Geometric analysis of pedicle subtraction osteotomy (PSO) for Kyphosis correction: anterior lengthening may occur at the osteotomized body as well as at the discs above and below.

OBJECTIVE: To validate the authors kyphosis correction formula for pedicle subtraction osteotomy (PSO) cases. Additionally, to use the formula to evaluate the safety of PSO by determining if there is anterior lengthening. METHODS: Twenty-two patients with primarily kyphosis corrected by PSO and with clear landmarks on preoperative and postoperative x-rays were selected. Several anatomical lines and angle measurements were utilized as depicted previously in the Vertebral Column Resection formula (see below). Two approximations were calculated: the geometric approximation (G) = (tanG°*2 + 1)*15° and the rough approximation (R) which is about the same amount of actual shortening (x), if parallel length (y) ≥ 40; twice of x, if y < 40. For each patient, the change of segmental kyphosis angle (K°) was measured and compared with G° and R°, and the correlation between each value was analyzed. RESULTS: The absolute Mean ± SE for K - G and K - R was 2.33° ± 0.34 and 6.09° ± 0.58, respectively. K - G is < 3° (p = 0.03). K - R is < 8° (p = 0.001). In other words, K was close to G and R and thus can be predicted by these approximations. Average posterior shortening, anterior shortening, and kyphosis correction at each level were 20.8 ± 2.0 mm, - 3.64 ± 1.5 mm (which equates to anterior lengthening), and 31.05° ± 2.0, respectively. Anterior lengthening occurred in 13 cases (in 4 cases, both at the body as well as at the disc above and below.) The correlation between posterior and anterior shortening was 0.03 (p = 0.88). There were 3 cage insertion cases: 1 had anterior lengthening, while 2 had anterior shortening even with the cage. CONCLUSION: This study validated the geometric and rough approximations originally used in PVCR patients, for PSO patients. Additionally, this study found that anterior lengthening may occur in PSOs usually at the discs, but occasionally at the osteotomized body.

Alvimopan for the reduction of postoperative ileus after long posterior spinal fusion: placebo-controlled double-blind randomized trial.

OBJECTIVE: The aim of this study was to evaluate the efficacy of alvimopan administration after posterior spinal fusion (PSF) in adult spine surgery patients who are taking opioid agents. METHODS: In this placebo-controlled, double-blind randomized trial, PSF patients were randomized in blocks to placebo or study drug. Primary and secondary outcome measures were return to normal bowel function, including time to passage of flatus and stool, time to tolerance of oral nutrition, and time to hospital discharge. Patients were included regardless of chronic opioid consumption status. RESULTS: Thirty-one patients provided consent for participation, and 26 patients (13 per group) completed the study. There were no differences between groups with respect to time to flatus, time to bowel movement, time to oral nutrition tolerance, and time to discharge. Calculated effect sizes favored placebo for all interventions. CONCLUSIONS: Alvimopan did not hasten return to bowel function for any primary or secondary outcome measures when compared with placebo for patients undergoing PSF. There were no adverse events related to alvimopan, including for patients with chronic opioid consumption. While underpowered to determine a statistical difference, it is unlikely that a clinically relevant effect exists.

Mechanosensitive transcriptional coactivators MRTF-A and YAP/TAZ regulate nucleus pulposus cell phenotype through cell shape.

Cells of the adult nucleus pulposus (NP) are critically important in maintaining overall disc health and function. NP cells reside in a soft, gelatinous matrix that dehydrates and becomes increasingly fibrotic with age. Such changes result in physical cues of matrix stiffness that may be potent regulators of NP cell phenotype and may contribute to a transition toward a senescent and fibroblastic NP cell with a limited capacity for repair. Here, we investigate the mechanosignaling cues generated from changes in matrix stiffness in directing NP cell phenotype and identify mechanisms that can potentially preserve a biosynthetically active, juvenile NP cell phenotype. Using a laminin-functionalized polyethylene glycol hydrogel, we show that when NP cells form rounded, multicell clusters, they are able to maintain cytosolic localization of myocardin-related transcription factor (MRTF)-A, a coactivator of serum-response factor (SRF), known to promote fibroblast-like behaviors in many cells. Upon preservation of a rounded shape, human NP cells similarly showed cytosolic retention of transcriptional coactivator Yes-associated protein (YAP) and its paralogue PDZ-binding motif (TAZ) with associated decline in activation of its transcription factor TEA domain family member-binding domain (TEAD). When changes in cell shape occur, leading to a more spread, fibrotic morphology associated with stronger F-actin alignment, SRF and TEAD are up-regulated. However, targeted deletion of either cofactor was not sufficient to overcome shape-mediated changes observed in transcriptional activation of SRF or TEAD. Findings show that substrate stiffness-induced promotion of F-actin alignment occurs concomitantly with a flattened, spread morphology, decreased NP marker expression, and reduced biosynthetic activity. This work indicates cell shape is a stronger indicator of SRF and TEAD mechanosignaling pathways than coactivators MRTF-A and YAP/TAZ, respectively, and may play a role in the degeneration-associated loss of NP cellularity and phenotype.-Fearing, B. V., Jing, L., Barcellona, M. N., Witte, S. E., Buchowski, J. M., Zebala, L. P., Kelly, M. P., Luhmann, S., Gupta, M. C., Pathak, A., Setton, L. A. Mechanosensitive transcriptional coactivators MRTF-A and YAP/TAZ regulate nucleus pulposus cell phenotype through cell shape.

PROMIS correlation with NDI and VAS measurements of physical function and pain in surgical patients with cervical disc herniations and radiculopathy.

OBJECTIVE: The aim of this study was to compare the patient-reported outcome measures Neck Disability Index (NDI) and visual analog scale (VAS) with the Patient Reported Outcomes Measurement Information System (PROMIS) physical function (PF) and pain interference (PI) measures, respectively, and to determine their correlations in a surgical population longitudinally.Legacy outcome measures such as NDI and VAS are essential for analyzing treatments in spine surgery for cervical disc herniations with radiculopathy. Despite their usefulness, administrative burdens impose limits on completion of these measures. PROMIS was developed as a patient outcome measure in order to improve reporting of patient symptoms and function and to reduce administrative burden. Despite early positive results of PROMIS in orthopedics, NDI and VAS scores have not been compared with PROMIS scores in patients with cervical disc herniations with radiculopathy. METHODS: Eighty patients undergoing surgery for cervical disc herniations with radiculopathy were included. All patients were treated at the same tertiary spine center. Patients were seen and PROMIS PF and PI, NDI, and VAS arm and neck pain scores were collected preoperatively and at 1 year postoperatively. Correlations between NDI, VAS, and PROMIS PF and PI were quantified using Pearson correlation coefficients. Two-tailed Student t-tests were used to demonstrate correlation significance, with alpha = 0.05. RESULTS: All 80 (100%) patients completed all preoperative questionnaires. Fifty-seven (72%) and 75 (94%) patients completed all questionnaires at baseline and at the 6-month and 1-year follow-ups, respectively. PROMIS PF and NDI scores demonstrated a strong negative correlation, with Pearson r values of -0.81, -0.77, and -0.75 at baseline, 6 months, and 1 year. PROMIS PI and VAS neck pain scores demonstrated a moderately positive correlation, with Pearson r values of 0.51, 0.61, and 0.6. PROMIS PI and VAS arm pain scores demonstrated a moderately positive correlation, with Pearson r values of 0.46, 0.47, and 0.45. CONCLUSIONS: PROMIS PF scores have a strong negative correlation with NDI scores at baseline and in the postoperative course in patients undergoing surgery for cervical disc herniations with radiculopathy. PROMIS PI scores have a moderately positive correlation with VAS neck and arm pain scores at baseline and in the postoperative course. Surgeons may factor these correlation results into the interpretation of patient-reported outcome measures in patients with cervical radiculopathy. Use of PROMIS PF and PI for this patient population may reduce administrative burden while providing reliable outcomes data.

Reliability of the Neck Disability Index and Japanese Orthopedic Association questionnaires in adult cervical radiculopathy and myelopathy patients when administered by telephone or via online format.

BACKGROUND: The internal validity of long-term studies is significantly affected by the high loss to follow-up in the spine surgery population (>20%). Phone and email-based administration of patient-reported outcomes instruments is a less cumbersome approach for increasing response rates and assessment frequency while potentially decreasing follow-up burden on patients and physicians. PURPOSE: This study sought to validate simultaneous administration of the Neck Disability Index (NDI) and Japanese Orthopedic Association (JOA) questionnaires in patients with either cervical myelopathy and/or radiculopathy. STUDY DESIGN/SETTING: This is a single-center, randomized crossover phone and email validation of legacy outcome measures for cervical myelopathy and/or radiculopathy patients. PATIENT SAMPLE: The study included nonsurgical along with pre- and postsurgical cervical myelopathy and/or radiculopathy patients presenting to a tertiary spine care center. OUTCOME MEASURES: NDI and JOA. METHODS: Two-hundred and six patients (mean age: 58.5 years) were randomized in a 1:4 ratio to either email completion of the NDI and JOA before or after in-office completion, or to phone completion before or after in-office completion. An interval of 1 to 4 weeks was established between the administration of questionnaires. The difference between written in-office and corresponding email and phone versions was assessed with a paired t test. Homogeneity was assessed using intraclass correlation coefficients. Test-retest reliabilities were independently examined for postoperative patients (n=145). Recall bias was assessed in postoperative patients by calculating intraclass correlation coefficients for those with days between assessments lesser than the mean and for those greater. Differences in response rates between phone and email versions were assessed with McNemar's and Cochran-Mantel-Haenszel tests. RESULTS: There was no significant difference between email and in-office versions (n=85) of the NDI (p=.17, Mean Paired Difference=1.34) and JOA (p=.64, Mean Paired Difference=0.11). No significant difference was seen between phone followed by in-office administration (n=32) of the NDI (p=.88, Mean Paired Difference=0.22) and JOA (p=.38, Mean Paired Difference=-0.22), nor between in-office administration followed by phone (n=44) for the NDI (p=.10, Mean Paired Difference=2.79) and JOA (p=.37, Mean Paired Difference=0.27). Intraclass coefficients (ICCs) of the email versions of the NDI and JOA were 0.88 and 0.78, respectively; of the phone-before-office versions of the NDI and JOA were 0.91 and 0.82; of the office-before-phone versions were 0.86 and 0.78. Similarly, strong intraclass correlation coefficients indicative of a lack of recall bias were found for "In-Office" and external assessments completed by postsurgical patients with days between assessments lesser and greater than the mean (ICC range 0.63-0.92). No significant difference was seen in completion rates between email and in-office questionnaire completion (p=.13) and phone-before-office and in-office questionnaire completion (p=.31). However, a significant difference was found in completion rates for phone-after-office questionnaires (p<.001). CONCLUSIONS: Administration of the NDI and JOA over phone and email in patients with cervical myelopathy or radiculopathy is valid with strong test-retest reliability and internal consistency. Phone and email administration of the NDI and JOA can reduce nonresponse rates and decrease the burden of follow-up and data acquisition. Follow-up phone reminders increase the response rate for administration of these patient-reported outcomes (PROs) via email.

Operative Versus Nonoperative Treatment for Adult Symptomatic Lumbar Scoliosis.

BACKGROUND: The effectiveness of operative compared with nonoperative treatment at initial presentation (no prior fusion) for adult lumbar scoliosis has not, to our knowledge, been evaluated in controlled trials. The goals of this study were to evaluate the effects of operative and nonoperative treatment and to assess the benefits of these treatments to help treating physicians determine whether patients are better managed operatively or nonoperatively. METHODS: Patients with adult symptomatic lumbar scoliosis (aged 40 to 80 years, with a coronal Cobb angle measurement of ≥30° and an Oswestry Disability Index [ODI] score of ≥20 or Scoliosis Research Society [SRS]-22 score of ≤4.0) from 9 North American centers were enrolled in concurrent randomized or observational cohorts to evaluate operative versus nonoperative treatment. The primary outcomes were differences in the mean change from baseline in the SRS-22 subscore and ODI at 2-year follow-up. For the randomized cohort, the initial sample-size calculation estimated that 41 patients per group (82 total) would provide 80% power with alpha equal to 0.05, anticipating 10% loss to follow-up and 20% nonadherence in the nonoperative arm. However, an interim sample-size calculation estimated that 18 patients per group would be sufficient. RESULTS: Sixty-three patients were enrolled in the randomized cohort: 30 in the operative group and 33 in the nonoperative group. Two hundred and twenty-three patients were enrolled in the observational cohort: 112 in the operative group and 111 in the nonoperative group. The intention-to-treat analysis of the randomized cohort found that, at 2 years of follow-up, outcomes did not differ between the groups. Nonadherence was high in the randomized cohort (64% nonoperative-to-operative crossover). In the as-treated analysis of the randomized cohort, operative treatment was associated with greater improvement at the 2-year follow-up in the SRS-22 subscore (adjusted mean difference, 0.7 [95% confidence interval (CI), 0.5 to 1.0]) and in the ODI (adjusted mean difference, -16 [95% CI, -22 to -10]) (p < 0.001 for both). Surgery was also superior to nonoperative care in the observational cohort at 2 years after treatment on the basis of SRS-22 subscore and ODI outcomes (p < 0.001). In an overall responder analysis, more operative patients achieved improvement meeting or exceeding the minimal clinically important difference (MCID) in the SRS-22 subscore (85.7% versus 38.7%; p < 0.001) and the ODI (77.4% versus 38.3%; p < 0.001). Thirty-four revision surgeries were performed in 24 (14%) of the operative patients. CONCLUSIONS: On the basis of as-treated and MCID analyses, if a patient with adult symptomatic lumbar scoliosis is satisfied with current spine-related health, nonoperative treatment is advised, with the understanding that improvement is unlikely. If a patient is not satisfied with current spine health and expects improvement, surgery is preferred. LEVEL OF EVIDENCE: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Rod fracture in adult spinal deformity surgery fused to the sacrum: prevalence, risk factors, and impact on health-related quality of life in 526 patients.

BACKGROUND CONTEXT: Risk factors associated with rod fracture (RF) following adult spinal deformity (ASD) surgery fused to the sacrum remain debatable, and the impact of RF on patient-reported outcomes (PROs) after ASD surgery has not been investigated. PURPOSE: We aimed to evaluate the prevalence of and risk factors for RF and determine PROs changes associated with RF after ASD surgery fused to the sacrum. STUDY DESIGN/SETTING: A retrospective single-center cohort study was performed. PATIENT SAMPLE: Patients undergoing long-construct posterior spinal fusions to the sacrum performed at a single institution by two senior spine surgeons from 2004 to 2014 were included. OUTCOME MEASURES: Patient demographics, radiographic parameters, and surgical factors were assessed for risk factors associated with RF. Oswestry Disability Index (ODI) and Scoliosis Research Society-30 (SRS-30) scores were assessed at baseline, 1 year postoperatively, and latest follow-up. METHODS: Inclusion criteria were ASD patients age >18 who had ≥5 vertebrae instrumented and fused posteriorly to the sacrum and either development of RF or no development of RF with minimum 2-year follow-up. Patient characteristics, operative data, radiographic parameters, and PROs were analyzed at baseline and follow-up. Separate Cox proportional hazard models based on rod material and diameter were used to determine factors associated with RF. RESULTS: Five hundred twenty-six patients (80%) were available for analysis. RF occurred in 97 (18.4%) patients (unilateral RF n=61 [63%]; bilateral RF n=36 [37%]). Risk factors for fracture of 5.5 mm cobalt chromium (CC) instrumentation (CC 5.5 model) included preoperative sagittal vertical axis (hazard ratio [HR] 1.07, 95% confidence interval [95% CI] 1.02-1.14 per 1-cm increase), preoperative thoracolumbar kyphosis (HR 1.02, 95% CI 1.01-1.04 per 1-degree increase), and number of levels fused for patients who received rhBMP-2 <12 mg per level fused (HR 1.48, 95% CI 1.20-1.82 per 1-level increase). Implants that were 5.5-mm CC constructs were at a higher risk for fracture than 6.35-mm stainless steel (SS) constructs (HR 8.49, 95% CI 4.26-16.89). The RF group had less overall improvement in SRS Satisfaction (0.93 vs. 1.32; p=.007) and SRS Self-image domain scores (0.72 vs. 1.02; p=.01). The bilateral RF group had less overall improvement in ODI (8.1 vs. 15.8; p=.02), SRS Subscore (0.51 vs. 0.85; p=.03), and SRS Pain domain scores (0.48 vs. 0.95; p=.02) compared with the non-RF group at final follow-up. CONCLUSIONS: The prevalence of all RF after index procedures was 18.4%, 37% for bilateral RF. Greater preoperative sagittal vertical axis, greater preoperative thoracolumbar kyphosis, increased number of vertebrae fused for patients who received rhBMP-2 <12 mg per level fused, and CC 5.5-mm rod were associated with RF. Less improvement in patient satisfaction and self-image was noted in the RF group. Furthermore, bilateral RF significantly affected PROs as measured by ODI and SRS Subscore at final follow-up.

Dural Tears in Adult Deformity Surgery: Incidence, Risk Factors, and Outcomes.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: Describe the rate of dural tears (DTs) in adult spinal deformity (ASD) surgery. Describe the risk factors for DT and the impact of this complication on clinical outcomes. METHODS: Patients with ASD undergoing surgery between 2008 and 2014 were separated into DT and non-DT cohorts; demographics, operative details, radiographic, and clinical outcomes were compared. Statistical analysis included t tests or χ2 tests as appropriate and a multivariate analysis. RESULTS: A total of 564 patients were identified. The rate of DT was 10.8% (n = 61). Patients with DT were older (61.1 vs 56.5 years, P = .005) and were more likely to have had prior spine surgery (odds ratio [OR] = 2.0, 95% confidence interval [CI] = 1.2-3.3, P = .007). DT patients had higher pelvic tilt, lower lumbar lordosis, and greater pelvic-incidence lumbar lordosis mismatch than non-DT patients (P < .05). DT patients had longer operative times (424 vs 375 minutes, P = .008), were more likely to undergo interbody fusions (OR = 2.0, 95% CI = 1.1-3.6, P = .021), osteotomies (OR = 2.2, 95% CI = 1.1-4.0, P = .012), and decompressions (OR = 2.3, 95% CI = 1.3-4.3, P = .003). In our multivariate analysis, only decompressions were associated with an increased risk of DT (OR = 3.2, 95% CI = 1.4-7.6, P = .006). There were no significant differences in patient outcomes at 2 years. CONCLUSIONS: The rate of DT was 10.8% in an ASD cohort. This is similar to rates of DT reported following surgery for degenerative pathology. A history of prior spine surgery, decompression, interbody fusion, and osteotomies are all associated with an increased risk of DT, but decompression is the only independent risk factor for DT.

PROMIS Physical Function Correlation With NDI and mJOA in the Surgical Cervical Myelopathy Patient Population.

STUDY DESIGN: Retrospective review. OBJECTIVE: To determine the correlation of Patient-Reported Outcomes Measurement Information System (PROMIS) physical function with Neck Disability Index (NDI) and Modified Japanese Orthopedic Association (mJOA) scores in the surgical cervical myelopathy patient population. SUMMARY OF BACKGROUND DATA: Outcome measures such as NDI and mJOA are essential for analyzing treatments for cervical myelopathy. Administrative burdens impose limits on completion of these measures. The PROMIS group developed an outcome measure to improve reporting of patient symptoms and function and to reduce administrative burden. Despite early success, NDI and mJOA have not been compared with PROMIS in patients with cervical myelopathy. This study determines the correlation of NDI and mJOA with PROMIS in surgical patients with cervical myelopathy. METHODS: A total of 60 patients with cervical myelopathy undergoing surgery were included. PROMIS, NDI, and mJOA were collected preoperatively, and in the first 6 months postoperatively. Correlations between NDI, mJOA, and PROMIS were quantified using Pearson correlation coefficients. Students t tests were used to test significance. RESULTS: All 60 (100%) of patients completed preoperative questionnaires. Fifty-five (92%) of patients completed initial follow-up questionnaires within the first 6 months. PROMIS physical function and NDI demonstrated a strong negative correlation at baseline and in initial follow-up (R = -0.69, -0.76). PROMIS and mJOA demonstrated a strong positive correlation at baseline and in initial follow-up (R = 0.61, 0.72). CONCLUSION: PROMIS physical function has a strong negative correlation with NDI and a strong positive correlation with mJOA at baseline and in the early postoperative course in patients undergoing surgery for cervical myelopathy. Surgeons may factor these outcomes into the delivery and interpretation of patient-reported outcome measures in this population. Use of PROMIS may improve completion of outcome measures in the office and reduce administrative burden while still providing reliable outcomes data. LEVEL OF EVIDENCE: 3.

Comparison of transforaminal lumbar interbody fusion outcomes in patients receiving rhBMP-2 versus autograft.

BACKGROUND CONTEXT: Recombinant human bone morphogenetic protein 2 (rhBMP-2) plays a pivotal role in complex spine surgery. Despite its limited approval, the off-label use of rhBMP-2 is prevalent, particularly in transforaminal lumbar interbody fusions (TLIFs). PURPOSE: To determine the effectiveness and safety of rhBMP-2 use in TLIF procedures versus autograft. STUDY DESIGN: Retrospective cohort study. PATIENT SAMPLE: Patients older than 18 years undergoing spine surgery for lumbar degenerative spine disease at a single academic institution. OUTCOME MEASURES: Clinical outcome was determined according to patient records. Radiographic outcome was determined according to plain X-rays and computed tomography (CT). METHODS: A retrospective study from 1997 to 2014 was conducted on 191 adults undergoing anterior-posterior instrumented spinal fusion with TLIF at a single academic institution. Patient data were gathered from operative notes, follow-up clinic notes, and imaging studies to determine complications and fusion rates. One hundred eighty-seven patients fit the criteria, which included patients with a minimum of one TLIF, and had a minimum 2-year radiographic and clinical follow-up. Patients were further classified into a BMP group (n=83) or non-BMP group (n=104). Three logistic regression models were run using rhBMP-2 exposure as the independent variable. The respective outcome variables were TLIF-related complications (radiculitis, seroma, osteolysis, and ectopic bone), surgical complications, and all complications. RESULTS: Bone morphogenetic protein (n=83) and non-BMP (n=104) groups had similar baseline demographics (sex, diabetes, pre-existing cancer). On average, the BMP and non-BMP groups were similarly aged (51.9 vs. 47.9 years, p>.05), but the BMP group had a shorter follow-up time (3.03 vs. 4.06 years; p<.001) and fewer smokers (8 vs. 21 patients; p<.048). The fusion rate for the BMP and non-BMP groups was 92.7% and 92.3%, respectively. The pseudoarthrosis rate was 7.5% (14 of 187 patients). Radiculitis was observed in seven patients in the BMP group (8.4%) and two patients in the non-BMP group (1.9%). Seroma was observed in two patients in the BMP group (2.4%) and none in the non-BMP group. No deep infections were observed in the BMP group, and in one patient in the non-BMP group (0.96%). Although patients exposed to BMP were at a significantlygreater risk of developing radiculitis and seroma (odds ratio [OR]=4.53, confidence interval [CI]=1.42-14.5), BMP exposure was not a significant predictor of surgical complications (OR=0.32, CI=0.10-1.00) or overall complications (OR=1.11, CI=0.53-2.34). The outcome of TLIF-related complications was too rare and the confidence interval too wide for practical significance of the first model. CONCLUSION: Evidence supports the hypothesis that off-label use of rhBMP-2 in TLIF procedures is relatively effective for achieving bone fusion at rates similar to patients receiving autograft. Patients exhibited similar complication rates between the two groups, with the BMP group exhibiting slightly higher rates of radiculitis and seroma.

Development and Validation of a Novel Adult Spinal Deformity Surgical Invasiveness Score: Analysis of 464 Patients.

BACKGROUND: A surgical invasiveness index (SII) has been validated in general spine procedures but not adult spinal deformity (ASD). OBJECTIVE: To assess the ability of the SII to determine the invasiveness of ASD surgery and to create and validate a novel ASD index incorporating deformity-specific factors, which could serve as a standardized metric to compare outcomes and risk stratification of different ASD procedures for a given deformity. METHODS: Four hundred sixty-four patients who underwent ASD surgery between 2009 and 2012 were identified in 2 multicenter prospective registries. Multivariable models of estimated blood loss (EBL) and operative time were created using deformity-specific factors. Beta coefficients derived from these models were used to attribute points to each component. Scoring was iteratively refined to determine the R2 value of multivariate models of EBL and operative time using adult spinal deformity-surgical (ASD-S) as an independent variable. Similarly, we determined weighting of postoperative changes in radiographical parameters, which were incorporated into another index (adult spinal deformity-surgical and radiographical [ASD-SR]). The ability of these models to predict surgical invasiveness was assessed in a validation cohort. RESULTS: Each index was a significant, independent predictor of EBL and operative time (P < .001). On multivariate analysis, ASD-S and ASD-SR explained more variability in EBL and operative time than did the SII (P < .001). The ASD-SR explained 21% of the variation in EBL and 10% of the variation in operative time, whereas the SII explained 17% and 3.2%, respectively. CONCLUSION: The ASD-SR, which incorporates deformity-specific components, more accurately predicts the magnitude of ASD surgery than does the SII.

Fractional anisotropy to quantify cervical spondylotic myelopathy severity.

BACKGROUND: A number of clinical tools exist for measuring the severity of cervical spondylotic myelopathy (CSM). Several studies have recently described the use of non-invasive imaging biomarkers to assess severity of disease. These imaging markers may provide an additional tool to measure disease progression and represent a surrogate marker of response to therapy. Correlating these imaging biomarkers with clinical quantitative measures is critical for accurate therapeutic stratification and quantification of axonal injury. METHODS: Fourteen patients and seven healthy control subjects were enrolled. Patients were classified as mildly (7) or moderately (7) impaired based on Modified Japanese Orthopedic Association Scale. All patients underwent diffusion tensor imaging (DTI) and diffusion basis spectrum imaging (DBSI) analyses. In addition to standard neurological examination, all participants underwent 30-m Walking Test, 9-hole Peg Test (9HPT), grip strength, key pinch, and vibration sensation thresholds in the index finger and great toe. Differences in assessment scores between controls, mild and moderate CSM patients were correlated with DTI and DBSI derived fractional anisotropy (FA). RESULTS: Clinically, 30-meter walking times were significantly longer in the moderately impaired group than in the control group. Maximum 9HPT times were significantly longer in both the mildly and moderately impaired groups as compared to normal controls. Scores on great toe vibration sensation thresholds were lower in the mildly impaired and moderately impaired groups as compared to controls. We found no clear evidence for any differences in minimum grip strength, minimum key pinch, or index finger vibration sensation thresholds. There were moderately strong associations between DTI and DBSI FA values and 30-meter walking times and 9HPT. CONCLUSIONS: The 30-m Walking Test and 9HPT were both moderately to strongly associated with DTI/DBSI FA values. FA may represent an additional measure to help differentiate and stratify patients with mild or moderate CSM.

Impact of Depression on Patient-Reported Outcome Measures After Lumbar Spine Decompression.

STUDY DESIGN: A retrospective cohort study. OBJECTIVE: The aim of this study was to investigate the effect depression has on the improvement of patient-reported outcome measures (PROMs) following lumbar decompression. SUMMARY OF BACKGROUND DATA: Decompression without fusion is a viable treatment option for lumbar spine stenosis. Depression reportedly has a negative impact on PROMs after certain types of spine surgery, though verification of this with new, more precise outcome measures is needed. METHODS: We included consecutive adult patients who underwent lumbar decompression for lumbar spine stenosis between 2016 and 2017 who had PROM information system (PROMIS) physical function, pain, depression, and Oswestry Disability Index (ODI) questionnaires completed preoperatively and at 6-month follow-up. Patients with a PROMIS depression score >50 or <50 were allocated to the depressed and not depressed groups, respectively. The cohorts were compared using unpaired t tests and repeated-measures two-way analysis of variance (ANOVA) with statistical significance taken at P < 0.05. RESULTS: The analysis included 55 patients without depression and 56 patients with depression. Depressed patients had worse preoperative PROMIS physical function (30.08 vs. 36.66, P = 0.005), PROMIS pain (69.36 vs. 64.69, P < 0.0001), and ODI scores (51.92 vs. 36.35, P < 0.0001). Similarly, the depressed group had worse postoperative PROMIS physical function (36.29 vs. 40.34, P = 0.005), PROMIS pain (60.16 vs. 54.87, P < 0.0001), and ODI scores (37.01 vs. 23.44, P = 0.0003). We observed a statistically significant interaction between depression status and pre to postoperative improvement in outcome for PROMIS physical function (F[1,109] = 102.5, P < 0.0001) and depression scores (F[1,109] = 15.38, P = 0.0002). No interaction was found for pain and ODI scores. CONCLUSION: Our results suggest that depressed patients experience a greater magnitude of improvement in PROMIS physical function and depression scores than nondepressed patients. Despite this, depressed patients have worse postoperative outcomes for PROMIS physical function, depression, pain, and ODI. These findings are important for risk stratifying and treating depressed patients before lumbar spine decompression. LEVEL OF EVIDENCE: 3.

Can standard anterior Smith-Robinson supramanubrial approach be utilized for approach down to T2 or T3?

PURPOSE: The aim of this study was to determine a plain radiographic criterion for determining the feasibility of using the standard anterior Smith-Robinson supramanubrial approach for anterior surgery down to T2 or T3. METHODS: The surgical database (2002-2014) was searched to identify patients with anterior cervical surgery to T2 or T3. A method to determine whether a standard anterior Smith-Robinson approach can be used to operate on the upper thoracic levels was evaluated. The surgeon chose the surgical approach preoperatively using a lateral radiograph by determining if a line from the intended skin incision to the lower instrumented level (LIV) passed above the top of the manubrium. If so, a standard Smith-Robinson approach was selected. Another spine surgeon then analyzed all patients who had anterior thoracic fusion to T2 or below. The lateral radiographs were retrospectively reviewed. RESULTS: A total of 44 patients who underwent anterior surgery down to T2 or T3 vertebrae were identified. T2 was the LIV in 39 patients. T3 was the LIV in five patients. No surgery was abandoned or converted to a difference approach after making the standard Smith-Robinson approach. To increase visualization, T1 corpectomy was necessary in 4 of 39 patients when T2 was the LIV. T2 corpectomy was necessary in 2 of 5 patients when T3 was the LIV. CONCLUSION: If a line from the intended skin incision to the LIV passes over the top of the manubrium, a standard Smith-Robinson approach without sternotomy can be successfully used.

Perioperative Complications of Spinal Metastases Surgery.

The incidence of symptomatic spinal metastasis has increased due to treatment improvements and longer patient survival. More patients with spinal tumors are choosing operative treatment with an associated increased rate of perioperative complications. Operative metastatic disease treatment complication rates have also increased with overall rates ranging from 5.3% to 76.20%. The common surgical-related complications are iatrogenic dural injury and wound complications. The most common postoperative medical complications are delirium, pneumonia, and deep vein thrombosis. Risk factors for perioperative complications after spinal metastatic surgery include older age, multilevel of spinal metastases, preoperative irradiation, low preoperative Karnofsky Performance Score (10-40) and multiple comorbidities. Charlson Comorbidity Index and New England Spinal Metastasis Score were significant predictor of 30-day complications. The reoperation rate is 10.7%, and the reoperation is most commonly performed in the same admission. In addition, the 30-day mortality rate in this patient population is ∼7% (0.9%-13%) and is influenced by the type of cancer, disease burden, and patient comorbidities. We reviewed the prevalence and risk factors of common perioperative complications that occur with surgical treatment of metastatic spine disease, in an effort to guide the spine surgeon in anticipating and potentially avoiding these complications.

Preoperative Fiducial Marker Placement in the Thoracic Spine: A Technical Report.

STUDY DESIGN: A retrospective review. OBJECTIVE: The aim of this study was to demonstrate proof-of-concept of preoperative percutaneous intraosseous fiducial marker placement before thoracic spine surgery. SUMMARY OF BACKGROUND DATA: Wrong-level spine surgery is defined as a never event by Center for Medicare Services, yet the strength of data supporting the implementation of Universal Protocol to limit wrong level surgery is weak. The thoracic spine is especially prone to intraoperative mislocalization, particularly in cases of morbid obesity and anatomic variations. METHODS: We retrospectively reviewed all cases of preoperative percutaneous image-guided intraosseous placement of a metallic marker in the thoracic spine. Indications for surgery included degenerative disc disease (16/19), osteochondroma resection, spinal metastasis, and ligation of dural arteriovenous malformation. All metallic markers were placed from a percutaneous transpedicular approach under imaging guidance [fluoroscopy and computed tomography (CT) or CT alone]. Patient body mass index (BMI) was recorded. Overweight and obese BMI was defined greater than 25 and 30 kg/m, respectively. RESULTS: All 19 patients underwent fiducial marker placement and intraoperative localization successfully without complication. Twenty-two thoracic spine levels were localized. The T7, T9, T10, and T11 levels were the most often localized at rate of 18.1% for each level (4/22). The most cranial and caudal levels localized were T4 and T11. About 84.2% (16/19) of the cohort was overweight (57.9%; 11/19) or obese (26.3%; 5/19). The median BMI was 30.2 kg/m (range, 23.9-54.3 kg/m). CONCLUSION: Preoperative percutaneous thoracic fiducial marker placement under imaging guidance is a safe method for facilitating intraoperative localization of the target spinal level, especially in obese patients. Further studies are needed to quantify changes in operative time and radiation exposure. LEVEL OF EVIDENCE: 4.

Baseline Patient-Reported Outcomes Correlate Weakly With Radiographic Parameters: A Multicenter, Prospective NIH Adult Symptomatic Lumbar Scoliosis Study of 286 Patients.

STUDY DESIGN: Prospective, cross-sectional study. OBJECTIVE: The aim of the study was to determine which radiographic parameters drive patient-reported outcomes (PROs) in primary presentation adult symptomatic lumbar scoliosis (ASLS). SUMMARY OF BACKGROUND DATA: Previous literature suggests correlations between PROs and sagittal plane deformity (sagittal vertical axis [SVA], pelvic incidence-lumbar lordosis [PI-LL] mismatch, pelvic tilt [PT]). Prior work included revision and primary adult spinal deformity patients. The present study addresses only primary presentation ASLS. METHODS: Prospective baseline data were analyzed on 286 patients enrolled in an NIH RO1 clinical trial by nine centers from 2010 to 2014. INCLUSION CRITERIA: 40 to 80 years old, lumbar Cobb (LC) 30° or higher and Scoliosis Research Society-23 score 4.0 or less in Pain, Function or Self-Image domains, or Oswestry Disability Index (ODI) 20 or higher. Patients were primary presentation (no prior spinal deformity surgery) and had complete baseline data: standing coronal/sagittal 36" radiographs and PROs (ODI, Scoliosis Research Society-23, Short Form-12). Correlation coefficients were calculated to evaluate relations between radiographic parameters and PROs for the study population and a subset of patients with ODI 40 or higher. Analysis of variance was used to identify differences in PROs for radiographic modifier groups. RESULTS: Mean age was 60.3 years. Mean spinopelvic parameters were: LL = -39.2°; SVA = 3.1 cm; sacral slope = 32.5°; PT = 23.9°; PI-LL mismatch = 16.8°. Only weak correlations (0.2-0.4) were identified between population sacral slope, SVA and SVA modifiers, and SRS function. SVA and SVA modifiers were weakly associated with ODI. Although there were more correlations in subset analysis of high-symptom patients, all were weak. Analysis of variance identified significant differences in ODI reported by SVA modifier groups. CONCLUSION: In primary presentation patients with ASLS and a subset of "high-symptom" patients (ODI ≥ 40), only weak associations between baseline PROs and radiographic parameters were identified. For this patient population, these results suggest regional radiographic parameters (LC, LL, PT, PI-LL mismatch) are not drivers of PROs and cannot be used to extrapolate effect on patient-perceived pathology. LEVEL OF EVIDENCE: 2.

Granulomatosis with polyangiitis (Wegener's granulomatosis) causing atlantoaxial instability: a case report.

BACKGROUND CONTEXT: No previous cases of atlantoaxial instability due to granulomatosis with polyangiitis have been reported. PURPOSE: The aim of this study was to report a case of granulomatosis with polyangiitis causing atlantoaxial instability. STUDY DESIGN: This is a case report. PATIENT SAMPLE: A 45-year-old woman participated in this study. OUTCOME MEASURES: The patient's pain and atlantoaxial instability were resolved. METHODS: A 45-year-old Caucasian woman with a large ulcerative lesion in her oropharynx initially presented with chronic sinusitis, pharyngitis, and severe odynophagia. Years after her original symptoms began, she developed neck pain radiating into her upper trapezial region and shoulders. RESULTS: Atlantoaxial fusion was performed on the patient, resolving her neck, upper trapezial, and shoulder pain. She was diagnosed with granulomatosis with polyangiitis (formerly Wegener's granulomatosis) and treated with cyclophosphamide. CONCLUSIONS: Granulomatosis with polyangiitis should be part of the working differential diagnosis for non-traumatic cervical spine injury. The atlantoaxial instability can be managed with stabilization, and the disease process itself can be treated with cyclophosphamide.

Posterior Cervical Fusion With Recombinant Human Bone Morphogenetic Protein-2: Complications and Fusion Rate at Minimum 2-Year Follow-Up.

STUDY DESIGN: Retrospective case series. OBJECTIVE: The purpose of this study was to determine the fusion rate and evaluate the complications associated with the application of recombinant human bone morphogenetic protein-2 (rhBMP-2) in posterior cervical fusion. SUMMARY OF BACKGROUND DATA: The rates of fusion and complications associated with the use of rhBMP-2 in posterior cervical fusion is unclear, though recent work has shown up to a 100% fusion rate. METHODS: We independently reviewed consecutive series of patients who underwent posterior cervical, occipitocervical, or cervicothoracic instrumented fusion augmented with rhBMP-2. Two surgeons at a tertiary-referral, academic medical center performed all operations, and each patient had a minimum of 2-year follow-up. Fusion status was determined by bony bridging on computed tomography scans, absence of radiolucency around instrumentation, and absence of motion on lateral flexion/extension radiographs. RESULTS: Fifty-seven patients with a mean age of 56.7±13.2 years and mean follow-up of 37.7±20.6 months were analyzed. Forty-eight patients (84.2%) had undergone previous cervical surgery, and 42.1% had a preexisting nonunion. Constructs spanned 5.6±2.6 levels; 19.3% involved the occiput, whereas 61.4% crossed the cervicothoracic junction. The mean rhBMP-2 dose was 21.1±8.7 mg per operation. Iliac crest autograft was used for 29.8% of patients. Six patients (10.5%) experienced nonunion; only 2 required revision. In each case of nonunion, instrumentation crossed the occipitocervical or cervicothoracic junction. However, none of the analyzed variables was statistically associated with nonunion. Fourteen patients (24.6%) suffered complications, with 7 requiring additional surgery. CONCLUSIONS: The observed fusion rate of rhBMP-2-augmented posterior cervical, occipitocervical, and cervicothoracic fusions was 89.5%. This reflects the complicated nature of the patients included in the current study and demonstrates that rhBMP-2 cannot always overcome the biomechanical challenges entailed in spanning the occipitocervical or cervicothoracic junction.