Surgical Site Infection as a Risk Factor for Long-Term Instrumentation Failure in Patients with Spinal Deformity: A Retrospective Cohort Study

Is Aggressive Surgery Always Necessary for Suspected Early-Onset Surgical Site Infection after Lumbar Surgery? A 10-Year Retrospective Analysis

OBJECTIVE

Surgical site infection (SSI) after spinal surgery is still a persistent worldwide health concern as it is a worrying and devastating complication. The number of samples in previous studies is limited and the role of conservative antibiotic therapy has not been established. This study aims to evaluate the clinical efficacy and feasibility of empirical antibiotic treatment for suspected early-onset deep spinal SSI.

METHODS

We conducted a retrospective study to identify all cases with suspected early-onset deep SSI after lumbar instrumented surgery between January 2009 and December 2018. We evaluated the potential risks for antibiotic treatment, examined the antibiotic treatment failure rate, and applied logistic regression analysis to assess the risk factors for empirical antibiotic treatment failure.

RESULTS

Over the past 10 years, 45 patients matched the inclusion criteria. The success rate of antibiotic treatment was 62.2% (28/45). Of the 17 patients who failed antibiotic treatment, 16 were cured after a debridement intervention and the remaining one required removal of the internal fixation before recovery. On univariate analysis, risk factors for antibiotic treatment failure included age, increasing or persisting back pain, wound dehiscence, localized swelling, and time to SSI (cut-off: 10 days). Multivariate analysis revealed that infection occurring 10 days after primary surgery and wound dehiscence were independent risk factors for antibiotic treatment failure.

CONCLUSION

Appropriate antibiotic treatment is an alternative strategy for suspected early-onset deep SSI after lumbar instrumented surgery. Antibiotic treatment for suspected SSI occurring within 10 days after primary surgery may improve the success rate of antibiotic intervention. Patients with wound dehiscence have a significantly higher likelihood of requiring surgical intervention.

A Sodium Oxychlorosene-Based Infection Prevention Protocol Safely Decreases Postoperative Wound Infections in Adult Spinal Deformity Surgery

INTRODUCTION

This study sought to determine the efficacy of a complex multi-institutional sodium oxychlorosene-based infection protocol for decreasing the rate of surgical site infection after instrumented spinal surgery for adult spinal deformity (ASD). Infection prevention protocols have not been previously studied in ASD patients.

METHODS

A retrospective analysis was performed of patients who underwent posterior instrumented spinal fusion of the thoracic or lumbar spine for deformity correction between January 1, 2011, and May 31, 2019. The efficacy of a multi-modal infection prevention protocol was examined. The infection prevention bundle consisted of methicillin-resistant Staphylococcus aureus testing, chlorhexidine gluconate bathing preoperatively, sodium oxychlorosene rinse, vancomycin powder placement, and surgical drain placement at the time of surgery.

RESULTS

About 254 patients fit the inclusion criteria. Among these patients, nine (3.5%) experienced post-surgical deep-wound infection. Demographics and surgical characteristics amongst infected and non-infected cohorts were similar, although diabetes trended towards being more prevalent in patients who developed a postoperative wound infection (p=0.07). Among 222 patients (87.4%) who achieved a minimum of two years of follow-ups, 184 patients (82.9%) experienced successful fusion, comparing favorably with pseudarthrosis rates in the ASD literature. Rates of pseudarthrosis and proximal junction kyphosis were similar amongst infected and non-infected patients.

CONCLUSION

An intraoperative comprehensive sodium oxychlorosene-based infection prevention protocol helped to provide a low rate of infection after major deformity correction without negatively impacting other postoperative procedure-related metrics.

Delayed Pyogenic Spondylitis at the Same Level as Rod Fracture After Surgery for Adult Spinal Deformity: A Case Report

CASE

Rod fracture (RF) occurred at L5-S level in a 79-year-old woman 7 months after spinal corrective surgery for adult spinal deformity (ASD). Four years after the surgery, pyogenic spondylitis occurred at the same level as RF. After the reinforcement of broken rods posteriorly, a transperitoneal approach was used for debridement and bone graft. However, prolonged infection, adhesive ileus, and small bowel perforation led to a total of 3 reoperations, resulting a colostomy. Three years after the reoperation, she was ambulatory with assistance.

CONCLUSION

We need to follow-up postoperative ASD patients carefully because a single complication can lead to serious consequences.

Risk factors of early complications after thoracic and lumbar spinal deformity surgery: a systematic review and meta-analysis

PURPOSE

To determine risk factors increasing susceptibility to early complications (intraoperative and postoperative within 6 weeks) associated with surgery to correct thoracic and lumbar spinal deformity.

METHODS

We systematically searched the PubMed and EMBASE databases for studies published between January 1990 and September 2021. Observational studies evaluating predictors of early complications of thoracic and lumbar spinal deformity surgery were included. Pooled odds ratio (OR) or standardized mean difference (SMD) with 95% confidence intervals (CI) was calculated via the random effects model.

RESULTS

Fifty-two studies representing 102,432 patients met the inclusion criteria. Statistically significant patient-related risk factors for early complications included neurological comorbidity (OR = 3.45, 95% CI 1.83-6.50), non-ambulatory status (OR = 3.37, 95% CI 1.96-5.77), kidney disease (OR = 2.80, 95% CI 1.80-4.36), American Society of Anesthesiologists score > 2 (OR = 2.23, 95% CI 1.76-2.84), previous spine surgery (OR = 1.98, 95% CI 1.41-2.77), pulmonary comorbidity (OR = 1.94, 95% CI 1.21-3.09), osteoporosis (OR = 1.60, 95% CI 1.17-2.20), cardiovascular diseases (OR = 1.46, 95% CI 1.20-1.78), hypertension (OR = 1.37, 95% CI 1.23-1.52), diabetes mellitus (OR = 1.84, 95% CI 1.30-2.60), preoperative Cobb angle (SMD = 0.43, 95% CI 0.29, 0.57), number of comorbidities (SMD = 0.41, 95% CI 0.12, 0.70), and preoperative lumbar lordotic angle (SMD = - 0.20, 95% CI - 0.35, - 0.06). Statistically significant procedure-related factors were fusion extending to the sacrum or pelvis (OR = 2.53, 95% CI 1.53-4.16), use of osteotomy (OR = 1.60, 95% CI 1.12-2.29), longer operation duration (SMD = 0.72, 95% CI 0.05, 1.40), estimated blood loss (SMD = 0.46, 95% CI 0.07, 0.85), and number of levels fused (SMD = 0.37, 95% CI 0.03, 0.70).

CONCLUSION

These data may contribute to development of a systematic approach aimed at improving quality-of-life and reducing complications in high-risk patients.

Surgical site infection is a major risk factor of pseudarthrosis in adult spinal deformity surgery

BACKGROUND CONTEXT

Despite the evidence in appendicular skeletal surgery, the effect of infection on spinal fusion remains unclear, particularly after Adult Spinal Deformity (ASD) surgery.

PURPOSE

The purpose of this study was to determine the impact of surgical site infection (SSI) in ASD surgery fusion rates and its association with other risks factors of pseudarthrosis.

STUDY DESIGN

We conducted an international multicenter retrospective study on a prospective cohort of patients operated for spinal deformity.

PATIENT SAMPLE

A total of 956 patients were included (762 females and 194 males).

OUTCOME MEASURES

Patient's preoperative characteristics, pre and postoperative spinopelvic parameters, surgical variables, postoperative complications and were recorded. Surgical site infections were asserted in case of clinical signs associated with positive surgical samples. Each case was treated with surgical reintervention for debridement and irrigation. Presence of pseudarthrosis was defined by the association of clinical symptoms and radiological signs of nonfusion (either direct evidence on CT-scan or indirect radiographic clues such as screw loosening, rod breakage, screw pull out or loss of correction). Each iterative surgical intervention was collected.

METHODS

Univariate and multivariate analysis with logistic regression models were performed to evaluate the role of risk factors of pseudarthrosis.

RESULTS

Nine hundred fifty-six surgical ASD patients with more than two years of follow-up were included in the study. 65 of these patients were treated for SSI (6.8%), 138 for pseudarthrosis (14.4%), and 28 patients for both SSI and pseudarthrosis. On multivariate analysis, SSI was found to be a major risk factor of pseudarthrosis (OR=4.4; 95% CI=2.4,7.9) as well as other known risks factors: BMI (OR=1.1; 95% CI=1.0,1.1), smoking (OR=1.6; 95% CI=1.1,2.9), performance of Smith-Petersen osteotomy (OR = 1.6; 95% CI 1.0,2.6), number of vertebrae instrumented (OR=1.1; 95% CI=1.1,1.2) and the caudal level of fusion, with a distal exponential increment of the risk (OR max for S1=6, 95% CI=1.9,18.6).

CONCLUSION

SSI significantly increases the risk of pseudarthrosis with an OR of 4.4.

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

STUDY DESIGN

A meta-analysis.

BACKGROUND

We performed a meta-analysis to explore risk factors of surgical site infection (SSI) following spinal surgery.

METHODS

An extensive search of literature was performed in English database of PubMed, Embase, and Cochrane Library and Chinese database of CNKI and WANFANG (up to October 2020). We collected factors including demographic data and surgical factor. Data analysis was conducted with RevMan 5.3 and STATA 12.0.

RESULTS

Totally, 26 studies were included in the final analysis. In our study, the rate of SSI after spinal surgery was 2.9% (1222 of 41,624). Our data also showed that fusion approach (anterior vs posterior; anterior vs combined), osteotomy, transfusion, a history of diabetes and surgery, hypertension, surgical location (cervical vs thoracic; lumbar vs thoracic), osteoporosis and the number of fusion levels were associated with SSI after spinal surgery. However, age, sex, a history of smoking, body mass index, fusion approach (posterior vs combined), surgical location (cervical vs lumbar), duration of surgery, blood loss, using steroid, dural tear and albumin were not associated with development of SSI.

CONCLUSIONS

In our study, many factors were associated with increased risk of SSI after spinal surgery. We hope this article can provide a reference for spinal surgeons to prevent SSI after spinal surgery.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines for Perioperative Spine: Preoperative Surgical Risk Assessment

BACKGROUND

Patient factors (increased body mass index [BMI], smoking, and diabetes) may impact outcomes after spine surgery. There is a lack of consensus regarding which factors should be screened for and potentially modified preoperatively to optimize outcome.

OBJECTIVE

The purpose of this evidence-based clinical practice guideline is to determine if preoperative patient factors of diabetes, smoking, and increased BMI impact surgical outcomes.

METHODS

A systematic review of the literature for studies relevant to spine surgery was performed using the National Library of Medicine PubMed database and the Cochrane Library. Clinical studies evaluating the impact of diabetes or increased BMI with reoperation and/or surgical site infection (SSI) were selected for review. In addition, the impact of preoperative smoking on patients undergoing spinal fusion was reviewed.

RESULTS

A total of 699 articles met inclusion criteria and 64 were included in the systematic review. In patients with diabetes, a preoperative hemoglobin A1c (HbA1c) >7.5 mg/dL is associated with an increased risk of reoperation or infection after spine surgery. The review noted conflicting studies regarding the relationship between increased BMI and SSI or reoperation. Preoperative smoking is associated with increased risk of reoperation (Grade B). There is insufficient evidence that cessation of smoking before spine surgery decreases the risk of reoperation.

CONCLUSION

This evidence-based guideline provides a Grade B recommendation that diabetic individuals undergoing spine surgery should have a preoperative HbA1c test before surgery and should be counseled regarding the increased risk of reoperation or infection if the level is >7.5 mg/dL. There is conflicting evidence that BMI correlates with greater SSI rate or reoperation rate (Grade I). Smoking is associated with increased risk of reoperation (Grade B) in patients undergoing spinal fusion.The full guidelines can be accessed at https://www.cns.org/guidelines/browse-guidelines-detail/2-preoperative-surgical-risk-assessement.

Surgical revision strategies for postoperative spinal implant infections (PSII)

Over the last years the number of spine surgeries with instrumentation has grown to an indispensable column in the treatment for different pathologies of the spine. A further increase in the incidence of instrumented spinal surgery is expected throughout the next years. Although the implementation and development of new techniques offer faster and more minimal invasive procedures, shortening surgery time, reducing soft tissue injury and revision due to hardware misplacement, the incidence of postoperative spinal implant infections (PSII) remains high. PSII related complications and revision procedures pose an enormous socioeconomic burden. Therefore, standardized strategies and protocols for treatment of PSII are urgently needed. While in former times hardware exchange or hardware removal was common practise in the field of spine surgery this approach has changed over the last years. Although the evidence from clinical studies in the field of PSII is of limited evidence, critical variables for revision strategies of PSII have been identified. Further, to quickly advance in the field of PSII it is certainly important to extrapolate and learn using data regarding the management from other fields of prosthetic joint infections. This should include clinical as well as experimental work in particular in the context of the biofilm, sonication as well as microbiological concepts. Over the last years, at our institution standardized procedures for diagnostic, surgical as well as antimicrobial treatment have been developed, based on the latest recommendations in peer-reviewed literature and our own data. Here we give an overview about surgical revision strategies for PSII and discuss the key points of our standardized protocol.

Risk factors for neurological complications in severe and rigid spinal deformity correction of 177 cases

BACKGROUND

Difficult procedures of severe rigid spinal deformity increase the risk of intraoperative neurological injury. Here, we aimed to investigate the preoperative and intraoperative risk factors for postoperative neurological complications when treating severe rigid spinal deformity.

METHODS

One hundred seventy-seven consecutive patients who underwent severe rigid spinal deformity correction were assigned into 2 groups: the neurological complication (NC, 22 cases) group or non-NC group (155 cases). The baseline demographics, preoperative spinal cord functional classification, radiographic parameters (curve type, curve magnitude, and coronal/sagittal/total deformity angular ratio [C/S/T-DAR]), and surgical variables (correction rate, osteotomy type, location, shortening distance of the osteotomy gap, and anterior column support) were analyzed to determine the risk factors for postoperative neurological complications.

RESULTS

Fifty-eight patients (32.8%) had intraoperative evoked potentials (EP) events. Twenty-two cases (12.4%) developed postoperative neurological complications. Age and etiology were closely related to postoperative neurological complications. The spinal cord functional classification analysis showed a lower proportion of type A, and a higher proportion of type C in the NC group. The NC group had a larger preoperative scoliosis angle, kyphosis angle, S-DAR, T-DAR, and kyphosis correction rate than the non-NC group. The results showed that the NC group tended to undergo high-grade osteotomy. No significant differences were observed in shortening distance or anterior column support of the osteotomy area between the two groups.

CONCLUSIONS

Postoperative neurological complications were closely related to preoperative age, etiology, severity of deformity, angulation rate, spinal cord function classification, intraoperative osteotomy site, osteotomy type, and kyphosis correction rate. Identification of these risk factors and relative development of surgical techniques will help to minimize neural injuries and manage postoperative neurological complications.