How often does the preoperative plan for freehand pedicle screw placement match the actual surgical execution in adolescent idiopathic scoliosis?

PURPOSE: To provide a baseline for comparison with future advancements, this study determined the accuracy of preoperative planning of pedicle screw placement using standard radiographs for posterior fusion (PSF) for adolescent idiopathic scoliosis (AIS). METHODS: Ninety-five patients with AIS planned for PSF were prospectively enrolled. Preoperative planning was based upon standard upright posteroanterior and lateral radiographs. The planned number of screws to be placed at each level was recorded. Intraoperatively, all screws were placed by freehand technique. The number of successfully placed screws and the reasons for abandoning screw placement were documented. RESULTS: There were a total of 1783 pedicle screws planned preoperatively. The average planned implant density was 2.0 implants/vertebra. A total of 1723 (96.6%) of the planned screws were placed successfully. Fourteen (0.8%) screws were abandoned after attempted placement (range 0-2 screws/case). Of 241 screws planned in pedicles noted to be "hypoplastic," 13 resulted in the use of a hook or no instrumentation. The placement was not attempted for 49 (range 0-7/case) planned screws due to intraoperative decision-making and a sense that the curve was flexible enough not to require every screw. Three cases (3.2%) required instrumentation of an additional level. CONCLUSIONS: Standard spine radiographs allow for accurate preoperative planning for freehand pedicle screw placement in AIS. Ninety-seven percent of planned screws were placed successfully. The primary reason for deviation from the preoperative plan was intraoperative surgeon decision-making rather than difficulty with screw placement. This study will serve as a baseline when considering the utilization of navigation in PSF for AIS.

Selective thoracic fusion of a left decompensated main thoracic curve: proceed with caution?

PURPOSE: Previous research has shown that with certain idiopathic scoliosis curve types, performing a selective thoracic fusion (STF) is associated with an increased risk of coronal decompensation post-operatively. The purpose of the current study was to determine the influence of curve correction and fusion level on post-operative balance in STF for adolescent idiopathic scoliosis patients with pre-operative coronal decompensation. METHODS: A multicenter database was queried for subjects with right Lenke 1-4C curves, pre-operative left coronal imbalance, and 2-year follow-up who underwent STF (caudal fusion level of L1 or proximal). Rates of decompensation were compared between groups with different levels of fusion. Thoracic and lumbar curve correction as well as Scoliosis Research Society-22 outcome scores were compared between groups that were post-operatively balanced or persistently decompensated. RESULTS: 121 patients were identified with average thoracic and lumbar curves of 53° and 41°. Mean pre- and post-operative decompensations were 2.4 ± 1.0 and 1.8 ± 1.1 cm, respectively. Eighteen patients were fused short, 62 to, and 41 were fused past the stable vertebra. Ten patients were fused short, 32 to, and 78 were fused past the neutral vertebra. Incidence of post-operative decompensation was 41%. No differences in post-operative decompensation relative to the stable or neutral vertebra were noted (p = 0.66, p = 0.74). Post-operatively, those patients who were balanced had similar thoracic curve correction (58%) to those decompensated (54%, p = 0.11); however, patients balanced post-operatively had greater SLCC (45 vs 40%, p = 0.04). No differences in SRS-22 outcome scores were noted between groups (p > 0.05). CONCLUSIONS: There was a high rate of post-operative decompensation in patients with pre-operative coronal decompensation undergoing STF. Fusion to or past the stable or neutral vertebra did not affect the risk of persistent decompensation. Attempts to improve SLCC could reduce post-operative decompensation.

Can Internet information on vertebroplasty be a reliable means of patient self-education?

BACKGROUND: Studies of the quality and accuracy of health and medical information available on the Internet have shown that many sources provide inadequate information. However, to our knowledge, there are no published studies analyzing the quality of information available online regarding vertebroplasty. Because this has been a high-volume procedure with highly debated efficacy, it is critical that patients receive complete, accurate, and well-balanced information before deciding a treatment course. Additionally, few studies have evaluated the merit of academic site authorship or site certification on information quality, but some studies have used measurements of quality that are based primarily on subjective criteria or information accuracy rather than information completeness. QUESTIONS/PURPOSES: The purposes of our study were (1) to evaluate and analyze the information on vertebroplasty available to the general public through the Internet; (2) to see if sites sponsored by academic institutions offered a higher quality of information; and (3) to determine whether quality of information varied according to site approval by a certification body. METHODS: Three search engines were used to identify 105 web sites (35 per engine) offering information regarding vertebroplasty. Sites were evaluated for authorship/sponsorship, content, and references cited. Information quality was rated as "excellent," "high," "moderate," "low," or "unacceptable." Sites also were evaluated for contact information to set up an appointment. Data were analyzed as a complete set, then compared between authorship types, and finally evaluated by certification status. Academic sites were compared with other authorship groups and certified sites were compared with noncertified sites using Student's t-test. RESULTS: Appropriate indications were referenced in 74% of sites, whereas only 45% discussed a contraindication to the procedure. Benefits were expressed by 100% of sites, but risks were outlined in only 53% (p < 0.001). Ninety-nine percent of sites provided step-by-step descriptions of the procedure, and 44% of sites also included images. Alternative treatments were mentioned by 51% of sites. Twenty-seven percent of sites referenced peer-reviewed literature, 41% offered experiential or noncited data based on American populations, and 7% offered analogous data from international populations. Thirty percent of sites provided contact information for patient appointment scheduling. Seven percent of sites were classified as excellent quality, 6% as high quality, 11% as moderate quality, 19% as poor quality, and 57% as unacceptable. Sixteen percent of sites were sponsored by academic institutions, 62% by private groups, 8% by biomedical device companies, and 14% were sponsored otherwise. Academic sites reported fewer risks of the procedure than private sites or other sites (p = 0.05 and p = 0.04), but reported more risks than industry sites (p = 0.007). Academic sites were more likely than sites classified as other to offer contact information for patient appointment scheduling (p = 0.004). Nine percent of sites evaluated were Health on the Net Foundation (HONCode) certified. No association with improved information quality was observed in these sites relative to noncertified sites (all p > 0.05). CONCLUSIONS: Internet information regarding vertebroplasty is not only inadequate for proper patient education, but also potentially misleading as sites are more likely to present benefits of the procedure than risks. Although academic sites might be expected to offer higher-quality information than private, industry, or other sites, our data would suggest that they do not. HONCode certification cannot be used reliably as a means of qualifying website information quality. Academic sites should be expected to set a high standard and alter their Internet presence with adequate information distribution. Certification bodies also should alter their standards to necessitate provision of complete information in addition to emphasizing accurate information. Treating physicians may want to counsel their patients regarding the limitations of information present on the Internet and the pitfalls of current certification systems. LEVEL OF EVIDENCE: Level IV, economic and decision analyses. See the Instructions for Authors for a complete description of levels of evidence.

Lumbar Level Significantly Influences Postoperative Global Sagittal Balance Following Pedicle Subtraction Osteotomy.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: The current evidence regarding how level of lumbar pedicle subtraction osteotomy (PSO) influences correction of sagittal alignment is limited. This study sought to investigate the relationship of lumbar level and segmental angular change (SAC) of PSO with the magnitude of global sagittal alignment correction. METHODS: This study retrospectively evaluated 53 consecutive patients with adult spinal deformity who underwent lumbar PSO at a single institution. Radiographs were evaluated to quantify the effect of PSO on lumbar lordosis (LL), thoracic kyphosis (TK), sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), T1-spinopelvic inclination (T1SPI), T1-pelvic alignment (TPA), and sagittal vertical axis (SVA). RESULTS: Significant correlations were found between PSO SAC and the postoperative increase in LL (r = 0.316, P = .021) and PT (r = 0.352, P = .010), and a decrease in TPA (r = -0.324, P = .018). PSO level significantly correlated with change in T1SPI (r = -0.305, P = .026) and SVA (r = -0.406, P = .002), with more caudal PSO corresponding to a greater correction in sagittal balance. On multivariate analysis, more caudal PSO level independently predicted a greater reduction in T1SPI (ß = -3.138, P = .009) and SVA (ß = -29.030, P = .001), while larger PSO SAC (ß = -0.375, P = .045) and a greater number of fusion levels (ß = -1.427, P = .036) predicted a greater reduction in TPA. CONCLUSION: This study identified a gain of approximately 3 degrees and 3 cm of correction for each level of PSO more caudal to L1. Additionally, a larger PSO SAC predicted greater improvement in TPA. While further investigation of these relationships is warranted, these findings may help guide preoperative PSO level selection.

Preoperative Multifidus Muscle Quality is Associated With Patient Reported Outcomes After Lateral Lumbar Interbody Fusion.

STUDY DESIGN: Retrospective cohort. OBJECTIVE: Lateral lumbar interbody fusion (LLIF) commonly involves a transpsoas approach. Despite the association between LLIF, postoperative iliopsoas weakness, and iatrogenic neuropraxia, no study has yet examined the effect of psoas or multifidus muscle quality on patient-reported outcomes (PROs). METHODS: This study retrospectively reviewed patients who underwent LLIF with 1-year minimum follow-up. Psoas and multifidus muscle qualities were graded on preoperative magnetic resonance imaging using two validated classification systems for muscle atrophy. Average muscle quality was calculated as the mean score from all levels (L1-2 through L5-S1). Univariate and multivariate statistics were utilized to investigate the relationship between psoas/multifidus muscle quality and preoperative, 6-weeks postoperative, and final postoperative PROs. RESULTS: 74 patients (110 levels) with a mean follow-up of 18.71 ± 8.02 months were included for analysis. Greater multifidus atrophy was associated with less improvement on ODI, SF12, and VR12 (P < .05) on univariate analysis. On multivariate analysis, worse multifidus atrophy predicted less improvement on SF12 and VR12 (P < .05). CONCLUSION: Despite the direct manipulation of the psoas muscle inherent to LLIF, preoperative psoas muscle quality did not affect postoperative outcomes. Rather, the extent of preoperative multifidus fatty infiltration and atrophy was more likely to predict postoperative pain and disability. These findings suggest that multifidus atrophy may be more pertinent than psoas atrophy in its association with patient-reported outcome measures after LLIF.

Impact of Lower Extremity Arthroplasty on Improvement of Quality-of-Life Outcomes Following Lumbar Fusion.

BACKGROUND: Both hip-spine and knee-spine syndromes can significantly impact a patient's quality of life; however, few studies have investigated their effect on postoperative outcomes following lumbar fusion. OBJECTIVE: Our study aimed to evaluate the impact of a prior lower extremity arthroplasty on the improvement of patient-reported outcome measures (PROMs) following lumbar fusion surgery. METHODS: Patients undergoing primary, single, or multilevel lumbar interbody fusion were retrospectively reviewed. Patients missing preoperative PROMs were excluded. PROMs were collected preoperatively and postoperatively and included the Oswestry Disability Index (ODI), 12-Item Short Form Physical Component Summary, Patient-Reported Outcomes Measurement Information System Physical Function, and visual analog scale (VAS). A minimum clinically important difference (MCID) was calculated. Patients were categorized based on a history of hip/knee arthroplasty and propensity score matched. Intragroup improvement of PROM scores and intergroup differences in mean scores were evaluated using a paired t test and linear regression. MCID achievement differences were evaluated using logistic regression. RESULTS: A total of 335 patients were included, with 25 having a history of hip/knee arthroplasty. Arthroplasty patients were significantly older (P = 0.001) and typically had a higher Charlson Comorbidity Index (P ≤ 0.003, both). Patients differed in spinal pathology of degenerative spondylolisthesis (P = 0.049). Nonarthroplasty patients demonstrated significant improvements in all PROMs by 2 years (P < 0.001, all). The arthroplasty group demonstrated significant improvements in all PROMs by 1 year (P < 0.031, all). Preoperative VAS back was significantly worse for nonarthroplasty patients (P = 0.035). MCID achievement did not significantly differ between groups except at 6 months for ODI (P = 0.035). CONCLUSION: Following lumbar fusion, patients with a past surgical history did not demonstrate differences in outcome measures or MCID from those without. These results suggest that comorbid orthopedic conditions requiring surgery do not negatively impact the ability of patients to improve following lumbar fusion. CLINICAL RELEVANCE: Prior surgical history of lower extremity arthroplasty should not discourage the use of lumbar fusion when properly indicated, as patients reported clinical improvement regardless of history of hip or knee arthroplasty.

Segmental range of motion after cervical total disc arthroplasty at long-term follow-up: a systematic review and meta-analysis.

OBJECTIVE: As an alternative procedure to anterior cervical discectomy and fusion, total disc arthroplasty (TDA) facilitates direct neural decompression and disc height restoration while also preserving cervical spine kinematics. To date, few studies have reported long-term functional outcomes after TDA. This paper reports the results of a systematic review and meta-analysis that investigated how segmental range of motion (ROM) at the operative level is maintained with long-term follow-up. METHODS: PubMed and MEDLINE were queried for all published studies pertaining to cervical TDA. The methodology for screening adhered strictly to the PRISMA guidelines. All English-language prospective studies that reported ROM preoperatively, 1 year postoperatively, and/or at long-term follow-up of 5 years or more were included. A meta-analysis was performed using Cochran's Q and I2 to test data for statistical heterogeneity, in which case a random-effects model was used. The mean differences (MDs) and associated 95% confidence intervals (CIs) were reported. RESULTS: Of the 12 studies that met the inclusion criteria, 8 reported the long-term outcomes of 944 patients with an average (range) follow-up of 99.86 (60-142) months and were included in the meta-analysis. There was no difference between preoperative segmental ROM and segmental ROM at 1-year follow-up (MD 0.91°, 95% CI -1.25° to 3.07°, p = 0.410). After the exclusion of 1 study from the comparison between preoperative and 1-year ROM owing to significant statistical heterogeneity according to the sensitivity analysis, ROM significantly improved at 1 year postoperatively (MD 1.92°, 95% CI 1.04°-2.79°, p < 0.001). However, at longer-term follow-up, the authors again found no difference with preoperative segmental ROM, and no study was excluded on the basis of the results of further sensitivity analysis (MD -0.22°, 95% CI -1.69° to -1.23°, p = 0.760). In contrast, there was a significant decrease in ROM from 1 year postoperatively to final long-term follow-up (MD -0.77°, 95% CI -1.29° to -0.24°, p = 0.004). CONCLUSIONS: Segmental ROM was found to initially improve beyond preoperative values for as long as 1 year postoperatively, but then ROM deteriorated back to values consistent with preoperative motion at long-term follow-up. Although additional studies with further longitudinal follow-up are needed, these findings further support the notion that cervical TDA may successfully maintain physiological spinal kinematics over the long term.

Changes in peri-apical vertebral body and intervertebral disc shape in both the sagittal and coronal planes correlate with scoliosis severity: a 3D study of 397 patients.

PURPOSE: To evaluate associations between vertebrae and disc shape asymmetry and adolescent idiopathic scoliosis (AIS) curve severity. METHODS: Analysis included normal screening referrals and patients with right, main thoracic AIS who underwent upright, biplanar radiographs with 3D reconstruction at a single institution from 2010 to 2015. Peri-apical anterior, posterior, right, and left vertebral body heights (aVBH, pVBH, rVBH, lVBH) and intervertebral disc heights (DH) were measured, and ratios of these measurements were calculated in sagittal and coronal planes. Correlations were performed between curve severity and height measurements. Sagittal and coronal plane components of these measurements were compared between normal controls with coronal curve measurements < 11° and patients with moderate (11°-49°) and severe curves (≥ 50°), with tolerance intervals established for the normal controls. RESULTS: The analysis included a total of 397 patients. Patients with AIS had coronal curve measurements ranging from 11° to 101°. Greater coronal curve severity strongly correlated with smaller pVBH relative to aVBH and moderately correlated with smaller pDH relative to aDH (r = - 0.643, r = - 0.305, respectively). aVBH was greater for larger curves; pVBH remained stable. Scoliosis severity strongly correlated with right relative to left VBH and DH ratios (r = 0.919, r = 0.865 respectively). In comparison of normal controls to severe curves, severe curves had significantly greater aVBH and aDH, while pVBH was not significantly different and pDH was significantly less. Nearly half (46.9%) of the severe curves were below the range of normal for PA vertebral height ratio. CONCLUSION: In right, main thoracic AIS, greater main thoracic curve severity is associated with greater sagittal and coronal plane asymmetry of both the vertebral bodies and the discs. Severity more strongly correlates with vertebral changes in symmetry than with disc changes, though both are present.

Predictors of spontaneous lumbar curve correction in thoracic-only fusions: 3D analysis in AIS.

PURPOSE: To evaluate how 3D parameters of the instrumented thoracic spine relate to the uninstrumented lumbar spine following thoracic-only fusion (TOF) for adolescent idiopathic scoliosis (AIS) and determine the factors predictive of lumbar correction. METHODS: A multi-center retrospective review was conducted of AIS patients with Lenke 1-4 B or C curves undergoing fusion of their thoracic spine only with minimum 2-year follow-up and 3D spine reconstructions from biplanar radiography. Pre-operative to 2-year post-operative differences were evaluated. Pearson's correlations were used to identify 3D coronal, sagittal and axial relationships at 2 years post-operative. Multivariate linear regression was used to identify variables most predictive of lumbar curve correction. RESULTS: Eighty-four AIS patients met inclusion (54 B modifiers, 30 C modifiers). Average pre-operative thoracic and lumbar curves were 54 ± 9° and 41 ± 7° and corrected to 19 ± 7° and 21 ± 7°, respectively. 3D T5-T12 thoracic kyphosis increased from 6 ± 13° to 26 ± 8°. Thoracic and lumbar apical rotation decreased from - 14 ± 6° to -5 ± 6° and 13 ± 5° to 11 ± 6°, respectively. Thoracic curve correction correlated with lumbar curve correction (r = 0.67, p = 0.001) and decreased LIV tilt correlated with smaller residual lumbar curve magnitude (r = 0.63, p < 0.001). Increasing 3D kyphosis of the instrumented segment correlated with increased percentage lumbar curve correction (r = 0.29, p = 0.009). Multivariate linear regression showed LIV tilt and thoracic curve magnitude as the most predictive variables of post-operative residual lumbar curve magnitude, and percent correction of the thoracic curve and change in 3D instrumented kyphosis as most predictive of percent correction of the lumbar curve. CONCLUSIONS: Analysis of 3D data highlights several considerations for AIS patients undergoing TOF. Maximizing thoracic curve correction, leveling the LIV, and to a lesser extent, restoring kyphosis in the instrumented segment are the factors most likely to result in greater correction of the instrumented lumbar curve following thoracic-only fusions in Lenke 1-4 B and C curves.

Identifying the axillary nerve during shoulder surgery: an anatomic study using advanced imaging.

BACKGROUND: The axillary nerve (AXN) is one of the more commonly injured nerves during shoulder surgery. Prior anatomic studies of the AXN in adults were performed using cadaveric specimens with small sample sizes. Our research observes a larger cohort of magnetic resonance imaging (MRI) studies in order to gain a more representative sample of the course of the AXN and aid surgeons intraoperatively. METHODS: High-resolution 3T MRI studies performed at our institution from January 2010 to June 2019 were reviewed. Four blinded reviewers with musculoskeletal radiology or orthopedic surgery training measured the distance of the AXN to the surgical neck of the humerus (SNH), the lateral tip of the acromion (LTA), and the inferior glenoid rim (IGR). Intraclass correlation coefficient was calculated to assess reliability between reviewers. The nerve location was assessed relative to rotator cuff tear status. RESULTS: A total of 257 shoulder MRIs were included. Intraclass correlation coefficient was excellent at 0.80 for the SNH, 0.90 for the LTA, and 0.94 for the IGR. All intraobserver reliabilities were above 0.80. The mean distance from the AXN to SNH was 1.7 cm (range, 0.7-3.1 cm; interquartile range, 1.38-2.00) and that from the AXN to IGR was 1.6 cm (range, 0.6-2.6 cm; interquartile range, 1.33-1.88). The mean AXN to LTA distance was 7.1 cm, with a range of 5.2-9.0 cm across patient heights; there was a large effect size related to the LTA to AXN distance and patient height with a correlation of r = 0.603 (P < .001). Rotator cuff pathology appears to affect nerve location by increasing the distance between the AXN and SNH (P = .027). DISCUSSION/CONCLUSION: The AXN is vulnerable to injury during both open and arthroscopic shoulder procedures. This injury can be either a result of direct trauma to the nerve or secondary to traction placed on the nerve with reconstructive procedures that distalize the humerus. Our study demonstrates that the AXN can be found as little as 5.6 mm from the IGR and 6.9 mm from the SNH. In addition, we illustrate the relationship between patient height and the LTA to AXN distance and complete rotator cuff tears and the SNH to AXN distance. Our study is the first to demonstrate the nerve's proximity to important surgical landmarks of the shoulder using a large sample size of high-resolution images in living human shoulders.

Relationship Between Lumbar Lordosis and Pelvic Incidence in the Adolescent Patient: Normal Cohort Analysis and Literature Comparison.

STUDY DESIGN: Retrospective review; literature comparison. OBJECTIVES: To review the literature on the relationship between lumbar lordosis (LL) and pelvic incidence (PI) and evaluate this relationship in asymptomatic adolescents while testing the validity of previously reported adult correlation models between LL and PI in an adolescent population. SUMMARY OF BACKGROUND DATA: Accurate understanding of the normal spinopelvic relationship is critical when considering surgical fusion of the lumbar spine. Many studies have reported relationships between pelvic measurements and LL in adult populations, but data in pediatric populations is lacking. METHODS: A literature search was performed to identify previously reported relationships between pelvic parameters and LL in adults and pediatric patients. A cohort of 125 asymptomatic adolescent patients evaluated at our institution was evenly split into two cohorts for model development and validation. Linear regression between LL and PI was performed. The resultant regression model was tested in the validation cohort along with previously reported formulae with LL as a function of PI. Mean absolute error (MAE) was calculated and compared between prior models and the newly developed adolescent model using analysis of variance and post-hoc testing. RESULTS: In our adolescent cohort (mean age: 13 ± 2), there was a strong correlation between PI and LL (r = 0.53). Regression analysis in the development cohort produced the following predictive model: LL = 0.66(PI) + 24.2. Testing in the validation cohort revealed a good correlation between predicted and actual LL (r = 0.51) and an MAE of 8.3. All but three previously reported models functioned with similar accuracy in the adolescent population, with only two methods having an MAE over 10. CONCLUSIONS: The majority of previously published formulae for predicting LL as a function of PI developed in adults can be extrapolated to adolescent populations. These relationships are important in understanding how to surgically restore the sagittal alignment in adolescents with spinal deformity. LEVEL OF EVIDENCE: Level IV.

A Novel Method for Estimating Three-Dimensional Apical Vertebral Rotation Using Two-Dimensional Coronal Cobb Angle and Thoracic Kyphosis.

STUDY DESIGN: Retrospective cohort analysis. OBJECTIVES: To use a large cohort of three-dimensional (3D) spinal reconstructions to create a simple mathematical formula capable of estimating 3D apical vertebral rotation (AVR) based on the correlation with routinely obtained two-dimensional (2D) measurements of scoliosis. SUMMARY OF BACKGROUND DATA: Quantification of vertebral rotation in AIS using 2-dimensional (2D) imaging is inherently challenging as the axial plane cannot be directly visualized. METHODS: A database of 279 3D spinal reconstructions was queried for patients with thoracic major adolescent idiopathic scoliosis (AIS). 2D thoracic Cobb angle, T5-T12 thoracic kyphosis, pelvic incidence, sacral slope, and pelvic tilt were recorded. 3D AVR was calculated for each patient from 3D reconstructions. Patients were divided into development (n = 186) and validation (n = 93) cohorts. Within the development cohort, univariate analysis was performed between 2D measurements and 3D AVR with significance set at p < .05 for inclusion in multivariate analysis. In multivariate analysis, significance was set at p < .01 for inclusion in the final model. Model performance was tested in development and validation cohorts. RESULTS: Only 2D thoracic Cobb and T5-T12 thoracic kyphosis had significance in univariate (p < .05) and multivariate analyses (p < .01), meriting inclusion in the final model. 3D AVR (°) = 0.26*(T5-T12 kyphosis) + 0.34*(coronal Cobb) - 5.38. In the development cohort, the model performed well (R = 0.739, r2 = 0.54). In testing with the validation cohort, the model proved generalizability (R = 0.703) and had a mean absolute error <5°. CONCLUSIONS: This model is capable of estimating 3D AVR given 2D thoracic Cobb and T5-T12 kyphosis. The accuracy of this method is comparable to previously reported methods of 2D axial rotation measurement. However, this model provides 3D axial rotation and requires no physical instruments, non-standard measurements, or software programs. Such a model is valuable for both routine evaluation of AIS and operative preparation. LEVEL OF EVIDENCE: Level II, diagnostic.

Thoracic Idiopathic Scoliosis Severity Is Highly Correlated with 3D Measures of Thoracic Kyphosis.

BACKGROUND: Loss of thoracic kyphosis has been associated with thoracic idiopathic scoliosis. Modern 3-dimensional (3D) imaging systems allow more accurate characterization of the scoliotic deformity than traditional radiographs. In this study, we utilized 3D calculations to characterize the association between increasing scoliosis severity and changes in the sagittal and axial planes. METHODS: Patients evaluated in a scoliosis clinic and determined to have either a normal spine or idiopathic scoliosis were included in the analysis. All underwent upright, biplanar radiography with 3D reconstructions. Two-dimensional (2D) measurements of the magnitude of the thoracic major curve and the thoracic kyphosis were recorded. Image processing and MATLAB analysis were utilized to produce a 3D calculation of thoracic kyphosis and apical vertebral axial rotation. Regression analysis was performed to determine the correlation of 2D kyphosis, 3D kyphosis, and apical axial rotation with the magnitude of the thoracic major curve. RESULTS: The 442 patients for whom 2D and 3D data were collected had a main thoracic curve magnitude ranging from 1° to 118°. Linear regression analysis of the 2D and 3D T5-T12 kyphosis versus main thoracic curve magnitude yielded significant models (p < 0.05). The 2D model had a minimally negative slope (-0.07), a small R value (0.02), and a poor correlation coefficient (-0.14). In contrast, the 3D model had a strongly negative slope (-0.54), a high R value (0.56), and a strong correlation coefficient (-0.75). Curve magnitude also had a strong correlation with loss of 3D T1-T12 kyphosis and increasing apical axial rotation. CONCLUSIONS: Segmentally calculated 3D thoracic kyphosis had a strongly negative correlation with the magnitude of the main thoracic curve. With near uniformity, 3D thoracic kyphosis progressively decreased as scoliosis magnitude increased, at a rate of more than half the increase in the main thoracic curve magnitude. Analysis confirmed a surprisingly strong correlation between scoliosis severity and loss of 3D kyphosis that was absent in the 2D analysis. A similarly strong correlation between curve magnitude and apical axial rotation was evident. These findings lend further credence to the concept that scoliosis progresses in the coronal, sagittal, and axial planes simultaneously. CLINICAL RELEVANCE: The findings of this study suggest that 3D assessment is critical for adequate characterization of the multiplanar deformity of idiopathic scoliosis and deformity in the sagittal plane is linked to deformity in the coronal plane. Increasing severity of coronal plane curvature is associated with a progressive loss of thoracic kyphosis that should be anticipated so that the appropriate intraoperative techniques for correction of idiopathic scoliosis can be applied in all 3 planes.

Analysis of Internet information on the controversial X-Stop device.

BACKGROUND CONTEXT: The Internet is frequently used by patients to aid in medical decision making. Multiple studies display the Internet's ineffectiveness in presenting high-quality information regarding surgical procedures and devices. With recent reports of unacceptably high complication rates and poor outcomes with the X-Stop device, it is important that online information is comprehensive and accurate. This study is the first to examine Internet information on the controversial X-Stop. PURPOSE: To determine how accurately public information over the Internet portrays the existing primary literature on the X-Stop, how extensively the X-Stop is characterized online, and how patient decision making could foreseeably be affected. STUDY DESIGN: This cross-sectional study analyzed publicly available Internet information, including videos on the web site YouTube regarding the X-Stop device. PATIENT SAMPLE: No patients were involved in this study. OUTCOME MEASURES: No specific outcome measures were used. METHODS: Search engines Google, Yahoo, and Bing were used to identify 105 web sites providing information on the X-Stop. Videos on the web site YouTube were included. Web sites were categorized based on the authorship. Each site was analyzed for the provision of appropriate patient inclusion and exclusion criteria, surgical and nonsurgical treatment alternatives, purported benefits, common complications, peer-reviewed literature citations, and descriptions/diagrams of the procedure. Data were evaluated for each authorship subgroup and the entire group of sites. RESULTS: Forty-three percent of sites were authored by a private medical group, 4% by an academic medical group, 16% by an insurance company, 9% by a biomedical industry, 10% by news sources, and 19% by other. Thirty-one percent of web sites and 11% of sites authored by private medical groups contained references to peer-reviewed literature. Fifty-six percent of web sites reported patient inclusion criteria, whereas 33% reported exclusion criteria. Benefits and complications were reported within 91% and 23% of sites, respectively. Surgical and nonsurgical treatment options were mentioned within 59% and 61% of web sites, respectively. CONCLUSIONS: Our study demonstrates the Internet's ineffectiveness in reporting quality information on the X-Stop. Information was often incomplete and potentially misleading. Significant controversy exists within primary literature regarding the safety and efficacy of the X-Stop. Yet, publicly available Internet information largely provided misinformation and did not reflect any such controversy. This raises the concern that such information lends itself more toward patient recruitment than patient education. Medical professionals need to know how this may affect their patients' decision making.

Use of high-field intraoperative magnetic resonance imaging to enhance the extent of resection of enhancing and nonenhancing gliomas.

BACKGROUND: Intraoperative magnetic resonance imaging (IoMRI) is used to improve the extent of resection of brain tumors. Most previous studies evaluating the utility of IoMRI have focused on enhancing tumors. OBJECTIVE: To report our experience with the use of high-field IoMRI (1.5 T) for both enhancing and nonenhancing gliomas. METHODS: An institutional review board-approved retrospective review was performed of 102 consecutive glioma patients (104 surgeries, 2010-2012). Pre-, intra-, and postoperative tumor volumes were assessed. Analysis was performed with the use of volumetric T2 images in 43 nonenhancing and 13 minimally enhancing tumors and with postcontrast volumetric magnetization-prepared rapid gradient-echo images in 48 enhancing tumors. RESULTS: In 58 cases, preoperative imaging showed tumors likely to be amenable to complete resection. Intraoperative electrocorticography was performed in 32 surgeries, and 14 cases resulted in intended subtotal resection of tumors due to involvement of deep functional structures. No further resection (complete resection before IoMRI) was required in 25 surgeries, and IoMRI showed residual tumor in 79 patients. Of these, 25 surgeries did not proceed to further resection (9 due to electrocorticography findings, 14 due to tumor in deep functional areas, and 2 due to surgeon choice). Additional resection that was performed in 54 patients resulted in a final median residual tumor volume of 0.21 mL (0.6%). In 79 patients amenable to complete resection, the intraoperative median residual tumor volume for the T2 group was higher than for the magnetization-prepared rapid gradient-echo group (1.088 mL vs 0.437 mL; P = .049), whereas the postoperative median residual tumor volume was not statistically significantly different between groups. CONCLUSION: IoMRI enhances the extent of resection, particularly for nonenhancing gliomas.