Postoperative infection treatment score for the spine (PITSS): construction and validation of a predictive model to define need for single versus multiple irrigation and debridement for spinal surgical site infection

Surgical strategies for spinal infections: A narrative review

The successful operative management of spinal infections necessitates a thoughtful approach. Ideal treatment combines the universal goals of any spine operation, which are decompression of the neural elements and stabilization of instability, with source control and eradication of infection. Techniques to treat infection have evolved independently and alongside advances in implant technology and surgical techniques. This review will seek to outline current thinking on approaches to both primary and secondary spinal infections.

Postoperative spine surgical site infections: high rate of failure of one-stage irrigation and debridement

BACKGROUND CONTEXT

Following spine surgery, postoperative surgical site infection (SSI) is a rare but potentially devastating complication. Previous studies have assessed risk factors for spine SSI and one aimed to develop risk stratification tool to assess management options, but this tool has not been externally validated or regularly used.

PURPOSE

The current study aimed to investigate the rate of SSI following elective spine surgery, surgical management pursued, and success of traditionally utilized one-stage of irrigation and debridement (I&D) with closure over drains.

STUDY DESIGN

Retrospective case-control study.

PATIENT SAMPLE

Adult, elective spine surgeries performed at a single academic institution between 2013 and 2021 were evaluated. Patients who developed SSI requiring surgical intervention were identified.

OUTCOME MEASURES

Those who underwent initial management with I&D and closure over drains were assessed for need of subsequent I&D (considered failure of initial infection management).

METHODS

Of spine surgeries meeting inclusion criteria, those with SSI were identified and management was characterized. For those who did and did not fail attempted one stage I&D with closure over drains, pre-operative and surgical variables from the index procedure as well as infection characteristics were assessed and compared with univariable and multivariable analyses.

RESULTS

Of 11,023 elective spine surgeries, SSI was identified for 76 (0.7%). For initial management, I&D with closure over drains was used for 66 (86.8%) while I&D and wound vacuum management was used 10 (13.2%). Failure of attempted one stage I&D (requiring subsequent I&D procedure) was identified for 18 (27% of those undergoing I&D and closure over drains). Of multiple patient, surgical, and infection characteristics, the only factor identified as independently predictive of one stage I&D failure was presence of bacteremia (odds ratio [OR] 38.3, p=0.0007). Within the sub-cohort of patients with bacteremia, failure of attempted one stage I&D was noted for 80%.

CONCLUSION

Less than one percent of a large cohort of patients undergoing spine surgery were found to develop SSIs. Of those undergoing attempted one stage I&D, most patient, surgical, and infection variables did not influence outcome of the intervention. However, those with bacteremia were at 38.3 times greater odds of failing attempted one-stage I&D. These results suggest considering delayed closure approaches in these cases.

Current Applications of Machine Learning for Spinal Cord Tumors

Spinal cord tumors constitute a diverse group of rare neoplasms associated with significant mortality and morbidity that pose unique clinical and surgical challenges. Diagnostic accuracy and outcome prediction are critical for informed decision making and can promote personalized medicine and facilitate optimal patient management. Machine learning has the ability to analyze and combine vast amounts of data, allowing the identification of patterns and the establishment of clinical associations, which can ultimately enhance patient care. Although artificial intelligence techniques have been explored in other areas of spine surgery, such as spinal deformity surgery, precise machine learning models for spinal tumors are lagging behind. Current applications of machine learning in spinal cord tumors include algorithms that improve diagnostic precision by predicting genetic, molecular, and histopathological profiles. Furthermore, artificial intelligence-based systems can assist surgeons with preoperative planning and surgical resection, potentially reducing the risk of recurrence and consequently improving clinical outcomes. Machine learning algorithms promote personalized medicine by enabling prognostication and risk stratification based on accurate predictions of treatment response, survival, and postoperative complications. Despite their promising potential, machine learning models require extensive validation processes and quality assessments to ensure safe and effective translation to clinical practice.

Changes of the microbiological spectrum and antibiotic resistance pattern in postoperative spinal implant infections with multiple culture-positive revision surgeries

BACKGROUND CONTEXT

In severe cases of postoperative spinal implant infections (PSII) multiple revision surgeries may be needed. Little is known if changes in the microbiological spectrum and antibiotic resistance pattern occur between revision surgeries.

PURPOSE

Analysis of the microbiological spectrum and antibiotic resistance pattern in patients with multiple revision surgeries for the treatment of PSII STUDY DESIGN: Retrospective database analysis.

PATIENT SAMPLE

Between 01/2011 and 12/2018, 103 patients underwent 248 revision surgeries for the treatment of PSII. Twenty patients (19.4%) who underwent multiple revision surgeries for PSII were included in this study.

OUTCOME MEASURES

Microbiological spectrum, antibiotic resistance pattern.

METHODS

A retrospective analysis of a prospectively maintained single center spine infection database was performed with a minimum follow-up of 3 years. Overall, 20 patients (six male/14 female) underwent 82 revisions for PSII (median 3; range 2-12). There were 55 of 82 (67.1%) procedures with a positive microbiological result. Microbiological analysis was performed on tissue and implant sonication fluid. Changes in microbial spectrum and antibiotic resistance pattern between surgeries were evaluated using Chi-Square and Fisher's exact test.

RESULTS

In total, 74 microorganisms (83.3% gram-positive; 10.8% gram-negative) were identified. The most common microorganisms were Staphylococcus epidermidis (18.9%) and Cutibacterium acnes (18.9%). All S. epidermidis identified were methicillin-resistant (MRSE). Overall, there were 15 of 55 (27.3%) polymicrobial infections. The microbiological spectrum changed in 57.1% (20/35) between the revision stages over the entire PSII period. In 42.9% (15/35) the microorganism persisted between the revision surgeries stages. Overall, changes of the antibiotic resistance pattern were seen in 17.4% (8/46) of the detected microorganisms, comparing index revision and all subsequent re-revisions. Moreover, higher resistance rates were found for moxifloxacin and for ciprofloxacin at first re-revision surgery compared with index PSII revision. Resistances against vancomycin increased from 4.5% (1/23) at index PSII revision to 7.7% (2/26) at first re-revision surgery.

CONCLUSIONS

Changes of the microbiological spectrum and the resistance pattern can occur in patients with severe PSII who require multiple revision surgeries. It is important to consider these findings in the antimicrobial treatment of PSII. The microbiological analysis of intraoperative tissue samples should be performed at every revision procedure for PSII.

Clinical Outcome of Postoperative Surgical Site Infection in Patients with Posterior Thoracolumbar and Lumbar Instrumentation

OBJECTIVE

Postoperative surgical site infection (SSI) is associated with greater rates of disability, especially in instrumented spinal surgeries. The management of implant-associated surgical site infections (SSI) is challenging. We analyzed the data from our hospital databases to assess the incidence and characteristics related to postoperative surgical site infection (SSI) after posterior thoracolumbar and lumbar instrumentation.

METHODS

Patient demographics, infection characteristics, details of treatment, and perioperative factors were reviewed (Jan 2010 to Dec 2020). The Oswestry disability index (ODI), Patient Health Questionnaire-9 (PHQ-9), and Visual Analog Scale (VAS) scores for back and leg pain were analyzed preoperatively and postoperatively until last follow-up.

RESULTS

Of the 27,881 procedures collected from the databases, 521 were diagnosed with SSI (1.8%), and 191(36.7%) received at least one revision surgery for SSI. Infection rate was significantly higher in patients with lumbar spinal stenosis than those with scoliosis or kyphosis (P<0.01). Methicillin-sensitive Staphylococcus aureus (43.4%) was the most commonly isolated pathogen. The rate of complication secondary to antibiotics treatment was 7.8%, and long-term antibiotic suppression was reported in 15.2% of patients. Instrumentation was retained in 175 patients (91.6%) and all SSIs were controlled without recurrence during the follow-up.

CONCLUSION

Analysis of 27,881 patients showed an average SSI rate of 1.8%. Patients with deep wound SSI can be successfully treated in most cases with retention of instrumentation. Early diagnosis, positive revision surgery with strict irrigation, thorough debridement, and a long-term course of antibiotics are critical for eradicating infection, retaining implants, decreasing morbidity, and achieving wound healing.

Predictive Factors for Successful Treatment of Deep Incisional Surgical Site Infections following Instrumented Spinal Surgeries: Retrospective Review of 1832 Cases

Background: Surgical site infection (SSI) is a major complication in spinal instrumentation that is often difficult to treat. The purpose of this study was to identify and determine prognostic indicators for successful treatment of spine instrumentation SSI. Methods: Retrospectively, spine surgery cases were examined on SSI diagnosis. Post-instrumentation SSI patients were categorized as “Successful” if SSI subsided after single debridement. Patients in whom SSI did not subsided and/or required removal of instrumentation were classified as “Challenging”. We investigated the relation of treatment outcomes to patients and treatment factors. Results: A total of 1832 spinal instrumentation cases were recognized with 44 (2.40%) SSI cases. White blood cell count, C-reactive protein (CRP) levels, causative bacteria (i.e., S. Aureus or MRSA), trauma injury, and early-stage antimicrobial agent sensitivity correlated with treatment prognosis. Multivariate analysis highlighted CRP levels and applying early-stage sensitive antibiotics as potential impactful predictive factors for successful treatment. Conclusions: Our results demonstrated that early selection of sensitive antimicrobial agents is critical and emphasizes the potential for early-stage classification methods such as Gram staining. Additionally, S. Aureus and MRSA SSI formed significantly more challenging infections to treat, thus requiring consideration when deciding on instrumentation retention. These factors offer promising aspects for further large-scale studies.

Revisionary soft tissue reconstruction of posterior midline defects after spinal surgery-plastic reconstructive options including perforator flaps

Background

Chronic prevertebral soft tissue defects with exposed metal hardware following spinal surgery represent a challenging complication. Frequently patients underwent multiple previous operations due to wound complications. Surrounding soft tissues are often compromised due to malperfusion, severe subcutaneous scarring, previous local advancement flaps and therefore impair stable wound closure.

Methods

Patients after spinal surgery who received complex soft tissue reconstructions between 2011 and 2015 were analyzed retrospectively. Patient`s age, risk factors, wound size, cause and defect location as well as complication rates were evaluated. A focus was set on therapeutic strategies and decision-making concerning reconstructive techniques.

Results

Fourteen patients receiving 27 pedicled and one free flap were included in the study. Patients mean age was 51.1 years, mean wound size was 144 cm². Defects were located in the lumbar spine [8], cervical spine [2] and thoracic spine [1], respectively. Three patients suffered from extensive defects affecting more than one area. Mean time of flap surgery was 213 minutes. Fifteen perforator-based flaps and 11 non-perforator (classic rotation-flaps), 1 pedicled and 1 free latissimus dorsi flap were used. In 9 patients (64.3%) different flaps had to be combined in a single-staged procedure due to large wounds. Implant material was removed completely in six patients (42.9%), whereas in five patients (35.7%) implants were replaced within the operation for soft tissue reconstruction. In three patients (21.4%) initial implant removal or replacement was not possible which leads to prolonged postoperative wound infections.

Conclusions

Most patients with exposed spinal hardware suffered from multiple comorbidities and showed a poor general condition. Due to the reduced soft tissue quality wound healing is significantly impaired. Exposed implant material should be replaced or removed when possible. Therefore, the complete armamentarium of plastic reconstructive techniques is required for wound closure. Today, perforator flaps play a prominent role due to the variability, excellent vascularization and sufficient subcutaneous filling capacities.

Involvement of L5-S1 level as an independent risk factor for adverse outcomes after surgical treatment of lumbar pyogenic spondylitis: A multivariate analysis

PURPOSE

To identify the independent risk factors for adverse outcomes and determine the effect of L5-S1 involvement on the outcome of surgical treatment of lumbar pyogenic spondylitis (PS).

METHODS

A retrospective analysis was performed for all consecutive patients who underwent surgery for lumbar PS between November 2004 and June 2020 at a single institution. The patients were divided into two groups based on the outcomes: good and adverse (treatment failure, relapse, or death). Treatment failure was defined as persistent or worsening pain with C-reactive protein (CRP) reduction less than 25% from preoperative measurement or requiring additional debridement. Relapse was defined as the reappearance of symptoms and signs with an elevated white blood cell count, erythrocyte sedimentation rate, and CRP after the first period of treatment. Binary logistic regression analyses were performed to identify the independent risk factors for adverse outcomes.

RESULTS

Twenty-four (21.2%) of the 113 patients were classified as having adverse outcomes: treatment failure, relapse, and death occurred in 15, 7, and 2 patients, respectively. The involvement of L5-S1 (adjusted odds ratio [aOR] = 6.561, P = 0.004), Methicillin-resistant Staphylococcus aureus (MRSA) infection (aOR = 6.870, P = 0.008), polymicrobial infection (aOR = 12.210, P = 0.022), and Charlson comorbidity index (CCI; P = 0.005) were identified as significant risk factors for adverse outcomes.

CONCLUSION

Involvement of L5-S1, MRSA, polymicrobial infection, and CCI were identified as independent risk factors for adverse outcomes after surgical treatment of lumbar PS. Because L5-S1 is anatomically demanding to access anteriorly, judicious access and thorough debridement are recommended in patients requiring anterior debridement of L5-S1.

Can natural language processing provide accurate, automated reporting of wound infection requiring reoperation after lumbar discectomy?

BACKGROUND

Surgical site infections are a major driver of morbidity and increased costs in the postoperative period after spine surgery. Current tools for surveillance of these adverse events rely on prospective clinical tracking, manual retrospective chart review, or administrative procedural and diagnosis codes.

PURPOSE

The purpose of this study was to develop natural language processing (NLP) algorithms for automated reporting of postoperative wound infection requiring reoperation after lumbar discectomy.

PATIENT SAMPLE

Adult patients undergoing discectomy at two academic and three community medical centers between January 1, 2000 and July 31, 2019 for lumbar disc herniation.

OUTCOME MEASURES

Reoperation for wound infection within 90 days after surgery METHODS: Free-text notes of patients who underwent surgery from January 1, 2000 to December 31, 2015 were used for algorithm training. Free-text notes of patients who underwent surgery after January 1, 2016 were used for algorithm testing. Manual chart review was used to label which patients had reoperation for wound infection. An extreme gradient-boosting NLP algorithm was developed to detect reoperation for postoperative wound infection.

RESULTS

Overall, 5,860 patients were included in this study and 62 (1.1%) had a reoperation for wound infection. In patients who underwent surgery after January 1, 2016 (n=1,377), the NLP algorithm detected 15 of the 16 patients (sensitivity=0.94) who had reoperation for infection. In comparison, current procedural terminology and international classification of disease codes detected 12 of these 16 patients (sensitivity=0.75). At a threshold of 0.05, the NLP algorithm had positive predictive value of 0.83 and F1-score of 0.88.

CONCLUSION

Temporal validation of the algorithm developed in this study demonstrates a proof-of-concept application of NLP for automated reporting of adverse events after spine surgery. Adapting this methodology for other procedures and outcomes in spine and orthopedics has the potential to dramatically improve and automatize quality and safety reporting.

Successful 6-Week Antibiotic Treatment for Early Surgical-site Infections in Spinal Surgery

BACKGROUND

The incidence of spinal surgical site infections (SSIs) remains stable at less than 10%. Surgical reinterventions may be hampered by decubitus, treatment-related adverse events, and cost. In the context of emergence of bacterial resistance, a short duration of antimicrobial treatment is of critical importance. If the duration of treatment for SSI is currently 12 weeks, the aim of our study was to assess the efficacy of an antimicrobial treatment shortened to 6 weeks.

METHODS

This prospective study was carried out from November 2014 to July 2016 in an 827-bed teaching hospital. After surgical management of SSIs, patients received broad-spectrum antibiotics intravenously for 10 days and orally for the remainder, for a total of 6 weeks. Success was defined as absence of relapse, superinfection, or surgical failure at the end of treatment and at 1-year follow-up.

RESULTS

Eighty-five patients were included in this study. The median delay between initial surgery and diagnosis of SSI was 16 days. In 65 cases (76.4%), SSIs were monomicrobial; among these, Staphylococcus aureus was found in 30 cases (46%). Failure was observed in 7 cases (8.2%), with more than half caused by anaerobic bacteria.

CONCLUSIONS

Surgical management of SSI followed by a 6-week antibiotic treatment is associated with favorable outcome. Anaerobic bacteria seem to play a role in the occurrence of relapses. A 6-week reduction in antibiotic treatment leads to reduction in cost and, likely, also to reduction in the emergence and spread of resistant microorganisms.

Effectiveness of silver alloy-coated silicone urinary catheters in patients with acute traumatic cervical spinal cord injury: Results of a quality improvement initiative

Patients with acute traumatic cervical spinal cord injury (ATCSCI) have an increased risk of catheter-associated urinary tract infection (CAUTI). The effectiveness of silver alloy-coated silicone urinary catheters (SACC) in preventing CAUTI in ATCSCI is unknown and was the objective of this study. We performed a quality improvement initiative in an attempt to reduce CAUTI in patients undergoing spine surgery at a single quaternary center. Prior to July 2015, all patients received a latex indwelling catheter (LIC). All patients with ATCSCI with limited hand function (AIS A,B, or C) received a SACC. Incidence of CAUTI, microbiology, duration of infection, antibiotic susceptibility, and catheter-associated adverse events were recorded prospectively. We studied 3081 consecutive patients over the three years, of whom 302 (9.8%) had ATCSCI; 63% of ATCSCI patients were ASIA Impairment Scale (AIS) A or B. The overall rate of CAUTI was 19% (585/3081), and was 38% (116/302) in patients with ATCSCI. Of 178 ATCSCI patients with LIC, 100 (56%) developed a CAUTI compared with 28 of 124 (23%) patients with SACC (p < 0.05). Poly-microbial and gram-positive infection was more common in LIC than in SACC (p < 0.05). Median duration of infection was 9 days in SACC group and 12 days in LIC group (p = 0.08). Resistance to trimethoprim (p < 0.001) and ciprofloxacin (p < 0.05) were more common in LIC group. There was no difference in catheter-associated adverse events or length of stay between the groups. This quality improvement initiative illustrates the effectiveness of antiseptic silver alloy-coated silicone urinary catheters in patients with ATCSCI. In our population, the use of SACC reduces the incidence and the complexity of CAUTI.

Consensus on Implants in Infections After Spine Surgery

In July of 2018, the Second International Consensus Meeting (ICM) on Musculoskeletal Infection convened in Philadelphia, PA was held to discuss issues regarding infection in orthopedic patients and to provide consensus recommendations on these issues to practicing orthopedic surgeons. During this meeting, attending delegates divided into subspecialty groups to discuss topics specifics to their respective fields, which included the spine. At the spine subspecialty group meeting, delegates discussed and voted upon the recommendations for 63 questions regarding the prevention, diagnosis, and treatment of infection in spinal surgery. Of the 63 questions, 9 focused on implants questions in spine surgery, for which this article provides the recommendations, voting results, and rationales.

Chlorhexidine Showers are Associated With a Reduction in Surgical Site Infection Following Spine Surgery: An Analysis of 4266 Consecutive Surgeries

BACKGROUND

Surgical site infection (SSI) is a common complication following spinal surgery. Prevention is critical to maintaining safe patient care and reducing additional costs associated with treatment.

OBJECTIVE

To determine the efficacy of preoperative chlorhexidine (CHG) showers on SSI rates following fusion and nonfusion spine surgery.

METHODS

A mandatory preoperative CHG shower protocol was implemented at our institution in November 2013. A cohort comparison of 4266 consecutive patients assessed differences in SSI rates for the pre- and postimplementation periods. Subgroup analysis was performed on the type of spinal surgery (eg, fusion vs nonfusion). Data represent all spine surgeries performed between April 2012 and April 2016.

RESULTS

The overall mean SSI rate was 0.4%. There was no significant difference between the pre- (0.7%) and postimplementation periods (0.2%; P = .08). Subgroup analysis stratified by procedure type showed that the SSI rate for the nonfusion patients was significantly lower in the post- (0.1%) than the preimplementation group (0.7%; P = .02). There was no significant difference between SSI rates for the pre- (0.8%) and postimplementation groups (0.3%) for the fusion cohort (P = .21). In multivariate analysis, the implementation of preoperative CHG showers were associated with significantly decreased odds of SSI (odds ratio = 0.15, 95% confidence interval [0.03-0.55], P < .01).

CONCLUSION

This is the largest study investigating the efficacy of preoperative CHG showers on SSI following spinal surgery. In adjusted multivariate analysis, CHG showering was associated with a significant decrease in SSI following spinal surgery.

Short postsurgical antibiotic therapy for spinal infections: protocol of prospective, randomized, unblinded, noninferiority trials (SASI trials)

BACKGROUND

There are several open scientific questions regarding the optimal antibiotic treatment of spinal infections (SIs) with or without an implant. The duration of postsurgical antibiotic therapy is debated.

METHODS

We will perform two unblinded randomized controlled trials (RCTs). We hypothesize that shorter durations of systemic antibiotic therapy after surgery for SI are noninferior (10% margin, 80% power, α = 5%) to existing (long) treatment durations. The RCTs allocate the participants to two arms of 2 × 59 episodes each: 3 vs. 6 weeks of targeted postsurgical systemic antibiotic therapy for implant-free SIs or 6 vs. 12 weeks for implant-related SIs. This equals a total of 236 adult SI episodes (randomization scheme 1:1) with a minimal follow-up of 12 months. All participants receive concomitant multidisciplinary surgical, re-educational, internist, and infectious disease care. We will perform three interim analyses that are evaluated, in a blinded analysis, by an independent study data monitoring committee. Besides the primary outcome of remission, we will also assess adverse events of antibiotic therapy, changes of the patient's nutritional status, the influence of immune suppression, total costs, functional scores, and the timely evolution of the (surgical) wounds. We define infection as the presence of local signs of inflammation (pus, wound discharge, calor, and rubor) together with microbiological evidence of the same pathogen(s) in at least two intraoperative samples, and we define remission as the absence of clinical, laboratory, and/or radiological evidence of (former or new) infection.

DISCUSSION

Provided that there is adequate surgical debridement, both RCTs will potentially enable prescription of less antibiotics during the therapy of SI, with potentially less adverse events and reduced overall costs.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04048304. Registered on 5 August 2019.

PROTOCOL VERSION

2, 5 July 2019.

What Factors Predict Failure of Nonsurgical Management of a Lumbar Surgical Site Infection?

Background

One of the most frequent complications of invasive lumbar spine surgery is postoperative surgical site infections (SSIs). Although there are absolute criteria for surgical intervention (progressive neurologic deficit, sepsis, failure of medical management), the treatment of routine, uncomplicated SSIs remains somewhat unclear. The purpose of this study was to evaluate the outcome of a series of patients with postoperative surgical site infections who were treated with or without surgical intervention. The primary clinical outcome was the assessment of whether medical management alone would be sufficient to eradicate the infection.

Methods

A retrospective review of consecutive patients who underwent lumbar surgery complicated by spine infection between 2011 and 2017 was performed in order to determine what factors, if any, resulted in the need for additional surgical management. Medical records were reviewed for various demographic (e.g., age), clinical (e.g., organism), and surgical (e.g., presence of instrumentation) factors. A regression analysis was performed to identify what variables significantly increased the risk for SSI.

Results

During the 6-year period studied, a total of 74 patients met the inclusion criteria and were included in the study. There were 13 patients who failed medical management and required additional surgical management, which included irrigation and debridement. Thus, overall, medical management alone was effective in 82% of patients. In the final multivariate logistic regression analysis model, revision primary surgery had the strongest association with SSI that would require a washout. In addition, diabetes had a strong association with the occurrence of an infection.

Conclusions

Identification of risk factors associated with the need for additional surgical management may benefit from aggressive antibiotic therapy to reduce the likelihood of reoperation. Clinicians should be aware of the identified risk factors, which may help with postoperative management in at-risk individuals.

Comparison of pyogenic postoperative and native vertebral osteomyelitis

BACKGROUND CONTEXT

Postoperative vertebral osteomyelitis (PVO) after spinal surgery is a clinical challenge. However, there is a paucity of evidence regarding the most likely etiologic organisms to guide the choice of empirical antibiotic therapy, and previous reports of treatment outcomes for PVO are scarce.

PURPOSE

To compare the microbiology, clinical characteristics, and outcomes of pyogenic PVO with native vertebral osteomyelitis (NVO).

STUDY DESIGN

Retrospective comparative study.

PATIENT SAMPLE

Patients with microbiologically proven vertebral osteomyelitis from three university-affiliated hospitals in South Korea between January 2005 and December 2015 with follow-up of at least 12 months after completion of antibiotics or until the patient was transferred. Patients who had a spine operation in the same location within 1 year of diagnosis, and all patients with remnant implants at the time of the vertebral osteomyelitis diagnosis, were defined as having PVO. The remainder of the patients was considered to have NVO. Spinal operations included discectomy, laminectomy, arthrodesis, and instrumentation for stabilization of the spine.

OUTCOME MEASURES

Overall mortality, neurologic outcomes, treatment failure, and relapse of infection.

METHODS

Demographic data, comorbidities, presenting symptoms, microbiological data, radiographic characteristics, laboratory data (including white blood cell counts, erythrocyte sedimentation rate, and C-reactive protein), surgical treatment, and neurologic outcomes for each patient were reviewed from electronic medical records and analyzed. Mortality rate, treatment failure, and relapse of infection were calculated for the two groups. Factors associated with treatment outcome were evaluated using univariate and multivariate logistic regression analyses.

RESULTS

The study evaluated 104 patients with PVO and 441 patients with NVO. In PVO, the most common isolate was Staphylococcus aureus (34%, n=35), followed by coagulase-negative staphylococci (31%, n=32). In NVO, the most common isolates were S. aureus (47%, n=206) and streptococci (21%, n=94). Of the staphylococci, the proportion of methicillin-resistant strains was significantly higher in PVO than that in NVO (75% vs. 39%, p<.001). The proportion of patients with gram-negative bacilli was 14% in PVO and 20% in NVO. Pre-existing or synchronous nonspinal infection was observed more frequently in NVO than in PVO (33% vs. 13%, p<.001). Although the duration of antibiotic use was similar in both groups, surgery for infection control was performed more frequently in PVO. The mortality rate was similar in both groups. However, the treatment failure and relapse rates at 12 months were higher in the PVO group (23% vs. 13%, p=.009; 14% vs. 7%, p=.028, respectively). Methicillin-resistant S.aureus was significantly associated with treatment failure or relapse via logistic regression (odds ratio 3.01, 95% confidence interval [1.71-5.32], p<.001; odds ratio 2.78, 95% confidence interval [1.40-5.49], p=.003).

CONCLUSIONS

Coverage of methicillin-resistant staphylococci should be considered when prescribing empirical antibiotics for PVO. Although surgery was performed more often in PVO than NVO, the treatment failure and relapse rates at 12 months were higher in PVO.

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.

Strategies for the Prevention and Treatment of Surgical Site Infection in the Lumbar Spine

Surgical site infection (SSI) following spine surgery can be devastating for both the patient and the surgeon. It leads to significant morbidity and associated health care costs, from readmissions, reoperations, and subsequent poor clinical outcomes. Complications associated with SSI following spine surgery include pseudarthrosis, neurological deterioration, sepsis, and death. Its management can be very challenging. The diagnosis of SSI involves the interpretation of combined clinical, laboratory, and occasionally radiologic findings. Most infections can be treated with an appropriate course of antibiotics and bracing if required. Surgical intervention is usually reserved for infections resistant to medical management, the need for open biopsy/culture, evolving spinal instability or deformity, and neurologic deficit or deterioration. A thorough knowledge of associated risk factors is required and patients should be stratified for risk preoperatively. The multifaceted approach of risk stratification, early diagnosis and effective treatment, is essential for successful prevention and effective treatment and crucial for a satisfactory outcome.

Surgical site infection in spinal metastasis: incidence and risk factors

BACKGROUND

Surgical site infection (SSI) in spinal metastasis surgery represents the most common postoperative surgical complication with high morbidity and mortality.

OBJECTIVE

This study aims to evaluate the incidence of SSI in spinal metastasis surgery and its risk factors.

STUDY DESIGN

This is a retrospective analysis of a prospectively collected data.

METHODS

Preoperative, operative, and postoperative data were collected together with the modified Tokuhashi score and Frankel score at all time checkpoints. Surgical site infection was divided into superficial and deep SSI, as well as early (<90 days) and late SSI. Multiple logistic regression analysis was performed to identify independent risk factors, with p<.05 as significance threshold.

RESULTS

A total of 297 patients were included, with an incidence of SSI of 5.1% (superficial SSI: 3.4%; deep SSI: 1.7 %). Cervicothoracic surgery was associated with the highest incidence of SSI, whereas cervical surgery had the lowest incidence. Smoking, higher number of spinal metastasis, elevated body mass index (BMI), and higher ASA (American Society of Anesthesiologist) score were the preoperative factors associated with increased risk of SSI. Increased intraoperative blood loss and increased number of fixed vertebra increased the SSI incidence. SSI increased hospital stay by a mean of 12 days. When all these variables are analyzed in a multiple regression model, only surgical time≥4 hours and ASA≥3 were found to be independent risk factors for the occurrence of SSI.

CONCLUSION

This paper represents the largest series of spinal metastasis with a mean incidence of SSI of 5.1%. Smoking, higher BMI, higher number of spinal metastasis, higher ASA score, higher number of fused vertebra, intraoperative bleeding≥2000 mL, and neurologic deterioration are risk factors for SSI occurrence. Only ASA≥3 and operative duration≥4 hours are independent risk factors for this complication occurrence. Finally, SSI occurrence is associated with increased hospital stay, increased 30-day mortality rate, and decreased survival rates.

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.

The Effect of Postoperative Spinal Infections on Patient Mortality

STUDY DESIGN

A retrospective, matched cohort study.

OBJECTIVES

This study aims to investigate the association between surgical site infection (SSI) and mortality and ascertain any factors that predict mortality in those diagnosed with SSI.

SUMMARY OF BACKGROUND DATA

Despite significant efforts toward mitigation, SSI, including deep infection, remains a common complication following spine surgery, Considerable morbidity may be associated with infection, including hospital readmission, revision surgery, and delayed rehabilitation. However, it is not known whether this increase in morbidity is associated with increased mortality.

METHODS

Patients from a single center requiring reoperation for SSI following elective spine surgery between 2005 and 2013 were identified in a retrospective fashion. These patients were then matched one-to-three with patients undergoing elective spine surgery without SSI. Patients were matched for age, gender, body mass index (BMI), Charlson comorbidity index, year of surgery, spine region, and approach. The Social Security Death Index was utilized to identify deceased patients and their time of death. Univariate statistics were then utilized to compare mortality rates between the two groups. In addition, the SSI cohort was evaluated for predictors of mortality following SSI.

RESULTS

One-hundred ninety-five patients developed SSI at a mean of 27.4 (range: 1-467) days from the index surgery. Ninety-day, 1-year, 2-year, and 5-year mortality rates were 1.54% versus 1.03% (P = 0.70), 4.62% versus 1.2% (P = 0.006), 7.73% versus 2.25% (P = 0.001), and 15.45% versus 3.43% (P = 0.0002) for SSI versus control patients, respectively. Predictors of 2-year mortality in the SSI cohort were increased age (P = 0.02) and increased Charlson Comorbidity Index (P < 0.001). Region and approach of surgery, days to infection, and reason for elective surgery did not influence mortality.

CONCLUSION

SSI results in significant morbidity in the postoperative period, with the risk of reoperation, prolonged hospitalization, and need for other invasive procedures. In addition, this study provides evidence that SSI is associated with an increased mortality following elective spine surgery.

LEVEL OF EVIDENCE

4.

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.

Management of spinal infections in children with cerebral palsy

Cerebral palsy patients who undergo posterior spinal instrumentation for scoliosis are at a greater risk of surgical site infection compared to adolescents with idiopathic scoliosis. Many infecting organisms are reported. Risk factors include patients' specific factors, nutritional status as well as surgery related factors. Although surgical management is still controversial, it is always based on irrigation and debridement followed or not by implant removal. The purpose of this paper is to review the pathophysiology of surgical site infection in this patient population and to propose a treatment algorithm, based on a thorough review of the current literature and personal experience.

Risk factors for unavoidable removal of instrumentation after surgical site infection of spine surgery: A retrospective case-control study

Surgical site infection (SSI) after spine instrumentation is difficult to treat, and often requires removal of instrumentation. The removal of instrumentation after spine surgery is a severe complication that can lead to the deterioration of activities of daily living and poor prognosis. Although there are many reports on SSI after spine surgery, few reports have investigated the risk factors for the removal of instrumentation after spine surgery SSI. This study aimed to identify the risk factors for unavoidable removal of instrumentation after SSI of spine surgery. We retrospectively reviewed 511 patients who underwent spine surgery with instrumentation at Kagoshima University Hospital from January 2006 to December 2014. Risk factors associated with SSI were analyzed via multiple logistic regression analysis. Parameters of the group that needed instrumentation removal were compared with the group that did not require instrumentation removal using the Mann-Whitney U and Fisher's exact tests. The posterior approach was used in most cases (453 of 511 cases, 88.6%). SSI occurred in 16 of 511 cases (3.14%) of spine surgery with instrumentation. Multivariate logistic regression analysis identified 2 significant risk factors for SSI: operation time, and American Society of Anesthesiologists physical status classification ≥ 3. Twelve of the 16 patients with SSI (75%) were able to keep the instrumentation after SSI. Pseudarthrosis occurred in 2 of 4 cases (50%) after instrumentation removal. Risk factors identified for instrumentation removal after spine SSI were a greater number of past surgeries, low preoperative hemoglobin, high preoperative creatinine, high postoperative infection treatment score for the spine, and the presence of methicillin-resistant Staphylococcus aureus. In these high risk cases, attempts should be made to decrease the risk factors preoperatively, and careful postoperative monitoring should be conducted.

Variables associated with remission in spinal surgical site infections

BACKGROUND

There is few medical literature regarding factors associated with remission after surgical and medical treatment of postoperative spine infections.

METHODS

Single-centre case-control study 2007-2014. Cluster-controlled Cox regression model with emphasis on surgical and antibiotic-related parameters.

RESULTS

Overall, we found 66 episodes in 48 patients (49 episodes with metalwork) who had a median follow-up of 2.6 years (range, 0.5 to 6.8 years). The patients had a median of two surgical debridements. The median duration of antibiotic therapy was 8 weeks, of which 2 weeks parenteral. Clinical recurrence after treatment was noted in 13 episodes (20%), after a median interval of 2 months. In 53 cases (80%), the episodes were considered as in remission. By multivariate analyses, no variable was associated with remission. Especially, the following factors were not significantly related to remission: number of surgical interventions [hazard ratio (HR) 0.9; 95% confidence interval (CI), 0.8-1.1]; infection due to Staphylococcus aureus (HR 0.9; 0.8-1.1), local antibiotic therapy (HR 1.2; 0.6-2.4), and, duration of total (HR 1.0; 0.99-1.01) (or just parenteral) (HR 1.0; 0.99-1.01) antibiotic use.

CONCLUSIONS

In patients with post-operative spine infections, remission is achieved in 80%. The number of surgical debridement or duration of antibiotic therapy shows no association with recurrence, suggesting that individual risk factors might be more important than the duration of antibiotic administration.

A comparison of the Wiltse versus midline approaches in degenerative conditions of the lumbar spine

OBJECTIVE The objective of this study was to determine if there is a significant difference in surgical site infection (SSI) when comparing the Wiltse and midline approaches for posterior instrumented interbody fusions of the lumbar spine and, secondarily, to evaluate if the reoperation rates and specific causes for reoperation were similar for both approaches. METHODS A total of 358 patients who underwent 1- or 2-level posterior instrumented interbody fusions for degenerative lumbar spinal pathology through either a midline or Wiltse approach were prospectively followed between March 2005 and January 2011 at a single tertiary care facility. A retrospective analysis was performed primarily to evaluate the incidence of SSI and the incidence and causes for reoperation. Secondary outcome measures included intraoperative complications, blood loss, and length of stay. A matched analysis was performed using the Fisher's exact test and a logistic regression model. The matched analysis controlled for age, sex, comorbidities, number of index levels addressed surgically, number of levels fused, and the use of bone grafting. RESULTS All patients returned for follow-up at 1 year, and adverse events were followed for 2 years. The rate of SSI was greater in the midline group (8 of 103 patients; 7.8%) versus the Wiltse group (1 of 103 patients; 1.0%) (p = 0.018). Fewer additional surgical procedures were performed in the Wiltse group (p = 0.025; OR 0.47; 95% CI 0.23-0.95). Proximal adjacent segment failure requiring reoperation occurred more frequently in the midline group (15 of 103 patients; 14.6%) versus the Wiltse group (6 of 103 patients; 5.8%) (p = 0.048). Blood loss was significantly lower in the Wiltse group (436 ml) versus the midline group (703 ml); however, there was no significant difference between the 2 groups in intraoperative complications or length of stay. CONCLUSIONS The patients who underwent the Wiltse approach had a decreased risk of wound breakdown and infection, less blood loss, and fewer reoperations than the midline patients. The risk of adjacent segment failure in short posterior constructs is lower with a Wiltse approach.

Variation in the management of thoracolumbar trauma and postoperative infection

STUDY DESIGN

Multinational survey of spine trauma surgeons.

OBJECTIVES

To survey spine trauma surgeons, examine the variety of management practices for thoracolumbar fractures, and investigate the need for future areas of study.

BACKGROUND

Attempts to develop a universal thoracolumbar classification system represent the first step in standardizing treatment of thoracolumbar injuries, but there is little consensus regarding diagnosis and management of these injuries.

METHODS

A survey questionnaire regarding a fictional neurologically intact patient with a burst fracture was administered to 46 spine surgeons. The questionnaire consisted of 2 domains: management of thoracolumbar fractures and management of postoperative infection. Survey results were compiled and evaluated and consensus arbitrarily assumed when the majority of surgeons agreed on a single question answer.

RESULTS

Although majority consensus was reached on most questions, the interobserver reliability was poor. Consensus was achieved that magnetic resonance imaging should be performed during initial imaging. The majority would also operate regardless of magnetic resonance imaging findings, and would not operate at night. The favored technique was a posterior approach with decompression. Percutaneous fusion was considered a viable option by the majority of surgeons. No consensus was reached regarding instrumentation levels or construct length. The majority would use posterolateral bone grafting, and would not remove instrumentation nor perform an anterior reconstruction. Consensus was reached that postoperative bracing is unnecessary. Regarding management of infection, consensus was reached to use intraoperative vancomycin powder but not culture the nares before surgery. The majority used a set time period for antibiotic treatment when a drain was required, and would not apply supplementary bone graft at the time of final debridement and closure.

CONCLUSIONS

There is lack of consensus regarding the appropriate management of thoracolumbar fractures. In the future, multicenter prospective studies are necessary to establish guidelines for the management of thoracolumbar fractures.

Closure of Complex Posterior Midline Defects After Spinal Surgery With Sensate Midline-based Perforator Flaps and the Long-term Results

STUDY DESIGN

Prospective study.

OBJECTIVE

Evaluating the use of a midline-based perforator flap for closure of complex midline defects after spine surgery complicated with implant exposure and deep subfascial infection.

SUMMARY OF BACKGROUND DATA

Traditionally, muscle flaps are used to close complex defects after spine surgery complicated by exposed spinal implants and deep subfascial infections. There are no reports on the long-term results on the use of perforator flaps to close these defects.

METHODS

Information was prospectively registered of all patients in whom a medial dorsal intercostal artery perforator (MDICAP) flap was used for closure of a complex midline defect with exposed spinal implant and deep subfascial infection after spine surgery.

RESULTS

In 9 patients, 10 MDICAP flaps were used. All flaps survived with only 1 flap experiencing marginal flap necrosis. The flaps provided stable coverage of all defects and spinal instrumentation could be retained in all patients. The perforator flaps provided in all patients, except in the patient with a meningomyelocele, protective sensibility in the reconstructed areas. The mean postoperative hospital stay after closure of the defects was 10 days (range 4-21). During follow-up (mean 65 mo, range 7-106) only 1 patient developed an infection in the operated area which occurred 81 months postoperatively. None of the patients had any functional loss at the donor site of the flap.

CONCLUSION

The medial dorsal intercostal artery perforator flap seems to be a reliable alternative for treatment of complex midline defects with exposed spinal implants and deep subfascial surgical site infections. Protective sensibility may be obtained in the reconstructed area with this flap. Donor site morbidity is minimal. In case of recurrence, complex reconstructive procedures using muscle flaps are still possible. The use of this perforator flap may contribute to shorter hospital stays and reduction of costs.

LEVEL OF EVIDENCE

4.

Postoperative Spine Infections

Postoperative spinal wound infection is a potentially devastating complication after operative spinal procedures. Despite the utilization of perioperative prophylactic antibiotics in recent years and improvements in surgical technique and postoperative care, wound infection continues to compromise patients’ outcome after spinal surgery. In the modern era of pending health care reform with increasing financial constraints, the financial burden of post-operative spinal infections also deserves consideration. The aim of our work is to give to the reader an updated review of the latest achievements in prevention, risk factors, diagnosis, microbiology and treatment of postoperative spinal wound infections. A review of the scientific literature was carried out using electronic medical databases Pubmed, Google Scholar, Web of Science and Scopus for the years 1973-2012 to obtain access to all publications involving the incidence, risk factors, prevention, diagnosis, treatment of postoperative spinal wound infections. We initially identified 119 studies; of these 60 were selected. Despite all the measures intended to reduce the incidence of surgical site infections in spine surgery, these remain a common and potentially dangerous complication.

What is new in the diagnosis and prevention of spine surgical site infections

BACKGROUND CONTEXT

Surgical site infection (SSI) after spinal surgery can result in several serious secondary complications, such as pseudoarthrosis, neurological injury, paralysis, sepsis, and death. There is an increasing body of literature on risk factors, diagnosis, and specific intraoperative interventions, including attention to sterility of instrumentation, application of minimally invasive fusion techniques, intraoperative irrigation, and application of topical antibiotics, that hold the most promise for reduction of SSI.

PURPOSE

The purpose of this review is to identify and summarize the recent literature on the incidence, risk factors, diagnosis, prevention, and treatment of SSIs after adult spine surgery.

STUDY DESIGN

The study design included systematic review and literature synthesis.

METHODS

For the systematic reviews, a search was performed in Medline and Scopus using keywords derived from a preliminary review of the literature and Medline MeSH terms. These studies were then manually filtered to meet the study criteria outlined in each section. Studies were excluded via predetermined criteria, and the majority of articles reviewed were excluded.

RESULTS

There are a number of patient- and procedure-specific risk factors for SSI. Surgical site infection appears to have significant implications from the patients' perspective on outcome of care. Diagnosis of SSI appears to rely primarily on clinical factors, while laboratory values such as C-reactive protein are not universally sensitive. Similarly, novel methods of perioperative infection prophylaxis such as local antibiotic administration appear to be modestly effective.

CONCLUSIONS

Surgical site infections are a common multifactorial problem after spine surgery. There is compelling evidence that improved risk stratification, detection, and prevention will reduce SSIs.

Predicting surgical site infection after spine surgery: a validated model using a prospective surgical registry

BACKGROUND CONTEXT

The impact of surgical site infection (SSI) is substantial. Although previous study has determined relative risk and odds ratio (OR) values to quantify risk factors, these values may be difficult to translate to the patient during counseling of surgical options. Ideally, a model that predicts absolute risk of SSI, rather than relative risk or OR values, would greatly enhance the discussion of safety of spine surgery. To date, there is no risk stratification model that specifically predicts the risk of medical complication.

PURPOSE

The purpose of this study was to create and validate a predictive model for the risk of SSI after spine surgery.

STUDY DESIGN

This study performs a multivariate analysis of SSI after spine surgery using a large prospective surgical registry. Using the results of this analysis, this study will then create and validate a predictive model for SSI after spine surgery.

PATIENT SAMPLE

The patient sample is from a high-quality surgical registry from our two institutions with prospectively collected, detailed demographic, comorbidity, and complication data.

OUTCOME MEASURES

An SSI that required return to the operating room for surgical debridement.

MATERIALS AND METHODS

Using a prospectively collected surgical registry of more than 1,532 patients with extensive demographic, comorbidity, surgical, and complication details recorded for 2 years after the surgery, we identified several risk factors for SSI after multivariate analysis. Using the beta coefficients from those regression analyses, we created a model to predict the occurrence of SSI after spine surgery. We split our data into two subsets for internal and cross-validation of our model. We created a predictive model based on our beta coefficients from our multivariate analysis.

RESULTS

The final predictive model for SSI had a receiver-operator curve characteristic of 0.72, considered to be a fair measure. The final model has been uploaded for use on SpineSage.com.

CONCLUSIONS

We present a validated model for predicting SSI after spine surgery. The value in this model is that it gives the user an absolute percent likelihood of SSI after spine surgery based on the patient's comorbidity profile and invasiveness of surgery. Patients are far more likely to understand an absolute percentage, rather than relative risk and confidence interval values. A model such as this is of paramount importance in counseling patients and enhancing the safety of spine surgery. In addition, a tool such as this can be of great use particularly as health care trends toward pay for performance, quality metrics (such as SSI), and risk adjustment. To facilitate the use of this model, we have created a Web site (SpineSage.com) where users can enter patient data to determine likelihood for SSI.

Surgical site infection in spinal surgery: a comparative study between 2-octyl-cyanoacrylate and staples for wound closure

BACKGROUND

Surgical site infection (SSI) after spinal surgery is a devastating complication. Various methods of skin closure are used in spinal surgery, but the optimal skin-closure method remains unclear. A recent report recommended against the use of metal staples for skin closure in orthopedic surgery. 2-Octyl-cyanoacrylate (Dermabond; Ethicon, NJ, USA) has been widely applied for wound closure in various surgeries. In this cohort study, we assessed the rate of SSI in spinal surgery using metal staples and 2-octyl-cyanoacrylate for wound closure.

METHODS

This study enrolled 609 consecutive patients undergoing spinal surgery in our hospital. From April 2007 to March 2010 surgical wounds were closed with metal staples (group 1, n = 294). From April 2010 to February 2012 skin closure was performed using 2-octyl-cyanoacrylate (group 2, n = 315). We assessed the rate of SSI using these two different methods of wound closure. Prospective study of the time and cost evaluation of wound closure was performed between two groups.

RESULTS

Patients in the 2-octyl-cyanoacrylate group had more risk factors for SSI than those in the metal-staple group. Nonetheless, eight patients in the metal-staple group compared with none in the 2-octyl-cyanoacrylate group acquired SSIs (p < 0.01). The closure of the wound in length of 10 cm with 2-octyl-cyanoacrylate could save 28 s and $13.5.

CONCLUSIONS

This study reveals that in spinal surgery, wound closure using 2-octyl-cyanoacrylate was associated with a lower rate of SSI than wound closure with staples. Moreover, the use of 2-octyl-cyanoacrylate has a more time saving effect and cost-effectiveness than the use of staples in wound closure of 10 cm in length.

Management of postoperative spinal infections

Postoperative surgical site infection (SSI) is a common complication after posterior lumbar spine surgery. This review details an approach to the prevention, diagnosis and treatment of SSIs. Factors contributing to the development of a SSI can be split into three categories: (1) microbiological factors; (2) factors related to the patient and their spinal pathology; and (3) factors relating to the surgical procedure. SSI is most commonly caused by Staphylococcus aureus. The virulence of the organism causing the SSI can affect its presentation. SSI can be prevented by careful adherence to aseptic technique, prophylactic antibiotics, avoiding myonecrosis by frequently releasing retractors and preoperatively optimizing modifiable patient factors. Increasing pain is commonly the only symptom of a SSI and can lead to a delay in diagnosis. C-reactive protein and magnetic resonance imaging can help establish the diagnosis. Treatment requires acquiring intra-operative cultures to guide future antibiotic therapy and surgical debridement of all necrotic tissue. A SSI can usually be adequately treated without removing spinal instrumentation. A multidisciplinary approach to SSIs is important. It is useful to involve an infectious disease specialist and use minimum serial bactericidal titers to enhance the effectiveness of antibiotic therapy. A plastic surgeon should also be involved in those cases of severe infection that require repeat debridement and delayed closure.

Polyanalgesic Consensus Conference--2012: recommendations to reduce morbidity and mortality in intrathecal drug delivery in the treatment of chronic pain

INTRODUCTION

Targeted intrathecal drug infusion to treat moderate to severe chronic pain has become a standard part of treatment algorithms when more conservative options fail. This therapy is well established in the literature, has shown efficacy, and is an important tool for the treatment of both cancer and noncancer pain; however, it has become clear in recent years that intrathecal drug delivery is associated with risks for serious morbidity and mortality.

METHODS

The Polyanalgesic Consensus Conference is a meeting of experienced implanting physicians who strive to improve care in those receiving implantable devices. Employing data generated through an extensive literature search combined with clinical experience, this work group formulated recommendations regarding awareness, education, and mitigation of the morbidity and mortality associated with intrathecal therapy to establish best practices for targeted intrathecal drug delivery systems.

RESULTS

Best practices for improved patient care and outcomes with targeted intrathecal infusion are recommended to minimize the risk of morbidity and mortality. Areas of focus include respiratory depression, infection, granuloma, device-related complications, endocrinopathies, and human error. Specific guidance is given with each of these issues and the general use of the therapy.

CONCLUSIONS

Targeted intrathecal drug delivery systems are associated with risks for morbidity and mortality that can be devastating. The panel has given guidance to treating physicians and healthcare providers to reduce the incidence of these problems and to improve outcomes when problems occur.