Bone metastasis from glioblastoma: a systematic review.

INTRODUCTION: Glioblastoma (GBM) is a devastating disease with poor overall survival. Despite the common occurrence of GBM among primary brain tumors, metastatic disease is rare. Our goal was to perform a systematic literature review on GBM with osseous metastases and understand the rate of metastasis to the vertebral column as compared to the remainder of the skeleton, and how this histology would fit into our current paradigm of treatment for bone metastases. METHODS: A Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-compliant literature search was performed using the PubMed database from 1952 to 2021. Search terms included "GBM", "glioblastoma", "high-grade glioma", "bone metastasis", and "bone metastases". RESULTS: Of 659 studies initially identified, 67 articles were included in the current review. From these 67 articles, a total of 92 distinct patient case presentations of metastatic glioblastoma to bone were identified. Of these cases, 58 (63%) involved the vertebral column while the remainder involved lesions within the skull, sternum, rib cage, and appendicular skeleton. CONCLUSION: Metastatic dissemination of GBM to bone occurs. While the true incidence is unknown, workup for metastatic disease, especially involving the spinal column, is warranted in symptomatic patients. Lastly, management of patients with GBM vertebral column metastases can follow the International Spine Oncology Consortium two-step multidisciplinary algorithm for the management of spinal metastases.

The impact of age on approach-related complications with navigated lateral lumbar interbody fusion.

OBJECTIVE: Age is known to be a risk factor for increased complications due to surgery. However, elderly patients can gain significant quality-of-life benefits from surgery. Lateral lumbar interbody fusion (LLIF) is a minimally invasive procedure that is commonly used to treat degenerative spine disease. Recently, 3D navigation has been applied to LLIF. The purpose of this study was to determine whether there is an increased complication risk in the elderly with navigated LLIF. METHODS: Patients who underwent 3D-navigated LLIF for degenerative disease from 2014 to 2019 were included in the analysis. Patients were divided into elderly and nonelderly groups, with those 65 years and older categorized as elderly. Ninety-day medical and surgical complications were recorded. Patient and surgical characteristics were compared between groups, and multivariate regression analysis was used to determine independent risk factors for complication. RESULTS: Of the 115 patients included, 56 were elderly and 59 were nonelderly. There were 15 complications (25.4%) in the nonelderly group and 10 (17.9%) in the elderly group, which was not significantly different (p = 0.44). On multivariable analysis, age was not a risk factor for complication (p = 0.52). However, multiple-level LLIF was associated with an increased risk of approach-related complication (OR 3.58, p = 0.02). CONCLUSIONS: Elderly patients do not appear to experience higher rates of approach-related complications compared with nonelderly patients undergoing 3D navigated LLIF. Rather, multilevel surgery is a predictor for approach-related complication.

The feasibility of computer-assisted 3D navigation in multiple-level lateral lumbar interbody fusion in combination with posterior instrumentation for adult spinal deformity.

OBJECTIVE: The lateral lumbar interbody fusion (LLIF) technique is used to treat many common spinal degenerative pathologies including kyphoscoliosis. The use of spinal navigation for LLIF has not been broadly adopted, especially in adult spinal deformity. The purpose of this study was to evaluate the feasibility as well as the intraoperative and navigation-related complications of computer-assisted 3D navigation (CaN) during multiple-level LLIF for spinal deformity. METHODS: Retrospective analysis of clinical and operative characteristics was performed for all patients > 18 years of age who underwent multiple-level CaN LLIF combined with posterior instrumentation for adult spinal deformity at the University of Michigan between 2014 and 2020. Intraoperative CaN-related complications, LLIF approach-related postoperative complications, and medical postoperative complications were assessed. RESULTS: Fifty-nine patients were identified. The mean age was 66.3 years (range 42-83 years) and body mass index was 27.6 kg/m2 (range 18-43 kg/m2). The average coronal Cobb angle was 26.8° (range 3.6°-67.0°) and sagittal vertical axis was 6.3 cm (range -2.3 to 14.7 cm). The average number of LLIF and posterior instrumentation levels were 2.97 cages (range 2-5 cages) and 5.78 levels (range 3-14 levels), respectively. A total of 6 intraoperative complications related to the LLIF stage occurred in 5 patients. Three of these were CaN-related and occurred in 2 patients (3.4%), including 1 misplaced lateral interbody cage (0.6% of 175 total lateral cages placed) requiring intraoperative revision. No patient required a return to the operating room for a misplaced interbody cage. A total of 12 intraoperative complications related to the posterior stage occurred in 11 patients, with 5 being CaN-related and occurring in 4 patients (6.8%). Univariate and multivariate analyses revealed no statistically significant risk factors for intraoperative and CaN-related complications. Transient hip weakness and numbness were found to be in 20.3% and 22.0% of patients, respectively. At the 1-month follow-up, weakness was observed in 3.4% and numbness in 11.9% of patients. CONCLUSIONS: Use of CaN in multiple-level LLIF in the treatment of adult spinal deformity appears to be a safe and effective technique. The incidence of approach-related complications with CaN was 3.4% and cage placement accuracy was high.

Biomechanics of Cervical Disk Replacement: Classifying Arthroplasty Implants.

Cervical disk arthroplasty has been employed with increased frequency over the past 2 decades as a motion-preserving alternative to anterior cervical discectomy and fusion in select patients with myelopathy or radiculopathy secondary to degenerative disk disease. As indications continue to expand, an understanding of cervical kinematics and materials science is helpful for optimal implant selection. Cervical disk arthroplasty implants can be classified according to the mode of articulation and df , articulation material, and endplate construction. The incorporation of translational and rotational df allows the implant to emulate the dynamic and coupled centers of movement in the cervical spine. Durable and low-friction interfaces at the articulation sustain optimal performance and minimize particulate-induced tissue reactions. Endplate materials must facilitate osseous integration to ensure implant stability after primary fixation. These cardinal considerations underlie the design of the 9 implants currently approved by the FDA and serve as the foundation for further biomimetic research and development.

Syrinx regression after correction of iatrogenic kyphotic deformity: illustrative case.

BACKGROUND: Syringomyelia has a long-established association with pediatric scoliosis, but few data exist on the relationship of syringomyelia to pediatric kyphotic deformities. OBSERVATIONS: This report reviewed a unique case of rapid and sustained regression of syringomyelia in a 13-year-old girl after surgical correction of iatrogenic kyphotic deformity. LESSONS: In cases of syringomyelia associated with acquired spinal deformity, treatment of deformity to resolve an associated subarachnoid block should be considered because it may obviate the need for direct treatment of syrinx.

Navigated retrodiaphragmatic/retroperitoneal approach for the treatment of symptomatic kyphoscoliosis: an operative video.

Retropleural, retrodiaphragmatic, and retroperitoneal approaches are utilized to access difficult thoracolumbar junction (T10-L2) pathology. The authors present a 58-year-old man with chronic low-back pain who failed years of conservative therapy. Preoperative radiographs demonstrated significant levoconvex scoliosis with coronal and sagittal imbalance. He underwent a retrodiaphragmatic/retroperitoneal approach for T12-L1, L1-2, L2-3, and L3-4 interbody release and fusion in conjunction with second-stage facet osteotomies, L4-5 TLIF, and T10-iliac posterior instrumented fusion. This video focuses on the retrodiaphragmatic approach assisted by 3D navigation. The video can be found here: https://stream.cadmore.media/r10.3171/2022.3.FOCVID2215.

Correlation of the Modified Japanese Orthopedic Association With Functional and Quality-of-Life Outcomes After Surgery for Degenerative Cervical Myelopathy: A Quality Outcomes Database Study.

BACKGROUND: The modified Japanese Orthopedic Association (mJOA) score is a widely used and validated metric for assessing severity of myelopathy. Its relationship to functional and quality-of-life outcomes after surgery has not been fully described. OBJECTIVE: To quantify the association of the mJOA with the Neck Disability Index (NDI) and EuroQol-5 Dimension (EQ-5D) after surgery for degenerative cervical myelopathy. METHODS: The cervical module of the prospectively enrolled Quality Outcomes Database was queried retrospectively for adult patients who underwent single-stage degenerative cervical myelopathy surgery. The mJOA score, NDI, and EQ-5D were assessed preoperatively and 3 and 12 months postoperatively. Improvement in mJOA was used as the independent variable in univariate and multivariable linear and logistic regression models. RESULTS: Across 14 centers, 1121 patients were identified, mean age 60.6 ± 11.8 years, and 52.5% male. Anterior-only operations were performed in 772 patients (68.9%). By univariate linear regression, improvements in mJOA were associated with improvements in NDI and EQ-5D at 3 and 12 months postoperatively (all P < .0001) and with improvements in the 10 NDI items individually. These findings were similar in multivariable regression incorporating potential confounders. The Pearson correlation coefficients for changes in mJOA with changes in NDI were -0.31 and -0.38 at 3 and 12 months postoperatively. The Pearson correlation coefficients for changes in mJOA with changes in EQ-5D were 0.29 and 0.34 at 3 and 12 months. CONCLUSION: Improvements in mJOA correlated weakly with improvements in NDI and EQ-5D, suggesting that changes in mJOA may not be a suitable proxy for functional and quality-of-life outcomes.

Neurosurgery Subspecialty Practice During a Pandemic: A Multicenter Analysis of Operative Practice in 7 U.S. Neurosurgery Departments During Coronavirus Disease 2019.

OBJECTIVE: Changes to neurosurgical practices during the coronavirus disease 2019 (COVID-19) pandemic have not been thoroughly analyzed. We report the effects of operative restrictions imposed under variable local COVID-19 infection rates and health care policies using a retrospective multicenter cohort study and highlight shifts in operative volumes and subspecialty practice. METHODS: Seven academic neurosurgery departments' neurosurgical case logs were collected; procedures in April 2020 (COVID-19 surge) and April 2019 (historical control) were analyzed overall and by 6 subspecialties. Patient acuity, surgical scheduling policies, and local surge levels were assessed. RESULTS: Operative volume during the COVID-19 surge decreased 58.5% from the previous year (602 vs. 1449, P = 0.001). COVID-19 infection rates within departments' counties correlated with decreased operative volume (r = 0.695, P = 0.04) and increased patient categorical acuity (P = 0.001). Spine procedure volume decreased by 63.9% (220 vs. 609, P = 0.002), for a significantly smaller proportion of overall practice during the COVID-19 surge (36.5%) versus the control period (42.0%) (P = 0.02). Vascular volume decreased by 39.5% (72 vs. 119, P = 0.01) but increased as a percentage of caseload (8.2% in 2019 vs. 12.0% in 2020, P = 0.04). Neuro-oncology procedure volume decreased by 45.5% (174 vs. 318, P = 0.04) but maintained a consistent proportion of all neurosurgeries (28.9% in 2020 vs. 21.9% in 2019, P = 0.09). Functional neurosurgery volume, which declined by 81.4% (41 vs. 220, P = 0.008), represented only 6.8% of cases during the pandemic versus 15.2% in 2019 (P = 0.02). CONCLUSIONS: Operative restrictions during the COVID-19 surge led to distinct shifts in neurosurgical practice, and local infective burden played a significant role in operative volume and patient acuity.

Cervical 1-2 Posterior Instrumented Fusion Utilizing Computer-Assisted Navigation With Harvest of Rib Strut Autograft: 2-Dimensional Operative Video.

Nonunion of a type II odontoid fracture after the placement of an anterior odontoid screw can occur despite careful patient selection. Countervailing factors to successful fusion include the vascular watershed zone between the odontoid process and body of C2 as well as the relatively low surface area available for fusion. Patient-specific factors include osteoporosis, advanced age, and poor fracture fragment apposition. Cervical 1-2 posterior instrumented fusion is indicated for symptomatic nonunion. The technique leverages the larger posterolateral surface area for fusion and does not rely on bony growth in a watershed zone. Although loss of up to half of cervical rotation is expected after C1-2 arthrodesis, this may be better tolerated in the elderly, who may have lower physical demands than younger patients. In this video, we discuss the case of a 75-yr-old woman presenting with intractable mechanical cervicalgia 7 mo after sustaining a type II odontoid fracture and undergoing anterior odontoid screw placement at an outside institution. Cervical radiography and computed tomography exhibited haloing around the screw and nonunion across the fracture. We demonstrate C1-2 posterior instrumented fusion with Goel-Harms technique (C1 lateral mass and C2 pedicle screws), utilizing computer-assisted navigation, and modified Sonntag technique with rib strut autograft. Posterior C1-2-instrumented fusion with rib strut autograft is an essential technique in the spine surgeon's armamentarium for the management of C1-2 instability, which can be a sequela of type II dens fracture. Detailed video demonstration has not been published to date. Appropriate patient consent was obtained.

Spinal arthrodesis via lumbar interbody fusion without direct decompression as a treatment for recurrent radicular pain due to epidural fibrosis: patient series.

BACKGROUND: Lumbar radiculopathy is the most common indication for lumbar discectomy, but residual postoperative radicular symptoms are common. Postoperative lumbar radiculopathy secondary to scar formation is notoriously difficult to manage, with the mainstay of treatment focused on nonoperative techniques. Surgical intervention for epidural fibrosis has shown unacceptably high complication rates and poor success rates. OBSERVATIONS: Three patients underwent spinal arthrodesis without direct decompression for recurrent radiculopathy due to epidural fibrosis. Each patient previously underwent lumbar discectomy but subsequently developed recurrent radiculopathy. Imaging revealed no recurrent disc herniation, although it demonstrated extensive epidural fibrosis and scar in the region of the nerve root at the previous surgical site. Dynamic radiographs showed no instability. Two patients underwent lateral lumbar interbody fusion, and one patient underwent anterior lumbosacral interbody fusion. Each patient experienced resolution of radicular symptoms by the 1-year follow-up. Average EQ visual analog scale scores improved from 65 preoperatively to 78 postoperatively. LESSONS: Spinal arthrodesis via lumbar interbody fusion, without direct decompression, may relieve pain in patients with recurrent radiculopathy due to epidural fibrosis, even in the absence of gross spinal instability.

Navigation and Robotic-Assisted Single-Position Prone Lateral Lumbar Interbody Fusion: Technique, Feasibility, Safety, and Case Series.

BACKGROUND: Single-position prone lateral interbody fusion is a recently introduced technical modification of the minimally invasive retroperitoneal transpsoas approach for lateral lumbar interbody fusion (LLIF). Several technical descriptions of single-position prone LLIF have been published with traditional fluoroscopy for guidance. However, there has been no investigation of either three-dimensional computed tomography-based navigation for prone LLIF or integration with robotic assistance platforms with the prone lateral technique. This study evaluated the feasibility and safety of spinal navigation and robotic assistance for single-position prone LLIF. METHODS: Retrospective review of medical records and a prospectively acquired database for a single center was performed to examine immediate and 30-day clinical and radiographic outcomes for consecutive patients undergoing single-position prone LLIF with spinal navigation and/or robotic assistance. RESULTS: Nine patients were treated, 4 women and 5 men. Mean age was 65.4 years (range, 46-75 years), and body mass index was 30.2 kg/m2 (range, 24-38 kg/m2). The most common surgical indication was adjacent segment disease (44.4%), followed by pseudarthrosis (22.2%), spondylolisthesis (11.1%), degenerative disc disease (11.1%), and recurrent stenosis (11.1%). Postoperative approach-related complications included pain-limited bilateral hip flexor weakness (4/5) and pain-limited left knee extension weakness (4/5) in 1 patient (11.1%) and right lateral thigh numbness and dysesthesia in 1 patient (11.1%). All cages were placed within quarters 2-3, signifying the middle portion of the disc space. There were no instances of misguidance by navigation. CONCLUSIONS: Integration of spinal navigation and robotic assistance appears feasible, accurate, and safe as an alternative to fluoroscopic guidance for single-position LLIF.

Resection of a Lumbar Intradural Extramedullary Schwannoma: 2-Dimensional Operative Video.

Schwannomas are typically benign tumors that arise from the sheaths of nerves in the peripheral nervous system. In the spine, schwannomas usually arise from spinal nerve roots and are therefore extramedullary in nature. Surgical resection-achieving a gross total resection, is the main treatment modality and is typically curative for patients with sporadic tumors. In this video, we present the case of a 38-yr-old male with worsening left leg radiculopathy, found to have a lumbar schwannoma. Preoperative imaging demonstrated that the tumor was at the level of L4-L5. A laminectomy at this level was performed with gross total resection of the tumor. The key points of the video include use of intraoperative fluoroscopy to confirm surgical level and help plan surgical exposure, use of ultrasound for intradural tumor localization, and advocating for maximum safe resection using neurostimulation. The patient tolerated the surgery well without any complications. He was discharged home with no additional therapy needed. Appropriate patient consent was obtained.

Lumbar Laminoplasty for Resection of Myxopapillary Ependymoma of the Conus Medullaris: 2-Dimensional Operative Video.

Myxopapillary ependymomas are slow-growing tumors that are located almost exclusively in the region of the conus medullaris, cauda equina, and filum terminale of the spinal cord. Surgical intervention achieving a gross total resection is the main treatment modality. If, however, a gross total resection cannot be achieved, surgery is augmented with radiation therapy. In this video, we present the case of a 27-yr-old male with persistent back pain and radiculopathy who was found to have a myxopapillary ependymoma that was adherent to the conus. Preoperative imaging demonstrated that the tumor was displacing the conus and nerve roots ventrally. A laminoplasty at L1-L2 was performed with near-total resection because of the intimate involvement of neural tissue. The key features of the video include performing laminoplasty and rationale, and performing maximum safe tumor resection with a combination of bipolar cautery, suction, and ultrasonic aspiration augmented with frequent stimulation, gel foam pledgets intradurally, and achieving a watertight closure of the dura and fascia. The patient tolerated the surgery well without any complications. Given his gross residual disease along the conus and young age, he was at a high risk for continued tumor growth without adjuvant therapy, with a recurrence rate of roughly 33% to 45% in patients who underwent subtotal resection. With the addition of adjuvant radiation therapy, the recurrence rate is 20% to 29%.1,2 He was discharged to home with a plan for conventional fractionated external beam radiation. At the most recent follow-up, he reported decreased back pain and radiculopathy. Appropriate patient consent was obtained.

Survival, fusion, and hardware failure after surgery for spinal metastatic disease.

OBJECTIVE: Decompression with instrumented fusion is commonly employed for spinal metastatic disease. Arthrodesis is typically sought despite limited knowledge of fusion outcomes, high procedural morbidity, and poor prognosis. This study aimed to describe survival, fusion, and hardware failure after decompression and fusion for spinal metastatic disease. METHODS: The authors retrospectively examined a prospectively collected, single-institution database of adult patients undergoing decompression and instrumented fusion for spinal metastases. Patients were followed clinically until death or loss to follow-up. Fusion was assessed using CT when performed for oncological surveillance at 6-month intervals through 24 months postoperatively. Estimated cumulative incidences for fusion and hardware failure accounted for the competing risk of death. Potential risk factors were analyzed with univariate Fine and Gray proportional subdistribution hazard models. RESULTS: One hundred sixty-four patients were identified. The mean age ± SD was 62.2 ± 10.8 years, 61.6% of patients were male, 98.8% received allograft and/or autograft, and 89.6% received postoperative radiotherapy. The Kaplan-Meier estimate of median survival was 11.0 months (IQR 3.5-37.8 months). The estimated cumulative incidences of any fusion and of complete fusion were 28.8% (95% CI 21.3%-36.7%) and 8.2% (95% CI 4.1%-13.9%). Of patients surviving 6 and 12 months, complete fusion was observed in 12.5% and 16.1%, respectively. The estimated cumulative incidence of hardware failure was 4.2% (95% CI 1.5-9.3%). Increasing age predicted hardware failure (HR 1.2, p = 0.003). CONCLUSIONS: Low rates of complete fusion and hardware failure were observed due to the high competing risk of death. Further prospective, case-control studies incorporating nonfusion instrumentation techniques may be warranted.

Complications of anterior cervical spine surgery: a systematic review of the literature.

The anterior approach to the cervical spine is commonly utilized for a variety of degenerative, traumatic, neoplastic, and infectious indications. While many potential complications overlap with those of the posterior approach, the distinct anatomy of the anterior neck also presents a unique set of hazards. We performed a systematic review of the literature to assess the etiology, presentation, natural history, and management of these complications. Following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), a PubMed search was conducted to evaluate clinical studies and case reports of patients who suffered a complication of anterior cervical spine surgery. The search specifically included articles concerning adult human subjects, written in the English language, and published from 1989 to 2019. The PubMed search yielded 240 articles meeting our criteria. The overall rates of complications were as follows: dysphagia 5.3%, esophageal perforation 0.2%, recurrent laryngeal nerve palsy 1.3%, infection 1.2%, adjacent segment disease 8.1%, pseudarthrosis 2.0%, graft or hardware failure 2.1%, cerebrospinal fluid leak 0.5%, hematoma 1.0%, Horner syndrome 0.4%, C5 palsy 3.0%, vertebral artery injury 0.4%, and new or worsening neurological deficit 0.5%. Morbidity rates in anterior cervical spine surgery are low. Nevertheless, the unique anatomy of the anterior neck presents a wide variety of potential complications involving vascular, aerodigestive, neural, and osseous structures.

Three-Dimensional Navigated Lateral Lumbar Interbody Fusion: 2-Dimensional Operative Video.

Spondylolisthesis is a common cause of lower back and leg pain in adults. The initial treatment for patients is typically nonoperative in nature. However, when patients fail conservative management and their back and/or leg pain is recalcitrant, surgical intervention is warranted. Spinal decompression, either directly or indirectly, as well as fusion is often considered at this point. There are numerous approaches to fuse the spine, including anterior, lateral, or posterior, each with their own advantages and disadvantages. This video illustrates a case of symptomatic spondylolisthesis occurring after laminectomy treated by lateral lumbar interbody fusion for indirect decompression and stabilization. The approach utilizes 3-dimensional navigation rather than traditional fluoroscopy, resulting in markedly decreased radiation exposure for the surgeon and staff while maintaining accuracy. Appropriate patient consent was obtained. This video demonstrates the technique for a lateral lumbar interbody fusion using navigation assistance, which is a minimally invasive technique for the treatment of spondylolisthesis.

Lumbar Lateral Recess Decompression: 2-Dimensional Operative Video.

Lateral recess stenosis is a common cause of lumbar radiculopathy in adults. A lumbar nerve root travels in the lateral recess prior to exiting the spinal canal via the neural foramen. In the lateral recess, the traversing nerve root is susceptible to compression by the degenerative hypertrophy of the medial facet in addition to hypertrophied ligamentum flavum and herniated intervertebral disc.1 These degenerative changes are also typically associated with neural foraminal stenosis. Surgical treatment in unilateral cases consists of hemilaminectomy, medial facetectomy, foraminotomy, and, if applicable, microdiscectomy. In this video, we present a case of a 64-yr-old male presenting with progressive left L5 radiculopathy refractory to conservative management, with magnetic resonance imaging (MRI) findings of left L4-5 foraminal and lateral recess stenosis. We demonstrate the operative steps to complete a left L4-5 hemilaminectomy, medial facetectomy, foraminotomy, and microdiscectomy. Appropriate patient consent was obtained.

Effect of Fenestrated Pedicle Screws with Cement Augmentation in Osteoporotic Patients Undergoing Spinal Fusion.

OBJECTIVE: Osteoporosis is a well-known risk factor for instrumentation failure and subsequent pseudoarthrosis after spinal fusion. In the present systematic review, we analyzed the biomechanical properties, clinical efficacy, and complications of cement augmentation via fenestrated pedicle screws in spinal fusion. METHODS: We conducted a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Reports appearing in the PubMed database up to March 31, 2020 were queried using the key words "cement," "pedicle screw," and "osteoporosis." We excluded non-English language studies, studies reported before 2000, studies that had involved use of cement without fenestrated pedicle screws, nonhuman studies, technical reports, and individual case reports. RESULTS: Twenty-five studies met the inclusion criteria. Eleven studies had tested the biomechanics of cement-augmented fenestrated pedicle screws. The magnitude of improvement achieved by cement augmentation of pedicle screws increased with the degree of osteoporosis. The cement-augmented fenestrated pedicle screw was superior biomechanically to the alternative "solid-fill" technique. Fourteen studies had evaluated complications. Cement extravasation with fenestrated screw usage was highly variable, ranging from 0% to 79.7%. However, cement extravasation was largely asymptomatic. Thirteen studies had assessed the outcomes. The use of cement-augmented fenestrated pedicles decreased screw pull out and improved fusion rates; however, the clinical outcomes were similar to those with traditional pedicle screw placement. CONCLUSIONS: The use of cement-augmented fenestrated pedicle screws can be an effective strategy for achieving improved pedicle screw fixation in patients with osteoporosis. A potential risk is cement extravasation; however, this complication will typically be asymptomatic. Larger comparative studies are needed to better delineate the clinical efficacy.

Correlation Between the Oswestry Disability Index and the North American Spine Surgery Patient Satisfaction Index.

BACKGROUND: The Oswestry Disability Index (ODI) is a widely used patient-reported outcome instrument in lumbar spine surgery, but its relationship to the increasingly scrutinized but still heterogeneous patient satisfaction metrics has not been well described. One popular metric is the North American Spine Society (NASS) patient satisfaction index. This study aimed to determine whether change in ODI predicts patient satisfaction. METHODS: Adult patients at a neurosurgery spine clinic completed the ODI and NASS questionnaires at various times in their care between September 2014 and November 2018. Scores were retrospectively analyzed using ordinal logistic regression. RESULTS: One thousand thirty-seven patients were identified (mean age 59.3 ± 14.7 years, 54.2% male). At 3, 12, and 24 months postoperatively, 684 (84.5%), 400 (83.3%), and 215 (80.9%) patients, respectively, expressed satisfaction (NASS score 1 or 2). Mean ± standard deviation improvements in ODI at 3, 12, and 24 months postoperatively were 16.8 ± 17.5 (n = 675), 18.4 ± 17.5 (n = 396), and 19.7 ± 17.7 (n = 213). For every unit improvement in ODI, the odds of selecting the next most satisfied NASS score at 3, 12, and 24 months postoperatively increased by 6.8% (95% confidence interval [CI] 5.6%-8.1%), 5.8% (95% CI 4.4%-7.1%), and 6.0% (95% CI 4.2%-7.9%), respectively. Every 10-unit improvement increased the odds, respectively, by 93.8% (95% CI 73.2%-117.0%), 75.0% (95% CI 53.8%-99.1%), and 79.4% (95% CI 50.3%-114.1%). CONCLUSIONS: Improvements in ODI are predictive of increased patient satisfaction as defined by the NASS index. A 10-point improvement in ODI nearly doubled the odds of increased satisfaction 3 months postoperatively.

Correlation between the Oswestry Disability Index and the 4-item short forms for physical function and pain interference from PROMIS.

OBJECTIVE: The Oswestry Disability Index (ODI) is one of the most commonly used patient-reported outcome instruments, but completion of this 10-question survey can be cumbersome. Tools from the Patient-Reported Outcomes Measurement Information System (PROMIS) are an alternative, and potentially more efficient, means of assessing physical, mental, and social outcomes in spine surgery. Authors of this retrospective study assessed whether scores on the 4-item surveys of function and pain from the PROMIS initiative correlate with those on the ODI in lumbar spine surgery. METHODS: Patients evaluated in the adult neurosurgery spine clinic at a single institution completed the ODI, PROMIS Short Form v2.0 Physical Function 4a (PROMIS PF), and PROMIS Short Form v1.0 Pain Interference 4a (PROMIS PI) at various time points in their care. Score data were retrospectively analyzed using linear regressions with calculation of the Pearson correlation coefficient. RESULTS: Three hundred forty-three sets of surveys (ODI, PROMIS PF, and PROMIS PI) were obtained from patients across initial visits (n = 147), 3-month follow-ups (n = 107), 12-month follow-ups (n = 52), and 24-month follow-ups (n = 37). ODI scores strongly correlated with PROMIS PF t-scores at baseline (r = -0.72, p < 0.0001), 3 months (r = -0.79, p < 0.0001), 12 months (r = -0.85, p < 0.0001), and 24 months (r = -0.89, p < 0.0001). ODI scores also correlated strongly with PROMIS PI t-scores at baseline (r = 0.71, p < 0.0001), at 3 months (r = 0.82, p < 0.0001), at 12 months (r = 0.86, p < 0.0001), and at 24 months (r = 0.88, p < 0.0001). Changes in ODI scores moderately correlated with changes in PROMIS PF t-scores (r = -0.68, p = 0.0003) and changes in PROMIS PI t-scores (r = 0.57, p = 0.0047) at 3 months postoperatively. CONCLUSIONS: A strong correlation was found between the ODI and the 4-item PROMIS PF/PI at isolated time points for patients undergoing lumbar spine surgery. Large cohort studies are needed to determine longitudinal accuracy and precision and to assess possible benefits of time savings and improved rates of survey completion.