Keith Bridwell

Dartmouth Medical School, Hanover, NH, USA

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Publications (24)64.57 Total impact

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    Article: Impact of magnitude and percentage of global sagittal plane correction on health-related quality of life at 2-years follow-up.
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    ABSTRACT: Sagittal plane malalignment has been established as the main radiographic driver of disability in adult spinal deformity (ASD). To evaluate the amount of sagittal correction needed for a patient to perceive improvement (minimal clinically important difference, MCID) in health-related quality of life (HRQOL) scores. This was a multicenter, retrospective analysis of prospectively consecutively enrolled ASD patients. Inclusion criterion was a sagittal vertical axis (SVA) >80 mm. Demographic, radiographic, and HRQOL preoperative and 2-year postsurgery data were collected. Surgical treatment was categorized based on SVA correction: <60 mm, 60 mm to 120 mm, and >120 mm. Changes in parameters were analyzed using paired t test, 1-way analysis of variance, and χ2 test. Seventy-six patients (preoperative SVA = 140 mm) were analyzed; each subgroup revealed significant HRQOL improvements following surgery. Compared with the <60 mm correction group, the likelihood of reaching MCID was significantly improved for the >120 mm group (Oswestry Disability Index) but not for the 60 mm to 120 mm group. A significantly greater likelihood of reaching MCID thresholds was observed for corrections above 66% of preoperative SVA. Best HRQOL outcomes for ASD patients with severe sagittal plane deformity were obtained with a correction >120 mm for SVA and at least 66% of correction. Although lesser amounts of SVA correction yielded clinical improvement, the rate of MCID threshold improvement was not significantly different for mild or modest corrections. These results underline the need for complete sagittal plane deformity correction if high rates of HRQOL benefit are sought for patients with marked sagittal plane deformity.
    Neurosurgery 05/2012; 71(2):341-8; discussion 348. · 2.79 Impact Factor
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    Article: Comparative effectiveness evidence from the spine patient outcomes research trial: surgical versus nonoperative care for spinal stenosis, degenerative spondylolisthesis, and intervertebral disc herniation.
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    ABSTRACT: Cost-effectiveness analysis of a randomized plus observational cohort trial. Analyze cost-effectiveness of Spine Patient Outcomes Research Trial data over 4 years comparing surgery with nonoperative care for three common diagnoses: spinal stenosis (SPS), degenerative spondylolisthesis (DS), and intervertebral disc herniation (IDH). Spine surgery rates continue to rise in the United States, but the safety and economic value of these procedures remain uncertain. Patients with image-confirmed diagnoses were followed in randomized or observational cohorts with data on resource use, productivity, and EuroQol EQ-5D health state values measured at 6 weeks, 3, 6, 12, 24, 36, and 48 months. For each diagnosis, cost per quality-adjusted life year (QALY) gained in 2004 US dollars was estimated for surgery relative to nonoperative care using a societal perspective, with costs and QALYs discounted at 3% per year. Surgery was performed initially or during the 4-year follow-up among 414 of 634 (65.3%) SPS, 391 of 601 (65.1%) DS, and 789 of 1192 (66.2%) IDH patients. Surgery improved health, with persistent QALY differences observed through 4 years (SPS QALY gain 0.22; 95% confidence interval, CI: 0.15, 0.34; DS QALY gain 0.34, 95% CI: 0.30, 0.47; and IDH QALY gain 0.34, 95% CI: 0.31, 0.38). Costs per QALY gained decreased for SPS from $77,600 at 2 years to $59,400 (95% CI: $37,059, $125,162) at 4 years, for DS from $115,600 to $64,300 per QALY (95% CI: $32,864, $83,117), and for IDH from $34,355 to $20,600 per QALY (95% CI: $4,539, $33,088). Comparative effectiveness evidence for clearly defined diagnostic groups from Spine Patient Outcomes Research Trial shows good value for surgery compared with nonoperative care over 4 years.
    Spine 11/2011; 36(24):2061-8. · 2.08 Impact Factor
  • Article: The Scoliosis Research Society Health-Related Quality of Life (SRS-30) age-gender normative data: an analysis of 1346 adult subjects unaffected by scoliosis.
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    ABSTRACT: Prospective, cross-sectional study. To determine Scoliosis Research Society (SRS)-30 health-related quality of life (HRQOL) reference values by age and gender in an adult population unaffected by scoliosis thereby allowing clinicians and investigators to compare individual and/or groups of spinal deformity patients to their generational peers. Normative data are collected to establish means and standard deviations of health-related quality of life outcomes representative of a population. The SRS HRQOL questionnaire has become the standard for determining and comparing treatment outcomes in spinal deformity practices. With the establishment of adult SRS-30 HRQOL population values, clinicians, and investigators now have a reference for interpretation of individual scores and/or the scores of subgroups of adult patients with spinal deformities. The SRS-30 HRQOL was issued prospectively to 1346 adult volunteers recruited from across the United States. Volunteers self-reported no history of scoliosis or prior spine surgery. Domain medians, means, confidence intervals, percentiles, and minimum/maximum values were calculated for six generational age-gender groups: male/female; 20-39, 40-59, and 60-80 years of age. Median and mean domain values ranged from 4.1 to 4.6 for all age-gender groups. The older the age-gender group, the lower (worse) the reported domain median and mean scores. The only exception was the mental health domain scores in the female groups which improved slightly. Males reported higher (better) scores than females but only the younger males were significantly higher in all domains than their female counterparts. In addition, all male groups reported higher Mental Health domain scores than their female counterparts (P=0.003). This study reports population medians, means, standard deviations, percentiles, and confidence intervals for the domains of the SRS-30 HRQOL instrument. Clinicians must be mindful of age-gender differences when assessing deformity populations. Generational decreases noted in the older adult volunteer scores may provide a basis for future investigators to interpret observed score decreases in patient cohorts at long-term follow-up.
    Spine 02/2011; 36(14):1154-62. · 2.08 Impact Factor
  • Article: Factors Affecting 4‐Year Cost‐Effectiveness of Surgery for Stenosis With or Without Degenerative Spondylolisthesis in the Spine Patient Outcomes Research Trial (Sport): 62
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    ABSTRACT: An abstract is unavailable. This article is available as HTML full text and PDF.
    Spine Journal Meeting Abstracts. 09/2010;
  • Article: Degenerative spondylolisthesis versus spinal stenosis: does a slip matter? Comparison of baseline characteristics and outcomes (SPORT).
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    ABSTRACT: As-treated analysis of the Spine Patient Outcomes Research Trial. To compare baseline characteristics and surgical and nonoperative outcomes between degenerative spondylolisthesis (DS) and spinal stenosis (SPS) patients. DS and SPS patients are often combined in clinical studies despite differences in underlying pathology and treatment. The DS cohort included 601 patients (369 [61%] underwent surgery), and the SPS cohort included 634 patients (394 [62%] underwent surgery). Baseline characteristics were compared between the 2 groups. Changes from baseline for surgical and nonoperative outcomes were compared at 1 and 2 years using longitudinal regression models. Primary outcome measures included the SF-36 bodily pain and physical function scores and the Oswestry Disability Index. The DS patients included more females (69% vs. 39%, P < 0.001), were older (66.1 year vs. 64.6 years, P = 0.021), and were less likely to have multilevel stenosis (35% vs. 61%, P < 0.001) compared with the SPS patients. There were no significant baseline differences on any of the main outcome measures. DS patients undergoing surgery were much more likely to be fused than SPS patients (94% vs. 11%, P < 0.001) and improved more with surgery than SPS patients on all primary outcome measures (DS vs. SPS): physical function (+30.4 vs. +25.3, P = 0.004 at 1 year; + 28.3 vs. +21.4, P < 0.001 at 2 years), bodily pain (+32.3 vs. +27.5, P = 0.006 at 1 year; +31.1 vs. +26.1, P = 0.003 at 2 years), and Oswestry Disability Index (-25.9 vs. -21.0, P < 0.001 at 1 year; -24.7 vs. -20.2, P < 0.001 at 2 years). Patients treated nonoperatively improved less than those treated surgically, and there were no significant differences in nonoperative outcomes between the 2 cohorts. Overall, DS and SPS patients had similar baseline characteristics. However, DS patients improved more with surgery than SPS patients. Future studies should probably not combine these heterogeneous patient populations.
    Spine 02/2010; 35(3):298-305. · 2.08 Impact Factor
  • Article: Comparison of surgical treatment in Lenke 5C adolescent idiopathic scoliosis: anterior dual rod versus posterior pedicle fixation surgery: a comparison of two practices.
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    ABSTRACT: Multicenter analysis of 2 groups of patients surgically treated for Lenke 5C adolescent idiopathic scoliosis (AIS). Compare patients with Lenke 5C scoliosis surgically treated with anterior spinal fusion with dual rod instrumentation and anterior column support with patients surgically treated with posterior release and pedicle screw instrumentation. Treatment of single, structural, lumbar, and thoracolumbar curves in patients with AIS has been the subject of some debate. Advocates of the anterior approach assert that their technique spares posterior musculature and may save distal fusion levels, and that with dual rods and anterior column support the issues with nonunion and kyphosis have been obviated. Advocates of the posterior approach assert that with the change to posterior pedicle screw based instrumentation that correction and levels are equivalent, and the posterior approach avoids the issues with nonunion and kyphosis. This report directly compares the results of posterior versus anterior instrumented fusions in the operative treatment of adolescent idiopathic Lenke 5C curves. We analyzed 62 patients with Lenke 5C based on radiographic and clinical data at 2 institutions: 31 patients treated with posterior, pedicle-screw instrumented fusions at 1 institution (group PSF); and 31 patients with anterior, dual-rod instrumented fusions at another institution (group ASF). Multiple clinical and radiographic parameters were evaluated and compared. The mean age, preoperative major curve magnitude, and preoperative lowest instrumented vertebral (LIV) tilt were similar in both groups (age: PSF = 15.5 years, ASF = 15.6 years; curve size: PSF = 50.3 degrees +/- 7.0 degrees , ASF = 49.0 degrees +/- 6.6 degrees ; LIV tilt: PSF = 27.5 degrees +/- 6.5 degrees , ASF = 27.8 degrees +/- 6.2 degrees ). After surgery, the major curve corrected to an average of 6.3 degrees +/- 3.2 degrees (87.6% +/- 5.8%) in the PSF group, compared with 12.1 degrees +/- 7.4 degrees (75.7% +/- 14.8%) in the ASF group (P < 0.01). At final follow-up, the major curve measured 8.0 degrees +/- 3.0 degrees (84.2% +/- 5.8% correction) in the PSF group, compared with 15.9 degrees +/- 9.0 degrees (66.6% +/- 17.9%) in the ASF group (P = 0.01). This represented a loss of correction of 1.7 degrees +/- 1.9 degrees (3.4% +/- 3.7%) in the PSF group, and 3.8 degrees +/- 4.2 degrees (9.4% +/- 10.7%) in the ASF group (P = 0.028). The LIV tilt decreased to 4.1 degrees +/- 3.4 degrees after surgery in the PSF group, and 4.5 degrees +/- 3.7 degrees in the ASF group. At final follow-up, the LIV tilt was 5.1 degrees +/- 3.5 degrees in the PSF group, and 4.5 degrees +/- 3.7 degrees in the ASF group. EBL was identical in both groups, and length of hospital stay was significantly (P < 0.01) shorter in the PSF group (4.8 vs. 6.1 days). There were no complications in either group which extended hospital stay or required an unplanned second surgery. At a minimum of 2-year follow-up, adolescents with Lenke 5C curves demonstrated statistically significantly better curve correction, less loss of correction over time, and shorter hospital stays when treated with a posterior release with pedicle screw instrumented fusion compared with an anterior instrumented fusion with dual rods for similar patient populations.
    Spine 09/2009; 34(18):1942-51. · 2.08 Impact Factor
  • Article: Risk factors and outcomes for catastrophic failures at the top of long pedicle screw constructs: a matched cohort analysis performed at a single center.
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    ABSTRACT: Retrospective review with matched-cohort analysis performed at a single institution. To determine risk factors and outcomes for acute fractures at the proximal aspect of long pedicle screw constructs. Acute fractures at the top of long segmental pedicle screw constructs (FPSC) can be catastrophic. Substantial surgical increase in lordosis may precipitate this problem. In relation to a matched cohort, we postulated that age, body mass index (BMI), and significant correction of lumbar lordosis would increase risk of FPSC and patients with FPSC would have lesser improvements in outcomes. Thirteen patients who sustained FPSC between 2000 and 2007 were evaluated. During this time, 264 patients aged 40 or older had a spinal fusion from the thoracic spine to the sacrum using an all-pedicle screw construct. A cohort of 31 of these patients without FPSC but with all pedicle screw constructs was matched for diagnosis of positive sagittal imbalance, gender, preoperative C7 sagittal plumb, and number of levels fused. There was a significant difference in age (P = 0.02) and BMI (P = 0.006) between the matched groups. There was no significant difference in preoperative/postoperative C7 plumb or change in lumbar lordosis between groups. Acute neurological deficit developed in 2 patients; both patients improved substantially after revision surgery. Nine patients underwent proximal extension of the fusion. For 7 of the 13 FPSC patients with bone mineral density data (BMD) available, average T score was-1.73; -0.58 for the matched group (10/31 with bone mineral density data) (P = 0.02). Factors that increased the risk of FPSC included obesity and older age. Osteopenia increased the risk as evidenced by BMD (based on 17 patients) and the older age of these patients. There was no statistical difference in clinical improvement between groups based on ODI, but the FPSC group did demonstrate a smaller improvement in ODI score than the matched cohort.
    Spine 09/2009; 34(20):2134-9. · 2.08 Impact Factor
  • Article: Operative versus nonoperative treatment of leg pain in adults with scoliosis: a retrospective review of a prospective multicenter database with two-year follow-up.
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    ABSTRACT: Retrospective review of a prospective, multicenter study. The purpose of this study was to assess the prevalence and severity of leg pain in adults with scoliosis and to assess whether surgery significantly improved leg pain compared with nonoperative management. Patients with adult scoliosis characteristically present with pain. The presence of leg pain is an independent predictor of a patient's choice for operative over nonoperative care. Data were extracted from a prospective, multicenter database for adult spinal deformity. At enrollment and follow-up, patients complete the Oswestry Disability Index (ODI) and assessment of leg pain using the numerical rating scale (NRS) score, with 0 and 10 representing no pain and unbearable pain, respectively. Plan for operative or nonoperative treatment was made at enrollment. The vast majority of adult scoliosis patients seen in our surgical clinics have received nonoperative therapies and are being seen for a surgical evaluation. Patients are counseled regarding operative and nonoperative management options and are in general encouraged to maximize nonoperative treatments. Two hundred eight (64%) of 326 adults with scoliosis had leg pain at presentation (mean NRS score = 4.7). Ninety-six patients with leg pain (46%) were managed operatively and 112 were treated nonoperatively. The operative group had higher baseline mean NRS score for leg pain (5.4 vs. 4.1, P < 0.001) and higher mean ODI (41 vs. 30, P < 0.001). At 2-year follow-up, nonoperative patients had no significant change in ODI or NRS score for leg pain (P = 0.2). In contrast, at 2-year follow-up surgically treated patients had significant improvement in mean NRS score for leg pain (5.4 vs. 2.2, P < 0.001) and ODI (41 vs. 24, P < 0.001). Compared with nonsurgically treated patients, at 2-year follow-up operative patients had lower mean NRS score for leg pain (2.2 vs. 3.8, P < 0.001) and mean ODI (24 vs. 31, P = 0.005). Despite having started with significantly greater leg pain and disability, surgically treated patients at 2-year follow-up had significantly less leg pain and disability than nonoperatively treated patients. Surgical treatment has the potential to provide significant improvement of leg pain in adults with scoliosis.
    Spine 07/2009; 34(16):1693-8. · 2.08 Impact Factor
  • Article: Improvement of Back Pain With Operative and Nonoperative Treatment in Adults With Scoliosis
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    ABSTRACT: OBJECTIVE: The purpose of this study was to assess whether back pain is improved with surgical treatment compared with nonoperative management in adults with scoliosis. METHODS: This is a retrospective review of a prospective, multicentered database of adults with spinal deformity. At the time of enrollment and follow-up, patients completed standardized questionnaires, including the Oswestry Disability Index (ODI) and Scoliosis Research Society 22 questionnaire (SRS-22), and assessment of back pain using a numeric rating scale (NRS) score, with 0 and 10 corresponding to no and maximal pain, respectively. The initial plan for surgical or nonoperative treatment was made at the time of enrollment. RESULTS: Of 317 patients with back pain, 147 (46%) were managed surgically. Compared with patients managed nonoperatively, operative patients had higher baseline mean NRS scores for back pain (6.3 versus 4.8; P < 0.001), higher mean ODI scores (35 versus 26; P < 0.001), and lower mean SRS-22 scores (3.1 versus 3.4; P < 0.001). At the time of the 2-year follow-up evaluation, nonoperatively managed patients did not have significant change in the NRS score for back pain (P = 0.9), ODI (P = 0.7), or SRS-22 (P = 0.9). In contrast, at the 2-year follow-up evaluation, surgically treated patients had significant improvement in the mean NRS score for back pain (6.3 to 2.6; P < 0.001), ODI score (35 to 20; P < 0.001), and SRS-22 score (3.1 to 3.8; P < 0.001). Compared with nonoperatively treated patients, at the time of the 2-year follow-up evaluation, operatively treated patients had a lower NRS score for back pain (P < 0.001) and ODI (P = 0.001), and higher SRS-22 (P < 0.001). CONCLUSIONS: Despite having started with significantly greater back pain and disability and worse health status, surgically treated patients had significantly less back pain and disability and improved health status compared with nonoperatively treated patients at the time of the 2-year follow-up evaluation. Compared with nonoperative treatment, surgery can offer significant improvement of back pain for adults with scoliosis.
    Neurosurgery 06/2009; 65(1):86-94. · 2.79 Impact Factor
  • Article: Surgical treatment of spinal stenosis with and without degenerative spondylolisthesis: cost-effectiveness after 2 years.
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    ABSTRACT: The SPORT (Spine Patient Outcomes Research Trial) reported favorable surgery outcomes over 2 years among patients with stenosis with and without degenerative spondylolisthesis, but the economic value of these surgeries is uncertain. To assess the short-term cost-effectiveness of spine surgery relative to nonoperative care for stenosis alone and for stenosis with spondylolisthesis. Prospective cohort study. Resource utilization, productivity, and EuroQol EQ-5D score measured at 6 weeks and at 3, 6, 12, and 24 months after treatment among SPORT participants. Patients with image-confirmed spinal stenosis, with and without degenerative spondylolisthesis. Time Horizon: 2 years. Societal. Nonoperative care or surgery (primarily decompressive laminectomy for stenosis and decompressive laminectomy with fusion for stenosis associated with degenerative spondylolisthesis). Cost per quality-adjusted life-year (QALY) gained. Among 634 patients with stenosis, 394 (62%) had surgery, most often decompressive laminectomy (320 of 394 [81%]). Stenosis surgeries improved health to a greater extent than nonoperative care (QALY gain, 0.17 [95% CI, 0.12 to 0.22]) at a cost of $77,600 (CI, $49,600 to $120,000) per QALY gained. Among 601 patients with degenerative spondylolisthesis, 368 (61%) had surgery, most including fusion (344 of 368 [93%]) and most with instrumentation (269 of 344 [78%]). Degenerative spondylolisthesis surgeries significantly improved health versus nonoperative care (QALY gain, 0.23 [CI, 0.19 to 0.27]), at a cost of $115,600 (CI, $90,800 to $144,900) per QALY gained. RESULT OF SENSITIVITY ANALYSIS: Surgery cost markedly affected the value of surgery. The study used self-reported utilization data, 2-year time horizon, and as-treated analysis to address treatment nonadherence among randomly assigned participants. The economic value of spinal stenosis surgery at 2 years compares favorably with many health interventions. Degenerative spondylolisthesis surgery is not highly cost-effective over 2 years but could show value over a longer time horizon.
    Annals of internal medicine 01/2009; 149(12):845-53. · 16.73 Impact Factor
  • Article: The use of traction in the treatment of severe spinal deformity.
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    ABSTRACT: Multicenter, retrospective, nonrandomized comparison group study of patients with severe scoliosis and kyphosis treated after 1995 with halo-gravity traction and without halo-gravity traction before definitive fusion. Compare surgical correction of severe spine deformity with preoperative halo traction and without preoperative traction. Prior studies have demonstrated that halo traction is a safe, well-tolerated method of applying gradual, sustained traction to maximize operative correction in patients with severe idiopathic scoliosis (IS) and kyphosis. However, these studies lack a comparison control group and study only a relatively small number of patients with IS. Fifty-three patients with severe scoliosis or kyphosis were studied using hospital records, standing preoperative, traction, postoperative, and final radiographs. Thirty were treated with traction and 23 were treated without traction. Patients within each group were analyzed based on demographics, diagnosis, perioperative, and radiographic data. In addition, patients were evaluated based on diagnosis, specifically whether patients had adolescent idiopathic scoliosis. Within the entire study population, there was no statistically significant difference in main coronal curve correction (62% vs. 59%), operative time, blood loss, and total complication rate (27% vs. 52%). However, the nontraction group underwent vertebral column resection more often (30% vs. 3%, P = 0.015). The traction group had a statistically significant increase in average hospital stay (36 vs. 14 days) (P = 0.011). Analysis of the 23 patients with adolescent idiopathic scoliosis also showed no statistically significant differences in curve correction, blood loss, or complications. Our study shows that patients with halo traction less frequently had a vertebral body resection, but achieved comparable deformity correction.
    Spine 11/2008; 33(21):2305-9. · 2.08 Impact Factor
  • Article: Bone morphogenetic protein (RhBMP-2) as a substitute for iliac crest bone graft in multilevel adult spinal deformity surgery: minimum two-year evaluation of fusion.
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    ABSTRACT: Prospective, single center, nonblinded radiographic analysis of anterior and posterior adult spinal deformity fusions performed with bone morphogenetic protein (rhBMP-2). To determine the ability of rhBMP-2 to achieve multilevel spinal fusion in the deformity patient. No previous study has evaluated rhBMP-2 for multilevel adult spinal deformity fusion with 2-year results. We postulated fusion could be achieved without distant autogenous graft harvest. Prospective analysis was performed for 98 patients (308 levels; mean age, 51.4 years) who underwent multilevel anterior or posterior spinal fusion (PSF) with minimum 2-year follow-up (average, 2.6 years). Group 1 (10 mg/level) contained 47 patients (109 levels; 2.33 levels/patient) who underwent anterior spinal fusion (ASF): BMP on an absorbable collagen sponge (ACS) with a titanium mesh cage. Group 2 (20 mg/level) included 43 patients (156 levels; 3.63 levels/patient) with PSF: BMP on an ACS with local bone graft (LBG) and bulking agent [tricalcium phosphate/hydroxyapatite (TCP-HA)]. Group 3 (40 mg/level) contained 8 patients (43 levels; 5.38 levels/patient) with PSF: rhBMP-2 and TCP-HA with no autologous bone. Confounding negative factors were present in the study population: medical comorbidities (26%), tobacco use (17%), revision surgery (34%), previous laminectomy (51%), and preoperative pseudarthrosis (27%). Postoperative films (AP, lateral, oblique) were evaluated by independent observers. Average fusion grade was based on a published scale. Overall fusion rate was 95%. (group 1 91%, group 2 97%, group 3 100%). No confounding factor demonstrated a detrimental statistical significance to fusion. In multilevel ASF, BMP (10 mg/level) generates fusion without autogenous bone. In multilevel PSF, BMP (20 mg/level) with LBG and TCP-HA produced fusion. BMP (40 mg/level) and TCP-HA without LBG achieved fusion. In multilevel spinal fusion, rhBMP-2 eliminated the necessity for iliac crest bone graft and yielded an excellent fusion rate.
    Spine 09/2008; 33(20):2153-9. · 2.08 Impact Factor
  • Article: Operative versus Conservative Treatment of Back Pain in Adults with Scoliosis: A Retrospective Review of a Prospective Multicenter Database with 2-year Follow-up: 819
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    ABSTRACT: An abstract is unavailable. This article is available as HTML full text and PDF.
    Neurosurgery 05/2008; 62(6):1406. · 2.79 Impact Factor
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    Article: Surgical rates and operative outcome analysis in thoracolumbar and lumbar major adult scoliosis: application of the new adult deformity classification.
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    ABSTRACT: Multicenter prospective consecutive clinical series. Investigate the interaction between the Adult Deformity Classification and treatment patterns, surgical strategies, surgery effectiveness, and complication rates. An Adult Deformity Classification has been established that applies radiographic parameters of disability. Preliminary intraobserver and interobserver analysis reveals excellent reliability of the classification. Outcomes studies have not been reported to date. A total of 784 adult patients with thoracolumbar or lumbar deformity underwent radiographic evaluation (full-length frontal/sagittal) as well as health assessment: Oswestry Disability Index, Scoliosis Research Society-22, and SF-12. Patients were subdivided by treatment and surgical strategies; 1 year (111 patients) and 2 year (45 patients) follow-up data were analyzed. Interaction between classification, treatment, surgical strategy, health assessment changes, and complications were analyzed. Classification modifiers (lordosis, subluxation, sagittal balance) were found to have significant variation (higher rates) in surgical care as the grade of the modifier increased. Classification differentiated patients by surgical approach and/or technique. Interaction between classification and baseline health assessment impacts both postoperative health scores and complication rates. This investigation appears to offer the first comprehensive analysis of classification, treatment, and outcomes in a large adult deformity patient group. Significant treatment patterns and outcomes are coming to light as is the impact of surgical strategy.
    Spine 12/2007; 32(24):2723-30. · 2.08 Impact Factor
  • Article: A clinical impact classification of scoliosis in the adult.
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    ABSTRACT: Multicenter, prospective, consecutive clinical series. To establish and validate classification of scoliosis in the adult. Studies of adult scoliosis reveal the impact of radiographic parameters on self-assessed function: lumbar lordosis and frontal plane obliquity of lumbar vertebrae, not Cobb angle, correlate with pain scores. Deformity apex and intervertebral subluxations correlate with disability. A total of 947 adults with spinal deformity had radiographic analysis: frontal Cobb angle, deformity apex, lumbar lordosis, and intervertebral subluxation. Health assessment included Oswestry Disability Index and Scoliosis Research Society instrument. Deformity apex, lordosis (T12-S1), and intervertebral subluxation were used to classify patients. Outcomes measures and surgical rates were evaluated. Mean maximal coronal Cobb was 46 degrees and lumbar lordosis 46 degrees . Mean maximal intervertebral subluxation (frontal plane) was 4.2 mm (sagittal plane, 1.2 mm). In thoracolumbar/lumbar deformities, the loss of lordosis/higher subluxation was associated with lower Scoliosis Research Society pain/function and higher Oswestry Disability Index scores. Across the study group, lower apex combined with lower lordosis led to higher disability. Higher surgical rates with decreasing lumbar lordosis and higher intervertebral subluxation were detected. A clinical impact classification has been established based on radiographic markers of disability. The classification has shown correlation with self-reported disability as well as rates of operative treatment.
    Spine 09/2006; 31(18):2109-14. · 2.08 Impact Factor
  • Article: Nonsurgical resource utilization in adult spinal deformity.
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    ABSTRACT: The enrollment data were retrospectively reviewed for 1,061 patients entered into a prospective multicenter study of adult spinal deformity between January 2002 and June 2004. The purpose of this study is to quantify and analyze the use of nonsurgical resources in patients with adult spinal deformity. Limited data exist regarding the utilization of nonsurgical treatment methods for adult spinal deformity. Demographic data, surgical history, symptom assessment, and nonsurgical treatment regimen were reviewed. Health status measures were the SF-12, SRS-29, and ODI. Nonsurgical patients were divided into low- and high-symptom subgroups based on age adjusted ODI score. Resource utilization was analyzed based on both patient and physician questionnaire responses. High- and low-symptom nonsurgical subgroups differed significantly on all reported health status measures (P < 0.0001). High-symptom patients used greater resources in terms of narcotics, epidural blocks, and physical agent methods (P < 0.001), analgesics (P < 0.01), pain management referral and bed rest (P < 0.02), strength training, nerve root blocks, and stabilization exercises (P < 0.05). The results of this study demonstrate that, within the population of adult deformity patients, distinct high- and low-symptom groups exist and can be clearly identified. While high-symptom patients used significantly greater resources, most low-symptom patients used nonsurgical resources as well.
    Spine 05/2006; 31(8):941-7. · 2.08 Impact Factor
  • Article: Summary statement: innovative technologies for traditional scoliosis surgery.
    Peter O Newton, George Thompson, Keith Bridwell
    Spine 10/2005; 30(17 Suppl):S92-3. · 2.08 Impact Factor
  • Article: The impact of positive sagittal balance in adult spinal deformity.
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    ABSTRACT: This study is a retrospective review of 752 patients with adult spinal deformity enrolled in a multicenter prospective database in 2002 and 2003. Patients with positive sagittal balance (N = 352) were further evaluated regarding radiographic parameters and health status measures, including the Scoliosis Research Society patient questionnaire, MOS short form-12, and Oswestry Disability Index. To examine patients with adult deformity with positive sagittal balance to define parameters within that group that might differentially predict clinical impact. In a multicenter study of 298 adults with spinal deformity, positive sagittal balance was identified as the radiographic parameter most highly correlated with adverse health status outcomes. Radiographic evaluation was performed according to a standardized protocol for 36-inch standing radiographs. Magnitude of positive sagittal balance and regional sagittal Cobb angle measures were recorded. Statistical correlation between radiographic parameters and health status measures were performed. Potentially confounding variables were assessed. Positive sagittal balance was identified in 352 patients. The C7 plumb line deviation ranged from 1 to 271 mm. All measures of health status showed significantly poorer scores as C7 plumb line deviation increased. Patients with relative kyphosis in the lumbar region had significantly more disability than patients with normal or lordotic lumbar sagittal Cobb measures. This study shows that although even mildly positive sagittal balance is somewhat detrimental, severity of symptoms increases in a linear fashion with progressive sagittal imbalance. The results also show that kyphosis is more favorable in the upper thoracic region but very poorly tolerated in the lumbar spine.
    Spine 10/2005; 30(18):2024-9. · 2.08 Impact Factor
  • Article: Correlation of radiographic parameters and clinical symptoms in adult scoliosis.
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    ABSTRACT: This study is a retrospective review of the initial enrollment data from a prospective multicentered study of adult spinal deformity. The purpose of this study is to correlate radiographic measures of deformity with patient-based outcome measures in adult scoliosis. Prior studies of adult scoliosis have attempted to correlate radiographic appearance and clinical symptoms, but it has proven difficult to predict health status based on radiographic measures of deformity alone. The ability to correlate radiographic measures of deformity with symptoms would be useful for decision-making and surgical planning. The study correlates radiographic measures of deformity with scores on the Short Form-12, Scoliosis Research Society-29, and Oswestry profiles. Radiographic evaluation was performed according to an established positioning protocol for anteroposterior and lateral 36-inch standing radiographs. Radiographic parameters studied were curve type, curve location, curve magnitude, coronal balance, sagittal balance, apical rotation, and rotatory subluxation. The 298 patients studied include 172 with no prior surgery and 126 who had undergone prior spine fusion. Positive sagittal balance was the most reliable predictor of clinical symptoms in both patient groups. Thoracolumbar and lumbar curves generated less favorable scores than thoracic curves in both patient groups. Significant coronal imbalance of greater than 4 cm was associated with deterioration in pain and function scores for unoperated patients but not in patients with previous surgery. This study suggests that restoration of a more normal sagittal balance is the critical goal for any reconstructive spine surgery. The study suggests that magnitude of coronal deformity and extent of coronal correction are less critical parameters.
    Spine 04/2005; 30(6):682-8. · 2.08 Impact Factor
  • Article: Spine/SRS spondylolisthesis summary statement.
    Spine 04/2005; 30(6 Suppl):S3. · 2.08 Impact Factor

Institutions

  • 2009–2011
    • Dartmouth Medical School
      • Institute for Health Policy and Clinical Practice
      Hanover, NH, USA
  • 2006
    • University of Louisville
      • Department of Orthopaedic Surgery
      Louisville, KY, USA
  • 2005
    • Washington University in St. Louis
      • Department of Orthopaedic Surgery
      Saint Louis, MO, USA
  • 2003
    • Saint Joseph Hospital
      Chicago, IL, USA