Risk factors for surgical site infection after posterior cervical spine surgery: an analysis of 5,441 patients from the ACS NSQIP 2005-2012

The Evolution of Risk Assessment in Spine Surgery: A Narrative Review

BACKGROUND

Risk assessment is critically important in elective and high-risk interventions, particularly spine surgery. This narrative review describes the evolution of risk assessment from the earliest instruments focused on general surgical risk stratification, to more accurate and spine-specific risk calculators that quantified risk, to the current era of big data.

METHODS

The PubMed and SCOPUS databases were queried on October 11, 2023 using search terms to identify risk assessment tools (RATs) in spine surgery. A total of 108 manuscripts were included after screening with full-text review using the following inclusion criteria: 1) study population of adult spine surgical patients, 2) studies describing validation and subsequent performance of preoperative RATs, and 3) studies published in English.

RESULTS

Early RATs provided stratified patients into broad categories and allowed for improved communication between physicians. Subsequent risk calculators attempted to quantify risk by estimating general outcomes such as mortality, but then evolved to estimate spine-specific surgical complications. The integration of novel concepts such as invasiveness, frailty, genetic biomarkers, and sarcopenia led to the development of more sophisticated predictive models that estimate the risk of spine-specific complications and long-term outcomes.

CONCLUSIONS

RATs have undergone a transformative shift from generalized risk stratification to quantitative predictive models. The next generation of tools will likely involve integration of radiographic and genetic biomarkers, machine learning, and artificial intelligence to improve the accuracy of these models and better inform patients, surgeons, and payers.

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.

The frailty-driven predictive model for failure to rescue among patients who experienced a major complication following cervical decompression and fusion: an ACS-NSQIP analysis of 3,632 cases (2011-2020)

BACKGROUND CONTEXT

Preoperative risk stratification for patients considering cervical decompression and fusion (CDF) relies on established independent risk factors to predict the probability of complications and outcomes in order to help guide pre and perioperative decision-making.

PURPOSE

This study aims to determine frailty's impact on failure to rescue (FTR), or when a mortality occurs within 30 days following a major complication.

STUDY DESIGN/SETTING

Cross-sectional retrospective analysis of retrospective and nationally-representative data.

PATIENT SAMPLE

The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was queried for all CDF cases from 2011-2020.

OUTCOME MEASURES

CDF patients who experienced a major complication were identified and FTR was calculated as death or hospice disposition within 30 days of a major complication.

METHODS

Frailty was measured by the Risk Analysis Index-Revised (RAI-Rev). Baseline patient demographics and characteristics were compared for all FTR patients. Significant factors were assessed by univariate and multivariable regression for the development of a frailty-driven predictive model for FTR. The discriminative ability of the predictive model was assessed using a receiving operating characteristic (ROC) curve analysis.

RESULTS

There were 3632 CDF patients who suffered a major complication and 7.6% (277 patients) subsequently expired or dispositioned to hospice, the definition of FTR. Independent predictors of FTR were nonelective surgery, frailty, preoperative intubation, thrombosis or embolic complication, unplanned intubation, on ventilator for >48 hours, cardiac arrest, and septic shock. Frailty, and a combination of preoperative and postoperative risk factors in a predictive model for FTR, achieved outstanding discriminatory accuracy (C-statistic = 0.901, CI: 0.883-0.919).

CONCLUSION

Preoperative and postoperative risk factors, combined with frailty, yield a highly accurate predictive model for FTR in CDF patients. Our model may guide surgical management and/or prognostication regarding the likelihood of FTR after a major complication postoperatively with CDF patients. Future studies may determine the predictive ability of this model in other neurosurgical patient populations.

Performance of a Large Language Model in the Generation of Clinical Guidelines for Antibiotic Prophylaxis in Spine Surgery

OBJECTIVE

Large language models, such as chat generative pre-trained transformer (ChatGPT), have great potential for streamlining medical processes and assisting physicians in clinical decision-making. This study aimed to assess the potential of ChatGPT's 2 models (GPT-3.5 and GPT-4.0) to support clinical decision-making by comparing its responses for antibiotic prophylaxis in spine surgery to accepted clinical guidelines.

METHODS

ChatGPT models were prompted with questions from the North American Spine Society (NASS) Evidence-based Clinical Guidelines for Multidisciplinary Spine Care for Antibiotic Prophylaxis in Spine Surgery (2013). Its responses were then compared and assessed for accuracy.

RESULTS

Of the 16 NASS guideline questions concerning antibiotic prophylaxis, 10 responses (62.5%) were accurate in ChatGPT's GPT-3.5 model and 13 (81%) were accurate in GPT-4.0. Twenty-five percent of GPT-3.5 answers were deemed as overly confident while 62.5% of GPT-4.0 answers directly used the NASS guideline as evidence for its response.

CONCLUSION

ChatGPT demonstrated an impressive ability to accurately answer clinical questions. GPT-3.5 model's performance was limited by its tendency to give overly confident responses and its inability to identify the most significant elements in its responses. GPT-4.0 model's responses had higher accuracy and cited the NASS guideline as direct evidence many times. While GPT-4.0 is still far from perfect, it has shown an exceptional ability to extract the most relevant research available compared to GPT-3.5. Thus, while ChatGPT has shown far-reaching potential, scrutiny should still be exercised regarding its clinical use at this time.

Effects of Preoperative Glucocorticoid Use on Patients Undergoing Single-Level Lumbar Fusions: A Retrospective Propensity Score-Matched Registry Study

Objective Spinal fusions are gaining popularity as a means of treating spinal deformity and instability from a range of pathologies. The prevalence of glucocorticoid use has also increased in recent decades, and their systemic effects are well-documented. Although commonly used in the preoperative period, the effects of steroids on outcomes among patients undergoing spinal fusions are inadequately described. This study compares the odds of developing complications among patients who underwent single-level lumbar fusions with and without preoperative glucocorticoid use in hopes of establishing more evidence-based parameters for guiding preoperative steroid use. Methods The TriNetX multi-institutional electronic health record database was used to perform a retrospective, propensity score-matched analysis of clinical outcomes of two cohorts of patients who underwent posterior or posterolateral single-level lumbar fusions with and without interbody fusion, those who used glucocorticoids for at least one week within a year of fusion and those who did not. The outcomes of interest were examined within 30 days of the operation and included death, reoperation, deep or superficial surgical site infection (SSI), pneumonia, reintubation, ventilator dependence, tracheostomy, acute kidney injury (AKI), renal insufficiency, pulmonary embolism (PE) or deep venous thrombosis (DVT), urinary tract infection (UTI), emergency department (ED) visit, sepsis, and myocardial infarction (MI). Results The odds of developing pneumonia within 30 days of spinal fusion in the cohort that used glucocorticoids within one year of operation compared to the cohort without glucocorticoid use was 0.67 (p≤0.001, 95% CI: 0.59-0.69). The odds of requiring a tracheostomy within 30 days of spinal fusion in the cohort that used glucocorticoids within one year of operation compared to the cohort without glucocorticoid use was 0.39 (p≤0.001, 95% CI: 0.26-0.60). The odds of reoperation, deep and superficial SSI, and ED visits within 30 days of operation were significantly higher for the same glucocorticoid-receiving cohort, with odds ratios of 1.4 (p=0.003, 95% CI: 1.11-1.65), 1.86 (p≤0.001, 95% CI: 1.31-2.63), 2.28 (p≤0.001, 95% CI: 1.57-3.31), and 1.25 (p≤0.001, 95% CI: 1.17-1.33), respectively. After propensity score-matching, there was no significant difference between the odds of death, DVT, PE, MI, UTI, AKI, sepsis, reintubation, and ventilator dependence between the two cohorts. Conclusion In support of much of the current literature regarding preoperative glucocorticoid use and rates of complications, patients who underwent a single-level lumbar fusion and have used glucocorticoids for at least a week within a year of operation experienced significantly higher odds of reoperation, deep and superficial SSI, and ED visits. However, these patients using glucocorticoids were also found to have lower odds of developing pneumonia, renal insufficiency, and tracheostomy requirement than those who did not use steroids within a year of surgery.

The incidence of reoperation for pseudarthrosis after cervical spine surgery

INTRODUCTION

Pseudarthrosis after cervical spine surgery represents an underreported and challenging complication. Using a large multi-center surgical database, we sought to: (1) report the incidence of cervical pseudarthrosis, (2) evaluate changes in rates of cervical pseudarthrosis, and (3) describe risk factors for suboptimal outcomes after cervical pseudarthrosis surgery.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program database from 2012 to 2019 was used. The primary outcome was occurrence of a cervical fusion procedure with a prior diagnosis of pseudarthrosis. Fusion for pseudarthrosis was divided into anterior and posterior approaches. Post-operative complications were classified as major or minor. Prolonged LOS was defined as exceeding the 75th percentile for total hospital stay.

RESULTS

A total of 780 patients underwent cervical fusion for pseudarthrosis, and a significant increase in rates of surgery for pseudarthrosis was seen (0.25-1.2%, p < 0.001). The majority of cervical pseudarthrosis was treated with a posterior approach (66.5%). Postoperatively, 38 (4.9%) patients suffered a complication and 247 (31.7%) had a prolonged LOS. The three strongest risk factors for complications and extended LOS were > 10% weight loss preoperatively, congestive heart failure, and pre-operative bleeding disorder.

CONCLUSION

Results from a large multi-center national database revealed that surgery to treat cervical pseudarthrosis has increased from 2012 to 2019. Most pseudarthrosis was treated with a posterior approach. Reoperation to treat cervical pseudarthrosis carried risk, with 5% having complications and 32% having an extended LOS. These results lay the groundwork for a future prospective study to discern the true incidence of cervical pseudarthrosis and how to best avoid its occurrence.

Comparison between gravity drainage group and suction drainage group after cervical laminoplasty: a retrospective STROBE-compliant cohort study

OBJECTIVES

A retrospective study was conducted to compare gravity drainage and suction drainage after cervical laminoplasty.

PATIENTS AND METHODS

A total of 375 patients who underwent laminoplasty between January 2011 and December 2015 were engaged in this analysis. We investigated the patients' basic characteristics, drainage characteristics and postoperative complications.

RESULTS

During the initial 24 h after laminoplasty, the drainage volume in the suction drainage group was 177.31 ± 92.02 mL, and the drainage volume in the gravity drainage group was 133.33 ± 92.40 mL. The drainage volume showed significant difference (p < 0.01). The total drainage volume was 357.49 ± 195.16 mL and 250.16 ± 27.44 mL in the suction drainage group and gravity drainage group, respectively. The total drainage volume between the two groups was statistically different (p = 0.03). The postoperative Hb was significantly different between the gravity group and suction group on the first day after the operation (108.37 ± 23.92 mL vs. 87.32 ± 21.53 mL, p = 0.02). The number of patients required blood transfusion was significantly different between the two groups as well (p = 0.04). Two cases had symptomatic epidural hematomas (SEH) after laminoplaty. However, the occurrence of SEH among the two groups was not different significantly. Twelve patients had surgical site infection (SSI). Of these 12, nine had applied gravity drainage and three suction drainage. The rate of SSI was similar between the two groups (p = 0.71).

CONCLUSION

The initial 24 h' drainage volume and the total drainage volume increased significantly in the suction drainage group. The postoperative Hb was lower in the suction group than the gravity drainage group the first postoperative day. More patients needed blood transfusion if suction drainage was performed. The application of suction drainage cannot decrease the incidence of SSI and SEH after laminoplasty. Gravity drainage is recommended for laminoplasty.

Association between malnutrition and surgical site wound infection among spinal surgery patients: A meta-analysis

A surgical site infection (SSI) is one of the most common complications of spinal surgery. Malnutrition has also been linked to SSI after other surgical procedures. However, whether malnutrition is a risk factor for SSI after spinal surgery remains controversial. Therefore, we performed a meta-analysis to comprehensively evaluate the relationship between malnutrition and SSI. Relevant studies of the correlation between malnutrition and SSI were retrieved from the Cochrane Library, EMBASE, PubMed, Web of Science, China National Knowledge Infrastructure and Wanfang Data from database inception to 21 May 2023. Two reviewers independently assessed the included studies, and a meta-analysis was performed using STATA 17.0 software. A total of 24 articles with 179 388 patients were included: 3919 and 175 469 cases comprised the SSI and control groups, respectively. The meta-analysis results showed that malnutrition significantly increased the SSI incidence (odds ratio, 1.811; 95% confidence interval, 1.512-2.111; p < 0.001). These results suggest that patients with malnutrition are at higher risk for SSI after surgery. However, because of significant differences in sample sizes among studies, and because some studies had limitations to their methodological quality, further validation of these results by additional high-quality studies with larger sample sizes is necessary.

Unplanned readmissions following ambulatory spine surgery: assessing common reasons and risk factors

BACKGROUND CONTEXT

Although outpatient spine surgery is becoming increasingly popular in the United States, unplanned readmission following outpatient surgery remains a significant postoperative concern.

PURPOSE

This study aimed to (1) describe the incidence and timing of 30-day unplanned readmission after ambulatory lumbar and cervical spine surgery (2) evaluate the common reasons for readmission, and (3) identify factors associated with readmission in this population.

STUDY DESIGN/SETTING

Retrospective cohort study.

PATIENT SAMPLE

Patients who underwent ambulatory cervical or lumbar spine surgery between 2015 and 2020 were identified in the National Surgical Quality Improvement Program (NSQIP) database.

OUTCOME MEASURES

Hospital readmission within 30 postoperative days.

METHODS

Patients who underwent ambulatory cervical or lumbar spine surgery between 2015 and 2020 were identified using the National Surgical Quality Improvement Program (NSQIP) database. Reasons for and timing of unplanned readmissions were recorded. Multivariable poisson regressions were employed to determine any independent predictors of readmission.

RESULTS

A total of 33,092 ambulatory cervical and 68,115 ambulatory lumbar spine surgery patients were identified. Incidences of 30-day readmission were 3.37% and 3.07% among cervical and lumbar patients, respectively. The most common surgical site-related reasons for readmission included uncontrolled pain, recurrence of disc herniation or major symptom, and postoperative hematoma/seroma. Common nonsurgical site-related reasons included gastrointestinal, neurological, and cardiovascular complications. Factors associated with readmission among cervical patients included age ≥55, BMI ≥35, functional dependence, diabetes, smoking, COPD, and steroid use, whereas factors associated with readmission following lumbar spine surgery included age ≥65, female sex, BMI ≥35, functional dependence, ASA ≥3, diabetes, smoking, COPD, and hypertension (p<.05 for all).

CONCLUSION

This study highlights the common reasons and factors associated with unplanned readmission following ambulatory spine surgery. Consideration of these factors may be critical to ensuring appropriate patient selection for ambulatory spine surgery.

Incidence and risk factors of surgical site infection following cervical laminoplasty: A retrospective clinical study

There are many debates regarding the risk factors of surgical site infection (SSI) following posterior cervical surgery in previous studies. And, till now there is no such a study to examine cervical laminoplasty surgery. From January 2011 through October 2021, a total of 405 patients who were treated with unilateral open-door laminoplasty surgeries were enrolled in this study. We divided the patients into the SSI group and the non-SSI group and compared their patient-specific and procedure-specific factors. Univariate and multiple logistic regression analysis were performed to determine the risk factors. Of the 405 patients, 20 patients had SSI. The rate of SSI found to be 4.93%. There were significant differences between groups in the thicker subcutaneous fat thickness (FT) (p < 0.001), the higher ratio of subcutaneous FT to muscle thickness (MT) (p < 0.001), the higher preoperative Japanese Orthopaedic Association (JOA) Scores (p < 0.003), the decreased preoperative serum albumin (p < 0.001), the more postoperative drainage (p < 0.05) and the longer time of draining (p < 0.001). Logistic regression analysis of these differences showed that the higher ratio of subcutaneous FT/MT, the higher preoperative JOA scores, the decreased preoperative serum albumin and the longer time of draining were significantly related to SSI (p < 0.05). The higher ratio of subcutaneous FT/MT, the higher preoperative JOA scores, the decreased preoperative serum albumin and the longer time of draining are identified as the independent risk factors of SSI in cervical laminoplasty. Identification of these risk factors could be useful in reducing the SSI incidence and patients counselling.

Association of preoperative hypoprotein malnutrition with spinal postoperative complications and other conditions: A systematic review and meta-analysis

BACKGROUND

Postoperative complications of spinal surgery are a common clinical problem, which impose significant economic and clinical burdens on patients and medical staff. Previous studies have suggested a close relationship between low-protein malnutrition and postoperative complications of surgery. However, the relationship between preoperative malnutrition and various orthopedic postoperative complications remains unclear.

PURPOSE

To investigate the association between protein malnutrition and postoperative complications and outcomes.

METHODS

We conducted a systematic search of the PubMed, Embase, Cochrane Library, and Web of Science databases for published research articles between the database inception and February 28th, 2023, that evaluated the association between malnutrition and the risk of postoperative complications and death in spinal surgery patients. Malnutrition was defined as low pre-albumin and albumin levels before surgery. Two evaluators independently extracted study data and assessed the risk of bias in each study. Fixed- or random-effect models were used to calculate the pooled effect estimates. Funnel plots and Egger's tests were used to detect publication bias, and the Trim-and -Fill method was conducted to evaluate the impact of publication bias on the results.

RESULTS

A total of 26 studies were included in this meta-analysis, comprising 17 retrospective cohort studies and 9 case-control studies. The study included more than 86,000 participants. Analysis of postoperative complications revealed that the overall incidence of malnutrition-related complications after surgery was 3.17 times higher (OR = 3.17, 95% CI 2.69-3.75, z = 13.57, P < 0.05). The incidence of surgical site infections was 2.08 times higher (OR = 2.08, 95% CI 1.66-2.62, z = 6.307, P < 0.05), and the incidence of postoperative urinary tract infections was 2.55 times higher (OR = 2.55, 95% CI 1.80-3.60, z = 5.30, P < 0.05). The incidence of postoperative sepsis was 3.31 times higher (OR = 3.31, 95% CI 2.31-4.75, z = 6.51, P < 0.05), and the incidence of postoperative pneumonia was 3.02 times higher (OR = 3.02, 95% CI 1.331-6.857, z = 2.64, P = 0.008 < 0.05). The incidence of postoperative cardiac complications was 4.24 times higher (OR = 4.24, 95% CI 2.45-7.35, z = 5.15, P < 0.05), and the incidence of postoperative renal complications was 4.04 times higher (OR = 4.04, 95% CI 2.06-7.93, z = 4.05, P < 0.05). The incidence of postoperative pulmonary complications was 2.38 times higher (OR = 2.38, 95% CI 1.46-3.87, z = 6.98, P < 0.05), while the incidence of postoperative thrombotic complications was 2.76 times higher (OR = 2.76, 95% CI 1.756-4.345, z = 4.40, P < 0.05). Furthermore, the incidence of transfusion during and after surgery was 1.33 times higher (OR = 1.33, 95% CI 1.13-1.56, z = 3.40, P = 0.001 < 0.05), the incidence of postoperative readmission was 1.67 times higher (OR = 1.67, 95% CI 1.24-2.27, z = 3.33, P = 0.001 < 0.05), and the risk of postoperative death was 6.01 times higher (OR = 6.01, 95% CI 4.51-8.01, z = 12.27, P < 0.05). After conducting a publication bias test and Trim-and -Fill method analysis, we found no evidence of publication bias, and the results remained stable.

CONCLUSION

Preoperative low protein malnutrition is closely related to the incidence of postoperative complications and postoperative status. More prospective multicenter studies should be conducted to validate this conclusion. Furthermore, more effective assessment and intervention of preoperative nutritional status should be carried out to prevent the occurrence of postoperative complications and mortality risk.

Trends and Prediction of Surgical Site Infection After Elective Spine Surgery: An Analysis of the American College of Surgeons National Surgical Quality Improvement Project Database

Background: Surgical site infection (SSI) is an infrequent but costly complication after elective spine surgery. Identification of important temporal changes and predictive factors may inform targeted prevention efforts. Patients and Methods: A retrospective study of elective spine surgery patients was performed using the National Surgical Quality Improvement Programs (NSQIP) database from 2011 and 2019. Temporal changes in SSI and related factors were examined descriptively. Recursive partitioning and bootstrap forest techniques were used to inform the development of predictive models for SSI. Results: A total of 6,038 (1.66%) of 363,754 patients had an SSI recorded. Peri-operative transfusion and preoperative anemia decreased over the nine-year period, however, obesity and diabetes mellitus increased, whereas the SSI rate remained essentially unchanged. A full model including 15 variables had an area under the curve (AUC) of 0.693 (95% confidence interval [CI], 0.686-0.700) whereas a reduced model with just nine variables had an AUC of 0.690 (95% CI, 0.683-0.697). Adjusted odd ratios (aOR) greater than two were noted for only three variables; a posterior approach (aOR, 2.32; 95% CI, 2.14-2.50), body mass index (BMI) >40 kg/m² (aOR, 2.63; 95% CI, 2.39-2.90), and surgical duration longer than 350 minutes (aOR, 2.39; 95% CI, 2.14-2.67). Remaining retained variables included albumin <3.5 g/dL, inpatient procedure, peri-operative transfusion, diabetes mellitus (both insulin/non-insulin), anemia, and smoking. Conclusions: Surgical site infection rate remained unchanged over a nine-year period despite the lower rates of allogeneic blood transfusion. Class 3 obesity, long operative times, and a posterior approach mainly for thoracic/lumbar spine procedures seemed more pragmatic, but their predictive performance was only modest in our prediction models for SSI.

Postoperative 30-Day Comparative Complications of Multilevel Anterior Cervical Discectomy and Fusion and Laminoplasty for Cervical Spondylotic Myelopathy: An Evidence in Reaching Consensus

Although a few large-scale studies have investigated multilevel anterior cervical discectomy and fusion (ACDF) and laminoplasty (LAMP) and their related complications for cervical spondylotic myelopathy (CSM), the optimal surgical intervention remains controversial. Therefore, we compared their 30 days of postoperative complications. Through the 2010-2019 ACS NSQIP Participant Use Data Files, we estimated the risk of serious morbidity, reoperation, readmission, mortality, and other postoperative complications. Initially, propensity score matching (PSM) of the preoperative characteristics of both groups was performed for further analysis. Multivariable logistic regression analysis provided OR and 95% CI for comparative complications. After PSM, 621 pairs of cohorts were generated for both groups. Increased frequency of postoperative complications was observed in the LAMP group, especially for surgical wound infection, no matter whether superficial (ACDF/LAMP = 0%/1.13%, p = 0.0154) or deep wound infection (ACDF/LAMP = 0%/0.97%, p = 0.0309). The mean length of total hospital stays (ACDF/LAMP = 2.25/3.11, p < 0.0001) and days from operation to discharge (ACDF/LAMP = 2.12/3.08, p < 0.0001) were longer, while the hospitalization rate for over 30 days (ACDF/LAMP = 4.67%/7.41%, p = 0.0429) and unplanned reoperation (ACDF/LAMP = 6.12%/9.34%, p = 0.0336) were higher in LAMP. Results also indicated congestive heart failure as a risk factor (adjusted OR = 123.402, p = 0.0002). Conclusively, multilevel ACDF may be a safer surgical approach than LAMP for CSM in terms of perioperative morbidities, including surgical wound infection, prolonged hospitalization, and unplanned reoperation. However, these approaches showed no significant differences in systemic complications and perioperative mortality.

A nomogram to predict postoperative surgical site infection of adult patients who received orthopaedic surgery: a retrospective study

Surgical site infection is a common postoperative complication with serious consequences. This study developed a nomogram to estimate the probability of postoperative surgical site infection for orthopaedic patients. Adult patients following orthopaedic surgery during hospitalization were included in this study. We used univariate and multivariate logistic regression analyses to establish the predictive model, which was also visualized by nomogram. To evaluate the model performance, we applied the receiver operating characteristic curve, calibration curve, and decision curve analysis, which were utilized in external validation and internal validation. From January 2021 to June 2022, a total of 787 patients were enrolled in this study. After statistical analysis, five variables were enrolled in the predictive model, including age, operation time, diabetes, WBC, and HGB. The mathematical formula has been established as follows: Logit (SSI) = - 6.301 + 1.104 * (Age) + 0.669 * (Operation time) + 2.009 * (Diabetes) + 1.520 * (WBC) - 1.119 * (HGB). The receiver Operating Characteristic curve, calibration curve, and decision curve analysis presented a good performance of this predictive model. Our nomogram showed great discriminative ability, calibration, and clinical practicability in the training set, external validation, and internal validation.

Perioperative Nutritional Supplementation Decreases Wound Healing Complications Following Elective Lumbar Spine Surgery: A Randomized Controlled Trial

BACKGROUND

The prevalence of malnutrition in patients undergoing lumbar spine surgery ranges from 5% to 50% and is associated with higher rates of surgical site infections, medical complications, longer lengths of stay, and mortality.

PURPOSE

To determine if perioperative nutritional intervention decreases wound healing complications in patients undergoing lumbar spine surgery.

STUDY DESIGN/SETTING

A prospective randomized controlled trial.

MATERIALS AND METHODS

Patients aged 55+ undergoing elective primary lumbar surgery were included. Patients with a preoperative albumin<3.5 g/dL were defined as malnourished. Intervention group received nutritional supplementation (protein shake) twice daily from postoperative day 0 to two weeks postdischarge. Control group was instructed to continue regular daily diets. Primary outcomes included minor in-hospital complications (wound drainage, electrolyte abnormalities, hypotension, ileus, deep venous thrombus) and wound healing complications within 90 days. Secondary outcomes included 90-day emergency room visits, readmissions, and return to the operating room. Baseline data were compared between groups using means comparison tests. Multivariable analysis evaluated association of outcomes with nutritional supplementation. Subanalysis of malnourished patients assessed effects of nutritional supplementation on outcomes.

RESULTS

One hundred three patients were included. Thirty-seven (35.9%) were considered malnourished preoperatively. Forty-six (44.7%) received nutritional intervention and 57 (55.3%) served as controls. Adjusted analysis found patients receiving supplementation had lower rates of in-hospital minor complications (2.1% vs. 23.2%, P <0.01), and perioperative wound healing complications (3.4% vs. 17.9%, P <0.05). Subgroup analysis of 37 malnourished patients demonstrated that malnourished patients who received perioperative nutritional supplementation had lower rates of minor complications during admission (0.0% vs. 34.4%, P =0.01) and return to the operating room within 90 days (0.0% vs. 12.4%, P =0.04).

CONCLUSIONS

Over one third of patients undergoing lumbar surgery were malnourished. Nutritional supplementation during the two-week perioperative period decreased rates of minor complications during admission and wound complications within 90 days. Malnourished patients receiving supplementation less often returned to the operating room. To our knowledge, this is the first study to investigate the effects of perioperative nutritional intervention on wound healing complications for patients undergoing elective lumbar spine surgery.

LEVEL OF EVIDENCE

I.

Prophylactic Application of Vancomycin Powder in Preventing Surgical Site Infections After Spinal Surgery

OBJECTIVE

We sought to analyze the preventive effect of local vancomycin powder application on surgical site infection (SSI) in spinal surgeries and provide the basis for future clinical practice.

METHODS

Through PubMed, Medline, Elsevier, and the Cochrane Library, with MeSH words "vancomycin powder," "local/intraoperative/topical/intra-wound," "spine/spinal/lumbar/cervical/thoracolumbar," "surgery," "infection," and "SSI," we searched for case-control research papers on the impact of prophylactic application of vancomycin powder on the incidence of SSI and compared the rate of infection using RevMan 5.3 meta-analysis software.

RESULTS

A total of 1950 publications were found using the mesh words, and 50 of those studies were selected for final analysis. There were 34,301 cases in total, including 14,793 cases in vancomycin group and 19,508 cases in the control group. Results of meta-analysis showed that the incidence of SSI was significantly lower in the prophylactic vancomycin powder group than the control group (P < 0.001). Further subgroup analysis showed that the incidence of SSI was significantly lower in the prophylactic vancomycin powder group than the control group in spine surgeries with internal fixation, deformity correction, and deep tissue infections (P < 0.001). Meanwhile, there were no significant differences between the 2 groups concerning patients undergoing noninstrumented spine surgeries and the incidence of superficial tissue infection.

CONCLUSIONS

Overall, prophylactic application of vancomycin powder in spinal surgery can significantly reduce the incidence of SSI in deep tissues, and this effect is more prominent in patients undergoing internal fixation and deformity correction surgeries.

Investigating the Association of Patient Body Mass Index With Posterior Subcutaneous Fat Thickness in the Cervical Spine: A Retrospective Radiographic Study

INTRODUCTION

Although BMI is often used as a surrogate for posterior cervical subcutaneous fat thickness (SFT), the association of BMI with cervical SFT is unknown. We performed a retrospective radiographic study to analyze the relationship between BMI and cervical SFT.

METHODS

This was a retrospective cohort study of patients with cervical CT scans. SFT was assessed by measuring the distance (mm) from the spinous processes of C2-C7 to the skin edge. Pearson correlations and linear regression were used to analyze the relationship between BMI and SFT. One-way ANOVA was used to analyze differences in C2-C7 distances while stratifying by BMI.

RESULTS

A total of 96 patients were included. BMI had a moderate correlation with average C2-C7 (r=0.546, p < 0.05) SFT, and a weak to moderate correlation with each individual C2-C7 distance. The strongest correlation was at the C7 level (r= 0.583, p < 0.05). These analyses remained significant controlling for potential confounders of patient age, sex, and diabetes. No difference was found in the average C2-C7 distance in patients with BMIs of 25-30 compared to those with BMIs of 30-40 (p=0.996), whereas in patients with BMI <25 and BMI >40, differences were significant (p < 0.05).

CONCLUSIONS

BMI is not strongly correlated with SFT in the cervical spine. Although BMI less than 25 or greater than 40 is correlated with respectively decreased or increased cervical SFT, BMI of 25-40 is not correlated with cervical SFT. This is clinically important information for surgeons counseling patients on perioperative risk before undergoing cervical spine procedures, namely infection. Further research delineating the relationship between posterior SFT and surgical site infection in the cervical spine is warranted.

Incidence and local risk factors of infection after anterior sub-axial cervical spine surgery: retrospective database analysis of 4897 consecutive procedures

INTRODUCTION

The anterior cervical spine approach is safe and effective in many cervical spine pathologies. It is considered one of the most common approaches in spine surgery. Postoperative infections after anterior cervical surgery are rare but serious.

MATERIALS AND METHODS

This study is a retrospective database analysis. In this study, the incidence, and the local risk factors of postoperative infection after anterior-only sub-axial cervical spine surgery in a high-volume spine center were analyzed. The data of patients operated in a teaching hospital is electronically stored in a comprehensive medical database program. Postoperative infection after anterior cervical surgery from C2 to C7 was calculated and analyzed. In the study period, 4897 patients were operated. Twenty-four infections after a primary aseptic operation were detected. Independent local risk factors were estimated.

RESULTS

Postoperative infection occurred in 24/4897 patients (0.49%). The incidence of infection after cervical trauma was 3% (7/229), after spinal cord injury 4.3% (2/46), with myelopathy 1.98% (11/556), and after revision surgery 1.25% (7/560). The incidence showed a significant increase (p = 0.00, 0.01, 0.02). In 14 of the postoperatively infected patients (58.3%) an oesophageal injury was diagnosed. Odds ratios (OR) with a confidence interval (CI) of 95% was calculated. Independent risk factors for the postoperative infections were: Cervical trauma (OR 8.59, 95% CI 3.52-20.93), revision surgery (OR 3.22, 95% CI 1.33-7.82), The presence of cervical myelopathy (OR 6.71, 95% CI 2.99-15.06), and spinal cord injury (OR 9.33, 95% CI 2.13-40.83).

CONCLUSIONS

Postoperative infection after anterior cervical surgery is low (0.49%). In addition to the general risk factor for infection, the local risk factors are trauma, myelopathy, spinal cord injury, and revision surgeries. In the case of postoperative infection, an oesophageal injury should be excluded.

Association between hypoalbuminemia and complications after degenerative and deformity-correcting spinal surgeries: A systematic review and meta-analysis

Objective

The current review was designed to explore if hypoalbuminemia is associated with increased complications in patients undergoing spinal degenerative and deformities surgeries.

Methods

The search for eligible studies was conducted on the databases of PubMed, Embase, Web of Science, and CENTRAL up to 20th June 2022. Complication rates were pooled to obtain odds ratio (OR) and 95% confidence intervals.

Results

Thirteen studies were included. We found that hypoalbuminemia was significantly associated with increased risk of all complications (OR: 2.72 95% CI: 2.04, 3.63 I ²= 58% p < 0.00001), mortality (OR: 7.73 95% CI: 3.81, 15.72 I ²= 0% p < 0.00001), revision surgery (OR: 3.15 95% CI: 1.53, 6.48 I ²= 87% p = 0.002), readmissions (OR: 1.96 95% CI: 1.29, 2.98 I ²= 23% p = 0.02), surgical site infections (OR: 2.97 95% CI: 1.90, 4.63 I ²= 38% p < 0.00001), wound complications (OR: 2.31 95% CI: 1.17, 4.56 I ²= 48% p = 0.02), pulmonary complications (OR: 3.74 95% CI: 2.66, 5.26 I ²= 0% p < 0.00001), renal complications (OR: 3.04 95% CI: 1.22, 7.54 I ²= 0% p = 0.02), cardiac complications (OR: 4.33 95% CI: 2.14, 8.77 I ²= 0% p < 0.0001), urinary tract infections (OR: 2.08 95% CI: 1.80, 2.41 I ²= 0% p < 0.00001), and sepsis (OR: 4.95 95% CI: 1.87, 13.08 I ²= 64% p = 0.01) as compared to those with normal albumin.

Conclusion

Hypoalbuminemia is a significant risk factor for complications after spinal degenerative and deformity surgeries. Research is also needed on the role of nutritional support in improving outcomes after spinal degenerative and deformity surgeries.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42022340024.

Incidence and risk factors for surgical site infection (SSI) after primary hip hemiarthroplasty: an analysis of the ACS-NSQIP hip fracture procedure targeted database

INTRODUCTION

Primary hip hemiarthroplasty (HHA) is frequently utilized to treat geriatric hip fractures, which are associated with significantly higher morbidity and mortality. While not particularly common, surgical site infection (SSI) is a major complication that frequently requires revision surgery in a frail population. The objective of this study was to determine the incidence of and risk factors for SSI after HHA in hip fracture patients.

MATERIALS AND METHODS

This retrospective cohort study was performed using the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database. Geriatric patients (65+) who underwent HHA for non-pathologic, traumatic hip fractures between 2016-2017 were included. Demographic variables, comorbidities, operative variables, and complications were compared between "SSI" and "non-SSI" groups. Multivariate regression identified independent risk factors for postoperative SSI. Significance was set at P = 0.05.

RESULTS

A total of 6169 patients were included. The overall incidence of SSI was 1.3%. SSI was significantly associated with body mass index (BMI), preoperative functional status, congestive heart failure, chronic corticosteroid use, intraoperative time, sepsis, wound dehiscence, readmission within 30-days, and reoperation. On multivariate analysis, chronic steroid use (OR: 2.30, 95% CI: 1.13-4.70), BMI ≥ 35 kg/m² (OR: 3.59, 95% CI: 1.57-8.18), and intraoperative time ≥120 mins (OR: 2.15, 95% CI: 1.08-4.27) were found to be independent risk factors.

CONCLUSIONS

Postoperative SSI is a serious complication that is responsible for prolonged hospital stays, increased mortality, and greater healthcare costs. Here, we identified multiple risk factors for SSI after primary HHA in the US elderly population.

Incidence of complications associated with cervical spine surgery and post-operative physical therapy and implications for timing of initiation of post-operative physical therapy: a retrospective database study

PURPOSE

To describe the incidence of complications associated with cervical spine surgery and post-operative physical therapy (PT), and to identify if the timing of initiation of post-operative PT impacts the incidence rates.

METHODS

MOrtho PearlDiver database was queried using billing codes to identify patients who had undergone Anterior Cervical Discectomy and Fusion (ACDF), Posterior Cervical Fusion (PCF), or Cervical Foraminotomy and post-operative PT from 2010-2019. For each surgical procedure, patients were divided into three 12-week increments for post-operative PT (starting at post-operative weeks 2, 8, 12) and then matched based upon age, gender, and Charlson Comorbidity Index score. Each group was queried to determine complication rates and chi-square analysis with adjusted odds ratios, 95% confidence intervals, and p-values were used.

RESULTS

Following matching, 3,609 patients who underwent cervical spine surgery at one or more levels and had post-operative PT (ACDF:1784, PCF:1593, and cervical foraminotomy:232). The most frequent complications were new onset cervicalgia (2-14 weeks, 8-20 weeks, 12-24 weeks): ACDF (15.0%, 14.0%, 13.0%), PCF (18.8%, 18.0%, 19.9%), cervical foraminotomy (16.8%, 16.4%, 19.4%); revision: ADCF (7.9%, 8.2%, 7.4%), PCF (9.3%, 10.6%, 10.2%), cervical foraminotomy (11.6%, 10.8% and 13.4%); wound infection: ACDF (3.3%, 3.4%, 3.1%), PCF (8.3%, 8.0%,7.7%), cervical foraminotomy (5.2%, 6.5%, < 4.7%). None of the comparisons were statistically significant.

CONCLUSION

The most common post-operative complications included new onset cervicalgia, revision and wound infection. Complications rates were not impacted by the timing of initiation of PT whether at 2, 8, or 12 weeks post-operatively.

Minimally Invasive Instrumentation of the Cervical Spine: Past, Present, and Future

Posterior cervical instrumentation and fusion procedures are becoming more and more common with the aging population and rising numbers of multisegmental and revision procedures. The instrumentation of the cervical spine has so far been performed almost exclusively via open approaches. Over the past two decades, minimally invasive surgery (MIS) techniques have gained increasing popularity. To date, only a few attempts to instrument the cervical spine in a minimally invasive fashion have been reported. The following article, after a detailed review of the currently available literature, overviews MIS in dorsal cervical instrumentation and past, present and future techniques, and it discusses the current limitations. Nevertheless, and because of the multiple advantages of MIS instrumentation, a lot of work remains to be carried out to fully establish MIS procedures for posterior cervical instrumentation.

Predictors of 30-Day Readmission Following Cervical Laminoplasty in 3,085 Patients: An American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) Database Study

Background Cervical laminoplasty is a surgical alternative to laminectomy and fusion for treating multi-level cervical spondylotic myelopathy. There is limited evidence evaluating readmission incidence and risk factors following cervical laminoplasty. Here, we provide a retrospective review evaluating preoperative risk for 30-day readmission following cervical laminoplasty. Methodology The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was used to identify patients undergoing laminoplasty as defined by Current Procedural Terminology codes 63050 and 63051. Patients were then categorized based on whether 30-day readmission occurred, and preoperative risk factors were examined. Continuous and categorical variables were analyzed using Student's t-test or Fisher's exact test. Multivariate regression analysis was performed for each variable, with p-values of <0.05 considered significant. Results In total, 3,085 patients were identified as undergoing posterior cervical laminoplasty. Of these, 2,938 patients did not require readmission, and 147 patients were readmitted, representing a 4.77% 30-day readmission rate. For all patients, sepsis (odds ratio (OR) = 5.58, p = 0.03), dialysis (OR = 3.46, p = 0.01), American Society of Anesthesiologists class >2 (OR = 1.69, p = 0.011), and hypertension (OR = 1.51, p = 0.04) were predictive of readmission. A subgroup analysis was performed for all geriatric patients (aged >65). In total, 1,353 patients were identified, of whom 76 were readmitted, demonstrating a readmission rate of 5.62%. For the elderly patients, hypertension (OR = 1.98, confidence interval (CI) = 1.04-3.75, p = 0.04) and independent status (OR = 0.39, CI = 0.21-0.74, p = 0.004) were predictive of readmission. Conclusions Assessment of predictors for readmission is important for patient education and setting appropriate clinical expectations for surgeons and providers. Preoperative hypertension, dialysis, and sepsis were risk factors for 30-day readmission following cervical laminoplasty, with functional status being a unique risk factor for elderly patients.

Prospective Investigation of Surgical Outcomes after Anterior Decompression with Fusion and Laminoplasty for the Cervical Ossification of the Posterior Longitudinal Ligament: A Propensity Score Matching Analysis

The ideal surgical strategy for cervical ossification of the posterior longitudinal ligament (OPLL) remains controversial due to the lack of high-quality evidence. Herein, we prospectively investigated the surgical outcomes of anterior cervical decompression with fusion (ADF) and laminoplasty (LAMP) with cervical OPLL. Three hundred patients were included in this study (ADF: n = 89; LAMP: n = 211 patients), and propensity score matching yielded 67 pairs of patients with ADF and LAMP, in which clinical outcomes were compared. Crude analysis revealed that the ADF group showed greater neurological recovery in cervical Japanese Orthopedic Association scores at two years, compared with that in the LAMP group (53.1% vs. 44.3%, p = 0.037). The ratio of minimum clinically important difference (MCID) success was significantly greater in the ADF group (59.6% vs. 43.6%, p = 0.016). Multivariate analysis showed that the factors affecting MCID success were age, body mass index, duration of symptoms, and choice of ADF. In the 1:1 matched analysis, neurological improvement was more favorable in the ADF group (57.2%) compared to the LAMP group (46.8%) at two years (p = 0.049). However, perioperative complications, such as dysphagia and graft-related complications, were more common in the ADF group.

Large Surgical Databases with Direct Data Abstraction: VASQIP and ACS-NSQIP

Direct data abstraction from a patient's chart by experienced medical professional data abstractors has been the historical gold standard for quality and accuracy in clinical medical research. The limiting challenge to population-wide studies for quality and public health purposes is the high personnel costs associated with very large-scale efforts of this type. Two historically related programs that are at least partially able to successfully circumvent this problem and provide high-quality data relating to surgical procedures and the early postoperative period are reviewed in this article. Both utilize similar data abstraction efforts by specially trained and qualified medical abstractors of a sample subset of the total procedures performed at participating hospitals.The Veterans Affairs Surgical Quality Improvement Program (VASQIP), detailed by Nicholas J. Giori, MD, PhD, in the first section of this article, makes use of trained abstractors and has undergone recent additions and updates, including the development of an associated total hip registry for the VA system. The data elements and data integrity provided by both of these programs establish important benchmarks for other "big data" efforts, which often attempt to use alternative less-expensive methods of data collection in order to achieve more widespread or even nationwide data collection.In the second section, Elizabeth B. Habermann, PhD, MPH, provides a detailed review of the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP), the data elements collected, and examples of the range of quality improvement and outcomes studies in orthopaedic surgery that it has made possible, along with information on data that have not been collected and the resulting limitations. The ACS NSQIP was actually modeled after the very similar earlier effort started by the United States Department of Veterans Affairs (VA).

Interaction of basic diseases and low red blood cell count as critical murderer of wound infection after osteosarcoma resection: Wound infection after osteosarcoma resection

BACKGROUND

Surgical wound infection is one of the common complications in patients after osteosarcoma resection. It is imperative to grasp the risk factors comprehensively. Therefore, this study aimed to explore the risk factors of wound infection and deeply analyze the correlation between risk factors and wound infection.

METHODS

The study subjects were 101 patients who underwent osteosarcoma resection between April 2018 and August 2021. The diagnosis of postoperative wound infection was confirmed by postoperative observation of the incision, ultrasound imaging, and pathogenic examination. This study included a series of potential factors, mainly laboratory examination indicators and patients' general information. The statistical methods had Pearson Chi-square test, Spearman-rho correlation test, multifactorial linear regression model, logistic regression analysis, and receiver operating characteristic (ROC) curve.

RESULTS

Pearson Chi-square test and Spearman correlation test showed that red blood cell (RBC) count (P = .033) and basic diseases (P = .020) were significantly correlated with a surgical wound infection after osteosarcoma resection. Logistic regression analysis manifested that basic disease (OR = 0.121, 95% CI: 0.015-0.960, P = .046) and RBC (OR = 0.296, 95% CI: 0.093-0.944, P = .040) have a clear correlation with whether the patients have surgical wound infection after osteosarcoma resection. And the interaction of basic diseases and RBC could diagnose the surgical wound infection sensitively and accurately (AUC = 0.700, P = .014, 95% CI = 0.564-0.836) via the ROC analysis.

CONCLUSION

Patients with basic diseases and low RBC were risk factors for surgical wound infection after osteosarcoma resection.

A Risk Calculator for the Prediction of C5 Nerve Root Palsy After Instrumented Cervical Fusion

BACKGROUND

C5 palsy is a common postoperative complication after cervical fusion and is associated with increased health care costs and diminished quality of life. Accurate prediction of C5 palsy may allow for appropriate preoperative counseling and risk stratification. We primarily aim to develop an algorithm for the prediction of C5 palsy after instrumented cervical fusion and identify novel features for risk prediction. Additionally, we aim to build a risk calculator to provide the risk of C5 palsy.

METHODS

We identified adult patients who underwent instrumented cervical fusion at a tertiary care medical center between 2013 and 2020. The primary outcome was postoperative C5 palsy. We developed ensemble machine learning, standard machine learning, and logistic regression models predicting the risk of C5 palsy-assessing discrimination and calibration. Additionally, a web-based risk calculator was built with the best-performing model.

RESULTS

A total of 1024 patients were included, with 52 cases of C5 palsy. The ensemble model was well-calibrated and demonstrated excellent discrimination with an area under the receiver-operating characteristic curve of 0.773. The following features were the most important for ensemble model performance: diabetes mellitus, bipolar disorder, C5 or C4 level, surgical approach, preoperative non-motor neurologic symptoms, degenerative disease, number of fused levels, and age.

CONCLUSIONS

We report a risk calculator that generates patient-specific C5 palsy risk after instrumented cervical fusion. Individualized risk prediction for patients may facilitate improved preoperative patient counseling and risk stratification as well as potential intraoperative mitigating measures. This tool may also aid in addressing potentially modifiable risk factors such as diabetes and obesity.

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.

Cefazolin prophylaxis in spine surgery: patients are frequently underdosed and at increased risk for infection

BACKGROUND CONTEXT

Perioperative antibiotics are critical in reducing the risk of postoperative spine infections. However, the efficacy and optimal weight-based prophylactic cefazolin dosing is unclear.

PURPOSE

To determine (1) if inadequate weight-based prophylactic dosing of cefazolin affects infection rates after spinal fusions, and (2) identify the optimal dosing of cefazolin.

STUDY DESIGN/SETTING

Single center retrospective cohort PATIENT SAMPLE: Patients undergoing posterior cervical or lumbar spinal fusion between January 2000 and October 2020 OUTCOME MEASURES: Postoperative surgical site infection status METHODS: Patients were grouped based on our institutionally derived dosing adequacy standards, 1 g for <60 kg, 2 g for 60 to 120 kg, and 3 g for >120 kg. Univariate comparisons and multivariate regressions identified the effect of inadequate dosing on infection rate. Patients were subsequently regrouped into cefazolin dose (grams) administered and logistic regression and receiver operating characteristic curves were compiled to determine the probability of infection based on cefazolin dose and patient weight. Alpha was set at 0.05.

RESULTS

A total of 2,643 patients met inclusion criteria and 95 infections (3.6%) were identified. The infection rate was higher in the inadequate dosing group (5.86% vs. 2.58%, p<.001). Adequate dosing was a predictor of decreased infections after lumbar fusion (OR: 0.43, p<.001), but not posterior cervical fusions (OR: 0.47, p=.065). Patients were subsequently regrouped into 1 g or 2 g of cefazolin administered resulting in a 5.01% and 2.77% infection rate, respectively (p=.005). The area under the curve (AUC) and 95% confidence interval for one (0.850 [0.777-0.924]) and two (0.575 [0.493-0.657]) g of cefazolin demonstrated lower infection rates for patients given 2 g cefazolin.

CONCLUSIONS

Patients receiving an inadequate weight-based dose of preoperative cefazolin had an increased risk of infection following spinal fusion surgery. Two grams prophylactic cefazolin significantly reduces the likelihood of infection.

Off-label usage of RhBMP-2 in posterior cervical fusion is not associated with early increased complication rate and has similar clinical outcomes

BACKGROUND CONTEXT

Arthrodesis is important for the success of posterior cervical fusion (PCF), however, there exists limited data regarding the safety and efficacy of bone morphogenic protein (BMP) in PCF.

PURPOSE

The primary objective was to evaluate early postoperative complications associated with BMP in PCF and determine whether BMP leads to adverse early clinical outcomes. A secondary objective was to determine the optimal location for BMP sponge placement, within the facet joint (IF) or elsewhere, and the optimal dosage/level.

DESIGN

Retrospective, consecutive case-control study.

PATIENT SAMPLE

Seven hundred sixty-five patients who underwent PCF OUTCOME MEASURES: Patient-reported outcomes (PROs), complications, arthrodesis, optimum dose/level of BMP METHODS: Surgical data, including preoperative diagnosis, levels fused, type of bone graft, BMP dose (when used), and fusion technique were recorded. Complications were assessed by reviewing the medical record encompassing the first 6-weeks postoperative. These included medical, neurological, and wound-related complications and reoperation. Neurological complications were defined as any new weakness, radicular pain, or numbness. PROs were collected, including SF36, VAS, EQ-5D, and NDI scores. To determine the optimal dosage and location for BMP placement, a sub-analysis was performed.

RESULTS

There were no significant differences between the BMP and no BMP group with regards to wound complications, neurological complications, or reoperation. There were no differences in PROs between BMP and no BMP. Placement of BMP for IF and at a dose of 0.87 mg/level minimized wound-related complications. The BMP group had a higher fusion rate compared to the no BMP group (96% vs. 91%, p=.02) when assessed 1 year post-operatively.

CONCLUSION

BMP was not associated with a higher rate of early complications after PCF when the dose was minimized. Complications thought to be associated with BMP, such as compressive seroma, radiculitis, and wound-related complications were not seen at a higher rate. PROs at early follow-up were similar. Placement of BMP for IF and at lower doses than previously reported may minimize complications.

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.

30-day postoperative sepsis risk factors following laminectomy for intradural extramedullary tumors

BACKGROUND

Posterior laminectomy (LA) for resection of intradural extramedullary tumors (IDEMTs) is associated with postoperative complications, including sepsis. Sepsis is an uncommon but serious complication that can lead to increased morbidity and mortality, prolonged hospital stays, and greater costs. Given the susceptibility of a solid tumor patients to sepsis-related complications, it is important to recognize IDEMT patients as a unique population when assessing the risk factors for sepsis after laminectomy.

METHODS

The study design was a retrospective cohort study. Adult patients undergoing LA for IDEMTs from 2012 to 2018 were identified in the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database. Baseline patient characteristics/comorbidities, operative and hospital variables, and 30-day postoperative complications were collected.

RESULTS

Of 2,027 total patients undergoing LA for IDEMTs, 38 (2%) had postoperative sepsis. On bivariate analysis sepsis was associated with superficial surgical site infection [odds ratio (OR) 11.62, P<0.001], deep surgical site infection (OR 10.67, P<0.001), deep vein thrombosis (OR 10.75, P<0.001), pulmonary embolism (OR 15.27, P<0.001), transfusion (OR 6.18, P<0.001), length of stay greater than five days (OR 5.41, P<0.001), and return to the operating room within thirty days (OR 8.72, P<0.001). Subsequent multivariate analysis identified the following independent risk factors for sepsis and septic shock: operative time ≥50th percentile (OR 2.11, P=0.032), higher anesthesia class (OR 1.76, P=0.046), dependent functional status (OR 2.23, P=0.001), diabetes (OR 2.31, P=0.037), and chronic obstructive pulmonary disease (OR 3.56, P=0.037).

CONCLUSIONS

These findings can help spine surgeons identify high-risk patients and proactively deploy measures to avoid this potentially devastating complication in individuals who may be more vulnerable than the general elective spine population.

Increased risk of postoperative wound complications among obesity classes II & III after ALIF in 10-year ACS-NSQIP analysis of 10,934 cases

BACKGROUND CONTEXT

Anterior lumbar interbody fusion (ALIF) procedures for lumbar spine disease have been increasing amid a growing obese patient population with limited studies available focusing exclusively on risk-factors for post-operative ALIF complications.

PURPOSE

The objective of this study was to compare 30-day post-operative complications among different obesity World Health Organization classes according to body mass index (BMI) in comparison to non-obese patients who underwent an ALIF procedure.

STUDY DESIGN/SETTING

Retrospective cohort study of the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) from 2009 to 2019.

PATIENT SAMPLE

A total of 10,934 patients undergoing an ALIF.

OUTCOME MEASURES

Primary outcome measures include 30 day cardiac, pulmonary, urinary, infectious, and wound complications. Secondary outcomes included rates of blood transfusion, reintubation, deep vein thrombosis, pulmonary embolism, 30-day return to the operating room (OR), and 30 day mortality.

METHODS

Patients were identified by use of the current procedural terminology codes 22558 and 22585 from 2009 to 2019. Patients were divided into the following groups: non-obese (BMI 18.5-29.9 kg/m²), Obese I (BMI 30-34.9 kg/m²), Obese II (BMI 35-39.9 kg/m²), and Obese III (BMI ≥40 kg/m²). Age, gender, race, American Society of Anesthesiologists status, smoking status, hypertension requiring medication, steroid used, chronic obstructive pulmonary disease, history of a bleeding disorder, and diabetes was identified as risk factors after a univariate analysis conducted for demographic variables and pre-operative comorbidities. A multivariate logistic regression analysis was then performed to adjust for these preoperative risk factors and compare obesity classes I-III to non-obese patients.

RESULTS

Obesity classes II and III had a significant odds ratio (OR) for superficial infection (OR:2.7, 95%CI(1.7-4.5); OR:2.8, 95%CI(1.5-5.2) respectively), organ space infection (OR:3.8, 95%CI(1.6-7.4); OR:3.2, 95%CI(1.1-9.9) respectively), wound disruption (OR:2.8, 95%CI(1.1-7.4); OR:4.6, 95%CI(1.6-13.6) respectively), and total wound complication (OR:2.6, 95%CI(1.8-3.9); OR:3.4, 95%CI(2.2-5.4) respectively) following a multivariate logistic regression analysis.

CONCLUSIONS

Risk for post-operative wound complications following an ALIF were found to be significantly higher for obesity classes II-III in comparison to non-obese patients. These findings can further support the use of additional wound care in the perioperative setting for certain levels of obesity.

Drains in Spine Surgery for Degenerative Disc Diseases: A Literature Review to Determine Its Usage

No guidelines currently exist for surgeons to follow regarding drain use after spine surgery for degenerative disc disease. Therefore, we conducted a literature review to determine what situations warrant drain placement versus those which do not. When placed, we further investigate optimal drain duration. The goal of this article is to provide spine surgeons insight into the current literature and guidance when deciding if a drain should be used or discontinued. We performed a PubMed search and analyzed 44peer-reviewed journal articles. Only studies that had the full article available were included. The highest-quality studies that were reviewed, demonstrated that in most situations using a drain is not associated with superior outcomes. It revealed that when drains are retained for a longer duration they run a greater risk of surgical site infection (SSI). Additionally, drains are associated with increased blood loss, a greater chance of requiring blood transfusions, and longer hospital stays. We conclude that drains are currently being overused in spine surgery for cases of degenerative disc disease, which exposes patients to unnecessary complications while providing minimal benefit.

Increased Surgical Site Subcutaneous Fat Thickness Is Associated with Infection after Posterior Cervical Fusion

Background: Previous literature has associated increased body mass index (BMI) with risk of surgical site infection (SSI) after posterior cervical fusion (PCF) surgery. However, few studies have examined the association between local adiposity and risk of SSI, re-admission, and re-operation after PCF. Local adiposity is easily measured on pre-operative magnetic resonance imaging (MRI) and may act as a more accurate predictor compared with BMI. Patients and Methods: Subjects undergoing PCF from 2013-2018 at a single institution were identified retrospectively. Posterior cervical subcutaneous fat thickness, paraspinal muscle thickness, and lamina-to-skin distance measurements were obtained from computed tomography (CT) or MRI scans. Subjects with active infection, malignancy, or revision procedures were excluded. Results: Two hundred five patients were included with 20 developing SSIs. Subjects with SSIs had a longer fusion construct (4.90 vs. 3.71 levels; p = 0.001), higher Elixhauser comorbidity index (ECI; 2.05 vs. 1.34; p = 0.045), had a history of diabetes mellitus (30% vs. 10.8%; p = 0.026), higher subcutaneous fat thickness (30.5 vs. 23.6 mm; p = 0.013), and higher lamina-to-skin distance (66.4 vs. 57.9 mm; p = 0.027). Subcutaneous fat thickness (odds ratio [OR], 1.05; 95% confidence interval [CI], 1.01-1.10]; p = 0.026) and lamina-to-skin distance (OR, 1.05; 95% CI, 1.01-1.09]; p = 0.014) were associated with SSI in multivariable analysis. A subcutaneous fat thickness cutoff value of 23.2 mm had 90% sensitivity and 54.1% specificity for prediction of SSI. There was no association need for re-admission or re-operation. Conclusions: Increased posterior cervical fat may increase the risk of SSI after PCF. Pre-operative advanced imaging may be a valuable tool for assisting with patient counseling, optimization, and risk stratification.

Anterior vs Posterior Approach in Multilevel Cervical Spondylotic Myelopathy: A Nationwide Propensity-Matched Analysis of Complications, Outcomes, and Narcotic Use

BACKGROUND

There is unclear evidence regarding the optimal surgical approach for multilevel cervical spondylotic myelopathy (CSM). The objective of this study was to compare complications, outcomes, and narcotic use in anterior discectomy and fusion (ACDF) vs posterior decompression and fusion (PCDF) in CSM patients.

STUDY DESIGN

Registry-based retrospective cohort analysis.

METHODS

Patients undergoing 3-level ACDF or PCDF for CSM between 2007 and 2017 were identified from the Humana Claims Database using relevant procedure codes. Propensity score-matched groups were compared in regards to complications, outcomes, and narcotic use.

RESULTS

Propensity score matching generated equal cohorts of 6124 patients. The posterior fusion group had a higher rate of urinary tract infection (OR 2.47, P < 0.0001), deep vein thrombosis (OR 1.90, P < 0.0001), and pulmonary embolism (OR 1.75, P < 0.0001). In regards to 30-day outcomes, the posterior approach demonstrated higher rates of stroke (OR 1.68, P < 0.0001), wound dehiscence (OR 5.59, P < 0.0001), Surgical site infection (SSI) (OR 4.76, P < 0.0001), wound revision surgery (OR 3.02, P < 0.0001), and all-cause readmission (OR 2.01, P < 0.0001). One-year outcomes revealed higher rates of pseudarthrosis (4.7% vs 2.0%, OR 2.43, P < 0.0001) and revision or extension surgery (OR 2.33, P < 0.0001) in the posterior fusion cohort. These patients also demonstrated significantly higher mean morphine milligram equivalent used at 30 days (OR 1.19, P < 0.0001), as well as 60 (OR 1.20, P < 0.0001), 90 (OR 1.21, P < 0.0001), and 120 (OR 1.21, P < 0.0001) days.

CONCLUSIONS

This nationwide propensity-matched analysis of multilevel CSM patients found the posterior approach to be associated with increased rates of inpatient complications, wound complications, 30-day readmission, 1-year pseudarthrosis, and 1-year revision or extension surgery. These patients also demonstrated higher levels of narcotic use up to 120 days after surgery.

CLINICAL RELEVANCE

The posterior approach for treatment of CSM may be associated with increased rates of short- and long-term complications in addition to increased narcotic consumption in comparison to the anterior approach.

Severe complication subsequent to surgical site infection after cervical laminoplasty: a case report

INTRODUCTION

Surgical site infections (SSI) following spinal surgery can result in serious complications. Although early detection and intensive care are essential to minimize possible sequelae, more than one surgical intervention is required to alleviate the infection in some cases.

CASE PRESENTATION

A 66-year-old man with long-standing Parkinson's disease (PD) developed SSIs after cervical laminoplasty. Despite surgical debridement and irrigation, his neurological status worsened severely and anterior infectious involvement at the C4-5 level was identified by magnetic resonance imaging. He underwent another urgent surgery for anterior debridement and iliac bone grafting. His laboratory results gradually normalized with antibiotic therapy, and his neurological status improved. One year after surgery, he was ambulatory with walker assistance. However, his right hand remained difficult to control with significant sensory loss and numbness.

DISCUSSION

To our knowledge, this is the first case of SSI that extended rapidly to the anterior side despite immediate and intensive treatment in a patient with PD after laminoplasty. During SSI treatment, meticulous observation should be performed to check for exacerbations.

Development and Internal Validation of Supervised Machine Learning Algorithms for Predicting the Risk of Surgical Site Infection Following Minimally Invasive Transforaminal Lumbar Interbody Fusion

Purpose: Machine Learning (ML) is rapidly growing in capability and is increasingly applied to model outcomes and complications in medicine. Surgical site infections (SSI) are a common post-operative complication in spinal surgery. This study aimed to develop and validate supervised ML algorithms for predicting the risk of SSI following minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF).

Methods: This single-central retrospective study included a total of 705 cases between May 2012 and October 2019. Data of patients who underwent MIS-TLIF was extracted by the electronic medical record system. The patient's clinical characteristics, surgery-related parameters, and routine laboratory tests were collected. Stepwise logistic regression analyses were used to screen and identify potential predictors for SSI. Then, these factors were imported into six ML algorithms, including k-Nearest Neighbor (KNN), Decision Tree (DT), Support Vector Machine (SVM), Random Forest (RF), Multi-Layer Perceptron (MLP), and Naïve Bayes (NB), to develop a prediction model for predicting the risk of SSI following MIS-TLIF under Quadrant channel. During the training process, 10-fold cross-validation was used for validation. Indices like the area under the receiver operating characteristic (AUC), sensitivity, specificity, and accuracy (ACC) were reported to test the performance of ML models.

Results: Among the 705 patients, SSI occurred in 33 patients (4.68%). The stepwise logistic regression analyses showed that pre-operative glycated hemoglobin A1c (HbA1c), estimated blood loss (EBL), pre-operative albumin, body mass index (BMI), and age were potential predictors of SSI. In predicting SSI, six ML models posted an average AUC of 0.60–0.80 and an ACC of 0.80–0.95, with the NB model standing out, registering an average AUC and an ACC of 0.78 and 0.90. Then, the feature importance of the NB model was reported.

Conclusions: ML algorithms are impressive tools in clinical decision-making, which can achieve satisfactory prediction of SSI with the NB model performing the best. The NB model may help access the risk of SSI following MIS-TLIF and facilitate clinical decision-making. However, future external validation is needed.

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.

Minimizing transrectal prostate biopsy-related infections; A prospective randomized trial of povidone-iodine intrarectal cleaning versus formalin needle disinfection

Introduction:

Transrectal prostate biopsies are associated with post biopsy infection and sepsis. We compared the efficacy of povidone-iodine rectal disinfection versus formalin needle disinfection in preventing post biopsy infection among patients undergoing transrectal ultrasound-guided prostate biopsy.

Methods:

Patients scheduled to undergo ultrasound-guided transrectal prostate biopsy (n = 621) over 20 months were randomized into 2 groups to receive either povidone-iodine intrarectal disinfection or formalin disinfection of needle after each core. These were compared to assess which methodology better prevented postprocedure infection. Statistical analysis were used to identify independent factors promoting infections.

Results:

Two hundred and ninety-eight patients from povidone-iodine intrarectal disinfection were compared with 300 from formalin needle disinfection group. Formalin needle disinfection was associated with significantly more infections (P = 0.02). Escherichia coli was the dominant pathogen, with >50% of cases being quinolone resistant. Type of disinfection (P = 0.002), BMI (P = 0.001), chronic prostatitis (P = 0.002), and diabetes mellitus (P = 0.01) were independent predictors of infections. BMI at 28.95 kg/m² provided the best predictive cut-off point for infections, irrespective of method of disinfection. Area under the curve for all these parameters together was 0.91.

Conclusions:

We conclude that along with oral cephalosporin prophylaxis, povidone-iodine intrarectal disinfection is a superior to formalin needle disinfection alone in preventing post biopsy infection. Patients with BMI >28.95 kg/m² should be considered at a higher risk for infections.

Sexual dimorphism of the posterior cervical spine muscle attachments

Cervical spinal injury and neck pain are common disorders with wide physical implications. Neck pain and disability are reported to occur in females more often than in males, and chronic or persistent neck pain after whiplash is twice as common in females. Female athletes also sustain a higher percentage of concussions compared to male athletes. Still, while sexual differences in clinical presentation and outcome are well-established, the underlying etiology for the disparity remains less clear. It is well-established that the origin and insertion landmarks of posterior neck muscles are highly variable, but we do not know if these interindividual differences are associated with sex. Expanding our knowledge on sexual dimorphism in the anatomy of the cervical muscles is essential to our understanding of the possible biomechanical differences between the sexes and hence improves our understanding as to why females suffer from cervical pain more than males. It is also of paramount importance for accurate planning of posterior cervical spine surgery, which cuts through the posterior cervical musculature. Therefore, our main objective is to characterize the anatomy of posterior neck musculature and to explore possible sexual differences in the location of their attachment points. Meticulous posterior neck dissection was performed on 35 cadavers, 19 females, and 16 males. In each specimen, 8 muscle groups were examined bilaterally at 45 osseous anatomical landmarks. Muscles and their attachment sites were evaluated manually then photographed and recorded using Microscribe Digitizer technology built into 3D models. A comparison of attachment landmarks between males and females for each muscle was conducted. Out of the eight muscles that were measured, only two muscles demonstrated significant sex-related anatomical differences-Spinotranversales (splenius capitis and cervicis) and Multifidus. Male Spinotransversales muscle has more attachment points than female. It showed more cranial insertion points in the upper cervical attachments (superior nuchal line, C1 posterior tubercle, and mastoid process) and more caudal insertion points in the spinous processes and transverse processes of the lower cervical and upper thoracic vertebrae. Thus, the male subjects in this study exhibited a greater coverage of the posterior neck both cranially and caudally. Female Multifidus has more attachment points on the spinous processes and articular processes at middle and lower cervical vertebrae and at the transverse processes of the upper thoracic vertebrae. All remaining muscles exhibited no sexual differences. Our findings highlight, for the first time, a sexual dimorphism in attachment points of posterior cervical musculature. It reinforces the notion that the female neck is not a scaled version of the male neck. These differences in muscle attachment could partially explain differences in muscle torque production and range of motion and thus biomechanical differences in cervical spine stabilization between sexes. It sheds a much-needed light on the reason for higher whiplash rates, concussion, and chronic cervical pain among females. Surgeons should take these sexual morphological differences into consideration when deliberating the best surgical approach for posterior cervical surgery.

A Web-Based Calculator for Predicting the Occurrence of Wound Complications, Wound Infection, and Unplanned Reoperation for Wound Complications in Patients Undergoing Surgery for Spinal Metastases

BACKGROUND

In the present study, we identified the risk factors for wound complications, wound infection, and reoperation for wound complications after spine metastasis surgery and deployed the resultant model as a web-based calculator.

METHODS

Patients treated at a single comprehensive cancer center during a 7-year period were included. The demographics, pathology, comorbidities, laboratory values, and operative details were collected. Factors with P < 0.15 on univariable regression were entered into multivariable logistic regression to generate predictive models internally validated using 1000 bootstrapped samples.

RESULTS

Of the 330 patients included, 29 (7.6%) had experienced a surgical site infection. The independent predictive factors for wound-related complications were a higher Charlson comorbidity index (CCI; odds ratio [OR], 1.41 per point; P < 0.01), Karnofsky performance scale score ≤70 (OR, 2.14; P = 0.04), lower platelet count (OR, 0.49 per 10⁵/μL; P < 0.01), revision versus index surgery (OR, 3.10; P = 0.02), and increased incision length (OR, 1.21 per level; P = 0.02). Wound infection was associated with a higher CCI (OR, 1.60 per point; P < 0.01), a lower platelet count (OR, 0.35 per 10⁵/μL; P < 0.01), revision surgery (OR, 4.63; P = 0.01), and a longer incision length (OR, 1.25 per level; P = 0.03). Unplanned reoperation for wound complications was predicted by a higher CCI (OR, 1.39 per point; P = 0.003), prior irradiation (OR, 2.52; P = 0.04), a lower platelet count (OR, 0.57 per 10⁵/μL; P = 0.02), and revision surgery (OR, 3.34; P = 0.03), The optimism-corrected areas under the curve were 0.75, 0.81, and 0.72 for the wound complication, infection, and reoperation models, respectively.

CONCLUSIONS

Low platelet counts, poorer health status, more invasive surgery, and revision surgery all independently predicted the risk of wound complications, including infection and unplanned reoperation for infection. Validation of the calculators in a prospective study is merited.

Review of Pre-Operative Skin Preparation Options Based on Surgical Site in Orthopedic Surgery

Background: Surgical site infections (SSIs) are a primary contributor to surgical morbidity and mortality, causing a substantial financial burden on the healthcare system. Specifically, Cutibacterium acnes contributes greatly to infections in the shoulder and spine regions. Prevention of infection is crucial to improve patient outcomes and reduce costs. This article reviews current surgical skin preparation solutions, the unique distribution of organisms at common orthopedic surgical sites, and recommends solutions based on surgical location. Methods: A search of electronic databases (PubMed, MEDLINE, and Embase) was conducted for relevant literature until December 2020. Sources were compiled based on title and abstract, then full texts were read for possible inclusion. This review summarizes the most recent publications in the field of SSIs and preparation solutions. Results: The mechanism and efficacy of alcohol-, iodine-, and chlorhexidine-based preparations were reviewed, along with experimental preparations. This article identifies common colonization patterns for the shoulder, elbow, hip, knee, spine, foot, and ankle, and discusses recommendations for preparations based on current evidence. Recommendations: For shoulder and elbow operations, we recommend ChloraPrep™ (CareFusion, BD, El Paso, TX), DuraPrep™ (3M Health Care, St. Paul, MN), or Betadine^® applied with 4 × 4 gauze sponge, three-day pre-operative benzyl peroxide, and application of 3% hydrogen peroxide before skin preparation. For the hip and knee, we recommend application of 2% chlorhexidine gluconate (CHG) cloth the night before and morning of surgery and either DuraPrep or iodine-alcohol skin prep prior to surgery. For spine surgeries, we recommended ChloraPrep. For foot and ankle, our recommendations are: ChloraPrep or DuraPrep, submersion of foot in 70% ethanol/10% isopropyl alcohol for five minutes prior to procedure, application with a bristled brush, and a second vigorous scrub with 4 × 4 soaked gauze. Conclusions: The current surgical skin preparations have both benefits and drawbacks. We recommend that orthopedic surgeons choose a skin preparation based on surgical site and prevalence of unique skin flora there.

Comparison of Perioperative Complications in Anterior Decompression With Fusion and Posterior Decompression With Fusion for Cervical Spondylotic Myelopathy: Propensity Score Matching Analysis Using a Nationwide Inpatient Database

STUDY DESIGN

A retrospective cohort study with a national inpatient database.

OBJECTIVE

This study aimed to research the perioperative complication rates of cervical spondylotic myelopathy (CSM) patients who underwent anterior decompression with fusion (ADF) and posterior decompression with fusion (PDF) using a large national inpatient database and propensity score matching (PSM) analysis.

SUMMARY OF BACKGROUND DATA

There are several ways to successfully achieve surgical spinal decompression in CSM patients; however, evidence of the systemic complications and reoperation rates in ADF and PDF is lacking.

MATERIALS AND METHODS

We identified patients who were hospitalized for CSM and underwent either ADF or PDF from 2010 to 2016 using the Japanese Diagnosis Procedure Combination database. In the ADF and PDF groups, we compared postoperative complications (systemic and local), medical costs during hospitalization, and mortality before and after PSM. In addition, multivariate regression analysis was performed to identify risk factors for perioperative systemic complications.

RESULTS

A total of 1013 matched pairs were made after PSM. More perioperative systemic complications were detected in the ADF group than in the PDF group (at least 1 complication: ADF vs. PDF: 15.2% vs. 12.0%, P=0.038), especially for respiratory failure (1.4% vs. 0.4%, P=0.018), pneumonia (1.9% vs. 0.5%, P=0.004), and dysphagia (3.0% vs. 1.1%, P=0.003). The costs were ~$8000 higher (P<0.001) and the length of hospital stay was almost 5 days longer (P<0.001) in the PDF group. The risk factors for perioperative systemic complications in ADF were high age, low body mass index, and preoperative respiratory disease, and the factors in PDF were high body mass index and preoperative renal disease.

CONCLUSION

More systemic complications, especially respiratory events, were more frequently observed in the ADF group, while the medical costs were higher and the hospital stay was longer in the PDF group.

LEVEL OF EVIDENCE

Level III.

Accuracy of hospital-based surveillance systems for surgical site infection after adult spine surgery: A Bayesian latent class analysis

BACKGROUND

Surgical site infections (SSIs) of the spine are morbid and costly complications. An accurate surveillance system is required to properly describe the disease burden and the impact of interventions that mitigate SSI risk. Unfortunately, uniform approaches to conducting SSI surveillance are lacking because of varying SSI case definitions, the lack of a perfect reference case definition and heterogeneous data sources.

AIM

We assessed the accuracy of 4 independent data sources that capture SSIs after spine surgery, with estimation of a measurement error-adjusted SSI incidence.

METHODS

A Bayesian latent class model assessed the sensitivity/specificity of each data source to identify SSI and to estimate a measurement-error adjusted incidence. The four data sources used were: the discharge abstract database (DAD), the National Surgical Quality Improvement Program (NSQIP) database, the Infection Prevention and Control Canada (IPAC) database, and the Spine Adverse Events Severity database.

FINDINGS

A total of 904 patients underwent spine surgery in 2017. The most sensitive data source was DAD (0.799, 95% CrI 0.597, 0.943), while the least sensitive was NSQIP (0.497, 95% CrI 0.308, 0.694). The most specific data source was IPAC (0.997, 95% CrI 0.993, 1.000) and the least specific was DAD (0.969, 95% CrI 0.956, 0.981). The measurement error-adjusted SSI incidence was 0.030 (95% CrI 0.019, 0.045). The crude incidence using the DAD over-estimated the incidence, and the 3 other data sources under-estimated it.

CONCLUSION

SSI surveillance in the spine surgery population is feasible using several data sources, provided that measurement error is considered.

Antimicrobial prophylaxis in noninstrumented spine surgery: a prospective study to determine efficacy and drawbacks

OBJECTIVE

The authors sought to evaluate the roles of perioperative antibiotic prophylaxis in noninstrumented spine surgery (NISS), both in postoperative infections and the impact on the selection of resistant bacteria. To the authors' knowledge, only one prospective study recommending preoperative intravenous (IV) antibiotics for prophylaxis has been published previously.

METHODS

Two successive prospective IV antibiotic prophylaxis protocols were used: from 2011 to 2013 (group A: no prophylactic antibiotic) and from 2014 to 2016 (group B: prophylactic cefazolin). Patient infection rates, infection risk factors, and bacteriological status were determined.

RESULTS

In total, 2250 patients (1031 in group A and 1219 in group B) were followed for at least 1 year. The authors identified 72 surgical site infections, 51 in group A (4.9%) and 21 in group B (1.7%) (p < 0.0001). A multiple logistic regression hazard model identified male sex (HR 2.028, 95% CI 1.173-3.509; p = 0.011), cervical laminectomy (HR 2.078, 95% CI 1.147-3.762; p = 0.016), and postoperative CSF leak (HR 43.782, 95% CI 10.9-189.9; p < 0.0001) as independent predictive risk factors of infection. In addition, preoperative antibiotic prophylaxis was the only independent favorable factor (HR 0.283, 95% CI 0.164-0.488; p < 0.0001) that significantly reduced infections for NISS. Of 97 bacterial infections, cefazolin-resistant bacteria were identified in 26 (26.8%), with significantly more in group B (40%) than in group A (20.9%) (p = 0.02).

CONCLUSIONS

A single dose of preoperative cefazolin is effective and mandatory in preventing surgical site infections in NISS. Single-dose antibiotic prophylaxis has an immediate impact on cutaneous flora by increasing cefazolin-resistant bacteria.

Postoperative Glycemic Variability and Adverse Outcomes After Posterior Cervical Fusion

INTRODUCTION

Posterior cervical decompression and fusion (PCDF) is a procedure commonly performed to help alleviate symptoms and improve quality of life in patients experiencing cervical spondylotic myelopathy, multilevel stenosis, and cervical deformity. Although various risk factors have been linked to adverse outcomes in patients after PCDF, this is the first study that specifically explores postoperative glycemic variability and its association with adverse outcomes.

METHODS

A retrospective cohort study was conducted with a total of 264 patients after PCDF procedures that had available postoperative blood glucose measurements. Patients were divided into tertiles based on their coefficient of variation as an indicator of glycemic variability. Outcomes measured included inpatient complications, length of stay (LOS), 90-day readmission, revision, and surgical site infection rates.

RESULTS

Results showed a significant difference in glycemic variability among tertiles with respect to LOS (P = 0.01). The average LOS for the first, second, and third tertiles was 3.90 (3.20, 4.59), 5.73 (4.45, 7.00), and 6.06 (4.89, 7.22), respectively. Logistic regression analysis showed significantly higher odds of readmission (odds ratio: 4.77; P = 0.03) and surgical site infections (odds ratio: 4.35; P = 0.04) in the high glycemic variability group compared with the low glycemic variability group within 90 days of surgery. No significant difference was noted among tertiles with respect to inpatient complications.

DISCUSSION

This study establishes a relationship between postoperative glycemic variability and LOS, as well as 90-day readmission and surgical site infection rates after PCDF. Our results suggest that limiting fluctuations in blood glucose levels may curtail inpatient healthcare costs related to in-hospital stay. Although immediate postoperative glycemic variability is ultimately acceptable, before discharge, proper glucose management plans should be in place to help prevent adverse patient outcomes.

The influence of modifiable risk factors on short-term postoperative outcomes following cervical spine surgery: A retrospective propensity score matched analysis

BACKGROUND

Modifiable risk factors (MRFs) represent patient variables associated with increased complication rates that may be prevented. There exists a paucity of studies that comprehensively analyze MRF subgroups and their independent association with postoperative complications in patients undergoing cervical spine surgery. Therefore, the purpose of this study is to compare outcomes between patients receiving cervical spine surgery with reported MRFs.

METHODS

Retrospective analysis of the Nationwide Readmissions Database (NRD) from the years 2016 and 2017, a publicly available and purchasable data source, to include adult patients undergoing cervical fusion. MRF cohorts were separated into three categories: substance abuse (alcohol, tobacco/nicotine, opioid abuse); vascular disease (hypertension, dyslipidemia); and dietary factors (malnutrition, obesity). Three-way nearest-neighbor propensity score matching for demographics, hospital, and surgical characteristics was implemented.

FINDINGS

We identified 9601 with dietary MRFs (D-MRF), 9654 with substance abuse MRFs (SA-MRF), and 9503 with vascular MRFs (V-MRF). Those with d-MRFs had significantly higher rates of medical complications (9.3%), surgical complications (8.1%), and higher adjusted hospital costs compared to patients with SA-MRFs and V-MRFs. Patients with d-MRFs (16.3%) and V-MRFs (14.0%) were independently non-routinely discharged at a significantly higher rate compared to patients with SA-MRFs (12.6%) (p<0.0001 and p = 0.0037). However, those with substance abuse had the highest readmission rate and were more commonly readmitted for delayed procedure-related infections.

INTERPRETATION

A large proportion of patients who receive cervical spine surgery have potential MRFs that uniquely influence their postoperative outcomes. A thorough understanding of patient-specific MRF subgroups allows for improved preoperative risk stratification, tailored patient counseling, and postoperative management planning.

FUNDING

None.

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.