Anuj Singla

Morbid Obesity and Lumbar Fusion in Patients Older Than 65 Years: Complications, Readmissions, Costs, and Length of Stay

Study Design. Retrospective database review. Objective. The aim of this study was to determine how both morbid obesity (body mass index [BMI] ≥40) and obesity (BMI 30–39.9) modify 90-day complication rates and 30-day readmission rates following 1- to 2-level, primary, lumbar spinal fusion surgery for degenerative pathology in an elderly population. Summary of Background Data. In the United States, both obese and elderly patients are known to have increased risk of complication, yet both demographics are increasingly undergoing elective lumbar spine surgery. Methods. Medicare data from 2005 to 2012 were queried for patients who underwent primary 1- to 2-level posterolateral lumbar fusion for degenerative pathology. Elderly patients undergoing elective surgery were selected and separated into three cohorts: morbidly obese (BMI ≥40; n = 2594), obese (BMI ≥30, < 40] (n = 5534), and nonobese controls (n = 48,210). Each pathologic cohort was matched to a unique subcohort from the control population. Ninety-day medical and surgical complication rates, 30-day readmission rates, length of stay (LOS), and hospital costs were then compared. Results. Both morbidly obese and obese patients had significantly higher odds of experiencing any one major medical complication (odds ratio [OR] 1.79; P < 0.0001 and OR 1.32; P < 0.0001, respectively). Wound infection (OR 3.71; P < 0.0001 and OR 2.22; P < 0.0001) and dehiscence (OR 3.80; P < 0.0001 and OR 2.59; P < 0.0001) rates were increased in morbidly obese and obese patients, respectively. Thirty-day readmissions, length of stay, and in-hospital costs were increased, with patients with morbid obesity incurring charges almost

Preoperative epidural injections are associated with increased risk of infection after single-level lumbar decompression.

8000 greater than controls. Conclusion. Patients with both obesity and morbid obesity are at significantly increased risk of major medical complications, wound complications, and 30-day readmissions. Additionally, both groups of patients have significantly increased LOS and hospital costs. Both obese and morbidly obese patients should be appropriately counseled of these risks and must be carefully selected to reduce postoperative morbidity. Level of Evidence: 3

Biomechanics of Degenerative Spinal Disorders

BACKGROUND CONTEXT Lumbar epidural steroid injections (LESIs) are often performed as a treatment option for lumbar stenosis and radiculopathy before lumbar decompression surgery. Several case series have reported spinal infections after LESIs. There is lack of literature on the rate of postoperative infections after lumbar decompression in patients who had prior LESIs. PURPOSE The goal of the present study is to employ a large national database to determine if there is an association between preoperative LESIs at various time intervals before lumbar decompression and the incidence of postoperative infection. STUDY DESIGN/SETTING Retrospective case control database study, Level III was used in this study. PATIENT SAMPLE This study comprised Medicare patients over age 65 years who had a LESI within 1 year of single-level lumbar decompression surgery. OUTCOME MEASURES International Classification of Diseases, 9th Revision diagnosis codes for postoperative infection and Current Procedural Terminology procedure codes for treatment of postoperative infection were the outcome measures for this study. METHODS The PearlDiver Patient Records Database, an insurance-based database of patient records, was used for this study. The database was queried for LESI and single-level lumbar decompression procedures using Current Procedural Terminology codes. These study patients were then divided into four separate cohorts: (1) lumbar decompression within 1 month following LESI, (2) lumbar decompression between 1 and 3 months following LESI, (3) lumbar decompression between 3 and 6 months following LESI, and (4) lumbar decompression between 6 and 12 months following LESI. Unique control groups for each study cohort were created with patients who underwent single-level lumbar decompression without previous LESI and matched for major risk factors for infection, including age, gender, smoking status, diabetes, and obesity. RESULTS Overall, the rate of postoperative infection after single-level lumbar decompression after LESI remained relatively low, ranging between 0.8% and 1.7%. The incidence of 90-day postoperative infection after lumbar decompression was significantly higher than matched controls in groups with LESI within 1 month (OR=3.2, p<.0001) and 1-3 months before surgery (OR=1.8, p<.0001). The incidence of 90-day postoperative infection was not significantly different from matched controls in groups with LESI between 3-6 months (OR=1.3, p=.15) and 6-12 months before decompression surgery (OR=1.3, p=.18) CONCLUSIONS: Single-level lumbar decompression within 3 months after LESI may be associated with an increased rate of postoperative infection. Increasing the time interval between LESI and single-level lumbar decompression surgery to at least 3 months may decrease postoperative infection rates.

Readmission Rates, Reasons, and Risk Factors in Elderly Patients Treated With Lumbar Fusion for Degenerative Pathology

The spine has several important functions including load transmission, permission of limited motion, and protection of the spinal cord. The vertebrae form functional spinal units, which represent the smallest segment that has characteristics of the entire spinal column. Discs and paired facet joints within each functional unit form a three-joint complex between which loads are transmitted. Surrounding the spinal motion segment are ligaments, composed of elastin and collagen, and joint capsules which restrict motion to within normal limits. Ligaments have variable strengths and act via different lever arm lengths to contribute to spinal stability. As a consequence of the longer moment arm from the spinous process to the instantaneous axis of rotation, inherently weaker ligaments (interspinous and supraspinous) are able to provide resistance to excessive flexion. Degenerative processes of the spine are a normal result of aging and occur on a spectrum. During the second decade of life, the intervertebral disc demonstrates histologic evidence of nucleus pulposus degradation caused by reduced end plate blood supply. As disc height decreases, the functional unit is capable of an increased range of axial rotation which subjects the posterior facet capsules to greater mechanical loads. A concurrent change in load transmission across the end plates and translation of the instantaneous axis of rotation further increase the degenerative processes at adjacent structures. The behavior of the functional unit is impacted by these processes and is reflected by changes in the stress-strain relationship. Back pain and other clinical symptoms may occur as a result of the biomechanical alterations of degeneration.

The Effect of Local Intraoperative Steroid Administration on the Rate of Postoperative Dysphagia Following ACDF: A Study of 245,754 Patients.

Study Design. Retrospective database review. Objective. To determine readmission rates after 1 to 2 level, primary, elective lumbar spinal fusion surgery for degenerative pathology and elucidate risk factors that predict increased risk of 30-day readmission Summary of Background Data. Early postoperative readmissions after spine surgery represent a significant source of increased cost and morbidity. As the elderly population represents a demographic with a growing need for spine surgery, readmissions within this population are of significant interest. Methods. Medicare data (2005–2012) from an insurance database was queried for patients who underwent primary 1 to 2 level posterolateral lumbar spine fusion surgeries for degenerative lumbar pathology. After applying specific exclusion criteria to select for elderly patients (65–84 yr) undergoing mostly elective procedures, 52,567 patients formed the final study population. Readmission rates for medical, surgical, and all reasons were calculated within 30 days, 90 days, and 1 year postoperatively. Risk factors for medical, surgical, and all 30-day readmissions were also determined. Results. Within 30 days, 90 days, and 1 year, 1510 (2.9%), 2776 (5.3%), and 6574 (12.5%) patients were readmitted, respectively. At 30 days, surgical diagnoses constituted 50.1% of all readmissions. Wound infection was the reason for readmission in 25.8% of all readmissions within 30 days. Diagnoses of chronic pulmonary disease (OR 1.41 95% CI 1.22–1.63), obesity (OR 2.20 95% CI 1.90–2.54), and positive smoking history (OR 1.33 95% CI 1.15–1.54) were associated with increased risk of surgical readmission. Conclusion. Elderly patients undergoing lumbar spine fusion experience 30-day, 90-day, and 1-year readmission rates of 2.9, 5.3, and 12.5% for both medical and surgical reasons. Surgical site infection and wound complications are the most common surgery-related reasons for readmission. Medical diagnoses are more predominant during later readmissions, highlighting the comorbidity burden present in elderly patients. Level of Evidence: 4

Results of selective thoracic versus nonselective fusion in Lenke type 3 curves.

Study Design. A retrospective database analysis. Objective. The aim of this study is to compare rates of postoperative dysphagia, length of stay, infection, and wound complications following short and long anterior cervical discectomy and fusion (ACDF) in patients who received local intraoperative steroids and those who did not. Summary of Background Data. Only one prior small institutional study has investigated the application of local steroids at the time of ACDF to decrease postoperative dysphagia. Methods. A large administrative database was utilized to compare rates of postoperative dysphagia, length of stay, and infectious complications within 90 days in patients who received local steroid following short (1–2 level) and long (3 or more level) ACDF and control groups who did not. Nonobtainable information within the database included type of steroid, application technique, outcome data, and incidence of miscoding and noncoding by physicians. Odds ratios (ORs), 95% confidence intervals (95% CIs) and P values were then calculated using SPSS. Results. The incidence of dysphagia was significantly lower (9.0% vs. 14.6%, P = 0.005) in patients who received local steroid in the long ACDF group (n = 322) than a control group who did not (n = 45,432). This was not observed (P = 0.198) in the short ACDF group who received steroid (n = 1770) compared with a control group who did not (n = 198,230). The mean difference in length of stay was 1 day less for patients who received local steroid in both the short and long ACDF groups (P < 0.0001). The combined rate of postoperative infection and wound complications was not significantly different between steroid and control groups (P = 0.717). Conclusion. This analysis of a large administrative database suggests that local intraoperative steroid is associated with a significantly reduced rate of postoperative dysphagia after long ACDF and reduced average length of stay following both long and short ACDF without any increase in the rate of postoperative infection or wound complication. Level of Evidence: 3

Complications and Mortality Following 1 to 2 Level Lumbar Fusion Surgery in Patients Above 80 Years of Age.

Study Design. A retrospective analysis of a prospectively collected multicenter database. Objective. To identify the radiographical and clinical outcomes in Lenke 3 curves fused selectively (S) versus nonselectively (NS). Summary of Background Data. Surgical treatment options for Lenke 3 curves include fusion of both curves (NS) or selective thoracic curve fusion (S). Selective fusion of the thoracic curve spares lumbar motion segments; however, it may result in marked residual deformity. Methods. A prospectively collected multicenter database was retrospectively reviewed for adolescent idiopathic scoliosis Lenke 3 curves treated with posterior spinal fusion with a minimum of 2 years of follow-up. Patients were divided into 2 groups: NS (nonselective fusion) and S (selective thoracic fusion). Radiographical and clinical data were compared between the groups using the unpaired Student t test and analysis of variance. Results. A total of 74 patients met our inclusion criteria, with 49 (66.2%) in the NS group and 25 (33.8%) in the S group. Overall, both groups were similar preoperatively except for lumbar Cobb (NS = 56.3°, S = 47.2°, P < 0.001), lumbar lordosis (NS = 56.9°, S = 67.2°, P = 0.001), lumbar rotational prominence (NS = 11.2°, S = 8.2°, P < 0.05), and lumbar apical translation (NS = 3.2 cm, S = 1.9 cm, P < 0.05). Postoperatively, NS fusion demonstrated significantly less coronal imbalance of 2 cm or less (NS = 10.2%, S = 56.0%, P < 0.001), better lumbar curve correction (NS = 68.2%, S = 51.9%, P < 0.001), better lumbar apical translation correction (NS = 1.2 cm, S = 2.1 cm, P < 0.01), and better percent correction of the lumbar prominence (NS = 66.5%, S = 40.4%, P < 0.05). Scoliosis Research Society Questionnaire 22 scores at 2 years were similar between the groups. Conclusion. Despite preoperatively smaller lumbar curves with less apical translation and lumbar prominence, most patients with selective fusions were out of balance postoperatively and had inferior radiographical outcomes as compared with their nonselective comparison cohort with similar patient-reported outcomes. Long-term follow-up is required to determine whether the trade-off of sparing motion segments at the expense of somewhat lessened radiographical outcomes is worthwhile. Level of Evidence: 2

Readmission Rates, Reasons, and Risk Factors Following Anterior Cervical Fusion for Cervical Spondylosis in Patients Above 65 Years of Age.

Study Design. Retrospective database review. Objective. To determine the 90-day complication rate and 90-day and 1-year mortality in patients 80 years of age and older who were treated with posterolateral lumbar spinal fusion surgery and to compare these rates against those of elderly patients ages 65 to 79. Summary of Background Data. Patients over 80 years of age specifically represent a substantial proportion of the US population, with over 11 million such individuals in 2010. Few studies have comprehensively assessed the morbidity associated with spinal fusion surgery in patients older than 80 years. Methods. The PearlDiver database (2005–2012) was utilized to determine morbidity and mortality rates after posterolateral lumbar or lumbosacral spinal fusion surgery of 2–3 vertebrae. Patients 65 to 79 (72,547) and ≥80-year old (12,187) were selected. Charlson comorbidity index scores were analyzed and compared, as were various comorbid conditions 90-day complication rates and mortality at 90-days and 1 year compared between cohorts. Results. The ≥80 year cohort had a higher average Charlson Comorbidity Index score than the 65 to 79 year cohort (7.99 vs. 6.54, P <0.0001). The proportion of patients experiencing at least one major complication was relatively increased by 45.6% in patients ≥80 year (13.87 vs. 9.52%; OR 1.53 95% CI 1.44 – 1.62 P <0.0001). Ninety-day (0.30 vs. 0.09%; OR: 3.50, 95% confidence interval: 2.33–5.26, P <0.0001) and 1-year (0.48 vs. 0.18%; OR: 2.58, 95% confidence interval: 1.90–3.52, P <0.0001) mortality were significantly higher in the ≥80 year cohort compared with the 65 to 79-year-old control group. Conclusion. Patients 80 years of age or older have significantly greater rates of major medical complication and mortality following 1 to 2 level lumbar spinal posterolateral fusion surgery compared with patients 65 to 79 years of age. Level of Evidence: 3

Complication and Reoperation Rates Following Surgical Management of Cervical Spondylotic Myelopathy in Medicare Beneficiaries.

Study Design. A retrospective database review. Objective. The aim of this study was to determine readmission reasons and rates following primary, elective anterior cervical spinal fusion surgery for cervical spondylosis and determine risk factors predicting increased risk of 30-day readmission in an exclusively elderly population. Summary of Background Data. In the United States, there were almost 190,000 cervical spine procedures in 2009. Many cervical spine surgery patients are elderly, a demographic increasingly requiring surgery for degenerative cervical spine pathology. Unfortunately, this patient population is poorly studied, particularly concerning readmission rates. Methods. Medicare data from 2005 to 2012 were queried for elderly patients (65–84 years) who underwent primary one to two and ≥three-level anterior cervical spine fusion surgeries for cervical spondylosis. Forty-five thousand two hundred eighty-four patients treated with one to two-level and 12,103 patients with ≥three-level anterior cervical fusion (ACF) were identified and included in two study cohorts. Reasons for and rates of readmission were determined within 30 days, 90 days, and one-year postoperatively. Risk factors for medical, surgical, and all 30-day readmissions were also determined, selecting from various comorbidities, demographics, and surgical variables. Results. Readmission rates of 1.0% to 1.4%, 2.7% to 3.6%, and 13.2% to 14.1% were observed within 30 days, 90 days, and one year. Within 30 days, over 30% of patients from both study cohorts were readmitted for surgical reasons. Of surgical reasons for 30-day readmission, hematoma/seroma diagnoses were the most frequent (11.4%–15.4% of all readmissions). Male gender, diabetes mellitus, chronic pulmonary disease, obesity, and smoking history were all found to be predictive of all-cause readmissions. Conclusion. Unplanned 30-day readmission rates following primary, elective ACF in elderly patients is low and often due to medical reasons. Frequent surgical reasons for 30-day readmission include hematoma/seroma formation. Male gender and various comorbid diagnoses are significant predictors of all-cause readmissions within 30 days. Level of Evidence: 3

The impact of preoperative epidural injections on postoperative infection in lumbar fusion surgery

Study Design. Retrospective database review. Objective. To compare complication and reoperation rates after anterior cervical discectomy and fusion (ACDF), posterior cervical fusion (PCFs), and anterior cervical corpectomy and fusion (ACCF) for cervical spondylotic myelopathy (CSM) using a large national database of Medicare beneficiaries. Summary of Background Data. CSM is the most common cause of myelopathy in patients over 55 years and is considered the most common cause of spinal cord dysfunction in the world. Surgical treatment includes ACDF, PCF, or ACCF procedures. Methods. The PearlDiver database (2005–2012) was utilized to determine revision rates after surgical treatment of CSM by one of the aforementioned surgical treatments. Specifically, 1 to 2 level ACDF, ACCF, and PCF and 3+ level PCF cohorts were included. Each cohort was stratified by the age of 65 years. Survivorship curves were graphed and compared. Results. Of the patients younger than 65 years of age, there were 10,557 patients treated with 1 to 2 level ACDF procedures, 1319 patients with 1 to 2 level PCF procedures, 1203 patients with 1 to 2 level ACCF procedures, and 2312 patients treated with 3+ level PCF procedures. Of the elderly patients, 24,310 patients were treated with 1 to 2 level ACDFs, 4776 with 1 to 2 level PCF procedures, 3109 with 1 to 2 level ACCFs, and 7760 with 3+ level PCFs. Patients younger than 65 years of age were significantly more likely to have a reoperation procedure, than those 65 years or older when analyzing ACCF, ACDF, and 3+ level PCF procedures. ACCFs were significantly more likely than ACDFs to require reoperation. Patients treated with PCF were consistently more likely to have nondysphagia-related complications than those treated with ACDF. Rates of transfusion, dysphagia, and hematoma/seroma formation were significantly increased with ACCF compared with ACDF within the elderly population. Conclusion. The elderly are significantly less likely to have a revision surgery after surgical treatment for CSM. Patients treated with ACCF are more likely to need a revision than those treated with ACDF. Level of Evidence: 3