Sagittal Profile Research Articles

Multilevel XLIFs, TLIFs and Grade 2 Posterior Osteotomies for Surgical Correction of Compensated Sagittal Imbalance: Outcomes in 25 Consecutive Adult Degenerative Deformities at Minumum 2 Years Follow-up

Introduction Sagittal imbalance in the adult degenerative spine requires surgical correction to improve pain, mobility and quality of life. Aim of our surgery is to obtain a harmonic, balanced sagittal profile operating a series of adult degenerative kyphoscoliosis by means of XLIFs, TLIFs, SPOs and posterior pedicle screws. Actually, XLIF seems to be the less invasive alternative to PSO to restore LL and achieve anterior fusion, while Grade 2 posterior osteotomies can be useful to further decrease kyphosis. Material and Methods We treated by XLIFs, SPOs and pedicle instrumentations 25 thoraco-lumbar and lumbar degenerative deformities, characterized by a sagittal compensated imbalance (SVA < 50mm), with or without coronal deformity, and distinguished according to the SRS-Schwab classification. All patients were submitted to X-ray screening during pre, post-operative and follow-up periods. Results Mean age was 64 (50–74; M/F 1: 4). Sixteen deformities were type L and 9 type N. Loss of LL was moderate (+) in 14 cases and marked (++) in 11. We performed 50 XLIFs, 15 TLIFs, 48 SPOs. Complication rate was minimal. PT, LL, SVA and TK improved ( p < 0.05), post-operative values were similar to those pre-operatively calculated in 90% of cases and clinical follow-up (mean 29.5; range 24–36), scored using VAS and ODI, was satisfactory in all cases, except for two due to sacro-iliac pain. Conclusion Current follow-up does not allow definitive conclusions. However, the surgical approach proposed seems to be a viable choice usable in these compensated adult deformities, avoiding risks and complications of aggressive PSOs.

A Radiological Evaluation of Effect of a Single Level Trans-Foraminal Lumbar Interbody Fusion (TLIF) on Lumbar Sagittal Parameters

Aim To investigate the effect of a primary single level TLIF on the lumbar sagittal profile (segmental lordosis and total lumbar lordosis) comparing pre-operative, intra-operative and post-operative radiographs in patients with lumbar spine degenerative disease. Methods Patients over the age of 16 who underwent a single-level interbody fusion for degenerative stenosis and/or spondylolisthesis without scoliosis between March 2008 and March 2014 were reviewed. Age, gender, surgical level, surgical approach, facetectomy (unilateral vs bilateral) were recorded. Standardized pre and early and 6 month postoperative upright radiographs as well as an intra-operative lateral radiographs were analyzed for the pelvic incidence (PI), segmental lordosis (SL) at the TILF level and total lumbar lordosis (TL). Data analysis was performed after confirming normality using a paired t-test and is presented as mean (SD). p-value < 0.05 was considered significant. Results 69 patients were reviewed. The mean age was 58.6 (13.6) years, 39 males (56.5%), a Wiltse approach was used in 30 (43.5%) while 39 had a midline posterior approach. Segments operated were L2/L3 (1 case), L3/L4 (6), L4/L5 (43), L5/S1 (19) and bilateral facetectomy was performed in 13 (18.8%). SL changed from 15.2° (7.3) preoperatively to 20.4° (7.7) intraoperatively ( p-value < 0.0001) but measured 17.9° (7.2) ( p-value < 0.0001) on early postoperative images and 17.2° (7.3) at 6 months follow up ( p-value= 024). The total improvement in SL at 6 months was 2° (6.7), ( p-value= 0.001). TL change was insignificant on the early postoperative X-rays (48.5° (12.4) to 47.2° (11.3), p-value= 0.37) but significantly increased to 53.1° (11.5) at six months ( p-value < 0.0001) with a total improvement of 4.6° (10) ( p-value= 0.001). The mean pelvic incidence was 59.7° (11.2). The cage subsided in 11 (15.9%) cases and we had no metal work loosening. Conclusion At the level of the TLIF, much of the lordosis achieved intra-operatively is lost once the patient mobilizes. An improvement in the total lumbar lordosis at 6 months following surgery is likely to be due to the decompression component of the surgical intervention.

Anterior Coloumn Reconstruction with Stand Alone Titanium Cage, without Anterior Plating in Tuberculosis Cervical Spine. An Experience of 47 Patients

Introduction Tuberculosis is a common problem specially in under developed countries. Tuberculosis of the vertebral column constitutes nearly 50% of all lesions of osteoarticular tuberculosis. The commonest site for the disease is in the peridiscal region. Treatment option usually is anti tuberculous chemotherapy but in some patients usually with severe pain and involving neurology, instability, large abcess, surgery is recommended. To our knowledge there is not a single publication in literature in which standalone titanium cage and bone graft without anterior plating is used in the treatment of TBS. The aim of this study is to evaluate the efficacy of standalone titanium mesh cages in TB cervical spine. Material and Methods A retrospective study of 47 patients with cervical tuberculous spondylitis (TBS) was performed at Ghurki trust teaching hospital. This study approved by the Institutional Review board and the ethics committee, included 47 patients with TBS of cervical spine who gave their informed consent to be included in the research. All patients had radical debridement, decompression, anterior coloumn reconstruction and instrumentation with standalone titanium cage without anterior plating filled with autologous iliac bone graft. The diagnosis of TBS was based on clinical correlation including night fever, loss of weight, fatigue and neck pain, laboratory investigations including ESR, CRP and tuberculin test were done in all patients. Visual analogue score (VAS) and frankel scoring system was used to score pain severity and grade neurological status. ATT was started preoperatively. The radiographic assessment included preoperative standard anteroposterior and lateral views. Cobbs methos was used to measure the sagittal profile. Results 61.6% patients fell in age group 3–35 years and 28.4% fell in group 36–70 years of age. 26 were men and 21 were women. Out of all patients 26 had pre op frankel grade E and 4pts had grade D and 10 pts had grade C and 2 pts had grade B and five pts had grade A preoperatively. Post operatively one patient of grade A remained same while other four improved to grade C in follow up and rest of all pts. improved to grade E in two year follow up. Pre-op cob's angle was 39.06 ± 10.92 (Mean±SD) which improved to -5.51 ± 4.77 (Mean±SD). P value is < 0.05. In comparison of visual analogue score there is also statistically significant difference in pain improvement. All patients had single stage radical debridement, decompression and instrumentation. Anterior coloumn reconstruction was done in all patients using standalone titanium cage. Conclusion The use of titanium cages effectively restores the sagittal deformity in TB spine with no donor site morbidity.

Why X-rays are not reliable to assess sagittal profile: a cross sectional study.

X-rays are the gold standard evaluation for sagittal plane deformities even if, to see the spine, it's necessary to move the arms from the resting position to a forward one. The postural impact of arm positions has never been verified. The aim of this study is to measure the effect of arm positioning on surface topography measure. cross sectional. 83 consecutive adolescents (50 hyperkyphosis, 33 scoliosis). Hardware: 4-D Formetric. Methods: each subject has been consecutively evaluated in normal standing, then with progressive extension of the shoulders with extended arms (45°, 90°, 135°, 180°), then with arms crossed on the chest (CROSS) and with flexion of the shoulders and elbows, with hands steady on the shoulders (REST). All sagittal parameters given by Formetric have been considered. ANOVA for total and sub-groups. Results. The absolute differences of angles from the standing position ranged from 4.8° to 13.3° (kyphosis) and from 4.6° to 10.4° (lordosis): they were statistically significantly different with rare exceptions. The biggest differences have been found with REST and 180°; the lowest with 45°, and CROSS. Lordosis and kyphosis did not change in the same direction, nor symmetrically: while kyphosis decreased with progressive arm extension, lordosis reached a maximum increase at 90-135°; REST and CROSS did not show consistent variations of lordosis and kyphosis. Changes were not consistent in several adolescents, and did not allow to find an ideal position. These results showed that arm position changes spinal posture, at least when measuring with surface topography. According to these results, it does not exist an optimal position comparable with the normal standing; moreover, it is not possible to reconstruct in individual patients what the real standing angles would be without moving the arms. Surface devices may possibly be more ecologic measurement instruments than radiographs because they allow the patient to maintain the normal position of their arms and so are more reliable.

The effect of magnetically controlled growing rod on the sagittal profile in early-onset scoliosis patients

The effect of magnetically controlled growing rod on the sagittal profile in early-onset scoliosis patients

Is There a Gender-Specific Full Body Sagittal Profile for Different Spinopelvic Relationships? A Study on Propensity-Matched Cohorts

DesignRetrospective review. ObjectiveTo evaluate gender-related differences in compensatory recruitment to progressive sagittal malalignment. Summary of Background DataRecent research has elucidated compensatory mechanisms recruited in response to sagittal malalignment, but gender-specific differences in compensatory recruitment patterns is unknown. MethodsSingle-center study of patients with full body x-rays. A female group was propensity matched by age, body mass index (BMI), and pelvic incidence (PI) to a male group. Patients were then stratified into five groups of progressive PI–lumbar lordosis (LL) mismatch (<0°, 0°–10°, 10°–20°, 20°–30°, >30°). Differences between PI-LL groups were assessed with analysis of variance, and between genders by unpaired t test. Knee flexion to pelvic tilt (PT) ratio was computed and compared between genders. Multivariate regression to develop predictive models for PT was performed for each gender, first with spinopelvic parameters and subsequently with inclusion of lower limb parameters. ResultsA total of 942 patient visits were included: 471 females (mean age 54 years, BMI 27, PI 51°) and 471 males (mean age 52 years, BMI 27, PI 51°). At the lowest level of malalignment, females had greater PT and less knee flexion. With progressive malalignment, females continued to exhibit a pattern of greater pelvic retroversion and less knee flexion compared to males. Hip extension was higher in females with progressive PI-LL mismatch groups. Both genders progressively recruited knee flexion and pelvic retroversion with increased PI-LL mismatch, except that at the higher PI-LL mismatch groups, only males continued to recruit knee flexion (all p < .05). Inclusion of lower limbs in the regression for PT markedly improved correlation coefficients for females but not for males. ConclusionsWith progressive sagittal malalignment, men recruit more knee flexion and women recruit more pelvic tilt and hip extension. Knee flexion is a possible mechanism to gain pelvic tilt for females whereas for males, knee flexion is an independent compensatory mechanism.

Congenital Scoliosis (Mini-review).

Congenital scoliosis is a lateral deformity of the spine with a disturbance of the sagittal profile caused by malformations of vertebra and ribs. Typically, early surgical intervention is the suggested treatment (before three-years-old) for young patients with congenital scoliosis. While a previous study was conducted in 2011 to investigate long-term studies supporting the necessity for this recommendation and no evidence was found, this current review, is an updated search for evidence published from 2011 through March 2015. This also failed to find any prospective or randomized controlled studies to support the hypothesis that spinal fusion surgery in patients with congenital scoliosis should be considered as evidence-based treatment. Contradictory results exist on the safety of hemivertebra resection and segmental fusion using pedicle screw fixation. When using the VEPTR (vertical expandable prosthetic titanium rib) device, studies show a high rate of complications exist. It is difficult to predict the final outcome for patients with congenital scoliosis. However, it is possible that many patients with congenital scoliosis may be able to avoid spinal surgery with the application of advanced bracing technology. Therefore, it is only prudent to advocate for conservative management first before spinal surgery is considered.

A telescopic vertebral endoprosthesis for subaxial cervical fusion

The study purpose was to develop an anterior subaxial cervical fusion technique using a new telescopic vertebral graft (VG) construction and to introduce the technique into clinical practice. We analyzed existing VG constructions used in anterior interbody fusion at the cervical spine level and developed our own variant of a vertical, cylindrical, telescopic, mesh, vertebral endoprosthesis as well as a technique of its placement to replace bodies of the cervical vertebrae. The technique was used in 11 patients with spinal trauma. The orthopedic and neurological status and outcomes of surgical treatment were assessed using ASIA/IMSOP, Odom, and VAS scales. The first cases of replacement of a resected vertebra by the proposed construction indicate the advisability of using this VG to restore the sagittal profile, stabilize the operated spinal motion segment, and create conditions for the formation of an adequate supporting bone block. The graft construction can be filled with a significant amount of a filler and makes it possible to add and tighten the filler after placing the graft into the operating position. The study demonstrated the construct efficacy. No postoperative complications associated with the use and placement of the telescopic constructions was observed.

SURGICAL TREATMENT OF SPINAL PATHOLOGY IN CHILDREN WITH CAUDAL REGRESSION SYNDROME: ANALYSIS OF LONG-TERM OUTCOMES

Objective. To analyze long-term outcomes of surgical treatment of spinal column pathology in children with caudal regression syndrome. Material and Methods . The study included 12 patients aged 1.5 to 9 years with caudal regression syndrome. To determine the type of caudal regression the Renshaw classification was used. Surgery involved correction of kyphotic deformity of the spine and elimination of instability, and spinal-pelvic fusion including instrumented fixation of the spinal-pelvic segment with restoration of sagittal profile and support ability of the spine and creation of bone block by placement of split cortical allografts along the spinal implant. Results . Children with types III and IV caudal regression syndrome underwent spinal-pelvic fusion, which allowed achieving strong fixation of the spinal-pelvic segment and ensured its stability at patient’s verticalization. Conclusion . Multi-anchor transpedicular instrumentation in combination with spinal-pelvic fusion with cortical allografts allows eliminating abnormal kyphosis, achieving bone block formation, and retaining the achieved result in the late postoperative period.

Segmental Pelvic Correlation (SPeC): a novel approach to understanding sagittal plane spinal alignment

Background ContextLumbar lordosis (LL) correlates with pelvic morphology, and it has been demonstrated that as LL increases, the inflection point and apex of lordosis move cranially. This suggests that each segment of the lumbar spine relates to pelvic morphology in a unique way. ObjectivesThis study aimed to establish whether there is a direct relationship between pelvic morphology and lumbar segmental angulation in the sagittal plane. Study DesignA retrospective analysis of 41 patient radiographs was carried out. Patient SampleInclusion criteria included patients with full length standing anterioposterior and lateral radiographs of the spine from base of occiput to proximal femora, with clearly visible vertebral end plates from T12 to S1 and a thoracic kyphosis (TK) and LL within the normal range. Patients were excluded if they had a coronal spinal deformity affecting the lumbar spine, chronic back pain, spondylolisthesis, spondylolysis, congenital scoliosis, or skeletal dysplasia. Outcome MeasuresSpinopelvic radiographic parameters of pelvic incidence (PI), LL, TK, and segmental angulation at each level from L1 to the sacrum were the outcome measures. MethodsForty-one lateral whole spine radiographs with normal sagittal profiles from the spinal deformity clinic were retrospectively reviewed. Pelvic incidence, LL, TK, and segmental angulation at each level from L1 to the sacrum were measured (from end plate to end plate), distinguishing the vertebral body and intervertebral disc contribution. Pearson correlation coefficients were used to analyze any relationship between pelvic parameters and segmental angulation. ResultsA strong correlation was found between PI and LL. Pelvic incidence correlated strongly with the L1 and L2 motion segments (p=.0001, p=.03), notably at the intervertebral discs but not the L4 and L5 motion segments. The proportion of total LL contributed at L4–L5 and L5–S1 reduced as PI increased. ConclusionsPelvic incidence can predict segmental angulation. Although the majority of LL is produced at the L4 and L5 motion segments, cephalad lumbar segments sequentially become increasingly important as PI increases. This describes a continuum where the L1 and L2 motion segments crucially fine-tune total LL according to PI. This allows segmental abnormalities to be identified when compensation in adjacent segments maintain normal total LL. It also paves the way for anatomical segmental reconstruction in degenerative adult deformity based on pelvic morphology.

Surgical treatment of children with idiopathic thoracolumbar scoliosis using transpedicular spinal systems

Purpose of the study. Evaluation of the surgical treatment of children with idiopathic scoliosis of thoracolumbar localization. Materials and methods. Surgery was performed on 33 patients aged from 13 to 17 years with a curve approximating 42°-123°, according to Cobb. Surgical correction of the deformity was performed using three tactical options with the use of a transpedicular multi-basic metallic device. Results. In idiopathic thoracolumbar scoliosis, the surgical correction ranged from 74% to 100%. Loss of correction in the follow-up period from 2 to 5 years was 2°-4°. Conclusion. Surgical treatment of children with idiopathic thoracolumbar scoliosis depends on the degree of the main curve, spinal mobility, and the patient's age. Application of a multi-basic transpedicular metallic device allows significant correction of the angle of the curve, a true de-rotation of vertebral bodies at the apex of the curve to be performed, and the frontal and sagittal profile of the spine to be restored while maintaining the results achieved in the late postoperative period.

Concurrent Validity of the Biostage for Assessment of Lower Extremity Joint Angles

The objective of the current study is to establish the concurrent validity of the Biostage, as a novel markerless motion analysis system, in measuring the lower extremity joint angles during a prescribed motion. Traditional markerless motion analysis system (e.g., Vicon Motus) was used as the baseline. A laboratory study involving 18 healthy young adults was conducted. Both the Biostage and the Motus were used to collect sagittal lower extremity joint angles while the subjects performed squats. The results indicated generally similar sagittal joint angle ensemble profiles between the systems. Significant differences in peak joint angles were found in hip joint, but not in ankle and knee joints. In conclusion, the study findings supported the concurrent validity of the Biostage, as a novel markerless motion analysis system, in measuring lower extremity joint kinematics.

Sagittal Thoracic and Lumbar Spine Profiles in Upright Standing and Lying Prone Positions Among Healthy Subjects: Influence of Various Biometric Features.

A prospective study was performed on the assessment of both thoracic and lumbar spine sagittal profiles (from C7 to S1). To propose a new noninvasive method for measuring the spine curvatures in standing and lying prone positions and to analyze their relationship with various biometric characteristics. Modifications of spine curvatures (i.e. lordosis or kyphosis) are of importance in the development of spinal disorders. Studies have emphasized the development of new devices to measure the spine sagittal profiles using a noninvasive and low-cost method. To date, it has not been applied for analyzing both lumbar and thoracic alterations for various positioning. Seventy-five healthy subjects (mean 22.6 ± 4.3 yr) were recruited to participate in this study. Thoracic and lumbar sagittal profiles were assessed in standing and lying prone positions using a 3D digitizer. In addition, several biometric data were collected including maximal trunk isometric strength for flexion and extension movement. Statistical analysis consisted in data comparisons of spine profiles and a multivariate analysis including biometric features, to classify individuals considering low within- and high between-variability. Kyphosis and lordosis angles decreased significantly from standing to lying prone position by an average of 13.4° and 16.6°, respectively. Multivariate analysis showed a sample clustering of 3 homogenous subgroups. The first group displayed larger lordosis and flexibility, and had low data values for height, weight, and strength. The second group had lower values than the overall trend of the whole sample, whereas the third group had larger score values for the torques, height, weight, waist, body mass index, and kyphosis angle but a reduced flexibility. The present results demonstrate a significant effect of the positioning on both thoracic and lumbar spine sagittal profiles and highlight the use of cluster analysis to categorize subgroups after biometric characteristics including curvature measurement. N/A.

The role of single-stage posterior debridement, interbody fusion with titanium mesh cages and short-segment instrumentation in thoracic and lumbar spinal tuberculosis.

The aim of this paper was to retrospectively analyze the clinical efficacy and feasibility of thoracic and lumbar spinal tuberculosis treated by single-stage posterior debridement, interbody fusion with titanium mesh cages (TMC), and combined short-segment instrumentation. Fifteen patients with no more than two vertebral bodies involving thoracic and lumbar tuberculosis were collected from January 2006 to January 2010, performed by single-stage posterior debridement, interbody fusion with TMC and posterior short-segment fixation. The clinical efficacy was evaluated based on the data of the 10-point Visual Analogue Scale (VAS), neurological status, kyphosis angle, erythrocyte sedimentation rate, and C-reactive protein, which were collected at a certain time. The average duration of surgery was 135 minutes. All the patients were followed up for a period ranging from 18 to 48 months (mean 28.9±6.44 months). The VAS score was improved from 8.47±1.13 (range 7-10) before surgery to 2.1±1.7 (range 0-2) after surgery. Correction of segmental kyphotic deformity was 24.2±6.59°. Neither the postoperative change of the position of titanium mesh cage nor any posterior instrumentation failure was recorded. The situation of 13 patients with incomplete neurologic lesions before surgery was improved after surgery. Patients with thoracic and lumbar spinal tuberculosis can be successfully treated by posterior debridement, interbody fusion with TMC combining short-segment instrumentation. The presence of the TMC anteriorly at the site of tubercular spondylitis has no negative influence on the course of infection healing, and additionally they stabilize the affected segment maintaining sufficient sagittal profile.

High Density Pedicle Screws through Posterior Only Approach for Surgical Correction of Severe Adolescent Idiopathic Scoliosis &gt; 70o

Background Data: The classic treatment of severe rigid adolescent idiopathic scoliosis (AIS) was performed by combined anterior and posterior surgery which carries higher morbidity to the patient. Recently, posterior only surgery using allpedicle screws has been used for treatment of severe AIS with many advantages over combined approaches.Purpose: To evaluate the safety and effectiveness of high density pedicle screws through posterior only approach in correction of severe cases of adolescent idiopathic scoliosis (AIS) with curves > 70o. Study Design: Prospective cohort study. Patients and Methods: Between 2012 and 2014, fourteen patients were surgically treated for severe AIS with curves > 70o and were prospectively followed up for a minimum of 1 year (Range 1-4 years). Clinical outcomes were evaluated using SRS- 22 questionnaire. All patients were classified according to Lenke et al classification.Major and minor curves Cobb angle as well as sagittal parameters were measured on whole spine X-rays. Side bending films were used to assess curve flexibility. High density pedicle screws and multiple Ponte osteotomies were used in all patients. Five patients required asymmetrical pedicle subtraction osteotomy due to very rigid curve. Results: This study included 14 patients (8 females, 6 males).The mean age at time of surgery was 17.4 years (range 14-24 years). The mean correction rate for the coronal Cobb angle of the major and minor curves was 73.7% (80.4o preoperativeand 21.7o postoperative) and 68.7% (51.5o preoperative and 19.63o postoperative) respectively. The mean thoracic kyphosis angle was 44.2o preoperatively, 28.55o postoperatively and 28.1o at latest follow up. The mean SRS-22 questionnaire scores improved significantly from 2.8 preoperatively to 3.7 at the final follow up (P>0.001). No cases of pseudarthrosis, metal failure or neurological deficits were encountered. One patient with asymmetrical PSO developed hemothorax that was managed with chest tube insertion and follow up. Conclusion: High density pedicle screws through posterior only approach is a safe and effective method in treatment of severe AIS. It can achieve coronal curve correction comparable to combined anterior and posterior approaches without the morbidity of combined approaches. It also restores the sagittal profile leading to good functional outcomes and better quality of life. (2014ESJ073)

Vertebral coplanar alignment technique: a surgical option for correction of adult thoracic idiopathic scoliosis.

Previous studies have demonstrated vertebral coplanar alignment (VCA) as an effective surgical option for adolescent idiopathic scoliosis (AIS). The purpose of this study is to analyze the outcome of VCA for the surgical correction of adult idiopathic scoliosis (AdIS). 35 AdIS patients (mean age: 24.2 years) undergoing VCA-instrumentation were reviewed. The main thoracic curve and thoracic kyphosis (TK, T5-T12) were evaluated preoperatively, immediate postoperatively, and at the final follow-up (>1 year). All patients were stratified by the TK modifier before surgery: "+" (TK, >40°), "-" (TK, <10°), and "N" (TK, 10°-40°) for normal. The apical vertebral body-to-rib ratio (AVB-R), rib hump (RH), and rotational angle to sacrum (RAsac) were measured to assess the correction of rotational deformity. Quality of life was evaluated with SRS-20 questionnaires. The main thoracic curve (59.1° vs. 19.3°, P < 0.001) and rotational deformity (AVB-R: 2.4 vs. 1.7 %, P < 0.001, RH: 34.9 vs. 19.1 mm, P < 0.001, RAsac: 19.6° vs. 11.9°, P < 0.001) were significantly reduced with surgery. Sagittal deformity improved significantly in group "+" (51.4° vs. 31.6°, P < 0.001) and group "-" (6.2° vs. 20.1°, P < 0.001), while no significant postoperative change in TK was observed in group "N" (23.5° vs. 26.3°, P = 0.270). Patients were followed for an average of 18.7 months with no significant loss of correction. SRS scores improved greatly from 57.7 preoperatively to 71.6 at the final follow-up. VCA can be effectively used for the correction of the coronal and rotational deformity, with better sagittal profile restoration in adult thoracic idiopathic scoliosis with sagittal malalignment.

Selective Thoracic Fusion of Lenke I and II Curves Affects Sagittal Profiles But Not Sagittal or Spinopelvic Alignment: A Case-Control Study.

Literature review and retrospective case-control study (level 3 evidence) examining 50 adolescent idiopathic scoliosis (AIS) (Lenke I or II curve) cases with 32 healthy controls of the same age. The sagittal profiles were measured preoperatively, 6 months, and 2 years after surgery and compared with those of age-matched controls at baseline. The purpose of this study is to compare baseline sagittal profiles of AIS Lenke I and II curves with age-matched healthy controls and at 6 months and 2 years after surgery, as well as with previously published reports. Sagittal alignment and profiles have gained significant attention in spinal deformity outcomes. The sagittal profile of patients with AIS has been previously reported, as well as the effects of surgical correction, with inconsistent results and no clear references to nonscoliotic controls. Baseline sagittal profiles of 50 patients presenting with Lenke I or II AIS curves treated with selective thoracic fusion were compared with 32 age-matched controls without spinal pathology. These values were also measured at 6 months and 2 years postoperatively to examine effects of selective thoracic fusion over time. Sagittal parameters examined include pelvic incidence, pelvic tilt, C7 plumb line (sagittal vertical alignment), thoracic kyphosis, and lumbar lordosis. A literature review was performed comparing previously published data. Data are presented as mean (95% confidence interval). P value of less than 0.05 was considered significant. Interobserver reliability (Cohen κ= 0.49-0.95). All demographic and preoperative sagittal alignment parameters were comparable between controls and patients with AIS prior to surgery. After selective thoracic fusion, thoracic kyphosis decreased significantly from baseline (25.4º [21.6-29.2] vs. 15.3º [12.8-17.8]; P < 0.001) at 6 months and at 2 years (10.3º [7.5-13.1]; P < 0.001). The lumbar lordosis significantly decreased at 6 months from baseline (54.5º [28.6-80.5] vs. 61.8º (33.4-90.1); P < 0.001) and at 2 years (55.4º [29.0-81.9]; P < 0.001). Sagittal vertical alignment, pelvic tilt, and pelvic incidence were comparable between controls and patients with AIS at baseline and did not change with surgery. Adolescents with Lenke I or II curves have comparable sagittal profiles with those of healthy controls of the same age. This suggests that Lenke I and II curves may not be hypokyphotic as previously thought. After selective thoracic fusion, patients with AIS have a significantly decreased thoracic kyphosis, which is accompanied by reciprocal changes in the noninstrumented lumbar curve. Sagittal vertical alignment and pelvic tilt are not significantly affected. These results agree with previous reports, which suggest that constructs with pedicle screws have a higher impact on sagittal curves but do not affect sagittal or spinopelvic alignment. The long-term effects of abnormal sagittal profiles need further clarification. 3.

Change in Pelvic Sagittal Parameters with Growth in Children with Adolescent Scoliosis

Introduction Commonly measured spinopelvic parameters (pelvic incidence, sacral slope, and pelvic tilt) have an effect on global sagittal balance of the spine. It was shown previously by cross-sectional studies that pelvic incidence increases with growth in children. But this change was not demonstrated in longitudinal radiological follow-up studies. In this study, we aimed to investigate the changes in spinopelvic parameters with growth in surgically treated AIS patients. Methods Whole body lateral radiographs eligible for spinopelvic measurements with radiological follow-up before and after skeletal maturity of AIS patients treated surgically were evaluated. First evaluations are made on preoperative radiographs of AIS patients (Risser O or 1). Second evaluations were made on postoperative radiographs taken after skeletal maturity (Risser 5). On whole body lateral radiographs pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), lumbar lordosis between L1 cranial endplate and S1 endplate (LL), and thoracic kyphosis between cranial endplate of T5 and caudal endplate of T12 (TK) were performed using Centricity DICOM software (General Electric). Measurements were made by two observers. Intra- and interobserver reliabilities were also evaluated by repeat measurements. Intra- and interobserver reliabilities for measurements were evaluated by intraclass correlation (ICC). Results A total of 171 surgically treated cases for AIS were reviewed. Of them, 33 cases had radiological follow-up data before and after skeletal maturity with lateral X-rays eligible for spinopelvic parameters measurement. Mean interval between evaluations was 7.49 years. Intra- and interobserver reliabilities for measurements were accepted as “good” with ICC values between 0.951 and 0.989. A significant increase in PI and SS was observed before and after skeletal maturity (46.32 ± 11.61 vs. 52.14 ± 11.69 degrees and 38.14 ± 7.57 vs. 43.19 ± 7.46 degrees, respectively). Increase in LL was also statistically significant and correlated with PI (53.38 ± 9.53 vs. 61.92 ± 10.48 degrees). Changes in TK and PT were not significant. Conclusions Results were concordant with previous cross-sectional and anthropometric studies regarding increase in pelvic incidence by growth. It is also concluded that overall lumbar lordosis is influenced by pelvic incidence both before and after skeletal maturity. As thoracic kyphosis is mainly influenced by instrumentation, no significant difference and relation with spinopelvic parameters were encountered. As reported previously, sagittal profile changes are well tolerated in adolescents, there was no major change in PT. But concerning long fusions, change in pelvic incidence and sacral slope can have a substantial effect on long sagittal profile of surgical candidates.

The Effect of Metal Density on Coronal and Sagittal Curve Correction in Thoracic Adolescent Idiopathic Scoliosis

Introduction The literature is contradictory regarding the effect of metal density on correction of thoracic AIS. Given the rising cost of surgery for AIS, instrumentation should be used rationally. We aim to assess the impact of metal density on coronal and sagittal correction of AIS and assess if larger, less flexible curves necessitate high metal density. Material and Methods It is a retrospective multicenter case series. Inclusion criteria: Lenke 1–2 AIS, curve flexibility assessed by fulcrum-bending technique, single stage posterior only surgery, constructs using &gt; 80% screws, variable metal density, and &gt; 2-year follow-up. Outcome measures: Coronal main thoracic (MT) and lumbar curve correction, fulcrum-bending correction index (FBCI), thoracic kyphosis, lumbosacral lordosis, metal density (number of instrumented pedicles vs. total available), and fusion length. Surgical technique: Standard technique used in all centers employed extra hard titanium–aluminum–niobium alloy 6 mm diameter rods (DePuy Synthes, Raynham, Pennsylvania, United States) with reduction of the curvature via cantilever-segmental translation maneuvers. Implant location and density was according to curve stiffness and intraoperative bone density. The majority of the implants were on the thoracic curve convexity. Analysis: Bivariate analysis of outcome measures. Given the numerous correlations performed, a Bonferroni corrected p value was used, p &lt; 0.005. Two groups of pairs matched by curve type and exact fusion levels but differing MT curve magnitude were compared using student t-test. Outcomes for the quartiles of preoperative MT flexibility were compared using an ANOVA. Results A total of 106 patients, 94 were female patients. A total of 78 patients had Lenke 1 and 28 had Lenke 2. Mean age was 14 years. Bivariate analysis: No significant correlations were present between metal density and coronal curve correction rates of the MT (r = 0.13, p = 0.19) or lumbar curves (r = ␂ 0.15, p = 0.12) or FBCI; MT (r = ␂ 0.1, p = 0.31), lumbar (r = 0.00, p = 0.97). Metal density had no effect on change in thoracic kyphosis (r = 0.22, p = 0.04) or lumbosacral lordosis (r = 0.27 p = 0.01). Longer fusion length was associated with greater loss of thoracic kyphosis (r = ␂ 0.31, p = 0.003) and less postoperative thoracic kyphosis (r = ␂ 0.31, p = 0.003) but did not affect lumbosacral lordosis. Curve magnitude: Two groups of 21 matched cases from preoperative MT curve magnitude (&lt; 70 vs. ≥ 70 degrees) treated with comparable metal density (54 vs. 57%, p = 0.4) had equivalent MT and lumbar curve correction rates and FBCI. Sagittal profile changes did not differ significantly. Flexibility: No significant differences in MT, lumbar, and sagittal curve changes were present among the four MT flexibility quartiles (&lt; 32, 33–43, 43–51, 52–87%) despite all groups receiving comparable metal density (58, 58, 60, 62%, p = 0.2). Conclusion Metal density does not affect coronal and sagittal plane correction in surgery for thoracic AIS. Longer fusion length adversely affects sagittal profile. Larger and less flexible curves do not necessarily require high metal density.

Retraction note: Comparison of the sagittal profiles among thoracic idiopathic scoliosis patients with different Cobb angles and growth potentials.

Previous studies have demonstrated that pelvic incidence and sacral slope are significantly greater in idiopathic scoliosis patients compared with normal adolescents. However, whether these sagittal parameters are related to the progression of scoliosis remain unknown. The present was designed to determine the differences in the sagittal profiles among thoracic idiopathic scoliosis patients with different potentials for curve progression. Ninety-seven outpatient idiopathic scoliosis patients enrolled from June 2008 to June 2011 were divided to three groups according to different Cobb angles and growth potentials: (1) non-progression of thoracic curve group, Risser sign of 5 and Cobb’s angle < 40°; (2) moderate progression of thoracic curve group, Risser sign of 5 and Cobb’s angle ≥ 40°; and (3) severe progression of thoracic curve group, Risser sign ≤ 3 and Cobb’s angle ≥ 40°. All patients underwent whole spinal anteroposterior and lateral X-ray in standing position, and the sagittal parameters were measured, including thoracic kyphosis, lumbar lordosis, sacral slope, pelvic incidence, and pelvic tilt. The average thoracic scoliosis Cobb’s angle in the non-progression group was significantly less than that in the moderate progression group (P < 0.01) and severe progression group (P < 0.01), but there was no statistical difference in the average thoracic scoliosis Cobb’s angle between the severe progression group and moderate progression group. The average thoracic kyphosis angle in the severe progression group (9° ± 4°) was significantly smaller than that in the non-progression group (18° ± 6°, P < 0.01) and moderate progression group (14° ± 5°, P < 0.05). No statistical differences were present in the average lumbar lordosis, sacral slope, pelvic incidence, and pelvic tilt among the three groups. Thoracic hypokyphosis is strongly related with the curve progression in thoracic idiopathic scoliosis patients, but not pelvic sagittal profiles.