptomatology following spinal surgery, serum IL-6 has the highest diagnostic potential for diagnosing spinal SSI.

C-reactive protein kinetics post elective cranial surgery. A prospective observational study

Introduction: Post cranial surgery readmission, largely caused by surgical site infection (SSI), is a marker of patient-care quality requiring comprehensive discharge planning. Currently, discharge assessment is based on clinical recovery and basic laboratory tests, including C-reactive protein (CRP). Although CRP kinetics have been examined postoperatively in a handful of papers, the validity of CRP as a standalone test to predict SSI is yet to be explored.Methods: A prospective observational study was performed on adult patients undergoing elective cranial surgery over a 3-month period. Laboratory data; CRP, white cell count (WCC), neutrophil cell count (NCC), and clinical data were assessed pre and post-operatively and were evaluated as predictors for safe discharge. Readmission rates within 1 month were recorded.Results: In this study, 68 patients were included. About 8.6% were readmitted due to SSI. A postoperativepeak in CRP was seen on day 2 with a value of 57 in the non-readmitted group, and 115 in the readmitted group. CRP dropped gradually to normal levels by day 5 in the non-readmitted group. A secondary CRP rise at day 5 was noted in the readmitted group with a sensitivity, specificity, and negative predictive value of 71%, 90%, and 96%, respectively. Interestingly, our ROC analysis indicates that a CRP value of less than 65 predicts safe discharge with a sensitivity of 86%, specificity of 89% and negative predictive value of 98% of safe discharge (area under the curve, AUC: 0.782). No significant difference in other inflammatory markers was found between both groups.Conclusions: CRP increases postoperatively for 4-5 d which could be a physiological response to surgery, however, prolonged elevation or a secondary increase in CRP may indicate an ongoing infection. Our data validate the potential use of CRP levels to predict SSI. A multicentre study is warranted to investigate the role of CRP in predicting SSI.

[Infections after reconstructive spinal interventions : How do I deal with them?]

BASICS

Postoperative surgical site infections of the spine have been described in up to 20% of patients and can result in serious consequences for the patient and substantial treatment costs. Typical bacteria often arise from skin or fecal flora. Various risk factors for infection have been described, including obesity, diabetes, high ASA scores, as well as intraoperative factors such as heavy blood loss, dural tears, or several revision procedures. Consequently, the prophylaxis with pre- and postoperative risk minimization is of particular importance.

TREATMENT

When an infection has developed, it is important to carry out early operative revision involving tissue debridement, lavage and acquiring microbiological samples for culture. If the infection presents early, the instrumentation can often be retained. Adjuvant measures such as negative pressure wound treatment may improve the outcome. In late-onset infections, due to the biofilm production on the instrument surface or in cases of implant loosening, one should attempt to remove the instrumentation, and in cases of instability replace it. This article deals with the current literature on the subject and provides an overview of the data with regard to peri- and postoperative infections.

Conservative Treatment of Spondylodiscitis: Possible Therapeutic Solution in Case of Failure of Standard Therapy

Introduction:

Spondylodiscitis (SD) is an uncommon disease but not rare, because it represents around 3–5% of all cases of osteomyelitis. Late diagnosis and/or inadequate treatment often cause irreversible damage to cause neurological deficit. Most require only conservative treatment, sometimes a surgical approach is required.

Aim:

The purpose of this study is to propose a conservative protocol to treat spondylodiscitis when the standard conservative treatment has failed. This alternative treatment has been for a long time at the Codivilla-Putti Institute.

Methods:

We performed a prospective cohort study of 192 consecutive patients who underwent paravertebral intramuscular injections of antibiotic associated with standard treatment at our Center from January 2010 to December 2015 with SD. Of this 192 patients we selected 98 who had already undergone standard antibiotic therapy at another hospital without resolution of the disease. All patients have performed our protocol that provides a total of 3 cycles, each of 3 weeks, repeated at approximately 5 weeks apart. For each patient we evaluated Erythrocyte Sedimentation Rate (ESR), C-Reactive Protein (CRP), White Blood Cells (WBC) indexes, SF36 and VAS Score at the beginning and at the end of the treatment.

Results:

At a mean follow up of 22 months (range 60-12), clinical healing was achieved in 87 patients (88,9%) of cases with significant reduction in back pain and functional limitation. The VAS Score and the SF36 were better at the end of treatment compared to previous “GOLD STANDARD” treatments in the previous hospitalization in another hospital. In most cases there were slightly reduced in inflammatory indexes.

Conclusion:

There are no studies in the literature demonstrating the effective efficacy of local infiltrative treatment with antibiotics, associated with standard treatment protocol. We believe that our protocol in treating SD, favors an early functional recovery, and be able to offer more chance of success than the standard treatment.

Postsurgical Spine: Techniques, Expected Imaging Findings, and Complications

Postsurgical spine imaging actually commences with the preoperative and perioperative imaging examinations that are performed before and during the patient's surgical procedure, respectively. It is in this context that postsurgical spine imaging examinations are best evaluated with a better appreciation of the changes, sometimes dramatic, that can occur following spine surgery. Careful follow-up is the rule in spine surgery, and these patients will have multiple imaging examinations over time. Some studies are performed immediately due to possible complications or exacerbation of pain symptoms, whereas others are used to assess the status of a fusion procedure. In any case it is prudent to always be aware of the overlap between the "normal" or expected imaging findings in the postoperative spine and potential pathologic processes that are developing at the postsurgical site. Additionally, a basic understanding of common spine surgical techniques and approaches is paramount toward rendering a thoughtful analysis. In this chapter, the authors discuss these imaging findings in the setting of the most commonly performed spine surgeries and emphasize the importance of active communication between the radiologist and spine surgeon.

Management of Early Deep Wound Infection After Thoracolumbar Instrumentation: Continuous Irrigation Suction System versus Vacuum-Assisted Closure System

STUDY DESIGN

A retrospective study.

OBJECTIVE

The aim of this study was to compare the clinical outcomes of continuous irrigation suction systems (CISS) or vacuum-assisted closure system (VACS) in early deep wound infection (DWI) after thoracolumbar instrumentation.

SUMMARY OF BACKGROUND DATA

DWI after thoracolumbar instrumentation is challenging and debridement followed by either CISS or VACS has been proven to be effective. So far, which one of the system has more advantages over the other remains unclear.

METHODS

Patients after thoracolumbar instrumentation were evaluated at our spine surgery center from 2005 to 2015. Patients who were diagnosed with early deep DWI after spinal instrumentation and treated by meticulous debridement in the operating room followed by either CISS or VACS were included. Detailed information was obtained from the medical records, including clinical features, results of laboratory examinations, medical therapies, and outcomes. A follow-up was conducted to observe whether recurrent spinal infection or other complications happened.

RESULTS

We identified 11 patients in the CISS group and 12 patients in the VACS group. There were no significant differences in terms of age, gender, follow-up duration, symptoms of infection, laboratory examinations, etc. The number of CISS or VACS replacement was 1.3 and 1.6, respectively, before wound healing (P > 0.05). And there were significant differences in terms of hospital stay and extra cost of infection treatment between the two groups. In the follow-up period, we observed sinus tract formation and low back pain in both groups and one patient in the VACS group died of pulmonary infection 4 years after the initial surgery.

CONCLUSION

Thorough debridement followed by CISS or VACS are comparable in treating early DWI after thoracolumbar instrumentation. The CISS treatment was statistically significant in comparison to the VACS treatment in terms of hospital stay and cost.

LEVEL OF EVIDENCE

4.

Management of Postoperative Discitis: A Review of 31 Patients

BACKGROUND

The aim of the study was to retrospectively evaluate the outcome of medical management of postoperative discitis (POD).

MATERIALS AND METHODS

A total of 31 patients treated for POD were included in the study. Clinical, radiological, and laboratory data of all patients were collected and evaluated. All patients were treated initially with bed rest and antibiotic therapy after radiological diagnosis. Surgical management was undertaken after failure of 4 weeks of conservative management. All cases were followed clinically with laboratory and radiological investigations.

RESULTS

Five cases failed to respond to medical management and were treated surgically with debridement and transpedicular fixation. All patients showed clinical recovery till the last follow-up.

CONCLUSION

Early diagnosis and proper management are the keys to successful outcome of postoperative spndylodiscitis. Surgical debridement and fusion are required when conservative treatment fails.

Preoperative and Postoperative Factors and Laboratory Values Predicting Outcome in Patients Undergoing Lumbar Fusion Surgery

OBJECTIVE

To determine whether complications in lumbar fusion surgery could be estimated from patient factors and perioperative laboratory values. In addition, risk scores for detection of patients prone to complications were defined.

METHODS

We retrospectively collected data of patients undergoing lumbar fusion surgery between 2013 and 2015. The patients were divided into group A (no complications) and group B (systemic and infectious complications within 30 days postoperatively). Patient-related factors and levels of perioperative laboratory values were compared between the groups and analyzed for possible impact on complications and length of stay (LOS) in the hospital.

RESULTS

Data of 132 consecutive patients (74 women [56.1%]; median age, 68.5 years) were analyzed. Postoperative complications occurred in 29.5%. Higher postoperative creatine kinase (CK) and C-reactive protein and lower postoperative hemoglobin and thrombocyte values, as well as higher differences between preoperative and postoperative CK, C-reactive protein, and hemoglobin values were associated with postoperative complications. Among others, the combinations of advanced age and elevated body mass index (P = 0.0062, odds ratio: 3.018), or advanced age, elevated body mass index, and postoperative CK >166 U/L (P = 0.0016, odds ratio: 3.637) revealed patients with a threefold risk for complications. The combination of advanced age, American Society of Anesthesiologists score >2, and preoperative hemoglobin <12.9 g/dL was associated with a LOS of 20.3 versus 11 days (P = 0.01).

CONCLUSIONS

Patients with postoperative complications and extended LOS seem to show significant differences in various perioperative laboratory values and patient factors. Perioperative risk assessments using cut-off values and risk scores may help identify patients prone to complications and extended resource use.

A threshold for concern? C-reactive protein levels following operatively managed neck of femur fractures can detect infectious complications with a simple formula

INTRODUCTION

C-reactive protein (CRP) rises in response to multiple stimuli, including surgical procedures and infections. Deviations from the predicted CRP response to a given procedure may be an early indication of a postoperative complication.

METHODS

Three hundred and fifty-four patients with an operatively managed neck of femur fracture admitted over a 1-year period to an NHS Hospital Trust were included. CRP values collected during the postoperative period were retrospectively examined, and objective evidence of postoperative complications was sought. Data analysis explored daily CRP thresholds that maximised sensitivity and specificity for the detection of patients with a postoperative complication.

RESULTS

From the 5th to the 30th postoperative day, a CRP value in excess of the threshold defined by the formula 500/d (where d represents the number of postoperative days) retrospectively detected patients with a postoperative complication with a sensitivity of 0.97 and specificity of 0.82. Patients with a CRP value above the 500/d threshold during this period had a significantly increased 30-day mortality (10.0% vs. 3.9%, RR=2.74, p=0.03).

CONCLUSION

Following operatively managed neck of femur fractures, a CRP value in excess of the threshold defined by the formula 500/d may indicate the presence of a postoperative complication and defines a group with increased mortality. In this context, a prompt wound review and septic screen could promote the early detection and management of infectious postoperative complications.

Efficacy of Antibiotics Sprayed into Surgical Site for Prevention of the Contamination in the Spinal Surgery

Study Design

Retrospective study.

Purpose

To evaluate the effect of intraoperative wound application of vancomycin on preventing surgical wound contamination during instrumented lumbar spinal surgery.

Overview of Literature

Postoperative infection is the one of the most devastating complications of lumbar surgery. There are a few reports showing the benefits of intraoperative wound application of vancomycin during spinal surgery. However, there is no report about the effectiveness of local vancomycin instillation in prevention of surgical wound contamination.

Methods

Eighty-six patients underwent instrumented lumbar spinal surgery. Mean patient age was 65.19 years (range, 23-83 years). There were 67 females and 19 males. During surgery, vancomycin powder was applied into the surgical site before closure in 43 patients (antibiotic group) and vancomycin powder was not applied into the surgical site before closure in 43 patients (control group). The tip of the surgical drain was cultured to evaluate surgical wound contamination. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were measured on the first, third, seventh, and fourteenth day after the operation.

Results

We found two patients with a positive culture from the tip of surgical drains in the antibiotic group, and one patient with a positive culture from the tip of the surgical drain in the control group. Postoperative ESR and CRP levels did not show significant differences between the two groups. On the third postoperative day, ESR in patients of the antibiotic group was more significantly decreased than that in patients of the control group, while CRP level did not show a significant difference between the two groups.

Conclusions

There was no evidence to suggest that intraoperative vancomycin application is effective in decreasing the risk of postoperative wound infection after instrumented posterior lumbar fusion surgery.

A Retrospective Analysis of the Management of Postoperative Discitis: A Single Institutional Experience

Study Design

Retrospective study.

Purpose

The aim of the study was to study the impact and outcome of conservative management and surgical intervention in cases of postoperative discitis.

Overview of Literature

Postoperative discitis is a rare but often misdiagnosed cause of failed back syndrome. There is paucity of literature regarding management guidelines of postoperative discitis.

Methods

The study was carried out over a period of 6 years. Eighteen patients with postoperative discitis were included in the study.

Results

Conservative management with antibiotics, analgesics and bed rest were started in all the study cases. Posterior transpedicular fixation after re-exploration debridement and curettage of disc space granulation tissue was conducted in five patients in whom conservative management failed.

Conclusions

Early diagnosis and appropriate management is the key to effective treatment of postoperative discitis. Conservative management leads to excellent results in majority of cases. Surgical intervention with posterior interbody fusion and debridement is helpful when conservative treatment fails.

Sequential Changes of Plasma C-Reactive Protein, Erythrocyte Sedimentation Rate and White Blood Cell Count in Spine Surgery : Comparison between Lumbar Open Discectomy and Posterior Lumbar Interbody Fusion

Objective

C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) are often utilized to evaluate for postoperative infection. Abnormal values may be detected after surgery even in case of non-infection because of muscle injury, transfusion, which disturbed prompt perioperative management. The purpose of this study was to evaluate and compare the perioperative CRP, ESR, and white blood cell (WBC) counts after spine surgery, which was proved to be non-infection.

Methods

Twenty patients of lumbar open discectomy (LOD) and 20 patients of posterior lumbar interbody fusion (PLIF) were enrolled in this study. Preoperative and postoperative prophylactic antibiotics were administered routinely for 7 days. Blood samples were obtained one day before surgery and postoperative day (POD) 1, POD3, and POD7. Using repeated measures ANOVA, changes in effect measures over time and between groups over time were assessed. All data analysis was conducted using SAS v.9.1.

Results

Changes in CRP, within treatment groups over time and between treatment groups over time were both statistically significant F(3,120)=5.05, p=0.003 and F(1,39)=7.46, p=0.01, respectively. Most dramatic changes were decreases in the LOD group on POD3 and POD7. Changes in ESR, within treatment groups over time and between treatment groups over time were also found to be statistically significant, F(3,120)=6.67, p=0.0003 and F(1,39)=3.99, p=0.01, respectively. Changes in WBC values also were be statistically significant within groups over time, F(3,120)=40.52, p<0.001, however, no significant difference was found in between groups WBC levels over time, F(1,39)=0.02, p=0.89.

Conclusion

We found that, dramatic decrease of CRP was detected on POD3 and POD7 in LOD group of non-infection and dramatic increase of ESR on POD3 and POD7 in PLIF group of non-infection. We also assumed that CRP would be more effective and sensitive parameter especially in LOD than PLIF for early detection of infectious complications. Awareness of the typical pattern of CRP, ESR, and WBC may help to evaluate the early postoperative course.

Diagnostic usefulness of white blood cell and absolute neutrophil count for postoperative infection after anterior cervical discectomy and fusion using allograft and demineralized bone matrix

Study Design

Prospective study.

Purpose

We investigated normative temporal levels of white blood cell (WBC) and absolute neutrophil count (ANC) in uncomplicated anterior cervical discectomy and fusion (ACDF) using allograft and demineralized bone matrix (DBM).

Overview of Literature

No study has investigated the diagnostic usefulness of WBC and ANC for postoperative infection following ACDF using allograft and DBM.

Methods

Blood samples of 85 patients, who underwent one or two-level ACDF, were obtained and evaluated before surgery and on the first, third, fifth, seventh, fourteenth, thirtieth, and ninetieth postoperative days. No infection was found in all patients for at least one year follow-up period.

Results

Mean WBC and ANC values increased significantly and reached peak levels on the first postoperative day. The peaked levels rapidly decreased but still remained elevated above the preoperative levels on the third postoperative day. The levels returned close to the preoperative levels on the fifth postoperative day. The mean WBC and ANC values did not get out of their normal reference ranges throughout the follow-up periods. One-level and two-level ACDF exhibited a similar course of postoperative changes in WBC and ANC values and no significant difference in mean levels of WBC and ANC throughout the follow-up periods.

Conclusions

Uncomplicated ACDF using allograft and DBM showed normal values of WBC and ANC during the early postoperative period. Therefore, significant abnormal values of WBC and ANC at an early postoperative period suggest the possibility of the development of acute postoperative infection after ACDF using allograft and DBM.

Transforaminal percutaneous endoscopic lumbar discectomy: technical tips to prevent complications

Transforaminal percutaneous endoscopic lumbar discectomy is regarded as an effective alternative to open discectomy. Remarkable technical evolution now enables selective endoscopic removal of an epidurally extruded disc fragment. As a result, the surgical indications for this technique are becoming broader. However, as the use of endoscopic techniques increases in spinal procedures, related complications emerge as important problems. These include postoperative dysesthesia, dural tears, hematoma, infection and visceral injury. There are several technical guidelines to increase the effectiveness of endoscopic techniques and prevent complications. Initial landing should be as close to the target as possible. Complete herniotomy after thorough release of annular anchorage is a key to success. The definitive end point of the procedure is free mobilization of neural tissues, not direct exposure of neural tissues.

Spondylodiscitis after Cervical Nucleoplasty without Any Abnormal Laboratory Findings

Infective spondylodiscitis is a rare complication that can occur after interventional spinal procedures, of which symptoms are usually back pain and fever. Early diagnosis of infective spondylodiscitis is critical to start antibiotics and to improve prognosis. Laboratory examinations including complet blood cell count (CBC), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) are conventional tools for the early detection of infectious spondylitis. However, we experienced infective spondylodiscitis after cervical nucleoplasty which did not display any laboratory abnormalities, but was diagnosed through an MRI. A patient with cervical disc herniation received nucleoplasty at C5/6 and C6/7. One month later, the patient complained of aggravated pain. There were neither signs of chill nor fever, and the laboratory results appeared normal. However, the MRI findings were compatible with infectious spondylodiscitis at the nucleoplasty site. In conclusion, infectious spondylodiscitis can develop after cervical nucleoplasty without any laboratory abnormalities. Therefore, an MRI should be taken when there is a clinical suspicion for infection in order to not miss complications after interventional procedures, even if the laboratory findings are normal.

Does surgical technique affect the incidence of spondylodiscitis post-lumbar microdiscectomy? A retrospective analysis of 3063 patients

STUDY DESIGN

Retrospective audit in a single center during a period of 7 years operated by 3 groups of surgeons after 3 different surgical techniques.

OBJECTIVE

Our study aimed to determine whether surgical technique had any influence on the incidence of spondylodiscitis in patients undergoing lumbar microdiscectomy and to compare this with published rate of incidence of spondylodiscitis.

SUMMARY OF BACKGROUND DATA

The incidence of spondylodiscitis post-lumbar microdiscectomy ranges from 0.2% to 15%. There is limited evidence to compare different techniques and the incidence of spondylodiscitis.

METHODS

A total of 3063 patients were analyzed from 2005 to 2011 for discitis postoperatively. The first group followed a standard microdiscectomy technique, the second group used antiseptic (Savlon; Novartis Consumer Health UK Limited, Surrey, UK) irrigation at the end of the procedure to irrigate the disc space, and the third group followed standard microdiscectomy along with usage of a separate disc instruments when discectomy was performed. The number of patients operated in the individual groups was 559, 1122, and 1382.

RESULTS

The total number of patients who had postoperative discitis was 3 (0.10%), with a range of 0.07% to 0.18%. There was 1 case of discitis in each group. The incidence of spondylodiscitis in groups A, B, and C were 0.18%, 0.09%, and 0.07%, respectively.

CONCLUSION

This study concluded that different techniques used for lumbar microdiscectomy revealed that standard microsurgical technique with usage of antiseptic irrigation for the disc space and usage of separate disc instruments had lesser incidence of spondylodiscitis in comparison with standard microdiscectomy. The overall incidence of postoperative discitis remains less in our series. So far, to our knowledge, this report involves the largest number of patients studied to determine the incidence of discitis in patients undergoing lumbar microdiscectomy.

LEVEL OF EVIDENCE

3.

Postoperative changes of early-phase inflammatory indices after uncomplicated anterior cervical discectomy and fusion using allograft and demineralised bone matrix

PURPOSES

We investigated sequential levels of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) in uncomplicated ACDF (anterior cervical discectomy and fusion) using allograft and DBM (demineralised bone matrix) for primary cervical spondylosis and/or disc herniation. To our knowledge, there has been no study to investigate the diagnostic value of CRP and ESR for postoperative infection in ACDF using allograft and DBM.

METHODS

Blood samples of 85 patients, who underwent one- (n = 51) or two-level (n = 34) ACDF, were obtained and evaluated before surgery and on the first, third, fifth, seventh, 14th, 30th, and 90th postoperative days. No infection was found in any patient for at least one year follow-up period.

RESULTS

Mean CRP value increased significantly on the first postoperative day and reached a peak on the third postoperative day. The peak level rapidly decreased but remained elevated on the fifth, seventh, and 14th postoperative days. Mean ESR value increased significantly and reached a peak on the third postoperative day. The peak level gradually decreased but remained elevated on the fifth and seventh postoperative days. One- and two-level ACDF exhibited similar postoperative changes in CRP and ESR values and no significant difference in mean levels of CRP and ESR throughout the follow-up periods.

CONCLUSIONS

This study demonstrates that uncomplicated ACDF using allograft and DBM showed significant abnormal values of CRP and ESR during the early postoperative period. This result suggests that abnormal values of CRP and ESR in the early postoperative period do not indicate acute postoperative infection after ACDF using allograft and DBM. Straying from the normal course, such as a second rise or a failure to decrease, of CRP and ESR is more important to signpost acute postoperative infection in ACDF using allograft and DBM.

Spondylodiscitis: standards of current treatment

BACKGROUND

Spinal infections are an important clinical problem that often require aggressive medical therapy, and sometimes even surgery. Known risk factors are advanced age, diabetes mellitus, rheumatoid arthritis, immunosuppression, alcoholism, long-term steroid use, concomitant infections, poly-trauma, malignant tumor, and previous surgery or invasive procedures (discography, chemonucleolysis, and surgical procedures involving or adjacent to the intervertebral disc space). The most common level of involvement is at the lumbar spine, followed by the thoracic, cervical and sacral levels: lesions at the thoracic spine tend to lead more frequently to neurological symptoms.

OBJECTIVE

The aim of the current paper is to describe current evidence-based standards of therapy in the management of SD by emphasizing pharmacological therapy and principles and indications for bracing and surgery.

METHODS

A PubMed and Google Scholar search using various forms and combinations of the key words: spondylodiscitis, spine, infection, therapy, surgery, radiology, treatment. Reference citations from publications identified in the literature search were reviewed. Publications highlighted in this article were extracted based on relevancy to established, putative, and emerging diagnostic and therapeutic standards, either conservative (antibiotic therapy and bracing) or surgical.

FINDINGS

To date, conservative therapy, based on targeted antibiotic therapy plus bracing, represents the mainstay in the management of SD. Proper diagnosis and tailored therapy can improve clinical results and decrease the chance of failure. Surgery should be an option only for patients with complications of this disease, namely deformity, neural compression and neurological compromise. Current standards in the setting of SD are continuously evolving, as can be seen in the recent advances in the field of radiological diagnostics, and the use of growth factors and cell-therapy strategies to promote infection eradication and bone healing after surgery.

Evaluation of the postoperative lumbar spine

Given the prevalence of low back pain, surgical interventions on the lumbar spine are becoming more common. Among the many surgical procedures available for these interventions, the most common are laminectomy and discectomy. In 10 to 40% of patients who undergo surgical interventions on the lumbar spine, low back pain is not completely alleviated or it recurs, and these cases fall into the category of « failed back surgery syndrome ». This syndrome can have many different causes and multiple factors are often involved. It is important not to confuse the normal postoperative findings with those specific to failed back surgery syndrome. Deciding which imaging technique to use will depend on the type of surgical intervention, whether metallic orthopedic material was used, and the clinical suspicion. It is essential to know the advantages and limitations of the available imaging techniques to ensure the optimal evaluation of these patients, especially after interventions carried out with instrumentation to minimize the artifacts due to these materials.

A review of epidural catheter-related infections

Spinal drug delivery is a generally safe and effective therapy for the treatment of both acute and chronic pain. However, it can be occasionally associated with significant complications, including neurologic injury, as a result of bleeding and infection in a confined space. This article focuses on risk factors for developing epidural catheter-related infections as well as strategies to minimize risks. Additionally, the diagnosis and management of epidural catheter-related infections, both superficial and deep, are discussed.

Infections in the operated spine: update on risk management and therapeutic strategies

Among the possible risks of spine surgery, surgical site infection (SSI) is far from negligible. Incidence is higher than in other locomotor system procedures, with more severe local and general impact. Certain broad guidelines can be formulated. The risk of SSI should be taken into account in the choice of treatment options discussed with the patient. Antibiotic prophylaxis, surgical prevention of iatrogenic infection and an SSI surveillance protocol should be implemented. SSI should be suspected in case of any abnormality in postoperative course, and biological and imaging (MRI or CT) measures should be taken. Local sampling for bacteriological identification is mandatory. Treatment strategy should ideally be discussed in a multidisciplinary coordination meeting, and adapted in the light of local bacterial ecology and resistance data. The information provided to the patient should be transparent and adapted to the patient's individual context.

LEVEL OF EVIDENCE

Level V.

CRP and leukocyte-count after lumbar spine surgery: fusion vs. nucleotomy

BACKGROUND

Despite the fact that C-reactive protein (CRP) levels and white blood cell (WBC) count are routine blood chemistry parameters for the early assessment of wound infection after surgical procedures, little is known about the natural history of their serum values after major and minimally invasive spinal procedures.

METHODS

Pre- and postoperative CRP serum levels and WBC count in 347 patients were retrospectively assessed after complication-free, single-level open posterior lumbar interlaminar fusion (PLIF) (n = 150) for disc degeneration and spinal stenosis and endoscopically assisted lumbar discectomy (n = 197) for herniated lumbar disc. Confounding variables such as overweight, ASA classification, arterial hypertension, diabetes mellitus, and perioperative antibiotics were recorded to evaluate their influence on the kinetics of CRP values and WBC count postoperatively.

RESULTS

In both procedures, CRP peaked 2-3 days after surgery. The maximum CRP level was significantly higher after fusion: mean 127 (SD 57) (p < 0.001). A rapid fall in CRP within 4-6 days was observed for both groups, with almost normal values being reached after 14 days. Only BMI > 25 and long duration of surgery were associated with higher peak CRP values. WBC count did not show a typical and therefore interpretable profile.

CONCLUSION

CRP is a predictable and responsive serum parameter in postoperative monitoring of inflammatory responses in patients undergoing spine surgery, whereas WBC kinetics is unspecific. We suggest that CRP could be measured on the day before surgery, on day 2 or 3 after surgery, and also between days 4 and 6, to aid in early detection of infectious complications.

Comparison of postoperative values for C-reactive protein in minimally invasive and open lumbar spinal fusion surgery

Background:

A major purported benefit of minimally-invasive spinal surgery (MIS) technique is less disruption of paraspinal soft tissues, but there is little quantifiable evidence of this in medical literature. Postoperative C-reactive protein (CRP) levels been shown to become more significantly elevated with larger surgical procedures, and this may allow for more measurable appreciation of any benefits of MIS verses open spinal surgery.

Methods:

CRP values were measured prior to and at multiple time points following surgery in patients undergoing posterior spinal fusion using both open and minimally invasive techniques.

Results:

Peak postoperative CRP was significantly lower in the 35 single-level minimally invasive procedures compared with the 11 single-level open procedures (13.5 vs. 21.3, P <0.01) and lower in the 12 two-level minimally invasive surgeries compared with 16 two-level open procedures (20.5 vs. 31.8, P <0.01).

Conclusions:

MIS lumbar fusion is associated with a lower peak in postoperative CRP compared with open surgery. This appears to support the notion that minimally invasive spine surgery technique leads to a measurable reduction in paraspinal soft tissue destruction mediated inflammation in the immediate postoperative period.

Treatment of infections of the spine

Spinal infection may involve the vertebrae, the intervertebral discs, and the adjacent intraspinal and paraspinal soft tissues. It often starts with subtle and insidious clinical signs and symptoms and may development to a debilitating and even life threatening disease. Spinal infections occur with increasing incidence and are nowadays a disease of everyday's practice for physicians treating spinal disorders. Traditionally, conservative treatment consisting of antibiosis and immobilisation is considered the first tier therapy. However, due to a considerably high rate of vertebral column instability or neurological impairment caused by the infected tissue, comprehensive experience with surgical measures have been acquired over the last decades. Thanks to tremendous improvements of surgical implants and techniques, surgical treatment has already begun to challenge conservative treatment to eventually become the first tier therapy for spinal infections in the future. This review seeks to give an overview of epidemiology, pathogenesis, diagnostic evaluation, and current nonsurgical and surgical therapy of spinal infections on the basis of the existing literature, which consists largely of retrospectively acquired data of single-centre experience with sample sizes of less than 100 patients treated with individually defined indications and treatment algorithms, and followed with various outcome parameters.

Surgical site infection in spinal surgery: detection and management based on serial C-reactive protein measurements

OBJECT

C-reactive protein (CRP) is a well-known sensitive laboratory parameter that shows an increase within 6 hours after the onset of bacterial infection. In relation to surgery, a normal CRP response is a rapid increase followed by a gradual reduction, eventually returning to the normal range. The goal of this study was to determine the diagnostic significance of CRP as a detector for early onset surgical site infection in spinal surgery and to discuss effective medical treatment through clinical interpretation and application of the measured CRP values.

METHODS

A prospective study was performed in 348 consecutive cases involving patients who underwent spinal surgery under general anesthesia between February and September 2008. Blood samples were obtained preoperatively and on postoperative Days 1, 3, and 5 in patients undergoing single-level decompression surgery. An additional blood specimen was obtained at postoperative Day 7 in patients requiring more extensive surgeries. Recorded laboratory results were compared with the patients' clinical course to determine the diagnostic significance of CRP. All of the patients received intravenous prophylactic antibiotic therapy. Once an abnormal response of CRP, indicated by a tendency toward continuous elevation, was noted on Day 5 or Day 7, the prophylactic antibiotics were replaced with another regimen and administration was resumed along with careful observation for signs of surgical site infection.

RESULTS

Monitoring of CRP revealed a characteristic increase and decrease pattern in 332 of 348 patients (95.4%) showing a normal clinical course with regard to early infectious complications. The mean measured CRP (reference range < 4 mg/L) averaged 14.9 +/- 20.3 mg/L on Day 1, 15.4 +/- 25.1 mg/L on Day 3, and 7.9 +/- 13.3 mg/L on Day 5. In contrast, there were 16 cases (4.6%) of abnormal CRP responses resulting in the resumption of intravenous antibiotic treatment, which included a second rise (in 12 cases) and a steady rise (in 4) in the CRP value. Five (1.4%) of 16 patients experienced infectious complications related to spinal surgery. Three patients (0.9%) received long-term antibiotic therapy for 4-6 weeks; however, all patients recovered with medical treatment alone and did not experience gross wound disruption or subsequent discitis. As a predictor for early wound infection, the sensitivity, specificity, positive predictive value, and negative predictive value for abnormal CRP responses were calculated as 100%, 96.8%, 31.3%, and 100%, respectively.

CONCLUSIONS

The above results demonstrate that CRP screening is a simple and reliable test for the detection of early infectious complications after spinal surgery. Close observation and appropriate medical management should be performed in a timely fashion when abnormal CRP responses are observed at 5 or 7 days after surgery.

Delayed diagnosis of tuberculous spondylitis masked by concomitant methicillin resistant Staphylococcus aureus infection

We present a case of tuberculous spondylitis in which diagnosis was masked by a concomitant pyogenic infection. The patient had undergone percutaneous needle aspiration of an abscess in the cavity of the psoas muscle. Early results from the culture regimen showed isolation of methicillin-resistant Staphylococcus aureus. After eight weeks, mycobacterium tuberculosis was grown at regimen which was cultured at the same site. Initial isolation of pyogenic bacteria, considered to be highly virulent organisms, led to delayed diagnosis and treatment of the tuberculosis.

Use of C-reactive protein after spinal surgery: comparison with erythrocyte sedimentation rate as predictor of early postoperative infectious complications

STUDY DESIGN

This is a prospective observational study of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) in a cohort of patients undergoing spinal surgery.

OBJECTIVE

We sought to characterize the normal kinetics of ESR and CRP after spinal surgery and compare their usefulness as predictors of infectious complications in the early postoperative period.

SUMMARY OF BACKGROUND DATA

ESR and CRP are nonspecific markers of inflammation used to evaluate postoperative infection. CRP is a quantitative test that exhibits predictable kinetics consisting of a postoperative rise and a peak followed by a decrease toward the normal value. Deviation from normal kinetics may be an indicator of infection.

METHODS

ESR and CRP were collected before surgery and daily after surgery in consecutive patients. All infectious complications were recorded.

RESULTS

One hundred forty-nine patients met inclusion criteria. Infectious complications occurred in 20 patients. A postoperative peak, which is necessary to apply the test, was observed in 78% of patients for CRP and 48% for ESR. Multiple linear regression analysis revealed preoperative CRP, number of levels, and lumbar region as significant predictors of greater CRP peak value (r = 0.435, P = 0.001). After the peak, CRP showed an exponential decrease with a half-life of 2.6 days (r = 0.701, P < 0.001). No trend could be determined for ESR. A second rise or failure to decrease as expected had a sensitivity, specificity, positive predictive value, and negative predictive value of 82%, 48%, 41%, and 86% for infectious complications, respectively. Of 8 cases of deep wound infection, 7 exhibited substantial deviations from expected CRP values.

CONCLUSION

CRP is more applicable, predictable, and responsive in the early postoperative period compared with ESR. The postoperative kinetics of CRP derived in this study seems to be conserved regardless of operation, magnitude, or region. Knowledge of the kinetics allows assessment of the degree of difference between actual and expected values. Using a second rise or failure to decrease as expected for CRP is sensitive for infection. A negative test is reassuring that infection is unlikely.

Postoperative spinal wound infections and postprocedural diskitis

BACKGROUND/OBJECTIVE

Postprocedural infections are a significant cause of morbidity after spinal interventions.

METHODS

Literature review. An extensive literature review was conducted on postprocedural spinal infections. Relevant articles were reviewed in detail and additional case images were included.

RESULTS

Clinical findings, laboratory markers, and imaging modalities play important roles in the detection of postprocedural spinal infections. Treatment may range from biopsy and antibiotics to multiple operations with complex strategies for soft tissue management.

CONCLUSIONS

Early detection and aggressive treatment are paramount in managing postprocedural spinal infections and limiting their long-term sequelae.

[Postoperative syndrome after spine surgery]

Postoperative syndrome after spine surgery, i.e., symptoms or syndromes caused by complications or procedure-related consequences, is gaining more and more importance. Due to great improvements concerning imaging and operative techniques (microsurgery, instrumentation) the total number of spinal surgeries as well as their related complications are increasing. Procedure-related postoperative complications including neurological deficit syndromes can occur acutely or at a later date. Concerning imaging techniques for postoperative evaluation after spinal surgery there are several modalities available. Their indications depend on complex factors including initial pathology the surgery was performed for, kind of surgical technique (surgical approach, instrumentation), anatomy of the patient as well as the time between onset of symptoms and surgery. In cases of ambiguous findings, the combination of different imaging techniques can be instrumental.

Serum C-reactive protein levels correlate with clinical response in patients treated with antibiotics for wound infections after spinal surgery

BACKGROUND CONTEXT

C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) have been used to diagnose postoperative infections after spinal surgery. However, it has not been demonstrated if resolution of the signs and symptoms of postoperative spinal wound infections in patients who are being treated with intravenous antibiotics correlates with these markers.

PURPOSE

The objective of this study was to determine if improvement of the signs and symptoms of postoperative wound infection after spinal surgery correlates with a decrease in serum CRP and ESR while intravenous antibiotics are administered.

STUDY DESIGN

Retrospective review.

PATIENT SAMPLE

The study consisted of 21 patients (mean age 63.8 years; 13 female, 8 male) with postoperative wound infections after spinal surgery. They were studied for a minimum of 20 weeks.

OUTCOME MEASURES

CRP and ESR were measured at the time of diagnosis and at serial time-points.

METHODS

All patients received intravenous antibiotic therapy for 6-8 weeks. Patients were monitored for clinical signs and symptoms of infection such as fever, drainage, erythema, or a need for continued wound packing at 4, 7, and 20 weeks after being diagnosed with a wound infection.

RESULTS

The average CRP for all 21 patients at time of diagnosis was 11.7+/-9.0 mg/dL (range 1.2 to 37.8 mg/dL). At the 4-week time-point, 16 patients ("early responders") showed clinical improvement with no fevers, no wound drainage, no erythema, and no need for wound packing. The average CRP of this group at the 4-week time-point decreased to 0.3+/-0.5 mg/dL. In contrast, at the 4-week time-point five patients ("late responders") still had signs and symptoms of infection (2 with continuing drainage requiring wound packing; 1 with vertebral osteomyelitis requiring irrigation and debridement; 2 with erythema without fevers). The average CRP for this group was still elevated at the 4-week time-point at 7.3+/-3.5 mg/dL. The CRP value difference was statistically significant between the two groups (p<.05). As treatment continued, at the 20-week time-point the average CRP of the late responders gradually decreased to 0.8+/-0.8 mg/dL, which was not statistically different from that of the early responders (average CRP=0.6+/-1.1 mg/dL). All 21 patients had resolution of infection at the 20-week time-point. The ESR did not correlate well with clinical improvement. At time of diagnosis, the ESR of both early responders (average=57.6+/-27.6 mm/hr) and late responders (average=64.0+/-21.9 mm/hr) was elevated. It remained elevated for both groups from the beginning of the study to the end at all time-points. The final ESR at the 20-week time-point was not different between the early responders and late responders (average=27.6+/-22.3 mm/hr vs. 31.0+/-2.6 mm/hr, respectively; p>.05).

CONCLUSIONS

Our data suggest that CRP may be of value in following the treatment response to antibiotics in wound infections after spinal surgery. The ESR can remain elevated in the presence of a normal CRP despite a resolution of clinical signs and symptoms of postoperative wound infection.

Clinical assessment and medical treatment of spine infections

Spinal infections affect the vertebral bodies, the intervertebral disks, the spinal canal, and the paravertebral soft tissues and structures. A delay in diagnosis can result in spine deformity, substantial neurologic complications, and even death. Because of this, a high level of awareness is required by physicians in order to diagnose infections of the spine promptly. Advances in medical microbiologic testing and newer imaging methods have contributed considerably to the medical treatment of these infections. Through careful followup, less invasive approaches orchestrated by a multidisciplinary team that includes a spine surgeon, an infectious diseases specialist, and a neuroradiologist may be sufficient to treat patients with these infections. Research done through multidisciplinary collaborations will further advance our knowledge for the successful treatment of spinal infections.

LEVEL OF EVIDENCE

Level V (expert opinion). Please see the Guidelines for Authors for a complete description of levels of evidence.

General principles in the medical and surgical management of spinal infections: a multidisciplinary approach

OBJECT

Infections along the spinal axis are characterized by an insidious onset, and the resulting delays in diagnosis are associated with serious neurological consequences and even death. Infections of the spine can affect the vertebral bodies, intervertebral discs, spinal canal, and surrounding soft tissues. Neurological dysfunction occurs when the spinal cord becomes compressed, edematous, or ischemic due to compression by abscess or vascular compromise. The aim of this paper was to detail general diagnostic and management principles for this disease.

METHODS

Recent progress in medical technologies, including the development of potent antimicrobial drugs, advanced imaging, and improved surgical methods, have dramatically reduced morbidity and mortality rates for spinal infections; however, debate still exists on the proper management of this disease. In this paper, the authors review the current management protocols for spinal infections at their institution, focusing on medical and surgical treatments for vertebral osteomyelitis, intervertebral disc space infections, and spinal canal and soft-tissue abscesses.

CONCLUSIONS

Technological advances in imaging modalities, pharmaceutics, and surgery have resulted in excellent outcomes and have greatly reduced the morbidity and mortality rates associated with spinal infections. Currently, treatment of spinal infections requires a multidisciplinary team that includes infectious diseases experts, neuroradiologists, and spine surgeons. The key to successful management of spinal infections is early detection.

The role of magnetic resonance imaging in the diagnosis of postoperative spondylodiscitis

BACKGROUND

Spondylodiscitis, discitis associated with vertebral osteomyelitis may follow disc-removal surgery. A targeted successful treatment of spinal infections requires clinical and laboratory data that are completed by the contribution of imaging procedures. Neuroimaging provides precise information on correct topography, localization, propagation, and differential diagnosis of spinal infectious lesions. The aim of this study was to present magnetic resonance imaging (MRI) findings in patients with postoperative spondylodiscitis.

METHODS

MRI was performed in 6 patients aged 29-50, with clinically suspected postoperative spondylodiscitis. Initial examination was performed 3-8 weeks after surgery and 3, 6, or 12 months after the treatment by antibiotics. Patients underwent MRI on a IT imaging unit (Siemens, Magnetom-Impact), including sagittal T1W and T2W images and axial T1W images before and after the administration of gadolinium contrast medium.

RESULTS

MRI findings included: significantly decreased signal intensity with the loss of distinction between vertebral body and intervertebral disc space on T1W, increased signal intensity in the adjacent vertebral body and end-plates on T2W, contrast enhancement of vertebral body and disc space and paravertebral soft tissue changes. Follow-up examinations performed 3, 6, or 12 months after the treatment showed less abnormal signal intensities on both T1- and T2-weighted images.

CONCLUSION

Postoperative spondylodiscitis is a rare but severe complication of lumbar disc surgery. Since conventional imaging techniques are not reliable for detecting spondylodiscitis in its early stages, MRI is of great significance in the diagnosis of postoperative spondylodiscitis.

Management of postprocedural discitis

BACKGROUND CONTEXT

Fortunately, the incidence of postprocedural discitis is relatively uncommon. The paucity of physical examination findings behooves the spine care practitioner to have a high index of suspicion in any patient presenting with increasing back pain after an invasive spinal procedure. The diagnosis can often be established in a timely fashion based on the history, physical examination, laboratory studies (erythrocyte sedimentation rate, C-reactive protein and blood cultures) and imaging studies (plain radiographs, magnetic resonance imaging, computed tomography and radionuclide scanning).

PURPOSE

To review the English literature on the subject of postprocedural discitis. The incidence, pathophysiology, laboratory markers and imaging findings are discussed. Recommendations on treatment strategies are presented along with long-term clinical outcomes of this postprocedure complication.

METHODS

A contemporary English literature search of MEDLINE and PubMed on the topic of postoperative discitis was performed.

RESULTS

The incidence of postprocedural discitis is approximately 0.2%. The most common etiologic agent is Staphylococcus aureus. The C-reactive protein is the most sensitive clinical laboratory marker to assess the presence of infection and effectiveness of treatment response. Magnetic resonance imaging is the imaging modality of choice in the diagnosis of spinal infection. The majority of patients are managed adequately with organism-specific antibiotics and spinal immobilization with good long-term outcomes. Operative intervention (open biopsy followed by antibiotic treatment and spinal immobilization or debridement and reconstruction) in patients who fail to respond to nonoperative treatment or in the presence of neurologic worsening has been demonstrated.

CONCLUSION

Postprocedural discitis is a rare complication after any invasive spinal procedure. It is imperative for the treating surgeon to maintain a high index of suspicion. Appropriate laboratory and imaging studies are invaluable in establishing a timely diagnosis. In the majority of patients, antibiotic treatment along with spinal immobilization has been shown to produce good long-term outcomes. Operative intervention is rarely necessary in patients failing conservative treatment.