Clinical outcomes after lumbar fusion complicated by deep wound infection: a case-control study

Prophylactic closed-incisional negative pressure wound therapy following posterior instrumented spinal fusion: a single surgeon's experience and cost-benefit analysis

PURPOSE

Surgical site infections (SSIs) following spine surgery are associated with morbidity and resource utilization. Applying prophylactic closed-incisional negative pressure wound therapy (ciNPWT) during posterior instrumented fusion has mixed results in reducing rates of wound complications and SSI. We evaluated the clinical efficacy and potential cost-savings associated with ciNPWT in high-risk patients receiving posterior instrumented spinal fusion.

METHODS

We retrospectively reviewed patients receiving posterior instrumented spinal fusion for any surgical indication between July 1, 2017 and December 31, 2019, and compared rates of wound dehiscence, SSI, and reoperation for wound complications between standard surgical dressings and ciNPWT. Surgical dressing selection was based on the senior author's assessment of infection risk factors.

RESULTS

A total of 229 patients (n = 85 standard surgical dressings, n = 144 ciNPWT) were included. The ciNPWT group had significantly more risk factors for wound-related complications, including older age (61.8 vs. 58.5 years, p = 0.042), diabetes mellitus (36.8% vs. 23.5%, p = 0.037), more instrumented levels (5.6 vs. 3.9, p < 0.0001), estimated blood loss (1298 vs. 998 mL, p = 0.036), and deformity was the predominant operative indication (29.9% vs. 17.7%, p = 0.040). Prophylactic ciNPWT was associated with significantly lower rates of wound dehiscence (21.5% vs. 34.1%, p = 0.036) and SSI (8.3% vs. 21.2%, p = 0.005). Number needed to treat with ciNPWT to prevent one SSI was 8 patients. The cost of preventing one SSI was $4,560. Cost-benefit analysis demonstrated a potential mean savings of $21,662 per operative SSI prevented and $270,775 per 100 patients undergoing posterior instrumented fusion with ciNPWT.

CONCLUSIONS

Prophylactic ciNPWT use is a cost-effective means of reducing rates of wound dehiscence and SSI following posterior instrumented fusion.

Does surgical site infection affect patient-reported outcomes after spinal surgery? A multicenter cohort study

BACKGROUND

Surgical site infections are common in spinal surgeries. It is uncertain whether outcomes in spine surgery patients with vs. without surgical site infection are equivalent. Therefore, we assessed the effects of surgical site infection on postoperative patient-reported outcomes.

METHODS

We enrolled patients who underwent elective spine surgery at 12 hospitals between April 2017 and February 2020. We collected data regarding the patients' backgrounds, operative factors, and incidence of surgical site infection. Data for patient-reported outcomes, namely numerical rating scale, Neck Disability Index/Oswestry Disability Index, EuroQol Five-Dimensional questionnaire, and 12-Item Short-Form Health Survey scores, were obtained preoperatively and 1 year postoperatively. We divided the patients into with and without surgical site infection groups. Multivariate logistic regression analyses were performed to identify the risk factors for surgical site infection. Using propensity score matching, we obtained matched surgical site infection-negative and -positive groups. Student's t-test was used for comparisons of continuous variables, and Pearson's chi-square test was used to compare categorical variables between the two matched groups and two unmatched groups.

RESULTS

We enrolled 8861 patients in this study; 74 (0.8 %) developed surgical site infections. Cervical spine surgery and American Society of Anesthesiologists physical status classification ≥3 were identified as risk factors; microendoscopy was identified as a protective factor. Using propensity score matching, we compared surgical site infection-positive and -negative groups (74 in each group). No significant difference was found in postoperative pain or dysesthesia of the lower back, buttock, leg, and plantar area between the groups. When comparing preoperative with postoperative pain and dysesthesia, statistically significant improvement was observed for both variables in both groups (p < 0.01 for all variables). No significant differences were observed in postoperative outcomes between the matched surgical site infection-positive and -negative groups.

CONCLUSIONS

Patients with surgical site infections had comparable postoperative outcomes to those without surgical site infections.

Association of modic changes and postoperative surgical site infection after posterior lumbar spinal fusion

PURPOSE

Postoperative surgical site infection is one of the most serious complications following spine surgery. Previous studies have reported Modic changes (MC) represent a subclinical infection. This study aims to investigate the relation between Modic changes and surgical site infection after posterior lumbar fusion surgery.

METHODS

We retrospectively reviewed the records of 424 patients who received posterior lumbar fusion. Preoperative clinical and radiological parameters were recorded. Primary outcome was the rate of postoperative surgical site infection. Covariates included age, body mass index (BMI), sex, hypertension, diabetes mellitus, chronic heart failure, Pfirrmann classification, fused levels, and operation duration. The presence of Modic changes was used as an exposition variable, and adjusted for other risk factors in multivariate analyses.

RESULTS

Of the 424 patients, 30 (7%) developed an acute surgical site infection. Infection had no relation to age, sex, BMI, and comorbidities. There were 212 (50%) patients with MC, and 23 (10.8%) had a surgical site infection, compared to 212 (50%) patients without MC in which there were 7 (3.3%) surgical site infections. MC was associated with surgical site infection in univariate analysis (odds ratio [OR] = 3.56, 95% confidence interval [CI]: 1.49-8.50, p = 0.004) and multivariate logistic regression analysis (OR = 3.05, 95% CI: 1.26-7.37, p = 0.013). There was statistically significant between specific type (p = 0.035) and grade of MCs (p = 0.0187) and SSI.

CONCLUSIONS

MCs may be a potential risk factor for SSI following posterior lumbar spinal intervertebral fusion. Type I and grade C MCs showed a higher infection rate compared with other MC types and grades.

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.

Removal of Spinal Instrumentation Is Not Required to Successfully Treat Postoperative Wound Infections in Most Cases

INTRODUCTION

Controversy exists regarding whether spinal implants need to be removed to treat postoperative deep wound infections (DWIs). This retrospective study aimed to determine whether the removal or retention of implants impacts the successful treatment of a DWI after spine surgery.

METHODS

Postoperative spine surgery patients presenting with signs of infection who underwent irrigation and debridement (I&D) at Twin Cities Spine Surgeons at Abbott Northwestern Hospital, Minnesota, USA, were studied. First, the persistence of infection when implants were retained or removed was assessed. Second, we analyzed the persistence of infection with respect to the number of I&D, the use of vacuum-assisted closure (VAC) treatment, pseudoarthrosis status, and functional outcomes.

RESULTS

One hundred thirty-five patients were included. Treatment of infection with retention of implants occurred in 64% (87/135); of these, 7% (6/87) had a persistent infection. Of patients with implant removal (36%, 48/135), 6% (3/48) had a persistent infection. Thus, we observed no difference between treatment with implants present compared to implants removed (p = 1.0). Fifty of the 135 patients (37%) received I&D and primary wound closure, and 85 (63%) patients received I&D and VAC treatment. There was no statistical difference between primary wound closure and VAC treatment (p = 0.15) with respect to persistence. Repeat I&D with VAC (three or more times) had a significantly lower rate of recurrence than those with two I&Ds. Pseudoarthrosis and persistent infection were unrelated. At minimum one-year follow-up, achieving a minimum clinically important difference in functional outcome was independent of persistent infection status.

CONCLUSION

Persistent infection was unrelated to the retention of implants. When VAC treatment was deemed necessary, more than two I&Ds resulted in a significantly better cure for infection. Those with a persistent infection were no more likely to exhibit pseudoarthrosis than those with no persistent infection. All patients showed improvement in functional outcomes at minimum one-year follow-up.

Preoperative Epidural Steroid Injections and Postoperative Infections After Lumbar or Cervical Spine Surgery: A Systematic Review and Meta-Analysis

Objective

To determine the risk difference and 95% prediction intervals (PIs) for postoperative infections (POIs) associated with preoperative epidural steroid injections (ESIs) in adults undergoing lumbar or cervical spine surgery.

Methods

Comprehensive database searches were conducted from inception dates through December 2023. Inclusion criteria included all study designs involving adults receiving a preoperative ESI before lumbar or cervical decompression or fusion spine surgery. Risk of bias was assessed using a modified tool developed for uncontrolled studies. The summary estimates of risk difference and the corresponding PIs were reported.

Results

A total of 12 studies were included in the systematic review, of which 9 were included in the meta-analysis. Preoperative ESIs within 1 month of lumbar spine decompression or fusion surgery were associated with a 0.6% and 2.31% greater risk of a POI, respectively. In adults ≥65 years of age, ESIs within 1 or 1-3 months of lumbar spine decompression or fusion surgery were associated with a 1.3% and 0.6% greater risk of a POI, respectively. Preoperative ESIs within 3 months of cervical spine fusion were not associated with an increased risk of a POI. The bounds of all corresponding 95% PIs were nonsignificant.

Conclusion

The observations of this study provide summary estimates of risk difference and 95% PIs, which could be used to support shared decision-making about the use of ESIs before cervical or lumbar spine surgery.

Prevention of Surgical Site Infections in Spine Surgery: An International Survey of Clinical Practices Among Expert Spine Surgeons

STUDY DESIGN

Questionnaire-based survey.

OBJECTIVES

Surgical site infection (SSI) is a common complication in spine surgery but universal guidelines for SSI prevention are lacking. The objectives of this study are to depict a global status quo on implemented prevention strategies in spine surgery, common themes of practice and determine key areas for future research.

METHODS

An 80-item survey was distributed among spine surgeons worldwide via email. The questionnaire was designed and approved by an International Consensus Group on spine SSI. Consensus was defined as more than 60% of participants agreeing to a specific prevention strategy.

RESULTS

Four hundred seventy-two surgeons participated in the survey. Screening for Staphylococcus aureus (SA) is not common, whereas preoperative decolonization is performed in almost half of all hospitals. Body mass index (BMI) was not important for surgery planning. In contrast, elevated HbA1c level and hypoalbuminemia were often considered as reasons to postpone surgery. Cefazoline is the common drug for antimicrobial prophylaxis. Alcohol-based chlorhexidine is mainly used for skin disinfection. Double-gloving, wound irrigation, and tissue-conserving surgical techniques are routine in the operating room (OR). Local antibiotic administration is not common. Wound closure techniques and postoperative wound dressing routines vary greatly between the participating institutions.

CONCLUSIONS

With this study we provide an international overview on the heterogeneity of SSI prevention strategies in spine surgery. We demonstrated a large heterogeneity for pre-, peri- and postoperative measures to prevent SSI. Our data illustrated the need for developing universal guidelines and for testing areas of controversy in prospective clinical trials.

Local contamination is a major cause of early deep wound infections following open posterior lumbosacral fusions

PURPOSE

Postoperative surgical site infection in patients treated with lumbosacral fusion has usually been thought to be caused by perioperative contamination. With the proximity of these incisions to the perineum, this study sought to determine if contamination by gastrointestinal and/or urogenital flora should be considered as a major cause of this complication.

METHODS

We conducted a retrospective review of adults treated with open posterior lumbosacral fusions between 2014 and 2021 to identify common factors in deep postoperative infection and the nature of the infecting organisms. Cases of tumor, primary infection and minimally invasive surgery were excluded.

RESULTS

489 eligible patients were identified, 20 of which required debridement deep to the fascia (4.1%). Mean age, operative time, estimated blood loss and levels fused were similar between both groups. The infected group had a significantly higher BMI. The mean time from primary procedure to debridement was 40.8 days. Four patients showed no growth, 3 showed Staphylococcus sp. infection (Perioperative Inside-Out) requiring debridement at 63.5 days. Thirteen showed infection with intestinal or urogenital pathogens (Postoperative Outside-In) requiring debridement at 20.0 days. Postoperative Outside-In infections led to debridement 80.3 days earlier than Perioperative Inside-Out infections (p = 0.007).

CONCLUSIONS

65% of deep infections in patients undergoing open lumbosacral fusion were due to early contamination by pathogens associated with the gastrointestinal and/or urogenital tracts. These required earlier debridement than Staphylococcus sp.

INFECTIONS

There should be renewed focus on keeping these pathogens away from the incision during the early stages of wound healing.

Effectiveness of Gentamicin Wound Irrigation in Preventing Surgical Site Infection During Lumbar Spine Surgery: A Retrospective Study at a Rural Teaching Hospital in India

BACKGROUND

Surgical site infections (SSIs) are an opposing result of surgery and account for the majority of healthcare-related infections worldwide. It is one of the most common complications associated with open-spine surgery and is associated with high rates of mortality and high demand for healthcare resources. Surgical site infections are the result of a variety of reasons, which is why a range of prevention strategies have been proposed. Intraoperative wound irrigation (IOWI) is a simple procedure that involves moving a solution through an open wound to help hydrate the tissue. It is a type of prophylactic wound irrigation. It removes and dilutes bodily fluids, bacteria, and cellular debris. It may also act as a bactericidal agent when used with antibiotics and antiseptics.

AIMS AND OBJECTIVES

To evaluate the incidence of SSI in lumbar spine surgeries by comparing IOWI with normal saline containing gentamicin (NS-G) and normal saline (NS) alone.

MATERIALS AND METHOD

A hospital-based retrospective study was conducted among 40 patients who underwent elective lumbar spine surgery at the Department of Orthopaedics, RL Jalappa Hospital Centre, Kolar, Karnataka, India.

RESULT

Out of the total participants enrolled, 60% were males and 40% were females. There was no statistically significant difference found between mean age, mean BMI, mean hemoglobin level, mean WBC counts, and mean fasting blood sugar (FBS) levels among both groups. The overall prevalence of SSI among patients was 25%. In Group A (NS-G), the prevalence of SSI was 15%, and in Group B (NS), it was 35%. In total, 17.5% of study participants had superficial SSI, while 7.5% had deep SSI.

CONCLUSION

Gentamicin, an aminoglycoside antibiotic, is bactericidal and efficient against gram-positive organisms like Staphylococcus, the most frequent pathogen causing SSI in spine surgery. During lumbar spine surgery, IOWI with saline and gentamicin before closure is more effective in preventing SSI than simple saline irrigation.

Impact of surgical-site infection on health utility values: a meta-analysis

BACKGROUND

Surgical-site infections (SSIs) are recognized as negatively affecting patient quality of life. No meta-analysis of SSI utility values is available in the literature to inform estimates of this burden and investment decisions in prevention.

METHODS

A systematic search of PubMed, MEDLINE, CINAHL, and the National Health Service Economic Evaluation Database was performed in April 2022 in accordance with PROSPERO registration CRD 42021262633. Studies were included where quality-of-life data were gathered from adults undergoing surgery, and such data were presented for those with and without an SSI at similar time points. Two researchers undertook data extraction and quality appraisal independently, with a third as arbiter. Utility values were converted to EuroQol 5D (EQ-5D™) estimates. Meta-analyses were conducted using a random-effects model across all relevant studies, with subgroup analyses on type and timing of the SSI.

RESULTS

In total, 15 studies with 2817 patients met the inclusion criteria. Six studies across seven time points were used in the meta-analysis. The pooled mean difference in EQ-5D™ utility in all studies combined was -0.08 (95 per cent c.i. -0.11 to -0.05; prediction interval -0.16 to -0.01; I2 = 40 per cent). The mean difference in EQ-5D™ utility associated with deep SSI was -0.10 (95 per cent c.i. -0.14 to -0.06; I2 = 0 per cent) and the mean difference in EQ-5D™ utility persisted over time.

CONCLUSION

The present study provides the first synthesized estimate of SSI burden over the short and long term. EQ-5D™ utility estimates for a range of SSIs are essential for infection prevention planning and future economic modelling.

Prevention of Surgical Site Infection Following Open Spine Surgery: The Efficacy of Intraoperative Wound Irrigation with Normal Saline Containing Gentamicin Versus Dilute Povidone-Iodine

BACKGROUND

Intraoperative wound irrigation (IOWI) is an important step in preventing surgical site infection (SSI). This study compared the effectiveness of saline with gentamicin versus povidine-iodine (PI) as IOWI solutions in preventing SSI in open spine surgery.

METHODS

It is a prospective comparative study. Patients who had noninstrumented open spine surgery were randomized into 2 groups. Group A and B patients had their surgical wounds irrigated with saline containing gentamicin solution and dilute PI solution, respectively. Both groups were assessed for the occurrence of SSI.

RESULTS

A total of 80 patients, divided into 2 groups of 40 each completed the study. Overall, the SSI rate was 17.5% for patients in the normal saline containing gentamicin group (A) and 2.5% for those in the dilute PI group (B), this difference was statistically significant (P = 0.025). The cervical and thoracic spine regions have the same SSI rate (7.1% and 0%, respectively) in both groups. However, in the lumbosacral region, the SSI rate was 31.6% in A and 0% in B, this was statistically significant (P = 0.006). The isolated organisms in patients with SSI were staphylococcus species (42.86% of SSI in A and 0% in B) and pseudomonas species (42.86% of SSI in group A and 100% in group B), and this difference was profound in the lumbosacral spine region (P = 0.008).

CONCLUSIONS

IOWI with 3.5% dilute PI solution is more efficacious in preventing SSI and has wider microbial coverage compared to normal saline containing gentamicin solution as IOWI fluid in noninstrumented open spine surgery.

Surgical site infection in thoracic and lumbar fractures: incidence and risk factors in 11,401 patients from a nationwide administrative database

BACKGROUND CONTEXT

The rate of surgical site infection (SSI) following elective spine surgery ranges from 0.5%‒10%. Published reports suggest a higher SSI rate in non-elective spine surgery such as spine trauma; however, there is a paucity of large database studies examining this issue.

PURPOSE

The objective of this study was to investigate the incidence and risk factors of SSI in patients undergoing spine surgery for thoracic and lumbar fractures in a large population database.

STUDY DESIGN/SETTING

This is a retrospective study utilizing the PearlDiver Patient Claims Database.

PATIENT SAMPLE

Patients undergoing spine surgery for thoracic and lumbar fractures between 2015-2020 were identified in the PearlDiver Patient Claims Database using ICD-10 codes. Patients were excluded who had another surgery either 14 days before or 21 days after the index spine surgery, or pathologic fracture.

OUTCOME MEASURES

Rate of surgical site infection.

METHODS

Clinical data collected from the PearlDiver database based on ICD-10 codes included gender, age, diabetes, smoking status, obesity, Elixhauser Comorbidity Index (ECI), Charlson Comorbidity Index (CCI), and SSI. Univariate analysis was used to assess the association of potential risk factors and SSI. Multivariable analysis was used to identify independent risk factors of SSI. The authors have no conflicts of interest or funding sources to declare.

RESULTS

A total of 11,401 patients undergoing spine surgery for thoracic and lumbar fractures met inclusion criteria, and 1,065 patients were excluded. 860 patients developed SSI (7.5%). Risk factors significantly associated with SSI in univariate analysis included diabetes (OR 1.50; 95% CI, 1.30‒1.73; p<.001), obesity (OR 1.66; 95% CI, 1.44‒1.92; p<.001), increased age (p<.001), ECI (p<.001), and CCI (p<.001). On multivariable analysis, obesity and ECI were independently associated with SSI (p<.001 and p<.001, respectively).

CONCLUSIONS

Non-elective surgery for thoracic and lumbar fractures is associated with a 7.5% risk of SSI. Obesity and ECI are independent predictors of SSI in this population. Limitations include the reliance on accurate insurance coding which may not fully capture all SSI, and in particular superficial SSI. These findings provide a broad overview of the risk of SSI in this population at a national level and may also help counsel patients regarding risk.

Management of Deep Spinal Wound Infections Following Instrumentation Surgery with Subfascial Negative Pressure Wound Therapy

BACKGROUND AND STUDY AIMS

 The treatment of infections following a spine surgery continues to be a challenge. Negative pressure wound therapy (NPWT) has been an effective method in the context of infection therapy, and its use has gained popularity in recent decades. This study aims to analyze the impact of known risk factors for postoperative wound infection on the efficiency and length of NPWT therapy until healing.

PATIENTS AND METHODS

 We analyzed 50 cases of NPWT treatment for deep wound infection after posterior and posteroanterior spinal fusion from March 2010 to July 2014 retrospectively. We included 32 women and 18 men with a mean age of 69 years (range, 36-87 years). Individual risk factors for postoperative infection, such as age, gender, obesity, diabetes, immunosuppression, duration of surgery, intraoperative blood loss, and previous surgeries, as well as type and onset (early vs. late) of the infection were analyzed. We assessed the associations between these risk factors and the number of revisions until wound healing.

RESULTS

 In 42 patients (84%), bacterial pathogens were successfully detected by means of intraoperative swabs and tissue samples during first revision. A total of 19 different pathogens could be identified with a preponderance of Staphylococcus epidermidis (21.4%) and S. aureus (19.0%). Methicillin-resistant S. aureus (MRSA) was recorded in two patients (2.6%). An average of four NPWT revisions was required until the infection was cured. Patients with infections caused by mixed pathogens required a significantly higher number of revisions (5.3 vs. 3.3; p < 0.01) until definitive wound healing. For the risk factors, no significant differences in the number of revisions could be demonstrated when compared with the patients without the respective risk factor.

CONCLUSION

 NPWT was an effective therapy for the treatment of wound infections after spinal fusion. All patients in the study had their infections successfully cured, and all spinal implants could be retained. The number of revisions was similar to those reported in the published literature. The present study provides insights regarding the effectiveness of NPWT for the treatment of deep wound infection after spinal fusion. Further investigations on the impact of potential risk factors for postoperative wound healing disorders are required. Better knowledge on the impact of specific risk factors will contribute to a higher effectiveness of prophylaxis for postoperative wound infections considering the patient-specific situation.

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 effectiveness of percutaneous endoscopic lumbar discectomy combined with external lumbar drainage in the treatment of intervertebral infections

Objective

To analyze the effect of percutaneous endoscopic lumbar discectomy in treating lumbar intervertebral infections.

Methods

A total of 13 patients with lumbar intervertebral infections who underwent percutaneous endoscopic lumbar discectomy combined with external drainage between November 2016 and December 2019 were enrolled in the present study. After the operation, sensitive antibiotics were used based on the results of the bacterial culture. If no pathogens were detected in the biopsy culture of the infected tissues, empirical antibiotics were administrated to these patients. The clinical efficacy was evaluated by using a visual analog scale (VAS), Japanese Orthopaedic Association (JOA), Oswestry Disability Index (ODI), and standard Macnab's evaluation. Postoperative computed tomography (CT) and MRI were also used to evaluate clinical efficacy.

Results

The follow-up time was 10–18 months, and the average time was (13.69 ± 2.63) months. Causative bacteria were isolated in 7 of 13 infected tissue biopsy cultures. Systemic antibiotics and anti-tuberculous chemotherapy were administered according to sensitivity studies for identified. There were no pathogens isolated from the other six patients. Empiric antibiotics were administrated in these patients. One week after the operation, WBC, a fractional fraction of medium granulocytes, ESR and CRP were significantly lower compared to before the operation (all P < 0.05). At the last follow-up visit, the above-mentioned markers were all within normal range, which differed compared to the pre-operative data (P < 0.05). The VAS and ODI of the patients at 1 week and 3 months after operation were significantly lower compared to preoperative data (all P < 0.05). During the last follow-up visit, seven patients were excellent, five were good, and one was poor according to standard Macnab's evaluation. No serious complications were recorded.

Conclusions

Percutaneous lumbar discectomy combined with external drainage resulted as an effective method for treating lumbar intervertebral infections and was associated with fewer injuries, less pain, low cost, and low recurrence rate.

Clinical Outcomes at One-year Follow-up for Patients With Surgical Site Infection After Spinal Fusion

STUDY DESIGN

Retrospective case-control study.

OBJECTIVE

To compare health-related quality of life outcomes at one-year follow-up between patients who did and did not develop surgical site infection (SSI) after thoracolumbar spinal fusion.

SUMMARY OF BACKGROUND DATA

SSI is among the most common healthcare-associated complications. As healthcare systems increasingly emphasize the value of delivered care, there is an increased need to understand the clinical impact of SSIs.

MATERIALS AND METHODS

A retrospective 3:1 (control:SSI) propensity-matched case-control study was conducted for adult patients who underwent thoracolumbar fusion from March 2014 to January 2020 at a single academic institution. Exclusion criteria included less than 18 years of age, incomplete preoperative and one-year postoperative patient-reported outcome measures, and revision surgery. Continuous and categorical data were compared via independent t tests and χ 2 tests, respectively. Intragroup analysis was performed using paired t tests. Regression analysis for ∆ patient-reported outcome measures (postoperative minus preoperative scores) controlled for demographics. The α was set at 0.05.

RESULTS

A total of 140 patients (105 control, 35 SSI) were included in final analysis. The infections group had a higher rate of readmission (100% vs. 0.95%, P <0.001) and revision surgery (28.6% vs. 12.4%, P =0.048). Both groups improved significantly in Physical Component Score (control: P =0.013, SSI: P =0.039), Oswestry Disability Index (control: P <0.001, SSI: P =0.001), Visual Analog Scale (VAS) Back (both, P <0.001), and VAS Leg (control: P <0.001, SSI: P =0.030). Only the control group improved in Mental Component Score ( P <0.001 vs. SSI: P =0.228), but history of a SSI did not affect one-year improvement in ∆MCS-12 ( P =0.455) on regression analysis. VAS Leg improved significantly less in the infection group (-1.87 vs. -3.59, P =0.039), which was not significant after regression analysis (β=1.75, P =0.050).

CONCLUSION

Development of SSI after thoracolumbar fusion resulted in increased revision rates but did not influence patient improvement in one-year pain, functional disability, or physical and mental health status.

C-reactive protein to albumin ratio (CAR) in predicting surgical site infection (SSI) following instrumented posterior lumbar interbody fusion (PLIF)

Identification of novel markers would contribute to the individualised risk assessment and development of a risk prediction model. This study aimed to investigate the role of the C-reactive protein to albumin ratio (CAR) in predicting surgical site infection (SSI) following instrumented posterior lumbar interbody fusion (PLIF) of lumbar degenerative diseases. This study enrolled patients who underwent PLIF and instrumentation for treatment of lumbar degenerative diseases between 2015 and 2020. Electronic medical records were inquired for data collection, with follow-up register for identifying SSI cases. The optimal cut-off for CAR was determined by constructing the receiver operator characteristic (ROC) curve. Patients with high- or low-CAR value were compared using the univariate analyses, and the association between CAR and the risk of SSI was investigated using multivariate logistics regression analysis. A total of 905 patients were enrolled, twenty-nine (3.2%) had developed an SSI with 72.4% occurring during index hospitalisation, and 11 (1.2%) had deep and 18 (2.0%) superficial SSIs. An SSI was associated with additional 10.7 days of index total hospital stay (P = .001). The CAR was 0-5.43 (median, 0.05), and the optimal cut-off was 0.09 and area under the curve was 0.720 (P < .001). 336 (37.1%) patients had a CAR ≥0.09 and 22 (6.5%) developed an SSI, with a crude risk of 5.6 relative to those with a low CAR. The multivariate analyses showed CAR ≥0.09 was associated with 8.06-fold increased risk of SSI, together with diabetes (P = .018), while hypertension was identified as a protective factor (OR, 0.34; 95%CI, 0.11-1.00, P = .049). High CAR is found to significantly predict the incident SSI following instrumented PLIF of lumbar degenerative diseases, and can be considered as a useful index in practice only after it is verified by future high-level evidences.

The Impact of Surgical Site Infection on Patient Outcomes After Open Posterior Instrumented Thoracolumbar Surgery for Degenerative Disorders

BACKGROUND

Few reports in the literature have described the long-term outcome of postoperative infection from the patient perspective. The aim of the present study was to determine if complicated surgical site infection (SSI) affects functional recovery and surgical outcomes up to 2 years after posterior instrumented thoracolumbar surgery for the treatment of degenerative disorders.

METHODS

This retrospective cohort study involved patients who had been enrolled in a previous randomized controlled trial that examined antibiotic use for open posterior multilevel thoracolumbar or lumbar instrumented fusion procedures. In the present study, patients who had SSI (n = 79) were compared with those who did not (n = 456). Patient-reported outcome measures (PROMs) included the Oswestry Disability Index (ODI), leg and back pain scores on a numeric rating scale, Short Form-12 (SF-12) summary scores, and satisfaction with treatment at 1.5, 3, 6, 12, and 24 months. Surgical outcomes included adverse events, readmissions, and additional surgery.

RESULTS

The median time to infection was 15 days. Of the 535 patients, 31 (5.8%) had complicated infections and 48 (9.0%) had superficial infections. Patients with an infection had a higher body mass index (BMI) (p = 0.001), had more commonly received preoperative vancomycin (p = 0.050), were more likely to have had a revision as the index procedure (p = 0.004), had worse preoperative mental functioning (mental component summary score, 40.7 ± 1.6 versus 44.1 ± 0.6), had more operatively treated levels (p = 0.024), and had a higher rate of additional surgery (p = 0.001). At 6 months after surgery, patients who developed an infection scored worse on the ODI by 5.3 points (95% confidence interval [CI], 0.4 to 10.1 points) and had worse physical functioning by -4.0 points (95% CI, -6.8 to -1.2 points). Comparison between the groups at 1 and 2 years showed no difference in functional outcomes, satisfaction with treatment, or the likelihood of achieving the minimum clinically important difference (MCID) for the ODI.

CONCLUSIONS

SSI more than doubled the post-discharge emergency room visit and additional surgery rates. Patients with SSI initially (6 months) had poorer overall physical function representing the delay to recovery; however, the negative impact resolved by the first postoperative year.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Management and outcome of spinal implant-associated surgical site infections in patients with posterior instrumentation: analysis of 176 cases

PURPOSE

The management of implant-associated surgical site infections (SSI) in patients with posterior instrumentation is challenging. Evidence regarding the most appropriate treatment and the need for removal of implants is equivocal. We sought to evaluate the management and outcome of such patients at our institution.

METHODS

We searched our prospectively documented databases for eligible patients with posterior spinal instrumentation, excluding the cervical spine (January 2008-June 2018). Patient files were reviewed, demographic data and treatment details were recorded. Patient-reported outcome (PRO) was assessed with the Core Outcome Measures Index (COMI) preoperatively and postoperatively at 3 and 12 months.

RESULTS

A total of 170 patients underwent 210 revisions for 176 SSIs. Two-thirds presented within four weeks (105/176, 59.7%, median 22.5d, 7d-11.1y). The most common pathogens were Staphylococcus aureus (n = 79/210, 37.6%) and Staphylococcus epidermidis (n = 56/210, 26.7%). Debridement and implant retention was performed in 135/210 (64.3%) revisions and partial replacement in 62/210 (29.5%). In 28/176 SSI (15.9%), persistent infection required multiple revisions (≤ 4). Surgery was followed by intravenous and oral antimicrobial treatment (10-12w). In 139/176 SSIs (79%) with ≥ 1y follow-up, infection was cured in 115/139 (82.7%); relapse occurred in 9 (relapse rate: 5.1%). Two patients (1.4%) died. COMI decreased significantly (8.2 ± 1.5 vs. 4.8 ± 2.9, p < 0.0001) over 12 months. 72.7% of patients were (very) satisfied with their care.

CONCLUSION

Patients with SSI after posterior (thoraco-)lumbo(-sacral) instrumentation can be successfully treated in most cases with surgical and specific antibiotic treatment. An interdisciplinary approach is recommended. Loose implants should be replaced. In some cases, multiple revisions may be necessary. Patient outcomes were satisfactory.

Postoperative Management Strategy of Surgical Site Infection following Lumbar Dynesys Dynamic Internal Fixation

Aim

To research the incidence of surgical site infection (SSI) following lumbar Dynesys dynamic internal fixation and its management strategy.

Methods

We retrospectively analyzed all cases of lumbar Dynesys dynamic internal fixation performed from January 2010 to December 2019, and the data from patients with SSI were collected. The observational indicators included the incidence of SSI, general information of the patients, surgical details, inflammatory indicators, pathogenic bacteria, and treatment. SSI was defined as both early infection and delayed infection, and the cases were divided into Groups A and B, respectively. The relevant indicators and treatment were compared between the two groups.

Results

A total of 1125 cases of lumbar Dynesys dynamic internal fixation were followed up. Twenty-five cases of SSI occurred, and the incidence of SSI was 2.22% (25/1125). There were 14 cases of early infection (1.24%) and 11 cases of delayed infection (0.98%). Fourteen cases of early infection occurred 12.3 ± 8.3 days postoperatively (3–30), and 11 cases of delayed infection occurred 33.3 ± 18.9 months postoperatively (3–62). The inflammatory indicators of Group A were significantly higher than those of Group B (all P < 0.05), except for procalcitonin. The main infection site in Group A was located on the skin and subcutaneous tissue and around the internal instrument, while the main infection site in Group B was around the internal instrument. The main treatment for Group A was debridement and implant replacement, and the main treatment for Group B was implant removal. Summary. The incidence of SSI following lumbar Dynesys dynamic internal fixation was 2.22%, the incidence of early SSI was 1.24%, and the incidence of delayed SSI was 0.98%. If the main infection site of early infection is in the incision, debridement should be the main treatment method; if the infection site is around the internal fixation, implant replacement is recommended on the basis of debridement. Once delayed infection is diagnosed, implant removal is suggested.

Removal of instrumentation for postoperative spine infection: systematic review

OBJECTIVE

Currently, no consensus exists as to whether patients who develop infection of the surgical site after undergoing instrumented fusion should have their implants removed at the time of wound debridement. Instrumentation removal may eliminate a potential infection nidus, but removal may also destabilize the patient's spine. The authors sought to summarize the existing evidence by systematically reviewing published studies that compare outcomes between patients undergoing wound washout and instrumentation removal with outcomes of patients undergoing wound washout alone. The primary objectives were to determine 1) whether instrumentation removal from an infected wound facilitates infection clearance and lowers morbidity, and 2) whether the chronicity of the underlying infection affects the decision to remove instrumentation.

METHODS

PRISMA guidelines were used to review the PubMed/MEDLINE, Embase, Cochrane Library, Scopus, Web of Science, and ClinicalTrials.gov databases to identify studies that compared patients with implants removed and patients with implants retained. Outcomes of interest included mortality, rate of repeat wound washout, and loss of correction.

RESULTS

Fifteen articles were included. Of 878 patients examined in these studies, 292 (33%) had instrumentation removed. Patient populations were highly heterogeneous, and outcome data were limited. Available data suggested that rates of reoperation, pseudarthrosis, and death were higher in patients who underwent instrumentation removal at the time of initial washout. Three studies recommended that instrumentation be uniformly removed at the time of wound washout. Five studies favored retaining the original instrumentation. Six studies favored retention in early infections but removal in late infections.

CONCLUSIONS

The data on this topic remain heterogeneous and low in quality. Retention may be preferred in the setting of early infection, when the risk of underlying spine instability is still high and the risk of mature biofilm formation on the implants is low. However, late infections likely favor instrumentation removal. Higher-quality evidence from large, multicenter, prospective studies is needed to reach generalizable conclusions capable of guiding clinical practice.

Timing of Preoperative Surgical Antibiotic Prophylaxis After Primary One-Level to Three-Level Lumbar Fusion

OBJECTIVE

The purpose of this study was to examine the relationship between timing of preoperative surgical antibiotic prophylaxis and postoperative surgical site infections (SSIs) among patients with 1-level to 3-level lumbar fusion.

METHODS

Patients having undergone a primary 1-level to 3-level lumbar fusion at a single institution were allocated into 5 groups based on the time from preoperative antibiotic administration to incision (group A, 0-15 minutes; group B, 16-30 minutes; group C, 31-45 minutes; group D, 46-60 minutes; and group E, 61+ minutes). Timing of antibiotic administration as a continuous variable was also analyzed. All patients received irrigation with 3 L of normal saline containing bacitracin as well as local administration of vancomycin powder. SSIs were identified by the definition set forth by the 2017 Centers for Disease Control and Prevention guidelines.

RESULTS

Among 1131 patients, 27 (2.4%) were found to have an SSI. Compared with patients with antibiotic administration within 0-15 minutes before incision, patients with administration 61+ minutes before incision (group 4) had significantly higher odds of developing an SSI (P < 0.001). Patients had a 1.05-fold higher likelihood of infection for each additional minute delay of administration before incision (P < 0.001). Receiver operating characteristic analysis reported an area under the curve of 0.733 and 0.776 for time as a continuous and categorical variable, respectively. Age (P = 0.02), body mass index (P = 0.03), diabetes mellitus diagnosis (P = 0.04), and type of antibiotic (P = 0.004) were significant predictors of SSI.

CONCLUSIONS

Our results show that preoperative antibiotic administration beyond 1 hour in patients who have undergone lumbar fusion is associated with higher rates of SSI.

Antibacterial efficacy of quaternized chitosan coating on 3D printed titanium cage in rat intervertebral disc space

BACKGROUND CONTEXT

Infection around intervertebral fusion cages can be intractable because of the avascular nature of the intervertebral disc space. Intervertebral cages with antibacterial effects may be a method by which this complication can be prevented.

PURPOSE

To investigate the bacterial load on the antibacterial coating cages for spinal interbody fusion STUDY DESIGN: An experimental in vitro and in vivo study.

METHODS

Based on the micro-computed tomography (CT) data of rat caudal discs, mesh-like titanium (Ti) cages that anatomically fit into the discs were fabricated by three-dimensional (3D) printing. Additionally, an antibacterial coating was applied with quaternized chitosan (hydroxypropyltrimethyl ammonium chloride chitosan, HACC). In vitro release kinetics of the HACC was performed, and the antibacterial performance of the HACC-coated (Ti-HACC) cages (via inhibition zone assay, bacterial adhesion assay, and biofilm formation assay) was evaluated. Then, Ti-HACC- or noncoated (Ti) cages were implanted in the caudal discs of rats with bioluminescent Staphylococcus aureus. Bacterial survival was investigated using an in vivo imaging system (IVIS) on postoperative days 1, 3, and 5. On day 5, the infection-related changes (bone destruction and migration of cages) were assessed using micro-CT, and the healing status of the surgical wounds was also assessed. After the removal of the cages, the quantification of bacteria attached to the cages was obtained by IVIS. Histological evaluation was performed by hematoxylin and eosin staining and TRAP (tartrate-resistant acid phosphatase) staining.

RESULTS

Release kinetic analysis showed the sustained release of HACC over 3 days from Ti-HACC cages. Antibacterial effects of Ti-HACC cages were demonstrated in all in vitro assays. IVIS evaluation indicated that the in vivo implantation of Ti-HACC cages with S. aureus exhibited better wound healing, less infection-related changes on micro-CT, and reduced bacterial quantity in the extracted cages compared to Ti cages. Histological evaluation demonstrated an increased number of TRAP-positive osteoclasts and severe bone destruction in the rats treated with Ti cages.

CONCLUSIONS

We developed a novel antibacterial HACC-coated intervertebral cage that exhibited prominent antibacterial efficacy and prevented the structural damage caused by the infection in rat caudal discs.

CLINICAL SIGNIFICANCE

HACC-coated titanium intervertebral cages may be a promising option for preventing intractable postoperative infection in spinal interbody fusion surgery.

Outcomes of surgical site infections following spinal column trauma

BACKGROUND

Surgical site infections (SSI) are an undesirable outcome of spinal surgery for both the patient and healthcare system. To date, few studies have investigated the impact of SSI on patient-reported and clinical outcomes. Sepsis and readmission are potential sequelae of SSI, with sepsis potentially being life threatening. This study aimed to assess the association between SSI and patient outcomes in a spinal trauma cohort.

METHODS

Adult (16+ years) patients who underwent emergency spinal surgery due to trauma between January 2010 and December 2016 at a major trauma centre in Melbourne, Australia, were identified through the Victorian Orthopaedic Trauma Outcomes Registry. The presence of an SSI was abstracted from the electronic medical record and outcomes were compared between patients with and without an SSI. Clinical outcomes were obtained from the medical record, and patient-reported outcomes at 6 and 12 months were obtained from the Victorian Orthopaedic Trauma Outcomes Registry. Chi-squared tests were used to compare patient outcomes between groups.

RESULTS

Of the 458 included patients, 26 (5.7%) developed an SSI. Patient-reported outcomes at 6 and 12 months were not different between the groups. An SSI was associated with sepsis (χ² ₁ = 24.20, P < 0.01), readmission (χ² ₁ = 215.34, P < 0.01), revision surgery (χ² ₁ = 171.21, P < 0.01) and removal of implants (χ² ₁ = 4.31, P = 0.04) within 12 months of discharge.

CONCLUSION

These findings indicate that spine trauma SSIs are not associated with patient-reported outcomes and may not have lasting effects on patients. Larger studies are required to assess further follow-up and support our findings and possibly distinguish outcomes between superficial and deep SSI.

Does preventive care bundle have an impact on surgical site infections following spine surgery? An analysis of 9607 patients

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

The purpose was to analyze the effect of care bundle protocol on SSI in our institution. Postoperative surgical site infections (SSI) pose significant health burden. In spite of the use of prophylactic antibiotics, surgical advances and postoperative care, wound infection continues to affect patient outcomes after spine surgery.

METHODS

Retrospective analysis of 9607 consecutive patients who underwent spine procedures from 2014 to 2018 was performed. Preventive care bundle was implemented from January 2017 consisting of (a) preoperative bundle-glycemic control, chlorhexidine gluconate (CHG) bath, (b) intra-operative bundle-time specified antibiotic prophylaxis, CHG+ alcohol-based skin preparation (c) postoperative bundle-five moments of hand hygiene, early mobilization and bundle auditing. Patients operated from January 2017 were included in the post-implementation cohort and prior to that the pre-implementation cohort was formed. Data were drawn from weekly and yearly spine audits from the hospital infection committee software. Infection data were collected based on CDC criteria, further sub classification was done based on procedure, spinal disorders and spine level. Variables were analyzed and level of significance was set as < 0.05.

RESULTS

A total of 7333 patients met the criteria. The overall SSI rate decreased from 3.42% (131/3829) in pre-implementation cohort to 1.22% (43/3504, p = 0.0001) in post-implementation cohort (RR = 2.73, OR = 2.79). Statistically significant reduction was seen in all the groups (a) superficial and deep, (b) early and late and (c) instrumented and uninstrumented groups but was more pronounced in early (p = 0.0001), superficial (p = 0.0001) and instrumented groups (p = 0.0001). On subgroup analysis based on spine level and spinal disorders, significant reduction was seen in lumbar (p = 0.0001) and degenerative group (p = 0.0001).

CONCLUSIONS

Our study revealed significant reduction of SSI secondary to strict bundle adherence and monitored compliance compared to patients who did not receive these interventions.

LEVEL OF EVIDENCE

III.

Effects of Negative Pressure Wound Therapy on Wound Dehiscence and Surgical Site Infection Following Instrumented Spinal Fusion Surgery-A Single Surgeon's Experience

BACKGROUND

Incisional negative pressure wound therapy (NPWT) is used in many surgical specialties to prevent postoperative dehiscence and surgical site infections (SSIs). However, little is known about the role of incisional NPWT in spine fusion surgery. Therefore, we sought to report a single surgeon's experience using incisional NPWT and describe its effects on dehiscence and SSIs after instrumented spine surgery.

METHODS

We compared rates of hospital readmission and return to the operating room for dehiscence and SSIs in a consecutive series of patients who underwent spinal fusion surgery with or without NPWT from 2015 to 2018.

RESULTS

A total of 393 patients without and 76 patients with NPWT were included for analysis. Half way through the data collection period, all patients who underwent anterior lumbar fusion received NPWT. Three of 15 (20.0%) of non-NPWT patients who underwent anterior lumbar fusion had dehiscence or SSI compared with zero of 23 (0.0%) of NPWT patients (P = 0.01). NPWT for posterior surgeries was used on a case-by-case basis using risk factors that contribute to SSIs and dehiscence. NPWT patients had higher rates of spinal neoplasia (0.5% vs. 11.3%, P < 0.0001), osteomyelitis/diskitis (1.3% vs. 7.5%, P = 0.02), durotomy (14.9% vs. 28.6%, P = 0.007), revision surgery (32.2% vs. 59.6%, P = 0.0001), and longer fusion constructs (7 vs. 11 levels, P < 0.0001) but had similar rates of dehiscence and SSIs as non-NPWT patients (5.6% vs. 5.7%, P = 0.98).

CONCLUSIONS

NPWT decreases dehiscence and SSIs in patients undergoing lumbar fusion through an anterior approach. When preferentially used in patients at high risk for postoperative wound complications, NPWT prevents increased rates of dehiscence and SSI.

Global Treatment Outcome after Surgical Site Infection in Elective Degenerative Lumbar Spinal Operations

Background: Surgical site infection (SSI) is a serious complication after routine lumbar spinal operations, and its effect on global treatment outcome (GTO) is less reported. The aim of the current study was to measure the impact of SSI on outcome, which was evaluated with patient reported outcome measures (PROMs) and patients' subjective judgment (GTO). Methods: A total of 910 patients underwent primary a single- or two-level lumbar decompression or instrumented fusion surgical procedure. Patients completed Visual Analogue Scale (VAS), Oswestry Disability Index (ODI), and Core Outcome Measurement Index (COMI) at baseline and at two-year follow-up. The rate of improvement in PROMs was measured for the total cohort and the group of patients with SSI. Patients evaluated GTO on a five-point Likert scale. This study was approved by the Scientific and Research Ethics Committee of the Medical Research Council (number: 29970-3/2015/EKU) and the Institutional Review Board. Results: Regardless of the presence of SSI, significant improvement was measured in all PROMs without any difference in the rate of change between the clinical subgroups (non-SSI vs. SSI, dODI: p = 0.370, dCOMI: p = 0.383, dVAS: p = 0.793). In the total cohort, 87.3% of patients reported good outcome (N% = 87.3%). After an SSI, however, more patients (25.7%) reported poor outcome compared with those without the complication (chi-square test: value = 5.66; df = 1; p = 0.017; odds ratio = 2.49). Conclusions: Patients with successfully treated SSI can expect as good objective clinical result as patients without SSI while the subjective treatment outcome can be worse. The GTO could also be improved in complicated cases, however, with more extensive peri-operative patient education and information considering the patients' expectations, too.

Current Strategies in Prevention of Postoperative Infections in Spine Surgery

STUDY DESIGN

Narrative review.

OBJECTIVES

Postoperative surgical site infections (SSIs) are among the most common acute complications in spine surgery and have a devastating impact on outcomes. They can lead to increased morbidity and mortality as well as greater economic burden. Hence, preventive strategies to reduce the rate of SSIs after spine surgery have become vitally important. The purpose of this article was to summarize and critically analyze the available evidence related to current strategies in the prevention of SSIs after spine surgery.

METHODS

A literature search utilizing Medline database was performed. Relevant studies from all the evidence levels have been included. Recommendations to decrease the risk of SSIs have been provided based on the results from studies with the highest level of evidence.

RESULTS

SSI prevention occurs at each phase of care including the preoperative, intraoperative, and postoperative periods. Meticulous patient selection, tight glycemic control in diabetics, smoking cessation, and screening/eradication of Staphylococcus aureus are some of the main preoperative patient-related preventive strategies. Currently used intraoperative measures include alcohol-based skin preparation, topical vancomycin powder, and betadine irrigation of the surgical site before closure. Postoperative infection prophylaxis can be performed by administration of silver-impregnated or vacuum dressings, extended intravenous antibiotics, and supplemental oxygen therapy.

CONCLUSIONS

Although preventive strategies are already in use alone or in combination, further high-level research is required to prove their efficacy in reducing the rate of SSIs in spine surgery before evidence-based standard infection prophylaxis guidelines can be built.

Surgical Site Infection Prevention Following Spine Surgery

STUDY DESIGN

Literature review.

OBJECTIVES

Surgical site infection (SSI) following spine surgery leads to significant patient morbidity, mortality, and increased health care costs. The purpose of this article is to identify risk factors and strategies to prevent SSIs following spine surgery, with particular focus on avoiding infections in posterior cervical surgery.

METHODS

We performed a literature review and synthesis to identify methods that can be used to prevent the development of SSI following spine surgery. Specific pearls for preventing infection in posterior cervical spine surgery are also presented.

RESULTS

SSI prevention can be divided into patient and surgeon factors. Preoperative patient factors include smoking cessation, tight glycemic control, weight loss, and nutrition optimization. Surgeon factors include screening and treatment for pathologic microorganisms, skin preparation using chlorhexidine and alcohol, antimicrobial prophylaxis, hand hygiene, meticulous surgical technique, frequent irrigation, intrawound vancomycin powder, meticulous multilayered closure, and use of closed suction drains.

CONCLUSION

Prevention of SSI following spine surgery is multifactorial and begins with careful patient selection, preoperative optimization, and meticulous attention to numerous surgical factors. With careful attention to various patient and surgeon factors, it is possible to significantly reduce SSI rates following spine surgery.

Vancomycin powder for the prevention of surgical site infection in posterior elective spinal surgery

OBJECTIVE

To assess the effectiveness and safety of vancomycin powder as surgical site infection (SSI) prophylaxis in posterior bilateral elective spinal surgery.

MATERIALS AND METHODS

Single-center quasi-experimental pre and postintervention comparative cohort study. The post-intervention group received standard intravenous antibiotic prophylaxis plus 1g of vancomycin powder into the surgical field before wound closure, and the pre-intervention group only the intravenous prophylaxis.

RESULTS

150 patients were included in each group. Twelve SSI (7 superficial and 5 deep) occurred in the post-intervention group and 16 SSI (7 superficial and 9 deep) in the pre-intervention group. The risk of deep SSI decreased from 6.0% to 3.3% (OR 0,54, 95%CI 0.17-1.65, p=0.411) with vancomycin powder. The percentage of deep SSI due to gram negative-positive germs were 80%-20% and 33%-67% for the post- and pre-intervention groups, respectively (p=0.265). No local or systemic adverse effects occurred attributable to vancomycin powder.

CONCLUSION

In posterior elective spinal surgery, prophylaxis with vancomycin powder did not result in a significantly reduced incidence of superficial and deep SSI. There was a trend towards a higher incidence of deep SSI caused by gram negative microorganisms among those treated with vancomycin.

Application of Vancomycin Powder to Reduce Surgical Infection and Deep Surgical Infection in Spinal Surgery: A Meta-analysis

STUDY DESIGN

This was a meta-analysis study.

OBJECTIVE

Our meta-analysis study aimed to evaluate the efficacy of vancomycin powder to reduce the surgical site infection (SSI) in spinal surgery.

SUMMARY OF BACKGROUND DATA

The SSI is a potential and devastating complication after spinal surgery. Local application of vancomycin powder is an attractive adjunctive therapy to reduce SSI in spinal surgery.

METHODS

Studies were identified from PubMed, The Cochrane Library, AMED, Web of Science, Scopus, Ovid, EMBASE, and Ebsco Medline. The fixed-effects model was used to compute the merge of relative risk and 95% confidence interval (CI). Heterogeneity tests were checked by I statistics. Subgroup analysis was performed to determine whether vancomycin powder was beneficial, that could reduce the SSI in spinal surgery, or not. Publication bias was explored by funnel plot.

RESULTS

We included 21 studies for final analysis. In our analysis, application of vancomycin powder was associated with a significantly reduced risk of SSI and deep SSI. Pooled relative risks showed significant changes: SSI, 0.36 (95% CI: 0.27-0.47, P=0.000), SSI in the instrumented group, 0.35 (95% CI: 0.25-0.49, P=0.000), SSI in the noninstrumented group, 0.39 (95% CI: 0.24-0.65, P=0.000), deep SSI, 0.28 (95% CI: 0.18-0.44, P=0.000), and the incidence pseudoarthrosis, 0.88 (95% CI: 0.35-2.21, P=0.784). In the subgroup analysis, vancomycin powder showed beneficial effects to SSI in the instrumented group. Pooled the heterogeneity: SSI (P=0.124, I=30.0%), SSI in the instrumented group (P=0.366, I=8.2%), SSI in the noninstrumented group (P=0.039, I=60.5%), deep SSI (P=0.107, I=33.5%).

CONCLUSIONS

The application of vancomycin powder could decrease the SSI and deep SSI in spinal surgery. In the subgroup, vancomycin powder is beneficial to the SSI in the instrumented group. The available evidence is too limited to make the conclusion that the use of vancomycin powder causes pseudoarthrosis in spinal surgery, its extrapolation should be carefully executed.

Perioperative Invasive Vascular Catheterization Associated With Increased Risk of Postoperative Infection in Lumbar Spine Surgery: An Analysis of 114,259 Patient Records

STUDY DESIGN

This is a retrospective cohort study.

OBJECTIVE

This study's objective was to determine whether perioperative invasive vascular catheter placement, independent of comorbid conditions, modified the risk of postoperative infection in lumbar spine surgery.

SUMMARY OF BACKGROUND DATA

Infection is a risk inherent to lumbar spine surgery, with overall postoperative infection rates of 0.86%-8.5%. Patients experiencing postoperative infection have higher rates of mortality, revision surgeries, pseudarthrosis, and worsening pain and disability.

METHODS

Data were collected for patients undergoing lumbar spine surgery between January 2007 and October 2015 with records in the nationwide Humana private insurance database. Patients receiving fusion, laminectomy, and discectomy were followed for 3 months from the date of surgery for surgical site infection (SSI), 6 months for subsequent incision and drainage (I&D), and 1 year for vertebral osteomyelitis (VO). Risk factors investigated included central venous catheter and arterial-line placement.

RESULTS

Analysis of 114,259 patient records showed an overall SSI rate of 3.2% within 1 month and 4.5% within 3 months, overall vertebral osteomyelitis rate of 0.82%-0.83% within 1 year, and overall I&D rate of 2.8% within 6 months. Patients receiving a first-time invasive vascular catheter on the day of surgery were more likely to experience SSI within 1 month [risk ratios (RR), 2.5, 95% confidence interval (CI): 2.3-2.7], SSI within 3 months (RR, 2.4; 95% CI: 2.3-2.7), osteomyelitis within 1 year (RR, 4.2-4.3; 95% CI: 3.7-4.5), and undergo an I&D within 6 months (RR, 1.9; 95% CI: 1.8-2.0). These trends were consistent by procedure type and independent of the patient's weighted comorbidity index score (Charlson Comorbidity Index).

CONCLUSIONS

Perioperative invasive vascular catheterization was significantly associated with an increased the risk of postoperative infections in lumbar spine surgery, independent of a patient's concomitant comorbidities. Therefore, in patients with an indication for invasive catheterization, surgeons should consider risks and benefits of surgery carefully.

LEVEL OF EVIDENCE

Level III.

Management of late-onset deep surgical site infection after instrumented spinal surgery

Background

There are no universally accepted protocols for the treatment of late-onset deep surgical site infection. This study retrospectively evaluates the methods of aggressive debridement with instrumentation retention, high vacuum closed-suction drain without irrigation, primary wound closure, and antibiotic therapy for the treatment of late-onset deep surgical site infection after instrumented spinal surgery.

Methods

A total of 4057 patients who underwent instrumented spinal surgeries were surveyed from January 2010 to June 2014. Surgical debridement was performed immediately after late-onset deep surgical site infection was identified. In addition to extended resection of the devitalized and necrotic tissue, the biofilms adhered to the surface of implants were removed meticulously and thoroughly. Primary wound closure was performed on each patient, and closed suction drains were maintained for about 7–10 days without irrigation. Antibiotic therapy was administered for 3 months according to the results of the pathogenic culture.

Results

Forty-two patients were identified as having late-onset deep surgical site infection. Staphylococcus aureus was the most common pathogen in this group. Seven patients with late-onset deep surgical site infection had negative bacterial culture results. Infections resolved in all patients. Forty-one patients retained their instrumentation, whereas 1 patient had the implants removed because of Staphylococcus aureus infection, which was found the implants loosening during debridement. Primary wound healing was found in all patients with no recurrence of infection during the follow-up periods.

Conclusions

A timely diagnosis, aggressive and meticulous debridement, high vacuum closed-suction drain, routine and adequate use of antibacterial agents are the keys to successfully resolving infection and keeping implants retention in the treatment of late-onset deep surgical site infection after instrumented spinal surgery.

Vacuum-assisted closure combined with a closed suction irrigation system for treating postoperative wound infections following posterior spinal internal fixation

BACKGROUND

Wound infections after posterior spinal surgery are a troublesome complication; patients are occasionally forced to remove the internal fixation device, which can lead to instability of the spine and injury to the spinal cord. The purpose of this study was to evaluate the efficacy of modified vacuum-assisted closure (VAC) for treating an early postoperative spinal wound infection.

METHODS

We conducted a retrospective study of 18 patients with wound infections after posterior spinal surgery from 2014 to 2017 at a single tertiary center. All patients included in the study received modified VAC treatment (VAC combined with a closed suction irrigation system, CSIS) until the wound satisfied the secondary closure conditions. Detailed information was obtained from the medical records.

RESULTS

Wound size decreased significantly after 1 week of the modified VAC treatment. Three patients were treated with VAC three times and one patient received the VAC treatment four times; the remaining patients received the VAC treatment twice. The patients had excellent wound beds after an average of 8 days. The wound healed completely after an average of 17 days, and the average hospital stay was 33 days. There was no recurrence of infection at the 1-year follow-up.

CONCLUSIONS

This study demonstrates that VAC combined with a CSIS is a safe, reliable, and effective method to treat a wound infection after spinal surgery. This improved VAC procedure provides an excellent wound bed to facilitate wound healing and shorten the hospital stay.

Surgical Site Infections in Spine Surgery: Preoperative Prevention Strategies to Minimize Risk

STUDY DESIGN

Literature review.

OBJECTIVES

A review of the literature identifying preoperative risk factors for developing surgical site infections after spine surgery and discussion of the preventive strategies to minimize risks.

METHODS

A review of the literature and synthesis of the data to provide an updated review on the preoperative management of surgical site infection.

RESULTS

Preoperative prevention strategies of reducing surgical site infections in spine surgery remains a challenging problem. Careful mitigation of modifiable patient comorbidities, blood glucose control, smoking, obesity, and screening for pathologic microorganisms is paramount to reduce this risk. Individualized antibiotic regimens, skin preparation, and hand hygiene also play a critical role in surgical site infection prevention.

CONCLUSIONS

This review of the literature discusses the preoperative preventive strategies and risk management techniques of surgical site infections in spine surgery. Significant decreases in surgical site infections after spine surgery have been noted over the past decade due to increased awareness and implementation of the prevention strategies described in this article. However, it is important to recognize that prevention of surgical site infection requires a system-wide approach that includes the hospital system, the surgeon, and the patient. Continued efforts should focus on system-wide implementation programs including careful patient selection, individualized antibiotic treatment algorithms, identification of pathologic organisms, and preoperative decolonization programs to further prevent surgical site infections and optimize patient outcomes.

Risk factors for surgical site infection following lumbar spinal surgery: a meta-analysis

Objective

To identify risk factors for surgical site infection (SSI) in patients who had undergone lumbar spinal surgery.

Methods

Studies published in PubMed, Web of Science, and Embase were systematically reviewed to determine risk factors for SSI following lumbar spinal surgery. Results are expressed as risk ratios (RRs) with 95% CIs and weighted mean difference (WMD) with 95% CI. A fixed-effect or random-effect model was used to pool the estimates according to heterogeneity among the studies included.

Results

Sixteen studies involving 13,393 patients were included in this meta-analysis. Pooled estimates suggested that diabetes (RR 2.19, 95% CI 1.43–3.36; P<0.001), obesity (RR 2.87, 95% CI 1.62–5.09; P<0.001), BMI (WMD 1.32 kg/m², 95% CI 0.39–2.25; P=0.006), prolonged operating time (WMD 24.96 minutes, 95% CI 14.77–35.15; P<0.001), prolonged hospital stay (WMD 2.07 days, 95% CI 0.28–3.87; P=0.024), hypertension (RR 1.28, 95% CI 1.08–1.52; P=0.005), and previous surgery (RR 2.06, 95% CI 1.39–3.06; P<0.001) were independent risk factors for SSI in patients who had undergone lumbar spine surgery. Current smoking (RR 0.89, 95% CI 0.75–1.06; P=0.178), American Society of Anesthesiologists grade >2 (RR 2.63, 95% CI 0.84–8.27; P=0.098), increased age (WMD 1.43 years, 95% CI −1.15 to 4.02; P=0.278), COPD (RR 1.21, 95% CI 0.68–2.17; P=0.521), cardiovascular disease (RR 1.63, 95% CI 0.40–6.70; P=0.495), rheumatoid arthritis (RR 1.76, 95% CI 0.53–5.90; P=0.359), and osteoporosis (RR 1.91, 95% CI 0.79–4.63; P=0.152) were not risk factors for postoperative SSI.

Conclusion

Our results identified several important factors that increased the risk of postoperative SSI. Knowing these risk factors, surgeons could adequately analyze and evaluate risk factors in patients and then develop prevention measurements to reduce the rate of SSI.

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.

An Analysis of Implant Retention and Antibiotic Suppression in Instrumented Spine Infections: A Preliminary Data Set of 67 Patients

Background

It is unclear whether patients can be taken off suppressive antibiotics with infected retained instrumentation. This study aimed to retrospectively analyze the perioperative course and antibiotic regimen that led to the clinical intervention of patients with infected spinal instrumentation.

Methods

Consecutive adult patients with spine instrumentation who suffered surgical site infections (SSI) requiring debridement were retrospectively analyzed. The patients were grouped into 4 cohorts based on their clinical intervention: removal of instrumentation, reinstrumentation, retention of instrumentation with continued antibiotic suppression, and retention of instrumentation with no antibiotic suppression. Patient factors, infection factors, debridement, and antibiosis were compared.

Results

Of the 67 patients with SSI after spine surgery and instrumentation, 19 (28%) had their instrumentation removed, 6 (9%) had their instrumentation exchanged, 25 (37%) had their instrumentation retained and were on antibiotic suppression, and 17 (25%) had their instrumentation retained without any suppression. Those who had their instrumentation removed had a later presentation of their infection averaging 85 days (range 6-280 days) postoperatively. There was an earlier presentation for those who retained their implants, with suppression averaging 19 days (range 9-39) and no suppression averaging 29 days (range 6-90 days) post operatively (P < .001).

Conclusions

None of the patients with retained instrumentation without suppression had recurrence of infections after long-term follow-up. Lifelong antibiotic suppression may not be required with SSI that present early after early aggressive debridement. Patients with infections detected later are difficult to treat without removal of their original instrumentation.

Clinical Relevance

This study presents the outcomes of surgical and antibiotic factors in patients with infected spinal instrumentation.

A Retrospective Analysis of Deep Surgical Site Infection Treatment after Instrumented Spinal Fusion with the Use of Supplementary Local Antibiotic Carriers

Background: There is no generally established treatment algorithm for the management of surgical site infection (SSI) and non-union after instrumented spinal surgery. In contrast to infected hip- and knee- arthroplasties, the use of a local gentamicin impregnated carrier in spinal surgery has not been widely reported in literature.

Patients and methods: We studied 48 deep SSI and non-union patients after instrumented spine surgery, treated between 1999 and 2016. The minimum follow-up was 1.5 years. All infections were treated with a treatment-regimen consisting of systemic antibiotics and repetitive surgical debridement, supplemented with local gentamicin releasing carriers.

We analysed the outcome of this treatment regimen with regard to healing of the infection, as well as patient- and surgery-characteristics of failed and successfully treated patients.

Results: 42 of the 48 (87.5%) patients showed successful resolution of the SSI without recurrence with a stable spine at the end of treatment.

36 patients' SSI were treated with debridement, local antibiotics, and retention or eventual restabilization of the instrumentation in case of loosening. 3 patients were treated without local antibiotics because of very mild infection signs during the revision operation. 3 patients were treated with debridement, local antibiotics and removal of instrumentation. One of these patients was restabilized in a second procedure.

Infection persisted or recurred in 6 patients. These patients had a worse physical status with a higher ASA-score. Staphylococcus aureus was the most frequent causative microorganism.

Interpretation: Debridement and retention of the instrumentation, in combination with systemic antibiotics and the addition of local antibiotics provided a successful treatment for SSI and non-union after instrumented spinal fusion.

Surgical Infection after Posterolateral Lumbar Spine Arthrodesis: CT Analysis of Spinal Fusion

OBJECTIVE

To determine the incidence of infection after instrumented lumbar spine surgery, the demographic and surgical variables associated with acute infection, and the influence of infection and debridement on the consolidation of spinal fusion.

METHODS

After obtaining approval from the hospital ethics committee, an observational study was made on a prospective cohort of consecutive patients surgically treated by posterolateral lumbar spine arthrodesis (n = 139, 2005-2011). In all cases, the minimum follow-up period was 18 months. The following bivariate analysis was conducted of demographic and surgical variables: non-infection group (n = 123); infection group (n = 16). Fusion rates were determined by multislice CT. Logistic regression analysis was performed.

RESULTS

Incidence of deep infection requiring debridement: 11.51% (95% confidence interval, 5.85-17.18]). Bivariate analysis: differences were observed in hospital stay (7.0 days [range, 4-10] vs 14.50 days [range, 5.25-33.75]; P = 0.013), surgical time (3.15 h vs 4.09 h; P = 0.004), body mass index (25.11 kg/m² [22.58-27.0] vs 26.02 kg/m² [24.15 to 29.38]; P = 0.043), Charlson comorbidity index (median, 0 vs 1; P = 0.027), and rate of unsuccessful consolidation according to CT (18.4% vs 72.7%; P = 0.0001). In a model of multivariate logistic regression, taking as the dependent variable unsuccessful arthrodesis after 1 year, and adjusting for the other independent variables (infection, body mass index, Charlson comorbidity index, and surgical time), the only variable that was significantly associated with an outcome of unsuccessful spinal fusion after 1 year was infection, with OR = 12.44 (95% confidence interval, 2.50-61.76).

CONCLUSION

Deep infection after instrumented lumbar spine arthrodesis is a common complication that compromises the radiographic outcome of surgery. Patients who develop a postoperative infection and require debridement surgery are 12 times less likely to achieve satisfactory radiological fusion.

Use of intrawound vancomycin powder against postoperative infection after spine surgery

Local application of vancomycin has recently become widely used in spine surgery. However, local application is not included in the indication and has not been approved by the US Food and Drug Administration (FDA). Thus, we searched for reports with "intra wound-vancomycin" and "SSI" as keywords in the MEDLINE database, and investigated the efficacy, problems with use, and future prospects based on these reports. Intrawound vancomycin was described as effective in most of the reports, but was found to have no effect or to aggravate the condition in some reports. A toxic effect on osteoblasts due to a high local concentration was described in some reports, whereas local application was found to be safe in other studies. The amount of vancomycin used and the administration method varied among the reports. Overall, the results suggest that intrawound vancomycin is clinically effective, but this has yet to be established in a randomized controlled trial. There is a need to identify cases that should be selected for this treatment and to investigate the dose and optimum concentration of vancomycin for clinical use.

Presence of Modic type 1 change increases risk of postoperative pyogenic discitis following decompression surgery for lumbar canal stenosis

STUDY DESIGN

Multicenter retrospective study.

BACKGROUND

Postoperative surgical site infection is one of the most serious complications following spine surgery. Previous studies do not appear to have investigated pyogenic discitis following lumbar laminectomy without discectomy. This study aimed to identify risk factors for postoperative pyogenic discitis following lumbar decompression surgery.

METHODS

We examined data from 2721 patients undergoing lumbar laminectomy without discectomy in five hospitals from April 2007 to March 2012. Patients who developed postoperative discitis following laminectomy (Group D) and a 4:1 matched cohort (Group C) were included. Fisher's exact test was used to determine risk factors, with values of p < 0.05 considered statistically significant.

RESULTS

The cumulative incidence of postoperative discitis was 0.29% (8/2721 patients). All patients in Group D were male, with a mean age of 71.6 ± 7.2 years. Postoperative discitis was at L1/2 in 1 patient, at L3/4 in 3 patients, and at L4/5 in 4 patients. Except for 1 patient with discitis at L1/2, every patient developed discitis at the level of decompression. The associated pathogens were methicillin-resistant Staphylococcus aureus (n = 3, 37.5%), methicillin-susceptible Staphylococcus epidermidis (n = 1, 12.5%), methicillin-sensitive S. aureus (n = 1, 12.5%), and unknown (n = 3, 37.5%). In the analysis of risk factors for postoperative discitis, Group D showed a significantly lower ratio of patients who underwent surgery in the winter and a significantly higher ratio of patients who had Modic type 1 in the lumbar vertebrae compared to Group C.

CONCLUSIONS

Although further prospective studies, in which other preoperative modalities are used for the evaluation, is needed, our data suggest the presence of Modic type 1 as a risk factor for discitis following laminectomy. Latent pyogenic discitis should be carefully ruled out in patients with Modic type 1. If lumbar laminectomy is performed for such patients, more careful observation is necessary to prevent the development of postoperative discitis.

Prevention of Surgical Site Infection in Spine Surgery

BACKGROUND

Spine surgery is complicated by an incidence of 1% to 9% of surgical site infection (SSI). The most common organisms are gram-positive bacteria and are endogenous, that is are brought to the hospital by the patient. Efforts to improve safety have been focused on reducing SSI using a bundle approach. The bundle approach applies many quality improvement efforts and has been shown to reduce SSI in other surgical procedures.

OBJECTIVE

To provide a narrative review of practical solutions to reduce SSI in spine surgery.

METHODS

Literature review and synthesis to identify methods that can be used to prevent SSI.

RESULTS

SSI prevention starts with proper patient selection and optimization of medical conditions, particularly reducing smoking and glycemic control. Screening for staphylococcus organisms and subsequent decolonization is a promising method to reduce endogenous bacterial burden. Preoperative warming of patients and timely administration of antibiotics are critical to prevent SSI. Skin preparation using chlorhexidine and alcohol solutions are recommended. Meticulous surgical technique and maintenance of sterile techniques should always be performed. Postoperatively, traditional methods of tissue oxygenation and glycemic control remain essential. Newer wound care methods such as silver impregnation dressing and wound-assisted vacuum dressing are encouraging but need further investigation.

CONCLUSION

Significant reduction of SSIs is possible, but requires a systems approach involving all stakeholders. There are many simple and low-cost components that can be adjusted to reduce SSIs. Systematic efforts including understanding of pathophysiology, prevention strategies, and system-wide quality improvement programs demonstrate significant reduction of SSI.

Surgical Site Infections Caused by Methicillin-resistant Staphylococcus epidermidis After Spinal Instrumentation Surgery

STUDY DESIGN

Retrospective case series.

OBJECTIVE

To determine relevant demographics, clinical presentations, and outcomes of surgical site infections (SSIs) after spinal instrumentation (SI) surgery caused by methicillin-resistant Staphylococcus epidermidis (MRSE).

SUMMARY OF BACKGROUND DATA

This is the first study looking specifically at MRSE-related SSIs after SI surgery.

METHODS

We performed a retrospective review of patients with MRSE-related SSIs from 665 consecutive cases of SI surgery performed between 2007 and 2014 at our institution.

RESULTS

During the study period, SSIs occurred in 21 patients. MRSE was isolated from cultures obtained from surgical wounds in nine of the 21 patients (43%). There were four males and five females with a mean age of 63.9 ± 15.1 years. Six patients presented with inflammatory signs, such as wound drainage, pyrexia, erythema, and elevated C-reactive protein. Three patients did not have signs of infection, but had early implant failure, and were diagnosed by positive cultures collected at the time of revision surgery. The mean time from index surgery to the diagnosis of infection was 23.6 days (range, 7-88 days). In one patient, the implant was removed before antibiotic treatment was administered because of implant failure. Eight patients were managed with antibiotics and implant retention. During the follow-up period, MRSE-related SSIs in seven of the eight patients were resolved with implant retention and antibiotics without the need for further surgical intervention. One patient did not complete the antibiotic course because of side effects, and implant removal was required to control the infection.

CONCLUSION

Early detection, surgical debridement, and administration of appropriate antibiotics for a suitable duration enabled infection control without the need for implant removal in the treatment of MRSE-related SSI after SI surgery.

LEVEL OF EVIDENCE

4.

Is Intraoperative Local Vancomycin Powder the Answer to Surgical Site Infections in Spine Surgery?

STUDY DESIGN

This is a retrospective cohort comparative study of all patients who underwent instrumented spine surgery at a single institution.

OBJECTIVE

To compare the rate of surgical site infection (SSI) between the treatment (vancomycin) and the control group (no vancomycin) in patients undergoing instrumented spine surgery.

SUMMARY OF BACKGROUND DATA

SSI after spine surgery is a dreaded complication associated with increased morbidity and mortality. Prophylactic intraoperative local vancomycin powder to the wound has been recently adopted as a strategy to reduce SSI but results have been variable.

METHODS

In the present study, there were 117 (30%) patients in the treatment group and 272 (70%) patients in the comparison cohort. All patients received identical standard operative and postoperative care procedures based on protocolized department guidelines. The present study compared the rate of SSI with and without the use of prophylactic intraoperative local vancomycin powder in patients undergoing various instrumented spine surgery, adjusted for confounders.

RESULTS

The overall rate of SSI was 4.7% with a decrease in infection rate found in the treatment group (0.9% vs. 6.3%). This was statistically significant (P = 0.049) with an odds ratio of 0.13 (95% confidence interval 0.02-0.99). The treatment group had a significantly shorter onset of infection (5 vs. 16.7 days; P < 0.001) and shorter duration of infection (8.5 vs. 26.8 days; P < 0.001). The most common causative organism was Pseudomonas aeruginosa (35.2%). Patient diagnosis, surgical approach, and intraoperative blood loss were significant risk factors for SSI after multivariable analysis.

CONCLUSION

Prophylactic Intraoperative local vancomycin powder reduces the risk and morbidity of SSI in patients undergoing instrumented spine surgery. P. aeruginosa infection is common in the treatment arm. Future prospective randomized controlled trials in larger populations involving other spine surgeries with a long-term follow-up duration are recommended.

LEVEL OF EVIDENCE

3.