Determinants of Postoperative Spinal Height Change among Adult Spinal Deformity Patients with Long Construct Circumferential Fusion

Methods@#We retrospectively reviewed the clinical and imaging data of ASD patients who underwent lumbar corrective circumferential fusion of ≥3 levels (n=106). SH was defined as the vertical distance between C2 and S1 on a standing lateral image. As potential predictors of postoperative height change, the number of lateral lumbar interbody fusion (LLIF) levels, change in spino-pelvic parameters, total number of levels fused, and pedicle subtraction osteotomies (PSO) were documented. Univariate and multivariate linear regression analyses were performed to identify the predictors of postoperative height change. @*Results@#The mean SH change was −2.39±50.8 mm (range, −160 to 172 mm). The univariate analyses showed that the number of LLIF levels (coefficient=10.9, p=0.03), the absolute coronal vertical axis change (coefficient=0.6, p=0.01), and the absolute Cobb angle change (coefficient=−0.9, p=0.03) were significant predictors for height change. Patients with PSOs (n=14) tended to have a shorter height postoperatively (coefficient=−26.1); however, this difference was not significant (p=0.07). Multivariate analyses conducted with variables of pp=0.04, R2=0.11). @*Conclusions@#Utilizing a modified definition of SH used in previous AIS studies, we demonstrated that patients with ASD lose SH postoperatively and that PT change was an independent contributor of SH change.

Determinants of Postoperative Spinal Height Change among Adult Spinal Deformity Patients with Long Construct Circumferential Fusion

Methods@#We retrospectively reviewed the clinical and imaging data of ASD patients who underwent lumbar corrective circumferential fusion of ≥3 levels (n=106). SH was defined as the vertical distance between C2 and S1 on a standing lateral image. As potential predictors of postoperative height change, the number of lateral lumbar interbody fusion (LLIF) levels, change in spino-pelvic parameters, total number of levels fused, and pedicle subtraction osteotomies (PSO) were documented. Univariate and multivariate linear regression analyses were performed to identify the predictors of postoperative height change. @*Results@#The mean SH change was −2.39±50.8 mm (range, −160 to 172 mm). The univariate analyses showed that the number of LLIF levels (coefficient=10.9, p=0.03), the absolute coronal vertical axis change (coefficient=0.6, p=0.01), and the absolute Cobb angle change (coefficient=−0.9, p=0.03) were significant predictors for height change. Patients with PSOs (n=14) tended to have a shorter height postoperatively (coefficient=−26.1); however, this difference was not significant (p=0.07). Multivariate analyses conducted with variables of pp=0.04, R2=0.11). @*Conclusions@#Utilizing a modified definition of SH used in previous AIS studies, we demonstrated that patients with ASD lose SH postoperatively and that PT change was an independent contributor of SH change.

Serotonergic Antidepressants Are Associated with Increased Blood Loss and Risk for Transfusion in Single-Level Lumbar Fusion Surgery

STUDY DESIGN: Retrospective case-control study. PURPOSE: The purpose of this study was to examine the effect of antidepressants on blood loss and transfusion requirements in spinal surgery patients. OVERVIEW OF LITERATURE: Several studies have shown an increase in perioperative bleeding in orthopedic surgery patients on antidepressant drug therapy, yet no study has examined the impact of these agents on spinal surgery patients. METHODS: Charts of patients who underwent single-level spinal fusion (posterior lumbar interbody fusion with posterior instrumentation) performed by five fellowship-trained surgeons at a tertiary spine center between 2008 and 2013, were retrospectively reviewed. Exclusion criteria included select medical comorbidities, select drug therapy, and Amercian Society of Anesthesiologists Physical Status Classification score of greater than 2. Serotonergic antidepressants were examined in multivariate analysis to assess their predictive value on estimated blood loss and risk of transfusion. RESULTS: A total of 235 patients, of which 52% were female, were included. Allogeneic blood was transfused in 7% of patients. The average estimated blood loss was 682±463 mL. Selective serotonin reuptake inhibitors were taken by 10% of all patients. Multivariable regression analysis showed that intake of selective serotonin reuptake inhibitors was a significant predictor for blood loss (average increase of 34%, p=0.015) and for the need of allogeneic blood transfusion (odds ratio, 4.550; p=0.029). CONCLUSIONS: There was a statistically significant association between selective serotonin reuptake inhibitors and both increased blood loss and risk of allogeneic red blood cell transfusion. Surgeons and perioperative providers should take these findings into account when assessing patients' preoperative risk for blood loss and transfusion.

A Comparative Study of Lateral Lumbar Interbody Fusion and Posterior Lumbar Interbody Fusion in Degenerative Lumbar Spondylolisthesis

STUDY DESIGN: Level 4 retrospective review. PURPOSE: To compare the radiographic and clinical outcomes between posterior lumbar interbody fusion (PLIF) and lateral lumbar interbody fusion (LLIF) with posterior segmental spinal instrumentation (SSI) for degenerative lumbar spondylolisthesis. OVERVIEW OF LITERATURE: Both PLIF and LLIF have been performed for degenerative spondylolisthesis with good results, but no study has directly compared these two techniques so far. METHODS: The electronic medical and radiographic records of 78 matched patients were analyzed. In one group, 39 patients underwent PLIF with SSI at 41 levels (L3-4/L4-5), while in the other group, 39 patients underwent the LLIF procedure at 48 levels (L3-4/L4-5). Radiological outcomes such as restoration of disc height and neuroforaminal height, segmental lumbar lordosis, total lumbar lordosis, incidence of endplate fracture, and subsidence were measured. Perioperative parameters were also recorded in each group. Clinical outcome in both groups was assessed by the short form-12, Oswestry disability index and visual analogue scale scores. The average follow-up period was 16.1 months in the LLIF group and 21 months in the PLIF group. RESULTS: The restoration of disc height, foraminal height, and segmental lumbar lordosis was significantly better in the LLIF group (p<0.001). The duration of the operation was similar in both groups, but the average blood loss was significantly lower in the LLIF group (p<0.001). However, clinical outcome scores were similar in both groups. CONCLUSIONS: Safe, effective interbody fusion can be achieved at multiple levels with neuromonitoring by the lateral approach. LLIF is a viable treatment option in patients with new onset symptoms due to degenerative spondylolisthesis who have had previous lumbar spine surgery, and it results in improved sagittal alignment and indirect foraminal decompression.