Joseph Cheng

In Reply: Incidence and Predictive Factors of Sepsis Following Adult Spinal Deformity Surgery

To the Editor: We appreciate the thought-provoking letter1 in response to our original article, Incidence and Predictive Factors of Sepsis Following Adult Spinal Deformity Surgery.2 Themention of “sparse data bias” is important, especially when aiming to predict rare complications using large databases. In our statistical analysis, preoperative factors demonstrating univariate associations of P< .10 were incorporated into the multivariable model, a statistical method used in many clinical studies of adult spinal deformity (ASD) and large databases.3-9 We certainly agree that the confidence interval for the preoperative risk factor “ascites” was wide, and significance should be interpreted with caution. This was likely due to the low number of patients with ascites, which was 4 out of 6158. An alternative option would have been to remove this variable altogether given the low number of patients. We wholeheartedly agree with the author’s concluding statement that “sparse data bias” should be more widely addressed in the literature to avoid spurious statistical associations. While the request for reanalysis of the data through penalization mentioned is worthy, we will instead look forward and use this constructive suggestion for future studies. Perhaps more important is to qualify the a priori objective of the present study, which is similar to other NSQIP analyses.3-5,10-14 Our a priori objective was to better understand risk factors for the rare and devastating complication of sepsis and draw conclusions that are difficult to ascertain from single institution studies. These data were not intended to provide definitive or finite risk factors for sepsis. The concluding point is for surgeons and anesthesiologists to understand the possible—not absolute—risk for patients with ascites, decompensated cirrhosis, or end stage liver disease, in potentially developing sepsis after a large ASD surgery. Preoperative liver function has not typically been studied in predictive studies examining morbidity and mortality following ASD surgery,3,8,9,15 and despite the wide confidence interval, we felt it most beneficial to the spine surgery community to report this information. It is our hope these data can be used to improve clinical care and inform future research. We thank the authors for their interest in our article and constructive commentary.

The Impact of Chronic Kidney Disease on Postoperative Outcomes in Patients Undergoing Lumbar Decompression and Fusion

OBJECTIVEnTo determine whether preoperative chronic kidney disease (CKD) is associated with inferior perioperative outcomes in patients undergoing lumbar arthrodesis.nnnMETHODSnMedical records of 293 adult (≥18 years old) patients with spine deformity undergoing elective lumbar spine decompression and fusion at a major academic institution from 2006 to 2015 were reviewed. We identified 18 (6.1%) patients with a clinical diagnosis of CKD (CKDxa0group, nxa0= 18; no-CKD group, nxa0= 275). Patient demographics, comorbidities, and intraoperative and postoperative complication rates were collected for each patient. The primary endpoint was incidence of postoperative complications.nnnRESULTSnPatient demographics, including age, sex, and body mass index, and comorbidities were similar between cohorts. The CKD group had a significantly higher prevalence of hypertension, hyperlipidemia, and anemia compared with the no-CKD group. Median number of fusion levels, length of surgery, and estimated blood loss were similar between both cohorts. Postoperative complication profile was significantly different between the cohorts, with the CKD group having a significantly higher proportion of patients transferred to the intensive care unit (52.9% vs. 29.3%, Pxa0= 0.04) with episodes of delirium (27.8% vs. 8.4%, Pxa0= 0.007), urinary tract infection (27.8% vs. 6.9%, Pxa0=xa00.0002), and deep vein thrombosis (5.6% vs. 0.4%, Pxa0= 0.01). Although not significant, the CKD group had a 2-fold higher rate of 30-day readmissions compared with the no-CKD group (CKD group: 27.8% vs. no-CKD group: 12.7%, Pxa0= 0.07).nnnCONCLUSIONSnOur study suggests that patients with CKD may be more likely to develop perioperative complications after lumbar arthrodesis. Future studies are necessary to corroborate our findings.

Registries in Spine Care in the United States

Spinal disorders are extremely common, debilitating, and costly to patients, payers, and society as a whole (Skovrlj B, Gologorsky Y, Haque R, Fessler RG, Qureshi SA. Complications, outcomes, and need for fusion after minimally invasive posterior cervical foraminotomy and microdiscectomy. Spine J 14:2405–2411, 2014). The increasing frequency of spinal related interventions along with increasing cost has triggered a paradigm shift to the delivery of value-based spine care (Roder C, Muller U, Aebi M. The rationale for a spine registry. Eur Spine J 15:S52–S56, 2006). The goal of this shift is the expected convergence of the interests of patients, payers, politicians, and clinicians. Value in healthcare is expressed as patient-centered outcomes (effectiveness of care) divided by related cost of care. Integral to the value equation is the ability to track patient outcomes longitudinally over time. Health registries, when designed properly, have the potential to provide the necessary statistical power and real-world setting required for true value measurement in both individuals and populations. In this chapter, we provide a summary of spinal registries in the United States.

Impact of Chronic Obstructive Pulmonary Disease on Postoperative Complication Rates, Ambulation, and Length of Hospital Stay After Elective Spinal Fusion (≥3 Levels) in Elderly Spine Deformity Patients

OBJECTIVEnTo investigate the impact that chronic obstructive pulmonary disease (COPD) has on postoperative complication rates, ambulation, and hospital length of stay for elderly spinal deformity patients after elective spinal fusion (≥3 levels).nnnMETHODSnThe medical records of 559 elderly (≥60 years old) spine deformity patients undergoing elective spinal fusion (≥3 levels) at a major academic institution from 2005 to 2015 were reviewed. We identified 60 patients with COPD (10.7%) and 499 patients without COPD (89.3%). Patient demographics, comorbidities, postoperative complications, ambulatory status, and readmission rates were collected. The primary outcomes investigated in this study were complication rates and length of hospital stay.nnnRESULTSnDemographics and comorbidities were similar between groups, with a difference in proportion of smokers (COPD group: 25.0% vs. no COPD group: 9.6%, Pxa0= 0.0004). The median number of fusion levels (Pxa0=xa00.840), operative time (Pxa0= 0.842), estimated blood loss (Pxa0= 0.336), and incidences of durotomy (Pxa0= 0.258) was similar between both cohorts. The COPD cohort experienced a higher rate of postoperative fever (10.0% vs. 3.0%, Pxa0= 0.007) and pneumonia (5.0% vs. 0.4%, Pxa0= 0.0004), respectively. There was a significant difference in the number of feet walked on the first day of ambulation after surgery (COPD group: 58.6 ± 78.4 vs. no COPD group: 84.0 ± 102.8, Pxa0= 0.040). Length of hospital stay was significantly longer in the COPD cohort than the no COPD cohort (7.7 ± 6.4 vs. 6.0 ± 4.0 days, respectively; Pxa0= 0.0498).nnnCONCLUSIONSnOur study demonstrates that elderly patients with COPD have increased lengths of stay and higher rates of postoperative pneumonia after spinal fusion. This determination identifies a potentially modifiable risk factor for increased utilization of health care resources.

Gender Differences in Use of Prolonged Non-Operative Therapies Prior to Index Lumbar Surgery

OBJECTIVEnThe purpose of the present study was to assess for gender-based differences in the usage and cost of maximal nonoperative therapy before spinal fusion surgery in patients with symptomatic lumbar stenosis or spondylolisthesis.nnnMETHODSnA large insurance database was queried for patients with symptomatic lumbar stenosis or spondylolisthesis undergoing index lumbar decompression and fusion procedures from 2007 to 2016. This database consists of 20.9 million covered lives and includes private or commercially insured and Medicare Advantage beneficiaries. Only patients continuously active within the Humana insurance system for ≥5 years before the index operation were eligible. Usage was characterized by the cost billed to the patient, prescriptions written, and number of units billed.nnnRESULTSnA total of 4133 patients (58.5% women) underwent 1-, 2-, or 3-level posterior lumbar instrumented fusion. A significantly greater percentage of female patients used nonsteroidal anti-inflammatory drugs (Pxa0<xa00.0001), lumbar epidural steroid injections (Pxa0=xa00.0044), physical and/or occupational therapy (Pxa0<xa00.0001), and muscle relaxants (P < 0.0001). The total direct cost associated with all maximal nonoperative therapy before index spinal fusion was

Interdisciplinary Care Model Independently Decreases Use of Critical Care Services After Corrective Surgery for Adult Degenerative Scoliosis

9,000,968, with men spending

Does Nasal Carriage of Staphylococcus aureus Increase the Risk of Postoperative Infections After Elective Spine Surgery: Do Most Infections Occur in Carriers?

3,451,479 (

Preoperative Hemoglobin Level is Associated with Increased Health Care Use After Elective Spinal Fusion (≥3 Levels) in Elderly Male Patients with Spine Deformity

2011.35 per patient) and women spending

Extended Length of Stay in Elderly Patients After Lumbar Decompression and Fusion Surgery May Not Be Attributable to Baseline Illness Severity or Postoperative Complications

5,549,489 (

Extended Length of Stay in Elderly Patients after Anterior Cervical Discectomy and Fusion Is Not Attributable to Baseline Illness Severity or Postoperative Complications

2296.02 per patient). When considering the quantity of units billed, women used 61.5% of the medical therapy units disbursed despite constituting 58.5% of the cohort. When normalized by the number of pills billed per patient using therapy, female patients used more nonsteroidal anti-inflammatory drugs, opioids, and muscle relaxants.nnnCONCLUSIONSnThese results suggest that gender differences exist in the use of nonoperative therapies for symptomatic lumbar stenosis or spondylolisthesis before fusion surgery.