Editorial. Nuances of restoration of lumbar lordosis using an MIS anterior column release versus posterior 3-column osteotomy
Michael S. Virk and Praveen V. Mummaneni
Stereotactic navigation for the prepsoas oblique lateral lumbar interbody fusion: technical note and case series
Anthony M. DiGiorgio, Caleb S. Edwards, Michael S. Virk, Praveen V. Mummaneni, and Dean Chou
The prepsoas retroperitoneal approach is a minimally invasive technique used for anterior lumbar interbody fusion. The approach may have a more favorable risk profile than the transpsoas approach, decreasing the risks that come with dissecting through the psoas muscle. However, the oblique angle of the spine in the prepsoas approach can be disorienting and challenging. This technical report provides an overview of the use of navigation in prepsoas oblique lateral lumbar interbody fusion in a series of 49 patients.
Bone flap explantation, steroid use, and rates of infection in patients with epilepsy undergoing craniotomy for implantation of subdural electrodes
Eliza H. Hersh, Michael S. Virk, Huibo Shao, A. John Tsiouris, Gregory A. Bonci, and Theodore H. Schwartz
Subdural implantation of electrodes is commonly performed to localize an epileptic focus. Whether to temporarily explant the bone plate and whether to treat patients with perioperative steroid agents is unclear. The authors' aim was to evaluate the utility and risk of bone plate explantation and perioperative steroid use.
The authors reviewed the records of all patients who underwent unilateral craniotomy for electrode implantation performed between November 2001 and June 2011 at their institution. Patients were divided into 3 groups: Group 1 (n = 24), bone explanted, no perioperative steroid use; Group 2 (n = 42), bone left in place, no perioperative steroid use; Group 3 (n = 25), bone left in place, steroid agents administered perioperatively. Complications, mass effect, and seizure rates were examined by means of statistical analysis.
Of 324 cranial epilepsy surgeries, 91 were unilateral subdural electrode implants that met our inclusion criteria. A total of 11 infections were reported, and there was a significantly higher rate of infection when the bone was explanted (8 cases [33.3%]) than when the bone was left in place (3 cases [4.5%], p < 0.01). Leaving the bone in place also increased the rate of asymptomatic subdural hematomas and frequency of seizures, although there was no increase in midline shift, severity of headache, or rate of emergency reoperation. The use of steroid agents did not appear to have an effect on any of the outcome measures.
Temporary bone flap explantation during craniotomy for implantation of subdural electrodes can result in high rates of infection, possibly due to the frequent change of hands in transferring the bone to the bone bank. Leaving the bone in place may increase the frequency of seizures and appearance of asymptomatic subdural hematomas but does not increase the rate of complications. These results may be institution dependent.
Editorial. Damage capitation as malpractice reform
Anthony M. DiGiorgio, Michael S. Virk, and Praveen V. Mummaneni
Frequency of symptomatic vertebral body compression fractures requiring intervention following single-fraction stereotactic radiosurgery for spinal metastases
Michael S. Virk, James E. Han, Anne S. Reiner, Lily A. McLaughlin, Daniel M. Sciubba, Eric Lis, Yoshiya Yamada, Mark Bilsky, and Ilya Laufer
The purpose of this study was to determine the rate of symptomatic vertebral body compression fractures (VCFs) requiring kyphoplasty or surgery in patients treated with 24-Gy single-fraction stereotactic radiosurgery (SRS).
This retrospective analysis included all patients who had been treated with 24-Gy, single-fraction, image-guided intensity-modulated radiation therapy for histologically confirmed solid tumor metastases over an 8-year period (2005–2013) at Memorial Sloan Kettering Cancer Center. Charts and imaging studies were reviewed for post-SRS kyphoplasty or surgery for mechanical instability. A Spinal Instability Neoplastic Score (SINS) was calculated for each patient both at the time of SRS and at the time of intervention for VCF.
Three hundred twenty-three patients who had undergone single-fraction SRS between C-1 and L-5 were included in this analysis. The cumulative incidence of VCF 5 years after SRS was 7.2% (95% CI 4.1–10.2), whereas that of death following SRS at the same time point was 82.5% (95% CI 77.5–87.4). Twenty-six patients with 36 SRS-treated levels progressed to symptomatic VCF requiring treatment with kyphoplasty (6 patients), surgery (10 patients), or both (10 patients). The median time to symptomatic VCF was 13 months. Seven patients developed VCF at 11 levels adjacent to the SRS-treated level. Fractured levels had no evidence of tumor progression. The median SINS changed from 6.5 at SRS (interquartile range [IQR] 4.3–8.8) to 11.5 at stabilization (IQR 9–13). In patients without prior stabilization at the level of SRS, there was an association between the SINS and the time to fracture.
Five years after ablative single-fraction SRS to spinal lesions, the cumulative incidence of symptomatic VCF at the treated level without tumor recurrence was 7.2%. Higher SINSs at the time of SRS correlated with earlier fractures.
Applicability of cervical sagittal vertical axis, cervical lordosis, and T1 slope on pain and disability outcomes after anterior cervical discectomy and fusion in patients without deformity
Darryl Lau, Anthony M. DiGiorgio, Andrew K. Chan, Cecilia L. Dalle Ore, Michael S. Virk, Dean Chou, Erica F. Bisson, and Praveen V. Mummaneni
Understanding what influences pain and disability following anterior cervical discectomy and fusion (ACDF) in patients with degenerative cervical spine disease is critical. This study examines the timing of clinical improvement and identifies factors (including spinal alignment) associated with worse outcomes.
Consecutive adult patients were enrolled in a prospective outcomes database from two academic centers participating in the Quality Outcomes Database from 2013 to 2016. Demographics, surgical details, radiographic data, arm and neck pain (visual analog scale [VAS] scores), and disability (Neck Disability Index [NDI] and EQ-5D scores) were reviewed. Multivariate analysis was used.
A total of 186 patients were included, and 48.4% were male. Their mean age was 55.4 years, and 45.7% had myelopathy. Preoperative cervical sagittal vertical axis (cSVA), cervical lordosis (CL), and T1 slope values were 24.9 mm (range 0–55 mm), 10.4° (range −6.0° to 44°), and 28.3° (range 14.0°–51.0°), respectively. ACDF was performed at 1, 2, and 3 levels in 47.8%, 42.0%, and 10.2% of patients, respectively. Preoperative neck and arm VAS scores were 5.7 and 5.4, respectively. NDI and EQ-5D scores were 22.1 and 0.5, respectively. There was significant improvement in all outcomes at 3 months (p < 0.001) and 12 months (p < 0.001). At 3 months, neck VAS (3.0), arm VAS (2.2), NDI (12.7), and EQ-5D (0.7) scores were improved, and at 12 months, neck VAS (2.8), arm VAS (2.3), NDI (11.7), and EQ-5D (0.8) score improvements were sustained. Improvements occurred within the first 3-month period; there was no significant difference in outcomes between the 3-month and 12-month mark. There was no correlation among cSVA, CL, or T1 slope with any outcome endpoint. The most consistent independent preoperative factors associated with worse outcomes were high neck and arm VAS scores and a severe NDI result (p < 0.001). Similar findings were seen with worse NDI and EQ-5D scores (p < 0.001). A significant linear trend of worse NDI and EQ-5D scores at 3 and 12 months was associated with worse baseline scores. Of the 186 patients, 171 (91.9%) had 3-month follow-up data, and 162 (87.1%) had 12-month follow-up data.
ACDF is effective in improving pain and disability, and improvement occurs within 3 months of surgery. cSVA, CL, and T1 slope do not appear to influence outcomes following ACDF surgery in the population with degenerative cervical disease. Therefore, in patients with relatively normal cervical parameters, augmenting alignment or lordosis is likely unnecessary. Worse preoperative pain and disability were independently associated with worse outcomes.
The MISDEF2 algorithm: an updated algorithm for patient selection in minimally invasive deformity surgery
Praveen V. Mummaneni, Paul Park, Christopher I. Shaffrey, Michael Y. Wang, Juan S. Uribe, Richard G. Fessler, Dean Chou, Adam S. Kanter, David O. Okonkwo, Gregory M. Mundis Jr., Robert K. Eastlack, Pierce D. Nunley, Neel Anand, Michael S. Virk, Lawrence G. Lenke, Khoi D. Than, Leslie C. Robinson, Kai-Ming Fu, and the International Spine Study Group (ISSG)
Minimally invasive surgery (MIS) can be used as an alternative or adjunct to traditional open techniques for the treatment of patients with adult spinal deformity. Recent advances in MIS techniques, including advanced anterior approaches, have increased the range of candidates for MIS deformity surgery. The minimally invasive spinal deformity surgery (MISDEF2) algorithm was created to provide an updated framework for decision-making when considering MIS techniques in correction of adult spinal deformity.
A modified algorithm was developed that incorporates a patient’s preoperative radiographic parameters and leads to one of 4 general plans ranging from basic to advanced MIS techniques to open deformity surgery with osteotomies. The authors surveyed 14 fellowship-trained spine surgeons experienced with spinal deformity surgery to validate the algorithm using a set of 24 cases to establish interobserver reliability. They then re-surveyed the same surgeons 2 months later with the same cases presented in a different sequence to establish intraobserver reliability. Responses were collected and analyzed. Correlation values were determined using SPSS software.
Over a 3-month period, 14 fellowship-trained deformity surgeons completed the surveys. Responses for MISDEF2 algorithm case review demonstrated an interobserver kappa of 0.85 for the first round of surveys and an interobserver kappa of 0.82 for the second round of surveys, consistent with substantial agreement. In at least 7 cases, there was perfect agreement between the reviewing surgeons. The mean intraobserver kappa for the 2 surveys was 0.8.
The MISDEF2 algorithm was found to have substantial inter- and intraobserver agreement. The MISDEF2 algorithm incorporates recent advances in MIS surgery. The use of the MISDEF2 algorithm provides reliable guidance for surgeons who are considering either an MIS or an open approach for the treatment of patients with adult spinal deformity.
Laminectomy alone versus fusion for grade 1 lumbar spondylolisthesis in 426 patients from the prospective Quality Outcomes Database
Andrew K. Chan, Erica F. Bisson, Mohamad Bydon, Steven D. Glassman, Kevin T. Foley, Eric A. Potts, Christopher I. Shaffrey, Mark E. Shaffrey, Domagoj Coric, John J. Knightly, Paul Park, Michael Y. Wang, Kai-Ming Fu, Jonathan R. Slotkin, Anthony L. Asher, Michael S. Virk, Panagiotis Kerezoudis, Silky Chotai, Anthony M. DiGiorgio, Regis W. Haid, and Praveen V. Mummaneni
The AANS launched the Quality Outcomes Database (QOD), a prospective longitudinal registry that includes demographic, clinical, and patient-reported outcome (PRO) data to measure the safety and quality of spine surgery. Registry data offer “real-world” insights into the utility of spinal fusion and decompression surgery for lumbar spondylolisthesis. Using the QOD, the authors compared the initial 12-month outcome data for patients undergoing fusion and those undergoing laminectomy alone for grade 1 degenerative lumbar spondylolisthesis.
Data from 12 top enrolling sites were analyzed and 426 patients undergoing elective single-level spine surgery for degenerative grade 1 lumbar spondylolisthesis were found. Baseline, 3-month, and 12-month follow-up data were collected and compared, including baseline clinical characteristics, readmission rates, reoperation rates, and PROs. The PROs included Oswestry Disability Index (ODI), back and leg pain numeric rating scale (NRS) scores, and EuroQol–5 Dimensions health survey (EQ-5D) results.
A total of 342 (80.3%) patients underwent fusion, with the remaining 84 (19.7%) undergoing decompression alone. The fusion cohort was younger (60.7 vs 69.9 years, p < 0.001), had a higher mean body mass index (31.0 vs 28.4, p < 0.001), and had a greater proportion of patients with back pain as a major component of their initial presentation (88.0% vs 60.7%, p < 0.001). There were no differences in 12-month reoperation rate (4.4% vs 6.0%, p = 0.93) and 3-month readmission rates (3.5% vs 1.2%, p = 0.45). At 12 months, both cohorts improved significantly with regard to ODI, NRS back and leg pain, and EQ-5D (p < 0.001, all comparisons). In adjusted analysis, fusion procedures were associated with superior 12-month ODI (β −4.79, 95% CI −9.28 to −0.31; p = 0.04).
Surgery for grade 1 lumbar spondylolisthesis—regardless of treatment strategy—was associated with significant improvements in disability, back and leg pain, and quality of life at 12 months. When adjusting for covariates, fusion surgery was associated with superior ODI at 12 months. Although fusion procedures were associated with a lower rate of reoperation, there was no statistically significant difference at 12 months. Further study must be undertaken to assess the durability of either surgical strategy in longer-term follow-up.
Open versus minimally invasive decompression for low-grade spondylolisthesis: analysis from the Quality Outcomes Database
Erica F. Bisson, Praveen V. Mummaneni, Michael S. Virk, John Knightly, Mohammed Ali Alvi, Anshit Goyal, Andrew K. Chan, Jian Guan, Steven Glassman, Kevin Foley, Jonathan R. Slotkin, Eric A. Potts, Mark E. Shaffrey, Christopher I. Shaffrey, Regis W. Haid Jr., Kai-Ming Fu, Michael Y. Wang, Paul Park, Anthony L. Asher, and Mohamad Bydon
Lumbar decompression without arthrodesis remains a potential treatment option for cases of low-grade spondylolisthesis (i.e., Meyerding grade I). Minimally invasive surgery (MIS) techniques have recently been increasingly used because of their touted benefits including lower operating time, blood loss, and length of stay. Herein, the authors analyzed patients enrolled in a national surgical registry and compared the baseline characteristics and postoperative clinical and patient-reported outcomes (PROs) between patients undergoing open versus MIS lumbar decompression.
The authors queried the Quality Outcomes Database for patients with grade I lumbar degenerative spondylolisthesis undergoing a surgical intervention between July 2014 and June 2016. Among more than 200 participating sites, the 12 with the highest enrollment of patients into the lumbar spine module came together to initiate a focused project to assess the impact of fusion on PROs in patients undergoing surgery for grade I lumbar spondylolisthesis. For the current study, only patients in this cohort from the 12 highest-enrolling sites who underwent a decompression alone were evaluated and classified as open or MIS (tubular decompression). Outcomes of interest included PROs at 2 years; perioperative outcomes such as blood loss and complications; and postoperative outcomes such as length of stay, discharge disposition, and reoperations.
A total of 140 patients undergoing decompression were selected, of whom 71 (50.7%) underwent MIS and 69 (49.3%) underwent an open decompression. On univariate analysis, the authors observed no significant differences between the 2 groups in terms of PROs at 2-year follow-up, including back pain, leg pain, Oswestry Disability Index score, EQ-5D score, and patient satisfaction. On multivariable analysis, compared to MIS, open decompression was associated with higher satisfaction (OR 7.5, 95% CI 2.41–23.2, p = 0.0005). Patients undergoing MIS decompression had a significantly shorter length of stay compared to the open group (0.68 days [SD 1.18] vs 1.83 days [SD 1.618], p < 0.001).
In this multiinstitutional prospective study, the authors found comparable PROs as well as clinical outcomes at 2 years between groups of patients undergoing open or MIS decompression for low-grade spondylolisthesis.
Differences in postoperative quality of life in young, early elderly, and late elderly patients undergoing surgical treatment for degenerative cervical myelopathy
Davide M. Croci, Brandon Sherrod, Mohammed Ali Alvi, Praveen V. Mummaneni, Andrew K. Chan, Mohamad Bydon, Steven D. Glassman, Kevin T. Foley, Eric A. Potts, Mark E. Shaffrey, Domagoj Coric, John J. Knightly, Paul Park, Michael Y. Wang, Kai-Ming Fu, Jonathan R. Slotkin, Anthony L. Asher, Khoi D. Than, Oren N. Gottfried, Christopher I. Shaffrey, Michael S. Virk, and Erica F. Bisson
Cervical spondylotic myelopathy (CSM) is a common progressive spine disorder affecting predominantly middle-aged and elderly populations. With increasing life expectancy, the incidence of CSM is expected to rise further. The outcomes of elderly patients undergoing CSM surgery and especially their quality of life (QOL) postoperatively remain undetermined. This study retrospectively reviewed patients to identify baseline differences and validated postoperative patient-reported outcome (PRO) measures in elderly patients undergoing CSM surgery.
The multi-institutional, neurosurgery-specific NeuroPoint Quality Outcomes Database was queried to identify CSM patients treated surgically at the 14 highest-volume sites from January 2016 to December 2018. Patients were divided into three groups: young (< 65 years), early elderly (65–74 years), and late elderly (≥ 75 years). Demographic and PRO measures (Neck Disability Index [NDI] score, modified Japanese Orthopaedic Association [mJOA] score, EQ-5D score, EQ-5D visual analog scale [VAS] score, arm pain VAS, and neck pain VAS) were compared among the groups at baseline and 3 and 12 months postoperatively.
A total of 1151 patients were identified: 691 patients (60%) in the young, 331 patients (28.7%) in the early elderly, and 129 patients (11.2%) in the late elderly groups. At baseline, younger patients presented with worse NDI scores (p < 0.001) and lower EQ-5D VAS (p = 0.004) and EQ-5D (p < 0.001) scores compared with early and late elderly patients. No differences among age groups were found in the mJOA score. An improvement of all QOL scores was noted in all age groups. On unadjusted analysis at 3 months, younger patients had greater improvement in arm pain VAS, NDI, and EQ-5D VAS compared with early and late elderly patients. At 12 months, the same changes were seen, but on adjusted analysis, there were no differences in PROs between the age groups.
The authors’ results indicate that elderly patients undergoing CSM surgery achieved QOL outcomes that were equivalent to those of younger patients at the 12-month follow-up.