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Study Design: A retrospective review of pediatric kyphosis patients undergoing a spinal cord-level osteotomy for correction. Objective: To evaluate the prevalence, etiology, timing, and intervention related to loss of spinal cord monitoring data during surgical correction of pediatric kyphosis in the spinal cord region. Summary Of Background Data: Although much has been written regarding the risks inherent to scoliosis surgery, there is less literature available regarding the neurologic outcomes of pediatric kyphosis surgery. As more surgeons contemplate posterior-only kyphosis correction with spinal cord-level osteotomies, the importance of maintaining spinal cord neurologic function is paramount. Methods: Forty-two patients with pediatric kyphosis undergoing a posterior-only spinal reconstruction with a spinal cord level osteotomy or posterior-based vertebral column resection performed were reviewed. Patients were categorized by diagnosis, type and incidence of osteotomies, and loss of neurogenic mixed-evoked potential (NMEP) data. Interventions required to regain data and postoperative neurologic outcomes were also reviewed. Results: Of the 42 patients, 9 (21.4%) demonstrated a complete loss of NMEP data sometime during surgery while concomitant somatosensory sensory-evoked potentials (SSEP) remained within acceptable limits of baseline values. All 9 patients had intraoperative intervention including: blood pressure elevation (n = 1), release of corrective forces (n = 2), blood pressure elevation and correction release (n = 3), malalignment/subluxation adjustment (n = 1), further bony decompression (n = 1), or restoration of anterior column height via a titanium cage along with further posterior decompression (n = 1). In all cases, SSEPs were unchanged and NMEPs returned varying from 8 to 20 minutes after loss, with all patients having a normal wake-up test intraoperatively and a normal neurologic examination after surgery. Conclusion: Intraoperative multimodality monitoring with some form of motor tract assessment is a fundamental component of kyphosis correction surgery in the spinal cord region in order to create a safer, optimal environment and to minimize neurologic deficit. The surgeon must be able to trust the information monitoring provides and act on it accordingly. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective review. Objective: To determine the reliability of supine long-cassette radiographs as compared with side-bending films in predicting curve flexibility in operative cases of adolescent idiopathic scoliosis (AIS). Summary Of Background Data: The value of side-bending films is important in the classification of AIS, as well as predicting curve flexibility. Methods: A total of 675 patients with a diagnosis of operative AIS were evaluated. All curves were classified by the Lenke classification. Coronal parameters included: proximal thoracic (PT), main thoracic (MT), and thoracolumbar/lumbar (TL/L) Cobb measurements; sagittal data including: T2-T5, T5-T12, and TL/L measurements. Curves were divided into Lenke Types 1 (N = 263), 2 (N = 118), 3 (N = 52), 4 (N = 31), 5 (N = 57), and 6 (N = 54). Lenke Types 1 to 4 (Group I-MT Major) were compared with Types 5 and 6 (Group II-TL/L Major). Results: For Group I, MT supine films were highly predictive of MT side-bending while TL/L supine films were highly predictive of TL/L side-bending and standing films. An equation was derived to predict the value of the side-bending radiographs for each part of the curve. For Group II, MT supine films were highly predictive of MT side-bending and standing films. TL/L supine films were highly predictive of TL/L side-bending and standing films. Contingency table analysis for Group I resulted in the supine film providing a strong statistical ability to predict a nonstructural PT curve (sensitivity = 0.952, PPV = 0.864, NPV = 0.865) and also a nonstructural TL/L curve (sensitivity = 0.958, PPV = 0.916). Similarly, in Group II, we found a strong statistical ability to predict a nonstructural PT (sensitivity 1.00, PPV = 0.982, NPV = 1.00) and a nonstructural MT curve (sensitivity 0.789, specificity = 0.842, PPV = 0.833, NPV = 0.80). Conclusion: A single preoperative supine radiograph is highly predictive of side-bending radiographs and can be used as an adjunct to predicting curve type, flexibility, and structurality. Thus, this singular, reproducible, and non-effort-related radiograph can potentially replace the need for dual side-bending films. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective radiographic outcomes analysis. Objective: We had 3 hypotheses: 1) a longer fusion; 2) a more proximal instrumented vertebra, and 3) circumferential fusion versus posterior-only fusion would increase the likelihood of adjacent segment disease (ASD). Summary Of Background Data: The literature analyzing risk factors, prevalence, and presentation of patients with ASD is varied and without clear consensus. Methods: A total of 188 patients with minimum 5-year follow-up who had lumbar/thoracolumbar fusion with pedicle screw instrumentation for degenerative disorders were included. Radiographic ASD was defined by: 1) development of spondylolisthesis >4 mm, 2) segmental kyphosis >10 degrees , 3) complete collapse of disc space, or 4) more than 2 grades worsening of Weiner classification. Clinical ASD was defined as 1) symptomatic spinal stenosis, 2) intractable back pain, or 3) subsequent sagittal or coronal imbalance. Results: Radiographic ASD occurred in 42.6% (80 of 188) of patients. Patients with radiographic ASD had worse Oswestry scores (20.3 vs. 12.5; P = 0.001) at ultimate follow-up than those without ASD. Clinical ASD developed in 30.3% (57 of 188) of patients. Clinical ASD manifested as spinal stenosis (n = 47), instability-type back pain (n = 5), and sagittal or coronal imbalance (n = 5). Age at surgery over 50 years and length of fusion were significant risk factors for the development of ASD in the lumbar spine. Fusion to L1-L3 proximally increased the risk of ASD when compared with L4 and L5. Circumferential fusion versus posterior fusion was not a significant factor in the development of ASD. Conclusion: Patients over the age of 50 were at higher risk of developing clinical ASD than those 50 years old or younger. Length of fusion was a significant risk factor in the development of ASD in the lumbar spine. Fusion up to L1-L3 increased the risk of ASD when compared with L4 and L5. Circumferential fusion, as opposed to posterolateral fusion, was not a statistically significant risk factor for the development of ASD. [ABSTRACT FROM AUTHOR]

Adult spinal deformity (ASD) is one of the most challenging spinal disorders associated with broad range of clinical and radiological presentation. Correct selection of fusion levels in surgical planning for the management of adult spinal deformity is a complex task. Several classification systems and algorithms exist to assist surgeons in determining the appropriate levels to be instrumented. In this study, we describe our new simple decision making algorithm and selection of fusion level for ASD surgery in terms of adult idiopathic idiopathic scoliosis vs. degenerative scoliosis.

Objective: To improve pedicle screw placement accuracy with minimal radiation and low cost, we developed specially designed K-wire with a marker. To evaluate the accuracy of thoracolumbar pedicle screws placed using the novel guide-pin and portable X-rays., Methods: Observational cohort study with computerized tomography (CT) analysis of in vivo and in vitro pedicle screw placement. Postoperative CT scans of 183 titanium pedicle screws (85 lumbar and 98 thoracic from T1 to L5) placed into 2 cadavers and 18 patients were assessed. A specially designed guide-pin with a marker was inserted into the pedicle to identify the correct starting point (2 mm lateral to the center of the pedicle) and aiming point (center of the pedicle isthmus) in posteroanterior and lateral X-rays. After radiographically confirming the exact starting and aiming points desired, a gearshift was inserted into the pedicle from the starting point into the vertebral body through the center of pedicle isthmus., Results: Ninety-nine percent (181/183) of screws were contained within the pedicle (total 183 pedicle screws : 98 thoracic pedicle screws and 85 lumbar screws). Only two of 183 (1.0%) thoracic pedicle screws demonstrated breach (1 lateral in a patient and 1 medial in a cadaver specimen). None of the pedicle breaches were associated with neurologic or other clinical sequelae., Conclusion: A simple, specially designed guide-pin with portable X-rays can provide correct starting and aiming points and allows for accurate pedicle screw placement without preoperative CT scan and intraoperative fluoroscopic assistance.

Study Design: Retrospective study with prospectively collected outcomes data., Objective: Determine the significance of coronal balance on spinal deformity surgery outcomes., Summary of Background Data: Sagittal balance has been confirmed as an important radiographic parameter correlating with adult deformity treatment outcomes. The significance of coronal balance on functional outcomes is less clear., Methods: Eighty-five patients with more than 4 cm of coronal imbalance who underwent reconstructive spinal surgery were evaluated to determine the significance of coronal balance on functional outcomes as measured with the Oswestry Disability Index (ODI) and Scoliosis Research Society outcomes questionnaires. Sixty-two patients had combined coronal (>4 cm) and sagittal imbalance (>5 cm), while 23 patients had coronal imbalance alone., Results: Postoperatively, 85% of patients demonstrated improved coronal balance. The mean improvement in the coronal C7 plumb line was 26 mm for a mean correction of 42%. The mean preoperative sagittal C7 plumb line in patients with combined coronal and sagittal imbalance was 118 mm (range, 50-310 mm) and improved to a mean 49 mm. The mean preoperative and postoperative ODI scores were 42 (range, 0-90) and 27 (range, 0-78), for a mean improvement of 15 (36%) (P = 0.00001; 95% CI, 12-20). The mean Scoliosis Research Society scores improved by 17 points (29%) (P = 0.00). Younger age (P = 0.008) and improvement in sagittal balance (P = 0.014) were positive predictors for improved ODI scores. Improvement in sagittal balance (P = 0.010) was a positive predictor for improved Scoliosis Research Society scores. In patients with combined coronal and sagittal imbalance, improvement in sagittal balance was the most significant predictor for improved ODI scores (P = 0.009). In patients with preoperative coronal imbalance alone, improvement in coronal balance trended toward, but was not a significant predictor for improved ODI (P = 0.092)., Conclusion: Sagittal balance improvement is the strongest predictor of improved outcomes in patients with combined coronal and sagittal imbalance. In patients with coronal imbalance alone, improvement in coronal balance was not a factor for predicting improved functional outcomes.

Study Design:  Retrospective cohort study., Objective:  To analyze the surgical results of a group of patients older than 65 years treated for mild degenerative lumbar scoliosis (<30°) with stenosis, treated with decompression alone or decompression and limited fusion., Methods:  We evaluated 55 patients, all older than 65 years from our prospectively collected database with mild degenerative scoliosis (<30°) and stenosis who underwent surgery. Laminectomy alone was performed in 16 patients, and laminectomy and limited fusion in 39 patients. Mean follow-up was 4.6 years in the decompression group and 5.0 years in the fusion group. Clinical results were graded by patients' self-reported satisfaction and length of symptom-free period to recurrence., Results:  In the decompression alone group, 6 (37%) of 16 patients developed recurrent stenosis at the previously decompressed level and five developed recurrence within 6 months postoperatively versus the decompression and fusion group where 3 (8%) of 39 (P = .0476) developed symptomatic stenosis supra adjacent to the fusion. Of 16 patients in the decompression alone group, 12 (75%) had recurrence of symptoms by the 5-year follow-up period versus only 14 (36%) patients in the decompression and fusion group (P = .016). Adjacent segment degenerative changes were common in the fusion group, but only 7% developed symptomatic stenosis., Conclusions:  Decompression with limited fusion prevents early return of stenotic symptoms compared with decompression alone in the setting of mild degenerative scoliosis (<30°) and symptomatic stenosis in patients 65 years and older. [Table: see text] The definiton of the different classes of evidence is available on page 67.

Thoracic pedicle screw fixation techniques are still controversial for thoracic deformities because of possible complications including neurologic deficit. Methods to aid the surgeon in appropriate screw placement have included the use of intraoperative fluoroscopy and/or radiography as well as image-guided techniques. We describe our technique for free hand pedicle screw placement in the thoracic spine without any radiographic guidance and present the results of pedicle screw placement analyzed by computed tomographic scan in two human cadavers. This free hand technique of thoracic pedicle screw placement performed in a step-wise, consistent, and compulsive manner is an accurate, reliable, and safe method of insertion to treat a variety of spinal disorders, including spinal deformity.

Background: Instrumented circumferential fusion has been used as a primary and salvage procedure in lumbar spine fusion, especially for adult low-grade isthmic spondylolisthesis. Recently, instrumented anterior lumbar interbody fusion (ALIF) has been shown to provide good clinical and radiologic results that are comparable with those attained with traditional lumbar fusion. However, there have been no reports available that compare instrumented circumferential fusion with instrumented ALIF., Methods: Between January 2003 and November 2004, a total of 43 consecutive patients underwent instrumented ALIF (group I) at one hospital of the authors. Between February 2003 and October 2006, a total of 32 consecutive patients underwent instrumented circumferential fusion (group II) at the other hospital of the authors. The authors retrospectively reviewed clinical and radiologic data from patients. The time spent on the operation, blood loss, blood transfusions, the length of hospital stay, complications, clinical results, and radiologic results, including disc height (DH), degree of listhesis, segmental lordosis (SL), and whole lumbar lordosis (WL), were analyzed and compared. Clinical outcomes were graded using visual analog scale (VAS) scores. Functional outcomes were measured using Oswestry Disability Index (ODI) scores and return-to-work status., Results: The mean follow-up period was 41.1 and 32.9 months in group I and group II, respectively. Radiologic evidence of fusion was noted in 42 of 43 patients in group I and in 32 of 32 patients in group II. In both groups, all of the radiologic data, including the DH, degree of listhesis, SL, and WL significantly changed from the preoperative to postoperative period except for WL in group II. In both groups, VAS scores for back and leg pain and ODI scores significantly changed from the preoperative to postoperative period. There was no significant difference for VAS scores for back ODI scores in the two treatment groups after surgery. The mean time until return to work was 3.7 months in group I and 3.6 months in group II (p < .05). The mean hospital stay for group I (7.4 days) was shorter than that for group II (15.2 days) (p < .05). The mean operation time in group I (190 minutes) was shorter than that in group II (260.8 minutes) (p < .05). The mean blood loss in group I (300 mL) was less than that in group II (379 mL) (p < .05)., Conclusions: According to the present clinical outcome, instrumented ALIF is at least as effective as instrumented circumferential fusion for the treatment of back pain in adult patients with low-grade isthmic spondylolisthesis. Moreover, in terms of operative data including the duration of operation and hospital stay, as well as blood loss, instrumented ALIF demonstrates better results., (Copyright © 2010 Elsevier Inc. All rights reserved.)

Study Design: A comparative study., Objective: To report a preliminary evaluation of the Scoliosis Research Society Outcomes Instrument (SRS-24) and determine whether differences in baseline scores exist between American and Japanese patients with idiopathic scoliosis., Summary of Background Data: Because the SRS outcomes instrument was primarily introduced for the American population, baseline scores in the Japanese population might differ from the American population. A comparative study using the SRS instrument between American and Japanese patients with idiopathic scoliosis has not been reported., Methods: Two comparable groups of 100 idiopathic scoliosis patients before spinal fusion were separated into American (A) and Japanese (J). There were no statistically significant differences between the groups for gender (A: 9 men/91 women vs. J: 13 men/87 women), age (A: 15.0 +/- 2.4 vs. J: 14.9 +/- 3.8), main curve location (A: 77 thoracic/23 lumbar, J: 76 thoracic/24 lumbar), main curve Cobb angle (A: 50.5 +/- 5.2 vs. J: 51.1 +/- 8.7), and thoracic kyphosis (A: 20.9 +/- 14.3 vs. J: 19.9 +/- 12.1) (P > 0.05, for all comparisons). Patients were evaluated using the first section of the SRS-24 which was divided into 4 domains: total pain, general self-image, general function, and activity. SRS-24 scores were statistical compared in individual domains and questions using the Mann-Whitney U test., Results: American patients had significantly lower scores in pain (P < 0.0001, A: 3.7 +/- 0.8 vs. J: 4.3 +/- 0.4), function (P < 0.01, A: 3.9 +/- 0.6 vs. J: 4.2 +/- 0.5), and activity (P < 0.0001, A: 4.5 +/- 0.8 vs. J: 4.9 +/- 0.3) domains compared with Japanese patients. Japanese patients had significantly lower scores in the self-image (P < 0.0001, A: 4.0 +/- 0.7 vs. J: 3.5 +/- 0.5) domain. With regard to individual questions, there were significant differences in the scores between the 2 groups for all questions except 5 and 13 (P < 0.05, for all comparisons)., Conclusion: SRS-24 scores in the Japanese idiopathic scoliosis population differed from that of the American population. Japanese patients had less back pain, a negative self-image regarding back deformity, higher general physical function, and daily activity. It is highly probable that patient's perceptions differ due to cultural differences, which affect SRS-24 scores so a cross-cultural comparison of the SRS instrument content is necessary in the future.

Study Design: Retrospective, case-control, matched cohort., Objective: Compare the radiographic and clinical outcomes of adult spinal deformity patients treated with thoracic pedicle screw (TPS) or thoracic hook constructs., Summary of Background Data: The efficacy of TPS instrumentation for pediatric spinal deformity correction has been established. Little is known about TPS use in adult spinal deformity., Methods: Fifty-six patients (average age, 49 years; average follow-up, 3.58 years) were treated with TPS or thoracic hook constructs for coronal (n = 20) or sagittal (n = 36) plane deformities. Patients were evaluated radiographically and with SRS scores., Results: Coronal deformities treated with TPS demonstrated improved main thoracic curve correction compared with hook constructs at last follow-up (24.8 degrees vs. 13.8 degrees; P < 0.05), despite having larger (59.8 degrees vs. 44.9 degrees; P < 0.05) and more rigid preoperative curves (29.3% vs. 44.9% correction on side-bending radiographs; P < 0.001). Sagittal deformities treated with TPS constructs demonstrated greater thoracolumbar kyphosis correction than hook constructs at last follow-up (12.1 degrees vs. 2.5 degrees; P < 0.05). No TPS patient had a thoracic pseudarthrosis. Four hook patients (14%) had thoracic pseudarthroses., Conclusions: TPS instrumentation allows greater coronal and sagittal plane correction and may reduce the risk of thoracic pseudarthrosis compared with hook constructs when treating adult spinal deformities.

Study Design: Retrospective study., Objective: To analyze the causes, prevalence of, and risk factors for sagittal thoracic decompensation in adult lumbar spinal instrumentation and fusion (from distal thoracic or upper lumbar spine) to L5 or S1., Summary of Background Data: To our knowledge, no studies on sagittal thoracic decompensation following long adult lumbar spinal instrumentation and fusion (from distal thoracic or upper lumbar spine) to L5 or S1 have been published., Methods: A clinical and radiographic assessment of 99 patients with adult lumbar spinal deformity (average age 56.7 years) who underwent long (> or = 4 vertebrae; range 4-10/average 6.7) spinal instrumentation and fusion (from lower thoracic or upper lumbar spine to L5 or S1) at a single institution between 1985 and 2003 with a minimum 2-year follow-up (average 4.5 years) was performed. We defined sagittal thoracic decompensation as a progressive kyphotic deformity of the thoracic spine without pseudarthrosis after a long lumbar fusion, which subsequently resulted in a C7 plumb relative to the posterior aspect of the L5-S1 disc > or = 8 cm., Results: The prevalence of sagittal thoracic decompensation after long adult lumbar spinal instrumentation and fusion (from distal thoracic or upper lumbar spine) to L5 or S1 was 23% (23/99 cases). The etiologies were 14 acute sharp angular kyphoses and 9 long sweeping kyphoses above the instrumented fusion. Of the 14 sharp angular kyphoses, 10 occurred from severe disc degeneration and 4 were caused by compression fractures at the uppermost instrumented vertebra., Conclusion: Risk factors for sagittal thoracic decompensation developing were sagittal imbalance at 8 weeks postoperatively (> or = 5 cm), smaller lumbar lordosis compared with thoracic kyphosis (< 10 degrees) at 8 weeks postoperatively, preoperative sagittal imbalance (> or = 5 cm), age at surgery (older than 55 years), and associated comorbidities. Sagittal thoracic decompensation adversely affected Scoliosis Research Society 24 outcomes scores.

Study Design: A retrospective study., Objective: To determine factors controlling sagittal spinal balance after long adult lumbar instrumentation and fusion from the thoracolumbar spine to L5 or S1., Summary of Background Data: To our knowledge, no study on postoperative sagittal balance following long adult spinal instrumentation and fusion to L5 or S1 has been published., Methods: A clinical and radiographic assessment of 80 patients with adult lumbar deformity (average age 53.4 years) who underwent long (average 7.6 vertebrae, 5-11 vertebrae) segmental posterior spinal instrumentation and fusion from the thoracolumbar spine to the L5-S1 (average 4.5 years, 2-15.8-year follow-up) was performed. We defined the optimal sagittal balance (n = 42) group, the distance from C7 plumb to superior posterior endplate of S1 < or = 3.0 cm, and the suboptimal sagittal balance (n = 38) group, the distance from C7 plumb to superior posterior endplate of S1 > 3.0 cm at ultimate follow-up., Results: The optimal sagittal balance group (C7 plumb, average -0.6 +/- 2.5 cm) had the larger average angle differences between lumbar lordosis and thoracic kyphosis (P < 0.0001), preoperative smaller pelvic incidence (P = 0.007), smaller average thoracolumbar junctional angle (T10-L2) increase (P < 0.0001), and bigger lumbar lordosis angle increase (P = 0.014) at ultimate follow-up. Patients with optimal sagittal balance at ultimate follow-up had significantly higher total Scoliosis Research Society 24 outcome scores than those with suboptimal sagittal balance (P = 0.015). Risk factors that were statistically significant for the suboptimal sagittal balance group included pelvic incidence compared with lumbar lordosis (> or = 45 degrees) before surgery (vs. < 45 degrees, P = 0.009), smaller lumbar lordosis compared with thoracic kyphosis (< 20 degrees) at 8 weeks postoperatively (vs. > or = 20 degrees, P = 0.013), and older than 55 years of age at surgery (vs. 55 years or younger, P = 0.024)., Conclusion: A sagittal Cobb angle difference between lumbar lordosis and thoracic kyphosis of > 20 degrees (higher lumbar lordosis) is advisable in most circumstances to achieve optimal sagittal balance.

Study Design: Retrospective study., Objective: To analyze the incidence of and risk factors for pseudarthrosis in long adult spinal instrumentation and fusion to S1., Summary of Background Data: Few studies on pseudarthrosis in long adult spinal instrumentation and fusion to S1 exist., Methods: A clinical and radiographic assessment of 144 adult patients with spinal deformity (average age 52.0 years; range 21.1-77.6) who underwent long (5-17 vertebrae, average 11.9) spinal instrumentation and fusion to the sacrum at a single institution between 1985 and 2002, with a minimum 2-year follow-up (average 3.9; range 2-14) was performed., Results: Of 144 patients, 34 (24%) had pseudarthroses. There were 17 patients who had pseudarthroses at T10-L2 and 15 at L5-S1. A total of 24 patients (71%) presented with multiple levels involved (2-6). Pseudarthrosis was most commonly detected within 4 years postoperatively (31 patients; 94%). Factors that statistically increased the risk of pseudarthrosis were: thoracolumbar kyphosis (T10-L2 > or = 20 degrees vs. < 20 degrees, P < 0.0001); osteoarthritis of the hip joint (P = 0.002); thoracoabdominal approach (vs. paramedian approach, P = 0.009); positive sagittal balance > or = 5 cm at 8 weeks postoperatively (vs. < or = 5 cm, P = 0.012); age at surgery older than 55 years (vs. 55 years or younger, P = 0.019); and incomplete sacropelvic fixation (vs. complete sacropelvic fixation, P = 0.020). Fusion from upper thoracic spine (T2-T5) did not statistically increase the pseudarthrosis rate compared to lower thoracic spine (T9-T12) (P = 0.20). Patients with pseudarthrosis had significantly lower Scoliosis Research Society 24 outcome scores (average score 71/120) than those without (average score 90/120; P < 0.0001) at ultimate follow-up., Conclusion: The overall prevalence of pseudarthrosis following long adult spinal deformity instrumentation and fusion to S1 was 24%. Thoracolumbar kyphosis, osteoarthritis of the hip joint, thoracoabdominal approach (vs. paramedian approach), positive sagittal balance > or = 5 cm at 8 weeks postoperatively, older age at surgery (older than 55 years), and incomplete sacropelvic fixation significantly increased the risks of pseudarthrosis to an extent that was statistically significant. Scoliosis Research Society 24 outcomes scores at ultimate follow-up were adversely affected when pseudarthrosis developed.

Study Design: A retrospective matched cohort study., Objective: To comprehensively compare the 2-year postoperative results of posterior correction and fusion with segmental pedicle screw instrumentation versus with hybrid (proximal hooks and distal pedicle screws) constructs in adolescent idiopathic scoliosis (AIS) treated at a single institution., Summary of Background Data: Despite the reports of satisfactory correction and maintenance of scoliotic curves by pedicle screw instrumentation, there have been no reports on the comprehensive comparison of AIS treatment after segmental pedicle screw instrumentation versus hybrid instrumentation., Materials and Methods: A total of 58 AIS patients that underwent posterior fusion with hybrid instrumentation (29) or pedicle screw (29) instrumentation at a single institution were sorted and matched according to four criteria: similar patient age, fusion levels, identical Lenke curve type, and identical operative methods. Patients were compared at 2-year follow-up according to radiographic changes, operative time, intraoperative blood loss, pulmonary function tests, and SRS-24 outcome scores., Results: The two cohorts were well matched. The preoperative major Cobb angle averaged 62 degrees in the screw group and 60 degrees in the hybrid group. Average major curve correction was 70% in the screw group and 56% in the hybrid group (P = 0.001). At 2-year follow-up, major curve correction was 65% and 46%, respectively (P < 0.001). At 2-year follow-up, thoracic sagittal Cobb angle changes between T5 and T12 were 9.0 degrees decrease in the screw group and 2.4 degrees decrease in the hybrid group compared with preoperative (P = 0.024). There were no differences in the lowest instrumented vertebra below the lower end vertebra (P = 0.56), operative time (P = 0.14), and average estimated blood loss (P = 0.54). Two years following surgery, the screw group demonstrated improved percent predicted pulmonary function values compared with that of the hybrid group (FVC; 81% --> 81% in screw group vs. 85% --> 79% in hybrid group P = 0.08, FEV1; 73% --> 79% in screw group vs. 79% --> 75% in hybrid group, P = 0.006). Postoperative total SRS-24 scores were similar in both groups (hybrid group: 99 vs. screw group: 95) (P = 0.19). There were no neurologic complications related to hybrid or pedicle screw instrumentation., Conclusion: Pedicle screw instrumentation offers a significantly better major curve correction and postoperative pulmonary function values without neurologic problems compared with hybrid constructs. Both instrumentation methods offer similar junctional change, lowest instrumented vertebra, operative time, and postoperative SRS-24 outcome scores in the operative treatment of AIS.

Study Design: A retrospective study., Objective: To develop an accurate and reliable method to detect malpositioned pedicle screws during thoracic and lumbar spinal deformity operations using intraoperative plain radiographs., Summary of Background Data: The reliability of pedicle screw assessment using plain radiographs is more difficult during scoliosis operations compared to nondeformed spine operations. Methodology is necessary to document and improve the accuracy of interpretation of intraoperative plain radiographs for deformity surgeries., Methods: A total of 789 pedicle screws, including 632 thoracic and 157 lumbar, inserted from T1 to L4 in 49 patients with spinal deformity with postoperative computerized tomography (CT) data were investigated. According to the diagnoses, the number of screws placed was 683 for scoliosis in 43 patients and 106 for kyphosis in 6 patients. The position of the pedicle screw inserted was graded with CT as an acceptable screw (n = 724) versus violated screw (n = 65), defined as the central axis of the inserted pedicle screw out of the outer cortex of the pedicle wall. There were 3 plain radiographic criteria used to judge the accuracy of screw position after minor screw tip position adjustment according to the relative length of the screws in the lateral radiograph: (1) violation of the harmonious segmental change of the tips of the inserted screws with reference to vertebral rotation using the posterior upper spinolaminar junction in the posteroanterior (PA) radiograph (medial or lateral out); (2) no crossing of the medial pedicle wall by the tip of the pedicle screw inserted with reference to the vertebral rotation using the posterior upper spinolaminar junction in the PA radiograph (lateral out); and (3) violation of the imaginary midline of the vertebral body using the posterior upper spinolaminar junction in the PA radiograph by the position of the tip of the inserted pedicle screw (medial out)., Results: Comparative analysis of these pedicle screws using postoperative CT and intraoperative plain radiographs confirmed 65 violated pedicle screws, including 15 medial violations and 50 lateral violations. Of 15 pedicle screws with medial wall violation, 13 showed a loss of harmonious segmental change in the screw tips and violation of the imaginary midline of the vertebral body (sensitivity 0.87, specificity 0.97, and accuracy 0.98). One case showed only a loss of harmonious change in the screw tip, and the other one case did not show any significant plain radiograph findings. Of the 50 pedicle screws with lateral wall violation, 47 cases showed a loss of harmonious segmental change in the screw tips and no crossing of medial pedicle wall by the pedicle screw inserted (sensitivity 0.94, specificity 0.90, and accuracy 0.96). Two cases did not show any significant plain radiograph findings, and the other one case showed only violation of the harmonious segmental change in the screw tips., Conclusions: Intraoperative plain radiographs alone using 3 radiographic criteria were very sensitive to detect lateral wall pedicle screw violations, specific for assessing for medial wall violations, and highly accurate for both. This result confirms the ability of careful intraoperative plain radiographic assessment after pedicle screw insertion to detect malpositioned screws, to allow for possible revision during the index operation.