Degenerative Scoliosis Patients Research Articles

99. Impact of decompression location for lumbar canal stenosis in degenerative scoliosis patients with Cobb angle over 20°

99. Impact of decompression location for lumbar canal stenosis in degenerative scoliosis patients with Cobb angle over 20°

Preoperative Planning of Lumbar Lordosis for Adult Degenerative Scoliosis Surgery in the Chinese Population

Pelvic incidence minus lumbar lordosis mismatch (PI-LL) is directly related to poor quality of life in adult degenerative scoliosis (ADS) patients. The purpose of the study was to determine the most appropriate postoperative PI-LL value for patients with ADS. The medical records of patients with ADS in our department were retrospectively collected. The data included age, sex, body mass index, age-adjusted Charlson comorbidity index, osteopenia, length of hospital stay, operative duration, estimated blood loss, American Society of Anesthesiologists score, number of fusion levels, lumbar lordosis, sagittal vertical axis, pelvic incidence, PI-LL, Scoliosis Research Society-22 score, Oswestry Disability Index score, and mechanical complications. A total of 316 patients were enrolled. PI-LL, lumbar lordosis, sagittal vertical axis, Scoliosis Research Society-22 score, Oswestry Disability Index score at the time of last follow-up were 20.7 ± 8.5°, 23.4 ± 14.1°, 4.0 ± 2.1cm, 3.7 ± 0.9, and 18.1 ± 5.5, respectively. In terms of mechanical complications, 88 patients (27.8%), 34 patients (10.8%), and 19 patients (6.0%) had proximal junctional kyphosis, distal junctional kyphosis, and implant-related complications, respectively. In the fully adjusted model, compared with 0 grade PI-LL group and++ grade PI-LL group,+ grade PI-LL group had the best clinical outcomes and the fewest mechanical complications. The stability of these conclusions was verified in sensitivity analyses. Optimal PI-LL value should be 10°-20° after corrective surgery in patients with ADS, which is associated with excellent clinical outcomes and lower complication rates. Previous criteria may be at risk of overcorrection, which may lead to proximal junctional kyphosis.

Defining Age-Adjusted PI-LL Targets for Surgical Realignment in Adult Degenerative Scoliosis: A Retrospective Cohort Study.

Objectives: The purpose of this study was to investigate postoperative pelvic incidence minus lumbar lordosis mismatch (PI-LL) and health-related quality of life (HRQOL) outcomes to determine age-adjusted PI-LL targets. Method: The dataset encompassed a range of variables, including age, sex, body mass index, Charlson comorbidity index, presence of osteopenia, hospital stay, operative duration, blood loss, American Society of Anesthesiologists score, number of fusion levels, lumbar lordosis, sagittal vertical axis, pelvic incidence, and PI-LL. The non-linear relationship between PI-LL and clinical outcomes was examined using a curve analysis, with adjustments made for potential confounding variables. Upon identification of a non-linear relationship, a two-piecewise regression model was employed to determine the threshold effect. Results: A total of 280 patients were enrolled. In the fully adjusted model, the optimal PI-LL target for patients aged 45-54 years old was PI-LL < 10°, the optimal target for patients aged 55-74 was 10-20°, and the optimal target for patients older than 75 years was more suitable for PI-LL > 20°. In the curve-fitting graph, it could be seen that the relationship between PI-LL and HRQOL outcomes was not linear in each age group. The peaks of the curves within each group occurred at different locations. Higher and lower thresholds for optimal surgical goals were determined using the two-piecewise regression model from the SRS-22 score and the ODI score. Conclusions: This study showed that the optimal PI-LL after corrective surgery in adult degenerative scoliosis patients should be adjusted according to age.

Influence of paraspinal muscle degeneration and postoperative Roussouly classification restoration on mechanical complications in female patients with degenerative scoliosis after surgery

Objective: To investigate the impact of lumbar paraspinal muscle degeneration and postoperative failure to restore ideal Roussouly classification on the occurrence of mechanical complications (MC) following long-segment spinal correction surgery in female patients with degenerative scoliosis (DS). Methods: The clinical data of 72 female DS patients who underwent long-segment spinal correction surgery in Gulou Hospital from June 2017 to November 2021 were retrospectively analyzed. According to whether restoring the ideal Roussouly classification after surgery, the patients were divided into R group(recovery group) (n=51) and N group(non-recovery group) (n=21). According to whether mechanical complications occurred after operation within two years, the patients were divided into MC (mechanical complications)group (n=24) and NMC(non-mechanical complications) group (n=48). The RM group (n=14) experienced mechanical complications in the R group, while the RN group (n=37) did not. The NM group (n=10) experienced mechanical complications in the N group, while the NN group (n=11) did not.Radiographic assessment included Sagittal parameters of spine and pelvis, standardized cross-sectional area (SCSA) and fat infiltration rate (FI%) of paraspinal muscle at each lumbar disc level. Results: The age of DS patients in this study was (61.4±6.2) years.The incidence of MC was 33.33%(n=24)in all patients. The incidence of MC was 27.45%(n=14)in group R and 47.62%(n=10) in group N. The correction amount of pelvic tilt angle (PT) (-11.62°±10.06° vs -7.04°±8.45°, P=0.046) and T1 pelvic angle(TPA)(-12.88°±11.23° vs -7.31°±9.55°, P=0.031)during surgery were significantly higher in MC group compared to the NMC group. In group R, the FI% of paraspinal muscles in each lumbar segment of patients with postoperative MC was higher than that in patients without MC (P<0.05). In the R and N groups, there was no significant difference inthe SCSA of the lumbar paravertebral muscles between patients with postoperative MC and those without MC at each level (all P>0.05). Multivariate logistic regression analysis showed that the average FI% of lumbar PSM was correlated with the occurrence of MC after spinal fusion in DS patients.The average FI% of lumbar PSM≥22.63% was a risk factors for MC after spinal fusion (P=0.010,OR=1.088, 95%CI:1.020-1.160). Conclusions: Female DS patients with higher degree of preoperative paraspinal muscle degeneration have a higher incidence of postoperative mechanical complications. For these patients,.there is still a higher risk of mechanical complications after surgery even if the ideal Roussouly classification is restored after surgery.

Development and validation of AI-based automatic measurement of coronal Cobb angles in degenerative scoliosis using sagittal lumbar MRI

ObjectivesSeverity of degenerative scoliosis (DS) is assessed by measuring the Cobb angle on anteroposterior radiographs. However, MRI images are often available to study the degenerative spine. This retrospective study aims to develop and evaluate the reliability of a novel automatic method that measures coronal Cobb angles on lumbar MRI in DS patients.Materials and methodsVertebrae and intervertebral discs were automatically segmented using a 3D AI algorithm, trained on 447 lumbar MRI series. The segmentations were used to calculate all possible angles between the vertebral endplates, with the largest being the Cobb angle. The results were validated with 50 high-resolution sagittal lumbar MRI scans of DS patients, in which three experienced readers measured the Cobb angle. Reliability was determined using the intraclass correlation coefficient (ICC).ResultsThe ICCs between the readers ranged from 0.90 (95% CI 0.83–0.94) to 0.93 (95% CI 0.88–0.96). The ICC between the maximum angle found by the algorithm and the average manually measured Cobb angles was 0.83 (95% CI 0.71–0.90). In 9 out of the 50 cases (18%), all readers agreed on both vertebral levels for Cobb angle measurement. When using the algorithm to extract the angles at the vertebral levels chosen by the readers, the ICCs ranged from 0.92 (95% CI 0.87–0.96) to 0.97 (95% CI 0.94–0.98).ConclusionThe Cobb angle can be accurately measured on MRI using the newly developed algorithm in patients with DS. The readers failed to consistently choose the same vertebral level for Cobb angle measurement, whereas the automatic approach ensures the maximum angle is consistently measured.Clinical relevance statementOur AI-based algorithm offers reliable Cobb angle measurement on routine MRI for degenerative scoliosis patients, potentially reducing the reliance on conventional radiographs, ensuring consistent assessments, and therefore improving patient care.Key Points• While often available, MRI images are rarely utilized to determine the severity of degenerative scoliosis.• The presented MRI Cobb angle algorithm is more reliable than humans in patients with degenerative scoliosis.• Radiographic imaging for Cobb angle measurements is mitigated when lumbar MRI images are available.Graphical

Development of ethnicity-adjusted global alignment and proportion score to predict the risk of mechanical complications following corrective surgery for adult spinal deformity

BACKGROUND CONTEXTSurgery for degenerative scoliosis (DS) is a complex procedure with high complication and revision rates. Based on the concept that pelvic incidence (PI) is a constant parameter, the global alignment and proportional (GAP) score was developed from sagittal alignment data collected in the Caucasian populations to predict mechanical complications. However, the PI varies among different ethnic groups, and the GAP score may not apply to Chinese populations. Thus, this study aims to assess the predictability of the GAP score for mechanical complications in the Chinese populations and develop an ethnicity-adjusted GAP score. PURPOSETo test the predictability of the original GAP score in the Chinese population and develop a Chinese ethnicity-tailored GAP scoring system. STUDY DESIGN/SETTINGSRetrospective cohort study. PATIENT SAMPLEA total of 560 asymptomatic healthy volunteers were enrolled to develop Chinese ethnicity-tailored GAP (C-GAP) score and a total of 114 DS patients were enrolled to test the predictability of original GAP score and C-GAP score. OUTCOME MEASURESDemographic information, sagittal spinopelvic parameters of healthy volunteers and DS patients were collected. Mechanical complications were recorded at a minimum of 2-year follow-up after corrective surgery for DS patients. METHODSA total of 560 asymptomatic healthy volunteers with a mean age of 61.9±14.1 years were enrolled to develop ethnicity-adjusted GAP score. Besides, 114 surgically trated DS patients (M/F=10/104) with a mean age of 60.7±7.1 years were retrospectively reviewed. Demographic data and radiological parameters of both groups, including PI, lumbar lordosis (LL), sacral slope (SS), the sagittal vertical axis (SVA), and global tilt (GT) were collected. Ideal LL, SS, and GT were obtained by calculating their correlation with PI of healthy volunteers using linear regression analysis. Relative pelvic version (RPV), relative lumbar lordosis (RLL), lordosis distribution index (LDI), and relative spinopelvic alignment (RSA) were obtained using the ideal parameters, and the Chinese population adjusted GAP score (C-GAP) was developed based on these values. The predictability of original and C-GAP for mechanical failure was evaluated using clinical and radiological data of DS patients by evaluating the area under the curve (AUC) using receiver operating characteristic curve. This study was supported the National Natural Science Foundation of China (NSFC) (No. 82272545), ($ 8,000–10,000) and the Jiangsu Provincial Key Medical Center, and the China Postdoctoral Science Foundation (2021M701677), Level B ($ 5,000–7,000). RESULTSIdeal SS=0.53×PI+9 (p=.002), ideal LL=0.48×PI+22 (p=.023) and ideal GT=0.46 × PI-9 (p=.011). were obtained by correlation analysis using sagittal parameters from those healthy volunteers, and RPV, RLL, RSA, and LDI were calculated accordingly. Then, the ethnicity-adjusted C-GAP score was developed by summing up the numeric value of calculated RPV, RLL, RSA, and LDI. The AUC was classified as ‘‘no or low discriminatory power’’ for the original GAP score in predicting mechanical complications (AUC=0.592, p=.078). Similarly, the original GAP score did not correlate with mechanical complications in DS patients. According to the C-GAP score, the sagittal parameters were proportional in 25 (21.9%) cases, moderately disproportional in 68 (59.6%), and severely disproportional in 21% (18.5%) cases. The incidence of mechanical complications was statistically different among proportioned and moderately disproportional and severely disproportional portions of the C-GAP score (p=.03). The predictability of the C-GAP score is high with an AUC=0.773 (p<.001). In addition, there is a linear correlation between mechanical complication rate and C-GAP score (χ=0.102, p=.02). CONCLUSIONThe Ethnicity-adjusted C-GAP score system developed in the current study provided a more accurate and reliable for predicting the risk of mechanical complications after corrective surgery for adult spinal deformity.

Outcomes of Ponte osteotomy combined with posterior lumbar interbody fusion for reconstruction of coronal and sagittal balance in degenerative scoliosis

PurposeThe purpose of the study was to evaluate the clinical efficacy and safety of using Ponte osteotomy combined with posterior lumbar interbody fusion in the treatment of patients with degenerative scoliosis.MethodThe medical records and imaging data of degenerative scoliosis patients in our department from 2013 to 2022 were retrospectively collected. A total of 47 patients were included, including 16 male patients and 31 female patients. The mean follow-up was 47.8 months. Whole spine X-rays in the standing position were performed on all patients preoperatively, postoperatively, and at the latest follow-up. The length of hospital stay, complications, operative duration, estimated blood loss, instrumented segment, fused segment, clinical scores, and various radiological indicators were recorded.ResultsThe coronal vertical axis improved from 3.1 ± 1.9 cm preoperatively to 1.2 ± 1.0 cm postoperatively with an average reduction of 1.9 ± 1.7 cm. The preoperative coronal Cobb angle was 18.1 ± 10.6°, the immediate postoperative Cobb angle was 6.6 ± 3.9°, and the Cobb angle at the last follow-up was 5.8 ± 3.7°. The sagittal vertical axis decreased from 5.6 ± 3.7 cm preoperatively to 2.7 ± 1.9 cm immediately after the operation and was well maintained at the last follow-up (3.1 ± 2.5 cm). Lumbar lordosis increased from 22.2 ± 10.2° preoperatively to 40.4 ± 8.3° postoperatively and 36.0 ± 8.8° at the last follow-up. The ODI score, VAS low back pain score, and VAS leg pain score were also improved to varying degrees.ConclusionPonte osteotomy combined with posterior lumbar interbody fusion can significantly improve coronal and sagittal plane deformities and postoperative functional scores in patients with adult degenerative scoliosis.

Clinical Application of the Roussouly Classification in the Sagittal Balance Reconstruction of 101 Adolescent Idiopathic Scoliosis Patients.

Although Roussouly classification has been widely used in spinal surgery, it was mainly applied to degenerative scoliosis patients and correlational studies concerning adolescent idiopathic scoliosis (AIS) are still insufficient. This retrospective study explored the clinical application of Roussouly classification in surgeries and prognosis prediction for AIS. This clinical research selected 101 AIS patients who received surgeries between August 2005 and November 2019. Whole spine standing radiographs were obtained for each patient preoperatively, postoperatively, and at the last follow-up (>24months). All patients were classified into "theoretical types" and "current types." Patients were further divided into mismatch or match groups based on the consistency of their current type and theoretical type. The main parameters include: proximal junctional angle (PJA), pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), fixed thoracic kyphosis (TK), global TK, fixed lumbar lordosis (LL), global LL, thoracic tilt, proximal thoracic alignment (PTA), lumbar tilt, spino-sacral angle (SSA), and spinal tilt (ST). A total of 47.5% of AIS patients were subject to a preoperative mismatch of Roussouly classification. There was a significant difference in PI-LL between the preoperative mismatch and match groups (p=0.008). There was a significant difference in the rate of PI-LL deformity between the match and mismatch groups with a preoperative mismatch (p=0.037). A significant difference in thoracic tilt was observed between the postoperative mismatch and match groups (p=0.019). The preoperative mismatch group has a higher risk of postoperative PI-LL malformation than match group (OR=2.303, 95% CI: 1.026, 5.165). When mismatch occurred postoperatively, there were significant differences between groups in the rate of pelvic deformity (p=0.002) and PI-LL deformity (p=0.025) at the last follow-up. Compared with the postoperative match group, mismatch group had an increased risk of pelvic deformity (OR=5.029, 95% CI: 1.618, 15.629) and PJK deformity (OR=3.017, 95% CI: 1.709, 11.375) at the last follow-up. Short Form-36 and Scoliosis Research Society 22 score of the match group was significantly higher than that of the mismatch group at the last follow-up. The Roussouly classification mismatch before or after operation leads to increased risks of PI-LL deformity and pelvis deformity postoperatively or at the follow-up, which seriously worsens the clinical symptoms and prognosis of patients. Therefore, recovering to the theoretical type in Roussouly classification may effectively improve patients' prognosis.

Focusing on the amount of immediate changes in spinopelvic radiographic parameters to predict the amount of mid-term improvement of quality of life in adult degenerative scoliosis patients with surgery

IntroductionSurgery is still an effective treatment option for adult degenerative scoliosis (ADS), but how to predict patients’ significant amount of the improvement in quality of life remains unclear. The previous studies included an inhomogeneous population. This study aimed to report the results about concentrating on the amount of immediate changes in spinopelvic radiographic parameters to predict the amount of mid-term improvement in quality of life in ADS patients.Materials and methodsPre-operative and immediately post-operative radiographic parameters included Cobb angle, coronal vertical axis (CVA), sagittal vertical axis (SVA), lumbar lordosis (LL), thoracic kyphosis (TK), pelvic tilt (PT), sacral slope (SS), pelvic incidence (PI) and LL/PI matching (PI–LL). Quality of life scores were evaluated pre-operatively and at the final follow-up using Oswestry Disability Index (ODI) and visual analogue scale (VAS). The amount of immediate changes in spinopelvic radiographic parameters (Δ) and the amount of mid-term improvement in quality of life (Δ) were defined, respectively.ResultsPatients showed significant change in radiographic parameters, ODI and VAS pre- and post-surgery, except CVA and PI. Univariate analysis showed a significant correlation between ΔTK, ΔLL, ΔCVA and the amount of mid-term improvement in quality of life, but multivariate analysis did not get a significant result. Univariate and multivariate analyses showed that ΔSVA was still a significant predictor of ΔVAS and ΔODI. The changes in the other radiographic parameters were not significant. The equations were developed by linear regression: ΔODI = 0.162 × ΔSVA − 21.592, ΔVAS = 0.034 × ΔSVA − 2.828. In the ROC curve for ΔSVA in the detection of a strong ΔODI or ΔVAS, the cut-off value of ΔSVA was − 19.855 mm and − 15.405 mm, respectively.ConclusionsThis study shows that ΔSVA can predict the amount of mid-term improvement in quality of life in ADS patients. The changes in the other radiographic parameters were not significant. Two equations were yielded to estimate ΔODI and ΔVAS. ΔSVA has respective cut-off value to predict ΔODI and ΔVAS.

Sequential correction technique in degenerative scoliosis with type C coronal imbalance: a comparison with traditional 2-rod technique.

The aim of this study was to compare the radiographic and clinical outcomes in patients with degenerative scoliosis (DS) with type C coronal imbalance who underwent either a sequential correction technique or a traditional 2-rod technique with a minimum of 2 years of follow-up. DS patients with type C coronal imbalance undergoing posterior correction surgery from February 2014 to January 2018 were divided into groups by technique: the sequential correction technique (SC group) and the traditional 2-rod technique (TT group). Radiographic parameters, including Cobb angle, coronal balance distance (CBD), global kyphosis (GK), thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT), and sacral slope, were assessed pre- and postoperatively. The SF-36 questionnaire was used to assess quality of life. A total of 34 patients were included. Significant postoperative improvement in the Cobb angle of the main curve, CBD, GK, TK, LL, SVA, and PT was found in both groups (p < 0.05). Postoperatively, the coronal balance was type A in 13 patients (92.9%) in the SC group and in 16 patients (80.0%) in the TT group (p = 0.298). In the TT group, 1 patient had deteriorative coronal imbalance immediately postoperatively, and coronal imbalance deteriorated from type A to type C in 2 patients during follow-up. The scores of Physical Functioning, Role-Physical, Bodily Pain, Vitality, Social Functioning, Role-Emotional, and Mental Health were statistically improved postoperatively (p < 0.05) in both groups. Type C coronal imbalance at the last follow-up was associated with a relatively worse quality of life. There were no implant failures during follow-up in the SC group, whereas rod fracture was observed in 3 patients in the TT group. Compared with the traditional 2-rod technique, the sequential correction technique can simplify rod installation procedure, enhance internal instrumentation, and reduce risk of implant failures. The sequential correction technique could be routinely recommended for DS patients with type C coronal imbalance.

67. The value of overall assessment in adult degenerative scoliosis patients: short- and long-term effect of surgical intervention on static and dynamic balance, gait and pain level

<h3>BACKGROUND CONTEXT</h3> In the diagnosis and treatment of adult spinal deformities, static radiographic measurements in the sagittal and coronal anatomical planes and patient-reported outcome measures (PROMs) serve as the gold standard for assessment of spinal alignment and deformity. However, there is a lack of published literature on their relation to objective functional outcome measures (FOMs) among patients afflicted with adult spinal deformity. Adult spinal deformity (ASD) is due to degeneration, functional decline is partly due to loss of postural stability and neuromuscular capacity and coordination. Objective functional measures (eg, static standing and walking alignment) cover more information than just radiographic alignment in the ASD population. Gait and dynamic balance analysis can reveal functional compensatory alignment changes where static imaging is limited. Previous studies have shown improvement in postoperative gait, approximating non-ASD control cohorts but still symptomatic. Many studies have shown surgical reconstruction in ASD patients has improved patient outcomes, but not overall assessment of objective function along with psychological factors. Therefore, a more comprehensive standard outcome measurement is needed. <h3>PURPOSE</h3> To determine the one-year effects of spinal alignment on function in ASD patients following surgical treatment using radiographic parameters, 3D gait and balance analysis, PROMs, and psychological tests and compared to healthy control. <h3>STUDY DESIGN/SETTING</h3> Nonrandomized, prospective study. <h3>PATIENT SAMPLE</h3> Forty-three symptomatic ASD patients, 24 age-matched control. <h3>OUTCOME MEASURES</h3> Gait spatiotemporal parameters, dynamic balance as measurement by balance effort and Cone of Economy (CoE) dimensions, radiograph alignment measurements, PROMs, and psychological factors. <h3>METHODS</h3> Patients performed dynamic balance and gait evaluations prior to surgery (Pre), 3 months (Post3), and 12 months (Post12) postoperatively. Patients also completed full-length, head-to-toe, micro-dose X-rays along with PROMs, and psychological questionnaires. Balance effort and CoE dimensions were measured by total sway and range of sway, respectively. Repeated measurement analysis of variance (ANOVA) and one-way ANOVA were used to determine differences in radiographic, dynamic balance, gait, and PROMs parameters at Post3 and Post12 and to the match control group. <h3>RESULTS</h3> Significant improvements in radiographic alignment were found in Cobb angle (<0.001), sagittal (<0.009) and coronal (<0.003) vertical axes and pelvic incidence-lumbar lordosis mismatch (<0.001) at Post3 and Post12. There were significant improvements in all PROMs after surgery (VAS mid-back, low back, and leg, ODI and SRS). Surgical intervention resulted in a significant decrease in balance effort (head: p<0.017 and center of mass: p<0.042) and reduced in the CoE dimensions (sagittal: p<0.004; and coronal: p=0.029). Gait was also enhanced after surgery as seen with a faster walking speed (p<0.024) and longer stride length (p<0.024). Psychological factors showed significant improvements in Tampa Scale for Kinesiophobia and Fear Avoidance Belief Questionnaire scores (p<0.050). <h3>CONCLUSIONS</h3> This is the first study to provide insight into a comprehensive global assessment of ASD surgery patients' function which includes complete objective functional and psychological outcomes in addition to standard PROMs and radiographic alignment. Balance effort and CoE limits improved at all time points post-operatively and ultimately matched the controls at 12 months. Similar to the significant improvement in static and dynamic balance in these patient groups, gait parameters also improved Post3 and Post12 to closely resemble the control group and continued to improve over time. Our findings present a more comprehensive set of outcome metrics, which, once combined, provide a more detailed and sensitive assessment of overall treatment outcomes. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Second sacral sacralalar\u2010iliac (S2AI) screw placement in adult degenerative scoliosis (ADS) patients: an imaging study

BackgroundThe imaging characteristics of sacral sacralalar-iliac (S2AI) screw trajectory in adult degenerative scoliosis (ADS) patients will be determined.MethodsS2AI screw trajectories were mapped on three-dimensional computed tomography (3DCT) reconstructions of 40 ADS patients. The starting point, placement plane, screw template, and a circle centered at the lowest point of the ilium inner cortex were set on these images. A tangent line from the starting point to the outer diameter of the circle was selected as the axis of the screw trajectory. The related parameters in different populations were analyzed and compared.ResultsThe trajectory length of S2AI screws in ADS patients was 12.00 ± 0.99 cm, the lateral angle was 41.24 ± 3.92°, the caudal angle was 27.73 ± 6.45°, the distance from the axis of the screw trajectory to the iliosciatic notch was 1.05 ± 0.81 cm, the distance from the axis of the screw trajectory to the upper edge of the acetabulum was 1.85 ± 0.33 cm, and the iliac width was 2.12 ± 1.65 cm. Compared with females, the lateral angle of male ADS patients was decreased, but the trajectory length was increased (P < 0.05). Compared to patients without ADS in previous studies, the lateral angle of male patients was larger, the lateral angle of female patients was increased, and the caudal angle was decreased (P < 0.05).ConclusionsThere is an ideal trajectory of S2AI screws in ADS patients. A different direction should be noticed in the placement of S2AI screws, especially in female patients.

An analysis of decompression alone in stable degenerative scoliosis patients in affecting back pain and deformity

Degenerative Scoliosis is well known for producing both neurological and mechanical symptoms in addition to producing deformity and sometimes instability. Decompression alone has been treatment of choice in patients with mild deformity with neurogenic claudication or radiculopathy but without instability. However, fusion has been preferred to counter deformity, instability and mechanical forces. We intended to study these variables when treated with decompression alone. We evaluated 38 patients who fulfilled our criteria. Demographic variables like age, gender, duration of symptoms and type of predominant symptom were noted. Clinical evaluation of back pain, deformity angle in supine and standing position was also performed both before and after surgery. Assessment was also done for type of symptoms and levels of decompression. We found no significant changes in deformity or back pain when decompression alone was done in such patients. The patients did improve symptomatically and neurologically. We found that decompression alone can be done to improve non-mechanical parameters in a patient of degenerative stable lumbar scoliosis.

Effectiveness of Short-Segment Fixation versus Long-Segment Fixation for Degenerative Scoliosis with Cobb Angle 20°~40°: A Retrospective Observational Study.

BackgroundThere remains a great deal of controversy regarding the selection of long-segment fixation and short-segment fixation, especially for degenerative scoliosis (DS) patients with Cobb angle 20°~40°. The purpose of this study was to investigate the effects of different fixation levels in DS patients with Cobb angle 20°~40°.Material/MethodsWe enrolled 96 DS patients, divided into a long-segment fixation group (>3 segments) and a short-segment fixation group (≤3 segments). The visual analogue scale (VAS) and Oswestry disability index (ODI) were used to evaluate the clinical outcomes. The spinal-pelvic parameters and complications were also collected and analyzed.ResultsThe short-segment fixation group had the advantages of less blood loss, shorter operation time and shorter fluoroscopy time (P<0.05). The 2 groups achieved similar effects in leg pain (VAS) and ODI after operation (P>0.05); however, there was a better relief of low back pain in the long-segment fixation group (P<0.05). The changes of Cobb angle, sagittal vertical axis (SVA), lumbar lordosis (LL), pelvic tilt (PT) and sacral slope (SS) in the long-segment fixation group were more obvious than that in the short-segment fixation group at the final follow-up (P<0.05). The prevalence of complications in the long-segment fixation group was significantly higher than in the short-segment fixation group (P<0.01).ConclusionsShort-segment fixation has less surgical trauma and fewer complications, whereas long-segment fixation has more advantages in improving spine-pelvis parameters and relieving low back pain.

What is actually happening inside the "cone of economy": compensatory mechanisms during a dynamic balance test.

A nonrandomized, prospective, concurrent control cohort study. To further develop cone of economy (CoE) measurements by identifying compensatory mechanisms at the extremes of the CoE and comparing balance control strategies in a group of adult degenerative scoliosis (ADS) patients with non-scoliotic controls. The CoE concept was first proposed by Dubousset and is frequently referred to when assessing balance in spinal deformity patients. Recently, a method that quantifies the CoE of individual patients through 3D video kinematic and electromyography data was developed. However, this method lacks measurements that describe the motor control strategies utilized by spinal disorder patients to maintain balance. Twenty ADS patients and 15 non-scoliotic controls. All test subjects were fitted with a full body marker set. Each subject performed a series of functional balance tests (Romberg's with eyes opened) while being recorded in a human motion capture system. Three-dimensional CoE dimensions, range of sway (RoS), overall sway and lower extremity and trunk range of motion (RoM) were measured and analyzed. Patients with ADS demonstrated greater overall sway and RoS in the sagittal and coronal planes compared to controls. Moreover, ADS patients presented with more hip flexion and trunk flexion at maximal points of sway and more ankle, knee, hip and trunk RoM when swaying in comparison with controls. ADS patients have larger CoE dimensions and increased sway when compared to non-scoliotic controls. ADS patients rely on a hip balance control "strategy" and lower extremity RoM to maintain balance, which differed from control subjects. Unlike prior attempts to define compensatory mechanisms in ADS patients, the described technique utilizes dynamic, three-dimensional measurements to define what is occurring within the CoE. By expanding on prior CoE measurements, we were able to define a unique dynamic balance control strategy for each patient.

Development and Application of Oblique Lumbar Interbody Fusion.

The present study reviewed the relevant recent literature regarding the development and application of oblique lumbar interbody fusion (OLIF), with a particular focus on its application and associated complications. The study evaluated the rationality of this technique and demonstrated the direction of future research by collecting data on previous operative outcomes and complications. A literature search was performed in Pubmed and Web of Science, including the following keywords and abbreviations: anterior lumbar interbody fusion (ALIF), lateral lumbar interbody fusion (LLIF), direct lateral interbody fusion (DLIF), extreme lateral interbody fusion (XLIF), oblique lateral interbody fusion (OLIF), adjacent segment disease (ASD), and adult degenerative scoliosis (ADS). A search of literature published from January 2005 to January 2019 was conducted and all studies evaluating development and application of OLIF were included in the review. According to the literature, the indications for OLIF are various. OLIF has excellent orthopaedic effects in degenerative scoliosis patients and the incidence of bony fusion is higher than for other approaches. It also provides a better choice for revision surgery. It has various advantages in many aspects, but the complications cannot be ignored. As a new minimally invasive technique, the advantages of OLIF are obvious, but further evaluation is needed to compare its operation‐related data with that of traditional open surgery. In addition, more prospective studies are required to compare minimally invasive and open spinal surgery to confirm its specific efficacy, risk, advantages, learning curve, and ultimate clinical efficacy.

Kinematic comparison of the use of walking sticks versus a rolling walker during gait in adult degenerative scoliosis patients.

A repeated-measurement, single-center, prospective study. To compare the spatiotemporal and kinematic data using gait analysis in adult degenerative scoliosis (ADS) patients using walking sticks (WS) versus rolling walkers (RW). ADS patients undergo compensatory changes that can result in an altered gait pattern. RW are frequently prescribed, but result in a forward flexed kyphotic posture during ambulation. Gait using WS allows for more upright alignment in ADS patients. Fifty-three ADS patients with symptomatic degenerative scoliosis performed over-ground walking at self-selected speed with WS and with a RW. Trunk and lower extremity angles along with spatiotemporal parameters were measured and compared. When using WS, patients exhibited less flexion at the head (WS: - 4.8° vs. RW: 11.0°, p = 0.001), and lumbar spine (WS: - 0.9° vs. RW: 4.2°, p = 0.001); while there was significantly more extension, of the cervical spine (WS: - 1.6° vs. RW: - 7.4°, p = 0.002) when using the RW. At the initial contact phase of gait, patients using WS showed decreased flexion at the ankle (WS 0.7° vs. RW: 3.8°, p = 0.018), knee (WS: 0.3° vs. RW: 4.8°, p = 0.001), hip (WS: 22.6° vs. RW: 27.3°, p = 0.001), and pelvis (WS: 10.2° vs. RW: 14.8°, p = 0.001). In contrast, the use of WS resulted in slower ambulation (WS: 0.6m/s vs. RW: 0.7m/s, p = 0.001). In ADS patients who have not undergone surgical correction, the use of WS resulted in a more upright posture, which may be more beneficial to the compensatory changes that lead to gait disturbance in ADS patients. Ambulation using WS resulted in slower gait versus a RW, due to the momentum induced by the forward flexed posture when using a RW. We recommend the use of WS for patients with ADS as it improves gait kinematics and may be a safer option.

Efficacy of sequential correction based on satellite rod techniquein degenerative scoliosis with B-type coronal imbalance

Objective: To evaluate the radiographic and clinical outcomes of sequential correction based on satellite rod technique in degenerative scoliosis (DS) with B-type coronal imbalance, and to investigate the efficacy of sequential correction in this cohort. Methods: Twenty-one DS patients with B-type coronal imbalance applying sequential correction from December 2015 to July 2017 in Nanjing Drum Tower Hospital were retrospectively reviewed. There were 4 males and 17 females in this group, the average age was (63±8) years. The coronal parameters including Cobb angle of main curve and distance between C(7) plumb line and center sacral vertical line (C(7)PL-CSVL), as well as sagittal parameters including global kyphosis (GK) and sagittal vertical axis (SVA) were assessed pre-operatively, post-operatively and at the last follow-up. The Scoliosis Research Society-22 (SRS-22) questionnaire was fulfilled before the operation and at each follow-up to evaluate the quality of life. Paired t test was performed for statistical analysis. Results: The patients were followed-up for (20±8) months. The post-operative Cobb angle of main curve was significantly improved from 52°±12° to 19°±7° (t=13.886, P<0.01), and it was 19°±8° at the last follow-up and no significant correction loss was attained (t=1.101, P=0.284). The values of C(7)PL-CSVL before the operation, after the operation and at the final follow-up were (46±11) mm, (12±7) mm and (12±7) mm, respectively; significant post-operative improvement achieved (t=19.718, P<0.01) while there was no correction loss at last follow-up (t=-1.393, P=0.179). After sequential correction, 20 patients (95.2%) improved to A-type coronal imbalance while 1 patient (4.8%) remained with B-type coronal imbalance. Significant post-operative improvements were found in terms of GK and SVA and no significant correction loss was found during follow-up. The scores of pain and self-image showed significant improvement at the last follow-up (t=8.706, 3.104, both P<0.01). In addition, there was no implant failure during follow-up. Conclusion: The sequential correction based on satellite rod technique in DS patients with B-type coronal imbalance corrects the deformity, relieves the clinical symptoms, improves the quality of life, and decreases the rates of post-operative coronal imbalance as well as implant-related complications.

Clinical study of E-PASS system for peri-operative morbidity of spinal surgery for degenerative scoliosis

Objective To evaluate the feasibility of the Estimation of Physiologic Ability and Surgical Stress (E-PASS) system to predict peri-operative risk in degenerative scoliosis patients scheduled for spinal surgery. Methods Clinical data of 227 cases with degenerative scoliosis (Male∶Female=57∶170, Mean age=66.2±7.7 years), who accepted the operation of instrumentation and fusion in our hospital from January 2013 to July 2017, were retrospectively reviewed according to the E-PASS system, including peri-operative complications. Both hospital stayand post-operative hospital staywere compared between the groups with and withoutthe complications using t test. All E-PASS scores, including Preoperative Risk Score (PRS), Surgical Stress Score (SSS) and Comprehensive Risk Score (CRS), were analyzed between the two groups using Mann-Whitney Utest.The relationship between complications and PRS, SSS and CRS were analyzed using Spearmancorrelation analysis. The predictiveaccuracy of PRS, SSS and CRS were analyzed using the area under the receiver operating characteristic (ROC) curve (AUC). Results There were a total of 47 patients (20.7%) suffering peri-operative complications, including 27 cases (11.9%) with complications at surgical sites and 23 cases (10.1%) with complications at non-surgical sites. Both hospital stay (t=-4.722, P<0.001)and post-operative hospital stay (t= -4.867, P<0.001) were increased because of the complications. All E-PASS scores, including PRS (P=0.005), SSS (P=0.003) and CRS (P<0.001) were significantly higher in patients with peri-operative complications and they were linearly correlated with the overall incidence of the complications(ρ=0.185-0.259). In particular, PRS was correlated with complications at non-surgical sites (ρ=0.162) and SSS with surgical site complications(ρ=0.162). The area under the receiver operating characteristic curve (AUC) for PRS and SSS was higher in patients with complications at non-surgical and surgical sites (AUC=0.655 and 0.650), respectively.The AUC for CRS exhibited good predictive power for both types of complications (AUC=0.662 and 0.631). Conclusion The peri-operative morbidity of spinal surgery for degenerative scoliosis was relatively higher. The E-PASS system could correctly predict the morbidity. Key words: Adult; Lumbar vertebrae; Intervertebral disc degeneration; Scoliosis; Spinal fusion; Intraoperative complications; Postoperative complications

Does lumbar lordosis minus thoracic kyphosis predict the clinical outcome of patients with adult degenerative scoliosis?

PurposeTo evaluate the predictive effect of lumbar lordosis minus thoracic kyphosis (LL-TK) in the surgical outcome of adult degenerative scoliosis (ADS) patients and explore the optimum target base on it.MethodsThe preoperative and postoperative data including radiographic image and functional evaluation (Visual Analog Scale, VAS; Oswestry Disability Index, ODI; Japanese Orthopaedic Association, JOA) of 130 patients with ADS who underwent corrective surgery was retrospectively reviewed. The relationship between sagittal parameters and surgical outcome was assessed by using the Pearson correlation analysis. Receiver operating characteristic (ROC) curve was used to define the optimum cutoff value of LL-TK. Patients were divided into two groups based on LL-TK to compare the preoperative and postoperative status.ResultsLL-TK assessed soon after surgery strongly correlated with health-related quality of life (HRQOL) and sagittal vertical axis (SVA) at last follow-up. The cutoff value of LL-TK was set at 10° to determine a good clinical outcome (ODI < 20) and sagittal balance (SVA < 50 mm). Patients with LL-TK > 10° presented significantly better postoperative VAS, ODI, JOA, and SVA than patients with LL-TK < 10°.ConclusionLL-TK could effectively predict postoperative HRQOL and sagittal balance for patients with ADS. Patients with LL-TK > 10° showed a better clinical outcome and sagittal balance, so LL-TK > 10° could be the optimum corrective target for these patients.