Moderate Degeneration of the Lumbar Paravertebral Muscle in Patients With Dynamic Sagittal Imbalance,A retrospective cohort study

2020 ◽  
Author(s):  
Nan Ru ◽  
Guodong Wang ◽  
Yang Li ◽  
Xingang Cui ◽  
Jianmin Sun
Keyword(s):  
Retrospective Cohort ◽  
Lumbar Lordosis ◽  
Vertical Axis ◽  
Erector Spinae ◽  
Sagittal Imbalance ◽  
Mineral Density ◽  
Sagittal Vertical Axis ◽  
Cross Sectional ◽  
Paravertebral Muscle ◽  
Pelvic Parameters

Abstract Study Design: A retrospective cohort study.Background: Sagittal imbalance of the spine is a comprehensive concept and can be caused by many causes. Paravertebral muscle is an important factor in the stabilization of spine.The active subsystem formed by the muscles around the lumbar spine plays an important role in maintaining lumbar spine stability and extendding the spine . Clinically, we found that some patients showed spinal sagittal balance when they were energetic, but hunched or leaning forward after a period of walking or working.Standing full-spine lateral digital radiographs shows increased sagittal vertical axis (SVA)dynamically.We call this symptoms a dynamic sagittal imbalance（DSI. However, the sagittal sequence, paravertebral muscle changes, and the correlation between them in DSI patients have not been clearly explored. The purpose of this study was to investigate the changes of spinal-pelvic parameters; paravertebral muscle; and the relationship between the two in DSI patients .Method: The study group comprised 31 patients with DSI and 42 control patients.All subjects underwent radiologic whole spine X-ray examination and lumbar MRI( Magnetic Resonance Imaging) scanning. Spinal-pelvic parameters such as sagittal vertical axis (SVA), thoracic kyphosis (TK), thoracolumbar kyphosis (TLK), lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT) and pelvic incidence (PI) was measured. The cross-sectional areas （CSA）of the erector spinae (ES),multifidus (MF), and vertebral body were measured at L2/L3 and L4/L5. The fat infiltration (FI) and relative cross-sectional area (RCSA)of muscle of these muscles were quantitatively measured though Image J. All subjects were examined for bone mineral density and pulmonary function to test the overall skeletal muscle capacity.Result: Compared with the control group,the DSI group had a smaller lumbar lordosis，more severe fat infiltration and lower Relative functional cross-sectional area(RFCSA) of paravertebral muscle ES(erector spinae)&MF(multifidus). There was no correlation between muscle degeneration and spinal-pelvic parameters in DSI patients.In addition,There were no statistically significant differences in bone mineral density test and pulmonary function test which reflected systemic skeletal muscle capacity of whole body.Conclusion: DSI，along with moderate degeneration of the paravertebral muscles of the lumbar spine.Usually accompanied by a reduction in lumbar lordosis. DSI is regards as the pre-state of PDSI.

scholarly journals Degeneration of the Lumbar Paravertebral Muscle in Patients With Dynamic Sagittal Imbalance, A Retrospective Cohort Study

2020 ◽  
Author(s):  
Nan Ru ◽  
Yang Li ◽  
Xingang Cui ◽  
Jianmin Sun ◽  
Guodong Wang
Keyword(s):  
Retrospective Cohort ◽  
Vertical Axis ◽  
Erector Spinae ◽  
Control Group ◽  
Sagittal Imbalance ◽  
Muscle Degeneration ◽  
Sagittal Vertical Axis ◽  
Cross Sectional ◽  
Paravertebral Muscle ◽  
Paravertebral Muscles

Abstract Study Design: A retrospective cohort study.Background: Sagittal imbalance of the spine is a comprehensive concept ..In appearance, it is often manifested as body leaning forward instability; whereas on standing full-spine lateral digital radiographs, it shows an increased sagittal vertical axis (SVA) .Clinically, we found that some patients showed normal sagittal balance at initiation, but hunched or leaned forward after a period of walk or activity. This condition is called dynamic sagittal imbalance(DSI). There is no systematic study to explore the paravertebral muscles changes of dynamic sagittal imbalance.Method: The study group comprised 31 DSI patients and 42 control patients. All subjects underwent radiologic whole spine X-ray examination and lumbar MRI( Magnetic Resonance Imaging) scanning. Spinal-pelvic parameters at initiation such as sagittal vertical axis (SVA), thoracic kyphosis (TK), thoracolumbar kyphosis (TLK), lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT) and pelvic incidence (PI) was measured. The cross-sectional areas CSA of the erector spinae (ES), multifidus (MF), and vertebral body area were measured at L2/L3 and L4/L5. The fat infiltration (FI) and relative cross-sectional area (RCSA)of muscle of these above muscles were quantitatively measured though Image J softwore.Result : Compared with the control group, the DSI group had a smaller lumbar lordosis, more severe fat infiltration and lower relative functional cross-sectional area(RFCSA) of paravertebral muscle (erector spinae and multifidus) . In DSI group, the point-in-time of occurrence of dynamic sagittal imbalance was statistically correlated with degeneration of paravertbral muscles at L4/L5 level, whereas no correlation between the two above at L2/L3 level.Conclusion: In conclusion, DSI an normal SVA (SVA＜40mm) at initiation, and prominent increase in SVA after activity with thunks marked inclined. Paravertebral muscle degeneration plays an important role in the DSI process, Patients in the DSI group had more severe paravertebral muscle degeneration compared with patients in control group. There was a significant correlation between the severity of DSI symptoms and the degeneration of lower lumbar paravertebral muscles. These findings may help spinal surgeons better understand sagittal balance of spine.

scholarly journals Effect of sagittal imbalance on functional disability in patients with degenerative spondylolisthesis

2019 ◽  
Vol 6 (1) ◽  
pp. 31
Author(s):  
Ramdas Maloth
Keyword(s):  
Functional Disability ◽  
Pelvic Incidence ◽  
Sagittal Plane ◽  
Degenerative Spondylolisthesis ◽  
Vertical Axis ◽  
P Value ◽  
Sagittal Imbalance ◽  
Sagittal Vertical Axis ◽  
Cross Sectional ◽  
Digital Radiograph

<p class="abstract"><strong>Background:</strong> Deformity of spine in sagittal plane is a major cause of pain and disability among patients presenting with low back pain to spine clinic. We have studied the effect of spinal sagittal imbalance on functional disability in these patients.</p><p class="abstract"><strong>Methods:</strong> Cross sectional observational study in 50 patients with degenerative spondylolisthesis of more than 45 years age group study done in period of1 years. Subjects underwent standing lateral radiographs of the spine in a relaxed position, facing forward, with their knees maximally extended and their arms raised horizontally forward resting on a support. 2 radiographic films are stitched at baseline using digital radiograph operating console (DROC) software.</p><p class="abstract"><strong>Results: </strong>In our study out of 50 patients we observed female preponderance, female:male 3:1, degenerative spondylolisthesis more commonly involves L4-L5 level (46 patients). 58% of patients with severe degenerative spondylolisthesis. There is significant correlation between sagittal vertical axis (SVA) and severity (p=0.015) in both grade 1 and grade 2 DS, there is significant correlation between pi and functional disability (p=0.001 and 0.010 respectively) it is found that pelvic tilt with p=0.02 and sagittal vertical axis with p value 0.036 are the two most significant variables at the end of backward elimination analysis.</p><p class="abstract"><strong>Conclusions:</strong> Sagittal imbalance is seen in degenerative spondylolisthesis which needs further evaluation with spinopelvic parameters. Pelvic incidence and sagittal vertebral axis are important determinants of functional disability in patients with degenerative spondylolisthesis. Individuals with high pelvic incidence and more lumbo pelvic kyphosis showed more functional disability compared to others.</p>

scholarly journals Pelvic retroversion: a compensatory mechanism for lumbar stenosis

2017 ◽  
Vol 27 (2) ◽  
pp. 137-144 ◽  
Author(s):  
Sina Pourtaheri ◽  
Akshay Sharma ◽  
Jason Savage ◽  
Iain Kalfas ◽  
Thomas E. Mroz ◽  
...  
Keyword(s):  
Lumbar Lordosis ◽  
Weight Bearing ◽  
Thoracolumbar Spine ◽  
Vertical Axis ◽  
Neurogenic Claudication ◽  
Sagittal Imbalance ◽  
Compensatory Mechanism ◽  
Lumbar Stenosis ◽  
Sagittal Vertical Axis ◽  
Fixed Sagittal Imbalance

OBJECTIVEThe flexed posture of the proximal (L1–3) or distal (L4–S1) lumbar spine increases the diameter of the spinal canal and neuroforamina and can relieve symptoms of neurogenic claudication. Distal lumbar flexion can result in pelvic retroversion; therefore, in cases of flexible sagittal imbalance, pelvic retroversion may be compensatory for lumbar stenosis and not solely compensatory for the sagittal imbalance as previously thought. The authors investigate underlying causes for pelvic retroversion in patients with flexible sagittal imbalance.METHODSOne hundred thirty-eight patients with sagittal imbalance who underwent a total of 148 fusion procedures of the thoracolumbar spine were identified from a prospective clinical database. Radiographic parameters were obtained from images preoperatively, intraoperatively, and at 6-month and 2-year follow-up. A cohort of 24 patients with flexible sagittal imbalance was identified and individually matched with a control cohort of 23 patients with fixed deformities. Flexible deformities were defined as a 10° change in lumbar lordosis between weight-bearing and non–weight-bearing images. Pelvic retroversion was quantified as the ratio of pelvic tilt (PT) to pelvic incidence (PI).RESULTSThe average difference between lumbar lordosis on supine MR images and standing radiographs was 15° in the flexible cohort. Sixty-eight percent of the patients in the flexible cohort were diagnosed preoperatively with lumbar stenosis compared with only 22% in the fixed sagittal imbalance cohort (p = 0.0032). There was no difference between the flexible and fixed cohorts with regard to C-2 sagittal vertical axis (SVA) (p = 0.95) or C-7 SVA (p = 0.43). When assessing for postural compensation by pelvic retroversion in the stenotic patients and nonstenotic patients, the PT/PI ratio was found to be significantly greater in the patients with stenosis (p = 0.019).CONCLUSIONSFor flexible sagittal imbalance, preoperative attention should be given to the root cause of the sagittal misalignment, which could be compensation for lumbar stenosis. Pelvic retroversion can be compensatory for both the lumbar stenosis as well as for sagittal imbalance.

scholarly journals Association between back muscle degeneration and spinal-pelvic parameters in patients with degenerative spinal kyphosis

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Weiwei Xia ◽  
Han Fu ◽  
Zhenqi Zhu ◽  
Chenjun Liu ◽  
Kaifeng Wang ◽  
...  
Keyword(s):  
Erector Spinae ◽  
Sacral Slope ◽  
Muscle Degeneration ◽  
Imaging Data ◽  
Spinal Level ◽  
Sagittal Vertical Axis ◽  
Cross Sectional ◽  
Pelvic Parameters ◽  
Lumbar Level ◽  
Psoas Muscles

Abstract Background The paraspinal and psoas muscles have been considered to be essentially important for stabilizing the spinal column, and the muscle degeneration was found to exist in degenerative spinal kyphosis (DSK) patients. However, it is still not clear the relationship between muscle degeneration and spinal-pelvic alignment. The purpose of this study was to determine the correlations between the individual muscle degeneration at each lumbar spinal level and spinal-pelvic parameters in DSK patients. Methods The imaging data of 32 patients with DSK were retrospectively analyzed. The fat infiltration (FI) and relative cross-sectional area of muscle (RCSA) were quantitatively measured for multifidus (MF), erector spinae (ES) and psoas (PS) at each spinal level from L1/2 to L5/S1. The correlations were analyzed between RCSA and the sagittal vertical axis (SVA), thoracic kyphosis (TK), thoracolumbar kyphosis (TLK), lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT) and pelvic incidence (PI). Results The FI of MF and ES at L3/4, L4/5 and L5/S1 were higher than that at L1/2 and L2/3. The FI of PS at L4/5 and L5/S1 were lower than that of L1/2, L2/3 and L3/4. The RCSA of ES and PS from L1/2 to L5/S1 gradually increased, whereas the RCSA of ES from L1/2 to S5/S1 gradually decreased. The RCSA of MF at the L1/2 level was negatively correlated SVA (r = − 0.397,p = 0.024); the RCSA at L3/4, L4/5 and L5/S1 levels were negatively correlated with TK (r = − 0.364, p = 0.04; r = − 0.38, p = 0.032; r = − 0.432, p = 0.014); the RCSA at L4/5 level was positively correlated with LL (r = 0.528, p = 0.002). The RCSA of ES at L3/4 and L4/5 levels were positively correlated with PI (r = 0.377, p = 0.037) and SS (r = 0.420, p = 0.019). Conclusions FI of MF and ES at lower lumbar level is higher than that at upper level, but FI of PS at upper lumbar level is higher than that at lower level. MF and ES have different roles for maintaining the sagittal spinal-pelvic balance.

scholarly journals Effectiveness of deformity-correction surgery for primary degenerative sagittal imbalance: a meta-analysis

2017 ◽  
Vol 27 (5) ◽  
pp. 540-551 ◽  
Author(s):  
Chang-Hyun Lee ◽  
Chun Kee Chung ◽  
Jee-Soo Jang ◽  
Sung-Min Kim ◽  
Dong-Kyu Chin ◽  
...  
Keyword(s):  
Lumbar Lordosis ◽  
Thoracic Kyphosis ◽  
Meta Analysis ◽  
Deformity Correction ◽  
Vertical Axis ◽  
Sagittal Imbalance ◽  
Kyphosis Angle ◽  
Sagittal Vertical Axis ◽  
Correction Surgery ◽  
The Mean

OBJECTIVEAs life expectancy continues to increase, primary degenerative sagittal imbalance (PDSI) is diagnosed in an increasing number of elderly people. Although corrective surgery for this sagittal deformity is becoming more popular, the effectiveness of the procedure remains unclear. The authors aimed to collate the available evidence on the effectiveness and complications of deformity-correction surgery in patients with PDSI.METHODSThe authors carried out a meta-analysis of clinical studies regarding deformity correction in patients with PDSI. The studies were identified through searches of the PubMed, Embase, Web of Science, and Cochrane databases. Surgery outcomes were evaluated and overall treatment effectiveness was assessed in terms of the minimum clinically important difference (MCID) in Oswestry Disability Index (ODI) values and pain levels according to visual analog scale (VAS) scores and in terms of restoration of spinopelvic parameters to within a normal range. Data are expressed as mean differences with 95% CIs.RESULTSTen studies comprising 327 patients were included. The VAS and ODI values improved after deformity-correction surgery. The smallest treatment effect exceeded the MCID for VAS values (4.15 [95% CI 3.48–4.82]) but not for ODI values (18.11 [95% CI 10.99–25.23]). At the final follow-up visit, the mean lumbar lordosis angle (−38.60° [95% CI −44.19° to −33.01°]), thoracic kyphosis angle (31.10° [95% CI 24.67°–37.53°]), C-7 sagittal vertical axis (65.00 mm [95% CI 35.27–94.72 mm]), and pelvic tilt angle (30.82° [95% CI 24.41°–37.23°]) remained outside their normal ranges. Meta-regression analyses revealed a significant effect of ODI change in relation to lumbar lordosis change (p = 0.004). After a mean of 2 years after deformity correction, the mean lumbar lordosis angle and C-7 sagittal vertical axis decreased by 5.82° and 38.91 mm, respectively, and the mean thoracic kyphosis angle increased by 4.7°. The incidences of proximal junctional kyphosis and pseudarthrosis were 23.7% and 12.8%, respectively.CONCLUSIONSDeformity correction substantially relieves back pain for about 2 years in adult patients with PDSI. Sufficient surgical restoration of lumbar lordosis can lead to substantial improvement in patient disability and reduced decompensation. Deformity correction represents a viable therapeutic option for patients with PDSI, but further technical advancements are necessary to achieve sufficient lumbar lordosis and reduce complication rates.

Underarm bracing for adolescent idiopathic scoliosis leads to flatback deformity

2019 ◽  
Vol 101-B (11) ◽  
pp. 1370-1378 ◽  
Author(s):  
Jason P. Y. Cheung ◽  
Christopher H. W. Chong ◽  
Prudence W. H. Cheung
Keyword(s):  
Quality Of Life ◽  
Lumbar Spine ◽  
Lumbar Lordosis ◽  
Thoracic Kyphosis ◽  
Pelvic Tilt ◽  
Vertical Axis ◽  
Sacral Slope ◽  
Sagittal Vertical Axis ◽  
Pelvic Parameters

Aims The aim of this study was to determine the influence of pelvic parameters on the tendency of patients with adolescent idiopathic scoliosis (AIS) to develop flatback deformity (thoracic hypokyphosis and lumbar hypolordosis) and its effect on quality-of-life outcomes. Patients and Methods This was a radiological study of 265 patients recruited for Boston bracing between December 2008 and December 2013. Posteroanterior and lateral radiographs were obtained before, immediately after, and two-years after completion of bracing. Measurements of coronal and sagittal Cobb angles, coronal balance, sagittal vertical axis, and pelvic parameters were made. The refined 22-item Scoliosis Research Society (SRS-22r) questionnaire was recorded. Association between independent factors and outcomes of postbracing ≥ 6° kyphotic changes in the thoracic spine and ≥ 6° lordotic changes in the lumbar spine were tested using likelihood ratio chi-squared test and univariable logistic regression. Multivariable logistic regression models were then generated for both outcomes with odds ratios (ORs), and with SRS-22r scores. Results Reduced T5-12 kyphosis (mean -4.3° (sd 8.2); p < 0.001), maximum thoracic kyphosis (mean -4.3° (sd 9.3); p < 0.001), and lumbar lordosis (mean -5.6° (sd 12.0); p < 0.001) were observed after bracing treatment. Increasing prebrace maximum kyphosis (OR 1.133) and lumbar lordosis (OR 0.92) was associated with postbracing hypokyphotic change. Prebrace sagittal vertical axis (OR 0.975), prebrace sacral slope (OR 1.127), prebrace pelvic tilt (OR 0.940), and change in maximum thoracic kyphosis (OR 0.878) were predictors for lumbar hypolordotic changes. There were no relationships between coronal deformity, thoracic kyphosis, or lumbar lordosis with SRS-22r scores. Conclusion Brace treatment leads to flatback deformity with thoracic hypokyphosis and lumbar hypolordosis. Changes in the thoracic spine are associated with similar changes in the lumbar spine. Increased sacral slope, reduced pelvic tilt, and pelvic incidence are associated with reduced lordosis in the lumbar spine after bracing. Nevertheless, these sagittal parameter changes do not appear to be associated with worse quality of life. Cite this article: Bone Joint J 2019;101-B:1370–1378.

scholarly journals The Pelvic Incidence Stratified Sagittal Spinopelvic Alignment in Asymptomatic Chinese Population With Different Age Groups

2021 ◽  
pp. 219256822198964
Author(s):  
Siyu Zhou ◽  
Zhuoran Sun ◽  
Wei Li ◽  
Da Zou ◽  
Weishi Li
Keyword(s):  
Chinese Population ◽  
Pelvic Incidence ◽  
Sagittal Alignment ◽  
Age Groups ◽  
Vertical Axis ◽  
Elderly Subjects ◽  
Sagittal Vertical Axis ◽  
Cross Sectional ◽  
Sagittal Parameters ◽  
Very High

Study Design: Cross-sectional study. Objective: To provide the age- and pelvic incidence-related variations of sagittal alignment in asymptomatic Chinese population. Methods: This study recruited asymptomatic adult subjects. All subjects undertook the standing whole spinal radiograph and the sagittal parameters were measured: sagittal vertical axis (SVA), T1 pelvic angle (TPA), lumbar lordosis (LL), thoracic kyphosis (TK), pelvic incidence (PI) and pelvic tilt (PT). All subjects were divided into young, middle aged and elderly groups, then each age group was further divided into 5 subgroups (very low, low, average, high and very high) based on PI values. The relations between PI, age and other parameters were evaluated. The differences in sagittal parameters of each PI subgroup were compared. Results: 546 subjects were included with an average age of 38.6 years (18 to 81). The number of subjects over 70 years and with very low PI was relatively small. The average of PI, TPA, PT and LL were 45.9° ± 8.4°, 6.4° ± 6.2°, 11.9° ± 6.6° and 49.2° ± 10.1°, respectively. SVA, TPA, TK and PT increased with age ( P < 0.05), while SVA, TPA, PT, PI-LL also increased with PI ( P < 0.05). LL, PT, TPA, PI-LL and LL-TK were different among the 5 PI subgroups ( P < 0.05). However, the values of LL in elderly subjects with high and very high PI were similar. Conclusion: The age- and PI-related variations in sagittal alignment of Chinese population were provided. The sagittal parameters were significantly influenced by age and PI. The individual pelvic morphology should be carefully considered during the assessment and restoration of sagittal balance.

scholarly journals Gender-specific analysis for the association between trunk muscle mass and spinal pathologies

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yusuke Hori ◽  
Masatoshi Hoshino ◽  
Kazuhide Inage ◽  
Masayuki Miyagi ◽  
Shinji Takahashi ◽  
...  
Keyword(s):  
Muscle Mass ◽  
Bioelectrical Impedance ◽  
Vertical Axis ◽  
Impedance Analysis ◽  
Poor Quality ◽  
Trunk Muscle ◽  
Sagittal Vertical Axis ◽  
Cross Sectional ◽  
Lower Trunk ◽  
Significant Difference

AbstractWe investigated the relationship between trunk muscle mass and spinal pathologies by gender. This multicenter cross-sectional study included patients aged ≥ 30 years who visited a spinal outpatient clinic. Trunk and appendicular muscle mass were measured using bioelectrical impedance analysis. The Oswestry Disability Index (ODI), visual analog scale (VAS) score for low back pain, sagittal vertical axis (SVA), and EuroQol 5 Dimension (EQ5D) score were investigated to evaluate spinal pathology. The association between trunk muscle mass and these parameters was analyzed by gender using a non-linear regression model adjusted for patients’ demographics. We investigated the association between age and trunk muscle mass. We included 781 men and 957 women. Trunk muscle mass differed significantly between men and women, although it decreased with age after age 70 in both genders. Lower trunk muscle mass was significantly associated with ODI, SVA, and EQ5D score deterioration in both genders; its association with VAS was significant only in men. Most parameters deteriorated when trunk muscle mass was < 26 kg in men and < 19 kg in women. Lower trunk muscle mass was associated with lumbar disability, spinal imbalance, and poor quality of life in both genders, with significant difference in muscle mass.

The utility of supine radiographs in the assessment of thoracic flexibility and risk of proximal junctional kyphosis

2021 ◽  
pp. 1-7
Author(s):  
Francis Lovecchio ◽  
Renaud Lafage ◽  
Jonathan Charles Elysee ◽  
Alex Huang ◽  
Bryan Ang ◽  
...  
Keyword(s):  
Thoracic Spine ◽  
Lumbar Lordosis ◽  
Pelvic Tilt ◽  
Pelvic Incidence ◽  
Vertical Axis ◽  
Control Analysis ◽  
Proximal Junctional Kyphosis ◽  
Sagittal Vertical Axis ◽  
Significant Difference ◽  
Junctional Kyphosis

OBJECTIVE Supine radiographs have successfully been used for preoperative planning of lumbar deformity corrections. However, they have not been used to assess thoracic flexibility, which has recently garnered attention as a potential contributor to proximal junctional kyphosis (PJK). The purpose of this study was to compare supine to standing radiographs to assess thoracic flexibility and to determine whether thoracic flexibility is associated with PJK. METHODS A retrospective study was conducted of a single-institution database of patients with adult spinal deformity (ASD). Sagittal alignment parameters were compared between standing and supine and between pre- and postoperative radiographs. Thoracic flexibility was determined as the change between preoperative standing thoracic kyphosis (TK) and preoperative supine TK, and these changes were measured over the overall thoracic spine and the fused portion of the thoracic spine (i.e., TK fused). A case-control analysis was performed to compare thoracic flexibility between patients with PJK and those without (no PJK). The cohort was also stratified into three groups based on thoracic flexibility: kyphotic change (increased TK), lordotic change (decreased TK), and no change. The PJK rate was compared between the cohorts. RESULTS A total of 101 patients (mean 63 years old, 82.2% female, mean BMI 27.4 kg/m2) were included. Preoperative Scoliosis Research Society–Schwab ASD classification showed moderate preoperative deformity (pelvic tilt 27.7% [score ++]; pelvic incidence–lumbar lordosis mismatch 44.6% [score ++]; sagittal vertical axis 42.6% [score ++]). Postoperatively, the average offset from age-adjusted alignment goals demonstrated slight overcorrection in the study sample (−8.5° ± 15.6° pelvic incidence–lumbar lordosis mismatch, −29.2 ± 53.1 mm sagittal vertical axis, −5.4 ± 10.8 pelvic tilt, and −7.6 ± 11.7 T1 pelvic angle). TK decreased between standing and supine radiographs and increased postoperatively (TK fused: −25.3° vs −19.6° vs −29.9°; all p < 0.001). The overall rate of radiographic PJK was 23.8%. Comparisons between PJK and no PJK demonstrated that offsets from age-adjusted alignment goals were similar (p > 0.05 for all). There was a significant difference in the PJK rate when stratified by thoracic flexibility cohorts (kyphotic: 0.0% vs no change: 18.4% vs lordotic: 35.0%; p = 0.049). Logistic regression revealed thoracic flexibility (p = 0.045) as the only independent correlate of PJK. CONCLUSIONS Half of patients with ASD experienced significant changes in TK during supine positioning, a quality that may influence surgical strategy. Increased thoracic flexibility is associated with PJK, possibly secondary to fusing the patient’s spine in a flattened position intraoperatively.

scholarly journals Normal Age-Adjusted Sagittal Spinal Alignment Is Achieved with Surgical Correction in Adolescent Idiopathic Scoliosis

2017 ◽  
Vol 11 (5) ◽  
pp. 770-779 ◽  
Author(s):  
Subaraman Ramchandran ◽  
Norah Foster ◽  
Akhila Sure ◽  
Thomas J. Errico ◽  
Aaron J. Buckland
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Lumbar Lordosis ◽  
Thoracic Kyphosis ◽  
Pelvic Incidence ◽  
Sagittal Alignment ◽  
Vertical Axis ◽  
Surgical Correction ◽  
Sagittal Vertical Axis

<sec><title>Study Design</title><p>Retrospective analysis.</p></sec><sec><title>Purpose</title><p>Our hypothesis is that the surgical correction of adolescent idiopathic scoliosis (AIS) maintains normal sagittal alignment as compared to age-matched normative adolescent population.</p></sec><sec><title>Overview of Literature</title><p>Sagittal spino-pelvic alignment in AIS has been reported, however, whether corrective spinal fusion surgery re-establishes normal alignment remains unverified.</p></sec><sec><title>Methods</title><p>Sagittal profiles and spino-pelvic parameters of thirty-eight postsurgical correction AIS patients ≤21 years old without prior fusion from a single institution database were compared to previously published normative age-matched data. Coronal and sagittal measurements including structural coronal Cobb angle, pelvic incidence, pelvic tilt, thoracic kyphosis, lumbar lordosis, sagittal vertical axis, C2–C7 cervical lordosis, C2–C7 sagittal vertical axis, and T1 pelvic angles were measured on standing full-body stereoradiographs using validated software to compare preoperative and 6 months postoperative changes with previously published adolescent norms. A sub-group analysis of patients with type 1 Lenke curves was performed comparing preoperative to postoperative alignment and also comparing this with previously published normative values.</p></sec><sec><title>Results</title><p>The mean coronal curve of the 38 AIS patients (mean age, 16±2.2 years; 76.3% female) was corrected from 53.6° to 9.6° (80.9%, <italic>p</italic>&lt;0.01). None of the thoracic and spino-pelvic sagittal parameters changed significantly after surgery in previously hypo- and normo-kyphotic patients. In hyper-kyphotic patients, thoracic kyphosis decreased (<italic>p</italic>=0.003) with a reciprocal decrease in lumbar lordosis (<italic>p</italic>=0.01), thus lowering pelvic incidence-lumbar lordosis mismatch mismatch (<italic>p</italic>=0.009). Structural thoracic scoliosis patients had slightly more thoracic kyphosis than age-matched patients at baseline and surgical correction of the coronal plane of their scoliosis preserved normal sagittal alignment postoperatively. A sub-analysis of Lenke curve type 1 patients (n=24) demonstrated no statistically significant changes in the sagittal alignment postoperatively despite adequate coronal correction.</p></sec><sec><title>Conclusions</title><p>Surgical correction of the coronal plane in AIS patients preserves sagittal and spino-pelvic alignment as compared to age-matched asymptomatic adolescents.</p></sec>

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