Crandall, Dennis G.

Background: To analyze gender differences regarding the recovery experience (pain, function, complications) after spinal arthrodesis surgery. Methods: Pre-operative and post-operative gender-based differences in patient-reported outcomes for open posterior spinal arthrodesis at 6 weeks, 3 months, 6 months, and 1 year were studied, including age, comorbidities, body mass index (BMI), diagnosis, number of vertebrae fused, type of surgery, primary vs. revision surgery, and complications. Statistical analysis included the use of Student’s t-test, Chi square, linear regression, Mann–Whitney U test, and Spearman’s rho. Results: Primary or revision posterior arthrodesis was performed on 1931 consecutive adults (1219 females, 712 males) for deformity and degenerative pathologies. At surgery, females were older than males (61.7 years vs. 59.7 years, p < 0.01), had slightly more comorbidities (1.75 vs. 1.5, p < 0.01), and were more likely to undergo deformity correction (38% vs. 22%, p < 0.01). Females described more pre-op pain (female VAS = 6.54 vs. male VAS = 6.41, p < 0.01) and lower pre-op function (female ODI = 49.73 vs. male ODI = 46.52, p < 0.01). By 3 months post-op, there was no significant gender difference in VAS or ODI scores. Similar pain and function scores between males and females continued through 6 months and 12 months. Conclusion: Although females have more pain and dysfunction before undergoing spinal surgery, the differences in these values do not reach the Minimum Clinically Important Difference (MCID). Post-operatively, there is no difference in pain and function scores among males and females at 3, 6, and 12 months.

Study Design. Retrospective review of prospectively collected data. Objective. To determine if the addition of L5-S1 interbody support in long fusion deformity constructs is associated with superior long-term clinical and radiographic outcomes. To compare the 5-year clinical and radiographic outcomes and complications between long fusion constructs with L5-S1 interbody support versus posterolateral fusion (PLF) alone. Summary of Background Data. Cadaveric biomechanical studies have suggested that an interbody fusion at L5-S1 is beneficial in long fusion constructs with sacropelvic fixation. However, there is limited data reflecting the superiority of interbody support augmentation in optimizing arthrodesis and deformity correction relative to PLF alone. Methods. Eighty-eight consecutive adults with spinal deformity who underwent at minimum T11-pelvis posterior pedicle screw instrumentation with 5-year follow-up were included. Two cohorts were compared based on technique used at the lumbosacral junction (L5-S1): (A) no interbody (PLF; n = 23), or (B) interbody support at L5-S1 (IB; n = 65). Radiographic measurements and clinical outcome measures were compared at multiple time points. Complications were recorded and compared. Results. No differences in baseline patient characteristics between cohorts. One nonunion occurred at L5-S1 in the PLF group (P = 0.091). Initial postop sagittal alignment was better in the IB group (PLF: 6.46 cm, IB: 2.48 cm, P = 0.007); however, this was not maintained over long-term follow-up. No significant differences in proximal junctional kyphosis (PLF: 7/23, IB: 9/65, P = 0.076). Proximal junctional failure was more frequent in the PLF group (PLF: 6/23, IB: 6/65, P = 0.043). No significant differences in complications were found. Both cohorts had improvement from baseline pain and functional scores. Conclusion. There is no absolute long-term advantage for lumbar interbody support in adult spinal deformity patients undergoing spinal arthrodesis to the pelvis. Level of Evidence: 3

Study Design: Retrospective cohort study. Objective: To determine if local administration of liposomal bupivacaine (LB) reduces postoperative pain scores and narcotic use in spinal deformity patients. Methods: Adult patients undergoing elective spinal fusion (7 or more levels) for scoliosis or kyphosis were selected for inclusion. Patients received either periincisional injections of combined liposomal and standard bupivacaine (n = 90, group L) or standard bupivacaine only (n = 69, group C). Perioperative pain scores (VAS [visual analogue scale]), opioid use, length of stay, functional outcome (ODI [Oswestry Disability Index]), and perioperative complications were recorded. No external funding was received for this study. Results: A total of 159 patients met inclusion criteria (mean age was 54.2 years of age). No significant baseline demographic differences were noted between the 2 groups. Group L experienced slight improvements in pain control on postoperative day (POD) 1 ( P = .02). No difference in pain scores were otherwise noted. Group L transitioned off of intravenous (IV) narcotics faster with 52.6% less IV use by POD3 ( P = .03). No differences in total narcotic consumption, perioperative complications, lengths of stay, and functional outcome scores were otherwise noted between the 2 cohorts. Conclusions: The use of LB in adult spinal deformity surgery does not appear to provide clinically important improvements in postoperative pain at the manufacturer’s recommended dosage. Furthermore, while patients receiving LB may transition more quickly off of IV narcotics, this does not appear to translate into an overall decrease in narcotic consumption, hasten return of bowel function, or decrease hospital lengths of stay. Future prospective randomized control trials are warranted. The use of varying dosages of LB may also help further clarify the true efficacy of LB in the setting of spinal deformity surgery.

Study Design. A retrospective cohort study. Objective. The aim of this study was to evaluate the effect of preoperative dehydration on hospital length of stay (LOS), rates of 30-day postoperative complications, related reoperations, and readmissions. Summary of Background Data. Preoperative dehydration has long been associated with postoperative infection, deep vein thrombosis (DVT), acute renal failure, and an increased hospital LOS. To our knowledge, the effect of preoperative dehydration on complication rates for patients undergoing elective lumbar spine surgery has not been well described. Methods. An analysis of American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) data from 2006 to 2013 was performed. Patients undergoing elective lumbar procedures were identified and exclusion criteria eliminated patients who underwent any emergency procedures, infections, tumor cases, or revision surgeries. Patient dehydration was defined as preoperative blood urea nitrogen/creatinine (BUN/Cr) ratio greater than 20. Results. Patients (4698; 34.5%) with preoperative dehydration based on BUN/Cr ratio were identified. Univariate analysis was suggestive of an association between preoperative dehydration and an increased risk of DVT (1.1% compared with 0.6%; P = 0.002), urinary tract infection (2.5% compared with 1.6%; P < 0.001), and need for transfusion postoperatively (17.6% compared with 14.4%; P < 0.001). However, on the basis of multivariate regression, no significant association between dehydration and increased odds of aforementioned outcomes was identified. Conclusion. Preoperative dehydration does not appear to negatively affect perioperative outcomes or readmission in patients undergoing elective lumbar spine surgery. Level of Evidence: 3

Study Design. A retrospective cohort study. Objective. The aim of this study was to evaluate the effect of metabolic syndrome (MetS) on 30-day morbidity and mortality following elective lumbar spinal fusion. Summary of Background Data. MetS is a variable combination of hypertension, obesity, elevated fasting plasma glucose, and dyslipidemia. MetS has been associated with an increased risk of postoperative morbidity and mortality in multiple surgical settings. To our knowledge, the effect of MetS on 30-day outcomes following elective lumbar spinal fusion has not been well studied. Methods. An analysis of ACS-NSQIP data was performed between 2006 and 2013. Patients undergoing elective posterior lumbar fusion were identified. Emergency procedures, infections, tumor cases, and revision surgeries were excluded. Patients were defined as having MetS if they had a history of hypertension requiring medication, diabetes, and a body mass index (BMI) ≥30 kg/m2. Results. One thousand five hundred ninety (10.2%) patients with MetS were identified. A mild increase in major (P = 0.040) and minor complications (P = 0.003) in patients with MetS was noted. MetS was associated with increased rates of pulmonary complications (1.9% compared with 1.0%; P = 0.001), sepsis (1.7% compared with 0.9%; P = 0.005), and acute post-op renal failure (0.4% compared with 0%; P < 0.001). Multivariate analysis confirmed MetS to be an independent predictor of pulmonary complications [odds ratio (OR) 1.51; 95% confidence interval (95% CI 1.00–2.27); P = 0.048], sepsis (OR 1.56; 95% CI 1.01–2.42; P = 0.039), and acute postoperative renal failure (OR 6.95; 95% CI 2.23–21.67; P = 0.001). MetS status was associated with a mild increase in total hospital length of stay (4.38 compared with 3.81 days; P < 0.001). Conclusion. While MetS is a predictor of postoperative acute renal failure, it only slightly increases the risk of overall complications and is not associated with increased rates of 30-day reoperations or readmissions following elective lumbar fusion. Level of Evidence: 3