C-reactive protein in spinal surgery: more predictive than prehistoric

Prediction models for risk assessment of surgical site infection after spinal surgery: A systematic review

Background

Spinal surgeries are a common procedure, but there is significant risk of adverse events following these operations. While the rate of adverse events ranges from 8% to 18%, surgical site infections (SSIs) alone occur in between 1% and 4% of spinal surgeries.

Methods

We completed a systematic review addressing factors that contribute to surgical site infection after spinal surgery. From the included studies, we separated the articles into groups based on whether they propose a clinical predictive tool or model. We then compared the prediction variables, model development, model validation, and model performance.

Results

About 47 articles were included in this study: 10 proposed a model and 5 validated a model. The models were developed from 7,720 participants in total and 210 participants with SSI. Only one of the proposed models was externally validated by an independent group. The other 4 validation papers examined the performance of the ACS NSQIP surgical risk calculator.

Conclusions

While some preoperative risk models have been validated, and even successfully implemented clinically, the significance of postoperative SSIs and the unique susceptibility of spine surgery patients merits the development of a spine-specific preoperative risk model. Additionally, comprehensive and stratified risk modeling for SSI would be of invaluable clinical utility and greatly improve the field of spine surgery.

Logistic regression model predicts early surgical site infection after spinal fusion: a retrospective cohort study

OBJECTIVE

This study aimed to develop a diagnostic model for predicting early surgical site infection (SSI) based on postoperative inflammatory markers after spinal fusion surgery.

METHODS

In this retrospective study, we analysed the trends of inflammatory markers between SSI and non-SSI groups. The data were randomly divided into training cohort and validation cohort (ratio 7:3). The variables for SSI were analysed using stepwise logistic regression to develop the prediction model. To evaluate the model, we analysed its sensitivity, specificity, positive predictive value, negative predictive value, as well as the area under the curve in the validation cohort. Calibration plots and decision curve analysis were employed to assess the calibration and clinical usefulness of the model.

FINDINGS

We observed significant changes in inflammatory markers on the seventh day after surgery. The prediction model included four variables on the seventh day after surgery: body temperature, C-reactive protein, erythrocyte sedimentation rate and neutrophil counts. After binary processing of these data, the simplified model achieved an area under the curve of 0.86 (95% confidence interval (CI): 0.81-0.92) in the training cohort and 0.9 (95% CI: 0.82-0.98) in the validation cohort. Calibration plots and decision curve analysis demonstrated that the proposed model was effective for the diagnosis of SSI.

CONCLUSION

We developed and validated a prediction model for diagnosing early infection after spinal fusion.

Is an Elevated Preoperative CRP Level a Predictive Factor for Wound Healing Disorders following Lumbar Spine Surgery?

Postoperative wound infections are a prevalent concern among the hospital-associated infections in Europe, leading to prolonged hospital stays, increased morbidity and mortality, and substantial patient burdens. Addressing the root causes of this complication is crucial, especially given the rising number of spine surgeries due to aging populations.

METHODS

A retrospective analysis was conducted on a cohort of 3019 patients who underwent lumbar spine surgery over a decade in our department. The study aimed to assess the predictors of wound healing disorders, focusing on laboratory values, particularly inflammatory parameters.

RESULTS

Of the 3019 patients, 2.5% (N = 74) experienced deep or superficial wound healing disorders, showing the significant correlation between C-reactive protein (CRP) levels and these disorders (p = 0.004). A multivariate analysis identified several factors, including age, sex, hypertension, diabetes, cardiac comorbidity, surgical duration, dural injury, and blood loss, as being correlated with wound healing disorders.

CONCLUSION

Demographic factors, pre-existing conditions, and perioperative variables play a role in the occurrence of adverse effects related to wound healing disorders. Elevated CRP levels serve as an indicator of increased infection risk, though they are not a definitive diagnostic tool for wound healing disorders.

Interleukin-6 as a critical inflammatory marker for early diagnosis of surgical site infection after spine surgery

PURPOSE

Early diagnosis of surgical site infections (SSIs) could prevent surgical revision. Inflammatory markers (IMs), such as procalcitonin (PCT), interleukin-6 (IL-6), and tumor necrosis factor α (TNF-α), seem more accurate in diagnosing SSI than C-reactive protein (CRP) and white blood cell (WBC) count. The aim was to compare the predictive values of CRP, WBC count, PCT, IL-6, and TNF-α in SSI detection.

METHODS

A total of 130 patients undergoing dorsal spondylodesis from 2019 to 2024 were enrolled in a prospective diagnostic study at a maximum care spine center. IMs were measured preoperatively and on the postoperative days (PODs) 1, 2, 3, 5, and 7. Patients with high suspicion of SSI underwent revision surgery. SSI was diagnosed when the microbiological evidence was positive. Patients were divided a posteriori into the non-infection and infection groups.

RESULTS

IMs of 118 patients (66.9 ± 13.0 years, 61.0% females) were measured. Fifteen of the 118 patients (12.7%) developed an SSI. The groups differed with respect to existing hypertension, number of instrumented segments, region of surgery, CRPPOD1,7, PCTPOD7, and IL-6POD3,5,7. Binary logistic regression for SSI detection including these parameters showed an area under the curve (AUC) of 0.88 (95% CI 0.79-0.98; P < 0.001). The main effect for SSI detection was maintained by IL-6POD7 (odds ratio = 1.13; 95% CI 1.05-1.23; P = 0.001), which itself showed an AUC of 0.86 (95% CI 0.75-0.97).

CONCLUSION

Compared to CRP, WBC count, PCT, and TNF-α, IL-6 seems to be the critical IM for the early detection of an SSI.

TRIAL REGISTRATION

drks.de: DRKS00033773, date of registration: 29.02.2024, retrospectively registered; Postoperative Markers of Inflammation in Spine Surgery (POMIS) Trial.

Does the use of epicutaneous vacuum-assisted closure after revision surgery on the spine reduce further wound revision surgery?

PURPOSE

This study aimed to investigate the effect of epicutaneous vacuum therapy on the rate of unplanned spinal wound revisions compared with conventional wound dressing.

METHODS

This retrospective study included patients who underwent unplanned revision spine surgery after primary aseptic spine surgery who were treated at a level I spine centre between December 2011 and December 2019. Patients with revision surgery who required a further unplanned revision surgery during the inpatient stay were considered a treatment failure. The epicutaneous vacuum-assisted closure (Epi-VAC) therapy was the standard treatment method beginning in 2017 (the epi-VAC group). Before, conventional wound dressing was used (the control group (CG)). In addition, a one-to-one matched-pair comparison analysis was performed between both groups.

RESULTS

Of 218 patients, 48 were in the epi-VAC group. The mean age was 65.1 years (epi-VAC 68.2 to CG 64.3 years (P = 0.085)), and the mean body mass index (BMI) was 28.2 kg/m2 (epi-VAC 29.4 to CG 27.9 kg/m2 (P = 0.16)). No significant differences in the treatment failure rate could be detected between the two groups (epi-VAC 25% to CG 22.4% (P = 0.7)). There was also no significant difference for the matched-pair analysis (epi-VAC 26.1% to CG 15.2% (P = 0.3)). An elevated CRP level (C-reactive protein) immediately before the first wound revision was a significant risk factor for further revision surgery (treatment failure: 135.2 ± 128.6; no treatment failure: 79.7 ± 86.1 mg/l (P < 0.05)).

CONCLUSION

Concerning repeat unplanned wound revision after spinal revision surgery, we cannot demonstrate an advantage of the epicutaneous vacuum therapy over conventional wound dressing.

No more tears from surgical site infections in interventional pain management

As the field of interventional pain management (IPM) grows, the risk of surgical site infections (SSIs) is increasing. SSI is defined as an infection of the incision or organ/space that occurs within one month after operation or three months after implantation. It is also common to find patients with suspected infection in an outpatient clinic. The most frequent IPM procedures are performed in the spine. Even though primary pyogenic spondylodiscitis via hematogenous spread is the most common type among spinal infections, secondary spinal infections from direct inoculation should be monitored after IPM procedures. Various preventive guidelines for SSI have been published. Cefazolin, followed by vancomycin, is the most commonly used surgical antibiotic prophylaxis in IPM. Diagnosis of SSI is confirmed by purulent discharge, isolation of causative organisms, pain/tenderness, swelling, redness, or heat, or diagnosis by a surgeon or attending physician. Inflammatory markers include traditional (C-reactive protein, erythrocyte sedimentation rate, and white blood cell count) and novel (procalcitonin, serum amyloid A, and presepsin) markers. Empirical antibiotic therapy is defined as the initial administration of antibiotics within at least 24 hours prior to the results of blood culture and antibiotic susceptibility testing. Definitive antibiotic therapy is initiated based on the above culture and testing. Combination antibiotic therapy for multidrug-resistant Gram-negative bacteria infections appears to be superior to monotherapy in mortality with the risk of increasing antibiotic resistance rates. The never-ending war between bacterial resistance and new antibiotics is continuing. This article reviews prevention, diagnosis, and treatment of infection in pain medicine.

Comparison of Perioperative Outcomes in Patients Undergoing Short-Level Lumbar Fusion Surgery After Implementing Enhanced Recovery After Surgery: A Propensity Score Matching Analysis Focusing on Young-Old and Old-Old

Background

There were exponentially increased studies focused on revealing the satisfactory outcomes after implementing enhanced recovery after surgery (ERAS) in patients undergoing lumbar fusion surgery. However, little attention has been paid to the impact of chronologic age alone on perioperative outcomes.

Methods

In the present study, patients were dichotomized into two groups: young-old (65-79 years), and old-old (80 years and older). Given the heterogeneity and age-related comorbidities in this population and the need to compare similar groups, we performed propensity score matching for gender, body mass index (BMI), operation time, American Society of Anesthesiologists (ASA) grade, Charlson Comorbidity Index (CCI), fusion levels and frail status. Perioperative outcomes were compared between two groups.

Results

In our study, we found there were significant discrepancies in length of stay (LOS) (7.17 ± 2.81 vs 8.11 ± 3.57 days, p = 0.031) and postoperative nausea and vomiting (3.7% vs 11.0%, p = 0.038); however, there were no significant differences in C-reactive protein (21.50 ± 26.52 vs 19.22 ± 22.04 mg/L, p = 0.490), overall complication rates (24.8% vs 33.0%, p = 0.179), ambulation time (2.89 ± 1.34 vs 2.55 ± 1.49 days, p = 0.078) or removal of urinary catheter time (2.47 ± 1.44 vs 2.32 ± 1.40 days, p = 0.446).

Conclusion

There were few differences in perioperative outcomes between young-old and old-old groups. Despite similar postoperative complication rates, the old-old group might experience longer LOS when complications occur. More importantly, current outcomes suggested that chronologic age alone does not appear to have the capacity to reflect the tolerance of elderly patients to surgery.

C-reactive protein to lymphocyte ratio as a new biomarker in predicting surgical site infection after posterior lumbar interbody fusion and instrumentation

Purpose

This study aims to evaluate the potential of C-reactive protein to lymphocyte count ratio (CLR) for the prediction of surgical site infection (SSI) following posterior lumbar interbody fusion (PLIF) and the instrumentation of lumbar degenerative diseases.

Methods

In this retrospective study, we considered patients with a lumbar degenerative disease diagnosis surgically treated by the instrumented PLIF procedure from 2015 to 2021. Patient data, including postoperative early SSI and other perioperative variables, were collected from their respective hospitalization electronic medical records. The receiver operator characteristic curve was constructed to determine the optimal cut-off value for CLR, and the ability to predict SSI was evaluated by the area under the curve (AUC). According to the cut-off value, patients were dichotomized with high- or low-CLR, and between-group differences were compared using univariate analysis. The independent impact of CLR on predicting SSI was investigated by multivariate logistics regression analysis.

Results

A total of 773 patients were included, with 26 (3.4%) developing an early SSI post-operation. The preoperative CLR was 11.1 ± 26.1 (interquartile range, 0.4–7.5), and the optimal cut-off was 2.1, corresponding to a sensitivity of 0.856, a specificity of 0.643, and an AUC of 0.768 (95% CI, 0.737–0.797). CLR demonstrated a significantly improved prediction ability than did lymphocyte count (P = 0.021) and a similar ability to predict an infection as C-response protein (P = 0.444). Patients with a high CLR had a significantly higher SSI incidence than those with a low CLR (7.6% vs. 0.8%, P < 0.001). After adjustment for numerous confounding factors, CLR ≥ 2.1 was associated with an 11.16-fold increased risk of SSI, along with other significant variables, i.e., diabetes, preoperative waiting time, and surgical duration.

Conclusion

A high CLR exhibited an improved ability to predict incident SSI and was associated with a substantially increased risk of SSI following instrumented PLIF. After better-design studies verified this finding, CLR could potentially be a beneficial tool in surgical management.

The Impact of Frailty on Perioperative Outcomes in Patients Receiving Short-Level Posterior Lumbar Interbody Fusion: A Stepwise Propensity Score Matching Analysis

Background

There are many studies on the impact of frailty on postoperative complications; however, there are few studies focusing on stepwise propensity score matching (PSM) to offset the influence of age.

Methods

We gathered data for patients undergoing short-level posterior lumbar interbody fusion from January to December 2021. According to the Fried frailty phenotype, we categorized patients into non-frail, pre-frail, and frail groups, then, stepwise PSM for age, sex, American Society of Anesthesiologists (ASA) and fusion levels were performed to keep comparable clinical data between groups. Univariate and multivariate logistic regressions were used to determine the impact of clinical demographics on postoperative complications.

Results

A total of 559 consecutive patients with complete medical records were enrolled (237 males and 322 females; mean age 72.55 ± 5.86 years). After PSM, we found that pre-frail patients were more vulnerable to develop urinary retention (p = 0.031) and surgical site infections (p = 0.021) than non-frail patients. Longer length of stay (LOS), delayed ambulation and removal of urinary catheter times were observed in pre-frail patients. However, there was a significant difference only in LOS between pre-frail and frail patients. Binary logistic regression revealed that C-reactive protein (CRP) and frail status were independently associated with postoperative complications between non-frail and pre-frail patients, while only CRP was independently correlated with complications between pre-frail and frail patients.

Conclusion

After PSM, we found higher rates of urinary retention and surgical site infections in pre-frail patients than in non-frail patients. CRP was independently related to postoperative complications, while frail status was only independently associated with postoperative complications between pre-frail and non-frail patients. Pre-frail/frail patients tended to have more severe stress responses than non-frail patients.

A nomogram for predicting post-operative wound complications after open reduction and internal fixation for calcaneal fractures

The purpose of our study was to determine the risk factors for post-operative wound complications (PWCs) after open reduction and internal fixation (ORIF) for calcaneal fracture and establish a nomogram prediction model. We retrospectively analysed the clinical data of patients who suffered from calcaneal fractures and had been surgically treated for ORIF in our institution between January 2010 and January 2020. Perioperative information was obtained through the electronic medical record system, univariate and multivariate analyses were performed to determine the risk factors of PWCs, and a nomogram model was constructed to predict the risk of PWCs. The predictive performance and consistency of the model were evaluated by the Hosmer -Lemeshow (H-L) test and the calibration curve. In total, 444 patients were enrolled in our study. Multivariate analysis results showed that smoking, limb swelling, angle of incision, and CRP were independent risk factors for skin necrosis. The AUC value for skin necrosis risk was 0.982 (95%CI 0.97-0.99). The H-L test revealed that the normogram prediction model had good calibration ability (P = .957). Finally, we found a correlation between PWCs and smoking, limb swelling, angle of incision, and CRP after ORIF for calcaneal fracture patients. Our nomogram prediction model might be helpful for clinicians to identify high-risk patients, as interventions could be taken early to reduce the incidence of PWCs.

Predicting the Exception-CRP and Primary Hip Arthroplasty

BACKGROUND

While primary hip arthroplasty is the most common operative procedure in orthopedic surgery, a periprosthetic joint infection is its most severe complication. Early detection and prediction are crucial. In this study, we aimed to determine the value of postoperative C-reactive protein (CRP) and develop a formula to predict this rare, but devastating complication.

METHODS

We retrospectively evaluated 708 patients with primary hip arthroplasty. CRP, white blood cell count (WBC), and several patient characteristics were assessed for 20 days following the operative procedure.

RESULTS

Eight patients suffered an early acute periprosthetic infection. The maximum CRP predicted an infection with a sensitivity and specificity of 75% and 56.9%, respectively, while a binary logistic regression reached values of 75% and 80%. A multinominal logistic regression, however, was able to predict an early infection with a sensitivity and specificity of 87.5% and 78.9%. With a one-phase decay, 71.6% of the postoperative CRP-variance could be predicted.

CONCLUSION

To predict early acute periprosthetic joint infection after primary hip arthroplasty, a multinominal logistic regression is the most promising approach. Including five parameters, an early infection can be predicted on day 5 after the operative procedure with 87.5% sensitivity, while it can be excluded with 78.9% specificity.

A Novel Technique for Treating Early Deep Surgical Site Infection After Posterior Lumbar Fusion with Instrumentation

OBJECTIVE

To introduce a novel technique of using incisional vacuum-assisted closure (VAC) after 1-stage incision suture combined with closed suction irrigation system (CSIS) for treating early deep surgical site infection (SSI) after posterior lumbar fusion with instrumentation and to compare it with traditional CSIS.

METHODS

This was a retrospective study. Patients with early deep SSI after posterior lumbar fusion with instrumentation from January 2013 to May 2020 who were treated by meticulous debridement followed by either CSIS or incisional VAC after 1-stage incision suture combined with CSIS were identified. The demographic characteristics, treatment features, and outcomes were analyzed and compared between the 2 treatment methods.

RESULTS

A total of 48 patients (48/5016, 0.96%) developed early deep SSI, 46 of whom were enrolled in this study. This included 24 patients in the CSIS group (group 1) and 22 patients in the incisional VAC after 1-stage incision suture combined with CSIS group (group 2). All patients received follow-up, with an average of 19.7 months (range, 13-30 months). There were no significant differences in demographic characteristics in both groups (P > 0.05). The number of VAC foam dressing or ordinary dressing changes (P < 0.001), number of debridements (P = 0.028), intravenous antibiotic duration (P = 0.042), oral antibiotic duration (P = 0.019), and hospital stay (P = 0.029) in group 1 were significantly higher than those in group 2. The irrigation duration in group 1 was significantly shorter than that in group 2 (P = 0.007). All patients were eventually cured with satisfactory outcomes.

CONCLUSIONS

Compared with CSIS, incisional VAC after 1-stage incision suture combined with CSIS may be recommended considering that it has fewer dressing changes, fewer debridements, longer irrigation duration, shorter duration of antibiotic use, shorter hospital stay, and more convenient nursing care.

Predictive Value of C-Reactive Protein for Early Postoperative Complications in Children After Hypospadias Surgery

Background: This study explored the predictive value of postoperative C-reactive protein in children with hypospadias for postoperative complications and the risk factors. Methods: The clinical and follow-up data of 106 children with hypospadias who were treated with operations at Kunming Children's Hospital in 2020 were, respectively, analyzed. According to the occurrence of postoperative complications, the patients were divided into two groups: 25 patients with postoperative complications were the complications group, and 81 without postoperative complications were the control group. The baseline data, clinical characteristics, laboratory test indexes, and outcome of the two groups were collected. Receiver operating characteristic (ROC) was used to calculate the optimal cutoff value of C-reaction protein (CRP). Logistic regression was used to analyze the risk factors of hypospadias after surgery. A probability value (P) < 0.05 was considered statistically significant. Results: According to the result of the ROC curve, the optimal cutoff value of CRP was 11.7 mg/L. Logistic regression showed that the length of urethral defect, the urethral material, the operative produce, and the postoperative CRP level were related to the occurrence of postoperative complications of patients with DCC. The length of the urethral defect and the CRP level were the independent risk factors of the prognosis of hypospadias patients. The CRP level was related to the occurrence of postoperative complications and fistula. Conclusions: Postoperative CRP level can be used as a reliable marker for predicting the prognosis of hypospadias patients.