Risk Modeling Predicts Complication Rates for Spinal Surgery

Retrospective Single-Center Analysis of 5575 Spinal Surgeries for Complication Associations and Potential Future Use of Generated Data

Background: This study aims to retrospectively detect associations with postoperative complications in spinal surgeries during the hospitalization period using standardized, single-center data to validate a method for complication detection and discuss the potential future use of generated data. Methods: Data were generated in 2006-2019 from a standardized, weekly complications conference reviewing all neurosurgical operations at the University Hospital Luebeck. Paper-based data were recorded in a standardized manner during the conference and transferred with a time delay of one week into a proprietary complication register. A total of 5575 cases were grouped based on the diagnosis, surgical localization, approach, instrumentation, previous operations, surgery indication, age, ASA score, and pre-existing conditions. Retrospective analysis was performed using a logistic regression detecting complication associations. The results were compared to the literature validating the method of complication detection. Results: Mean cohort age: 58.83 years. Overall complication rate: 10.9%. Mortality rate: 0.25%. The statistically significant complication associations were age; an age of >60; the localization (cervical, thoracic); a cervical tumor or trauma diagnosis; lumbar degenerative conditions, tumor, trauma, or infection; a cervical hemi-/laminectomy and vertebral body replacement; a lumbar hemi-/laminectomy, posterior spondylodesis, and 360° fusion; lumbar instrumentation, with an ASA score of three and four; a ventral and combined/360° approach; a lumbar combined/360° revision; two, three and ≥four pre-existing conditions; hypertension; osteoporosis; arrhythmia; an oncological condition; kidney dysfunction; stroke; and thrombosis. Conclusions: Documenting risk profiles for spinal procedures is important in identifying postoperative complications. The available data provide a comprehensive overview within a single center for spinal surgeries. Standardized complication recording during an established complication conference in the clinical routine enables the detection of significant complications. It is desirable to standardize the registration of postoperative complications to facilitate comparability across different institutions. The results may contribute to national or international databases used for automated AI risk profiling.

Adverse events after surgery for injuries to the subaxial cervical spine: analysis of incidence and risk factors

PURPOSE

To determine the incidence of severe surgical adverse events (sSAE) after surgery of patients with subaxial cervical spine injury (sCS-Fx) and to identify patient, treatment, and injury-related risk factors.

METHODS

Retrospective analysis of clinical and radiological data of sCS-Fx patients treated surgically between 2010 and 2020 at a single national trauma center. Baseline characteristics of demographic data, preexisting conditions, treatment, and injury morphology were extracted. Incidences of sSAEs within 60 days after surgery were analyzed. Univariate analysis and binary logistic regression for the occurrence of one or more sSAEs were performed to identify risk factors. P-values < .05 were considered statistically significant.

RESULTS

Two hundred and ninety-two patients were included. At least one sSAE occurred in 49 patients (16.8%). Most frequent were sSAEs of the surgical site (wound healing disorder, infection, etc.) affecting 29 patients (9.9%). Independent potential risk factors in logistic regression were higher age (OR 1.02 [1.003-1.04], p = .022), the presence of one or more modifiers in the AO Spine Subaxial Injury Classification (OR 2.02 [1.03-3.96], p = .041), and potentially unstable or unstable facet injury (OR 2.49 [1.24-4.99], p = .010). Other suspected risk factors were not statistically significant, among these Injury Severity Score, the need for surgery for concomitant injuries, the primary injury type according to AO Spine, and preexisting medical conditions.

CONCLUSION

sSAE rates after treatment of sCS-Fx are high. The identified risk factors are not perioperatively modifiable, but their knowledge should guide intra and postoperative care and surgical technique.

Positive Bacterial Cultures on Spinal Wound Closure Do Not Predict Postoperative Outcomes

BACKGROUND

Complex surgical back wounds represent significant morbidity in patients who have undergone spinal procedures requiring closure or revision by plastic surgeons. This study aimed to assess the utility of bacterial wound culture data for predicting surgical outcomes of wound management.

METHODS

This study is a single-institution retrospective review of consecutive patients who required plastic surgery intervention for wound infection following spinal procedures between the years 2010 and 2021 (n = 70). Statistical analysis was performed for demographics, comorbidities, perioperative laboratory studies, and treatment methods. The primary outcomes of interest were rate of postoperative complications after soft tissue reconstruction and reconstructive failure. The secondary outcome of interest was time to healing in number of days.

RESULTS

The overall complication rate after wound closure was 31.4%, with wound infection in 12.9%, seroma in 10%, dehiscence in 12.9%, and hematoma in 1.4%. Increasing number of debridements before wound closure increased the likelihood of a surgical complication of any kind (odds ratio [OR], 1.772; 95% confidence interval [CI], 1.045-3.002). Positive wound cultures before reconstruction were associated with development of seroma only (OR, 0.265; 95% CI, 0.078-0.893). Use of incisional vacuum-assisted closure devices significantly decreased the odds of postoperative wound dehiscence (OR, 0.179; 95% CI, 0.034-0.904) and increased odds of healing (hazard ratio, 3.638; 95% CI, 1.547-8.613).

CONCLUSIONS

Positive wound cultures were not significantly associated with negative outcomes after complex closure or reconstruction of infected spinal surgical wounds. This finding emphasizes the importance of clinical judgment with a multidisciplinary approach to complex surgical back wounds over culture data for wound closure timing.

Systematic Review of Prophylactic Plastic Surgery Closure to Prevent Postoperative Wound Complications Following Spine Surgery

Spinal surgeries are increasingly performed in the United States, but complication rates can be unacceptably high at up to 26%. Consequently, plastic surgeons (PS) are sometimes recruited by spine surgeons (SS) for intraoperative assistance with soft tissue closures. An electronic multidatabase literature search was systematically conducted to determine whether spinal wound closure performed by PS minimizes postoperative wound healing complications when compared to closure by SS (neurosurgical or orthopedic), with the hypothesis that closures by PS minimizes incidence of complications. All published studies involving patients who underwent posterior spinal surgery with closure by PS or SS at index spine surgery were identified. Filtering by exclusion criteria identified 10 studies, 4 of which were comparative in nature and included both closures by PS and SS. Of these 4, none reported significant differences in postoperative outcomes between the groups. Across all studies, PS were involved in cases with higher baseline risk for wound complications and greater comorbidity burden. Closures by PS were significantly more likely to have had prior chemotherapy in 2 of the 4 (50%) studies (P = 0.014, P < 0.001) and radiation in 3 of the 4 (75%) studies (P < 0.001, P < 0.01, P < 0.001). In conclusion, closures by PS are frequently performed in higher risk cases, and use of PS in these closures may normalize the risk of wound complications to that of the normal risk cohort, though the overall level of evidence of the published literature is low.

Clinical Considerations and Outcomes for Spine Surgery Patients with a History of Transplant: A Systematic Scoping Review

OBJECTIVE

The objective of this study was to investigate the perioperative management and outcomes of patients with a prior history of successful transplantation undergoing spine surgery.

METHODS

We searched Medline, Embase, and Cochrane Central Register of Controlled Trials for matching reports in July 2021. We included case reports, cohort studies, and retrospective analyses, including terms for various transplant types and an exhaustive list of key words for various forms of spine surgery.

RESULTS

We included 45 studies consisting of 34 case reports (published 1982-2021), 3 cohort analyses (published 2005-2006), and 8 retrospective analyses (published 2006-2020). The total number of patients included in the case reports, cohort studies, and retrospective analysis was 35, 48, and 9695, respectively. The mean 1-year mortality rate from retrospective analyses was 4.6% ± 1.93%, while the prevalence of perioperative complications was 24%. Cohort studies demonstrated an 8.5% ± 12.03% 30-day readmission rate. The most common procedure performed was laminectomy (38.9%) among the case reports. Mortality after spine surgery was noted for 4 of 35 case report patients (11.4%).

CONCLUSIONS

This is the first systematic scoping review examining the population of transplant patients with subsequent unrelated spine surgery. There is significant heterogeneity in the outcomes of post-transplant spine surgery patients. Given the inherent complexity of managing this group and elevated mortality and complications compared to the general spine surgery population, further investigation into their clinical care is warranted.

Prophylactic Muscle Flaps Decrease Wound Complication Rates in Patients with Oncologic Spine Disease

BACKGROUND

Patients with oncologic spine disease face a high systemic illness burden and often require surgical intervention to alleviate pain and maintain spine stability. Wound healing complications are the most common reason for reoperation in this population and are known to impact quality of life and initiation of adjuvant therapy. Prophylactic muscle flap (MF) closure is known to reduce wound healing complications in high-risk patients; however, the efficacy in oncologic spine patients is not well established.

METHODS

A collaboration at our institution presented an opportunity to study the outcomes of prophylactic MF closure. The authors performed a retrospective cohort study of patients who underwent MF closure versus a cohort who underwent non-MF closure in the preceding time. Demographic and baseline health data were collected, as were postoperative wound complication data.

RESULTS

A total of 166 patients were enrolled, including 83 patients in the MF cohort and 83 control patients. Patients in the MF group were more likely to smoke ( P = 0.005) and had a higher incidence of prior spine irradiation ( P = 0.002). Postoperatively, five patients (6%) in the MF group developed wound complications, compared with 14 patients (17%) in the control group ( P = 0.028). The most common overall complication was wound dehiscence requiring conservative therapy, which occurred in six control patients (7%) and one MF patient (1%) ( P = 0.053).

CONCLUSIONS

Prophylactic MF closure during oncologic spine surgery significantly reduces the wound complication rate. Future studies should examine the precise patient population that stands to benefit most from this intervention.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Early Outcomes of Muscle Flap Closures in Posterior Thoracolumbar Fusions: A Propensity-Matched Cohort Analysis

BACKGROUND

Plastic surgery closure with muscle flaps after complex spinal reconstruction has become increasingly common. Existing evidence for this practice consists of small, uncontrolled, single-center cohort studies. We aimed to compare 30-day postoperative wound-related complication rates between flap closure and traditional closure after posterior thoracolumbar fusions (PTLFs) for non-infectious, non-oncologic pathologies using a national database.

METHODS

We performed a propensity-matched analysis using the 2012-2020 National Surgical Quality Improvement Program dataset to compare 30-day outcomes between PTLFs with flap closure versus traditional closure.

RESULTS

A total of 100,799 PTLFs met our inclusion criteria. The use of flap closure with PTLF remained low but more than doubled from 2012 to 2020 (0.38% vs. 0.97%; P = 0.002). A higher proportion of flap closures had higher American Society of Anesthesiologists classifications and higher number of operated spine levels (all P < 0.001). We included 1907 PTLFs (630 for flap closure; 1257 for traditional closure) in the propensity-matched cohort. Unadjusted 30-day wound complication rates were 1.7% for flap and 2.1% for traditional closure (P = 0.76). After adjusting for operative time, wound complication, readmission, reoperation, mortality, and non-wound complication were not associated flap use (all P > 0.05).

CONCLUSIONS

Plastic surgery closure was performed in patients with a higher comorbidity burden, suggesting consultation in sicker patients. Although higher rates of wound and non-wound complications were expected for the flap cohort, our propensity-matched cohort analysis of flap closure in PTLFs resulted in non-inferior odds of wound complications compared to traditional closure. Further study is needed to assess long-term complications in prophylactic flap closure in complex spine surgeries.

Augmented and virtual reality in spine surgery

Augmented Reality (AR) and Virtual Reality (VR) have developed unprecedentedly in recent years, providing interesting opportunities for medical applications. Their integration into clinical assessment, surgical workflow, and training has shown tremendous potential to improve daily life activity in spine surgery. The paper explores the utilization of VR and AR in spine surgery, with their applications, benefits, challenges, and forthcoming prospects.

Plastic multilayered closure versus orthopedic surgeon closure after spinal instrumentation in pediatric neuromuscular scoliosis

Objective

To compare wound complication rates between orthopedic closure (OC) and plastic multilayered closure (PMC) in patients undergoing primary posterior spinal fusion for neuromuscular scoliosis (NMS). We hypothesize that multilayered closure will be associated with better postoperative outcomes.

Methods

We collected data on pediatric patients diagnosed with NMS who underwent first time spinal instrumentation between 1 January 2018 and 31 May 2021. Patient demographics, length of surgery, spinal levels fused and operative variables, wound complication rate, treatments, and need for wound washout were reviewed in depth and recorded.

Results

In total, 86 patients were reviewed: 46 with OC and 40 with PMC. There was a significant increase in operating room (OR) time with PMC compared with OC (6.7±1.2 vs 7.3±1.3, p=0.016). There was no difference in complication rate, mean postoperative day of complication or unplanned return to the OR for OC and PMC, respectively. There was a slightly significant increase in the number of patients going home with a drain in the PMC cohort compared with the OC cohort (2.1% vs 15%, p=0.046).

Conclusions

PMC demonstrated longer OR times than OC and did not demonstrate a statistically significant reduction in wound complications or unplanned returns to the OR. However, other studies have demonstrated statistical and clinical significance with these variables. Surgical programs should review internal patient volumes and outcomes for spinal fusion in NMS patients and consider if PMC after spinal fusions in pediatric patients with NMS or other scoliosis subtypes is an appropriate option in their institution to minimize postoperative wound complications.

The 5-Item Modified Frailty Index Independently Predicts Morbidity in Patients Undergoing Instrumented Fusion following Extradural Tumor Removal

Introduction

The management of spinal neoplasia consists of surgical, radiation, and systemic options. Little data exist to guide management based on overall health status, which is particularly challenging when patients who could benefit from surgery may be too frail for it. This study's objective was to evaluate the 5-Item Modified Frailty Index (mFI-5) as a predictor of 30-day morbidity in patients undergoing instrumented resection for metastatic extradural spinal tumors.

Methods

Adults undergoing extradural tumor resection from the 2011 to 2019 National Surgical Quality Improvement Program datasets were identified by Current Procedural Terminology codes 63275-63278 with an adjunct instrumentation code (22840-22843). Patients were classified into frailty levels 0, 1, or 2+ based on mFI-5 scores of 0, 1, or 2-5, respectively. The primary outcome was morbidity. Secondary outcomes were readmission and reoperation. Multivariate modeling was utilized to analyze mFI-5 as a predictor of outcomes. The Akaike information criterion (AIC) was used to compare relative-model-fit based on frailty versus individual comorbidity variables to determine the optimal model. Chi-squared and Fisher's exact tests were used to establish significance between individual complications and frailty.

Results

There were 874 patients. Readmission, reoperation, and morbidity rates were 19.5%, 5.0%, 52.3%, respectively. In multivariate analyses, mFI-5=1 (OR: 1.45, SE: 0.31, p=0.036), mFI-5=2+ (OR: 1.41, SE: 0.40, p=0.036), operative time (OR: 1.18, SE: 0.03, p≤0.001), and chronic steroid use (OR: 1.56, SE: 0.42, p=0.037) independently predicted morbidity. Elective surgery (OR: 0.61) was protective. Frailty did not predict readmission or reoperation. Frailty was found to be significantly associated with respiratory complications, urinary tract infections, cardiac events, and sepsis/septic shock specifically.

Conclusions

mFI-5=1 independently predicted 45% increased odds of morbidity. mFI-5=2+ independently predicted 41% increased odds of morbidity. Further, every 30 additional minutes of operative time predicted 18% increased odds of morbidity, suggesting an increased risk of site-related complication events. Taken together, the mFI-5 serves as a valid predictor of morbidity in patients with extradural tumor undergoing instrumented excision.

Muscle Flap Closures in Spine Surgery: Predictors of Usage Patterns and Factors Associated With Postoperative Complications From the NSQIP Database

STUDY DESIGN

Retrospective cohort study using the National Surgical Quality Improvement Program.

OBJECTIVE

The objective of this study was to identify preoperative factors that impact the decision to perform prophylactic muscle flap closure and assess risk factors for wound healing complications in patients undergoing spinal procedures with and without muscle flap closure.

SUMMARY OF BACKGROUND DATA

Prior studies suggest that muscle flap closure following complex spine surgery results in a lower risk of wound healing complications. However, these studies have been limited to single institutions and/or surgeons.

METHODS

The National Surgical Quality Improvement Program database was queried for all patients undergoing spine surgery between 2005 and 2017 with and without concomitant muscle flaps. Preoperative and perioperative variables were extracted. Univariate and multivariate analyses were performed to assess risk factors influencing surgical site infection (SSI) and wound disruption, as well as to delineate which preoperative factors increased the likelihood of patients receiving flap closures a priori.

RESULTS

Concomitant muscle flaps were performed on 758 patients; 301,670 patients did not receive a flap. Overall 29 (3.83%) patients in the flap group experienced SSI compared to 5154 (1.71%) in the nonflap group (P<0.0001). Preoperative steroid use [odds ratio (OR) 0.5; P<0.0001], wound infection (OR 0.24; P<0.0001), elevated white blood cell count (OR 1.034; P<0.0001), low hematocrit (OR 0.94; P<0.0001), preoperative transfusion (OR 0.22; P=0.0068) were significantly associated with utilization of muscle flaps. Perioperative factors including a contaminated wound (OR 4.72; P<0.0001), the American Society of Anesthesiologists classification of severe disease (OR 1.92; P=0.024), and longer operative time (OR 1.001; P=0.0024) were significantly associated with postoperative wound disruption. In addition, after propensity score matching for these factors that increase risk of wound complications, there was no difference in the rates of SSI between the flap and nonflap group.

CONCLUSION

Our results suggest that patients with a higher burden of illness preoperatively are more likely to receive prophylactic paraspinal flaps which can reduce the rates of wound-related complications.

Cervical Spine Injuries with Acute Traumatic Spinal Cord Injury: Spinal Surgery Adverse Events and Their Association with Neurological and Functional Outcome

STUDY DESIGN

Monocenter case-control study.

OBJECTIVE

Effects of spinal surgical adverse events (SSAE) on clinical and functional outcome, length of stay, and treatment costs after traumatic cervical spinal cord injury (SCI).

SUMMARY OF BACKGROUND DATA

Traumatic SCI is a challenge for primary care centers because of the emergency setting and complex injury patterns. SSAE rates of up to 15% are reported for spine fractures without SCI. Little is known about SSAE after traumatic SCI and their outcome relevance.

METHODS

Acute traumatic cervical SCI patients were enrolled from 2011 to 2017. Cases with and without SSAE were compared regarding neurological recovery, functional outcome, secondary complications, mortality, length of stay, and treatment costs. Adjusted logistic regression and generalized estimating equation models were calculated for the endpoints ASIA impairment scale (AIS)-conversion and dysphagia. All analyses were run in the total and in a propensity score matched sample.

RESULTS

At least one SSAE occurred in 37 of 165 patients (22.4%). Mechanical instability and insufficient spinal decompression were the most frequent SSAE with 13 (7.9%) or 11 (6.7%) cases, respectively. The regression models adjusted for demographic, injury, and surgery characteristics demonstrated a reduced probability for AIS-conversion related to SSAE (OR [95% CI] 0.14 [0.03-0.74]) and additionally to single-sided ventral or dorsal surgical approach (0.12 [0.02-0.69]) in the matched sample. Furthermore, SSAE were associated with higher risk for dysphagia in the matched (4.77 [1.31-17.38]) and the total sample (5.96 [2.07-17.18]). Primary care costs were higher in cases with SSAE (median (interquartile range) 97,300 [78,200-112,300]) EUR compared with cases without SSAE (52,300 [26,700-91,200]) EUR.

CONCLUSION

SSAE are an important risk factor after acute traumatic cervical SCI with impact on neurological recovery, functional outcome, and healthcare costs. Reducing SSAE is a viable means to protect the limited intrinsic capacity for recovery from SCI.Level of Evidence: 4.

What is the role of incisional vacuum therapy in challenging spinal wounds? A single centre experience

OBJECTIVE

A surgical approach to the treatment of spinal defects and disorders has become more common because of the medical and technological advancements achieved in the last decade. This rising trend in spinal surgeries is associated with adverse events, most notably wound complications. From its introduction, negative pressure wound therapy (NPWT) has proved to be essential in the management of complex wounds and in speeding up wound recovery. The aim of this study is to investigate the use of incisional NPWT in patients undergoing spinal surgery and its role in the prevention of wound complications.

METHOD

This study is a retrospective medical chart review conducted on patients who underwent spinal surgery and received incisional vacuum therapy as part of their treatment. The apparatus was applied intraoperatively following the spinal surgery for all patients included in this study. All surgical procedures were conducted between September 2019 and May 2020. Data entry and analysis were performed between September and October 2020.

RESULTS

A total of five patients' records were reviewed. In our healthcare centre, three patients developed seroma, one developed haematoma, four required revision surgery and one patient required re-operation. There was no wound dehiscence and none of the wounds became infected. Mean length of hospital stay was 11.2 days (standard deviation (SD): 9.5 days) and mean operation time was 333 minutes (SD: 86.4 minutes).

CONCLUSION

There is a scarcity of data on the role of incisional vacuum therapy in the prevention of wound complications associated with spine surgeries. Our study showed promising results for the use of incisional NPWT in the management of spinal wounds. Further research is required in order to enhance wound care by exploiting this potentially beneficial approach.

Systematic review and evaluation of predictive modeling algorithms in spinal surgeries

In order to better educate patients, predictive models have been implemented to stratify surgical risk, thereby instituting greater uniformity across surgical practices and prioritizing the safety and outcomes of patients. The purpose of this study is to conduct a systematic review summarizing the major predictive models used to evaluate patients as candidates for spinal surgery. A search was conducted for articles related to predictive modeling in spinal surgeries using PubMed, MEDLINE, and Scopus databases. Papers with area under the receiver operating curve (AUROC) scores reported were included in the analysis. Models not relevant to spinal procedures were excluded. Comparison between models was only attainable for those that reported AUROCs for individual procedures. Based on a combination of AUROC scores and demonstrated applicability to spinal procedures, the models by Scheer et al. (0.89), Ratliff et al. (0.70), the Seattle Spine Score (0.712), Risk Assessment Tool (0.67-0.7), and the Spine Sage calculator (0.81-0.85) were determined to be ideal for predictive modeling in spinal surgeries and were subsequently broken down into their individual inputs and outputs to determine what elements a theoretical model should assimilate. Alongside the model by Scheer et al., the Spine Sage calculator, Seattle Spine Score, Risk Assessment Tool, and a model by Ratliff et al. showed the most promise for patients undergoing spinal procedures. Using the first model as a springboard, new spinal predictive models can be optimized through use of larger prospective databases, with longer follow-up times, and greater inclusion of reliable high impact variables.

The role of the plastic surgeon in wound repair after spinal surgery

BACKGROUND

Wound complications, including dehiscence and surgical site infections, following spinal surgery have the potential to be devastating both to the patient and to the hospital system. Complications can occur in a wide range of patients including diabetics, those of low or high BMI and those of old age. Obese patients and those with increased subcutaneous fat are at particularly high risk for wound complications, which may be mitigated through use of local flap reconstruction by a Plastic Surgeon.

CASE DESCRIPTION

A 28 year-old female with morbid obesity presents with multiple lumbar transverse process fractures and complex sacral and pelvic fractures requiring closed reduction and percutaneous fixation of the pelvic ring followed by posterior spinal fusion. The patient was closed tension-free by the neurosurgery team and ultimately dehisced requiring consultation and management by Plastic Surgery.

OUTCOME

The patient underwent debridement and reconstruction with a gluteus maximus myocutaneous flap advancement without complication.

CONCLUSIONS

Wound management after spinal surgery is a complex problem, which may be prophylaxed through early identification of high-risk patients and preoperative consultation of Plastic Surgery. Patients with increased thickness of subcutaneous fat are at particularly high risk for postoperative complications, including infection and dehiscence, secondary to increased tissue manipulation and necrosis.

The Value of Plastic Surgery Spinal Closures: A Review of 782 Spine Cases

BACKGROUND

The role of the plastic surgeon in wound management after complications from previous spinal surgeries is well established.

PURPOSE

The present study evaluates wound complications after plastic surgeon closure of the primary spinal surgery in a large patient population.

STUDY DESIGN AND SETTING

This is a retrospective review of spine surgery patients undergoing plastic surgeon closure of spine surgeries at a single tertiary care center.

PATIENT SAMPLE

Spine surgery patients included those who were referred for plastic surgeon closure due to (a) concerns about patient healing potential, (b) concerns about difficulty of closure, (c) patient request, or (d) difficulties with closure intraoperatively.

OUTCOME MEASURES

The outcomes are physiologic measures, including intraoperative and postoperative complications, hospital length of stay, and 30-day readmissions and reoperations.

METHODS

Outcomes in this sample were compared with previously published outcomes using 2-sample z tests. The authors have no conflicts of interest.

RESULTS

Nine hundred twenty-eight surgeries were reviewed, of which 782 were included. Fourteen patients (1.8%) required readmission with 30 days. This compares favorably to a pooled analysis of 488,049 patients, in which the 30-day readmission rate was found to be 5.5% (z = 4.5, P < 0.0001). Seven patients (0.89%) had wound infection and 3 (0.38%) wound dehiscence postoperatively, compared with a study of 22,430 patients in the American College of Surgeons National Surgery Quality Improvement Program database, which had an infection incidence of 2.2% (z = 2.5, P = 0.0132) and 0.3% dehiscence rate (z = 0.4, P = 0.6889). The combined incidence of wound complications in the present sample was 1.27%, which is less than the combined incidence of wound complications in the population of 22,430 patients (z = 2.2, P = 0.029).

CONCLUSIONS

Thirty-day readmissions and wound complications are intensely scrutinized quality metrics that may lead to reduced reimbursements and other penalties for hospitals. Plastic surgeon closure of index spinal cases decreases these adverse outcomes. Further research must be conducted to determine whether the increased cost of plastic surgeon involvement in these cases is offset by the savings represented by fewer readmissions and complications.

Can the Charlson Comorbidity Index be used to predict the ASA grade in patients undergoing spine surgery?

BACKGROUND

The American Society of Anaesthesiologists' Physical Status Score (ASA) is a key variable in predictor models of surgical outcome and "appropriate use criteria". However, at the time when such tools are being used in decision-making, the ASA rating is typically unknown. We evaluated whether the ASA class could be predicted statistically from Charlson Comorbidy Index (CCI) scores and simple demographic variables.

METHODS

Using established algorithms, the CCI was calculated from the ICD-10 comorbidity codes of 11'523 spine surgery patients (62.3 ± 14.6y) who also had anaesthetist-assigned ASA scores. These were randomly split into training (N = 8078) and test (N = 3445) samples. A logistic regression model was built based on the training sample and used to predict ASA scores for the test sample and for temporal (N = 341) and external validation (N = 171) samples.

RESULTS

In a simple model with just CCI predicting ASA, receiver operating characteristics (ROC) analysis revealed a cut-off of CCI ≥ 1 discriminated best between being ASA ≥ 3 versus < 3 (area under the curve (AUC), 0.70 ± 0.01, 95%CI,0.82-0.84). Multiple logistic regression analyses including age, sex, smoking, and BMI in addition to CCI gave better predictions of ASA (Nagelkerke's pseudo-R² for predicting ASA class 1 to 4, 46.6%; for predicting ASA ≥ 3 vs.  < 3, 37.5%). AUCs for discriminating ASA ≥ 3 versus < 3 from multiple logistic regression were 0.83 ± 0.01 (95%CI, 0.82-0.84) for the training sample and 0.82 ± 0.01 (95%CI, 0.81-0.84), 0.85 ± 0.02 (95%CI, 0.80-0.89), and 0.77 ± 0.04 (95%CI,0.69-0.84) for the test, temporal and external validation samples, respectively. Calibration was adequate in all validation samples.

CONCLUSIONS

It was possible to predict ASA from CCI. In a simple model, CCI ≥ 1 best distinguished between ASA ≥ 3 and < 3. For a more precise prediction, regression algorithms were created based on CCI and simple demographic variables obtainable from patient interview. The availability of such algorithms may widen the utility of decision aids that rely on the ASA, where the latter is not readily available.

Muscle Flap Closure following Complex Spine Surgery: A Decade of Experience

BACKGROUND

Advances in surgical technology and adjuvant therapies along with an aging and increasingly morbid U.S. population have led to an increase in complex spine surgery. With this increase comes an elevated risk of complications, including those related to the surgical wound, with some studies demonstrating wound complication incidences approaching 45 percent. The authors hypothesize that immediate muscle flap closure improves outcomes in high-risk patients.

METHODS

Three hundred one consecutive index cases of spinal wound closure using local muscle flaps performed by the senior author at a single institution between 2006 and 2018 were reviewed. The primary outcome was major wound complication (reoperation and/or readmission because of surgical-site infection, late infection, dehiscence, seroma, or hematoma). Logistic regression analysis was performed to identify predictors of this endpoint.

RESULTS

Major wound complications occurred in 6.6 percent of patients (reoperation, 3.6 percent; readmission, 3.0 percent), with a 6.0 percent infection rate and five cases requiring instrumentation removal because of infection. Risk factors identified included radiotherapy (OR, 5.9; p = 0.004), age 65 years or older (OR, 2.8; p = 0.046), and prior spine surgery (OR, 4.3; p = 0.027). The incidence of major wound complication increased dramatically with each additional risk factor. Mean drain dwell duration was 21.1 ± 10.0 days and not associated with major wound complications, including infection (OR, 1.04; p = 0.112).

CONCLUSIONS

Immediate local muscle flap closure following complex spine surgery on high-risk patients is associated with an acceptable rate of wound complications and, as these data demonstrate, is safe and effective. Consideration should be given to immediate muscle flap closure in appropriately selected patients.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Evaluation of Predictive Models for Complications following Spinal Surgery

BACKGROUND

 Complications rates vary across spinal surgery procedures and are difficult to predict due to heterogeneity in patient characteristics, surgical methods, and hospital volume. Incorporation of predictive models for complications may guide surgeon decision making and improve outcomes.

METHODS

 We evaluate current independently validated predictive models for complications in spinal surgery with respect to study design and model generation, accuracy, reliability, and utility. We conducted our search using Preferred Reporting Items for Systematic Review and Meta-analysis guidelines and the Participants, Intervention, Comparison, Outcomes, Study Design model through the PubMed and Ovid Medline databases.

RESULTS

 A total of 18 articles met inclusion criteria including 30 validated predictive models of complications after adult spinal surgery. National registry databases were used in 12 studies. Validation cohorts were used in seven studies for verification; three studies used other methods including random sample bootstrapping techniques or cross-validation. Reported area under the curve (AUC) values ranged from 0.37 to 1.0. Studies described treatment for deformity, degenerative conditions, inclusive spinal surgery (neoplasm, trauma, infection, deformity, degenerative), and miscellaneous (disk herniation, spinal epidural abscess). The most commonly cited risk factors for complications included in predictive models included age, body mass index, diabetes, sex, and smoking. Those models in the deformity subset that included radiographic and anatomical grading features reported higher AUC values than those that included patient demographics or medical comorbidities alone.

CONCLUSIONS

 We identified a cohort of 30 validated predictive models of complications following spinal surgery for degenerative conditions, deformity, infection, and trauma. Accurate evidence-based predictive models may enhance shared decision making, improve rehabilitation, reduce adverse events, and inform best practices.

Immediate plastic surgery closure at index spinal surgery minimizes complications compared to delayed reconstruction: A retrospective cohort review

BACKGROUND

Complex spine surgery in patients with major comorbidities leads to increased need for midline back wound reconstruction by plastic surgeons. Literature suggests that back wound reconstruction concurrent with high-risk immediate/index spine surgery may lead to fewer complication. This study aimed to validate this claim in a large cohort treated at a tertiary center. We hypothesize that immediate reconstruction may lead to fewer adverse events in comparison to delayed reconstruction.

METHODS

This was a retrospective single-center review of 659 patients who underwent spinal surgery with/without reconstruction by plastic surgeons between November 2011 and December 2015. Three main cohorts were evaluated: patients who underwent spinal surgery with no reconstruction, patients with delayed reconstruction after spine surgery, and patients with immediate back wound reconstruction with index spine surgery. Demographic, clinical, and outcomes data were collected from electronic medical records. Primary endpoints were the incidence of any complications such as dehiscence, infection, seroma/hematoma, and exposed hardware. The secondary endpoint was return to the operating room and most recent follow-up.

RESULTS

Forty-three patients underwent index reconstruction (follow-up 25.3 ± 12.7 months), 33 were delayed (follow-up 23.7 ± 12.5 months), and 583 had no reconstruction (follow-up 22.1 ± 15.2 months). Patients who underwent index reconstruction had more spinal levels involved than delayed reconstruction (7.8 ± 0.75 vs 5.6 ± 0.68; p = 0.03). The overall complications rate was 7.7%, most commonly wound dehiscence (2.7%), infections (0.9%), exposed hardware (2.0%), cerebrospinal fluid leaks (0.6%), and return to OR (3.8%). Patients who underwent index spinal wound reconstruction had a significantly lower complication rate (4.65%) than secondary spinal surgery patients (27.3%; p = 0.048).

CONCLUSIONS

The data confirmed significantly decreased complication rates for index back wound reconstructions for high-risk patients compared to delayed spine wound reconstruction. Increased rates of wound dehiscence, exposed hardware, and revisions occurred with delayed reconstruction. Early employment of tension free, robust vascular flap closure may attribute to a decreased complication profile.

Locoregional Flap Closure for High-risk Multilevel Spine Surgery

Background:

Postoperative wound complications pose a challenge to patients undergoing complex spine surgery. Long-term sequelae can be devastating including decreased quality of life, meningitis, prolonged hospital stay, and need for reoperation. Among high-risk patients, postoperative wound complications have been shown to approach 40% in the literature. The aim of this study was to identify predictive factors for postoperative complications following soft-tissue reconstruction after high-risk spine surgery with the hypothesis that it would result in significantly fewer postoperative wound complications.

Methods:

A retrospective review of 67 consecutive spine operations at an academic, tertiary care center was performed, evaluating outcomes with a single plastic surgeon in conjunction with the spine surgery team. Data regarding patient demographics, perioperative risk variables, flap type, location of defect, and postoperative outcomes were obtained through retrospective chart review. Complications included soft-tissue complications and a number of reoperations. A bivariate analysis was used to identify predictors of postoperative complication. These data were compared to literature-reported averages.

Results:

A total of 67 consecutive spinal reconstructive operations were included with a mean follow-up of 11.8 months. Thirty-seven patients (55.2%) underwent immediate reconstruction at the time of the index operation, and 30 (44.8%) underwent delayed reconstruction for secondary wound healing problems following the index operation (in which plastic surgery was not involved). The majority of both immediate (95%, n = 35) and delayed (100%, n = 30) patients was defined as high risk based on literature standards. Patients in this series demonstrated a 7.5% complication rate, compared to 18.7% complication rate in the literature. We did not find a difference between major wound complications in the immediate (8.1%) or delayed (6.7%) reconstructive setting (P > 0.99). There were no specific variables identified that predicted postoperative complications.

Conclusion:

This study illustrates a postoperative complication rate of 7.5% among patients undergoing paraspinous or locoregional muscle flap closure by plastic surgery, which is significantly lower than that reported in contemporary literature for these high-risk patients.

Differences in management of isolated spinal fractures between neurosurgery and orthopaedics: a 6-year retrospective study

INTRODUCTION

The acute management of spinal fractures is traditionally split between neurosurgeons and orthopaedic surgeons and the specialities have varying approaches to management. This study investigates differences between neurosurgeons and spinal orthopaedic surgeons in the management of spinal fractures at a single trauma centre in the United Kingdom.

METHODS

A retrospective study at a single trauma centre of patients identified using the Trauma Audit and Research Network (TARN). Case notes and radiological investigations were reviewed for demographics, fracture classification, clinical management and outcomes. Polytrauma cases and patients managed by non-neurosurgical/orthopaedic specialties were excluded.

RESULTS

A total of 465 patients were included in this study (neurosurgery n = 266, orthopaedics n = 199). There were no significant differences between groups for age, gender, Charlson co-morbidity score or distribution of fractures using the AO spine classification. Patients admitted and managed under the orthopaedic surgeons were more likely to undergo a surgical procedure when compared to those admitted under the neurosurgeons (n = 71; 35.7% vs n = 71; 26.8%, p = 0.042, OR 1.56 95%CI 1.056 to 2.31). The median overall length of stay was 8 days and there was no significant difference between teams; however, the neurosurgical cohort were more likely to be admitted to an intensive care unit (24.3% vs 16.2%, p = 0.04).

CONCLUSION

This study is the first in the United Kingdom to compare neurosurgical and orthopaedic teams in their management of spinal fractures. It demonstrates that differences may exist both in operating rates and outcomes.

Quality and Safety Improvement in Spine Surgery

STUDY DESIGN

Review article.

OBJECTIVES

A narrative review of the literature on the current advances and limitations in quality and safety improvement initiatives in spine surgery.

METHODS

A comprehensive literature search was performed using Ovid MEDLINE focusing on 3 preidentified concepts: (1) quality and safety improvement, (2) reporting of outcomes and adverse events, and (3) prediction model and practice guidelines. The search was conducted under appropriate subject headings and using relevant text words. Articles were screened, and manuscripts relevant to this discussion were included in the narrative review.

RESULTS

Quality and safety improvement remains a major research focus attracting investigators from the global spine community. Multiple databases and registries have been developed for the purpose of generating data and monitoring the progress of quality and safety improvement initiatives. The development of various prediction models and clinical practice guidelines has helped shape the care of spine patients in the modern era. With the reported success of exemplary programs initiated by the Northwestern and Seattle Spine Team, other quality and safety improvement initiatives are anticipated to follow. However, despite these advancements, the reporting metrics for outcomes and adverse events remain heterogeneous in the literature.

CONCLUSION

Constant surveillance and continuous improvement of the quality and safety of spine treatments is imperative in modern health care. Although great advancement has been made, issues with reporting outcomes and adverse events persist, and improvement in this regard is certainly needed.

Plastic Surgeon Closure of Index Spinal Cases: A Single-Institution Review of 928 Cases

PURPOSE

The role of the plastic surgeon in wound management following complications from prior spinal surgeries is well established. The present study evaluates wound complications following plastic surgeon closure of the primary spinal surgery in a large patient population.

METHODS

Spinal surgeries closed by a single plastic surgeon at a large academic hospital were reviewed. Descriptive statistics were applied and outcomes in this sample were compared with previously published outcomes using 2-sample z tests.

RESULTS

Nine hundred twenty-eight surgeries were reviewed, of which 782 were included. Seven hundred fifteen operations were for degenerative conditions of the spine, 22 for trauma, 30 for neoplasms, and 14 for congenital conditions. Four hundred twenty-one were lumbosacral procedures (53.8%) and 361 (46.2%) cervical. Fourteen patients (1.8%) required readmission with 30 days. This compares favorably to a pooled analysis of 488049 patients, in which the 30-day readmission rate was found to be 5.5% (z=4.5, P<0.0001). Seven patients (0.89%) had wound infection and 3 (0.38%) wound dehiscence postoperatively, compared with a study of 22,430 patients in the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database who had an infection incidence of 2.2% (z=2.5, P=0.0132) and 0.3% dehiscence rate (z=0.4, P=0.6889). The combined incidence of wound complications in the present sample, 1.27%, was less than the combined incidence of wound complications in the population of 22,430 patients (z=2.2, P=0.029).

CONCLUSIONS

Thirty-day readmissions and wound complications are intensely scrutinized quality metrics that may lead to reduced reimbursements and other penalties for hospitals. Plastic surgeon closure of index spinal cases decreases these adverse outcomes. Further research must be done to determine whether the increased cost of plastic surgeon involvement in these cases is offset by the savings represented by fewer readmissions and complications.

A machine learning approach for predictive models of adverse events following spine surgery

BACKGROUND

Rates of adverse events following spine surgery vary widely by patient-, diagnosis-, and procedure-related factors. It is critical to understand the expected rates of complications and to be able to implement targeted efforts at limiting these events.

PURPOSE

To develop and evaluate a set of predictive models for common adverse events after spine surgery.

STUDY DESIGN

A retrospective cohort study.

PATIENT SAMPLES

We extracted 345,510 patients from the Truven MarketScan (MKS) and MarketScan Medicaid Databases and 760,724 patients from the Centers for Medicare and Medicaid Services (CMS) Medicare database who underwent spine surgeries between 2009 and 2013.

OUTCOME MEASURES

Overall adverse event (AE) occurrence and types of AE occurrence during the 30-day postoperative follow-up.

METHODS

We applied a least absolute shrinkage and selection operator regularization method and a logistic regression approach for predicting the risks of an overall AE and the top six most commonly observed AEs. Predictors included patient demographics, location of the spine procedure, comorbidities, type of surgery performed, and preoperative diagnosis.

RESULTS

The median ages of MKS and CMS patients were 49 years and 69, respectively. The most frequent individual AE was a cardiac dysfunction in CMS (10.6%) patients and a pulmonary complication (4.7%) in MKS. The area under the curve (AUC) of a prediction model for an overall AE was 0.7. Among the six individual prediction models, the model for predicting the risk of a pulmonary complication showed the greatest accuracy (AUC 0.76), and the range of AUC for these six models was 0.7 and 0.76. Medicaid status was one of the most important factors in predicting the occurrences of AEs; Medicaid recipients had increased odds of AEs by 20%-60% compared with non-Medicaid patients (odds ratios 1.28-1.6; p<10^-10). Logistic regression showed higher AUCs than least absolute shrinkage and selection operator across these different models.

CONCLUSIONS

We present a set of predictive models for AEs following spine surgery that account for patient-, diagnosis-, and procedure-related factors which can contribute to patient-counseling, accurate risk adjustment, and accurate quality metrics.

Preoperative Risk Stratification in Spine Tumor Surgery: A Comparison of the Modified Charlson Index, Frailty Index, and ASA Score

STUDY DESIGN

A retrospective review of prospectively collected data.

OBJECTIVE

The purpose of this study is to compare and validate several preoperative scores for predicting outcomes following spine tumor resection.

SUMMARY OF BACKGROUND DATA

Preoperative risk assessment for patients undergoing spinal tumor resection remains challenging. At present, few risk assessment tools have been validated in this high-risk population.

METHODS

The 2008 to 2014 National Surgical Quality Improvement database was used to identify all patients undergoing surgical resection of spinal tumors, stratified as extradural, intradural extramedullary, and intramedullary based on CPT codes. American Society of Anesthesiologists (ASA) score, modified Charlson Comorbidity Index (CCI), and modified Frailty Index (mFI) were computed. A binary logistic regression model was used to explore the relationship between these variables and postoperative outcomes, including mortality, major and minor adverse events, and hospital length of stay (LOS). Other significant variables such as demographics, operative time, and tumor location were controlled for in each model.

RESULTS

Two thousand one hundred seventy patients met the inclusion criteria. Higher CCI scores were independent predictors of mortality (OR = 1.24, 95% CI: 1.14-1.36, P < 0.001), major adverse events (OR = 1.07, 95% CI: 1.01-1.31, P = 0.018), minor adverse events (OR = 1.15, 95% CI: 1.10-1.20, P < 0.001), and prolonged LOS (OR = 1.14, 95% CI: 1.09-1.19, P < 0.001). Patients' mFI scores were significantly associated with mortality and LOS, but not major or minor adverse events. ASA scores were not associated with any outcome metric when controlling for other variables.

CONCLUSION

The CCI demonstrated superior predictive capacity compared with mFI and ASA scores and may be valuable as a preoperative risk assessment tool for patients undergoing surgical resection of spinal tumors. The validation of assessment scores is important for preoperative risk stratification and improving outcomes in this high-risk group.

LEVEL OF EVIDENCE

3.

Reporting Methodology of Neurosurgical Studies Utilizing the American College of Surgeons-National Surgical Quality Improvement Program Database: A Systematic Review and Critical Appraisal

BACKGROUND

Use of large databases such as the American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) has become increasingly common in neurosurgical research.

OBJECTIVE

To perform a critical appraisal and evaluation of the methodological reporting for studies in neurosurgical literature that utilize the ACS-NSQIP database.

METHODS

We queried Ovid MEDLINE, EMBASE, and PubMed databases for all neurosurgical studies utilizing the ACS-NSQIP. We assessed each study according to number of criteria fulfilled with respect to Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement, REporting of studies Conducted using Observational Routinely-collected Health Data (RECORD) Statement, and Journal of American Medical Association–Surgical Section (JAMA-Surgery) Checklist. A separate analysis was conducted among papers published in core and noncore journals in neurosurgery according to Bradford's law.

RESULTS

A total of 117 studies were included. Median (interquartile range [IQR]) scores for number of fulfilled criteria for STROBE Statement, RECORD Statement, and JAMA-Surgery Checklist were 20 (IQR:19-21), 9 (IQR:8-9), and 6 (IQR:5-6), respectively. For STROBE Statement, RECORD Statement, and JAMA-Surgery Checklist, item 9 (potential sources of bias), item 13 (supplemental information), and item 9 (missing data/sensitivity analysis) had the highest number of studies with no fulfillment among all studies (56, 68, 50%), respectively. When comparing core journals vs noncore journals, no significant difference was found (STROBE, P = .94; RECORD, P = .24; JAMA-Surgery checklist, P = .60).

CONCLUSION

While we observed an overall satisfactory reporting of methodology, most studies lacked mention of potential sources of bias, data cleaning methods, supplemental information, and external validity. Given the pervasive role of national databases and registries for research and health care policy, the surgical community needs to ensure the credibility and quality of such studies that ultimately aim to improve the value of surgical care delivery to patients.

Clinical Outcomes Associated With Allogeneic Red Blood Cell Transfusions in Spinal Surgery: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

The objectives of this systematic review were to report the available clinical evidence on patient outcomes associated with perioperative allogeneic red blood cell (RBC) transfusions in adult patients undergoing spinal surgery and to determine whether there is any evidence to support an association between transfusion timing and clinical outcomes.

METHODS

A systematic review of the PubMed, EMBASE, and Cochrane Library databases was performed to identify all articles examining outcomes of adult spinal surgery patients who received perioperative allogeneic RBC transfusions. The level of evidence for each study was assessed using the "Oxford Levels of Evidence 2" classification system. Meta-analysis was not performed due to the heterogeneity of reports.

RESULTS

A total of 2759 unique citations were identified and 76 studies underwent full-text review. Thirty-four studies were selected for analysis. All the studies, except one, were retrospective. Eleven studies investigated intraoperative or postoperative transfusions. Only one article compared outcomes related to intraoperative versus postoperative transfusions.

CONCLUSIONS

Perioperative transfusion is associated with increased rates of postoperative complications, especially infectious complications, and prolonged length of stay. Some evidence suggests that a dose-response relationship may exist between morbid events and the number of RBC units administered, but these findings are inconsistent. Because of the heterogeneity of reports and inconsistent findings, the incidence of specific complications remains unclear. Limited research activity has focused on intraoperative versus postoperative transfusions, or the effect of transfusion on functional outcomes of spine surgery patients. Further research is warranted to address these clinical issues.

Direct Oral Anticoagulants in Patients Undergoing Spine Surgery

OBJECTIVE

Despite increasing use of direct oral anticoagulants (DOACs), guidelines for their perioperative use in spine surgery are still lacking. The main goal of our study was to analyze the occurrence of postoperative bleeding events and possible confounders in patients treated with DOACs who undergo spine surgery.

METHODS

Of 2777 patients undergoing spine surgery at our institution, 82 (2.9%) were treated with DOACs. The primary endpoint was postoperative bleeding events. Secondary outcome measures were postoperative thromboembolic events and anemia, hematologic findings, perioperative packed red blood cell substitution, operative time, hospital length of stay, morbidity, and mortality. Subanalysis of possible confounders affecting the rates of bleeding was also performed. Additionally, correlation of bleeding event rates and preoperative and postoperative discontinuation of DOACs was analyzed.

RESULTS

Overall postoperative bleeding events rate was 4.9% (n = 4). Preoperative DOAC discontinuation time of <24 hours increased significantly the rate of perioperative packed red blood cell substitution (P = 0.007). Treatment with concomitant blood thinners showed a trend toward higher incidence of bleeding events (P = 0.066), whereas pre-existing kidney failure increased significantly rates of postoperative anemia (P = 0.014). The rate of postoperative thromboembolic events was 4.9% (n = 4); all events occurred with DOAC resumption >72 hours postoperatively.

CONCLUSIONS

Short preoperative discontinuation time of DOACs, even <24 hours, may be justified, considering an increased risk of perioperative packed red blood cell substitution. Care should be taken with patients treated with concomitant blood thinners and patients with pre-existing kidney disease. Postoperative DOAC resumption >72 hours may increase risk of thromboembolic events.

Performance Indicators in Spine Surgery

STUDY DESIGN

Systematic review.

OBJECTIVE

To elucidate how performance indicators are currently used in spine surgery.

SUMMARY OF BACKGROUND DATA

The Patient Protection and Affordable Care Act has given significant traction to the idea that healthcare must provide value to the patient through the introduction of hospital value-based purchasing. The key to implementing this new paradigm is to measure this value notably through performance indicators.

METHODS

MEDLINE, CINAHL Plus, EMBASE, and Google Scholar were searched for studies reporting the use of performance indicators specific to spine surgery. We followed the Prisma-P methodology for a systematic review for entries from January 1980 to July 2016. All full text articles were then reviewed to identify any measure of performance published within the article. This measure was then examined as per the three criteria of established standard, exclusion/risk adjustment, and benchmarking to determine if it constituted a performance indicator.

RESULTS

The initial search yielded 85 results among which two relevant studies were identified. The extended search gave a total of 865 citations across databases among which 15 new articles were identified. The grey literature search provided five additional reports which in turn led to six additional articles. A total of 27 full text articles and reports were retrieved and reviewed. We were unable to identify performance indicators. The articles presenting a measure of performance were organized based on how many criteria they lacked. We further examined the next steps to be taken to craft the first performance indicator in spine surgery.

CONCLUSION

The science of performance measurement applied to spine surgery is still in its infancy. Current outcome metrics used in clinical settings require refinement to become performance indicators. Current registry work is providing the necessary foundation, but requires benchmarking to truly measure performance.

LEVEL OF EVIDENCE

1.

Feasibility of a Modified E-PASS and POSSUM System for Postoperative Risk Assessment in Patients with Spinal Disease

OBJECTIVE

This retrospective case control study aimed to evaluate the feasibility of using Estimation of Physiological Ability and Surgical Stress (E-PASS) and Physiological and Operative Severity Score for the enumeration of Mortality and Morbidity (POSSUM) systems in patients undergoing spinal surgical procedures. Degenerative spine disease has increased in incidence in aging societies, as has the number of older adult patients undergoing spinal surgery. Many older adults are at a high surgical risk because of comorbidity and poor general health.

METHODS

We retrospectively reviewed 217 patients who had undergone spinal surgery at a single tertiary care. We investigated complications within 1 month after surgery. Criteria for both skin incision in E-PASS and operation magnitude in the POSSUM system were modified to fit spine surgery. We calculated the E-PASS and POSSUM scores for enrolled patients, and investigated the relationship between postoperative complications and both surgical risk scoring systems. To reinforce the predictive ability of the E-PASS system, we adjusted equations and developed modified E-PASS systems.

RESULTS

The overall complication rate for spinal surgery was 22.6%. Forty-nine patients experienced 58 postoperative complications. Nineteen major complications, including hematoma, deep infection, pleural effusion, progression of weakness, pulmonary edema, esophageal injury, myocardial infarction, pneumonia, reoperation, renal failure, sepsis, and death, occurred in 17 patients. The area under the receiver operating characteristic curve (AUC) for predicted postoperative complications after spine surgery was 0.588 for E-PASS and 0.721 for POSSUM. For predicted major postoperative complications, the AUC increased to 0.619 for E-PASS and 0.842 for POSSUM. The AUC of the E-PASS system increased from 0.588 to 0.694 with the Modified E-PASS equation.

CONCLUSIONS

The POSSUM system may be more useful than the E-PASS system for estimating postoperative surgical risk in patients undergoing spine surgery. The preoperative risk scores of E-PASS and POSSUM can be useful for predicting postoperative major complications. To enhance the predictability of the scoring systems, using of modified equations based on spine surgery-specific factors may help ensure surgical outcomes and patient safety.

Risk factors for wound complications following spine surgery

Background

Wound complications, including surgical site infections (SSIs) and wound dehiscence, are among the most common complications following spine surgery often leading to readmission. The authors sought to identify preoperative characteristics predictive of wound complications after spine surgery.

Methods

The American College of Surgeons National Surgical Quality Improvement Program database for years 2012-2014 was reviewed for patients undergoing spine surgery, defined by the Current Procedural Terminology codes. Forty-four preoperative and surgical characteristics were analyzed for associations with wound complications.

Results

Of the 99,152 patients included in this study, 2.2% experienced at least one wound complication (superficial SSI: 0.9%, deep SSI: 0.8%, organ space SSI: 0.4%, and dehiscence: 0.3%). Multivariate binary logistic regression testing found 10 preoperative characteristics associated with wound complications: body mass index ≥30, smoker, female, chronic steroid use, hematocrit <38%, infected wound, inpatient status, emergency case, and operation time >3 hours. A risk score for each patient was created from the number of characteristics present. Receiver operating characteristic curves of the unweighted and weighted risk scores generated areas under the curve of 0.701 (95% CI: 0.690-0.713) and 0.715 (95% CI: 0.704-0.726), respectively. Patients with unweighted risk scores >7 were 25-fold more likely to develop a wound complication compared to patients with scores of 0. In addition, mortality rate, reoperation rate, and total length of stay each increased nearly 10-fold with increasing risk score.

Conclusion

This study introduces a novel risk score for the development of wound dehiscence and SSIs in patients undergoing spine surgery, using new risk factors identified here.

Mortality and morbidity after spinal surgery in patients with Parkinson's disease: a retrospective matched-pair cohort study

BACKGROUND CONTEXT

There is a lack of information about postoperative outcomes and related risk factors associated with spinal surgery in patients with Parkinson's disease (PD).

PURPOSE

This study aimed to investigate the postoperative morbidity and mortality associated with spinal surgery for patients with PD, and the risk factors for poor outcomes.

STUDY DESIGN

This is a retrospective matched-pair cohort study.

PATIENT SAMPLE

Data of patients who underwent elective spinal surgery between July 2010 and March 2013 were extracted from the Diagnosis Procedure Combination database, a nationwide inpatient database in Japan.

OUTCOME MEASURES

In-hospital mortality and occurrence of postoperative complications.

METHODS

For each patient with PD, we randomly selected up to four age- and sex-matched controls in the same hospital in the same year. The differences in in-hospital mortality and occurrence of postoperative complications were compared between patients with PD and controls. A multivariable logistic regression model fitted with a generalized estimation equation was used to identify significant predictors of major complications (surgical site infection, sepsis, pulmonary embolism, respiratory complications, cardiac events, stroke, and renal failure). Multiple imputation was used for missing data.

RESULTS

Among 154,278 patients undergoing spinal surgery, 1,423 patients with PD and 5,498 matched controls were identified. Crude in-hospital mortality was higher in patients with PD than in controls (0.8% vs. 0.3%, respectively). The crude proportion of major complications was also higher in patients with PD (9.8% vs. 5.1% in controls). Postoperative delirium was more common in patients with PD (30.3%) than in controls (4.3%). Parkinson's disease was a significant predictor of major postoperative complications, even after adjusting for other risk factors (odds ratio, 1.74; 95% confidence intervals, 1.37-2.22; p<.001).

CONCLUSIONS

Patients with PD had a significantly increased risk of postoperative complications following spinal surgery. Postoperative delirium was the most frequently observed complication.

National Database Research in Spine Surgery: Limitations in the Current Literature

Many of the studies in the spine surgical literature using national databases have been directed at examining adverse events, readmission rates, cost, and risk factors for poorer outcomes. Although such studies allow for assessment of large cohorts taken from multiple institutions, they are limited by data collection methods, short-term follow-up, and minimal assessment of functional outcomes. Furthermore, few studies are directed at producing actionable practice changes to improve patient care. Recent work aimed at producing databases with more relevance to spine surgery represent exciting developments to the rapidly growing field of health outcomes research.

Development of Validated Computer-based Preoperative Predictive Model for Proximal Junction Failure (PJF) or Clinically Significant PJK With 86% Accuracy Based on 510 ASD Patients With 2-year Follow-up

STUDY DESIGN

A retrospective review of large, multicenter adult spinal deformity (ASD) database.

OBJECTIVE

The aim of this study was to build a model based on baseline demographic, radiographic, and surgical factors that can predict clinically significant proximal junctional kyphosis (PJK) and proximal junctional failure (PJF).

SUMMARY OF BACKGROUND DATA

PJF and PJK are significant complications and it remains unclear what are the specific drivers behind the development of either. There exists no predictive model that could potentially aid in the clinical decision making for adult patients undergoing deformity correction.

METHODS

Inclusion criteria: age ≥18 years, ASD, at least four levels fused. Variables included in the model were demographics, primary/revision, use of three-column osteotomy, upper-most instrumented vertebra (UIV)/lower-most instrumented vertebra (LIV) levels and UIV implant type (screw, hooks), number of levels fused, and baseline sagittal radiographs [pelvic tilt (PT), pelvic incidence and lumbar lordosis (PI-LL), thoracic kyphosis (TK), and sagittal vertical axis (SVA)]. PJK was defined as an increase from baseline of proximal junctional angle ≥20° with concomitant deterioration of at least one SRS-Schwab sagittal modifier grade from 6 weeks postop. PJF was defined as requiring revision for PJK. An ensemble of decision trees were constructed using the C5.0 algorithm with five different bootstrapped models, and internally validated via a 70 : 30 data split for training and testing. Accuracy and the area under a receiver operator characteristic curve (AUC) were calculated.

RESULTS

Five hundred ten patients were included, with 357 for model training and 153 as testing targets (PJF: 37, PJK: 102). The overall model accuracy was 86.3% with an AUC of 0.89 indicating a good model fit. The seven strongest (importance ≥0.95) predictors were age, LIV, pre-operative SVA, UIV implant type, UIV, pre-operative PT, and pre-operative PI-LL.

CONCLUSION

A successful model (86% accuracy, 0.89 AUC) was built predicting either PJF or clinically significant PJK. This model can set the groundwork for preop point of care decision making, risk stratification, and need for prophylactic strategies for patients undergoing ASD surgery.

LEVEL OF EVIDENCE

3.

Systemic inaccuracies in the National Surgical Quality Improvement Program database: Implications for accuracy and validity for neurosurgery outcomes research

The American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) provides a rich database of North American surgical procedures and their complications. Yet no external source has validated the accuracy of the information within this database. Using records from the 2006 to 2013 NSQIP database, we used two methods to identify errors: (1) mismatches between the Current Procedural Terminology (CPT) code that was used to identify the surgical procedure, and the International Classification of Diseases (ICD-9) post-operative diagnosis: i.e., a diagnosis that is incompatible with a certain procedure. (2) Primary anesthetic and CPT code mismatching: i.e., anesthesia not indicated for a particular procedure. Analyzing data for movement disorders, epilepsy, and tumor resection, we found evidence of CPT code and postoperative diagnosis mismatches in 0.4-100% of cases, depending on the CPT code examined. When analyzing anesthetic data from brain tumor, epilepsy, trauma, and spine surgery, we found evidence of miscoded anesthesia in 0.1-0.8% of cases. National databases like NSQIP are an important tool for quality improvement. Yet all databases are subject to errors, and measures of internal consistency show that errors affect up to 100% of case records for certain procedures in NSQIP. Steps should be taken to improve data collection on the frontend of NSQIP, and also to ensure that future studies with NSQIP take steps to exclude erroneous cases from analysis.