Risk Factors for 30- and 90-Day Readmission due to Intestinal Bowel Obstruction after Posterior Lumbar Fusion.

STUDY DESIGN: A retrospective analysis of data from the Healthcare Cost and Utilization Project Nationwide Readmissions Database (HCUP-NRD). PURPOSE: To identify the perioperative characteristics associated with 30-day and 90-day readmission due to intestinal bowel obstructions (IBOs) following posterior lumbar fusion (PLF) procedure. OVERVIEW OF LITERATURE: PLF procedures are used to repair spinal injuries and curvature deformities. IBO is a common surgical complication and its repair often necessitates surgery that increases the readmission rates and healthcare costs. Previous studies have identified the preoperative risk factors for 30-day readmissions in PLF; however, no study has specifically investigated IBO or identified risk factors for 90-day readmissions. METHODS: Data on demographic characteristics and medical comorbidities of patients who underwent PLF with subsequent readmission were obtained from the HCUP-NRD. The perioperative characteristics that were significantly different between patients readmitted with and without an active diagnosis of IBO were identified with bivariate analysis for both 30-day and 90-day readmissions. The significant characteristics were then included in a multivariate analysis to identify those that were independently associated with 30- day and 90-day readmissions. RESULTS: Drug abuse (odds ratio [OR], 4.00), uncomplicated diabetes (OR, 2.06), having Medicare insurance (OR, 1.65), age 55-64 years (OR, 2.42), age 65-79 years (OR, 2.77), and age >80 years (OR, 3.87) were significant risk factors for 30-day readmission attributable to IBO after a PLF procedure. CONCLUSIONS: Of the several preoperative risk factors identified for readmission with IBO after PLF surgery, drug abuse had the strongest association and was likely to be the most clinically relevant factor. Physicians and care teams should understand the risks of opioid-based pain management regimens, attempt to manage pain with a multimodal approach, and minimize the opioid use.

Age-related Changes in Cervical Sagittal Alignment: A Radiographic Analysis.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To identify age-related changes in cervical sagittal parameters using standard radiographs. SUMMARY OF BACKGROUND DATA: Cervical sagittal balance is important for the maintenance of neutral head posture and horizontal gaze. Degenerative changes in the cervical spine that occur with aging may alter cervical sagittal balance, which can lead to chronic neck pain and predispose to various cervical spine pathologies. METHODS: We performed a retrospective cohort study of 151 patients with lateral cervical spine radiographs taken at our institution between December 2017 and June 2018. Cervical sagittal parameters were measured, including C1 inclination, C2 slope, C2-C7 Cobb angle, cervical sagittal vertical axis (cSVA), cervical tilt, upper and lower C7 slopes, T1 slope, and T1 slope minus cervical lordosis (TS-CL). The association between age and cervical sagittal parameters was assessed using the Pearson correlation coefficient and a linear regression analysis. An analysis of variance (ANOVA) with Tukey adjustments was then performed to identify differences in cervical sagittal parameters among patients aged 18 to 39 years, 40 to 64 years, and >64 years of age. RESULTS: There were positive correlations between age and C2-C7 Cobb angle (r = 0.231, P = 0.004), upper C7 slope (r = 0.280, P < 0.001), lower C7 slope (r = 0.283, P < 0.001), and T1 slope (r = 0.189, P = 0.020). Upper C7 slope (R = 0.079) and lower C7 slope (R = 0.074) had the strongest correlation with age in the linear regression analysis. The ANOVA found significant differences among the age subgroups in terms of C2-C7 Cobb angle (P = 0.002), upper C7 slope (P < 0.001), lower C7 slope (P < 0.001), and T1 slope (P = 0.031). Patients >64 years old had significantly higher C2-C7 Cobb angle, upper C7 slope, lower C7 slope, and T1 slope. CONCLUSION: Changes in cervical sagittal alignment with age are characterized by increased cervical lordosis and increased thoracic kyphosis. LEVEL OF EVIDENCE: 3.

The Effects of Preoperative Steroid Therapy on Perioperative Complications After Elective Anterior Lumbar Fusion.

OBJECTIVE: To examine the effects of chronic preoperative steroid therapy on 30-day perioperative complications after anterior lumbar fusion (ALF). METHODS: We retrospectively analyzed data from the American College of Surgeons National Surgical Quality Improvement Program between 2008 and 2015. Adult patients who underwent ALF were included and divided into 2 groups: steroids and no steroids. We compared baseline patient demographics, comorbidities, and operative variables between these 2 groups and then performed a multivariate regression analysis to determine complications that were independently associated with chronic steroid therapy. We also performed a subgroup analysis of the steroid group to identify additional risk factors that further predispose these patients to postoperative complications. RESULTS: A total of 9483 patients were included, of whom 289 (3.0%) were on chronic steroid therapy. Univariate analysis showed that chronic steroid use was independently associated with 4 perioperative complications, including deep surgical site infection (odds ratio [OR], 2.78; confidence interval [CI], 1.09-7.10; P = 0.033), pulmonary complications (OR, 1.98; CI, 1.02-3.86; P = 0.044), blood transfusion (OR, 1.60; CI, 1.15-2.23; P = 0.005), and extended length of stay (OR, 1.58; CI, 1.17-2.16; P = 0.003). In patients on chronic steroid therapy, pulmonary comorbidity and extended operative time were additional risk factors that further predisposed to perioperative complications, including deep surgical site infection, blood transfusion, and extended length of stay. CONCLUSIONS: Chronic preoperative steroid therapy is associated with perioperative complications after ALF. Decisions about the discontinuing or holding steroid therapy preoperatively should be determined through an interdisciplinary approach between the medical and surgical teams.

Risk Factors Associated with 30-Day Mortality After Open Reduction and Internal Fixation of Vertebral Fractures.

OBJECTIVE: Few studies have examined the outcomes of open reduction and internal fixation of vertebral fractures. The purpose of this study was to determine patient-related and surgery-related risk factors associated with 30-day postoperative mortality after open reduction and internal fixation (ORIF) of cervical, thoracic, and lumbar vertebral fractures. METHODS: This was a retrospective cohort study of data from the 2010-2014 ACS-NSQIP database. Adult patients who underwent ORIF of vertebral fractures in the cervical, thoracic, or lumbar spine were included. Patients were divided into 2 groups on the basis of the occurrence of 30-day postoperative mortality. A univariate analysis was performed to compare baseline patient characteristics, comorbidities, operative variables, and 30-day postoperative complications between the mortality and nonmortality groups. A subsequent multivariate regression analysis adjusting for patient and operative factors was then performed to identify independent risk factors for 30-day mortality. RESULTS: A total of 900 patients who underwent vertebral ORIF were included. The overall 30-day postoperative mortality rate was 1.56%. The mortality group had a higher incidence of pneumonia, pulmonary complications, cardiac complications, blood transfusion, sepsis, and prolonged hospitalization. Multivariate regression analysis identified pulmonary comorbidity and diabetes as independent predictors of 30-day mortality following ORIF of vertebral fractures. CONCLUSIONS: Pulmonary comorbidity and diabetes were found to be independent risk factors for 30-day mortality after ORIF of vertebral fractures. Recognizing these risk factors is important in preoperative risk stratification, perioperative care, and patient counseling.

Predictors of Discharge Disposition Following Laminectomy for Intradural Extramedullary Spinal Tumors.

OBJECTIVE: To identify independent risk factors for non-home discharge in patients undergoing laminectomy for intradural extramedullary spinal tumors. METHODS: We performed a retrospective cohort analysis of data from the American College of Surgeons National Surgical Quality Improvement Program from 2011 to 2014. Adult patients who underwent laminectomy for the excision of intradural extramedullary spinal tumors were included and divided into 2 groups based on home or non-home discharge disposition. We compared baseline patient characteristics, comorbidities, and operative factors between the 2 groups, and then performed multivariate regression analyses to identify independent risk factors for non-home discharge. RESULTS: A total of 1232 patients were included, of whom 248 (20.1%) were discharged to a non-home facility. Univariate analysis demonstrated that patients discharged to a non-home facility were more frequently aged ≥65 years and American Society of Anesthesiologists classification ≥3 with obesity, diabetes, dyspnea, functional dependence, cardiac comorbidity, renal comorbidity, and anemia. Operative factors correlated with non-home discharge were operative time of ≥4 hours and tumor location in the cervical or thoracic spine. Multivariate regression analysis identified age ≥65 years (odds ratio [OR] 2.73; confidence interval [CI] 1.80-4.13; P < 0.001), American Society of Anesthesiologists classification ≥3 (OR 2.36; CI 1.53-3.65; P < 0.001), dependent functional status (OR 4.30; CI 1.95-9.48; P < 0.001), hospital-acquired conditions (OR 2.32; CI 1.15-4.68; P = 0.019), and prolonged length of stay (OR 4.05; CI 2.72-6.03; P < 0.001) as predictors of non-home discharge. CONCLUSIONS: Early identification of patients at risk for non-home discharge is important in order to implement comprehensive discharge planning protocols that reduce inpatient length of stay, as well as associated complications and costs.

Role of Posterior Ligamentous Reinforcement in Proximal Junctional Kyphosis: A Cadaveric Biomechanical Study.

STUDY DESIGN: Cadaveric biomechanical study. PURPOSE: The purpose of this study was to biomechanically evaluate the effect of preserving or augmenting the interspinous ligament (ISL) and supraspinous ligament (SSL; ISL/SSL) complex between the upper instrumented vertebra (UIV) and UIV+1 using a cadaveric model. OVERVIEW OF LITERATURE: Adult spinal deformity is becoming an increasingly prevalent disorder, and proximal junctional kyphosis (PJK) is a well-known postoperative complication following long spinal fusion. METHODS: Pure moments of 4 and 8 Nm were applied to the native and instrumented spine, respectively (n=8). The test conditions included the following: native spine (T7-L2), fused spine (T10-L2), fused spine with a hand-tied suture loop through the spinous processes at T9-T10, and fused spine with severed T9-T10 ISL/SSL complex. RESULTS: The flexion range of motion (ROM) at T9-T10 of the fused spine loaded at 8 Nm increased by 62% compared to that of the native spine loaded at 4 Nm. The average flexion ROM at T9-T10 for the suture loop and severed ISL/SSL spines were 141% (p=0.13) and 177% (p=0.66) of the native spine at 4 Nm, respectively (p-values vs. fused). CONCLUSIONS: Transection of the ISL/SSL complex did not significantly change flexion ROM at the proximal junctional segment following instrumented spinal fusion. Furthermore, augmentation of the posterior ligamentous tension band with a polyester fiber suture loop did not mitigate excessive flexion loads on the proximal junctional segment. We postulate that the role of the posterior ligamentous tension band in mitigating PJK is secondary to the anterior column support provided by the vertebral body and intervertebral disc.

Outcomes and Complications Following Laminectomy Alone for Thoracic Myelopathy due to Ossified Ligamentum Flavum: A Systematic Review and Meta-Analysis.

STUDY DESIGN: Systematic review and meta-analysis. OBJECTIVE: Examine the functional outcomes and complications following laminectomy for thoracic myelopathy due to ossification of the ligamentum flavum (OLF). SUMMARY OF BACKGROUND DATA: OLF is a rare condition that can cause thoracic myelopathy. Laminectomy is a procedure that can be performed to decompress the spinal cord in patients with thoracic myelopathy due to OLF. Few studies have examined postoperative outcomes and complications following laminectomy for thoracic myelopathy secondary to OLF. METHODS: A systematic review and meta-analysis was performed. Literature search yielded six studies that met our selection criteria. Study characteristics and baseline patient demographics were extracted from each study. Primary outcomes included pre- and postoperative Japanese Orthopedic Association (JOA) scores and perioperative complications including dural tears, cerebrospinal fluid (CSF) leaks, neurological deficits, surgical site infections, and other complications. We calculated pooled proportion estimates for JOA scores and complications using a random effects model. RESULTS: A total of 137 patients were included. The pooled pre- and postoperative JOA scores were 5.08 (95% confidence interval [CI], 2.70-7.47; I = 98%) and 8.29 (95% CI, 7.73-8.85; I = 18%), respectively, with a mean improvement of +3.03 points (95% CI, 1.08-4.98; I = 88%). Pooled proportion estimates for dural tears, CSF leaks, infections, and early neurological deficits were 18.4% (95% CI, 12.6-26.1; I = 0%), 12.1% (95% CI, 6.6-21.2; I = 0%), 5.8% (95% CI, 2.1-15.4; I = 0%), and 5.7% (95% CI, 2.2-14.3; I = 0%), respectively. CONCLUSION: Thoracic myelopathy secondary to OLF can be treated with laminectomy. However, despite some improvement in JOA score, functional status remains poor postoperatively. Perioperative complications are common, with dural tears and CSF leaks occurring most frequently. OLF is an uncommon condition and more research is needed to better understand how we can improve the outcomes of laminectomy alone for the treatment of thoracic myelopathy due to OLF. LEVEL OF EVIDENCE: 3.

The Seven-Year Cost-Effectiveness of Anterior Cervical Discectomy and Fusion Versus Cervical Disc Arthroplasty: A Markov Analysis.

STUDY DESIGN: Markov model analysis. OBJECTIVE: The aim of this study was to determine the 7-year cost-effectiveness of single-level anterior cervical discectomy and fusion (ACDF) versus cervical disc replacement (CDR) for the treatment of cervical disc degeneration. SUMMARY OF BACKGROUND DATA: Both ACDF and CDR are acceptable surgical options for the treatment of symptomatic cervical disc degeneration. Past studies have demonstrated at least equal effectiveness of CDR when compared with ACDF in large randomized Investigational Device Exemption (IDE) studies. Short-term cost-effectiveness analyses at 5 years have suggested that CDR may be the preferred treatment option. However, adjacent segment disease and other postoperative complications may occur after 5 years following surgery. METHODS: A Markov model analysis was used to evaluate data from the LDR Mobi-C IDE study, incorporating five Markov transition states and seven cycles with each cycle set to a length of 1 year. Transition state probabilities were determined from complication rates, as well as index and adjacent segment reoperation rates from the IDE study. Raw SF-12 data were converted to health state utility values using the SF-6D algorithm for 174 CDR patients and 79 ACDF patients. RESULTS: Assuming an ideal operative candidate who is 40-years-old and failed appropriate conservative care, the 7-year cost was $103,924 for ACDF and $105,637 for CDR. CDR resulted in the generation of 5.33 quality-adjusted life-years (QALYs), while ACDF generated 5.16 QALYs. Both ACDF and CDR were cost-effective, but the incremental cost-effectiveness ratio (ICER) was $10,076/QALY in favor of CDR, which was less than the willingness-to-pay (WTP) threshold of $50,000/QALY. CONCLUSION: ACDF and CDR are both cost-effective strategies for the treatment of cervical disc degeneration. However, CDR is the more cost-effective procedure at 7 years following surgery. Further long-term studies are needed to validate the findings of this model. LEVEL OF EVIDENCE: 1.

The Impact of Metastatic Spinal Tumor Location on 30-Day Perioperative Mortality and Morbidity After Surgical Decompression.

STUDY DESIGN: A retrospective cohort study from 2011 to 2014 was performed using the American College of Surgeons National Surgical Quality Improvement Program database. OBJECTIVE: The purpose of this study was to assess the impact of tumor location in the cervical, thoracic, or lumbosacral spine on 30-day perioperative mortality and morbidity after surgical decompression of metastatic extradural spinal tumors. SUMMARY OF BACKGROUND DATA: Operative treatment of metastatic spinal tumors involves extensive procedures that are associated with significant complication rates and healthcare costs. Past studies have examined various risk factors for poor clinical outcomes after surgical decompression procedures for spinal tumors, but few studies have specifically investigated the impact of tumor location on perioperative mortality and morbidity. METHODS: We identified 2238 patients in the American College of Surgeons National Surgical Quality Improvement Program database who underwent laminectomy for excision of metastatic extradural tumors in the cervical, thoracic, or lumbosacral spine. Baseline patient characteristics were collected from the database. Univariate and multivariate regression analyses were performed to examine the association between spinal tumor location and 30-day perioperative mortality and morbidity. RESULTS: On univariate analysis, cervical spinal tumors were associated with the highest rate of pulmonary complications. Multivariate regression analysis demonstrated that cervical spinal tumors had the highest odds of multiple perioperative complications. However, thoracic spinal tumors were associated with the highest risk of intra- or postoperative blood transfusion. In contrast, patients with metastatic tumors in the lumbosacral spine had lower odds of perioperative mortality, pulmonary complications, and sepsis. CONCLUSION: Tumor location is an independent risk factor for perioperative mortality and morbidity after surgical decompression of metastatic spinal tumors. The addition of tumor location to existing prognostic scoring systems may help to improve their predictive accuracy. LEVEL OF EVIDENCE: 3.

Reoperations Following Cervical Disc Replacement.

Cervical disc replacement (CDR) has emerged as an alternative surgical option to cervical arthrodesis. With increasing numbers of patients and longer follow-ups, complications related to the device and/or aging spine are growing, leaving us with a new challenge in the management and surgical revision of CDR. The purpose of this study is to review the current literature regarding reoperations following CDR and to discuss about the approaches and solutions for the current and future potential complications associated with CDR. The published rates of reoperation (mean, 1.0%; range, 0%-3.1%), revision (mean, 0.2%; range, 0%-0.5%), and removal (mean, 1.2%; range, 0%-1.9%) following CDR are low and comparable to the published rates of reoperation (mean, 1.7%; range; 0%-3.4%), revision (mean, 1.5%; range, 0%-4.7%), and removal (mean, 2.0%; range, 0%-3.4%) following cervical arthrodesis. The surgical interventions following CDR range from the repositioning to explantation followed by fusion or the reimplantation to posterior foraminotomy or fusion. Strict patient selection, careful preoperative radiographic review and surgical planning, as well as surgical technique may reduce adverse events and the need for future intervention. Minimal literature and no guidelines exist for the approaches and techniques in revision and for the removal of implants following CDR. Adherence to strict indications and precise surgical technique may reduce the number of reoperations, revisions, and removals following CDR. Long-term follow-up studies are needed, assessing the implant survivorship and its effect on the revision and removal rates.