Faculty Bibliography

BACKGROUND:Novel methods in predicting survival in patients with spinal metastases may help guide clinical decision-making and stratify treatments regarding surgery vs palliative care. OBJECTIVE:To evaluate whether the frailty/sarcopenia paradigm is predictive of survival and morbidity in patients undergoing surgery for spinal metastasis. METHODS:A total of 271 patients from 4 tertiary care centers who had undergone surgery for spinal metastasis were identified. Frailty/sarcopenia was defined by psoas muscle size. Survival hazard ratios were calculated using multivariate analysis, with variables from demographic, functional, oncological, and surgical factors. Secondary outcomes included improvement of neurological function and postoperative morbidity. RESULTS:Patients in the smallest psoas tertile had shorter overall survival compared to the middle and largest tertile. Psoas size (PS) predicted overall mortality more strongly than Tokuhashi score, Tomita score, and Karnofsky Performance Status (KPS). PS predicted 90-d mortality more strongly than Tokuhashi score, Tomita score, and KPS. Patients with a larger PS were more likely to have an improvement in deficit compared to the middle tertile. PS was not predictive of 30-d morbidity. CONCLUSION/CONCLUSIONS:In patients undergoing surgery for spine metastases, PS as a surrogate for frailty/sarcopenia predicts 90-d and overall mortality, independent of demographic, functional, oncological, and surgical characteristics. The frailty/sarcopenia paradigm is a stronger predictor of survival at these time points than other standards. PS can be used in clinical decision-making to select which patients with metastatic spine tumors are appropriate surgical candidates.

OBJECTIVE:Rigid multiplanar thoracolumbar adult spinal deformity (ASD) cases are challenging and many require a 3-column osteotomy (3CO), specifically asymmetrical pedicle subtraction osteotomy (APSO). The outcomes and additional risks of performing APSO for the correction of concurrent sagittal-coronal deformity have yet to be adequately studied. METHODS:The authors performed a retrospective review of all ASD patients who underwent 3CO during the period from 2006 to 2019. All cases involved either isolated sagittal deformity (patients underwent standard PSO) or concurrent sagittal-coronal deformity (coronal vertical axis [CVA] ≥ 4.0 cm; patients underwent APSO). Perioperative and 2-year follow-up outcomes were compared between patients with isolated sagittal imbalance who underwent PSO and those with concurrent sagittal-coronal imbalance who underwent APSO. RESULTS:A total of 390 patients were included: 338 who underwent PSO and 52 who underwent APSO. The mean patient age was 64.6 years, and 65.1% of patients were female. APSO patients required significantly more fusions with upper instrumented vertebrae (UIV) in the upper thoracic spine (63.5% vs 43.3%, p = 0.007). Radiographically, APSO patients had greater deformity with more severe preoperative sagittal and coronal imbalance: sagittal vertical axis (SVA) 13.0 versus 10.7 cm (p = 0.042) and CVA 6.1 versus 1.2 cm (p < 0.001). In APSO cases, significant correction and normalization were achieved (SVA 13.0-3.1 cm, CVA 6.1-2.0 cm, lumbar lordosis [LL] 26.3°-49.4°, pelvic tilt [PT] 38.0°-20.4°, and scoliosis 25.0°-10.4°, p < 0.001). The overall perioperative complication rate was 34.9%. There were no significant differences between PSO and APSO patients in rates of complications (overall 33.7% vs 42.3%, p = 0.227; neurological 5.9% vs 3.9%, p = 0.547; medical 20.7% vs 25.0%, p = 0.482; and surgical 6.5% vs 11.5%, p = 0.191, respectively). However, the APSO group required significantly longer stays in the ICU (3.1 vs 2.3 days, p = 0.047) and hospital (10.8 vs 8.3 days, p = 0.002). At the 2-year follow-up, there were no significant differences in mechanical complications, including proximal junctional kyphosis (p = 0.352), pseudarthrosis (p = 0.980), rod fracture (p = 0.852), and reoperation (p = 0.600). CONCLUSIONS:ASD patients with significant coronal imbalance often have severe concurrent sagittal deformity. APSO is a powerful and effective technique to achieve multiplanar correction without higher risk of morbidity and complications compared with PSO for sagittal imbalance. However, APSO is associated with slightly longer ICU and hospital stays.

STUDY DESIGN/UNASSIGNED:Retrospective cohort study. OBJECTIVE/UNASSIGNED:Thoracolumbar 3-column osteotomy (3CO) is a powerful technique for correction of rigid adult spinal deformity (ASD). However, it can be associated with high-volume blood loss. This study seeks to investigate the efficacy and safety of tranexamic acid (TXA) in 3CO ASD patients. METHODS/UNASSIGNED:ASD patients who underwent 3CO from 2006 to 2019 were retrospectively reviewed. Outcomes were compared between TXA and non-TXA patients, and TXA doses. RESULTS/UNASSIGNED:= .190) stays. There were no differences in outcomes between TXA dosing subgroups. CONCLUSIONS/UNASSIGNED:Systemic TXA use during 3CO for ASD surgery was not associated with decreased blood loss. TXA patients had shorter operative times, but this was driven mainly by surgeon experience on multivariate analysis. Routine use of TXA is safe and does not increase the incidence of hypercoagulable complications even at high doses.

BACKGROUND:Asymmetric pedicle subtraction osteotomy (APSO) can be utilized for adult spinal deformity (ASD) with fixed coronal plane imbalance. There are few reports investigating outcomes following APSO and no series that include multiple revision cases. OBJECTIVE:To detail our surgical technique and experience with APSO. METHODS:All thoracolumbar ASD cases with a component of fixed, coronal plane deformity who underwent APSO from 2004 to 2016 at one institution were retrospectively reviewed. Preoperative and latest follow-up radiographic parameters and data on surgical outcomes and complications were obtained. RESULTS:Fourteen patients underwent APSO with mean follow-up of 37-mo. Ten (71.4%) were revision cases. APSO involved a mean 12-levels (range 7-25) and were associated with 3.0 L blood loss (range 1.2-4.5) and 457-min of operative time (range 283-540). Surgical complications were observed in 64.3%, including durotomy (35.7%), pleural injury (14.3%), persistent neurologic deficit (14.3%), rod fracture (7.1%), and painful iliac bolt requiring removal (7.1%). Medical complications were observed in 14.3%, comprising urosepsis and 2 cases of pneumonia. Two 90-d readmissions (14.3%) and 5 reoperations (4 patients, 28.6%) occurred. Mean thoracolumbar curve and coronal vertical axis improved from 31.5 to 16.4 degrees and 7.8 to 2.9 cm, respectively. PI-LL mismatch, mean sagittal vertical axis, and pelvic tilt improved from 40.0 to 27.9-degrees, 10.7 to 3.5-cm, and 34.4 to 28.3-degrees, respectively. CONCLUSION:The APSO, in both a revision and non-revision ASD population, provides excellent restoration of coronal balance-in addition to sagittal and pelvic parameters. Employment of APSO must be balanced with the associated surgical complication rate (64.3%).

OBJECTIVE:It is being increasingly recognized that adult cervical deformity (ACD) is correlated with significant pain, myelopathy, and disability, and that patients who undergo deformity correction gain significant benefit. However, there are no defined thresholds of minimum clinically important difference (MCID) in Neck Disability Index (NDI) and modified Japanese Orthopaedic Association (mJOA) scores. METHODS:Patients of interest were consecutive patients with ACD who underwent cervical deformity correction. ACD was defined as C2-7 sagittal Cobb angle ≥ 10° (kyphosis), C2-7 coronal Cobb angle ≥ 10° (cervical scoliosis), C2-7 sagittal vertical axis ≥ 4 cm, and/or chin-brow vertical angle ≥ 25°. Data were obtained from a consecutive cohort of patients from a multiinstitutional prospective database maintained across 13 sites. Distribution-based MCID, anchor-based MCID, and minimally detectable measurement difference (MDMD) were calculated. RESULTS:A total of 73 patients met inclusion criteria and had sufficient 1-year follow-up. In the cohort, 42 patients (57.5%) were female. The mean age at the time of surgery was 62.23 years, and average body mass index was 29.28. The mean preoperative NDI was 46.49 and mJOA was 13.17. There was significant improvement in NDI at 1 year (46.49 vs 37.04; p = 0.0001). There was no significant difference in preoperative and 1-year mJOA (13.17 vs 13.7; p = 0.12). Using multiple techniques to yield MCID thresholds specific to the ACD population, the authors obtained values of 5.42 to 7.48 for the NDI, and 1.00 to 1.39 for the mJOA. The MDMD was 6.4 for the NDI, and 1.8 for the mJOA. Therefore, based on their results, the authors recommend using an MCID threshold of 1.8 for the mJOA, and 7.0 for the NDI in patients with ACD. CONCLUSIONS:The ACD-specific MCID thresholds for NDI and mJOA are similar to the reported MCID following surgery for degenerative cervical disease. Additional studies are needed to verify these findings. Nonetheless, the findings here will be useful for future studies evaluating the success of surgery for patients with ACD undergoing deformity correction.

BACKGROUND:Resection may be appropriate for select patients with recurrent glioblastoma. The incidence of histopathological findings related to prior treatment and their prognostic implications are incompletely characterized. OBJECTIVE:To quantify the incidence and survival outcomes associated with treatment effect at resection of recurrent glioblastoma (GBM). METHODS:Patients who underwent resection for recurrent GBM were retrospectively reviewed, and pathology, treatment history, and survival data were collected. Treatment effect was defined as any component of treatment-related changes on pathology. RESULTS:In total, 110 patients underwent 146 reoperations. Median age at first reoperation was 57.2 yr and overall survival from reoperation was 10.8 mo. Treatment effect of any kind was noted in 81 of 146 reoperations (55%). Increased treatment effect was observed closer to radiotherapy; by quartile of time from radiotherapy, the rates of treatment effect were 77.8%, 55.6%, 40.7%, and 44.4% (P = .028). Treatment effect was associated with earlier reoperation (8.9 vs 13.8 mo after radiotherapy, P = .003), and the presence of treatment effect did not impact survival from primary surgery (25.4 vs 24.3 mo, P = .084). Patients treated with bevacizumab prior to reoperation were less likely to have treatment effect (20% vs 65%, P < .001). CONCLUSION:Histopathological treatment-related changes are evident in a majority of patients undergoing resection for recurrent glioblastoma. There was no association of treatment effect with overall survival from primary surgery.

Adult spinal deformity (ASD) is a complex disease that significantly affects the lives of many patients. Surgical correction has proven to be effective in achieving improvement of spinopelvic parameters as well as improving quality of life (QoL) for these patients. However, given the relatively high complication risk associated with ASD correction, it is of paramount importance to develop robust prognostic tools for predicting risk profile and outcomes. Historically, statistical models such as linear and logistic regression models were used to identify preoperative factors associated with postoperative outcomes. While these tools were useful for looking at simple associations, they represent generalizations across large populations, with little applicability to individual patients. More recently, predictive analytics utilizing artificial intelligence (AI) through machine learning for comprehensive processing of large amounts of data have become available for surgeons to implement. The use of these computational techniques has given surgeons the ability to leverage far more accurate and individualized predictive tools to better inform individual patients regarding predicted outcomes after ASD correction surgery. Applications range from predicting QoL measures to predicting the risk of major complications, hospital readmission, and reoperation rates. In addition, AI has been used to create a novel classification system for ASD patients, which will help surgeons identify distinct patient subpopulations with unique risk-benefit profiles. Overall, these tools will help surgeons tailor their clinical practice to address patients' individual needs and create an opportunity for personalized medicine within spine surgery.

OBJECTIVE:Posterior-based thoracolumbar 3-column osteotomy (3CO) is a formidable surgical procedure. Surgeon experience and case volume are known factors that influence surgical complication rates, but these factors have not been studied well in cases of adult spinal deformity (ASD). This study examines how surgeon experience affects perioperative complications and operative measures following thoracolumbar 3CO in ASD. METHODS:A retrospective study was performed of a consecutive cohort of thoracolumbar ASD patients who underwent 3CO performed by the senior authors from 2006 to 2018. Multivariate analysis was used to assess whether experience (years of experience and/or number of procedures) is associated with perioperative complications, operative duration, and blood loss. RESULTS:A total of 362 patients underwent 66 vertebral column resections (VCRs) and 296 pedicle subtraction osteotomies (PSOs). The overall complication rate was 29.4%, and the surgical complication rate was 8.0%. The rate of postoperative neurological deficits was 6.2%. There was a trend toward lower overall complication rates with greater operative years of experience (from 44.4% to 28.0%) (p = 0.115). Years of operative experience was associated with a significantly lower rate of neurological deficits (p = 0.027); the incidence dropped from 22.2% to 4.0%. The mean operative time was 310.7 minutes overall. Both increased years of experience and higher case numbers were significantly associated with shorter operative times (p < 0.001 and p = 0.001, respectively). Only operative years of experience was independently associated with operative times (p < 0.001): 358.3 minutes from 2006 to 2008 to 275.5 minutes in 2018 (82.8 minutes shorter). Over time, there was less deviation and more consistency in operative times, despite the implementation of various interventions to promote fusion and prevent construct failure: utilization of multiple-rod constructs (standard, satellite, and nested rods), bone morphogenetic protein, vertebroplasty, and ligament augmentation. Of note, the use of tranexamic acid did not significantly lower blood loss. CONCLUSIONS:Surgeon years of experience, rather than number of 3COs performed, was a significant factor in mitigating neurological complications and improving quality measures following thoracolumbar 3CO for ASD. The 3- to 5-year experience mark was when the senior surgeon overcame a learning curve and was able to minimize neurological complication rates. There was a continuous decrease in operative time as the surgeon's experience increased; this was in concurrence with the implementation of additional preventative surgical interventions. Ongoing practice changes should be implemented and can be done safely, but it is imperative to self-assess the risks and benefits of those practice changes.

OBJECTIVEThe elderly are a growing subpopulation within traumatic spinal cord injury (SCI) patients. Studies have reported high morbidity and mortality rates in elderly patients who undergo surgery for SCI. In this study, the authors compare the perioperative outcomes of surgically managed elderly SCI patients with those of a younger cohort and those reported in the literature.METHODSData on a consecutive series of adult traumatic SCI patients surgically managed at a single institution in the period from 2007 to 2017 were retrospectively reviewed. The cohort was divided into two groups based on age: younger than 70 years and 70 years or older. Assessed outcomes included complications, in-hospital mortality, intensive care unit (ICU) stay, hospital length of stay (LOS), disposition, and neurological status.RESULTSA total of 106 patients were included in the study: 83 young and 23 elderly. The two groups were similar in terms of imaging features (cord hemorrhage and fracture), operative technique, and American Spinal Injury Association Impairment Scale (AIS) grade. The elderly had a significantly higher proportion of cervical SCIs (95.7% vs 71.1%, p = 0.047). There were no significant differences between the young and the elderly in terms of the ICU stay (13.1 vs 13.3 days, respectively, p = 0.948) and hospital LOS (23.3 vs 21.7 days, p = 0.793). Elderly patients experienced significantly higher complication (73.9% vs 43.4%, p = 0.010) and mortality (13.0% vs 1.2%, p = 0.008) rates; in other words, the elderly patients had 1.7 times and 10.8 times the rate of complications and mortality, respectively, than the younger patients. No elderly patients were discharged home (0.0% vs 18.1%, p = 0.029). Discharge AIS grade and AIS grade change were similar between the groups.CONCLUSIONSElderly patients had higher complication and mortality rates than those in younger patients and were less likely to be discharged home. However, it does seem that mortality rates have improved compared to those in prior historical reports.