Fusion For Degenerative Lumbar Scoliosis Research Articles

The Influence of Radiographic Parameter on the S2 Alar-Iliac Screw Virtual Trajectory in Degenerative Lumbar Scoliosis Patients: A Computed Tomography Study.

S2 alar-iliac (S2AI) screw had been widely used in the pelvic fusion for degenerative lumbar scoliosis (DLS) patients. However, whether S2AI screw trajectory was influenced by sagittal profile in DLS patients had not been comprehensively investigated. The objective of this study was to evaluate the associations between the optimal S2 alar-iliac (S2AI) screw trajectory and sagittal spinopelvic parameters in DLS patients. Computed tomography (CT) scans of pelvis were performed in 47 DLS patients for three-dimensional reconstruction of S2AI screw trajectory from September 2019 to November 2021. Five S2AI screw trajectory parameters were measured in CT reconstruction images, including: 1) angle in the transverse plane (Tsv angle); 2) angle in the sagittal plane (Sag angle); 3) maximal screw length; 4) screw width; and 5) skin distance. The lumbar Cobb angle, lumbar apical vertebral translation (AVT); global kyphosis (GK); thoracic kyphosis (TK); lumbar lordosis (LL); sagittal vertical axis (SVA); sacral slope (SS); pelvic tilt (PT); and pelvic incidence (PI) were measured in standing X-ray films of the whole spine and pelvis. Both Tsv angle and Sag angle had significant positive associations with SS (p < 0.05) but negative associations with both PT (p < 0.05) and LL (p < 0.05) in all cases. Patients with SS less than 15° had both smaller Tsv angle and Sag angle than those with SS equal to or more than 15° (p < 0.05). The decreased LL would lead to the backward rotation of the pelvis, resulting in a more cephalic and less divergent trajectory of S2AI screw in DLS patients. For DLS patients with lumbar kyphosis, spine surgeons should avoid both excessive Tsv and Sag angles for S2AI screw insertion, especially when using free-hand technique.

Risk Factors for Distal Junctional Problems Following Long Instrumented Fusion for Degenerative Lumbar Scoliosis: Are they Related to the Paraspinal Muscles.

Although the incidence of distal junctional problems (DJPs) following long construct-based treatment for degenerative lumbar scoliosis (DLS) is lower, affected patients are more likely to require revision surgery when they occur. So the aim of this study is to identify risk factors associated with DJPs to avoid its occurrence by at least 1-year follow-up. A total of 182 DLS patients undergoing long instrumented fusion surgery (≥4 levels) between February 2011 and March 2022 were retrospectively analyzed. Patients were placed into the DJP group if a DJP occurred at the final follow-up; patients without mechanical complications were matched 1:2 according to age, sex and BMI as the control group. Patient characteristics, surgical variables, radiographic parameters, lumbar muscularity and fatty degeneration were analyzed statistically. The statistical differences in the results between the two groups (p values <0.05) and other variables selected by experts were entered into a multivariate logistic regression model, and the forwards likelihood ratio method was used to analyze the independent risk factors for DJPs. Twenty-four (13.2%) patients suffered a DJP in the postoperative period and the reoperation rate was 8.8%. On univariate analysis, the lowest instrumented vertebra (LIV) CT value (p = 0.042); instrumented levels (p = 0.030); preoperative coronal vertical axis (CVA) (p = 0.046), thoracolumbar kyphosis (TLK) (p = 0.006), L4-S1 lordosis (p = 0.013), sacral slop (SS) (p = 0.030), pelvic tilt (PT) classification (p = 0.004), and sagittal vertical axis (SVA) (p = 0.021); TLK correction (p = 0.049); post-operative CVA (p = 0.029); Overall, There was no significant difference in the paraspinal muscle parameters between the two groups. On multivariate analysis, instrumented levels (OR = 1.595; p = 0.035), preoperative SVA (OR = 1.016; p = 0.022) and preoperative PT (OR = 0.873; p = 0.001) were identified as significant independent risk factors for DJP. Longer instrumented levels, a greater preoperative SVA and a smaller PT were found to be strongly associated with the presence of DJPs in patients treated for DLS. The degeneration of the paraspinal muscles may not be related to the occurrence of DJPs. For DLS patients, the occurrence of DJP can be reduced by selecting reasonable fusion segments and evaluating the patient's sagittal balance and spino-pelvic parameters before operation.

P114. The role of lumbosacral paraspinal muscle degeneration and low vertebral bone mineral density on distal instrumentation-related problems following long spinal fusion for degenerative lumbar scoliosis: a retrospective cohort study

P114. The role of lumbosacral paraspinal muscle degeneration and low vertebral bone mineral density on distal instrumentation-related problems following long spinal fusion for degenerative lumbar scoliosis: a retrospective cohort study

The role of lumbosacral paraspinal muscle degeneration and low vertebral bone mineral density on distal instrumentation-related problems following long-instrumented spinal fusion for degenerative lumbar scoliosis: a retrospective cohort study.

This study aimed to confirm the role of paraspinal muscle degeneration and low vertebral bone mineral density (vBMD) of the lumbosacral region in the development of distal instrumentation-related problems (DIPs) in degenerative lumbar scoliosis (DLS) patients undergoing long-instrumented spinal fusion. From 2013 to 2019, 125 DLS patients with 24-month follow-up after long-instrumented spinal fusion in Beijing Chao-Yang Hospital were retrospectively recruited and divided into DIP and non-DIP groups. Demographic characteristics, surgical data, and radiographic parameters were statistically compared between the groups. Degeneration of the paraspinal muscle was evaluated using the relative gross cross-sectional area (rGCSA), relative functional cross-sectional area (rFCSA), ratio of the rFCSA to rGCSA, gross muscle-fat index, and functional muscle-fat index of the multifidus (MF), erector spinae (ES), paraspinal extensor muscle (PSE), and psoas major determined by preoperative magnetic resonance imaging (MRI). The vBMD of the lumbosacral region and lower instrumented vertebra (LIV) was assessed using Hounsfield unit (HU) values determined by computed tomography (CT) scans. The DeLong test was performed to select MRI and CT scan variables. Multivariable logistic regression analysis was applied to determine the independent predictive factors of DIPs. The incidence of DIPs was 16.0% (20/105). There were no significant differences in demographic characteristics or surgical data between the groups. The rFCSAs of the MF (65.74±21.51 vs. 92.37±21.68; P<0.001), ES (82.67±21.44 vs. 111.48±24.21; P<0.001) and PSE (144.31±36.12 vs. 208.48±41.57; P<0.001) and the HU values of the lumbosacral region (103.80±22.64 vs.. 132.19±19.17; P<0.001) and LIV (111.70±23.23 vs. 128.69±20.70; P=0.005) were significantly lower in the DIP group. Significantly less preoperative pelvic tilt and greater postoperative lumbosacral lordosis and sagittal vertical axis (SVA) values were observed in the DIP group. The rFCSA of the PSE, the HU value of the lumbosacral region, and the postoperative SVA value were detected as independent predictive factors of DIPs. Lower muscularity of the PSE, a lower vBMD of the lumbosacral region, and postoperative sagittal malalignment were independent predictive factors of DIPs. Surgeons should emphasize the preoperative evaluation of paraspinal muscle and bone mass in DLS patients.

Clinical Outcome-Supported Advance of Cement Lumber Interbody Fusion for Degenerative Lumbar Scoliosis

Clinical Outcome-Supported Advance of Cement Lumber Interbody Fusion for Degenerative Lumbar Scoliosis

Evaluation of lumbar stiffness after long-level fusion for degenerative lumbar scoliosis via a Chinese version of the lumbar stiffness disability index

BACKGROUND CONTEXTLong-level spinal fusion for degenerative lumbar scoliosis (DLS)seeks to eliminate spinal motion in an attempt to alleviate pain, improve deformity, and reduce disability. However, this surgery considerably impairs the performance of activities of daily living (ADL) due to the resulting stiffness. The lumbar stiffness disability index (LSDI) is a validated measure of the effect of lumbar stiffness on functional activity, but this index might not be fully applicable to the elderly Chinese population given several specific lifestyle characteristics. PURPOSETo evaluate lumbar stiffness in patients with DLS after long-level fusion by Chinese-LSDI (C-LSDI). STUDY DESIGNA retrospective study. PATIENT SAMPLEA total of 129 DLS patients who underwent long-level (≧4 levels) fusion surgery with at least one-year follow-up from June 2009 to September 2017 were retrospectively included. OUTCOME MEASURESThe C-LSDI was designed by modifying LSDI and Korean-LSDI (K-LSDI) based on elderly Chinese lifestyles and the internal consistency and retest repeatability of the patient-reported outcome questionnaire in the measurement of the impact of lumbar stiffness on functional abilities was assessed. METHODSThe radiographic parameters including Cobb angle, apical vertebral translation (AVT), coronal vertical axis (CVA), sagittal vertical axis (SVA), thoracic kyphosis (TK), thoracolumbar kyphosis (TLK), pelvic tilt (PT), pelvic incidence (PI), sacral slope (SS), lumbar lordosis (LL), and PI-LL, and clinical symptoms including visual analogue scale (VAS) for back and low extremity pain; Oswestry disability index (ODI), Japanese Orthopedic Association-29 (JOA–29), Scoliosis Research Society⁃22 (SRS–22), 36⁃Item short form survey (SF–36), physical component scores (PCS) and mental component scores (MCS) were measured preoperatively and at the last follow-up. RESULTSCompared with LSDI and K-LSDI, the C-LSDI demonstrated higher internal consistency (Cronbach's alpha=0.902) and retest reliability (Internal consistency coefficients, ICC=0.904) in the elderly Chinese population. All patients showed increased lumbar stiffness and significant improvement in pain and deformity postoperatively. Regarding items, such as performing personal hygiene after toileting and getting out of a car, people reported more inconvenience with increasingly fixed levels. CONCLUSIONSThis study demonstrated that the C-LSDI questionnaire was a reliable and valid instrument for assessing functional limitations due to lumbar stiffness among elderly Chinese patients with DLS after long-level fusion. Although the effects of stiffness did trend toward greater impacts among patients who underwent longer fusions, most patients were satisfied with trade-offs of function and pain relief in exchange for perceived increases in lumbar stiffness.

Free-hand technique of S(2) alar iliac screw placement for sacropelvic fusion in lumbar degenerative scoliosis

Objective: To evaluate the feasibility of placement of S(2) alar iliac screw (S(2)AI) using free-hand technique for sacrapelvic fusion in lumbar degenerative scoliosis. Methods: Eighteen patients with Lumbar Degenerative Scoliosis treated by S(2)AI screw fixation at Department of Orthopedics, General Hospital of Southern Theater Command of People's Liberation Army and Department of Orthopedics, 89th hospital of People's Liberation Army from August 2014 to October 2018 were analyzed retrospectively. There were 5 males and 13 females, aged 63.2 years old (range:55 to 71 years old).Parameters of spine including: Cobb Angle, C(7) plumb line -center sacral vertical line (C(7)PL-CSVL), lumbar lordosis(LL), sagittal vertical axis(SVA), pelvic incidence(PI), pelvic tilt(PT), sacral slope (SS) and pI-LL were measured on the whole spine X-ray before operation and at final follow-up. Pelvic CT scan was performed postoperatively to assess the accuracy of S(2)AI placement. Oswestry disability Index (ODI) was also recorded. The data were compared by paired t test or Wilcoxon tests. Results: All patients were followed up for 23.7 months (range: 12~62 months).At the last follow up, Cobb Angle decreased from (32.28±4.97) °preoperative to (6.56±3.20) ° (t=41.142, P<0.01) and C(7)PL-CSVL deceased from (1.11±2.07) cm preoperative to (0.18±1.08) cm (t=41.142, P=0.06) .LL improved from (-22.39±13.07) °preoperative to (-36.39±4.29) ° (t=4.470, P<0.01) , PI-LL decreased from (26.83±14.83)°preoperative to (13.72±8.3)° (t=4.396, P<0.01) , PT decreased from (27.94±4.26) °to (23.39±6.08) ° (t=2.680, P=0.02) , and SS increased from (22.22±6.36) °to (26.28±7.24) ° (t=-2.178, P=0.04) .SVA decreased from (6.54±4.51) cm preoperative to (2.62±1.29) cm (t=3.052, P=0.01) .ODI decreased from 0.58(0.40) (M(Q(R))) to 0.18 (0.15) (Z=-4.567, P<0.01) .No complications such as nerve and blood vessel injury occurred during the operation. A total of 32 S(2)AI screws were placed, 3 screws were placed with mild to moderate cortical breaches, 2 were perforated the pelvis ventrally, 1 was perforated posteriorly, with no clinically notable neurovascular or visceral complications. Eight patients finished the SRS-22 questionnaire, with mean score of 4.4 in terms of satisfaction with management. Conclusions: Free-hand technique of S(2)AI screw placement for sacrapelvic fusion in degenerative lumbar scoliosis is safe and feasible.S(2)AI fixation in DLS can provide great correction of deformity, maintain the stability of lumbo-pelvic area and improve the clinical symptoms.

Sagittal spinopelvic alignment after spinal fusion in degenerative lumbar scoliosis: a meta-analysis

Objective: This meta-analysis aimed to investigate the changes in sagittal spinopelvic alignment in degenerative lumbar scoliosis (DLS) from the preoperative state to the last follow-up.Methods: The MEDLINE via PubMed, Cochrane, Scopus, and Embase databases were searched for studies published between January 2010 and January 2019 evaluating radiological parameters including the coronal Cobb angle, sagittal vertical axis (SVA), thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SS), and pelvic tilt (PT) in DLS. Two authors performed data extraction independently. All discrepancies were resolved by consensus.Results: The 34 studies identified showed significant decreases in overall and subgroup Cobb angles from the preoperative state to the last follow-up. Both overall TK and LL were significantly increased from the preoperative state to the last follow-up. In subgroup analysis, LLs in the long fusion, combined approach, and posterior approach group were significantly increased at the final follow-up, but the LL increase in the short fusion group was not significant at the last follow-up. However, there was no significant change in SVA, PI, SS, and PT from the preoperative state to the last follow-up.Conclusions: A literature review identified 34 studies reporting preoperative and last follow-up data on spinal fusion in DLS. Despite heterogeneity, a limited meta-analysis showed significant improvement in the coronal Cobb angle, TK, and LL after spinal fusion in DLS. A large, randomized clinical trial would be necessary to validate our results.

Risk factors analysis of coronal imbalance after posterior long-level fixation and transforaminal lumbar interbody fusion for degenerative lumbar scoliosis

To explore the risk factors of coronal imbalance after posterior long-level fixation and fusion for degenerative lumbar scoliosis. Retrospectivly analyzed the clinical records of 41 patients with degenerative lumbar scoliosis who had received posterior long-level fixation and fusion with selective transforaminal lumbar interbody fusion (TLIF) accompanied by Ponte osteotomy between August 2011 and July 2016. Patients were divided into imbalance group (group A, 11 cases) and balance group (group B, 30 cases) according to state of coronal imbalance measured at last follow-up. The radiographic parameters at preoperation and last follow-up were measured, and the variance of preoperative and last follow-up parameters were calculated. The radiographic parameters included coronal Cobb angle, coronal balance distance (CBD), apical vertebral translation (AVT), apical vertebral rotation (AVR), Cobb angle of lumbar sacral curve (LSC), and L 5 tilt angle (L 5TA). Univariate analysis was performed for the factors including gender, age, preoperative T value of bone mineral density, number of instrumented vertebra, upper and lower instrumented vertebra, segments of TLIF, decompression, and Ponte osteotomy, as well as the continuous variables of preoperative imaging parameters with significant difference were converted into two-category variables, obtained the influence factors of postoperative coronal imbalance. Multivariate logistic regression analysis was performed to verify the risk factors from the preliminary screened influence factors and the variance of imaging parameters with significant difference between the two groups. The follow-up time of groups A and B was (3.76±1.02) years and (3.56±1.03) years respectively, there was no significant difference between the two groups ( t=0.547, P=0.587). The coronal Cobb angle, AVT, LSC Cobb angle, and L 5TA in group A were significantly higher than those in group B before operation ( P<0.05), and all the imaging parameters in group A were significantly higher than those in group B at last follow-up ( P<0.05). There was no significant difference between the two groups in parameters including the variance of coronal Cobb angle, AVT, and LSC Cobb angle before and after operation ( P>0.05), and there were significant differences between the two groups in parameters including the variance of CBD, L 5TA, and AVR ( P<0.05). Univariate analysis showed that preoperative L 5TA was the influencing factor of postoperative coronal imbalance ( P<0.05). Multivariate logistic regression analysis showed that preoperative L 5TA≥15° was an independent risk factor of postoperative coronal imbalance, and variance of pre- and post-operative AVR was a protective factor. Preoperative L 5TA≥15° is an independent risk factor for coronal imbalance in patients with degenerative lumbar scoliosis after posterior long-level fixation and fusion.

Effectiveness of nano-hydroxyapatite/polyamide-66 Cage in interbody fusion for degenerative lumbar scoliosis

To explore the effectiveness of nano-hydroxyapatite/polyamide-66 (n-HA/PA66) Cage in interbody fusion for degenerative lumbar scoliosis. A retrospective analysis was designed and conducted for 43 patients, who underwent posterior decompression and n-HA/PA66 Cage interbody fusion with correction of deformity between January 2013 and June 2016. Eighteen cases were single-level fusion (single-level group) and 25 cases were double-level fusion (double-level group). There was no significant difference in gender, age, body mass index, direction of convex, degree of apical rotation, fusion level, the number of osteoporotic patients, pre-operative intervertebral height of fusion segments, coronal Cobb angle, visual analogue score (VAS), and modified Oswestry Disability Index (ODI) between 2 groups ( P>0.05). The operation time, intraoperative blood loss, postoperative drainage, hospital stay, and complications of the operation were recorded. Modified ODI, VAS score, and MacNab criteria were adopted to assess clinical outcomes. Radiographic indexes, including intervertebral height of fusion segments, coronal Cobb angle, disc insertion depth, and the bone graft fusion rate, were also evaluated. There was no significant difference in operation time, intraoperative blood loss, postoperative drainage, and hospital stay between 2 groups ( P>0.05). All patients were followed up 18-62 months (mean, 30.9 months). Wound complications, postoperative delirium, and Cage retropulsion occurred in 4 cases (2 cases in single-level group, 2 cases in double-level group), 1 case of single-level group, and 1 case of double-level group, respectively. The intervertebral height of fusion segments after operation significantly improved compared with preoperative ones in both groups ( P<0.05). At last follow-up, the intervertebral height in double-level group was superior to which in single-level group ( P<0.05). The coronal Cobb angles after operation significantly improved compared with preoperative ones ( P<0.05), and no significant difference was found between 2 groups at each time point ( P>0.05). The disc insertion depth showed no significant difference between different time points after operation in 2 groups ( P>0.05) and between 2 groups at each time point after operation ( P>0.05). Bony fusion was obtained in all patients at last follow-up. The VAS score and modified ODI after operation in both groups were superior to those before operation ( P<0.05). The VAS score in double-level group was higher than that in single-level group ( P<0.05) at last follow-up, and no significant difference was found in VAS score and modified ODI between 2 groups at other time points ( P>0.05). According to the MacNab criteria, the excellent and good rates at last follow-up were 94.4% and 84.0% in single-level group and double-level group, respectively. The n-HA/PA66 Cage can effectively restore and maintain the disc height of fusion segment, normal sequence, and biomechanical stability of the spine, and gain favorable effectivenss for degenerative lumbar scoliosis. And double-level fusion is superior to single-level fusion in maintaining disc height of fusion segment.

Bipolar Sealer Device Reduces Blood Loss and Transfusion Requirements in Posterior Spinal Fusion for Degenerative Lumbar Scoliosis: A Randomized Control Trial.

A prospective, randomized, controlled clinical study. To determine the efficacy of bipolar sealer device in reducing perioperative blood loss and transfusions in degenerative lumbar scoliosis patients undergoing primary posterior spinal fusion. It has recently been used successfully in pediatric spine surgery, particularly in idiopathic and neuromuscular deformities. However, there is a dearth of literature on prospective study of the efficacy of bipolar sealer device in reducing perioperative blood loss and transfusions in patients undergoing degenerative lumbar scoliosis surgery. A total of 100 consecutive degenerative lumbar scoliosis patients who had undergone primary decompression and posterior spinal fusion with segmental spinal instrumentation between June 2010 and June 2012 were prospectively randomized into 1 of 2 groups according to whether bipolar sealer device for intraoperative/postoperative blood management was used or not. Demographic distribution, perioperative blood loss, blood transfusion rate, the length of stay, and postoperative complications were analyzed. The operation time was significantly shorter in the study group than in the control group, 223.4 versus 248.9 minutes (P=0.026). There was significantly lower intraoperative estimated blood loss in the bipolar sealer group, 407 versus 696 mL (P=0.000). Of the patients with the use of bipolar sealer device, the mean red blood cell transfusion requirement during hospitalization was significantly less than the control group, 0.4 versus 1.1 U/patient (P=0.003). Furthermore, significant difference existed in allogenic blood transfusion rate between the 2 cohorts. Within the study group (with the use of bipolar sealer device), the entire perioperative allogenic blood transfusion rate was 18.0% compared with 40.0% of the control group (P=0.015). There were no complications related directly to the use of the bipolar sealer. Utilization of a bipolar sealer during correction of lumbar degenerative scoliosis may offer comparable hemostatic effects, without prohibitive cost or adverse drug-related risks.

Applications of the scoliosis width-to-length ratio for guiding selection of the surgical approaches of degenerative lumbar scoliosis.

BackgroundThere does not exist a comprehensive parameter for guiding selection of short or long segment fusion for degenerative lumbar scoliosis (DLS). The aim of our study was to investigate the applications of the width-to-length ratio in guiding selection of the surgical approaches for DLS.MethodsA retrospective analysis was performed of 142 patients with DLS who underwent operative treatments from July 2000 to January 2012. The scoliosis width-to-length ratios were measured and used as a grouping criterion of surgical approaches. The Oswestry disability index (ODI) was used to evaluate the clinical outcomes. Radiological parameters such as Cobb’s angle of main curve, Cobb’s angle of compensatory curve were all measured.ResultsFor patients with width-to-length ratio less than 0.36, the short segment group had better short-term postoperative outcomes with regard to Cobb’s angle of main curve, Cobb’s angle of compensatory curve and ODI scores compared to the long segment group. However, for patients with width-to-length ratio greater than 0.36, the postoperative outcomes for the long segment group were better compared to the short segment group.ConclusionsThe scoliosis width-to-length ratio can provide a comprehensive preoperative assessment of the severity of the DLS and guiding selection of a therapeutic treatment regimen. Further studies with a larger number of samples and longer term of follow up are warranted.

Is It Real Adjacent Segment Pathology by Stress Concentration After Limited Fusion in Degenerative Lumbar Scoliosis?

A retrospective comparative study. To investigate adjacent segment pathology (ASP) after limited lumbar fusion in the treatment of degenerative lumbar scoliosis (DLS). The assessment of appropriate surgical techniques for DLS remains one of the most controversial topics in spinal surgery. So far, there has been no study specifically addressing why ASP shows different patterns with respect to different fusion levels after instrumented lumbar fusion for DLS. Fifty-nine patients were enrolled and divided into 2 groups with respect to the proximal fusion level: group I consisted of 29 patients who underwent fusion below the proximal neutral vertebrae, and group II consisted of 30 patients who underwent fusion to the proximal neutral vertebrae. Clinical and radiological assessments were performed with an average of 59.4 months of follow-up. The number of radiological findings for ASP was determined on the basis of a 7-point scale that gave 1 point for each radiological finding. The 2 groups were analyzed according to radiological ASP (RASP). The Oswestry Disability Index and visual analogue scale scores were recorded prospectively. Overall, RASP developed in 16 (27.1%) patients. In group I, 12 (41.4%) of 29 patients, and in group II, 4 (13.3%) of 30 patients showed RASP. Group I yielded an average of 4.5 points, and group II, 1.8 points. RASP scores were much higher in group I than in group II, with statistical significance (P = 0.000). In group I, 4 patients underwent revision surgery, but in group II, only 1 patient did so. RASP displayed variance according to different fusion levels. RASP in group I showed similar patterns to the natural progression of DLS. It is suggested that fusion be included at least at the proximal neutral vertebrae to reduce RASP although RASP with different patterns is unavoidable. 4.

Correlation of Adjacent Segmental Disease with Tilt Angles of the Upper and Lower Instrumented Vertebra in the Degenerative Lumbar Scoliosis

Study Design: Retrospective study. Objectives: To evaluate the correlation of adjacent segmental disease with tilt angles of the upper and lower instrumented vertebra after instrumented posterolateral fusion for degenerative lumbar scoliosis. Summary of Literature Review: There has been no study of radiologic measurement and decision of fusion level using the angle of pedicle screws inserted for treatment of degenerative lumbar scoliosis. Materials and Methods: From 2004 to 2008, 74 patients that underwent decompression and posterolateral fusion for degenerative lumbar scoliosis were included in this study. In all cases, instrumentation and posterolateral fusion were both performed. The sex ratio was 31:43, the mean age was 68.7 years and the mean follow up duration was 37.4 months. The angle between each upper end plate of the upper vertebral body and lower end plate of the lower vertebral body of the fusion, and the line parallel to the axis of the sagittal line of vertebrae was each defined as UIV-a and LIV-b. The correlation of development of adjacent segment disease and UIV-a, and LIV-b angle was investigated. Results: Sum of the absolute value of UIV-a and LIV-b had a statistically significant positive correlation with that of adjacent segment disease. Also, UIV-a alone, had a statistically positive correlation with the development of proximal adjacent segment disease. Conclusions: Since it is proven that adjacent segment disease has positive correlation with the sum of the absolute value of UIV-a and LIV-b, the extent of fusion should be adjusted to make the line parallel to the line perpendicular to the sagittal surface.

Degenerative lumbar scoliosis in elderly patients: dynamic stabilization without fusion versus posterior instrumented fusion

Background contextPosterolateral fusion with pedicle screw instrumentation is currently the most widely accepted technique for degenerative lumbar scoliosis in elderly patients. However, a high incidence of complications has been reported in most series. Dynamic stabilization without fusion in patients older than 60 years has not previously been compared with the use of posterior fusion in degenerative lumbar scoliosis. PurposeTo compare dynamic stabilization without fusion and posterior instrumented fusion in the treatment of degenerative lumbar scoliosis in elderly patients, in terms of perioperative findings, clinical outcomes, and adverse events. Study designA retrospective study. Patient sampleFifty-seven elderly patients were included. There were 45 women (78%) and 12 men (22%) with a mean age of 68.1 years (range, 61–78 years). All patients had degenerative de novo lumbar scoliosis, associated with vertebral canal stenosis in 51 cases (89.4%) and degenerative spondylolisthesis in 24 patients (42.1%). Outcome measuresClinical (Oswestry Disability Index, visual analog scale, Roland-Morris Disability Questionnaire) and radiological (scoliosis and lordosis corrections) outcomes as well as incidence of complications. MethodsPatients were divided into two groups: 32 patients (dynamic group) had dynamic stabilization without fusion and 25 patients (fusion group) underwent posterior instrumented fusion. All the patients' medical records and X-rays were reviewed. Preoperative, postoperative, and follow-up questionnaires were obtained to evaluate clinical outcomes. ResultsAt an average follow-up of 64 months (range, 42–90 months), clinical results improved similarly in both groups of patients. Statistically superior scoliosis and final lordosis corrections were achieved with posterior fusion (56.9% vs. 37.3% and −46.8° vs. −35.8°, respectively). However, in the dynamic group, incidence of overall complications was lower (25% vs. 44%), and fewer patients required revision surgery (6.2% vs. 16%). Furthermore, lower average values of operative duration (190 vs. 240 minutes) and blood loss (950 vs. 1,400 cc) were observed in the dynamic group than in the fusion group. ConclusionsIn elderly patients with degenerative lumbar scoliosis, pedicle screw–based dynamic stabilization was less invasive with shorter operative duration, less blood loss, and lower adverse event rates than instrumented posterior fusion. Scoliosis curve reduction and lumbar lordosis were superior after fusion; however, dynamic stabilization achieved satisfying values of both these parameters, and these results were stable after an average follow-up of more than 5 years. Furthermore, there was no difference between the two techniques in terms of functional clinical outcomes at the last follow-up.

Risk Factors of Sagittal Decompensation After Long Posterior Instrumentation and Fusion for Degenerative Lumbar Scoliosis

A retrospective study of clinical results of operative treatment for degenerative lumbar scoliosis. To determine the risk factors of sagittal decompensation after long instrumentation and fusion to L5 or S1. Little is known about the risk factors for sagittal decompensation, which was defined in this study as sagittal C7 plumb falling anterior >8 cm from the posterosuperior corner of the sacrum. Forty-five patients (mean age: 64.4 year) with adult degenerative lumbar scoliosis were reviewed retrospectively with a minimum 2 years. The mean number of levels fused was 6.1 +/- 1.6 segments. The upper instrumented vertebra ranged from T9 to L2. The lower instrumented vertebra was L5 and S1 in 24 and 21 patients, respectively. Sagittal decompensation (SD) developed in 19 patients. The most significant risk factors of SD were preoperative sagittal imbalance and high pelvic incidence. The preoperative sagittal C7 plumb was more positive (67.9 mm) in the decompensation group than in the balance group (37.0 mm) (P = 0.002). There was a significant difference in pelvic incidence between 61.7 degrees in the decompensation and 54.9 degrees in the balance group (P = 0.01). The preoperative lumbar lordosis was hypolordotic in the decompensation group, however, it was not found to be a risk factor. Pseudarthrosis was identified at the lumbosacral junction in 5 patients, and 4 of them (80%) had SD. SD developed in 55% of patients who had loosening of the distal screws and 50% of patients with hypolordotic lumbar fusion. Distal adjacent segment disease was more likely to cause SD than proximal adjacent segment disease. Sagittal decompensation is common after long posterior instrumentation and fusion for degenerative lumbar scoliosis. It is mostly associated with complications at the distal segments, including pseudarthrosis and implant failure at the lumbosacral junction. Restoration of optimal lumbar lordosis and secure lumbosacral fixation is necessary especially in patients with preoperative sagittal imbalance and high pelvic incidence in order to prevent sagittal decompensation after surgery.

Healos graft carrier with bone marrow aspirate instead of allograft as adjunct to local autograft for posterolateral fusion in degenerative lumbar scoliosis: a minimum 2-year follow-up study

The objective of this study was to examine the efficacy and safety of Healos graft carrier with bone marrow aspirate and local autograft compared with the results of allograft in patients with lumbar degenerative scoliosis undergoing posterolateral fusion. Twenty-eight patients with degenerative scoliosis underwent posterolateral instrumented fusion and decompression. Patients were grouped according to the graft used. Group A consisted of 12 cases in which the authors used a Healos graft carrier, bone marrow aspirate, and local autograft, and Group B consisted of 16 cases in which the authors used cancellous allograft and local autograft. Patients were followed for a minimum of 2 years postoperatively in terms of pain (visual analog scale), function (Oswestry Disability Index), curve magnitude (Cobb angle), and fusion status (plain and dynamic radiographs). The 2 groups did not differ statistically significantly (p > 0.05) in age, sex, smoking habits, magnitude of preoperative visual analog scale score, Oswestry Disability Index score, Cobb angle, or number of levels requiring decompression and fusion. The groups had similar (p > 0.05) results in terms of pain, function, curve progression, and fusion rates at the 2-year follow-up examination. Radiographic fusion was achieved in all but 2 cases, 1 in each group, in which the patients were asymptomatic. Patients in the allograft group (Group B) showed evidence of fusion earlier than in the Healos group (p < 0.05). No toxicity from Healos graft was recorded. The combination of Healos hydroxyapatite sponge and bone marrow aspirate plus local allograft had significantly slower fusion rates but equal clinical outcomes compared with cancellous allograft plus local autograft when used for posterolateral fusion in patients with degenerative lumbar scoliosis.

Dynamic Stabilization for Degenerative Lumbar Scoliosis in Elderly Patients

A retrospective study. To analyze outcomes after dynamic stabilization without fusion in degenerative lumbar scoliosis in elderly patients. Frequent complications of posterolateral instrumented fusion have been reported after treatment of degenerative lumbar scoliosis in elderly patients. The use of dynamic stabilization without fusion can be advocated to reduce such adverse effects, being less invasive, with shorter operation time and less blood loss. No study in the literature has analyzed outcomes of dynamic stabilization without fusion in these degenerative deformities. Twenty-nine elderly patients (average age, 68.5 years; range, 61-78) with degenerative lumbar scoliosis, undergoing dynamic stabilization (Dynesys system) without fusion combined with decompressive laminectomy, in cases with associated stenosis, were analyzed. Stenosis of the vertebral canal was associated in 27 patients (93.1%); 13 cases (44.8%) also presented a degenerative spondylolisthesis. An independent spine surgeon retrospectively reviewed all the patients' medical records and radiographs to assess operative data and surgery-related complications. Preoperative, postoperative, and follow-up questionnaires were obtained to evaluate clinical outcomes. The mean follow-up time was 54 months (range, 39-68). Oswestry Disability Index, Roland Morris Disability Questionnaire, and back pain and leg pain visual analogue scale scores received a statistically significant improvement at last control; the mean improvement was 51.6% for Oswestry Disability Index (P = 0.01), 58.2% for Roland Morris Disability Questionnaire (P = 0.01), 51.7% for leg pain (P = 0.02), and 57.8% for back pain (P = 0.01). Radiographically, degenerative scoliosis and associated spondylolisthesis resulted stable at follow-up with a moderate correction: the average scoliosis Cobb angle was 16.9 degrees (range, 12 degrees -37 degrees) before surgery and 11.1 degrees (range, 4 degrees -26 degrees) at last follow-up, with a 37.5% mean correction (P = 0.01); the anterior vertebral translation was 18.9% (range, 12%-27%) before surgery and 17% (range, 0%-27%) at follow-up, for a 14.6% mean correction (range, 0%-100%) (P = 0.02). No implant-related complications (screw loosening or breakage) or loss of correction were observed. Four cases (13.8%) presented an asymptomatic radiolucent line around screws of the S1 level without screw loosening. Six patients (20.7%) showed minor complications (ileus in 2 cases, urinary tract infection in 2, transient postoperative delirium in one, and respiratory difficulties after surgery in another patient). In 2 other patients (6.8%) incurred major complications, both requiring a revision surgery, for a misplaced screw on L5 and junctional disc degeneration at the lower level respectively. No neurologic complications occurred. Dynamic stabilization with pedicle screws in addition to decompressive laminectomy resulted a safe procedure in elderly patients with degenerative lumbar scoliosis; it was able to maintain enough stability to prevent progression of scoliosis and instability, enabling a wide laminectomy in cases of associated lumbar stenosis. This nonfusion stabilization technique was less aggressive than instrumented fusion and obtained a statistically significant improvement of the clinical outcome at last follow-up.

Arthrodesis to L5 versus S1 in long instrumentation and fusion for degenerative lumbar scoliosis

There is a debate regarding the distal fusion level for degenerative lumbar scoliosis. Whether a healthy L5-S1 motion segment should be included or not in the fusion remains controversial. The purpose of this study was to determine the optimal indication for the fusion to the sacrum, and to compare the results of distal fusion to L5 versus the sacrum in the long instrumented fusion for degenerative lumbar scoliosis. A total of 45 patients who had undergone long instrumentation and fusion for degenerative lumbar scoliosis were evaluated with a minimum 2 year follow-up. Twenty-four patients (mean age 63.6) underwent fusion to L5 and 21 patients (mean age 65.6) underwent fusion to the sacrum. Supplemental interbody fusion was performed in 12 patients in the L5 group and eleven patients in the sacrum group. The number of levels fused was 6.08 segments (range 4-8) in the L5 group and 6.09 (range 4-9) in the sacrum group. Intraoperative blood loss (2,754 ml versus 2,938 ml) and operative time (220 min versus 229 min) were similar in both groups. The Cobb angle changed from 24.7 degrees before surgery to 6.8 degrees after surgery in the L5 group, and from 22.8 degrees to 7.7 degrees in the sacrum group without statistical difference. Correction of lumbar lordosis was statistically better in the sacrum group (P = 0.03). Less correction of lumbar lordosis in the L5 group seemed to be associated with subsequent advanced L5-S1 disc degeneration. The change of coronal and sagittal imbalance was not different in both groups. Subsequent advanced L5-S1 disc degeneration occurred in 58% of the patients in the L5 group. Symptomatic adjacent segment disease at L5-S1 developed in five patients. Interestingly, the development of adjacent segment disease was not related to the preoperative grade of disc degeneration, which proved minimal degeneration in the five patients. In the L5 group, there were nine patients of complications at L5-S1 segment, including adjacent segment disease at L5-S1 and loosening of L5 screws. Seven of the nine patients showed preoperative sagittal imbalance and/or lumbar hypolordosis, which might be risk factors of complications at L5-S1. For the patients with sagittal imbalance and lumbar hypolordosis, L5-S1 should be included in the fusion even if L5-S1 disc was minimal degeneration.

Proximal Adjacent Segment Disease following Posterior Instrumentation and Fusion for Degenerative Lumbar Scoliosis

Purpose: Adjacent segment disease (ASD) is major complication following spinal instrumentation and fusion. The purpose of the current study was to determine the prevalence and risk factors of proximal ASD following posterior instrumentation and fusion for degenerative lumbar scoliosis. Materials and Methods: Seventy-two patients (mean age 64.8 years) who had undergone decompression and fusion with pedicle screw instrumentation were evaluated. The average follow-up was 4.7 years. Twenty-five patients had additional interbody fusion at the lower lumbar spine. The average number of levels fused was 5.1 segments (range 1-9). The upper instrumented vertebrae ranged from T9 to L4. The lower instrumented vertebrae were L5 and S1. Results: Proximal ASD developed in 17 (24%) of 72 patients, including compression fractures (n=6), junctional kyphosis (n=5), spinal stenosis (n=4), and symptomatic disc collapse (n=2). The preoperative scoliotic angle, lumbar lordosis, thoracic kyphosis, and coronal and sagittal C7 plumb were not associated with the development of proximal ASD. There was a close correlation between the level of the upper instrumented vertebrae and the development of ASD (p=0.001). When fusion did not extend beyond the lumbar vertebra, ASD occurred in 15 (38.5%) of 39 patients. In contrast, when fusion extended up to the thoracic vertebrae, ASD occurred in 2 (6.1%) of 33 patients. The improvement in the Oswestry score was superior to the group without ASD (p=0.001). Conclusion: The prevalence of symptomatic ASD at the proximal segment was 24% after posterior instrumentation and fusion for degenerative lumbar scoliosis. The cephalad extent of fusion was the most significant risk factor for the development of proximal ASD.