Smaller Lumbar Lordosis Research Articles

Patterns of sitting spinal alignment in non-ambulatory scoliosis patients with paraplegia: an observational study.

To classify sagittal spinopelvic alignment patterns of non-ambulatory scoliosis patients with paraplegia based on lateral sitting radiographs and explore their relation to clinical background and physical function. We reviewed non-ambulatory scoliosis patients with paraplegia, excluding those with prior spinal surgery from a single-center database. Alignment patterns in sitting postures were classified into slump sitting (SS) and erect sitting (ES) based on the most posterior edge of the spine's location on lateral sitting radiographs. Radiographical spinopelvic sagittal alignment, demographics, and physical functions were analyzed. Clinical scoring for physical functions included Hoffer's ambulator classification, Hoffer's modified sitting classification, and the Modified Ashworth Score (MAS) for the severity of spasticity in the lower extremities. Percentages of patients without spasticity, with MAS of 0 indicating "no spasticity." were also compared between the two alignment patterns. Of 172 patients screened, 86 met inclusion criteria, revealing two distinct alignment patterns: SS showed greater thoracic kyphosis, smaller lumbar lordosis, pelvic retroversion, and hip hyperflexion compared to ES. No significant differences in demographic data or curve patterns were observed between groups. The SS group had a significantly higher percentage of patients without spasticity compared to the ES group (39.2% vs. 14.3%, P = 0.016). Identified were two distinct sagittal alignment patterns in seated scoliosis patients with paraplegia, with potential influences from spasticity in the lower extremities. Recognizing these patterns can aid in assessing the function of sitting balance that includes the hip joint and in optimizing strategies for the treatment of scoliosis patients with paraplegia.

Exploring the impact of mild-to-moderate foraminal stenosis at L5−S1 on clinical outcomes following L4−5 posterior lumbar interbody fusion

BACKGROUND CONTEXTPatients scheduled for L4−5 PLIF often have FS at L5-S1. However, data on the clinical and radiographic outcomes of cases with mild-to-moderate L5−S1 FS are lacking, which may affect clinical outcomes or require additional surgery after L4−5 fusion. PURPOSETo evaluate the clinical and radiographic outcomes of L4−5 PLIF in patients with and without mild-to-moderate L5−S1 FS, with a primary focus on the association between L5−S1 FS and postoperative clinical outcomes including back pain, leg pain, and scores on the oswestry disability index (ODI) and EuroQol 5-dimension (EQ-5D). STUDY DESIGNRetrospective comparative study. PATIENT SAMPLEA retrospective review of patients who underwent L4−5 PLIF from 2014 to 2018. The patients were divided according to the presence of mild-to-moderate FS at L5−S1. OUTCOME MEASURESClinical assessment included the pain visual analog scale (VAS), ODI, and EQ-5D score. Radiographic assessments included spinopelvic parameters and grades for central and foraminal stenosis. METHODSClinical outcomes were assessed using validated outcome measures at preoperative, 6-month, 12-month, and 36-month follow-up visits. Radiographic evaluations were performed using preoperative and postoperative radiographs. Foraminal stenosis was assessed qualitatively using MRI with a grading system from none to severe and quantitatively by measuring changes in the foraminal area on CT. RESULTSAmong 186 patients, 55 were categorized as the FS group and 131 as the non-FS group. The FS group was older (p=0.039) and had more severe central stenosis at L5−S1 (p=0.007) as well as more severe FS at both L4−5 and L5−S1 (both p<0.001). Preoperative disc height (p<0.001), C7-S1 sagittal vertical axis (p=0.003), lumbar lordosis (p=0.005), and pelvic incidence–lumbar lordosis mismatch (p=0.026) were more aggravated in the FS group. The FS group showed inferior clinical outcomes at the final follow-up in terms of back pain (p=.010) and ODI score (p=.003). CONCLUSIONThe presence of mild-to-moderate FS at L5–S1 was associated with more aggravated sagittal balance in terms of smaller preoperative disc height, larger sagittal vertical axis, smaller lumbar lordosis, and larger pelvic incidence–lumbar lordosis mismatch. Patients with L5−S1 FS also had poorer clinical outcomes including back pain and ODI score after L4−5 PLIF. Patients with L5−S1 FS need to be carefully examined before L4−5 fusion considering their adverse outcomes due to underlying degenerative changes.

Evaluation of segmental mobility in patients with lumbar spondylolisthesis : A comparison of images from standing flexion-extension and standing/supine slippage

To evaluate segmental mobility with degenerative lumbar spondylolisthesis (DLS), upright lateral flexion-extension radiographs (FE) are widely used. However, some authors have described that a combination of lateral radiographs in the standing position and supine sagittal image (SS) reveal more segmental mobility than FE. The purpose of this study was to investigate the optimal method for evaluating segmental mobility with DLS.We included 92 consecutive Japanese patients diagnosed with DLS. Sagittal translation (ST) determined by FE and SS were compared. Pathological instability was defined as ST more than 8% of the upper vertebra. Patients were divided into those diagnosed with pathological instability in FE (PI-FE) and those diagnosed with SS (PI-SS), and lumbar lordosis (LL) in the standing position in each group were compared.ST in FE was significantly greater than in SS. Of 92 patients, 31 had pathological instability in FE or SS ; 17 patients had PI-FE, and 10 patients had PI-SS. LL in the standing position in PI-FE was significantly smaller than in PI-SS.ST in FE was greater than that in SS, contrary to previous studies' reports on Caucasians. Since Japanese individuals have smaller LL than Caucasians, FE tends to reveal more segmental mobility than SS. J. Med. Invest. 70 : 135-139, February, 2023.

Effect of Spinal Alignment Changes on Lower Back Pain in Patients Treated with Total Hip Arthroplasty for Hip Osteoarthritis.

Background and objectives: The influence of changes in spinal alignment after total hip arthroplasty (THA) on improvement in lower back pain (LBP) remains controversial. To evaluate how changes in spinal malalignment correlate with improvement in preoperative LBP in patients who underwent THA for hip osteoarthritis. Materials and Methods: From November 2015 to January 2017, 104 consecutive patients who underwent unilateral THA were prospectively registered. Whole spine X-rays and patient-reported outcomes (PROs) were obtained preoperatively and 12 months postoperatively. The PROs used were the Numerical Rating Scale (NRS) for back pain, EuroQol 5 Dimension, and Short Form-12. Results: Seventy-four (71%) patients with complete data were eligible for the analysis. The sagittal parameters changed slightly but significantly. Coronal alignment significantly improved. Twenty-six (37%) patients had LBP preoperatively. These patients had smaller lumbar lordosis (LL), larger PT, and larger PI minus LL than the patients without LBP. Fourteen (54%) of the 26 patients with preoperative LBP showed pain improvement, but there were no significant differences in the radiographic parameters. Conclusions: Although preoperative LBP was likely to be resolved after THA, there were no significant correlations between alignment changes and LBP improvement. The cause of LBP in patients with hip osteoarthritis (OA) patients might be multifactorial.

Association Between Vertebral Rotatory Subluxation and the Apical Vertebra in Degenerative Lumbar Scoliosis

To identify the apical vertebra is relate to the occurrence of vertebral rotatory subluxation (VRS) in degenerative lumbar scoliosis. In total, 86 patients with degenerative lumbar scoliosis included in this retrospective study were divided into 2 groups: with VRS and without VRS. Coronal and sagittal parameters were measured on whole-spine anteroposterior and lateral radiographs. The impact of VRS on the spine and pelvis parameters was statistically analyzed, and the correlation between the occurrence of VRS and the apical vertebra was analyzed by using logistic regression. VRS was present in 49 patients with degenerative lumbar scoliosis and absent in 37 patients. Compared with the patients without VRS, the patients with VRS had a smaller lumbar lordosis and thoracic kyphosis (P < 0.05) and a larger apical vertebra translation, apical vertebra tilt angle, Cobb angle, and pelvic incidence-lumbar lordosis (P < 0.05). Logistic regression analysis showed that apical vertebra translation and apical vertebra tilt angle were risk factors for the occurrence of VRS. The receiver operating characteristic curve analysis showed that apical vertebra translation greater than 23.2 mm and apical vertebra tilt angle greater than 11.8° were related to a greater probability of VRS in patients with degenerative lumbar scoliosis. VRS is an important characteristic to consider in degenerative lumbar scoliosis that can affect the coronal and sagittal alignment. The apical vertebra is correlated with the occurrence of VRS; an apical vertebra translation greater than 23.2 mm and apical vertebra tilt angle greater than 11.8° are highly correlate with the occurrence of VRS.

Predictors for quality of life improvement after surgery for degenerative cervical myelopathy: a prospective multi-center study

BackgroundDegenerative cervical myelopathy (DCM) can significantly impair a patient’s quality of life (QOL). In this study, we aimed to identify predictors associated with QOL improvement after surgery for DCM.MethodsThis study included 148 patients who underwent surgery for DCM. The European QOL-5 Dimension (EQ-5D) score, the Japanese Orthopedic Association for the assessment of cervical myelopathy (C-JOA) score, and the Nurick grade were used as outcome measures. Radiographic examinations were performed at enrollment. The associations of baseline variables with changes in EQ-5D scores from preoperative to 1-year postoperative assessment were investigated using a multivariable linear regression model.ResultsThe EQ-5D and C-JOA scores and the Nurick grade improved after surgery (P < 0.001, P < 0.001, and P < 0.001, respectively). Univariable analysis revealed that preoperative EQ-5D and C-JOA scores were significantly associated with increased EQ-5D scores from preoperative assessment to 1 year after surgery (P < 0.0001 and P = 0.045). Multivariable regression analysis showed that the independent preoperative predictors of change in QOL were lumbar lordosis (LL), sacral slope (SS), and T1 pelvic angle (TPA). According to the prediction model, the increased EQ-5D score from preoperatively to 1 year after surgery = 0.308 − 0.493 × EQ-5D + 0.006 × LL − 0.008 × SS + 0.004 × TPA.ConclusionsPreoperative LL, SS, and TPA significantly impacted the QOL of patients who underwent surgery for DCM. Less improvement in QOL after surgery was achieved in patients with smaller LL and TPA and larger SS values. Patients with these risk factors may therefore require additional support to experience adequate improvement in QOL.

Risk Factors for Recurrent L4-5 Disc Herniation After Percutaneous Endoscopic Transforaminal Discectomy: A Retrospective Analysis of 654 Cases.

BackgroundPercutaneous endoscopic lumbar discectomy (PELD) is an increasingly applied minimally invasive procedure that has several advantages in the treatment of lumbar disc herniation (LDH). However, recurrent LDH (rLDH) has become a concerning postoperative complication. It remains difficult to establish a consensus and draw reliable conclusions regarding the risk factors for rLDH.PurposeThis retrospective study aimed to investigate the risk factors associated with rLDH at the L4-5 level after percutaneous endoscopic transforaminal discectomy (PETD).MethodsA total of 654 patients who underwent the PETD procedure at the L4-5 level from October 2013 to January 2020 were divided into a recurrence (R) group (n=46) and a nonrecurrence (N) group (n=608). Demographic and clinical data and imaging parameters were collected and analyzed using univariate and multiple regression analyses.ResultsThe current study found a 7% rate of rLDH at the L4/5 level after successful PETD. Univariate analysis showed that older age, high BMI, diabetes mellitus history, smoking, large physical load intensity, moderate disc degeneration, small muscle–disc ratio (M/D), more fat infiltration, large sagittal range of motion (sROM), scoliosis, small disc height index (DHI), small intervertebral space angle (ISA), and small lumbar lordosis (LL) were potential risk factors (P < 0.10) for LDH recurrence after PETD at the L4-5 level. Multivariate analysis suggested that high BMI, large physical load intensity, moderate disc degeneration, small M/D, more fat infiltration, large sROM, small ISA, and small LL were independent significant risk factors for recurrence of LDH after PETD.ConclusionConsideration of disc degeneration, M/D, fat infiltration of the paravertebral muscles, sROM, ISA, LL, BMI, and physical load intensity prior to surgical intervention may contribute to the prevention of rLDH following PETD and lead to a more satisfactory operative outcome and the development of a reasonable rehabilitation program after discharge.

Acute effects of varying squat depths on lumbar intervertebral disks during high-load barbell back squat exercise.

We aimed to evaluate the acute physiological effects of high-load barbell back squat exercise on each lumbar intervertebral disk with varying squat depths. Thirteen subjects (age, 23.3±3.5 years) performed parallel and half-squat exercises (80% of one repetition maximum, eight repetitions, five sets) using a Smith machine. Sagittal magnetic resonance diffusion-weighted and spin-echo images of lumbar intervertebral disks were obtained by using a 1.5-Tesla MR system before and after each squat exercise; apparent diffusion coefficient (ADC; an index of water movement) and T2 relaxation time (an index of water content level) of the nucleus pulposus were calculated at all lumbar intervertebral disks. Additionally, we measured the angles of lumbar lordosis and anterior pelvic tilt at the bottom position of each squat using a three-dimensional motion-capture system. The nucleus pulposus of L4/5 (-5.0%, P<.01) and L5/S1 (-6.6%, P<.01) intervertebral disks showed decreased ADC values after parallel squat exercise. Moreover, post-exercise ADC value in parallel squat exercise was lower than that in half-squat exercise at L5/S1 intervertebral disk (P<.05). In contrast, the nucleus pulposus of all lumbar intervertebral disks had no significant T2 change before and after both squat exercises. The angles of lumbar lordosis (P<.01) and anterior pelvic tilt (P<.01) were smaller in parallel squat than in half-squat. Lower lumbar intervertebral disks are subject to greater mechanical stress during high-load parallel back squat exercise, which may result from smaller lumbar lordosis and anterior pelvic tilt angles at the bottom position during parallel squat.

Limitations of posterior spinal fusion to L5 for flaccid neuromuscular scoliosis focusing on pelvic obliquity.

Retrospective comparison based on the degree of pelvic obliquity (PO). To assess the controversial indications for and limitations of ending the instrumentation for posterior spinal fusion (PSF) at L5 in patients with flaccid neuromuscular scoliosis (fNMS). We reviewed the cases of 45 patients with progressive spinal deformity as a result of fNMS treated by PSF to L5 and followed for an average of 4years postoperatively with adequate clinical and radiological data. Anterior-posterior and lateral whole spine radiographs were evaluated. We divided patients into two groups based on the degree of pelvic obliquity (PO) at the final follow-up. Radiographic data from the two groups were analyzed to identify the indications and limitations of this surgical method focusing on PO. Preoperatively, there were significant differences between the two groups in Cobb angle, PO, thoracolumbar kyphosis, and lumbar lordosis (LL) while sitting; Cobb angle and LL while supine (Supine Cobb, and Supine LL); and major curve flexibility. Multivariate logistic regression analysis identified Supine Cobb and Supine LL as independent risk factors for residual PO at the final follow-up (Supine Cobb: odds ratio, 1.1; 95% confidence interval 1.0-1.2, Supine LL: odds ratio, 0.9; 95% confidence interval 0.8-1.0). Patients with larger preoperative Cobb angle and smaller LL while supine may not achieve adequate spine and pelvic correction and this may lead to deterioration in the PO over time, even after spinal fusion ending at L5.

Patients with Modic type 2 change have a severe radiographic representation in the process of lumbar degeneration: a retrospective imaging study

BackgroundThere are few studies to investigate changes in imaging parameters of Modic changes (MCs). The imaging studies examining the distinctions in the lumbar sagittal parameters between MCs and lumbar disc degeneration (LDD) are still lacking. The purpose of this study was to identify the differences in the lumbar sagittal parameters among patients for LDD with/without Modic type 2 change (MII).MethodsA total of 208 patients with lumbar degenerative disease from January 2017 to August 2018 volunteered for this study. Sixty-two patients with MII were used as the MC group. The other 146 patients served as the disc degeneration (DD) group. The DD scores and sagittal parameters were measured on magnetic resonance imaging (MRI) and X-ray by using Surgimap software.ResultsThe prevalence of MII for patients with degenerative lumbar diseases in this study was 29.81%, primarily located at L5/S1. There were significant differences in lumbar lordosis (LL) and sacral slope (SS) between these two groups (P < 0.05). Similarly, the significant decrease in intervertebral height index (IHI) was found at L3-S1 in the MC group, compared with the DD group (P < 0.05). However, a significant difference in intervertebral angle (IVA) was observed only at L5/S1 (P < 0.05). The MC group had the smaller endplate concave angle (ECA) than the DD group from L3 caudal endplate to S1 cranial endplate (P < 0.05).ConclusionsMII has a severe radiographic representation in the process of lumbar degeneration than patients without MII, and the overconcentration of load caused by the smaller LL, SS, and IVA may be a reasonable explanation to answer why MCs are more common at the L5/S1.

Lumbar Retrolisthesis Compensates Spinal Kyphosis

Study DesignLarge cohort study. ObjectiveTo investigate the role of lumbar retrolisthesis in spinopelvic alignment and health-related quality of life (HRQOL) among volunteers aged >50 years. Summary of Background DataLumbar retrolisthesis pathology has not been sufficiently elucidated. MethodsWe included 639 volunteers (257 men, average age 73 [50-92] years). Sagittal vertical axis (SVA), maximum thoracic kyphosis (maxTK), lumbar lordosis (LL), pelvic incidence (PI), and pelvic tilt (PT) were measured using whole-spine and pelvic radiographs taken in standing position. MaxTK was measured from the upper to the lower end vertebrae of spinal kyphosis in the sagittal plane using Cobb's method. HRQOL was evaluated using the Oswestry Disability Index (ODI). Subjects with ≥3 mm posterior lumbar vertebral slip and those with multiple retrolisthesis were included in R(+) and multiple groups, respectively. In single lumbar retrolisthesis subjects, those above L3–L4 were defined as the superior group and below L4–L5 as the inferior group. ResultsThe R(+) group had 259 (41%) subjects. Of the posterior slipped vertebrae, 235 (91%) were consistent with the lower end vertebra of the maxTK or its adjacent one. The R(+) group had significantly more males; subjects were older than those in the R(–) group. They also had significantly greater SVA, TK, maxTK, and PI-LL and smaller LL and PI. Multivariate analysis revealed that sex, maxTK, and LL were independent predictors of lumbar retrolisthesis. The inferior group had a significantly greater SVA, PT and PI-LL, and smaller LL and PI than the R(–), superior, and multiple groups. The inferior group also had significantly worse ODI than the R(–) group. ConclusionsSubjects with lumbar retrolisthesis showed greater spinal kyphosis and worse spinopelvic alignments. Subjects with lower-generated lumbar retrolisthesis showed worse spinopelvic alignment and HRQOL than subjects with upper-generated lumbar retrolisthesis and multiple ones and those without it. Level of EvidenceLevel IV.

Ethnic Variations in Radiographic Parameters and SRS-22 Scores in Adult Spinal Deformity: A Comparison Between North American and Japanese Patients Above 50 Years of Age With Minimum 2-Year Follow-up.

Retrospective review of North American and Japanese adult spinal deformity (ASD) database. To investigate the ethnical differences in radiographic parameters and Scoliosis Research Society (SRS)-22 between North American and Japanese ASD. Previous comparison study between North American and Japanese ASD patients has revealed Japanese patients had marked pelvic tilt deformity and had lower Oswestry Disability Index scores corresponding to established thresholds of radiographic deformity. However, the subjects of the previous study included relatively younger ASD patients (above 18 y) of idiopathic origin. Total 282 ASD patients older than 50 years, 211 patients from North America (United States) and 71 patients from Japan (JP), with minimum 2-year follow-up postoperatively were included in the study. Radiologic parameters were compared at the baseline and at 2-year follow-up. SRS-22 score was used for the comparison of clinical outcome. At baseline, Japan showed significantly worse sagittal alignment such as smaller lumbar lordosis (LL), larger pelvic incidence (PI), and larger sagittal vertical axis than United States. However, Japan had significantly fewer levels fused than United States (US, 12.66±4.6; JP, 8.49±2.7). At 2 years after the surgery, Japan still had significantly worse residual sagittal deformity. Comparison of SRS-22 scores revealed Japan had better pain but worse functional domain scores at baseline which improved to comparable levels to the United States at 2 years. Self-image and mental health scores in Japan were significantly worse both at baseline and at 2 years. Analysis of factors affecting SRS-22 satisfaction score at 2 years revealed that previous spinal fusion surgery in the United States and LL, PI-LL, and sagittal vertical axis at 2 years in Japan had significant correlation. These similarities and discrepancies may be influenced by the cultural or lifestyle differences between both nations and should be considered when interpreting the results of ASD studies among different ethnicities.

Spontaneous Improvement of Compensatory Knee Flexion After Surgical Correction of Mismatch Between Pelvic Incidence and Lumbar Lordosis.

A retrospective study. The aim of this study was to investigate the correlation between pelvic incidence (PI) and lumbar lordosis (LL) mismatch and knee flexion during standing in patients with lumbar degenerative diseases and to examine the effects of surgical correction of the PI-LL mismatch on knee flexion. Only several studies focused on knee flexion as a compensatory mechanism of the PI-LL mismatch. Little information is currently available on the effects of lumbar correction on knee flexion in patients with the PI-LL mismatch. A group of patients with lumbar degenerative diseases were divided into PI-LL match group (PI-LL ≤ 10°) and PI-LL mismatch group (PI-LL > 10°). A series of radiographic parameters and knee flexion angle (KFA) were compared between the two groups. The PI-LL mismatch group was further subdivided into operative and nonoperative group. The changes in KFA with PI-LL were examined. The PI-LL mismatch group exhibited significantly greater sagittal vertical axis (SVA), pelvic tilt (PT) and KFA, and smaller LL, thoracic kyphosis (TK), and sacral slope than the PI-LL match group. PI-LL, LL, PI, SVA, and PT were significantly correlated with KFA in the PI-LL mismatch group. From baseline to 6-month follow-up, all variables were significantly different in the operative group with the exception of PI, although there was no significant difference in any variable in the nonoperative group. The magnitude of surgical correction in the PI-LL mismatch was significantly correlated with the degree of spontaneous changes in KFA, PT, and TK. The PI-LL mismatch would contribute to compensatory knee flexion during standing in patients with lumbar degenerative disease. Surgical correction of the PI-LL mismatch could lead to a spontaneous improvement of compensatory knee flexion. The degree of improvement in knee flexion depends in part on the amount of correction in the PI-LL mismatch. 3.

Role of pelvic translation and lower-extremity compensation to maintain gravity line position in spinal deformity

Previous forceplate studies analyzing the impact of sagittal-plane spinal deformity on pelvic parameters have demonstrated the compensatory mechanisms of pelvis translation in addition to rotation. However, the mechanisms recruited for this pelvic rotation were not assessed. This study aims to analyze the relationship between spinopelvic and lower-extremity parameters and clarify the role of pelvic translation. This is a retrospective study of patients with spinal deformity and full-body EOS images. Patients with only stenosis or low-back pain were excluded. Patients were grouped according to T-1 spinopelvic inclination (T1SPi): sagittal forward (forward, > 0.5°), neutral (-6.3° to 0.5°), or backward (< -6.3°). Pelvic translation was quantified by pelvic shift (sagittal offset between the posterosuperior corner of the sacrum and anterior cortex of the distal tibia), hip extension was measured using the sacrofemoral angle (SFA; the angle formed by the middle of the sacral endplate and the bicoxofemoral axis and the line between the bicoxofemoral axis and the femoral axis), and chin-brow vertical angle (CBVA). Univariate and multivariate analyses were used to compare the parameters and correlation with the Oswestry Disability Index (ODI). In total, 336 patients (71% female; mean age 57 years; mean body mass index 27 kg/m(2)) had mean T1SPi values of -8.8°, -3.5°, and 5.9° in the backward, neutral, and forward groups, respectively. There were significant differences in the lower-extremity and spinopelvic parameters between T1SPi groups. The backward group had a normal lumbar lordosis (LL), negative SVA and pelvic shift, and the largest hip extension. Forward patients had a small LL and an increased SVA, with a large pelvic shift creating compensatory knee flexion. Significant correlations existed between lower-limb parameter and pelvic shift, pelvic tilt, T-1 pelvic angle, T1SPi, and sagittal vertical axis (0.3 < r < 0.8; p < 0.001). ODI was significantly correlated with knee flexion and pelvic shift. This is the first study to describe full-body alignment in a large population of patients with spinal pathologies. Furthermore, patients categorized based on T1SPi were found to have significant differences in the pelvic shift and lower-limb compensatory mechanisms. Correlations between lower-limb angles, pelvic shift, and ODI were identified. These differences in compensatory mechanisms should be considered when evaluating and planning surgical intervention for adult patients with spinal deformity.

Radiological improvements in global sagittal alignment after lumbar decompression without fusion.

A retrospective, radiographical study. To evaluate short-term radiological changes in sagittal alignment after lumbar decompression without fusion for lumbar canal stenosis. Although the importance of global sagittal balance is underscored recently, little is known about the changes in sagittal alignment after lumbar canal decompression. We retrospectively reviewed 88 patients who underwent lumbar decompression without fusion at a single institution between November 2008 and May 2013, with a minimum follow-up of 5 months. Standing radiographs at the preoperative period and the final follow-up were assessed. Radiological parameters included the sagittal vertical axis (SVA), lumbar lordosis (LL), pelvic tilt, pelvic incidence (PI), occipital 7th cervical angle, and thoracic kyphosis, which were measured by 2 spine surgeons. The Zurich Claudication Questionnaire and visual analogue scale scores were obtained to assess the patient-based clinical outcomes. Both LL and thoracic kyphosis significantly increased postoperatively, whereas SVA, PI-LL (PI minus LL), and pelvic tilt significantly decreased (P<0.05). There were no significant differences between the preoperative and postoperative occipital 7th cervical angle and PI. The amount of increment in LL was greater in patients with small preoperative LL. The improvement in SVA was greater in those with a large preoperative SVA. The Zurich Claudication Questionnaire and visual analogue scale scores showed no significant correlation with the radiological parameters. Lumbar decompression without fusion can induce a reactive improvement in the lumbar and global sagittal alignment even if a sagittal imbalance exists preoperatively. 4.

Discordance of gravity line and C7PL in patient with adult spinal deformity—factors affecting the occiput-trunk sagittal discordance

Background contextDuring quiet standing, the gravity line (GL) can be located according to the sum of the ground reaction forces (GRFs) measured with a force platform. C7 plumb line (C7PL) is an easy method to estimate sagittal trunk balance, but discordance between C7PL and the GL is widely recognized. However, the prevalence of occiput-trunk (O-T) discordance (GL-C7PL>3 cm) and the factors affecting this type of discordance have not yet been determined. PurposeThe purpose of this study was to report the prevalence of O-T discordance in adult spinal deformity (ASD) patients and identify the factors affecting this type of discordance. Study designThis was a retrospective consecutive case series of ASD. Patient sampleThis retrospective case series included 300 consecutive ASD patients. The inclusion criteria were age more than 50 years, Cobb angle of the main curve more than 20°, and C7PL more than 5 cm. The exclusion criteria consisted of inappropriate radiography; syndromic, neuromuscular, or other pathologic conditions; and previous joint replacement. Outcome measuresThe outcome measures included self-reported (Scoliosis Research Society 22 and Oswestry disability index [ODI]) and radiographic measures. MethodsIn a retrospective consecutive case series, demographic and radiographic patient data were reviewed. Demographic data included age, gender, curve type, SRS22, and ODI. Radiographic data included GL, C7PL, C2–C7, T2–T5, T5–T12, T10–L2, T2 tilt, lumbar lordosis (LL), sacrum slope (SS), pelvic tilt (PT), and pelvic incidence (PI). Global sagittal and spinopelvic alignments were also reviewed. Patients were categorized in either a O-T concordance (C group, GL-C7PL<3 cm) or a O-T discordance (D group, GL-C7PL more than +3 cm) group, and the demographic, radiographic, and clinical outcome data were compared between these groups. One-way analysis of variance, correlation coefficient tests, and multiple regression and logistic regression analyses were performed for statistical analysis. p Value less than .01 was considered statistically significant. Force platform analysis was performed to assess the relationship among GRF, GL, and C7PL. ResultsAmong 300 consecutive ASD patients, 72 (24%) were categorized in the D group. There was no significant difference in terms of demographic data between the C and D groups. The SRS and ODI of patients with GL more than 10 cm were significantly lower than those of patients with GL less than 10 cm. Comparisons of regional sagittal alignment showed significantly higher T5–T12 values in the D group, and multiple regression analysis revealed significant correlations among T2–T5, T5–T12, and GL-C7PL. In contrast, the analysis of global sagittal alignment revealed a significantly large T2 sagittal tilt in the D group compared with the C group. Force platform analysis showed concordance between GRF and GL, whereas discordance was observed between GRF and C7PL. The D group could be classified into 2 groups based on the global sagittal alignment: 10 patients were classified as the hypo-compensation type (small SVA, small CL, small TK, and normal-to-small LL), whereas 62 were classified as the forward-leaning type (large sagittal vertical axis, large cervical lordosis, large thoracic kyphosis, and small LL). ConclusionsThe prevalence of discordance between GL and C7PL in ASD patients was 24%, and thoracic kyphosis and global sagittal alignment were significantly correlated with this discordance. The concordance of GRF and GL and the discordance of GRF and C7PL highlight the importance and necessity of accounting for GL when considering surgical treatment.

Sagittal spino-pelvic alignment failures following three column thoracic osteotomy for adult spinal deformity

Three column thoracic osteotomy (TCTO) is effective to correct rigid thoracic deformities, however, reasons for residual postoperative spinal deformity are poorly defined. Our objective was to evaluate risk factors for poor spino-pelvic alignment (SPA) following TCTO for adult spinal deformity (ASD). Multicenter, retrospective radiographic analysis of ASD patients treated with TCTO. Radiographic measures included: correction at the osteotomy site, thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic tilt (PT), and pelvic incidence (PI). Final SVA and PT were assessed to determine if ideal SPA (SVA<4cm, PT<25°) was achieved. Differences between the ideal (IDEAL) and failed (FAIL) SPA groups were evaluated. A total of 41 consecutive ASD patients treated with TCTO were evaluated. TCTO significantly decreased TK, maximum coronal Cobb angle, SVA and PT (P<0.05). Ideal SPA was achieved in 32 (78%) and failed in 9 (22%) patients. The IDEAL and FAIL groups had similar total fusion levels and similar focal, SVA and PT correction (P>0.05). FAIL group had larger pre- and post-operative SVA, PT and PI and a smaller LL than IDEAL (P<0.05). Poor SPA occurred in 22% of TCTO patients despite similar operative procedures and deformity correction as patients in the IDEAL group. Greater pre-operative PT and SVA predicted failed post-operative SPA. Alternative or additional correction procedures should be considered when planning TCTO for patients with large sagittal global malalignment, otherwise patients are at risk for suboptimal correction and poor outcomes.

The influence of thoracic kyphosis on sagittal balance of the lumbosacral spine in thoracic idiopathic scoliosis patients

To evaluate the influence of thoracic kyphosis to sagittal alignment and balance of the lumbosacral vertebrae in thoracic adolescent idiopathic scoliosis patients. Standing posteroanterior and lateral x-rays of a cohort of 55 patients with thoracic adolescent idiopathic scoliosis were obtained. The patients were classified according to their thoracic kyphosis, the first group TK < 10 degrees and the second group 10 degrees < or = TK < or = 40 degrees . The following parameters were measured: lumbar lordosis (LL), upper and lower arc of lumbar lordosis, sagittal vertical axis, sacral slope (SS), pelvic incidence (PI), pelvic tilt (PT). Sagittal plane parameters were analyzed using t-test between two groups, with significance set at P < 0.05. Linear correlations between parameters were calculated using Pearson correlation coefficients, with significance set at P < 0.01. There were smaller LL and upper arc of lumbar lordosis in the first group. Significant linear correlations were found between each single adjacent shape parameter. Significant correlations were also found between TK, LL and upper arc of lumbar lordosis, as well as between PT, SS and PI. Sagittal alignment and balance of the lumbosacral vertebrae may influence the thoracic kyphosis in AIS patients. The mechanism of this influence may through the adaptation of upper arc of lumbar lordosis. This influence must be considered in thoracic adolescent idiopathic scoliosis patients who undergo selective posterior thoracic fusion.