Showing papers on "Cobb angle published in 2010"
TL;DR: Radiographic outcomes such as the Cobb angle and AVT were significantly improved in patients who underwent a combined transpsoas and posterior approach, and the combination of XLIF and TLIF/posterior segmental instrumentation techniques may lead to less blood loss and to radiographic outcomes that are comparable to traditional posterior-only approaches.
Abstract: Object The authors recently used a combined approach of minimally invasive transpsoas extreme lateral interbody fusion (XLIF) and open posterior segmental pedicle screw instrumentation with transforaminal lumbar interbody fusion (TLIF) for the correction of coronal deformity. The complications and radiographic outcomes were compared with a posterior-only approach for scoliosis correction. Methods The authors retrospectively reviewed all deformity cases that were surgically corrected at the University of Pittsburgh Medical Center Presbyterian Hospital between June 2007 and August 2009. Eight patients underwent combined transpsoas and posterior approaches for adult degenerative thoracolumbar scoliosis. The comparison group consisted of 4 adult patients who underwent a posterior-only scoliosis correction. Data on intra- and postoperative complications were collected. The pre- and postoperative posterior-anterior and lateral scoliosis series radiographic films were reviewed, and comparisons were made for coro...
245 citations
TL;DR: In idiopathic scoliosis, progression is most likely during periods of rapid growth, and the optimal follow-up interval in skeletally immature patients may be as short as 4 months, so only curves of more than 30° must be monitored for progression.
Abstract: Scoliosis is defined as a lateral spinal curvature with a Cobb angle of 10° or more. This abnormal curvature may be the result of an underlying congenital or developmental osseous or neurologic abnormality, but in most cases the cause is unknown. Imaging modalities such as radiography, computed tomography (CT), and magnetic resonance (MR) imaging play pivotal roles in the diagnosis, monitoring, and management of scoliosis, with radiography having the primary role and with MR imaging or CT indicated when the presence of an underlying osseous or neurologic cause is suspected. In interpreting the imaging features of scoliosis, it is essential to identify the significance of vertebrae in or near the curved segment (apex, end vertebra, neutral vertebra, stable vertebra), the curve type (primary or secondary, structural or nonstructural), the degree of angulation (measured with the Cobb method), the degree of vertebral rotation (measured with the Nash-Moe method), and the longitudinal extent of spinal involvement (according to the Lenke system). The treatment of idiopathic scoliosis is governed by the severity of the initial curvature and the probability of progression. When planning treatment or follow-up imaging, the biomechanics of curve progression must be considered: In idiopathic scoliosis, progression is most likely during periods of rapid growth, and the optimal follow-up interval in skeletally immature patients may be as short as 4 months. After skeletal maturity is attained, only curves of more than 30° must be monitored for progression.
183 citations
TL;DR: A minimal though significant change in activity was observed in patients with adolescent idiopathic scoliosis undergoing surgical correction of their spinal deformity, such that the calculated MCID was within the measurement error.
Abstract: Study design Longitudinal cohort. Objective To determine the minimum clinically important difference (MCID) of the Scoliosis Research Society (SRS)-22 Appearance, Activity, and Pain domains in patients with adolescent idiopathic scoliosis undergoing surgical correction of their spinal deformity. Summary of background data The MCID, a threshold of improvement that is clinically relevant to the individual patient, is increasingly used to evaluate treatment effectiveness. MCID values for the SRS-22 domains have not been determined. Methods Patients with adolescent idiopathic scoliosis who underwent surgical correction and had completed SRS-22 before operation and the SRS-30 and Scoliosis Appearance Questionnaire (SAQ) at 1 year after operation from a multicenter database for pediatric scoliosis were identified. The SAQ is a modification of the Walter Reed Visual Assessment Scale and is used to assess the patient's perception of their spinal deformity. Paired sample t tests were used to compare preoperative and 1-year postoperative scores. Spearman correlations were used to evaluate associations between domain scores and summed responses to anchors for Appearance, Activity, and Pain. MCID values for the SRS-22 domains were determined using receiver operating characteristic curve analysis, with summed responses to anchor questions 23 to 30 of the SRS-30 and items 26 and 32 of the SAQ. Results There were 735 women and 152 men with a mean age of 14.3 years and a mean Cobb angle of 53°. There was a statistically significant difference between paired preoperative and 1-year SRS domain scores. Analysis of variance showed a statistically significant difference between the summed responses to the anchors. The MCID was 0.20 for the Pain domain (area under the curve [AUC] = 0.723), 0.08 for Activity (AUC = 0.648), and 0.98 for Appearance (AUC = 0.629). The MCID for activity was less than the standard error of measurement. Conclusion The MCID for the Pain domain was 0.20 and 0.98 for Appearance. Because these patients were generally in good health, a minimal though significant change in activity was observed, such that the calculated MCID was within the measurement error. As expected, the largest and most important change was in the Appearance domain. Future studies are needed to determine the MCID for the mental domain and the total SRS score and to further validate the MCID values in this study.
172 citations
TL;DR: The complication rate in growing spine surgery is uniformly high but varies by implant type, with a trend toward fewer complications in hybrid constructs.
Abstract: Study design Retrospective review. Objective To evaluate the complication rate of various types of growing spinal implants. Summary of background data Previous studies report a complication rate of 0.38 to 1.19 per patient in growing spine surgery, but this may be an underestimate. Methods Medical records of 36 children with early-onset spinal deformity treated with various types of growing implants by a single surgeon were evaluated for complications. Patients with primary chest wall deformities were excluded. Complications were defined as any neurologic injuries, and any unplanned surgeries for implant failure or infection. Patients were separated into 3 groups: (A) standard dual growing rods, (B) hybrid growing rods with rib anchors proximally and spine anchors distally, and (C) VEPTR (vertical expandable prosthetic titanium rib). Statistical analyses were performed to compare the complication rate among the 3 groups and to evaluate the effect of Cobb angle, kyphosis, age, and body mass index on the complication rate. Results Mean age at initial implantation was 4.8 years; mean follow-up was 51 months (24-117 months). A total of 72 unplanned surgeries occurred in 26 out of 36 patients (72%), including 18 revisions for rod breakage, 31 revisions for migrated anchors, and 18 irrigations and debridements for infection. Two children (5.6%) developed a neurologic deficit that required implant removal. Group A had 23 complications in 10 patients, with a complication rate of 2.3 per patient; group B had 6 complications in 7 patients, with a rate of 0.86 per patient; and group C had 45 complications in 19 patients, with a rate of 2.37 per patient. There was no significant difference between the 3 groups in terms of preoperative Cobb angle, kyphosis, age, and body mass index; these factors did not seem to influence the complication rate. Conclusion To our knowledge, this is the first study directly comparing the complication rates of various types of growing spine implants. The complication rate in growing spine surgery is uniformly high but varies by implant type, with a trend toward fewer complications in hybrid constructs.
169 citations
TL;DR: Between the 2-year and the 3- to 5-year points surgically treated adult spinal deformity patients will show significant reduction in outcomes by Scoliosis Research Society (SRS), Oswestry Disability Index (ODI), and numerical rating scale back and leg pain scores and will show increasing thoracic kyphosis, loss of lumbar lordosis, and loss of coronal and sagittal balance.
Abstract: Study design Retrospective analysis of data entered prospectively into a multicenter database-clinical and radiographic outcomes assessment. Objective Our hypothesis is that between the 2-year and the 3- to 5-year points surgically treated adult spinal deformity patients will show significant reduction in outcomes by Scoliosis Research Society (SRS), Oswestry Disability Index (ODI), and numerical rating scale back and leg pain scores and will show increasing thoracic kyphosis, loss of lumbar lordosis, and loss of coronal and sagittal balance. Summary of background data Most analyses of primary presentation adult spinal deformity surgery assess 2-year follow-up. However, it is established that in some patients unfavorable events occur between the 2-year and 5-year points. Methods The cohort of 113 patients entered into a multicenter database with complete preoperative, 2-year, and 3- to 5-year data. All patients who had adult spinal deformity and surgical treatment represented their first reconstruction. Diagnoses were scoliosis (82.5%), kyphosis (10%), and scoliosis and kyphosis combined (7.5%). Outcome measures and basic radiographic parameters (curve size, thoracic and lumbar sagittal plane, coronal and sagittal balance) were assessed at those 3 time intervals. Complications (pseudarthrosis/implant failure, infection, and junctional deformities) were assessed at the 2-year and the 3- to 5-year (mean, 3.76 years) points. RESULTS.: The mean major curve Cobb angle (preoperative, 57°; 2-year, 29°; 3-5 year, 26°); thoracic kyphosis T5 to T12 (30°, 31°, 32°) and lumbar lordosis T12 to sacrum (48°, 49°, 51°) did not change from the 2-year to ultimate follow-up. Likewise, coronal and sagittal balance parameters were the same at 2-year and ultimate follow-up. SRS total scores and modified ODI were similar at the 2 year and final follow-up (SRS: 3.89-3.88; ODI: 19-18). Preoperative SRS total score was 3.17. Six patients demonstrated complications at the 2-year point and additional 9 patients demonstrated complications at the 3- to 5-year point. Those 9 patients with complications at ultimate follow-up demonstrated significant deterioration in their ODI and SRS scores when compared with the patients who did not have complications at ultimate follow-up. Conclusion Contrary to our hypothesis, we could not establish deterioration in mean radiographic or clinical outcomes between the 2-year and 3- to 5-year follow-up points when analyzing the group as a whole. However, for the 9 patients who experienced complications between 3- and 5-year follow-up, their outcomes were significantly worse than for the other 104 patients.One should not anticipate an overall radiographic and clinical deterioration of the outcomes of surgically treated primary presentation adult spinal deformity patients in this studied time interval. However, close to 10% of patients will experience a new complication at the 3- to 5-year point, most commonly implant failure/nonunion and/or junctional kyphosis, which will negatively effect the patient-reported outcome.
156 citations
TL;DR: The rate of autofusion in children treated with growing rods was 89%.
Abstract: Study design Retrospective case review of skeletally immature patients treated with growing rods. Patients received an average of 9.6 years follow-up care. Objective (1) to identify the rate of autofusion in the growing spine with the use of growing rods; (2) to quantify how much correction can be attained with definitive instrumented fusion after long-term treatment with growing rods; and (3) to describe the extent of Smith-Petersen osteotomies required to gain correction of an autofused spine following growing rod treatment. Summary of background data The safety and use of growing rods for curve correction and maintenance in the growing spine population has been established in published reports. While autofusion has been reported, the prevalence and sequelae are not known. Methods Nine skeletally immature children with scoliosis were identified who had been treated using growing rods. A retrospective review of the medical records and radiographs was conducted and the following data collected: complications, pre- and postoperative Cobb angles at time of initial surgery (growing rod placement), pre- and postoperative Cobb angles at time of final surgery (growing rod removal and definitive fusion), total spine length as measured from T1-S1, % correction since initiation of treatment and at definitive fusion, total number of surgeries, and number of patients found to have autofusion at the time of device removal. Results The rate of autofusion in children treated with growing rods was 89%. The average percent of the Cobb angle correction obtained at definitive fusion was 44%. On average, 7 osteotomies per patient were required at the time of definitive fusion due to autofusion. Conclusion Although growing rods have efficacy in the control of deformity within the growing spine, they also have adverse effects on the spine. Immature spines treated with a growing rod have high rates of unintended autofusion which can possibly lead to difficult and only moderate correction at the time of definitive fusion.
154 citations
TL;DR: There is a high incidence of postoperative proximal junctional kyphosis after posterior fusion to the upper thoracic vertebra within 1.5 years after surgery in adolescents with idiopathic scoliosis, and the risk factors for PJK should be carefully evaluated before surgery.
Abstract: Study design A retrospective analysis of 150 adolescents who underwent spinal fusion for idiopathic scoliosis. Objective To analyse the incidence of the postoperative proximal junctional kyphosis after posterior fusion to the upper thoracic vertebra in adolescents with idiopathic scoliosis and to explore its risk factors. Summary of background data The reported incidence of the proximal junctional kyphosis after the posterior fusion in patients with idiopathic scoliosis varies depending on surgical methods and strategies adopted by the institution. Methods The changes in the Cobb angle of the proximal junctional kyphosis on the lateral spine X-ray were measured and the presence of PJK was recorded. The risk factors were screened using statistical analysis. Results PJK occurred in 35 out of 123 patients with an overall incidence of 28%. Among them, 28 patients (80%) experienced PJK within 1.5 years after surgery. The PJK-inducing factors included greater than 10° intraoperative decrease in thoracic kyphosis, thoracoplasty, the use of a pedicle screw at the top vertebra, autogenous bone graft and fusion to the lower lumbar vertebra (below L2). Conclusions There is a high incidence of postoperative proximal junctional kyphosis after posterior fusion to the upper thoracic vertebra within 1.5 years after surgery in adolescents with idiopathic scoliosis. In order to reduce its incidence, the risk factors for PJK should be carefully evaluated before surgery.
123 citations
TL;DR: This is the largest study that has demonstrated that school scoliosis screening in Hong Kong is predictive and sensitive with a low referral rate and should thus be continued in order to facilitate early administration of conservative treatments.
Abstract: STUDY DESIGN Retrospective cohort study. OBJECTIVE To evaluate the clinical effectiveness of school scoliosis screening using a large and long-term-followed cohort of students in Hong Kong. SUMMARY OF BACKGROUND DATA School screening for adolescent idiopathic scoliosis has been criticized as resulting in over-referrals for radiography and having low predictive values. Indeed, all but one previous retrospective cohort studies had no follow-up assessments of students until their skeletal maturity, leaving any late-developed curves undetected. The one study that completed this follow-up was well conducted but had low precisions due to its small sample size. METHODS A total of 157,444 students were eligible for a biennial scoliosis screening, and their screening results and medical records up to 19 years of age were available. Students first had forward bending test and angle of trunk rotation (ATR) performed. Those with ATR between 5 degrees and 14 degrees or signs of adolescent idiopathic scoliosis were assessed by moire topography regularly. Students with an ATR >or=15 degrees , >or=2 moire lines, or significant clinical signs were referred for radiography and had their Cobb angle measured. RESULTS Of the 115,190 screened students in the cohort, 3228 (2.8%, 95% confidence interval [CI] = 2.7%-2.9%) were referred for radiography. At the final follow-up, the positive predictive values were 43.6% (41.8%-45.3%) for a Cobb angle >or=20 degrees and 9.4% (8.4%-10.5%) for needing treatment, while the sensitivities were 88.1% (86.4%-89.6%) and 80.0% (75.6%-83.9%), respectively. CONCLUSION This is the largest study that has demonstrated that school scoliosis screening in Hong Kong is predictive and sensitive with a low referral rate. Screening should thus be continued in order to facilitate early administration of conservative treatments.
123 citations
TL;DR: Pedicle screw constructs provided excellent coronal and sagittal correction of main thoracic adolescent idiopathic scoliosis, however, this was at the expense of sagittal contour.
Abstract: STUDY DESIGN: Single institution, retrospective cohort study of 49 consecutive patients with Lenke I adolescent idiopathic scoliosis, all operated by a single surgeon using identical surgical technique and type of instrumentation. OBJECTIVE: To evaluate the early coronal and sagittal correction of main thoracic adolescent idiopathic scoliosis using all-pedicle screw instrumentation and to determine whether implant density influences correction. SUMMARY OF BACKGROUND DATA: There is an increasing trend in the use of pedicle screws in scoliosis correction surgery, particularly in using segmental all-pedicle screw constructs. No previous studies have investigated whether higher pedicle screw implant density improves correction of scoliosis in vivo. METHODS: Forty-nine consecutive patients with Lenke I main thoracic adolescent idiopathic scoliosis underwent single stage posterior correction and instrumented spinal fusion with pedicle screw fixation between 2006 and 2008. Pre- and postoperative radiographs were analyzed. Mean patient age at the time of operation was 14.4 years (range: 11-19.7 years). RESULTS: The preoperative main thoracic curve of 60.0 degrees +/- 13.4 degrees was corrected to 17.4 degrees +/- 6.9 degrees (69.9% correction) on the postoperative radiographs. The preoperative thoracic kyphosis of 20.0 degrees +/- 10.2 degrees decreased to 11.6 degrees +/- 4.9 degrees after surgery. There was a significant correlation between decrease in sagittal kyphosis and magnitude of coronal Cobb angle correction (P = 0.002). There was no correlation between implant density and magnitude of coronal or sagittal curve correction, with and without curve flexibility taken into consideration. CONCLUSION: Pedicle screw constructs provided excellent coronal correction of thoracic idiopathic scoliosis, however, this was at the expense of sagittal contour. Bilateral segmental pedicle screw fixation did not improve curve correction compared with unilateral or alternate segmental fixation.
123 citations
TL;DR: Originally designed for thoracic insufficiency syndromes related to rib and vertebral anomalies, VEPTR proved to be a valuable alternative to dual growing rods for non-congenital early onset spine deformities and might provoke less spontaneous spinal fusion and ease the final correction at maturity.
Abstract: This retrospective study analyses 23 children treated with vertical expandable prosthetic titanium rib (VEPTR) for correction of non-congenital early onset spine deformities. After the index procedure (IP), the device was lengthened at 6-month intervals. The average (av) age at the time of IP was 6.5 years (1.11-10.5). The av follow-up time was 3.6 years (2-5.8). Diagnosis included 1 early onset idiopathic scoliosis, 11 neuromuscular, 2 post-thoracotomy scoliosis, 1 Sprengel deformity, 2 hyperkyphosis, 1 myopathy and 5 syndromic. Surgeries (187) included 23 IPs, av 6.5 (4-10) device expansions per patient (149) and 15 unplanned surgeries. 23 complications (0.13 per surgery) included 10 skin sloughs, 5 implant dislocations, 2 rod breakages and 6 infections. Coronal Cobb angle was av 68 degrees (11 degrees -111 degrees ), at follow-up av 54 degrees (0 degrees -105 degrees). Pelvic obliquity was av 33 degrees (13 degrees -60 degrees ), at follow-up av 16 degrees (0 degrees -42 degrees ). T1 tilt was av 29 degrees (5 degrees -84 degrees ), two remained unchanged, the remainder improved 10 degrees -68 degrees. Sagittal plane: All but two had stable profiles, two hyperkyphosis of 110 degrees /124 degrees improved to 56 degrees /86 degrees. Space available for lung ratio was less than 90% in ten before the IP, improved in nine and deteriorated in one. Originally designed for thoracic insufficiency syndromes related to rib and vertebral anomalies, VEPTR proved to be a valuable alternative to dual growing rods for non-congenital early onset spine deformities. The complication rate was lower, the control of the sagittal plane and the pelvic obliquity was as good, but the correction of the coronal plane deformity was less than growing rods. However, VEPTR's spine-sparing approach might provoke less spontaneous spinal fusion and ease the final correction at maturity.
105 citations
TL;DR: The results showed that Cobb angle measurements may be reproduced in the computer as reliably as with the traditional manual method, in similar conditions to those found in clinical practice.
TL;DR: Multilevel registration may decrease operative time without compromising accuracy of pedicle screw placement afforded by this technique in the setting of adolescent idiopathic scoliosis.
Abstract: Study design Retrospective clinical study. Objective To assess the accuracy of multilevel registration for skip pedicle screw placement during image-guided, computer-assisted spine surgery, in the setting of adolescent idiopathic scoliosis (AIS). Summary of background data Computerized frameless stereotactic image-guidance has been used recently to improve pedicle screw placement accurately and safety during spine surgery. Because of possible intervertebral motion and usual difference in patients' position between preoperative imaging and surgery, the imaging model and the surgically exposed spine may be significantly discordant. Consequently, current protocols suggested separate registration of each spinal level (single-level registration) before respective pedicle screw placement, a time-consuming process. Moreover, although multilevel registration for lumbar spine has been reported, and that for thoracic spine has not. Methods A total of 19 patients (1 male and 18 females; mean age, 13.9 years) with AIS who underwent multilevel registration for skip pedicle screw placement were included. Variables including surgical time, blood loss, preoperative and 2-year postoperative Cobb angle, correction rate, and postoperative screw position by computed tomography image were evaluated. Mean registration error after point merge and again after surface merge were recorded for each consecutive vertebra of each case. Results Mean surgical time was 310 minutes (range, 168-420 min). Mean blood loss 1138 g (range, 300-2300 g). Cobb angle before operation and at 2 years postoperation was 62.4 degrees (43 degrees-100 degrees) and 21.6 degrees (9 degrees-42 degrees), respectively. Mean correction rate 66.2% (39.7%-84.5%). Total 265 screws were inserted with computed tomography-based navigation system. Pedicle violation was observed in only 4 screws (1.5%). No neurovascular complication occurred. After point merge, average Mean registration error of all cases was 1.69 +/- 0.52 mm, and after surface merge was 0.51 +/- 0.16 mm. Conclusion Multilevel registration may decrease operative time without compromising accuracy of pedicle screw placement afforded by this technique in the setting of AIS.
TL;DR: Dynamic stabilization with pedicle screws in addition to decompressive laminectomy resulted a safe procedure in elderly patients with degenerative lumbar scoliosis; it was able to maintain enough stability to prevent progression of scoliotic instability and instability.
Abstract: Study design A retrospective study. Objective To analyze outcomes after dynamic stabilization without fusion in degenerative lumbar scoliosis in elderly patients. Summary of background data Frequent complications of posterolateral instrumented fusion have been reported after treatment of degenerative lumbar scoliosis in elderly patients. The use of dynamic stabilization without fusion can be advocated to reduce such adverse effects, being less invasive, with shorter operation time and less blood loss. No study in the literature has analyzed outcomes of dynamic stabilization without fusion in these degenerative deformities. Methods Twenty-nine elderly patients (average age, 68.5 years; range, 61-78) with degenerative lumbar scoliosis, undergoing dynamic stabilization (Dynesys system) without fusion combined with decompressive laminectomy, in cases with associated stenosis, were analyzed. Stenosis of the vertebral canal was associated in 27 patients (93.1%); 13 cases (44.8%) also presented a degenerative spondylolisthesis. An independent spine surgeon retrospectively reviewed all the patients' medical records and radiographs to assess operative data and surgery-related complications. Preoperative, postoperative, and follow-up questionnaires were obtained to evaluate clinical outcomes. Results The mean follow-up time was 54 months (range, 39-68). Oswestry Disability Index, Roland Morris Disability Questionnaire, and back pain and leg pain visual analogue scale scores received a statistically significant improvement at last control; the mean improvement was 51.6% for Oswestry Disability Index (P = 0.01), 58.2% for Roland Morris Disability Questionnaire (P = 0.01), 51.7% for leg pain (P = 0.02), and 57.8% for back pain (P = 0.01). Radiographically, degenerative scoliosis and associated spondylolisthesis resulted stable at follow-up with a moderate correction: the average scoliosis Cobb angle was 16.9 degrees (range, 12 degrees -37 degrees) before surgery and 11.1 degrees (range, 4 degrees -26 degrees) at last follow-up, with a 37.5% mean correction (P = 0.01); the anterior vertebral translation was 18.9% (range, 12%-27%) before surgery and 17% (range, 0%-27%) at follow-up, for a 14.6% mean correction (range, 0%-100%) (P = 0.02). No implant-related complications (screw loosening or breakage) or loss of correction were observed. Four cases (13.8%) presented an asymptomatic radiolucent line around screws of the S1 level without screw loosening. Six patients (20.7%) showed minor complications (ileus in 2 cases, urinary tract infection in 2, transient postoperative delirium in one, and respiratory difficulties after surgery in another patient). In 2 other patients (6.8%) incurred major complications, both requiring a revision surgery, for a misplaced screw on L5 and junctional disc degeneration at the lower level respectively. No neurologic complications occurred. Conclusion Dynamic stabilization with pedicle screws in addition to decompressive laminectomy resulted a safe procedure in elderly patients with degenerative lumbar scoliosis; it was able to maintain enough stability to prevent progression of scoliosis and instability, enabling a wide laminectomy in cases of associated lumbar stenosis. This nonfusion stabilization technique was less aggressive than instrumented fusion and obtained a statistically significant improvement of the clinical outcome at last follow-up.
TL;DR: The results suggest that race may influence an individual's natural spinopelvic alignment, and serves as a reminder when planning surgical reconstruction for spinal deformity.
Abstract: Study design A retrospective review of clinical and radiographic data from a multicenter adolescent idiopathic scoliosis (AIS) database. OBJECTIVE.: The purpose of this study was to perform a comprehensive radiographic evaluation of the differences in pelvic parameters between 2 groups (white and black) in a scoliotic population. Summary of background data Increasingly, the importance of spinopelvic alignment and balance is appreciated as a major factor in the energy-efficient posture of the individual in the normal and diseased states. Pelvic incidence (PI) determines the lordosis of the patient and equations defining the interplay of pelvic parameters, lordosis, and kyphosis have been developed to guide surgical decision-making for spinal deformity. PI and thoracic lordosis have been previously shown to be increased in the AIS population. Methods Data were obtained from a prospective multicenter AIS database from a total of 1658 patients. We evaluated the 2 largest racial subsets in our database. We identified 421 whites and 115 black patients who met inclusion criteria. The parameters evaluated on preoperative full-length coronal and lateral radiographs were PI, sacral slope (SS), pelvic tilt, lumbar lordosis (LL), thoracic kyphosis, sagittal Cobb angle, and the shift of the sagittal C7 plumb line. Results Age, gender, major and minor cobb angles were similar in the 2 groups. PI, pelvic tilt, and LL were found to be significantly greater in the black group when compared with the white group (black: 56.0, 13.9, and -63.6 vs. white: 52.5, 10.8, and -59.1). Conclusion In our study, significant differences were found in 3 of the 6 sagittal plane parameters between the 2 groups. With a larger PI, a larger LL is required in order maintain a neutral sagittal balance. Our results suggest that race may influence an individual's natural spinopelvic alignment, and serves as a reminder when planning surgical reconstruction for spinal deformity.
TL;DR: The use of computer-designed polystyrene models could provide more accurate morphometric information and facilitate surgical correction of complex severe spinal deformity.
Abstract: Surgical treatment of complex severe spinal deformity, involving a scoliosis Cobb angle of more than 90° and kyphosis or vertebral and rib deformity, is challenging. Preoperative two-dimensional images resulting from plain film radiography, computed tomography (CT) and magnetic resonance imaging provide limited morphometric information. Although the three-dimensional (3D) reconstruction CT with special software can view the stereo and rotate the spinal image on the screen, it cannot show the full-scale spine and cannot directly be used on the operation table. This study was conducted to investigate the application of computer-designed polystyrene models in the treatment of complex severe spinal deformity. The study involved 16 cases of complex severe spinal deformity treated in our hospital between 1 May 2004 and 31 December 2007; the mean ± SD preoperative scoliosis Cobb angle was 118° ± 27°. The CT scanning digital imaging and communication in medicine (DICOM) data sets of the affected spinal segments were collected for 3D digital reconstruction and rapid prototyping to prepare computer-designed polystyrene models, which were applied in the treatment of these cases. The computer-designed polystyrene models allowed 3D observation and measurement of the deformities directly, which helped the surgeon to perform morphological assessment and communicate with the patient and colleagues. Furthermore, the models also guided the choice and placement of pedicle screws. Moreover, the models were used to aid in virtual surgery and guide the actual surgical procedure. The mean ± SD postoperative scoliosis Cobb angle was 42° ± 32°, and no serious complications such as spinal cord or major vascular injury occurred. The use of computer-designed polystyrene models could provide more accurate morphometric information and facilitate surgical correction of complex severe spinal deformity.
TL;DR: It is concluded that although flaccid neuromuscular scoliosis can be well corrected with posterior-only pedicle screw, there is a high rate of associated complications.
Abstract: Literature has described treatment of flaccid neuromuscular scoliosis using different instrumentation; however, only one article has been published using posterior-only pedicle screw fixation. Complications using pedicle screws in paralytic neuromuscular scoliosis has not been described before. To present results and complications with posterior-only pedicle screws, a retrospective study was carried out in 27 consecutive patients with flaccid neuromuscular scoliosis (Duchenne muscular dystrophy and spinal muscular atrophy), who were operated between 2002 and 2006 using posterior-only pedicle screw instrumentation. Immediate postoperative and final follow-up results were compared using t test for Cobb angle, pelvic obliquity, thoracic kyphosis and lumbar lordosis. Perioperative and postoperative complications were noted from the hospital records of each patient. Complications, not described in literature, were discussed in detail. Average follow-up was 32.2 months. Preoperative, immediate postoperative and final follow-up Cobb angle were 79.8°, 30.2° (63.3% correction, p < 0.0001) and 31.9°, respectively; and pelvic obliquity was 18.3°, 8.9° (52% correction, p < 0.0001) and 8.9°. Postoperative thoracic kyphosis remained unchanged from 27.6° to 19.9° (p = 0.376); while lumbar lordosis improved significantly from +15.6° to −22.4° lordosis (p = 0.0002). Most patients had major to moderate improvement in postoperative functional and ambulatory status compared to the preoperative status. Thirteen (48.1%) perioperative complications were noted with five major complications (four respiratory in the form of hemothorax or respiratory failure that required ventilator support and one death) and eight minor complications (three UTI, two atelectasis, two neurological and one ileus). Postoperatively, we noted complications, such as coccygodynia with subluxation in 7, back sore on the convex side in 4 and dislodging of rod distally in 1 patient making a total of 12 (44.4%) postoperative complications. Of 12 postoperative complications, 6 (50%) required secondary procedure. We conclude that although flaccid neuromuscular scoliosis can be well corrected with posterior-only pedicle screw, there is a high rate of associated complications.
TL;DR: This tool will facilitate clinical practice by monitoring trunk posture among persons with IS and may contribute to a reduction in the use of radiographs to monitor scoliosis progression.
Abstract: STUDY DESIGN Concurrent validity between postural indices obtained from digital photographs (two-dimensional [2D]), surface topography imaging (three-dimensional [3D]), and radiographs. OBJECTIVE To assess the validity of a quantitative clinical postural assessment tool of the trunk based on photographs (2D) as compared to a surface topography system (3D) as well as indices calculated from radiographs. SUMMARY OF BACKGROUND DATA To monitor progression of scoliosis or change in posture over time in young persons with idiopathic scoliosis (IS), noninvasive and nonionizing methods are recommended. In a clinical setting, posture can be quite easily assessed by calculating key postural indices from photographs. METHODS Quantitative postural indices of 70 subjects aged 10 to 20 years old with IS (Cobb angle, 15 degrees -60 degrees) were measured from photographs and from 3D trunk surface images taken in the standing position. Shoulder, scapula, trunk list, pelvis, scoliosis, and waist angles indices were calculated with specially designed software. Frontal and sagittal Cobb angles and trunk list were also calculated on radiographs. The Pearson correlation coefficients (r) was used to estimate concurrent validity of the 2D clinical postural tool of the trunk with indices extracted from the 3D system and with those obtained from radiographs. RESULTS The correlation between 2D and 3D indices was good to excellent for shoulder, pelvis, trunk list, and thoracic scoliosis (0.81>r r<0.56; P<0.05). The correlation between 2D and radiograph spinal indices was fair to good (-0.33 to -0.80 with Cobb angles and 0.76 for trunk list; P<0.05). CONCLUSION This tool will facilitate clinical practice by monitoring trunk posture among persons with IS. Further, it may contribute to a reduction in the use of radiographs to monitor scoliosis progression.
TL;DR: Favorable outcomes have been demonstrated in this large single-center series of growing-rod constructs used to treat scoliosis in the growing spine and their safety and efficacy in controlling spinal deformity and allowing spinal growth along with an acceptable rate of complications would support the continued use of single growing-Rod constructs as a scolia management option.
Abstract: Study Design. Retrospective clinical and radiologic review of consecutive series of patients treated with single submuscular growing rods from a single center with a minimum of 2-year follow-up. Objectives. To describe the surgical technique and methods used to minimize complications and to report on the outcomes of a large consecutive series of patients treated with single submuscular growing rods for scoliosis in the immature spine from a single center. Summary of Background Data. Previous studies have reported on the safety and efficacy of single and dual growing-rod constructs; however, these studies have been of small patient numbers with varying results. Methods. Between 1999 and 2007, 88 patients underwent the insertion of a single, submuscular growing-rod construct for scoliosis. A clinical and radiologic review of these 88 consecutive patients with a minimum of 2-year follow-up was conducted. Diagnoses include idiopathic, neuromuscular, syndromic, and congenital. Data include Cobb angle measurements, T1-S1 heights, number, and frequency of lengthening as well as complications. Results. The patients underwent single submuscular growing-rod insertion at an average age of 7.0 years. The mean follow-up period was 42 months. Twenty-eight patients had a simultaneous apical fusion. Growing-rod lengthening was performed on an average at 9-month intervals. The average initial Cobb angle was 73° (range: 40-117) and improved to 44° (range: 9-90) at final follow-up. T1-S1 height gain was 3.37 cm; this translates to 1.04 cm growth/yr. No significant difference was noted between those who had undergone apical fusion and those without. Complications noted in this series include 8 incidences of superficial infection and 3 of deep infection, proximal junctional kyphosis in 2 patients requiring early fusion, 31 rod fractures, 10 cases of proximal anchor failure, and 6 distal anchor failures. Thirty patients within study group have reached definitive fusion. Conclusion. Favorable outcomes have been demonstrated in this large single-center series of growing-rod constructs used to treat scoliosis in the growing spine. Their safety and efficacy in controlling spinal deformity and allowing spinal growth along with an acceptable rate of complications would support the continued use of single growing-rod constructs as a scoliosis management option.
TL;DR: There was a significant difference in the epidemiological distribution and prevalence between the age and gender groups, and the older adults showed a larger prevalence and more severe scoliosis, more prominent in women.
Abstract: In order to determine the epidemiology of adult scoliosis in the elderly and to analyse the radiological parameters and symptoms related to adult scoliosis, we carried out a prospective cross-sectional radiological study on 1347 adult volunteers. There were 615 men and 732 women with a mean age of 73.3 years (60 to 94), and a mean Cobb angle of 7.55 degrees (sd 5.95). In our study, 478 subjects met the definition of scoliosis (Cobb angle > or = 10 degrees ) showing a prevalence of 35.5%. There was a significant difference in the epidemiological distribution and prevalence between the age and gender groups. The older adults showed a larger prevalence and more severe scoliosis, more prominent in women (p = 0.004). Women were more affected by adult scoliosis and showed more linear correlation with age (p < 0.001). Symptoms were more severe in those with scoliosis than in the normal group, but were similar between the mild, moderate and severe scoliosis groups (p = 0.224) and between men and women (p = 0.231). Adult scoliosis showed a significant relationship with lateral listhesis, vertebral rotation, lumbar hypolordosis, sagittal imbalance and a high level of the L4-5 disc (p < 0.0001, p < 0.0001, p = 0.002, p = 0.002, p < 0.0001 respectively). Lateral listhesis, lumbar hypolordosis and sagittal imbalance were related to symptoms (p < 0.0001, p = 0.001, p < 0.0001 respectively).
TL;DR: Two common methyl-CpG-binding protein 2 (MECP2) mutations, R294X and R306C, had reduced risk for scoliosis and extended understanding of comorbidities, clinical severity, and relative risk reduction for specific mutations.
Abstract: To understand scoliosis, related comorbidities, and phenotype-genotype correlations in individuals with Rett syndrome (RTT), the Rare Disease Clinical Research Network database for RTT was probed. Clinical evaluations included a detailed history and physical examination, comprehensive anthropometric measurements, and two quantitative measures of clinical status, Clinical Severity Scale (CSS) and motor-behavioral analysis (MBA). All data were exported to the Data Technology Coordinating Center (DTCC) at the University of South Florida. Scoliosis assessment was based on direct examination and curvature measurements by radiography (Cobb angle). Statistical analyses included univariate and multiple logistic regression models, adjusting for age at enrollment or mutation type. Scoliosis data were available from 554 classic RTT participants, mean age = 10 y (0-57 y). Scoliosis was noted in 292 (53%); mean age = 15 y with scoliosis and 6 y without. Using multiple regression analysis, MBA severity score, later acquisition, loss or absent walking, and constipation were associated with scoliosis. Two common methyl-CpG-binding protein 2 (MECP2) mutations, R294X and R306C, had reduced risk for scoliosis. These findings corroborated previous reports on scoliosis and extended understanding of comorbidities, clinical severity, and relative risk reduction for specific mutations. Clinical trial design should account for scoliosis and related factors judiciously.
TL;DR: In this paper, a prospective radiographic analysis of patients with thoracic adolescent idiopathic scoliosis who were managed operatively with alternate-level pedicle screw fixation at a single institution was performed.
Abstract: Background: The fulcrum bending radiograph accurately predicts scoliosis curve correction in patients with thoracic adolescent idiopathic scoliosis who are managed with hooks. We assessed the predictive value of the fulcrum bending radiograph in the context of alternate-level pedicle screw fixation of the scoliotic spine.
Methods: A prospective radiographic analysis of patients with thoracic adolescent idiopathic scoliosis who were managed operatively with alternate-level pedicle screw fixation at a single institution was performed. The Cobb angle was measured on posteroanterior standing coronal radiographs that were made preoperatively and one week postoperatively. The fulcrum flexibility percentage and the fulcrum bending correction index percentage were calculated.
Results: Forty-two patients were assessed. The mean age at the time of surgery was 14.6 years, and the mean number of fused levels was 9.4. On the preoperative radiographs, the mean values for the standing Cobb angle, the fulcrum bending radiograph Cobb angle, and fulcrum flexibility were 57.9°, 21.8°, and 62.7%, respectively. On the one-week postoperative radiographs, the mean Cobb angle was 15.4°, the mean curve correction was 73.4%, and the mean fulcrum bending correction index was 122.1%. A significant, positive correlation was noted between the fulcrum bending radiograph angle and the fulcrum bending correction index, indicating that the fulcrum bending radiograph could predict the correction of flexible curves; however, for stiff curves, pedicle screws could provide more correction than the fulcrum bending radiograph predicted.
Conclusions: To our knowledge, this is the first study to demonstrate the predictive value of the fulcrum bending radiograph in the context of alternate-level pedicle screw fixation in patients with adolescent idiopathic scoliosis. Curve flexibility may dictate the degree of the fulcrum bending correction index, whereby a curve that is less flexible may achieve a greater fulcrum bending correction index. The fulcrum bending radiograph has potential predictive utility. In addition, pedicle screw constructs appear to have a better ability to correct scoliosis in comparison with hooks and hybrid constructs.
Level of Evidence: Prognostic Level I. See Instructions to Authors for a complete description of levels of evidence.
TL;DR: Based on a novel pedicle channel classification describing the osseous anatomy encountered during pedicle probe insertion, it was found during surgery that 90% of thoracic pedicles had a cancellous channel, whereas 7% had a cortical channel and only 3% had an absent channel.
Abstract: Study Design. Prospective clinical series. Objective. To determine how many thoracic scoliotic pedicles have cancellous versus cortical versus absent channels. Summary of Background Data. Although morphologic evaluations of thoracic pedicles have been well reported, the results do not practically reflect clinical findings during actual pedicle screw placement. We propose a novel pedicle channel classification describing the osseous anatomy encountered during pedicle probe insertion. Methods. We noted 4 pedicle types in 53 consecutive scoliosis patients. Type A: pedicle probe smoothly inserted without difficulty; the morphology is described as a "Large Cancellous Channel." Type B: pedicle probe inserted snugly with increased force; described as a "Small Cancellous Channel." Type C: pedicle probe cannot be manually pushed but must be tapped with a mallet down the pedicle into the body; described as a "Cortical Channel." Type D: pedicle probe cannot locate a channel thus necessitating a "juxtapedicular" screw position; described as a "Slit/Absent Channel." The average age at time of surgery was 23.4 ± 16.7 years. Diagnoses included idiopathic scoliosis (n = 38) and syndromic scoliosis (n = 15). The average main thoracic Cobb angle was 73° ± 26°. Evaluation of pedicle morphology of the 4 types was also performed in 21 consecutive cases of adolescent idiopathic scoliosis using preoperative computed tomography images. Results. A total of 1021 pedicles with screws placed were evaluated. The average percent per type was as follows: 61.0% type A; 29.2% type B, 6.8% type C, and 3.0% type D. On the convexity, 98.2% of pedicles were type A or B versus 81.5% on the concavity (P < 0.05). There were significant differences between adolescent versus adult idiopathic scoliosis (P = 0.007), and syndromic scoliosis versus adult idiopathic scoliosis (P = 0.017) regarding pedicle morphologic proportions. There was a significant tendency toward a decrease in the proportion of type A pedicles, an increase in the proportion of type B pedicles as the Cobb angle increased (P < 0.0001). Evaluation based on 312 thoracic pedicles in 21 consecutive adolescent idiopathic scoliosis patients using preoperative computed tomography axial images confirmed assumptions of the 4 pedicle types. Conclusion. We propose a classification for pedicle channels describing the osseous anatomy encountered during pedicle probe insertion. Based on the classification, surprisingly, we found during surgery that 90% of thoracic pedicles had a cancellous channel, whereas 7% had a cortical channel and only 3% had an absent channel.
TL;DR: In cases of severe ankylosing spondylitis kyphosis with chin-brow vertical angles beyond 90 degrees, a single stage transpedicular bivertebrae wedge osteotomy and discectomy is an effective corrected method of correction.
Abstract: Study Design: A prospective study was performed in 8 patientswith severe ankylosing spondylitis.Objectives: To observe the feasibility, reliability, and complica-tions of a method of transpedicular bivertebrae wedge osteo-tomy and discectomy to manage the sagittal plane deformity inankylosing spondylitis with chin-brow vertical angles beyond 90degrees.Summary of Background Data: In ankylosing spondylitis, thecorrection of sagittal plane deformity can be achieved bylengthening the anterior elements, shortening the posteriorelements, or a combination of the 2. Neither Smith-Petersenosteotomy, nor pedicle subtraction osteotomy in 1 segment canachieve adequate correction for cases of severe ankylosingspondylitis kyphosis.Methods: From January 2003 to May 2007, 8 patients (3 malesand 5 females) with severe ankylosing spondylitis in ourinstitution underwent a single stage transpedicular bivertebraewedge osteotomy and discectomy. The operation techniqueincludes resection of the posterior elements of 2 adjacentvertebrae, resection of the inferior-posterior aspect of proximalvertebra, and the superior-posterior aspect of the distal vertebra,followed by posterior instrumentation with pedicle screws andspinal fusion. Preoperative and postoperative height, chin-browvertical angle, sagittal balance, and sagittal Cobb angle of thevertebral osteotomy segment were documented. Intraoperative,postoperative, and general complications were registered.Results: The mean follow-up was 18.7±6.1 months (range: 14to 54mo). The mean duration of surgery was 236 minutes(range: 198 to 310min), and the average volume of intraopera-tive blood loss was 2200mL (range: 1600 to 3860mL). Thepatients’ height increased from 120.5±12.0cm to 159.6±12.4cm(P=0.000). The mean chin-brow vertical angle was improvedfrom 102.8±9.7 to 19.3±13.9 degrees (P=0.000). The spinalsagittal Cobb angle of the vertebral osteotomy segment wascorrected from kyphosis 38.6±16.5 degrees to lordosis26.6±10.1 degrees (P=0.000). One patient with the involve-ment of the cervical spine suffered an extension spinal fracture atC5/6 as the operating table was extended. Translation at theosteotomy site occurred in 1 patient during the correction.Fusion of the osteotomy was achieved in all patients, and noloosening or breakage of pedicle screws was found.Conclusions: In cases of severe ankylosing spondylitis kyphosiswith chin-brow vertical angles beyond 90 degrees, a single stagetranspedicular bivertebrae wedge osteotomy and discectomy isan effective corrected method of correction.Key Words: ankylosing spondylitis, kyphosis, osteotomy,discectomy(J Spinal Disord Tech 2010;23:186–191)
TL;DR: Compared with the documented results, variability of the Cobb measurement is reduced by using the developed computer-aided method and this method can help orthopedic surgeons measure the Cobb angle more reliably during scoliosis clinics.
Abstract: Study design Development of a computer-aided Cobb measurement method and evaluation of its reliability. Objectives To reduce the variability of Cobb angle measurement by developing the computer-aided method and to investigate if the developed method is sensitive to observer skill levels or experiences. Summary of background data Therapeutic decisions for scoliosis heavily rely on the Cobb angle measured from consecutive radiographs. The manual Cobb measurement is subject to human errors. The observer error is 3 to 10 degrees resulted from different end-vertebrae selection and/or manually drawing variable best-fit lines to the endplates of the end-vertebrae. Methods A fussy Hough transform technique was used to develop a computer-aided method to detect the vertebral endplates. The Cobb angle, upper end-vertebra, and lower end-vertebra were then measured automatically. The computer-aided method was tested twice by each of 3 observers in 84 posteroanterior radiographs from patients with adolescent idiopathic scoliosis. The intraobserver and interobserver errors were analyzed. Results Both the intraobserver and interobserver reliability analyses resulted in the intraclass correlation coefficients higher than 0.9 for the Cobb angle. The average intraobserver and interobserver errors were less than 3 degree for the Cobb angle, and less than 0.3 levels for both the upper and lower end-vertebral identification. There were no significant differences in the measurement variability between groups of curve location (thoracic, thoracolumbar, and lumbar), curve direction (right and left), curve magnitude (curves less than 25 degree, between 25 and 45 degrees, and more than 45 degree), and observer experience (experienced observer and inexperienced observers). Conclusions Compared with the documented results, variability of the Cobb measurement is reduced by using the developed computer-aided method. This method can help orthopedic surgeons measure the Cobb angle more reliably during scoliosis clinics.
TL;DR: The predictive value of several maturity indicators that reflect growth or remaining growth potential are determined in order to predict timing of the peak growth velocity of total body height in the individual patient with adolescent idiopathic scoliosis.
Abstract: Scoliosis is present in 3-5% of the children in the adolescent age group, with a higher incidence in females Treatment of adolescent idiopathic scoliosis is mainly dependent on the progression of the scoliotic curve There is a close relationship between curve progression and rapid (spinal) growth of the patient during puberty However, until present time no conclusive method was found for predicting the timing and magnitude of the pubertal growth spurt in total body height, or the curve progression of the idiopathic scoliosis The goal of this study is to determine the predictive value of several maturity indicators that reflect growth or remaining growth potential, in order to predict timing of the peak growth velocity of total body height in the individual patient with adolescent idiopathic scoliosis Furthermore, different parameters are evaluated for their correlation with curve progression in the individual scoliosis patient This prospective, longitudinal cohort study will be incorporated in the usual care of patients with adolescent idiopathic scoliosis All new patients between 8 and 17 years with adolescent idiopathic scoliosis (Cobb angle >10 degrees) visiting the outpatient clinic of the University Medical Center Groningen are included in this study Follow up will take place every 6 months The present study will use a new ultra-low dose X-ray system which can make total body X-rays Several maturity indicators are evaluated like different body length dimensions, secondary sexual characteristics, skeletal age in hand and wrist, skeletal age in the elbow, the Risser sign, the status of the triradiate cartilage, and EMG ratios of the paraspinal muscle activity Correlations of all dimensions will be calculated in relationship to the timing of the pubertal growth spurt, and to the progression of the scoliotic curve An algorithm will be made for the optimal treatment strategy in the individual patient with adolescent idiopathic scoliosis This study will determine the value of many maturity indicators and will be useful as well for other clinicians treating children with disorders of growth Since not all clinicians have access to the presented new 3D X-ray system or have the time to make EMG's, for example, all indicators will be correlated to the timing of the peak growth velocity of total body height and curve progression in idiopathic scoliosis Therefore each clinician can chose which indicators can be used best in their practice NTR2048
TL;DR: Thoracic pedicle screw constructs achieved better scoliosis correction compared with fulcrum bending radiographs, and the fulCrum bending corrective index achieved was significantly greater in rigid than flexible curves.
Abstract: Study design A retrospective series of 35 idiopathic scoliosis patients underwent spinal fusion with a segmental thoracic pedicle screw system. Objective To evaluate the amount of scoliosis correction with segmental pedicle screw constructs, and assess whether the fulcrum bending radiograph can predict surgical correction. Summary of background data The fulcrum bending radiograph is highly predictive of actual curve correction based on hook or hybrid systems. However, its predictive value in segmental pedicle screw fixation systems has not been reported. Methods Patients diagnosed with Lenke type 1A and 1B thoracic idiopathic scoliosis who underwent posterior spinal fusion with segmental pedicle screw constructs by single surgeon from January 2000 to December 2005 were reviewed. The fulcrum flexibility rate (FFR) and correction rate were compared. Stepwise linear regression analysis was done and a prediction equation for the postoperative Cobb angle was developed. Results Thirty-five consecutive patients were included. Age at surgery was 14.8 years. Twenty scoliosis deformities were flexible, 15 were rigid. All patients had at least 2-year follow-up. The average preoperative Cobb angle was 58 degrees , fulcrum bending Cobb angle was 28 degrees , and postoperative Cobb angle 15 degrees and 16 degrees at 1 month and 2 years, respectively, after surgery. There was significant difference between FFR (51%) and correction rate at 1 month (72%) and 2 year (70%) after surgery. The difference between fulcrum bending corrective index of flexible (122%) and rigid (203%) curves was statistically significant. Stepwise linear regression analysis showed: Predicted postoperative Cobb angle = 0.012 + 1.75 x age - 0.212 x FFR (R = 0.69, P Conclusion Thoracic pedicle screw constructs achieved better scoliosis correction compared with fulcrum bending radiographs. The fulcrum bending corrective index achieved was significantly greater in rigid than flexible curves. The postoperative Cobb angles could be calculated with a predictive equation.
TL;DR: The FEG demonstrated excellent accuracy and test-retest reliability and correlated very well with the Cobb angle and seemed to correspond most closely with theobb angle measured between the middle of the FEG end blocks.
Abstract: STUDY DESIGN Three experiments to validate the use of the flexible electrogoniometer (FEG) as a tool to measure thoracic kyphosis. OBJECTIVE To investigate the accuracy, test-retest reliability, and concurrent validity of the FEG as applied to the thoracic spine. SUMMARY OF BACKGROUND DATA Thoracic kyphosis is commonly measured by the Cobb angle from lateral radiograph. Other less-invasive tools have been developed, but all yield only static measurements or are restricted to the laboratory. The FEG, which can record joint angles over time outside the laboratory, has been used to measure other joints but has not yet been validated for measurement of the thoracic spine. METHODS First, the FEG was bench-tested against a plurimeter for accuracy. Second, 12 subjects performed 7 functional activities 1 week apart to assess the test-retest reliability. Finally, to examine concurrent validity, 12 subjects underwent radiography in "upright" and "slumped" standing with the FEG attached to the skin over their thoracic spine. Three Cobb angles, which corresponded with the inner, mid, and outer margins, respectively, of the overlying FEG end blocks were compared with the FEG angles. RESULTS The correlation between the FEG and the plurimeter was excellent (r > 0.99, P < 0.0001), although some accuracy was lost at extremes of range. The mean correlation between the first and second measurements was very strong (intraclass correlation coefficient(2,1) 0.92, P < 0.0001; range, 0.89-0.95). The mid-Cobb angle showed the least absolute angular difference from, and was highly correlated with, the FEG angle (r = 0.81, P < 0.01). CONCLUSION The FEG demonstrated excellent accuracy and test-retest reliability and correlated very well with the Cobb angle. The FEG measurement seemed to correspond most closely with the Cobb angle measured between the middle of the FEG end blocks.
TL;DR: The use of extensive and vigorous anterior release with posterior hybrid instrumentation has proved useful and effective in the treatment of these severe deformities; sublaminar wires allow safe gradual correction and even distribution of forces over multiple anchor points improving the correction achieved and decreasing implant-related complications.
Abstract: The surgical management of severe rigid dystrophic neurofibromatosis curves is a demanding procedure with uncertain results. Several difficulties are present in such patients including a poor bone stock, sharp angulation of these dystrophic curves and dural thinning or ectasia. The aim of this work was to review the clinical and radiographic outcomes of three-dimensional correction of severe rigid neurofibromatosis curves analyzing its efficacy, safety and possible complications. Thirty-two patients were followed up for an average of 6.5 years (range 3–9 years). The average age at surgery was 14 years (range 11–19 years). All patients had typical dystrophic curves, and the apex of the deformity was thoracic (n = 13), thoracolumbar (n = 14) and lumbar (n = 5). All patients had a two-staged procedure; an anterior release followed latter by posterior hybrid instrumentation augmented by sublaminar wires. Two wires were usually placed immediately below the proximal anchor, and several sublaminar wires were always passed at the apex of the deformity. There were a total of 142 wires with an average of 6.5 wires/patient (range 5–8 wires). The mean preoperative Cobb angle of the scoliotic curve was 102.2° (range 71°–114°) corrected to an average of 39° (range 16°–49°), and the loss of correction had an average of 4°. The mean preoperative sagittal plane deformity was 49° corrected by an average of 61%, and rotation was corrected by an average of 34%. There were no dural tears during passage of the sublaminar wires, no implant-related complications and no permanent neurologic deficits. The use of extensive and vigorous anterior release with posterior hybrid instrumentation has proved useful and effective in the treatment of these severe deformities; sublaminar wires allow safe gradual correction and even distribution of forces over multiple anchor points improving the correction achieved and decreasing implant-related complications.
TL;DR: It is suggested that in skeletally immature patients with AIS, hybrid instrumentation cannot effectively prevent occurrence of the crankshaft phenomenon, whereas interval and consecutive pedicle screw instrumentation may be more (and equally) efficacious in this regard.
Abstract: STUDY DESIGN: Retrospective. OBJECTIVE: To compare the occurrence of the crankshaft phenomenon in patients with adolescent idiopathic scoliosis (AIS) who underwent hybrid, consecutive pedicle screw or interval pedicle screw instrumentation for posterior spinal fusion. SUMMARY OF BACKGROUND DATA: Scoliosis may progress after posterior spinal fusion in skeletally immature patients with AIS. The crankshaft phenomenon occurs when the anterior column continues to grow in the face of posterior fusion causing characteristic twisting of the fused segment. The optimal surgical method for preventing the occurrence of this complication has not been determined. METHODS: Sixty seven patients with AIS who underwent posterior fusion over a 6-year period were divided into groups according to fixation method: hybrid instrumentation, interval pedicle screw placement, or consecutive pedicle screw placement. Preoperative, postoperative, and follow-up radiographic measures, including Cobb angle, apical vertebral rotation (AVR), apical vertebral transposition (AVT), rib vertebral angle difference (RVAD) and trunk shift (TS) were assessed. The occurrence of the crankshaft phenomenon was determined. RESULTS: The mean follow-up duration was 36 months. There were no between-the-group differences in demographics or preoperative or immediate postoperative measures. At the last follow-up, significant differences among the groups were apparent for Cobb angle, AVR, AVT, RVAD, and TS (all P<0.05). Cobb angle, AVR, AVT, RVAD, and TS significantly increased between the postsurgery and the last follow-up in the hybrid instrumentation group (all P<0.0167). Only TS increased significantly in the 2 other groups. There were 7 cases of crankshaft phenomenon occurrence in the hybrid instrumentation group (33%), but none in the other 2 groups. CONCLUSIONS: These findings suggest that in skeletally immature patients with AIS, hybrid instrumentation cannot effectively prevent occurrence of the crankshaft phenomenon, whereas interval and consecutive pedicle screw instrumentation may be more (and equally) efficacious in this regard.
TL;DR: As the overall prevalence of deep wound infection is relatively high in CP patients after spine fusion, and considering the cost of hospitalization and other related comorbidities, surgeons should recognize these predisposing parameters to prevent deep wound infected patients while correcting curve deformities.
Abstract: BACKGROUND: Infection after spine fusion for neuromuscular scoliosis has been shown to range from 4.2% to 20.0% prevalence. Although there are studies, which have examined deep wound infection and spine fusion surgery as well as risk factors for deep wound infection, there are limited studies evaluating clinical and radiographic factors associated with this complication. We aimed to determine the clinical and operative factors associated with deep wound infection after spine fusion in pediatric patients with cerebral palsy (CP). METHODS: Medical records of 236 pediatric patients, aged between 5.6 and 21 years (mean=13.8 ± 3.4), with CP who underwent spine fusion from 1995 to 2006 were reviewed. Of these, 22 patients had deep wound infection. To assess the differences in clinical, radiographic, and other predisposing factors, we used χ statistic and Fisher exact, and to determine the predisposing factors of deep wound infection, we used binomial regression model. RESULTS: The period prevalence of deep wound infection was 9.3%. In the unadjusted model, body weight, residual postoperative Cobb angle, length of hospitalization, packed red blood cells, and skin breakdown were the factors significantly associated with deep wound infection (P<0.05). After controlling for confounding, skin breakdown due to the instrumentation and residual postoperative Cobb angle were the 2 most potent markers of deep wound infection. There was a significant 4% increased risk of deep wound infection for 1-degree increase in the residual Cobb angle from the noncase mean residual Cobb angle of 23.69 degrees (adjusted risk ratio=1.04; 95% confidence interval, 1.01-1.08). Likewise, compared with those without skin breakdown, those with skin breakdown were 12 times as likely to develop deep wound infection (risk ratio=12.92; 95% confidence interval, 1.00-172.00). CONCLUSIONS: Residual postoperative Cobb angle and skin breakdown due to unit rod instrumentation were the 2 most significant predisposing factors to deep wound infection. Other factors included body weight, packed red blood cells, and length of hospitalization. As the overall prevalence of deep wound infection is relatively high in CP patients after spine fusion, and considering the cost of hospitalization and other related comorbidities, surgeons should recognize these predisposing parameters to prevent deep wound infection in CP patients while correcting curve deformities. LEVEL OF EVIDENCE: Level III retrospective study.