Robert A Hart

University of Kansas, Lawrence, Kansas, United States

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Publications (111)243.12 Total impact

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    ABSTRACT: Study Design Multicenter, prospective, consecutive, surgical case series from the International Spine Study Group. Objectives To evaluate the effectiveness of surgical treatment in restoring spinopelvic (SP) alignment. Summary of Background Data Pain and disability in the setting of adult spinal deformity have been correlated with global coronal alignment (GCA), sagittal vertical axis (SVA), pelvic incidence/lumbar lordosis mismatch (PI-LL), and pelvic tilt (PT). One of the main goals of surgery for adult spinal deformity is to correct these parameters to restore harmonious SP alignment. Methods Inclusion criteria were operative patients (age greater than 18 years) with baseline (BL) and 1-year full-length X-rays. Thoracic and thoracolumbar Cobb angle and previous mentioned parameters were calculated. Each parameter at BL and 1 year was categorized as either pathological or normal. Pathologic limits were: Cobb greater than 30°, GCA greater than 40 mm, SVA greater than 40 mm, PI-LL greater than 10°, and PT greater than 20°. According to thresholds, corrected or worsened alignment groups of patients were identified and overall radiographic effectiveness of procedure was evaluated by combining the results from the coronal and sagittal planes. Results A total of 161 patients (age, 55 ± 15 years) were included. At BL, 80% of patients had a Cobb angle greater than 30°, 25% had a GCA greater than 40 mm, and 42% to 58% had a pathological sagittal parameter of PI-LL, SVA, and/or PT. Sagittal deformity was corrected in about 50% of cases for patients with pathological SVA or PI-LL, whereas PT was most commonly worsened (24%) and least often corrected (24%). Only 23% of patients experienced complete radiographic correction of the deformity. Conclusions The frequency of inadequate SP correction was high. Pelvic tilt was the parameter least likely to be well corrected. The high rate of SP alignment failure emphasizes the need for better preoperative planning and intraoperative imaging.
    Spine Deformity. 05/2014; 2(3):219–225.
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    ABSTRACT: Object Increased sagittal vertical axis (SVA) correlates strongly with pain and disability for adults with spinal deformity. A subset of patients with sagittal spinopelvic malalignment (SSM) have flatback deformity (pelvic incidence-lumbar lordosis [PI-LL] mismatch > 10°) but remain sagittally compensated with normal SVA. Few data exist for SSM patients with flatback deformity and normal SVA. The authors' objective was to compare baseline disability and treatment outcomes for patients with compensated (SVA < 5 cm and PI-LL mismatch > 10°) and decompensated (SVA > 5 cm) SSM. Methods The study was a multicenter, prospective analysis of adults with spinal deformity who consecutively underwent surgical treatment for SSM. Inclusion criteria included age older than 18 years, presence of adult spinal deformity with SSM, plan for surgical treatment, and minimum 1-year follow-up data. Patients with SSM were divided into 2 groups: those with compensated SSM (SVA < 5 cm and PI-LL mismatch > 10°) and those with decompensated SSM (SVA ≥ 5 cm). Baseline and 1-year follow-up radiographic and health-related quality of life (HRQOL) outcomes included Oswestry Disability Index, Short Form-36 scores, and Scoliosis Research Society-22 scores. Percentages of patients achieving minimal clinically important difference (MCID) were also assessed. Results A total of 125 patients (27 compensated and 98 decompensated) met inclusion criteria. Compared with patients in the compensated group, patients in the decompensated group were older (62.9 vs 55.1 years; p = 0.004) and had less scoliosis (43° vs 54°; p = 0.002), greater SVA (12.0 cm vs 1.7 cm; p < 0.001), greater PI-LL mismatch (26° vs 20°; p = 0.013), and poorer HRQOL scores (Oswestry Disability Index, Short Form-36 physical component score, Scoliosis Research Society-22 total; p ≤ 0.016). Although these baseline HRQOL differences between the groups reached statistical significance, only the mean difference in Short Form-36 physical component score reached threshold for MCID. Compared with baseline assessment, at 1 year after surgery improvement was noted for patients in both groups for mean SVA (compensated -1.1 cm, decompensated +4.8 cm; p ≤ 0.009), mean PI-LL mismatch (compensated 6°, decompensated 5°; p < 0.001), and all HRQOL measures assessed (p ≤ 0.005). No significant differences were found between the compensated and decompensated groups in the magnitude of HRQOL score improvement or in the percentages of patients achieving MCID for each of the outcome measures assessed. Conclusions Decompensated SSM patients with elevated SVA experience significant disability; however, the amount of disability in compensated SSM patients with flatback deformity caused by PI-LL mismatch but normal SVA is underappreciated. Surgical correction of SSM demonstrated similar radiographic and HRQOL score improvements for patients in both groups. Evaluation of SSM should extend beyond measuring SVA. Among patients with concordant pain and disability, PI-LL mismatch must be evaluated for SSM patients and can be considered a primary indication for surgery.
    Journal of neurosurgery. Spine 04/2014; · 1.61 Impact Factor
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    ABSTRACT: Study Design. Multicenter, retrospective review.Objective. Assess rates, site variability, and risk factors for revision surgery (RS) following three-column osteotomy(3CO).Summary of Background Data. Complex spinal osteotomies, including 3CO, are being increasingly performed in the setting of adult spinal deformity (ASD) patients with sagittal plane deformity. 3CO procedures are associated with high complication and RS rates, but risk factors for complications and variability across centers for revision have not been well defined.Methods. The incidence and indications for RS in 335 ASD patients were analyzed. RS indications were classified as "mechanical"(MR: implant failure, pseudarthrosis, junctional failure, loss/lack of correction) or "non-mechanical"(NMR: neurologic deficit, infection, wound dehiscence, stenosis). Risks factors for RS were analyzed using generalized linear models.Results. Three-month and one-year RS incidences were 12.3% and 17.6%, respectively. Single-level 3CO (n = 311) had lower RS rates than multi-level 3CO(n = 24, 15.8% vs. 41.7%, p = 0.001). The 16.7% rate for single-level lumbar 3CO included 11.4% for MR and 5.7% for NMR. For all RS, 50% of MR and 78.6% of NMR occurred within three-months of the index surgery. There was significant variation in rates across sites(range = 6.3% to 31.9%, p = 0.001), however low- and high-volume sites had similar rates(18.2% vs. 16.2%, p = 0.503). Patients with MR were more likely to be sagittaly under-corrected at three-months(SVA = 7cm vs 3.2cm, p = 0.003). Patients with NMR had more caudal 3CO levels (L4 vs L3, p = 0.014) and larger 3CO bone resections than patients who did not(34° vs 24.5°, p = 0.003).Conclusions. 3CO procedures for ASD surgery can provide significant deformity correction and lead to marked improvement in function despite established complication and revision rates. This study shows that RS is associated with lower level osteotomy and higher residual SVA. There is significant variability in revision rates across sites independent of site volume, suggesting potential systems and practice variations that warrant further study.
    Spine 02/2014; · 2.45 Impact Factor
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    ABSTRACT: Object The ideal surgical management of high-grade spondylolisthesis remains unclear. Concerns regarding the original Bohlman transsacral interbody fusion technique with stand-alone autologous fibular strut include late graft fracture and incomplete reduction of lumbosacral kyphosis. The authors' goal was to evaluate the radiographic and surgical outcomes of patients treated for high-grade spondylolisthesis with either transsacral S-1 screws or standard pedicle screw fixation augmenting the Bohlman posterior transsacral interbody fusion technique. Methods A retrospective review of patients who underwent fusion for high-grade spondylolisthesis in which a Bohlman oblique posterior interbody fusion augmented with either transsacral or standard pedicle screw fixation was performed by 4 spine surgeons was completed. Estimated blood loss, operating time, perioperative complications, and need for revision surgery were evaluated. Upright pre- and postsurgical lumbar spine radiographs were compared for slip percent and slip angle. Results Sixteen patients (12 female and 4 male) with an average age of 29 years (range 9-66 years) were evaluated. The average clinical follow-up was 78 months (range 5-137 months) and the average radiographic follow-up was 48 months (range 5-108 months). Ten L4-S1 and 6 L5-S1 fusions were performed. Five fibular struts and 11 titanium mesh cages were used for interbody fusion. Six patients had isolated transsacral screws placed, with 2 (33%) of the 6 requiring revision surgery for nonunion. No nonunions were observed in patients undergoing spanning pedicle screw fixation augmenting the interbody graft. Six patients experienced perioperative complications including 3 iliac crest site infections, 1 L-5 radiculopathy without motor involvement, 1 deep vein thrombosis, and 1 epidural hematoma requiring irrigation and debridement. The average estimated blood loss and operating times were 763 ml and 360 minutes, respectively. Slip percent improved from an average of 62% to 37% (n = 16; p < 0.01) and slip angle improved from an average of 18° to 8° (n = 16; p < 0.01). No patient experienced L-5 or other motor deficit postoperatively. Conclusions The modified Bohlman technique for treatment of high-grade spondylolisthesis has reproducible outcomes among multiple surgeons and results in significant improvements in slip percent and slip angle. Fusion rates were high (14 of 16; 88%), especially with spanning instrumentation augmenting the oblique interbody fusion. Rates of L-5 motor deficit were low in comparison with techniques involving reduction of the anterolisthesis.
    Journal of neurosurgery. Spine 02/2014; · 1.61 Impact Factor
  • Paul A Anderson, Robert A Hart
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    ABSTRACT: Adverse events reporting in pivotal trials of new technologies, such as cervical total disk replacement, are essential to determine safety. Important questions concerning the adequacy of reporting about such new technologies in peer-reviewed publications have prompted this analysis to assess the safety of cervical disk replacement compared with fusion as presented in peer-reviewed publications and FDA summary reports. Identifying differences among these reports highlight the poor quality of adverse event reporting in the peer-reviewed literature. Nine peer-reviewed studies and five FDA summary reports documented excellent safety for both cervical fusion and disk arthroplasty. No differences in rates of adverse events were found to exist between the two treatments. The methods of recording and the actual reporting of adverse events were poor in peer-reviewed manuscripts, whereas they were comprehensive but difficult to clinically apply in the FDA summaries. Recommendations to improve documentation and reporting of adverse events are presented.
    Instructional course lectures 01/2014; 63:287-96.
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    ABSTRACT: Safety information in spine surgery is important for informed patient choice and performance-based payment incentives, but measurement methods for surgical safety assessment are not standardized. Published reports of complication rates for common spinal procedures show wide variation. Factors influencing variation may include differences in safety ascertainment methods and procedure types. In a prospective cohort study, adverse events were observed in all patients undergoing spine surgery at two hospitals during a 2-year period. Multiple processes for adverse occurrence surveillance were implemented, and the associations between surveillance methods, surgery invasiveness, and observed frequencies of adverse events were examined. The study enrolled 1,723 patients. Adverse events were noted in 48.3% of the patients. Reviewers classified 25% as minor events and 23% as major events. Of the major events, the daily rounding team reported 38.4% of the events using a voluntary reporting system, surgeons reported 13.4%, and 9.1% were identified during clinical conferences. A review of medical records identified 86.7% of the major adverse events. The adverse events occurred during the inpatient hospitalization for 78.1% of the events, within 30 days for an additional 12.5%, and within the first year for the remaining 9.4%. A unit increase in the invasiveness index was associated with an 8.2% increased risk of a major adverse event. A Current Procedural Terminology-based algorithm for quantifying invasiveness correlated well with medical records-based assessment. Increased procedure invasiveness is associated with an increased risk of adverse events. The observed frequency of adverse events is influenced by the ascertainment modality. Voluntary reports by surgeons and other team members missed more than 50% of the events identified through a medical records review. Increased surgery invasiveness, measured from medical records or billing codes, is quantitatively associated with an increased risk of adverse events.
    Instructional course lectures 01/2014; 63:271-86.
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    ABSTRACT: Few studies have examined threshold improvements in health-related quality of life (HRQOL) by measuring minimal clinically important differences (MCIDs) in treatment of adult spinal deformity. We hypothesized that patients undergoing operative treatment would be more likely to achieve MCID threshold improvement compared with those receiving nonoperative care, although a subset of nonoperative patients may still reach threshold. We analyzed a multicenter, prospective, consecutive case series of 464 patients: 225 nonoperative and 239 operative. To be included in the study, patients had to have adult spinal deformity, be older than 18 years, and have both baseline and 1-year follow-up HRQOL measures (Oswestry Disability Index [ODI], Short Form-36 [SF-36] health survey, and Scoliosis Research Society-22 [SRS-22] questionnaire). We compared the percentages of patients achieving established MCID thresholds between operative and nonoperative groups using risk ratios (RR) with a 95% confidence interval (CI). Compared to nonoperative patients, surgical patients demonstrated significant mean improvement (P<0.01) and were more likely to achieve threshold MCID improvement across all HRQOL scores (ODI RR = 7.37 [CI 4.45, 12.21], SF-36 physical component score RR = 2.96 [CI 2.11, 4.15], SRS Activity RR = 3.16 [CI 2.32, 4.31]). Furthermore, operative patients were more likely to reach threshold MCID improvement in 2 or more HRQOL measures simultaneously and were less likely to deteriorate. Patients in both the operative and nonoperative treatment groups demonstrated improvement in at least one HRQOL measure at 1 year. However, surgical treatment was more likely to result in threshold improvement and more likely to lead to simultaneous improvement across multiple measures of ODI, SF-36, and SRS-22. Although a subset of nonoperative patients achieved threshold improvement, nonoperative patients were significantly less likely to improve in multiple HRQOL measures and more likely to sustain MCID deterioration or no change.
    Ochsner Journal 01/2014; 14(1):67-77.
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    ABSTRACT: Study Design. Multi-center, prospective analysis of consecutive ASD patients.Objective. Evaluate complications associated with rhBMP-2 use in ASDSummary of Background Data. Off-label rhBMP-2 use is common, however under-reporting of rhBMP-2 associated complications has been recently scrutinized.Methods. ASD patients consecutively enrolled into a prospective, multicenter database, were evaluated for type and timing of acute perioperative complications. Inclusion criteria: age ≥ 18 years, ASD, spinal arthrodesis >4 levels, and ≥3 months follow-up. Patients divided into those receiving rhBMP-2 (BMP) or no rhBMP-2 (NOBMP). BMP divided into location of use: posterior (PBMP), interbody (IBMP), and interbody + posterior spine (I+PBMP). Correlations between acute perioperative complications and rhBMP-2 use including total dose, dose/level and location of use were evaluated.Results. 279 patients (mean age 57 years, mean spinal levels fused 12.0, mean follow-up 28.8 months) met inclusion criteria. BMP (n = 172; average posterior dose = 2.5 mg/level, average interbody dose = 5 mg/level) had similar age, smoking history, previous spine surgery, total spinal levels fused, estimated blood loss, and duration of hospital stay as NOBMP (n = 107; p>0.05). BMP had greater Charlson Comorbidity Index (1.9 vs. 1.2), greater scoliosis (43° vs. 38°), longer operative time (488.2 vs. 414.6 minutes), more osteotomies/patient (4.0 vs. 1.6) and greater percentage of anteroposterior fusion (APSF; 20.9% vs. 8.4%) than NOBMP, respectively (p<0.05). BMP had more total complications/patient (1.4 vs.0.6) and more minor complications/patient (0.9 vs. 0.2) than NOBMP, respectively (p<0.05). NOBMP had more complications requiring surgery/patient than BMP (0.3 vs. 0.2; p<0.05). Major, neurological, wound, and infection complications were similar for NOBMP, BMP, PBMP, IBMP, and I+PBMP (p>0.05). Multivariate analysis demonstrated small to non-existent correlations between rhBMP-2 use and complications.Conclusions. RhBMP-2 use and location of rhBMP-2 use in ASD surgery, at reported doses, does not increase acute major, neurological or wound complications. Research is needed for higher rhBMP-2 dosing and long-term follow-up.
    Spine 11/2013; · 2.45 Impact Factor
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    ABSTRACT: Controversy persists regarding Recombinant Human Bone Morphogenetic Protein-2 (rhBMP-2) use in spine surgery. We compared minimum 2 year complications, fusion rates and clinical outcomes for BMP and NOBMP patients in a prospective, multicenter consecutive cohort.
    Congress of Neurological Surgeons, San Francisco; 10/2013
  • The Spine Journal 09/2013; 13(9):S8-S9. · 2.80 Impact Factor
  • The Spine Journal 09/2013; 13(9):S116. · 2.80 Impact Factor
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    ABSTRACT: Object Complications and reoperation for surgery to correct adult spinal deformity are not infrequent, and many studies have analyzed the rates and factors that influence the likelihood of reoperation. However, there is a need for more comprehensive analyses of reoperation in adult spinal deformity surgery from a global standpoint, particularly focusing on the 1st year following operation and considering radiographic parameters and the effects of reoperation on health-related quality of life (HRQOL). This study attempts to determine the prevalence of reoperation following surgery for adult spinal deformity, assess the indications for these reoperations, evaluate for a relation between specific radiographic parameters and the need for reoperation, and determine the potential impact of reoperation on HRQOL measures. Methods A retrospective review was conducted of a prospective, multicenter, adult spinal deformity database collected through the International Spine Study Group. Data collected included age, body mass index, sex, date of surgery, information regarding complications, reoperation dates, length of stay, and operation time. The radiographic parameters assessed were total number of levels instrumented, total number of interbody fusions, C-7 sagittal vertical axis, uppermost instrumented vertebra (UIV) location, and presence of 3-column osteotomies. The HRQOL assessment included Oswestry Disability Index (ODI), 36-Item Short Form Health Survey physical component and mental component summary, and SRS-22 scores. Smoking history, Charlson Comorbidity Index scores, and American Society of Anesthesiologists Physical Status classification grades were also collected and assessed for correlation with risk of early reoperation. Various statistical tests were performed for evaluation of specific factors listed above, and the level of significance was set at p < 0.05. Results Fifty-nine (17%) of a total of 352 patients required reoperation. Forty-four (12.5%) of the reoperations occurred within 1 year after the initial surgery, including 17 reoperations (5%) within 30 days. Two hundred sixty-eight patients had a minimum of 1 year of follow-up. Fifty-three (20%) of these patients had a 3-column osteotomy, and 10 (19%) of these 53 required reoperation within 1 year of the initial procedure. However, 3-column osteotomy was not predictive of reoperation within 1 year, p = 0.5476). There were no significant differences between groups with regard to the distribution of UIV, and UIV did not have a significant effect on reoperation rates. Patients needing reoperation within 1 year had worse ODI and SRS-22 scores measured at 1-year follow-up than patients not requiring operation. Conclusions Analysis of data from a large multicenter adult spinal deformity database shows an overall 17% reoperation rate, with a 19% reoperation rate for patients treated with 3-column osteotomy and a 16% reoperation rate for patients not treated with 3-column osteotomy. The most common indications for reoperation included instrumentation complications and radiographic failure. Reoperation significantly affected HRQOL outcomes at 1-year follow-up. The need for reoperation may be minimized by carefully considering spinal alignment, termination of fixation, and type of surgical procedure (presence of osteotomy). Precautions should be taken to avoid malposition or instrumentation (rod) failure.
    Journal of neurosurgery. Spine 08/2013; · 1.61 Impact Factor
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    ABSTRACT: Object Cervical spine osteotomies are powerful techniques to correct rigid cervical spine deformity. Many variations exist, however, and there is no current standardized system with which to describe and classify cervical osteotomies. This complicates the ability to compare outcomes across procedures and studies. The authors' objective was to establish a universal nomenclature for cervical spine osteotomies to provide a common language among spine surgeons. Methods A proposed nomenclature with 7 anatomical grades of increasing extent of bone/soft tissue resection and destabilization was designed. The highest grade of resection is termed the major osteotomy, and an approach modifier is used to denote the surgical approach(es), including anterior (A), posterior (P), anterior-posterior (AP), posterior-anterior (PA), anterior-posterior-anterior (APA), and posterior-anterior-posterior (PAP). For cases in which multiple grades of osteotomies were performed, the highest grade is termed the major osteotomy, and lower-grade osteotomies are termed minor osteotomies. The nomenclature was evaluated by 11 reviewers through 25 different radiographic clinical cases. The review was performed twice, separated by a minimum 1-week interval. Reliability was assessed using Fleiss kappa coefficients. Results The average intrarater reliability was classified as "almost perfect agreement" for the major osteotomy (0.89 [range 0.60-1.00]) and approach modifier (0.99 [0.95-1.00]); it was classified as "moderate agreement" for the minor osteotomy (0.73 [range 0.41-1.00]). The average interrater reliability for the 2 readings was the following: major osteotomy, 0.87 ("almost perfect agreement"); approach modifier, 0.99 ("almost perfect agreement"); and minor osteotomy, 0.55 ("moderate agreement"). Analysis of only major osteotomy plus approach modifier yielded a classification that was "almost perfect" with an average intrarater reliability of 0.90 (0.63-1.00) and an interrater reliability of 0.88 and 0.86 for the two reviews. Conclusions The proposed cervical spine osteotomy nomenclature provides the surgeon with a simple, standard description of the various cervical osteotomies. The reliability analysis demonstrated that this system is consistent and directly applicable. Future work will evaluate the relationship between this system and health-related quality of life metrics.
    Journal of neurosurgery. Spine 07/2013; · 1.61 Impact Factor
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    ABSTRACT: Study Design: Multi-center, retrospective, consecutive case series.Objective: This study aims to identify demographic and radiographic characteristics that influence the decision to perform revision surgery among patients with Proximal Junctional Failure (PJF).Summary of Background Data: Revision rates following PJF remain relatively high, yet the decision criteria for performing revision surgeries is not uniform and varies by surgeon. A better understanding of the factors that impact the decision to perform revision surgery is important in order to improve efficiency of surgical treatment for adult spinal deformity (ASD).Methods: A cohort of 57 PJF patients was identified retrospectively from 1,218 consecutive ASD patients. PJF was identified based on 10° post-operative increase in kyphosis between upper instrumented vertebra (UIV) and UIV+2, along with one or more of the following: fracture of the vertebral body of UIV or UIV +1, posterior osseo-ligamentous disruption, or pull-out of instrumentation at the UIV. Univariate statistical analysis was performed using t-tests and Fisher's exact tests. Multivariate analysis was performed using logistic regression.Results: Twenty-seven (47.4%) patients underwent revision surgery within 6 months of the index operation. Regression results revealed that patients with combined posterior/anterior approaches at index were significantly more likely to undergo revision (p = 0.001) as were patients with more extreme PJK angulation (p = 0.034). Patients sustaining trauma were also significantly more likely to undergo revision (p = 0.019). Variables approaching but not reaching significance as predictors of revision included female gender (p = 0.066) and higher SVA (p = 0.090).Conclusions: The decision to perform revision surgery is complicated and varies by surgeon. Factors that appear to influence this decision include traumatic etiology of PJF, severity of PJK angulation, higher SVA, and female gender. Factors that were expected to influence revision but had no statistical effect included soft-tissue versus bony mode of failure, age, levels fused, and upper thoracic versus thoracolumbar proximal junction.
    Spine 06/2013; · 2.45 Impact Factor
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    ABSTRACT: BACKGROUND:: The Schwab-SRS classification of adult spinal deformity (ASD) is a validated system that provides a common language for the complex pathology of ASD. Classification reliability has been reported; however, correlation with treatment has not been assessed. OBJECTIVE:: To assess the clinical relevance of the SRS-Schwab classification based on correlations with health-related quality of life (HRQOL) measures and the decision to pursue operative versus non-operative treatment. METHODS:: Prospective analysis of consecutive ASD patients (age≥18yrs) collected through a multi-center group. The SRS-Schwab classification includes a curve type descriptor and three sagittal spinopelvic modifiers (sagittal vertical axis, pelvic tilt, pelvic incidence/lumbar lordosis mismatch). Differences in demographics, HRQOL (ODI, SRS-22, SF-36), and classification between operative and non-operative patients were evaluated. RESULTS:: 527 patients (mean age 52.9 years, range: 18.4-85.1) met inclusion criteria. Significant differences in HRQOL were identified based on SRS-Schwab curve type, with thoracolumbar and primary sagittal deformities associated with greater disability and poorer health status than thoracic or double curve deformities. Operative patients had significantly poorer grades for each of the sagittal spinopelvic modifiers, and progressively higher grades were associated with significantly poorer HRQOL (p<0.05). Patients with worse sagittal spinopelvic modifier grades were significantly more likely to require major osteotomies, iliac fixation, and decompression (p≤0.009). CONCLUSION:: The SRS-Schwab classification provides a validated language to describe and categorize ASD. The present study demonstrates that the SRS-Schwab classification reflects severity of disease state based on multiple measures of HRQOL, and significantly correlates with the important decision of whether to pursue operative versus non-operative treatment.
    Neurosurgery 06/2013; · 3.03 Impact Factor
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    ABSTRACT: Study Design. Multicenter, prospective, consecutive series.Objective. Evaluate responsiveness of the SRS-Schwab adult spinal deformity (ASD) classification to changes in health-related quality of life (HRQOL) following treatment for ASD.Summary of Background Data. Ideally, a classification system should describe and be responsive to changes in a disease state. We hypothesized that the SRS-Schwab classification is responsive to changes in HRQOL measures following treatment for ASD.Methods. Multicenter, prospective, consecutive series from the International Spine Study Group (ISSG). Inclusion criteria: ASD, age>18, operative or non-operative treatment, baseline and one-year x-rays and HRQOL measures (Oswestry Disability Index [ODI], SRS-22, SF-36). The SRS-Schwab classification includes a curve descriptor and three sagittal spinopelvic modifiers (sagittal vertical axis [SVA], pelvic tilt [PT], pelvic incidence/lumbar lordosis mismatch [PI-LL]). Changes in modifiers at one year were assessed for impact on HRQOL from pre-treatment values based on minimal clinically important differences (MCID).Results. 341 patients met criteria (mean age = 54; 85% women; 177 operative and 164 non-operative). Change in PT modifier at one year follow-up was associated with changes in ODI and SRS-22 (total and appearance scores) (p≤0.034). Change in SVA modifier at one year was associated with changes in ODI, SF-36 PCS and SRS-22 (total, activity and appearance scores) (p≤0.037). Change in PI-LL modifier at one year was associated with changes in SF-36 PCS and SRS-22 (total, activity and appearance scores) (p≤0.03). Patients with improvement of PT, SVA, or PI-LL modifiers were significantly more likely to achieve MCID for ODI, SF-36 PCS (SVA and PI-LL only), SRS activity, and SRS pain (PI-LL only).Conclusions. The SRS-Schwab classification provides a validated system to evaluate ASD, and the classification components correlate with HRQOL measures. The current study demonstrates that the classification modifiers are responsive to changes in disease state and reflect significant changes in patient-reported outcomes.
    Spine 06/2013; · 2.45 Impact Factor
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    ABSTRACT: Study Design: Retrospective comparative cohort analysisObjective: To evaluate the effect of an intraoperative and ICU protocol on incidence of airway complications for patients undergoing combined anterior-posterior cervical decompression and fusion crossing the cervico-thoracic junction (CTAPF).Summary of Background Data: Airway compromise remains an important potential complication for patients undergoing CTAPF. Volume of intravenous fluid replacement perioperatively has been correlated with risk of airway complications in this patient population.Methods: A retrospective cohort study was performed comparing airway complications (postoperative airway edema requiring reintubation and/or prolonged need for intubation) in patients undergoing CTAPF prior to and following introduction of a standardized protocol. The protocol required limitation of crystalloid fluid resuscitation intraoperatively, with maintenance of blood pressure using vasopressors. Comparisons between the two cohorts included operative time, intraoperative blood loss, volume of IV fluid replacement, and incidence of airway complications and dysphagia.Results: Among patients operated prior to establishment of the protocol, 45% (9/20) experienced airway edema requiring extended intubation or reintubation. This rate was reduced to zero among eight patients operated following the adoption of the protocol (p = 0.029). Intraoperative IV fluid volumes were reduced from 6190 mL to 4802 mL after institution of the protocol (p = 0.016). EBL and total surgical time did not differ between the two cohorts (1024 ml vs. 869 ml, p = 0.443; and 6.76 hr vs. 7.18 hr, p = 0.460). Incidence of dysphagia was not significantly different between the two cohorts.Conclusion: Establishment of a fluid and airway management protocol for patients undergoing CTAPF reduced the incidence of prolonged intubation or re-intubation. Given the potentially life-threatening impact of loss of airway patency, intraoperative restriction of IV fluid while maintaining adequate blood pressure may be helpful in increasing the safety of surgical intervention in this complex patient population.
    Spine 05/2013; · 2.45 Impact Factor
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    ABSTRACT: Management of high-grade spondylolisthesis (HGS) remains challenging and is associated with significant controversies. The best surgical procedure remains debatable. Although the need for instrumentation is generally agreed upon, significant controversies still surround the role of reduction and anterior column support in the surgical management of HGS. Complications with operative management of HGS can be significant and often dictate the selection of surgical approach. This review highlights the pathophysiology, classification, clinical presentation, and management controversies of HGS, in light of recent advances in our understanding of the importance of sagittal spinopelvic alignment and technologic advancements.
    Neurosurgery clinics of North America 04/2013; 24(2):275-91. · 1.73 Impact Factor
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    ABSTRACT: Proximal junctional failure (PJF) should be distinguished from proximal junctional kyphosis, which is a recurrent deformity with limited clinical impact. PJF includes mechanical failure, and is a significant complication following adult spinal deformity surgery with potential for neurologic injury and increased need for surgical revision. Risk factors for PJF include age, severity of sagittal plane deformity, and extent of operative sagittal plane realignment. Techniques for avoiding PJF will likely require refinements in both perioperative and surgical strategies.
    Neurosurgery clinics of North America 04/2013; 24(2):213-8. · 1.73 Impact Factor
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    ABSTRACT: : Study Design: Prospective multi-center study evaluating operative (OP) vs. nonoperative (NON) treatment for adult spinal deformity (ASD).Objective: Evaluate correlations between spino-pelvic parameters and health related quality of life (HRQL) scores in ASD patients.Summary of Background Data: Sagittal spinal deformity is commonly defined by an increased sagittal vertical axis (SVA), however SVA alone may underestimate the severity of the deformity. Spino-pelvic parameters provide a more complete assessment of the sagittal plane but only limited data are available that correlate spino-pelvic parameters with disability.Methods: Baseline demographic, radiographic, and HRQOL data were obtained for all patients enrolled in a multicenter consecutive database. Inclusion criteria were: age >18 years and radiographic diagnosis of ASD. Radiographic evaluation was conducted on the frontal and lateral planes and HRQOL questionnaires (ODI, SRS-22r and SF-12) were completed. Radiographic parameters demonstrating highest correlation with HRQOL values were evaluated to determine thresholds predictive of ODI>40.Results: 492 consecutive ASD patients (mean age 51.9 years) were enrolled. Patients from the OP group (n = 178) were older (55 vs. 50.1 years, p<0.05), had greater SVA (5.5 vs. 1.7cm, p<0.05), greater pelvic tilt (PT; 22° vs. 11°, p<0.05) and greater pelvic incidence/ lumbar lordosis mismatch (PI-LL; 12.2 vs. 4.3; p<0.05) than NON group (n = 314). OP group demonstrated greater disability on all HRQOL measures compared to NON group (ODI = 41.4 vs. 23.9, p<0.05; SRS total = 2.9 vs. 3.5, p<0.05). Pearson analysis demonstrated that among all parameters, PT, SVA, and PI-LL correlated most strongly with disability for both OP and NON groups (p<0.001). Linear regression models demonstrated threshold radiographic spino-pelvic parameters for ODI>40 to be: PT≥22° (r = 0.38), SVA ≥47 mm (r = 0.47), PI-LL≥11 (r = 0.45).Conclusion: ASD is a disabling condition. Prospective analysis of consecutively enrolled ASD patients demonstrated that PT and PI-LL combined with SVA can predict patient disability and provide a guide for patient assessment for appropriate therapeutic decision-making. Threshold values for severe disability (ODI>40) included: PT≥22°, SVA ≥47mm, and PI-LL≥11°.
    Spine 03/2013; · 2.45 Impact Factor

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652 Citations
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  • 2014
    • University of Kansas
      Lawrence, Kansas, United States
  • 2002–2014
    • Oregon Health and Science University
      • • Department of Orthopaedics & Rehabilitation
      • • Department of Surgery
      Portland, Oregon, United States
  • 2013
    • University of California, San Diego
      • Department of Medicine
      San Diego, California, United States
  • 2010–2013
    • University of Virginia
      • Department of Neurosurgery
      Charlottesville, VA, United States
    • Clemenceau Medical Center
      Beyrouth, Beyrouth, Lebanon
    • University of Maryland, Baltimore
      • Department of Neurosurgery
      Baltimore, MD, United States
  • 2012
    • Virginia Department of Health
      Richmond, Virginia, United States
    • Alpert Medical School - Brown University
      • Department of Orthopaedics
      Providence, RI, United States
    • University of California, San Francisco
      • Department of Neurological Surgery
      San Francisco, CA, United States
  • 2011–2012
    • NYU Langone Medical Center
      • Department of Orthopaedic Surgery
      New York City, NY, United States
    • University of California, Davis
      • Department of Orthopaedic Surgery
      Davis, CA, United States
  • 2009
    • Rhode Island Hospital
      Providence, Rhode Island, United States
  • 2005
    • University of Michigan
      • Department of Orthopaedic Surgery
      Ann Arbor, MI, United States