Prospective multicenter surveillance and risk factor analysis of deep surgical site infection after posterior thoracic and/or lumbar spinal surgery in adults

Predictive value of the preoperative C-reactive protein-to-albumin ratio for surgical site infection after percutaneous kyphoplasty: a single-center retrospective study

Objective

This study aimed to investigate the risk factors for surgical site infection (SSI) after percutaneous kyphoplasty (PKP) and evaluate the application value of the preoperative C-reactive protein (CRP)-to-albumin ratio (CAR) in predicting SSI.

Methods

This study retrospectively enrolled 329 patients with thoracolumbar compression fractures who underwent PKP in the Affiliated Hospital of Qingdao University from January 2019 to June 2024. The demographic information, surgery-related data and laboratory examination results of the patients were collected. According to these results, the patients were divided into SSI and non-SSI groups, and the results were compared and analyzed. The receiver operating characteristic curve was used to determine the optimal cutoff value of preoperative CAR for predicting SSI, and binary logistic regression analysis was employed to evaluate the predictive value of CAR for SSI. The risk factors of SSI in the thoracolumbar subgroup were further explored.

Results

The study enrolled a total of 329 patients, and SSI occurred in 29 (8.81%). The optimal cut-off value of CAR was 0.1213, and the area under the curve was 0.808 (P < 0. 001). The results showed that SSI rates were related to the surgical site, and the SSI rate in the lumbar spine was higher than that in the thoracic spine. The SSI group had a longer surgical duration and more operated segments. The levels of preoperative CRP, CAR, procalcitonin and erythrocyte sedimentation rate (ESR) were higher; however, serum albumin levels were lower. More patients had CAR ≥0.1213 (75.86% vs 25.33%) and white blood cell (WBC) >10*109 (27.59% vs 10.00%). In addition, no significant differences were found by the other demographic data and laboratory examinations between the two groups. In the binary logistic regression analysis, preoperative CAR was an independent risk factor for post-PKP SSI, and the SSI risk increased by 7.464 times in patients with CAR ≥0.1213. The number of operated segments, surgical duration, and ESR were also independent risk factors for SSI, whereas serum albumin is a protective factor.

Conclusion

Preoperative CAR is an effective predictor of post-PKP SSI, which can be used for clinical prevention and reduction of SSI risk.

Development and validation of a clinical nomogram prediction model for surgical site infection following lumbar disc herniation surgery

Surgical site infection (SSI) following lumbar disc herniation (LDH) surgery leads to prolonged hospital stays, increased costs and reoperations. Therefore, we aim to develop and validate a nomogram to predict the risk of SSI following LDH surgery, thereby helping spine surgeons design personalized prevention strategies and promote early recovery. Data from 647 patients with SSI who underwent LDH surgery at the First Affiliated Hospital of Air Force Medical University (AFMU) from 2020 to 2023 were collected. Ultimately, 241 patients with SSI were selected based on inclusion and exclusion criteria. Patients were randomly divided into training and validation sets with a ratio of 7:3. LASSO regression, univariate, and multivariate logistic regression were utilized to identify target variables and establish the prediction model, which was subsequently validated. Six factors-Age, Body Mass Index (BMI), Postoperative Suction Drainage (PSD), Gelatin Sponge (GS), None-Preoperative Antibiotic (NPTA), and Thrombin Time (TT)-were selected to construct the nomogram model. In the training set, the area under the curve (AUC) for the nomogram was 0.818 (95% CI 0.779-0.857). In the validation set, the AUC was 0.782 (95% CI 0.717-0.846). Calibration curves for both sets showed satisfactory agreement between predicted and actual SSI probabilities. Decision curve analysis indicated that the nomogram is clinically useful with a threshold range of 1-90%. The Clinical Impact Curve (CIC) demonstrated an acceptable cost-benefit ratio. The developed nomogram model effectively predicts the risk of SSI following LDH surgery, enabling spine surgeons to formulate more professional and rational clinical prevention strategies.

Effect of pre-operative HbA1c and blood glucose level on the surgical site infection after lumbar instrumentation surgery

BACKGROUND

This study aims to investigate the effect of pre-operative hemoglobin A1c (HbA1c) and pre-operative blood glucose control on the rate of surgical site infection (SSI) after posterior lumbar instrumentation surgery in diabetes mellitus (DM) patients.

METHODS

A total of 1046 patients who had undergone posterior lumbar instrumentation surgery were reviewed. Based on pre-operative HbA1c, patients were divided into three groups: non-DM group, low HbA1c group (HbA1c < 7.0 % in DM) and high HbA1c group (≥7.0). As well, based on the status of blood glucose control in DM patients immediately before surgery, patients were divided into two groups: good control group (post-prandial blood glucose [PBG] < 200 mg/dl) and poor control group (≥200). The rate of SSI was compared among these groups.

RESULTS

SSI occurred in 1.9 % in non-DM group, 2.4 % in low HbA1c group, and 9.3 % in high HbA1c group. Compared with non-DM group, high HbA1c group had significantly higher rate of SSI (p = 0.001). There was not statistically different between non-DM and low HbA1c groups (p = 0.550). SSI occurred in 2.2 % in good control group, and 10.2 % in poor control group. The rate of SSI was significantly lower in good control group (p = 0.013).

CONCLUSION

This study showed that the rate of SSI after posterior lumbar instrumentation surgery tend to be higher in DM patients with high HbA1c. However, the rate might be reduced to the same level as that of non-DM group by lowering PBG to <200 mg/dl immediately before surgery.

Unilateral versus bilateral pedicle screw fixation with anterior lumbar interbody fusion: a comparison of postoperative outcomes

PURPOSE

To determine of the impact of ALIF with minimally invasive unilateral pedicle screw fixation (UPSF) versus bilateral pedicle screw fixation (BPSF) on perioperative outcomes, radiographic outcomes, and the rates of fusion, subsidence, and adjacent segment stenosis.

METHODS

All adult patients who underwent one-level ALIF with UPSF or BPSF at an academic institution between 2015 and 2022 were retrospectively identified. Postoperative outcomes including length of hospital stay (LOS), wound complications, readmissions, and revisions were determined. The rates of fusion, screw loosening, adjacent segment stenosis, and subsidence were assessed on one-year postoperative CT. Lumbar alignment including lumbar lordosis, L4-S1 lordosis, regional lordosis, pelvic tilt, pelvic incidence, and sacral slope were assessed on standing x-rays at preoperative, immediate postoperative, and final postoperative follow-up. Univariate and multivariate analysis compared outcomes across posterior fixation groups.

RESULTS

A total of 60 patients were included (27 UPSF, 33 BPSF). Patients with UPSF were significantly younger (p = 0.011). Operative time was significantly greater in the BPSF group in univariate (p < 0.001) and multivariate analysis (ß=104.1, p < 0.001). Intraoperative blood loss, LOS, lordosis, pelvic parameters, fusion rate, subsidence, screw loosening, adjacent segment stenosis, and revision rate did not differ significantly between fixation groups. Though sacral slope (p = 0.037) was significantly greater in the BPSF group, fixation type was not a significant predictor on regression.

CONCLUSIONS

ALIF with UPSF relative to BPSF predicted decreased operative time but was not a significant predictor of postoperative outcomes. ALIF with UPSF can be considered to increase operative efficiency without compromising construct stability.

Role of Pre-Operative Nutrition Status on Surgical Site Infection After Posterior Lumbar Interbody Fusion: A Retrospective Study

Background: A retrospective case-control study to determine the role of pre-operative systemic and local nutritional factors on patients developing a surgical site infection (SSI) after posterior lumbar interbody fusion (PLIF). Surgical site infection after PLIF remains a substantial cause of morbidity. The literature demonstrates the prognosis of surgical patients is associated with pre-operative nutritional status that not only includes systemic nutritional factors, such as prognostic nutritional index (PNI), body mass index (BMI), and serum albumin, but also local nutritional factors, such as subcutaneous fat thickness at the surgical site, including absolute fat thickness and relative fat thickness. However, the role of pre-operative nutrition status in SSI after PLIF surgery remains unclear. Patients and Method: A retrospective review was performed on a consecutive cohort of 766 consecutive adult patients who underwent PLIF surgery for lumbar degenerative conditions between 2020 and 2021 at Second Xiangya Hospital. Previously identified risk factors as well as systemic and local nutritional factors nutritional factors were collected. Results: Among the 766 patients, 38 had post-operative SSI including 15 superficial SSI and 23 deep SSI. Univariable analysis showed that body weight, BMI, PNI, serum albumin, and relative fat thickness differed between the SSI and non-SSI groups. Multivariable logistic regression analysis showed that pre-operative PNI and relative fat thickness were independently associated with SSI after PLIF surgery. Conclusions: Lower pre-operative PNI and higher relative fat thickness are independent risk factors for developing deep SSI after PLIF.

Does Postoperative Spine Infection Bacterial Gram Type Affect Surgical Debridement or Antibiotic Duration?

STUDY DESIGN

This is a retrospective cohort study.

OBJECTIVE

The aim was to evaluate differences in readmission rates, number of debridements, and length of antibiotic therapy when comparing bacterial gram type following lumbar spinal fusion infections.

SUMMARY OF BACKGROUND DATA

Surgical site infections (SSIs) after spinal fusion serve as a significant source of patient morbidity. It remains to be elucidated how bacterial classification of the infecting organism affects the management of postoperative spinal SSI.

METHODS

Patients who underwent spinal fusion with a subsequent diagnosis of SSI between 2013 and 2019 were retrospectively identified. Patients were grouped based on bacterial infection type (gram-positive, gram-negative, or mixed infections). Poisson regressions analyzed the relationship between the type of bacterial infection and the number of irrigation and debridement (I&D) reoperations, and the duration of intravenous (IV) antibiotic therapy. Significance was set at P <0.05.

RESULTS

Of 190 patients, 92 had gram-positive (G+) infections, 57 had gram-negative (G-) infections, and 33 had mixed (M) infections. There was no difference in 30 or 90-day readmissions for infection between groups (both P =0.051). Patients in the M group had longer durations of IV antibiotic treatment (G+: 46.4 vs. G-: 41.0 vs. M: 55.9 d, P =0.002). Regression analysis demonstrated mixed infections were 46% more likely to require a greater number of debridements ( P =0.001) and 18% more likely to require an increased duration of IV antibiotic therapy ( P <0.001), while gram-negative infections were 10% less likely to require an increased duration of IV antibiotic therapy ( P <0.001) when compared with G- infections.

CONCLUSION

Spinal SSI due to a mixed bacterial gram type results in an increased number of debridements and a longer duration of IV antibiotics required to resolve the infection compared with gram-negative or gram-positive infections.

LEVEL OF EVIDENCE

Level III.

Effect of Fellow Involvement and Experience on Patient Outcomes in Spine Surgery

INTRODUCTION

Investigations in spine surgery have demonstrated that trainee involvement correlates with increased surgical time, readmissions, and revision surgeries; however, the specific effects of spine fellow involvement remain unelucidated. This study aims to investigate the isolated effect of fellow involvement on surgical timing and patient-reported outcomes measures (PROMs) after spine surgery and evaluate how surgical outcomes differ by fellow experience.

METHODS

All patients aged 18 years or older who underwent primary or revision decompression or fusion for degenerative diseases and/or spinal deformity between 2017 and 2019 at a single academic institution were retrospectively identified. Patient demographics, surgical factors, intraoperative timing, transfusion status, length of stay (LOS), readmissions, revision rate, and preoperative and postoperative PROMs were recorded. Surgeries were divided based on spine fellow participation status and occurrence in the start or end of fellowship training. Univariate and multivariate analyses compared outcomes across fellow involvement and fellow experience groups.

RESULTS

A total of 1,108 patients were included. Age, preoperative diagnoses, number of fusion levels, and surgical approach differed markedly by fellow involvement. Fellow training experience groups differed by patient smoking status, preoperative diagnosis, and surgical approach. On univariate analysis, spine fellow involvement was associated with extended total theater time, induction start to cut time, cut to close time, and LOS. Increased spine fellow training was associated with reduced cut to close time and LOS. On regression, fellow involvement predicted cut to close extension while increased fellow training experience predicted reduction in cut to close time, both independent of surgical factors and assisting residents or physician assistants. Transfusions, readmissions, revision rate, and PROMs did not differ markedly by fellow involvement or experience.

CONCLUSION

Spine fellow participation predicted extended procedural duration. However, the presence of a spine fellow did not affect long-term postoperative outcomes. Furthermore, increased fellow training experience predicted decreased procedural time, underscoring a learning effect.

AVAILABILITY OF DATA AND MATERIAL

The data sets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.

LEVEL OF EVIDENCE

Level 3.

The impact of case order and intraoperative staff changes on spine surgical efficiency

BACKGROUND CONTEXT

Despite concerted efforts toward quality improvement in high-volume spine surgery, there remains concern that increases in case load may compromise the efficient and safe delivery of surgical care. There is a paucity of evidence to describe the effects of spine case order and operating room (OR) team structure on measures of intraoperative timing and OR efficiency.

PURPOSE

This study aims to determine if intraoperative staff changes and surgical case order independently predict extensions in intraoperative timing after spinal surgery for spondylotic diseases.

STUDY DESIGN/ SETTING

Retrospective cohort analysis PATIENT SAMPLE: All patients over age 18 who underwent primary or revision decompression and/or fusion for degenerative spinal diseases between 2017 to 2019 at a single academic institution were retrospectively identified. Exclusion criteria included absence of descriptive data and intraoperative timing parameters as well as surgery for traumatic injury, infection, and malignancy.

OUTCOME MEASURES

Intraoperative timing metrics including total theater time, wheels in to induction, induction start to cut, cut to close, and close to wheels out. Postoperative outcomes included length of hospital stay and 90-day hospital readmissions.

METHODS

Surgical case order and intraoperative changes in staff (circulator and surgical scrub nurse or technician) were determined. Patient demographics, surgical factors, intraoperative timing and postoperative outcomes were recorded. Extensions in each operative stage were determined as a ratio of the actual duration of the parameter divided by the predicted duration of the parameter. Univariate and multivariate analyses were performed to compare outcomes within case order and staff change groups.

RESULTS

A total of 1,108 patients met the inclusion criteria. First, second, and third start cases differed significantly in intraoperative extensions of total theater time, wheels in to induction, induction start to cut, cut to close, and close to wheels out. On regression, decreasing case order predicted extension in wheels in to induction time. Surgeries with intraoperative staff changes were associated with increases in total theater time, induction start to cut time, cut to close time, close to wheels out time, and length of hospital stay. Switch in primary circulator predicted extended theater time and cut to close time. Relief of primary circulator or scrub predicted extended total theater time, induction start to cut time, cut to close time, and close to wheels out time.

CONCLUSIONS

Intraoperative staff change in spine surgery independently predicted extended operative duration. However, higher case order was not significantly associated with procedural time.

Is the Use of Intraoperative 3D Navigation for Thoracolumbar Spine Surgery a Risk Factor for Post-Operative Infection?

Pedicle screw fixation is a technique used to provide rigid fixation in thoracolumbar spine surgery. Safe intraosseous placement of pedicle screws is necessary to provide optimal fixation as well as to avoid damage to adjacent anatomic structures. Despite the wide variety of techniques available, none thus far has been able to fully eliminate the risk of malpositioned screws. Intraoperative 3-dimensional navigation (I3DN) was developed to improve accuracy in the placement of pedicle screws. To our knowledge, no previous studies have investigated whether infection rates are higher with I3DN. A single-institution, retrospective study of patients age > 18 undergoing thoracolumbar fusion and instrumentation was carried out and use of I3DN was recorded. The I3DN group had a significantly greater rate of return to the operating room for culture-positive incision and drainage (17 (4.1%) vs. 1 (0.6%), p = 0.025). In multivariate analysis, the use of I3DM did not reach significance with an OR of 6.49 (0.84−50.02, p = 0.073). Post-operative infections are multifactorial and potential infection risks associated with I3DN need to be weighed against the safety benefits of improved accuracy of pedicle screw positioning.

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.

Intraoperative Navigation in Spine Surgery: Effects On Complications and Reoperations

INTRODUCTION

Intraoperative navigation during spine surgery improves pedicle screw placement accuracy. However, limited studies have correlated navigation with clinical factors including operative time and safety. This study compares complications and reoperations between surgeries with and without navigation.

METHODS

Posterior cervical and lumbar fusions and deformity surgeries from 2011-2018 were queried from the NSQIP database and divided by navigation use. Patients aged >89, deformity patients aged <25, and patients undergoing surgery for tumors, fractures, infections, or non-elective indications were excluded. Demographics and perioperative factors were compared with univariate analysis. Outcomes were compared with multivariable logistic regression adjusting for age, sex, BMI, ASA class, surgical region, and multiple levels. Outcomes were also compared stratifying by revision status.

RESULTS

Navigated surgery patients had higher ASA status (p<0.0001), more multiple-level surgeries (p<0.0001), and longer operations (p<0.0001). Adjusted analysis revealed navigated lumbar surgeries had lower odds of complications (OR=0.82, 95%CI=0.77-0.90, p<0.0001), blood transfusion (OR=0.79, 95%CI=0.72-0.87, p<0.0001), and wound debridement/drainage (OR=0.66, 95%CI=0.44-0.97, p=0.04) compared to non-navigated procedures. Navigated cervical fusions had increased odds of transfusion (OR=1.53, 95%CI=1.06-2.23, p=0.02). Navigated primary fusions had decreased odds of complications (OR=0.91, 95%CI=0.85-0.98, p=0.01); no difference was found in revisions (OR=0.89, 95%CI=0.69-1.14, p=0.34).

CONCLUSIONS

Navigated surgery patients experienced longer operations due to a combination of time using navigation, more multi-level procedures and larger comorbidity burden, without differences in infections. There were fewer complications and wound washouts in navigated lumbar surgeries due to a higher percentage of minimally invasive cases. Co-utilization of navigation and minimally invasive surgery may benefit properly indicated patients.

A SCORING SYSTEM TO PREDICT THE RISK OF SURGICAL SITE INFECTIONS AFTER SPINAL SURGERY

ABSTRACT Objective This retrospective clinical study was carried out to generate and cross-validate a scoring system for the identification of patients at risk of SSIs after spinal surgery. Methods A retrospective study was conducted, which included patients who underwent spinal surgery. The potential variables for SSIs were extracted from the database, including preoperative, intraoperative and postoperative risk factors for univariate and multivariate regression analyses. Results A total of 2347 patients were included in this retrospective clinical study. Postoperative SSIs were observed in 53 patients (2.2%). The multivariate logistic regression analysis revealed the following risk factors for SSIs after spinal surgery: diabetes mellitus ( P =0.029), body mass index ( P =0.008), low serum calcium concentration ( P =0.012), low pre- and postoperative albumin ( P =0.023, P =0.037), more than three operated segments ( P =0.008), operation time of more than 180 minutes ( P =0.019), estimated blood loss ( P =0.011), low postoperative hemoglobin ( P =0.017) and prolonged drainage time ( P =0.025). Each of these factors contributed 1 point to the risk score. The predicted rates of incidence for the low-, intermediate-, high-, and extremely high-risk categories in the validation set were 1.4%, 12%, 41.6%, and 66.6%, respectively. Conclusions Our scoring system allows for easy and validated risk stratification of SSIs after spinal surgery. Level of evidence III; Cross-sectional Observational Study.

Risk factors associated with surgical site infections after thoracic or lumbar surgery: a 6-year single centre prospective cohort study

BACKGROUND

Surgical site infection (SSI) is a risk in every operation. Infections negatively impact patient morbidity and mortality and increase financial demands. The aim of this study was to analyse SSI and its risk factors in patients after thoracic or lumbar spine surgery.

METHODS

A six-year single-centre prospective observational cohort study monitored the incidence of SSI in 274 patients who received planned thoracic or lumbar spinal surgery for degenerative disease, trauma, or tumour. They were monitored for up to 30 days postoperatively and again after 1 year. All patients received short antibiotic prophylaxis and stayed in the eight-bed neurointensive care unit (NICU) during the immediate postoperative period. Risk factors for SSI were sought using multivariate logistic regression analysis.

RESULTS

We recorded 22 incidences of SSI (8.03%; superficial 5.84%, deep 1.82%, and organ 0.36%). Comparing patients with and without SSI, there were no differences in age (p=0.374), gender (p=0.545), body mass index (p=0.878), spine diagnosis (p=0.745), number of vertebrae (p=0.786), spine localization (p=0.808), implant use (p=0.428), American Society of Anesthesiologists (ASA) Score (p=0.752), urine catheterization (p=0.423), drainage (p=0.498), corticosteroid use (p=0.409), transfusion (p=0.262), ulcer prophylaxis (p=0.409) and diabetes mellitus (p=0.811). The SSI group had longer NICU stays (p=0.043) and more non-infectious hospital wound complications (p<0.001). SSI risk factors according to our multivariate logistic regression analysis were hospital wound complications (OR 20.40, 95% CI 7.32-56.85, p<0.001) and warm season (OR 2.92, 95% CI 1.03-8.27, p=0.044).

CONCLUSIONS

Contrary to the prevailing literature, our study did not identify corticosteroids, diabetes mellitus, or transfusions as risk factors for the development of SSI. Only wound complications and warm seasons were significantly associated with SSI development according to our multivariate regression analysis.

Risk factors for deep surgical site infection after posterior cervical spine surgery in adults: a multicentre observational cohort study

Surgical site infection (SSI) is a serious complication following spine surgery and is correlated with significant morbidities, poor clinical outcomes, and increased healthcare costs. Accurately identifying risk factors can help develop strategies to reduce this devastating consequence; however, few multicentre studies have investigated risk factors for SSI following posterior cervical spine surgeries. Between July 2010 and June 2015, we performed an observational cohort study on deep SSI in adult patients who underwent posterior cervical spine surgery at 10 research hospitals. Detailed patient- and procedure-specific potential risk variables were prospectively recorded using a standardised data collection chart and were reviewed retrospectively. Among the 2184 consecutive adult patients enrolled, 28 (1.3%) developed postoperative deep SSI. Multivariable regression analysis revealed 2 statistically significant independent risk factors: occipitocervical surgery (P < 0.001) and male sex (P = 0.024). Subgroup analysis demonstrated that occipitocervical surgery (P = 0.001) was the sole independent risk factor for deep SSI in patients with instrumented fusion. Occipitocervical surgery is a relatively rare procedure; therefore, our findings were based on a large cohort acquired using a multicentre study. To the best of our knowledge, this is the first study to identify occipitocervical procedure as an independent risk variable for deep SSI after spinal surgery.

Risk factors for surgical site infections following spinal column trauma in an Australian trauma hospital

BACKGROUND

There is limited, and often conflicting, data in the literature about the prevalence and risk factors for surgical site infections (SSI) in spine surgery patients, with the majority consisting of elective spine surgery cohorts. Furthermore, there is no reported Australian data regarding rates of SSI in a spinal trauma cohort. The aim of this study is to identify factors associated with SSI following spinal column trauma.

METHODS

Adult (16+ years) patients that underwent surgery following emergency admission for spinal 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 confirmed from the electronic medical record. Patient and clinical factors were analysed by SSI status. Generalized Estimating Equations were used to model predictors of SSI, with a P-value <0.05 deemed significant.

RESULTS

Data for 458 patients and 520 surgical wounds were collected. Twenty-six (5.7%) patients developed an SSI. Staphylococcus aureus was the most common microorganism with methicillin-sensitive S. aureus found in 46% of SSI cases. A posterior surgical approach and same site reoperation were predictors of SSI with adjusted odds ratios (95% confidence intervals) of 4.26 (1.22-14.80, P = 0.02) and 4.99 (1.10-22.58, P = 0.04), respectively.

CONCLUSIONS

A posterior surgical approach and same site reoperation increased the risk of SSI after spinal trauma. Further research into modifiable associations within these and other factors will help mitigate the risk of SSI and hence decrease the personal and financial costs of this potentially devastating complication.

Prevalence of Occult Infections in Posterior Instrumented Spinal Fusion

STUDY DESIGN

This is a prospective observational study.

OBJECTIVE

The aim of this study is to determine the rate of occult infection after instrumented spine surgery in presumed aseptic patients.

SUMMARY OF BACKGROUND DATA

The reported incidence rate of delayed/occult infection determined by positive culture swabs after instrumented spine surgery in prospective studies is 0.2%-6.9%. However, this rate may be higher as delayed infections are challenging to diagnose. Fever can be absent and inflammatory markers are often normal. If indolent organisms exist in low concentrations surrounding the instrumentation, these organisms can possibly avoid detection and disrupt bone formation leading to instrumentation loosening, pain generation, and/or failure of a solid fusion.

MATERIALS AND METHODS

This study included 50 consecutive presumed aseptic patients undergoing a posterior revision requiring removal of instrumentation at least 6 months following their index procedure. Common markers of infection were examined preoperatively. Multiple culture swabs were taken directly from the removed instrumentation and cultured for 14 days.

RESULTS

Of the 50 patients, 19 (38%) were culture-positive (CP) for bacteria upon removal of their instrumentation, with 14 patients (28%) having ≥2 positive specimens of the same organism. The average length of time between the index procedure and the revision surgery was 4.55 years (range: 0.53-21 y). Polymicrobial infections were found in 26% (5/19) of CP patients. The most prevalent microorganism found was Propionibacterium acnes, in 63% (12/19) of CP patients. There was no significant difference between CP and culture-negative patients regarding preoperative markers for infection, age, or length between index and revision procedures.

CONCLUSIONS

The results of this study indicate a positive culture rate of 38% in presumed aseptic patients who had previously undergone instrumented spine surgery. These results are consistent with other retrospective studies and are >6 times greater than any previous prospective study utilizing culture swabs.

LEVEL OF EVIDENCE

Level-III.

Type of bone graft and primary diagnosis were associated with nosocomial surgical site infection after high tibial osteotomy: analysis of a national database

PURPOSE

Although several small-scale studies have reported risk factors for surgical site infection (SSI) after high tibial osteotomy (HTO), no study has collectively analysed risk factors in a large cohort. The present study aimed to clarify the risk factors for SSI after HTO using a national database.

METHODS

Data of inpatients who underwent HTO from 2010 to 2017 were obtained from the Diagnosis Procedure Combination database in Japan. Outcome measures were the incidence of SSI and deep SSI after HTO. Associations between SSI and patient data were examined with multivariable logistic regression analysis.

RESULTS

Among 12,853 patients who underwent HTO, 195 developed SSI (1.52%) and 50 developed deep SSI (0.39%). Univariate analysis showed that male sex, smoking, and longer anaesthesia duration were associated with higher incidences of SSI, whereas a primary diagnosis of osteonecrosis and use of natural bone grafts were associated with lower incidences. In multivariable analysis, SSI was positively associated with male sex, anaesthesia duration longer than 210 min (vs. 150-210 min), and use of artificial bone graft (vs. natural bone graft). SSI was negatively associated with age ≤ 49 years (vs. 50-59 years) and a primary diagnosis of osteonecrosis (vs. osteoarthritis).

CONCLUSION

The present study revealed novel risk factors for SSI after HTO that previous studies have failed to find, including use of artificial bone graft and longer anaesthesia duration; primary diagnosis of osteonecrosis and younger age were novel protective factors. These findings will help surgeons assess risks of SSI after HTO in individual patients.

LEVEL OF EVIDENCE

III.

Does preoperative prognostic nutrition index predict surgical site infection after spine surgery?

PURPOSE

Malnutrition is reported as one of the risk factors for surgical site infection (SSI). The prognostic nutritional index (PNI) is a simple method for nutritional evaluation. However, little is known about the relationship between SSI and the PNI in patients after spine surgery. We aimed to determine independent predictors of SSI after spine surgery.

METHODS

We analyzed 1115 patients who underwent spine surgery (369 males, 746 females, mean age 56 years, follow-up period: at least 1 year). Patients were divided into SSI and non-SSI groups. Preoperative risk factors, including PNI (10 × serum albumin [g/dL] + 0.005 × total lymphocyte count [/μL]), were assessed.

RESULTS

Postoperatively, 43 patients (3.9%) experienced SSI. Univariate analysis showed that preoperative PNI (48.5 vs 51.7; p < 0.01), revision status (p < 0.05), male sex (p < 0.01), body mass index (BMI) (p < 0.05), and usage of anticoagulant agents (p < 0.05) differed significantly between the SSI and non-SSI groups. Multivariate logistic regression analysis showed that preoperative PNI (odds ratio [OR], 0.94; 95% confidence interval [CI]: 0.90-0.98; p < 0.01), male sex (OR, 2.64; 95% CI: 1.40-4.99; p < 0.01), length of surgery ≥ 180 min (OR, 2.78; 95% CI: 1.30-5.96; p < 0.01), BMI ≥ 30 kg/m² (OR, 2.89; 95% CI: 1.20-6.97; p < 0.05), and revision status (OR, 2.30; 95% CI: 1.07-4.98; p < 0.05) were independently associated with SSI postoperatively.

CONCLUSION

Lower preoperative PNI was found to be a risk factor for SSI after spine surgery. Patients with lower preoperative PNI values should be cautioned about the risk of SSI and provide adequate informed consent.

Deep surgical site infection after posterior instrumented fusion for rheumatoid upper cervical subluxation treated with antibiotic-loaded bone cement: Three case reports

INTRODUCTION

Patients with rheumatoid arthritis (RA) tend to be immunosuppressed due to RA itself and the therapeutic drugs administered. The management of surgical site infection (SSI) following upper cervical spinal instrumented fusion in RA patients is challenging; however, literature on the treatment for such conditions is scarce. We report 3 consecutive patients with RA, who developed deep SSI following upper cervical posterior fusion and were treated using antibiotic-loaded bone cement (ALBC).

PATIENT CONCERNS

All 3 patients reported in the current study experienced compression myelopathy with upper cervical spinal deformity and received prednisolone and methotrexate for controlling RA preoperatively. The patient in Case 1 underwent C1-2 posterior fusion and developed deep SSI due to methicillin-sensitive Staphylococcus aureus at 3 months postoperatively; the patient in Case 2 underwent occipito-C2 posterior fusion and developed deep SSI due to methicillin-sensitive Staphylococcus aureus at 2 weeks postoperatively; and the patient in Case 3 underwent occipito-C2 posterior instrumented fusion and laminoplasty at C3-7, and developed deep SSI due to methicillin-resistant coagulase negative staphylococci at 3 weeks postoperatively.

DIAGNOSIS

All patients developed deep staphylococcal SSI in the postoperative period.

INTERVENTIONS

All 3 patients were treated using ALBC placed on and around the instrumentation to cover them and occupy the dead space after radical open debridement.

OUTCOMES

The deep infection was resolved uneventfully after the single surgical intervention retaining spinal instrumentation. Good clinical outcomes of the initial surgery were maintained until the final follow-up without recurrence of SSI in all 3 cases.

CONCLUSION

ALBC embedding spinal instrumentation procedure can be a viable treatment for curing SSI in complex cases, such as patients with RA who undergo high cervical fusion surgeries without implant removal.

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.

Intraoperative bacterial contamination in total hip and knee arthroplasty is associated with operative duration and peeling of the iodine-containing drape from skin

BACKGROUND

Surgical site infection (SSI) and periprosthetic joint infection are the most important problems after total hip arthroplasty (THA) and total knee arthroplasty (TKA). This study aimed to examine the risk factors for intraoperative bacterial contamination in THA and TKA.

METHODS

One hundred and seven hips underwent THA, while 74 knees underwent TKA. After the implant was placed, a swab sample for bacterial culture was collected around the skin incision. At the time of specimen collection, patients were separated into two groups based on whether the iodine-containing drape remained adhered to the skin (group DR) or the iodine-containing drape was peeled off (group ND). Patient characteristics, including age, height, body weight, body mass index, operative duration, intraoperative blood loss, surgical procedures, and condition of the iodine-containing drape, were compared between patients with positive and negative bacterial cultures.

RESULTS

In THA, which had a shorter operative duration than TKA (p < 0.001), there was one case of bacterial contamination. In TKA, there were ten cases of positive bacterial contamination, all in group ND. Postoperative SSI occurred in one case. The binomial logistic regression analyses confirmed that TKA [OR 16.562 (95% CI 2.071 to 132.430), p < 0.01] was a high risk factor of bacterial contamination compared to THA and the group ND [OR 0.000 (95% CI 0.000), p < 0.001] had a low risk of bacterial contamination compared to the group DR. In TKAs, operative duration was the risk factor of bacterial contamination [OR 1.026 (95% CI 1.000 to 1.054), p < 0.01].

CONCLUSIONS

Intraoperative bacterial contamination increases in procedures with long operating time and may be suppressed by proper use of an iodine-containing drape.

Care Bundle Approach to Reduce Surgical Site Infections in Acute Surgical Intensive Care Unit, Cairo, Egypt

Introduction

Surgical site infections (SSIs) are one of the most frequently reported hospital acquired infections associated with significant spread of antibiotic resistance.

Purpose

We aimed to evaluate a bundle-based approach in reducing SSI at acute surgical intensive care unit of the Emergency Hospital of Cairo University.

Patients and Methods

Our prospective study ran from March 2018 to February 2019 and used risk assessment. The study was divided into three phases. Phase I: (pre-bundle phase) for 5 months; data collection, active surveillance of the SSIs, screening for OXA-48 producing Enterobacteriaceae and multidrug resistant Acinetobacter baumannii colonizers using Chrom agars were carried out. Phase II: (bundle-implementation) a 6-S bundle approach included education, training and postoperative bathing with Chlorhexidine Gluconate in collaboration with the infection control team. Finally, Phase III: (post-implementation) for estimation of compliance, rates of colonization, and infection.

Results

Phase I encompassed 177 patients, while Phase III included 93 patients. A significant reduction of colonization from 24% to 15% (p<0.001) was observed. Similarly, a decrease of SSI from 27% to 15% (p=0.02) was noticed. A logistic regression was performed to adjust for confounding in the implementation of the bundle and we found a 70% reduction of SSI odd's ratio (OR's ratio = 0.3) confidence interval (95% CI 0.14-0.6) with significant Apache II (p=0.04), type of wound; type II (p=0.002), type III (p=0.001) and duration of surgery (p=0.04) as independent risk factors for SSI. Klebsiella pneumoniae was the most prevalent organism during phase I (34.7%). On the other hand, A. baumannii was the commonest organism to be isolated during phase III with (38.5%) preceding K. pneumoniae (30%).

Conclusion

Our study demonstrated that the implementation of a multidisciplinary bundle containing evidence-based interventions was associated with a significant reduction of colonization and SSIs and was met with staff approval and acceptable compliance.

Physical function computer adaptive test outcomes in diabetic lumbar spine surgical patients

BACKGROUND CONTEXT

Diabetes is a highly prevalent comorbid condition among patients undergoing spine surgery. Several studies have used legacy patient-reported outcome measures to implicate diabetes as a predictor of increased disability, pain, and decreased physical function and quality of life following spine surgery. The effect of diabetes on postoperative physical function has not yet been studied using the PROMIS Physical Function Computer Adaptive Test (PF CAT).

PURPOSE

To understand the effect of diabetes on physical function outcomes among patients undergoing lumbar spine surgery, as reported by the PF CAT.

STUDY DESIGN/SETTING

A retrospective cohort study was performed at a single university-based spine clinic.

PATIENT SAMPLE

Patients who underwent lumbar spine surgery between October 1, 2013 and April 26, 2018 with both PF CAT and Oswestry Disability Index (ODI) scores available for review.

OUTCOME MEASURES

PROMIS PF CAT. Secondary measures of disability included the ODI.

METHODS

PF CAT and ODI questionnaires were administered to patients via electronic tablets. Data from these questionnaires were collected prospectively, and retrieved from a university database. Wilcox tests, Exact Wilcox tests, linear regression models, and descriptive analytics were applied.

RESULTS

Patients meeting inclusion criteria included 233 nondiabetic patients and 65 diabetic patients. Mean PF CAT scores among diabetics were lower than those of nondiabetics at all time-points from preoperative through 12 months postoperative, with significance found at both 6 months (p=.035) and 12 months (p=.039) postoperative. Mean ODI scores among diabetics were significantly higher than those of nondiabetics at 3 months (p=.018) and 12 months (p=.027) postoperative. By 12 months postoperative, a smaller proportion of diabetics reached PF CAT and ODI minimum clinically important difference thresholds when compared to nondiabetics.

CONCLUSIONS

Diabetes is associated with lower PF CAT scores up to one year following lumbar spine surgery. However, many of these patients achieve meaningful improvement in physical function during this time. The PF CAT is consistent with legacy outcome measures in assessing outcomes in diabetic patients undergoing lumbar spine surgery, with an added benefit of decreased patient burden.

Multivariate analysis of incision infection after posterior lumbar surgery in diabetic patients: A single-center retrospective analysis

BACKGROUND

Patients requiring posterior lumbar surgery have increased annually. Incision infection after lumbar surgery has serious consequences for patients. However, data on the related factors of incision infection after lumbar surgery in diabetic patients are limited. Therefore, this study aimed to analyze diabetic patients who underwent lumbar surgery and to explore the risk factors of perioperative incision infection to provide a scientific basis for perioperative intervention of lumbar spine surgery and reduce risk of incision infection in such patients.

METHODS

We retrospectively reviewed data of diabetic patients who underwent posterior lumbar surgery from 2011 to 2016. A total of 523 diabetic patients undergoing posterior lumbar surgery were analyzed for the influence of various risk factors on postoperative incision infection. Univariate and multivariate logistic regression was performed. The test level was α=.05, and P < .05 was considered statistically significant.

RESULTS

In the past 6 years, among the 523 diabetic patients, the incidence of incision infection after posterior lumbar surgery was approximately 7.1%, of which the shallow incision infection rate was 4.2% and the deep incision infection rate was 2.9%. Incision infection of posterior lumbar surgery in diabetic patients is related to smoking, preoperative glycosylated hemoglobin A1c, postoperative albumin (Alb), surgical segment, operation time, and intraoperative blood loss, especially on postoperative fasting blood glucose, postoperative postprandial blood glucose, local subcutaneous fat thickness, and operation sequence (odds ratio >5.00). Meanwhile, sex, age, body mass index (BMI), preoperative Alb, and newly diagnosed diabetes were not highly correlated with incision infection after posterior lumbar surgery.

CONCLUSION

Local subcutaneous fat thickness is a better indicator for predicting incision infection compared with BMI. In diabetic patients undergoing lumbar surgery, actively controlling blood glucose fluctuations, restoring normal diet early after surgery, and optimizing surgical procedures to reduce trauma and operative time can effectively reduce the risk of infection after posterior lumbar surgery.

Body mass index and the risk of deep surgical site infection following posterior cervical instrumented fusion

BACKGROUND

Surgical site infection (SSI) following spine surgery is associated with increased morbidity, reoperation rates, hospital readmissions, and cost. The incidence of SSI following posterior cervical spine surgery is higher than anterior cervical spine surgery, with rates from 4.5% to 18%. It is well documented that higher body mass index (BMI) is associated with increased risk of SSI after spine surgery. There are only a few studies that examine the correlation of BMI and SSI after posterior cervical instrumented fusion (PCIF) using national databases, however, none that compare trauma and nontraumatic patients.

PURPOSE

The purpose of this study is to determine the odds of developing SSI with increasing BMI after PCIF, and to determine the risk of SSI in both trauma and nontraumatic adult patients.

STUDY DESIGN

This is a retrospective cohort study of a prospective surgical database collected at one academic institution.

PATIENT SAMPLE

The patient sample is from a prospectively collected surgical registry from one institution, which includes patients who underwent PCIF from April 2011 to October 2017.

OUTCOME MEASURES

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

METHODS

This is a retrospective cohort study using a prospectively collected database of all spine surgeries performed at our institution from April 2011 to October 2017. We identified 1,406 patients, who underwent PCIF for both traumatic injuries and nontraumatic pathologies using International Classification of Diseases 9 and 10 procedural codes. Thirty-day readmission data were obtained. Patient's demographics, BMI, presence of diabetes, preoperative diagnosis, and surgical procedures performed were identified. Using logistic regression analysis, the risk of SSI associated with every one-unit increase in BMI was determined. This study received no funding. All the authors in this study report no conflict of interests relevant to this study.

RESULTS

Of the 1,406 patients identified, 1,143 met our inclusion criteria. Of those patients, 688 had PCIF for traumatic injuries and 454 for nontraumatic pathologies. The incidence of SSI for all patients, who underwent PCIF was 3.9%. There was no significant difference in the rate of SSI between our trauma group and nontraumatic group. There was a higher rate of infection in patients, who were diabetic and with BMI≥30 kg/m². The presence of both diabetes and BMI≥30 kg/m² had an added effect on the risk of developing SSI in all patients, who underwent PCIF. Additionally, logistic regression analysis showed that there was a positive difference measure between BMI and SSI. Our results demonstrate that for one-unit increase in BMI, the odds of having a SSI is 1.048 (95% CI: 1.007-1.092, p=.023).

CONCLUSIONS

Our study demonstrates that our rate of SSI after PCIF is within the range of what is cited in the literature. Interestingly, we did not see a statistically significant difference in the rate of infection between our trauma and nontrauma group. Overall, diabetes and elevated BMI are associated with increased risk of SSI in all patients, who underwent PCIF with even a higher risk in patient, who are both diabetic and obese. Obese patients should be counseled on elevated SSI risk after PCIF, and those with diabetes should be medically optimized before and after surgery when possible to minimize SSI.

Atopic dermatitis is a novel demographic risk factor for surgical site infection after anterior cruciate ligament reconstruction

PURPOSE

Although various risk factors for surgical site infection after anterior cruciate ligament reconstruction (ACLR) have been reported, the number of studies with large sample sizes on this topic is limited. The aim of the present study was to clarify the risk factors for early surgical site infection after ACLR in a large cohort using a national database in Japan.

METHODS

The data of patients who underwent ACLR from 2010 to 2015 were obtained from the Diagnosis Procedure Combination database, which covers approximately half of all hospital admissions in Japan. The outcome measures were the prevalences of surgical site infection and deep surgical site infection after ACLR during hospitalization. The association between the occurrence of surgical site infection and patients' demographic data, including sex, age, body mass index (BMI), smoking status, preoperative steroid use, and comorbidities such as diabetes, hepatic dysfunction, renal dysfunction, and atopic dermatitis, were examined using a multivariable logistic regression model.

RESULTS

Among 30,536 patients who underwent ACLR, 288 patients with surgical site infection (0.94%) and 86 with deep surgical site infection (0.28%) were identified. The univariate analysis showed that higher prevalences of surgical site infection and deep surgical site infection were associated with male sex, a higher BMI, atopic dermatitis, and preoperative steroid use. Patients with diabetes or hepatic dysfunction had a significantly higher prevalence of surgical site infection. The multivariable analysis showed that surgical site infection was significantly associated with male sex vs. female sex; odds ratio (OR), 2.90; 95% confidence interval (CI), 2.17-3.89, age of ≤ 19 vs. 20-29 years; OR, 1.56; 95% CI 1.13-2.15, BMI of ≥ 30.0 vs. 18.5-22.9 kg/m²; OR, 1.72; 95% CI 1.16-2.54, diabetes (OR, 2.70; 95% CI 1.28-5.71), atopic dermatitis (OR, 7.19; 95% CI 2.94-17.57), and preoperative steroid use (OR, 6.18; 95% CI 2.32-16.52).

CONCLUSION

Atopic dermatitis, preoperative steroid use, young age (≤ 19 years), obesity (BMI of ≥ 30.0 kg/m²), male sex, and diabetes were independent demographic risk factors for surgical site infection after ACLR. The present study will be useful when surgeons evaluate the risk of SSI after ACLR in terms of demographic aspects.

LEVEL OF EVIDENCE

III.

Risk Factors for Perioperative Complications in Morbidly Obese Patients Undergoing Elective Posterior Lumbar Fusion

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

The prevalence of obesity-related low back pain and degenerative disc disease is on the rise. Past studies have demonstrated that obesity is associated with higher perioperative complication rates, but there remains a gap in the literature regarding additional risk factors that further predispose this already high-risk patient population to poor surgical outcomes following elective posterior lumbar fusion (PLF). The aim of the study is to identify independent risk factors for poor 30-day perioperative outcomes in morbidly obese patients undergoing elective PLF.

METHODS

We identified 22 909 patients in the American College of Surgeons National Surgical Quality Improvement Program database who underwent elective PLF. There were 1861 morbidly obese patients. Baseline patient demographics and medical comorbidities were collected. Univariate analysis was performed to compare perioperative complication rates between non-morbidly obese and morbidly obese patients. The 5 most common complications in the morbidly obese group were then selected for multivariate regression analysis to identify independent risk factors for poor 30-day outcomes.

RESULTS

Morbidly obese patients had a higher perioperative complication rate. The 5 most common complications were prolonged hospitalization, blood transfusion, readmission, wound complications, and reoperation. Independent risk factors for these complications were age ≥65 years, super obesity (ie, BMI > 48.6), chronic steroid use, American Society of Anesthesiology classification ≥3, poor functional status, long length of fusion ≥4 levels, and extended operative time (ie, operative time ≥318 minutes).

CONCLUSIONS

Morbidly obese patients are at higher risk of perioperative complications following elective PLF. Modifiable risk factors for the most common complications are obesity and preoperative steroid use.

Surgical Site Infection in Spine Surgery: Who Is at Risk?

STUDY DESIGN

Retrospective literature review of spine surgical site infection (SSI).

OBJECTIVE

To perform a review of SSI risk factors and more specifically, categorize them into patient and surgical factors.

METHODS

A review of published literature on SSI risk factors in adult spine surgery was performed. We included studies that reported risk factors for SSI in adult spinal surgery. Excluded are pediatric patient populations, systematic reviews, and meta-analyses. Overall, we identified 72 cohort studies, 1 controlled-cohort study, 1 matched-cohort study, 1 matched-paired cohort study, 12 case-controlled studies (CCS), 6 case series, and 1 cross-sectional study.

RESULTS

Patient-associated risk factors-diabetes mellitus, obesity (body mass index >35 kg/m²), subcutaneous fat thickness, multiple medical comorbidities, current smoker, and malnutrition were associated with SSI. Surgical associated factors-preoperative radiation/postoperative blood transfusion, combined anterior/posterior approach, surgical invasiveness, or levels of instrumentation were associated with increased SSI. There is mixed evidence of age, duration of surgery, surgical team, intraoperative blood loss, dural tear, and urinary tract infection/urinary catheter in association with SSI.

CONCLUSION

SSIs are associated with many risk factors that can be patient or surgically related. Our review was able to identify important modifiable and nonmodifiable risk factors that can be essential in surgical planning and discussion with patients.

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.

The development of a staphylococcus aureus four antigen vaccine for use prior to elective orthopedic surgery

Staphylococcus aureus (S. aureus) is a challenging bacterial pathogen which can cause a range of diseases, from mild skin infections, to more serious and invasive disease including deep or organ space surgical site infections, life-threatening bacteremia, and sepsis. S. aureus rapidly develops resistance to antibiotic treatments. Despite current infection control measures, the burden of disease remains high. The most advanced vaccine in clinical development is a 4 antigen S. aureus vaccine (SA4Ag) candidate that is being evaluated in a phase 2b/3 efficacy study in patients undergoing elective spinal fusion surgery (STaphylococcus aureus suRgical Inpatient Vaccine Efficacy [STRIVE]). SA4Ag has been shown in early phase clinical trials to be generally safe and well tolerated, and to induce high levels of bactericidal antibodies in healthy adults. In this review we discuss the design of SA4Ag, as well as the proposed clinical development plan supporting licensure of SA4Ag for the prevention of invasive disease caused by S. aureus in elective orthopedic surgical populations. We also explore the rationale for the generalizability of the results of the STRIVE efficacy study (patients undergoing elective open posterior multilevel instrumented spinal fusion surgery) to a broad elective orthopedic surgery population due to the common pathophysiology of invasive S. aureus disease and commonalties of patient and procedural risk factors for developing postoperative S. aureus surgical site infections.

Decreased rate of surgical site infection after spinal surgery with instrumentation using bundled approach including surveillance and intrawound vancomycin application

Surgical site infections (SSIs) increase the risk of mortality, postsurgery, extend hospital stay, and increase the costs of healthcare. Our aim in this study was to evaluate the effectiveness of a multidisciplinary, evidence-based, surveillance program combined with intrawound application of vancomycin in lowering the incidence rate of SSI after spinal surgery with instrumentation.We conducted a retrospective analysis of 637 patients who underwent spinal fusion with instrumentation in our institution at 3 different time periods: prior to our surveillance program (control group), surveillance only (surveillance group 1), and surveillance combined with intrawound vancomycin application (surveillance group 2). The following covariates were considered in the evaluation of between-group differences in SSI rate: sex, age, surgical site, National Nosocomial Infection Surveillance (NNIS) risk index, American Society of Anesthesiologists (ASA) physical status classification, and other health comorbidities. The causative organism in cases of SSI was confirmed in all cases.The rate of SSI was significantly lower in the surveillance group 2 (1.4%) than in the control group (4.6%; P = .04). On multivariate logistic regression analysis, steroid use (adjusted odd's ratio (OR), 6.06; 95% confidence interval (CI), 1.45-23.6) and operative time (adjusted OR.1.01; 95% CI, 1.00-1.01) were identified as independent risk factors of SSI. Staphylococcus species and Propionibacterium acnes were the principal causative organisms.A bundled approach that includes surveillance and intrawound application of vancomycin is an effective strategy to lower the risk of SSI after spinal fusion with instrumentation. The use of steroid and longer operative time are risk factors of SSI.Our findings support the implementation of a program of surveillance, combined with intrawound vancomycin application, to reduce the incidence rate of SSIs in spinal surgery.

Incidence and risk factors for infection in spine surgery: A prospective multicenter study of 1764 instrumented spinal procedures

BACKGROUND

Surgical site infection (SSI) is a common complication in spinal surgery, imposing a high burden on patients and society. However, information about its characteristics and related risk factors is limited. We designed this prospective, multicenter study to address this issue.

METHODS

From January 2015 through February 2016, a total of 1764 patients who had spinal trauma or degenerative spinal diseases were treated with instrumented surgeries and followed up for 1 year with complete data. Data on all patients were abstracted from electronic medical records, and SSIs were prospectively inspected and diagnosed by surgeons in our department. Any disagreement among them was settled by the leader of this study. SPSS 19.0 was used to perform the analyses.

RESULTS

A total of 58 patients (3.3%, 58 of 1764) developed SSI; 1.1% had deep SSI, and 2.2% had superficial SSI. Of these, 60.6% (21 of 33) had a polymicrobial cause. Most of them (51 of 58) occurred during hospitalization. The median occurrence time was 3 days after operation (range: 1-123 days). SSI significantly prolonged hospital stays, by 9.3 days on average. The univariate analysis revealed reason for surgery as the only significant risk factor. The multivariate analysis, however, revealed 8 significant risk factors, including higher BMI, surgical site (cervical), surgical approach (posterior), surgery performed in summer, reasons for surgery (degenerative disease), autograft for fusion and fixation, and higher preoperative platelet level.

CONCLUSION

Identification of these risk factors aids in stratifying preoperative risk to reduce SSI incidence. In addition, the results could be used in counseling patients and their families during the consent process.

Prolonged Operative Duration Increases Risk of Surgical Site Infections: A Systematic Review

Background: The incidence of surgical site infection (SSI) across surgical procedures, specialties, and conditions is reported to vary from 0.1% to 50%. Operative duration is often cited as an independent and potentially modifiable risk factor for SSI. The objective of this systematic review was to provide an in-depth understanding of the relation between operating time and SSI.

Patients and Methods: This review included 81 prospective and retrospective studies. Along with study design, likelihood of SSI, mean operative times, time thresholds, effect measures, confidence intervals, and p values were extracted. Three meta-analyses were conducted, whereby odds ratios were pooled by hourly operative time thresholds, increments of increasing operative time, and surgical specialty.

Results: Pooled analyses demonstrated that the association between extended operative time and SSI typically remained statistically significant, with close to twice the likelihood of SSI observed across various time thresholds. The likelihood of SSI increased with increasing time increments; for example, a 13%, 17%, and 37% increased likelihood for every 15 min, 30 min, and 60 min of surgery, respectively. On average, across various procedures, the mean operative time was approximately 30 min longer in patients with SSIs compared with those patients without.

Conclusions: Prolonged operative time can increase the risk of SSI. Given the importance of SSIs on patient outcomes and health care economics, hospitals should focus efforts to reduce operative time.

Global Forum: The Burden of Bone and Joint Infections: A Growing Demand for More Resources

The rate and severity of septic complications following joint replacement surgery and the incidence of posttraumatic infections are projected to increase at a faster pace because of a tendency to operate on high-risk patients, including older patients, patients with diabetes, and patients who are immunocompromised or have comorbidities. Musculoskeletal infections are devastating adverse events that may become life-threatening conditions. They create an additional burden on total health-care expenditures, and can lead to functional impairment, long-lasting disability, or even permanent handicap, with the inevitable social and economic burdens. The scientific community should take a more active role to draw public attention to the plight of hundreds of thousands of people across the globe who experience complications, become disabled, and, in some cases, die, and it should highlight what could be achieved if the global community takes decisive steps to improve access, early detection, and appropriate care. However, mitigating the adverse personal, clinical, and socioeconomic effects of these conditions requires increasing financial resources provided by both governments and funding organizations. Furthermore, a targeted action plan from the providers and the professional societies should be put in place so that the burden created by bone and joint infections is included in the agenda for global health-care priorities.

Smoking and Risk of Surgical Site Infection after Spinal Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

The effect of smoking on the risk of surgical site infection (SSI) after spinal surgery remains controversial. Therefore, we conducted a meta-analysis to determine whether there is an association between smoking and the risk of SSI and to calculate the relative risk of infections attributable to smoking.

METHODS

We performed a literature search of cohort and case-control studies in the MEDLINE, Embase, and ISI Web of Science databases. Sensitivity and subgroup analyses were performed to test the robustness of overall estimates of risk and to investigate potential sources of heterogeneity. We further calculated the population-attributable fraction (PAF) to evaluate the proportion of SSIs associated with smoking.

RESULTS

In total, 26 independent observational studies involving 67,405 patients who underwent spinal surgery were analyzed. Smokers had a significantly higher risk of SSI than did nonsmokers (odds ratio [OR] 1.26; 95% confidence interval [CI] 1.05-1.51). Subgroup analysis according to the study design revealed an apparent association between smoking and SSI in the cohort subgroup (OR 1.40; 95% CI 1.17-1.66), but not in the case-control subgroup (OR 0.99; 95% CI 0.64-1.53). After evaluation of the PAF, the proportion of SSIs associated with smoking increased to 10.37%.

CONCLUSIONS

This meta-analysis demonstrated that smoking increases the risk of SSI after spinal surgery. False-negative associations in other studies may have resulted from defects in the study design. However, because of the heterogeneity among the studies in the present meta-analysis, the results should be interpreted with caution.

Burden of Surgical Site Infections Associated with Select Spine Operations and Involvement of Staphylococcus aureus

BACKGROUND

Spine operations may be indicated for treatment of diseases including vertebral injuries, degenerative spinal conditions, disk disease, spinal misalignments, or malformations. Surgical site infection (SSI) is a clinically important complication of spine surgery. Staphylococcus aureus, including methicillin-resistant Staphylococcus aureus (MRSA), is a leading cause of post-spinal SSIs.

METHODS

PubMed and applicable infectious disease conference proceedings were searched to identify relevant published studies. Overall, 343 full-text publications were screened for epidemiologic, mortality, health care resource utilization, and cost data on SSIs associated with specified spine operations.

RESULTS

Surgical site infection rates were identified in 161 studies from North America, Europe, and Asia. Pooled average SSI and S. aureus SSI rates for spine surgery were 1.9% (median, 3.3%; range, 0.1%-22.6%) and 1.0% (median, 2.0%; range, 0.02%-10.0%). Pooled average contribution of S. aureus infections to spinal SSIs was 49.3% (median, 50.0%; range, 16.7%-100%). Pooled average proportion of S. aureus SSIs attributable to MRSA was 37.9% (median, 42.5%; range, 0%-100%). Instrumented spinal fusion had the highest pooled average SSI rate (3.8%), followed by spinal decompression (1.8%) and spinal fusion (1.6%). The SSI-related mortality rate among spine surgical patients ranged from 1.1%-2.3% (three studies). All studies comparing SSI and control cohorts reported longer hospital stays for patients with SSIs. Pooled average SSI-associated re-admission rate occurring within 30 d from discharge ranged from 20% to 100% (four studies). Pooled average SSI-related re-operation rate was 67.1% (median, 100%; range, 33.5%-100%). According to two studies reporting direct costs, spine surgical patients incur approximately double the health care costs when they develop an SSI.

CONCLUSIONS

Available published studies demonstrate a clinically important burden of SSIs related to spine operations and the substantial contribution of S. aureus (including MRSA). Preventive strategies aimed specifically at S. aureus SSIs could reduce health care costs and improve patient outcomes for spine operations.

Decompressive Laminectomy Complicated by Postoperative Mycoplasma hominis Epidural Abscess and Meningitis in a Young Woman: A Case Report

CASE

A twenty-eight-year-old woman underwent decompressive laminectomy and placement of an interlaminar stabilizer due to L4/L5 disc herniation. Thirteen days later she developed a fever unresponsive to meropenem and vancomycin, along with signs of meningitis. A Mycoplasma hominis epidural abscess was identified. She had no preoperative risk factors for extragenital M. hominis infection, but had had a urinary catheter inserted intraoperatively.

CONCLUSION

M. hominis postoperative surgical site infection is a rarely identified complication of spinal surgery. Seeding from the genitourinary tract is the most likely source.

Obesity is associated with increased postoperative complications after operative management of tibial shaft fractures

OBJECTIVES

To assess the association of obesity and postoperative complications after operative management of tibial shaft fractures.

METHODS

Patients who underwent operative management of a tibial shaft fracture were identified in a national database by Current Procedural Terminology (CPT) codes for: (1) open reduction and internal fixation (ORIF) and (2) intramedullary nailing (IMN) procedures in the setting of International Classification of Diseases, Ninth Revision (ICD-9) codes for tibial shaft fracture. These groups were then divided into non-obese, obese, and morbidly obese cohorts using ICD-9 codes. Each cohort was then assessed for grouped complications within 90 days, removal of implants within 6 months, and nonunion within 9 months postoperatively. Odds ratios and 95% confidence intervals were calculated.

RESULTS

From 2005 to 2012, 14,638 patients who underwent operative management of tibial shaft fractures were identified, including 4425 (30.2%) ORIF and 10,213 (69.8%) IMN. Overall, 1091 patients (7.4%) were coded as obese and 820 (5.6%) morbidly obese. In each operative group, obesity and morbid obesity was associated with a substantial increase in the rate of major and minor medical complications, venous thromboembolism, infection, procedures for implant removal, and nonunion.

CONCLUSIONS

In patients who undergo either ORIF or IMN for tibial shaft fractures, obesity and its related medical comorbidities are associated with significantly increased rates of postoperative medical complications, infection, nonunion, and implant removal compared to non-obese patients.