Improvement In Sagittal Balance Research Articles

Use of Dynamic Spinal Instruments (Dynesys) in Adult Spinal Deformities According to Silva-Lenke and Berjano-Lamartina Classifications.

Adult spinal deformities (ASD) present complex challenges in spine surgery. The diverse nature of these deformities requires a comprehensive understanding of their classification and treatment options. Traditional approaches, such as fusion and rigid stabilization are associated with complications, including screw loosening, breakage, proximal junctional kyphosis (PJK), and pseudoarthrosis. Dynamic stabilization techniques have emerged as promising alternatives, to reduce these complications and preserve spinal motion. This study investigated the effectiveness of dynamic stabilization using the Dynesys system in the surgical treatment of adult degenerative spinal deformities, with a particular emphasis on their classification. ASDs were classified according to the Berjano-Lamartina (BL) and Silva-Lenke (SL) classifications. We analyzed the efficacy of the Dynesys system in enhancing sagittal balance, radiological parameters, and clinical outcomes in this context. Dynamic stabilization of patients with ASDs using the Dynesys system significantly improved the visual analog scale and Oswestry Disability Index scores and decreased the complication rates. Patients with BL types 2, 3, and 4 experienced a significant improvement in sagittal balance followed by sagittal vertical axis measurements (p = 0.045, p = 0.015, and p < 0.0001, respectively). The SL and BL classifications, which were originally developed for rigid spinal stabilization, can be applied in dynamic stabilization. Furthermore, dynamic stabilization using the Dynesys system can be used as an alternative to rigid stabilization in SL levels 2 and 3, and BL types 1, 2, and 3, and in some patients with type 4 ASDs.

High Degree Spondylolisthesis in Adults: Monosegmental Reduction and Fixation in Our Perspective

Objective: To evaluate a method to reduce high degree spondylolisthesis in adults with monosegmental fixing preserving the adjacent level and the improvement of sagittal balance. Methods: A prospective study, with 8 adult patients with high degree spondy\olisthesis (III and IV) in adults who underwent surgery by the same team. We included 5 women and 3 men with a mean age of 37 years that had no improvement with conservative treatment. The surgical technique used was total or partial reduction by Spondylolisthesis Reduction Instrument SRI System. Results: The L5-S1 level was involved in five patients, L4-L5 in two and VT-S1 in one patient. Isthmic type predominated in five patients, followed by dysplastic type in two and one a-spondytolisthesis. These patients were assessed by the Oswestry scale. Which showed a preoperative average of 59% and postoperative average of 12.4%. Conclusion: The method of high- grade spondylolisthesis reduction with instrumentation only at the affected level is a treatment option with good results, with control of the pain profile and functional improvement in patients.

Systematic Review and Meta-Analysis of 3 Treatment Arms for Vertebral Compression Fractures: A Comparison of Improvement in Pain, Adjacent-Level Fractures, and Quality of Life Between Vertebroplasty, Kyphoplasty, and Nonoperative Management.

Osteoporotic vertebral fractures (OVFs) have become increasingly common, and previous nonrandomized and randomized controlled trials (RCTs) have compared the effects of cement augmentation versus nonoperative management on the clinical outcome. This meta-analysis focuses on RCTs and the calculated differences between cement augmentation techniques and nonsurgical management in outcome (e.g., pain reduction, adjacent-level fractures, and quality of life [QOL]). A systematic review was performed according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, and the following scientific search engines were used: MEDLINE, Embase, Cochrane, Web of Science, and Scopus. The inclusion criteria included RCTs that addressed different treatment strategies for OVF. The primary outcome was pain, which was determined by a visual analog scale (VAS) score; the secondary outcomes were the risk of adjacent-level fractures and QOL (as determined by the EuroQol-5 Dimension [EQ-5D] questionnaire, the Oswestry Disability Index [ODI], the Quality of Life Questionnaire of the European Foundation for Osteoporosis [QUALEFFO], and the Roland-Morris Disability Questionnaire [RDQ]). Patients were assigned to 3 groups according to their treatment: vertebroplasty (VP), kyphoplasty (KP), and nonoperative management (NOM). The short-term (weeks), midterm (months), and long-term (>1 year) effects were compared. A random effects model was used to summarize the treatment effect, including I2 for assessing heterogeneity and the revised Cochrane risk-of-bias 2 (RoB 2) tool for assessment of ROB. Funnel plots were used to assess risk of publication bias. The log of the odds ratio (OR) between treatments is reported. After screening of 1,861 references, 53 underwent full-text analysis and 16 trials (30.2%) were included. Eleven trials (68.8%) compared VP and NOM, 1 (6.3%) compared KP and NOM, and 4 (25.0%) compared KP and VP. Improvement of pain was better by 1.31 points (95% confidence interval [CI], 0.41 to 2.21; p < 0.001) after VP when compared with NOM in short-term follow-up. Pain effects were similar after VP and KP (midterm difference of 0.0 points; 95% CI, -0.25 to 0.25). The risk of adjacent-level fractures was not increased after any treatment (log OR, -0.16; 95% CI, -0.83 to 0.5; NOM vs. VP or KP). QOL did not differ significantly between the VP or KP and NOM groups except in the short term when measured by the RDQ. This meta-analysis provides evidence in favor of the surgical treatment of OVFs. Surgery was associated with greater improvement of pain and was unrelated to the development of adjacent-level fractures or QOL. Although improvements in sagittal balance after surgery were poorly documented, surgical treatment may be warranted if pain is a relevant problem. Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Association Between Paravertebral Muscle Mass and Improvement in Sagittal Imbalance After Decompression Surgery of Lumbar Spinal Stenosis.

Retrospective observational study. This study examined associated factors for the improvement in spinal imbalance following decompression surgery without fusion. Several reports have suggested that decompression surgery without fusion may have a beneficial effect on sagittal balance in patients with lumbar spinal stenosis (LSS) through their postoperative course. However, few reports have examined the association between an improvement in sagittal imbalance and spinal sarcopenia. We retrospectively reviewed 92 patients with LSS and a preoperative sagittal vertical axis (SVA) more than or equal to 40 mm who underwent decompression surgery without fusion at a single institution between April 2017 and October 2018. Patients' background and radiograph parameters and the status of spinal sarcopenia, defined using the relative cross-sectional area (rCSA) of the paravertebral muscle (PVM) and psoas muscle at the L4 caudal endplate level, were assessed. We divided the patients into two groups: those with a postoperative SVA less than 40 mm (balanced group) and those with a postoperative SVA more than or equal to 40 mm (imbalanced group). We then compared the variables between the two groups. A total of 29 (31.5%) patients obtained an improved sagittal imbalance after decompression surgery. The rCSA-PVM in the balanced group was significantly higher than that in the imbalanced group (P = 0.042). The preoperative pelvic incidence (PI)-lumbar lordosis (LL) mismatch (P = 0.048) and the proportion with compression vertebral fracture (P = 0.028) in the balanced group were significantly lower than those in the imbalanced group. A multivariate logistic regression analysis identified PI-LL less than or equal to 10° and rCSA-PVM more than or equal to 2.5 as significant associated factor for the improvement in spinal imbalance following decompression surgery. A larger volume of paravertebral muscles and a lower PI-LL were associated with an improvement in sagittal balance in patients with LSS who underwent decompression surgery.Level of Evidence: 3.

221. Change in sagittal alignment after decompression alone in patients with lumbar spinal stenosis: a prospective cohort study

BACKGROUND CONTEXT Patients with lumbar spinal stenosis present with low back pain, numbness and pain in the legs and gait difficulties due to neurogenic claudication. Patients often walk in a stooped posture to increase the spinal canal diameter by stretching out the ligamentum flavum. This stooped posture leads to a positive sagittal balance. After decompressive surgery, patients may walk in a less stooped manner, improving their sagittal balance, which may lead to less back pain and improved patient reported outcomes. PURPOSE To determine if sagittal balance will improve in patients with spinal stenosis after decompression alone. STUDY DESIGN/SETTING Prospective longitudinal cohort study. PATIENT SAMPLE Patients with lumbar spinal stenosis who underwent decompression alone. OUTCOME MEASURES Oswestry Disability Index (ODI), visual analogue scale (VAS)- leg and back pain. METHODS This study compares preoperative and 6-month postoperative full-length 36” standing lateral and posterior-anterior x-rays and 1-year Oswestry Disability Index (ODI), visual analogue scale (VAS)- leg and back pain, in patients undergoing decompression alone without fusion for central or combined central and lateral stenosis, in patients 60 years and older from March 2016 until September 2017. The following radiographic parameters were measured coronal cobb angle (COBB), pelvic incidence (PI), sagittal vertical axis (SVA), lumbar lordosis (LL), pelvic tilt (PT), pelvic incidence-lumbar lordosis ratio (PI-LL) and sacral slope (SS). RESULTS Forty-five patients (24 males and 21 females) were included. Patients had symptoms for more than 3 months at the time of surgery. Most patients were operated with a bilateral laminectomy over two levels. Sagittal balance showed a statistically significant change in SVA from 65.0mm to 48.6mm (p=0.009) and PI-LL mismatch 7.80 to 4.24 (p= 0.005). A small to moderate association was found between SVA and ODI both preoperatively (r=0.54, p= 0.001) and postoperatively (r=0.51, p= 0.001) and preoperative VAS-leg/back pain (r=0.60, p=0.001)/(r=0.42,p=0.009). CONCLUSIONS There is a statistically significant improvement in sagittal balance in patients undergoing decompression alone for lumbar spinal stenosis. Associations between the SVA and ODI and VAS-leg/back pain indicate that improvements in sagittal balance contribute to improvements in patient reported outcomes. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Prospective Evaluation of Spino-Pelvic Parameters with Clinical Correlation in Patients Operated with an Anterior Lumbar Interbody Fusion.

Study DesignProspective study.PurposeThe goal of this study was to evaluate the impact of anterior lumbar interbody fusion (ALIF) on L5–S1 level for restitution of distal segmental lordosis and to investigate its consequences on spino-pelvic parameters and the global sagittal balance.Overview of LiteratureLumbar surgery must be adapted to the spinal morphology in order to restore an adequate relation between pelvic and spinal parameters and especially to the pelvic incidence.MethodsAn observational, prospective study was conducted between January 2013 and May 2017. Eighty-six patients were treated by L5–S1 ALIF procedure regardless of disc replacement above L5–S1 level. Thirty-seven patients were included and subset analyses were performed on 25 patients operated on an isolated ALIF L5–S1 (group 1), and 12 patients with hybrid surgery consisting of an L5– S1 ALIF procedure and a L4–L5 lumbar disc replacement (group 2). Clinical parameters were analyzed using Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) at M0 (preoperative) and M12 (12 months). Lumbo-pelvic parameters were assessed on a standingfull-spine X-ray, preoperatively and at M12 after surgery.ResultsWe observed a significant evolution of L1–S1 lumbar lordosis (p <0.001) with a significant increase of the distal arch L4–S1 lordosis (p <0.001) and decrease of the proximal arch lordosis (p =0.03). Preoperatively, 27% of the patients were unbalanced. Significant variation in sagittal balance parameters was observed, with a decrease of the sagittal vertebral axis (p <0.001). VAS and ODI improved significantly but no correlation was found. An evolution in the same direction was found in the two subgroup analyses.ConclusionsALIF procedure on L5–S1 level allowed a reconstruction of lumbosacral segmental lordosis, modification of global lordosis, without variation of spino-pelvic parameters except an improvement in sagittal balance.

Biomechanical implications of unilateral facetectomy, unilateral facetectomy plus partial contralateral facetectomy, and complete bilateral facetectomy in minimally invasive transforaminal interbody fusion.

Minimally invasive transforaminal interbody fusion techniques vary among surgeons. One decision point is whether to perform a unilateral facetectomy (UF), a unilateral facetectomy plus partial contralateral facetectomy (UF/PF), or a complete bilateral facetectomy (CBF). The authors therefore compared the biomechanical benefits of all 3 types of facetectomies to determine which approach produces improved biomechanical outcomes. Seven human cadaveric specimens (L3-S1) were potted and prepped for UF, with full facet removal, hemilaminectomy, discectomy, and pedicle screw placement. After distraction, a fixed interbody spacer was placed, and compression was performed. A final fixation configuration was performed by locking the rods across the screws posteriorly with bilateral compression. Final lordosis angle and change and foraminal height were measured, and standard nondestructive flexibility tests were performed to assess intervertebral range of motion (ROM) and compressive stiffness. The same procedure was followed for UF/PF and CBF in all 7 specimens. All 3 conditions demonstrated similar ROM and compressive stiffness. No statistically significant differences occurred with distraction, but CBF demonstrated significantly greater change than UF in mean foraminal height after bilateral posterior compression (1.90 ± 0.62 vs 1.00 ± 0.45 mm, respectively, p = 0.04). With compression, the CBF demonstrated significantly greater mean ROM than the UF (2.82° ± 0.83° vs 2.170° ± 1.10°, p = 0.007). The final lordosis angle was greatest with CBF (3.74° ± 0.70°) and lowest with UF (2.68° ± 1.28°). This finding was statistically significant across all 3 conditions (p ≤ 0.04). Although UF/PF and CBF may require slightly more time and effort and incur more risk than UF, the potential improvement in sagittal balance may be worthwhile for select patients.

Relationship Between Sagittal Balance and Axial Symptoms in Patients with Cervical Spondylotic Myelopathy Treated with Anterior Cervical Discectomy and Fusion

Purpose: The purpose of this study was to investigate the sagittal balance of the cervical spine and the clinical outcomes of anterior cervical discectomy and fusion (ACDF) for the treatment of cervical spondylotic myelopathy and to explore whether sagittal balance is related to the incidence of postoperative axial symptoms. Methods: Sixty-seven consecutive patients who underwent ACDF for the treatment of cervical spondylotic myelopathy from January 2014 to December 2016 were enrolled in our study. Sagittal balance parameters (global lordotic angle, segmented lordotic angle, T1 slope, and C2–7 sagittal vertical axis [C2–7 SVA] were recorded in the preoperative period and at 1 month, 3 months, and 1 year postoperatively. Clinical outcomes (JOA and NDI scores) and incidence of axial symptoms were also evaluated before and after surgery. Subgroup analysis included 20 patients with preoperative abnormal sagittal balance group (C2–7 SVA larger than 20 mm), and these patients were divided into two groups, namely axial symptom group and nonaxial symptom group. Result: The sagittal balance parameters (global lordotic angle, segmented lordotic angle, and TI slope) and the clinical outcomes after surgery significantly improved. The subgroup analysis within the preoperative abnormal sagittal balance group showed significant differences in postoperative and change in C2–7 SVA between patients with and without postoperative axial symptoms. Conclusion: ACDF can be applied to restore the sagittal alignment of the cervical spine and effectively improve clinical outcomes for the treatment of cervical spondylotic myelopathy. Sagittal balance improvement may be associated with the low incidence of postoperative axial symptoms for patients with abnormal cervical sagittal balance before surgery.

Improvement in Sagittal Balance After Decompression Surgery without Fusion in Patients with Degenerative Lumbar Stenosis: Clinical and Radiographic Results at 1 Year.

To evaluate modifications in static spinal status after posterior decompression surgery without fusion in patients with symptomatic central canal stenosis. From November 2014 to May 2016, 72 patients who underwent isolated decompression for lumbar spinal stenosis were enrolled prospectively in this single-center study. All of the patients had lateral full-body x-ray scans with the EOS system (EOS Imaging, Paris, France) before surgery and after 12 months of follow-up. Patients were classified into 3 groups according to their preoperative sagittal vertical axis (<50 mm, ≥50 mm, and <100 mm, ≥100 mm). SVA decreased significantly (SVA preoperative: 72.3 ± 43.1; SVA postoperative: 48.3 ± 46.8. P < 0.001). Lumbar lordosis increased significantly from 41.9 ± 13.4 in the preoperative period to 46.5 ± 14.8 at the last follow-up (P < 0.001). In the imbalance groups, the mean postoperative SVA decreased significantly compared with preoperative SVA (P= 0.004). Surgery led to a significant increase in lumbar lordosis in the 3 groups (P < 0.05). Nonetheless, a certain degree of residual imbalance persisted in the major imbalance group. In all of the groups, decompression surgery led to a significant improvement in clinical scores (P < 0.05). Our study showed an improvement in sagittal balance and lumbar lordosis after decompression surgery without fusion, even in patients with a preoperative SVA >100 mm. However, a certain degree of sagittal imbalance may persist after surgery in patients with major initial imbalance (SVA >100 mm). Nonetheless, after surgery, these patients experienced a clinical benefit comparable with that in the other groups.

Posterior-Only Vertebral Column Resection for Fused Spondyloptosis

Study DesignRetrospective review. ObjectivesTo describe 3 cases of a posterior-only vertebral column resection (pVCR) for the treatment of spondyloptosis in the setting of prior spinal fusions. Summary of Background DataLumbosacral spondyloptosis is a rare spinal deformity with a number of surgical options, none of which demonstrate clear superiority. The use of an L5 vertebral column resection, via combined anterior and posterior approaches, to restore lumbosacral alignment has been described though is accompanied by high rates of neurological deficit. MethodsReview of 3 cases of spondyloptosis with prior spinal fusions in which a staged pVCR was used for deformity reconstruction. ResultsThree females, ages 39, 54, and 28, developed spondyloptosis with progressive lumbosacral kyphosis and sagittal malalignment after prior in-situ posterolateral spinal fusions. All were treated with staged pVCRs. At ultimate follow-up, imaging revealed improvement in sagittal balance of 6.1 cm (56%) in the 39-year-old and 12 cm (67%) in the 54-year-old, 21.1 cm (92%) in the 28-year-old. All patients had improvement in outcome scores with perfect satisfaction scores despite the 54-year-old having a persistent right foot drop. ConclusionPosterior-only VCR for spondyloptosis is a technically demanding surgical option offering significant radiographic and clinical improvement, but carries a risk for L5 nerve root deficit as in any spondyloptosis treatment.

Analysis of Sagittal Parameters in Patients Undergoing One- or Two-Level Closing Wedge Osteotomy for Correcting Thoracolumbar Kyphosis Secondary to Ankylosing Spondylitis.

Retrospective analysis of clinical records. To assess and compare the improvement in sagittal balance after one- or two-level closing wedge osteotomy for correcting thoracolumbar kyphosis secondary to ankylosing spondylitis (AS). Closing wedge osteotomy represents a common approach to correct kyphosis in AS. Although several reports have described the outcomes of one- or two-level closing wedge osteotomy in terms of sagittal parameters, data comparing the outcomes of these procedures are scarce. Between January 2010 and December 2014, 22 patients with AS underwent closing wedge osteotomy (one-level, 12 patients; two-level, 10 patients) for correcting thoracolumbar kyphosis (mean follow-up, 24.8 months; range, 12-60 months). Preoperative and postoperative chin-brow vertical angle, and the sagittal parameters of the vertebral osteotomy segment were documented and compared. Perioperative and postoperative complications were also recorded. The chin-brow vertical angle improved significantly, from 55.0° ± 27.3° to 4.7° ± 4.9° and from 38.2° ± 14.9° to 3.2° ± 5.4° in the one-level and two-level groups, respectively. The total correction (thoracic kyphosis and lumbar lordosis) was 32.8° ± 18.2° and 53.7° ± 9.4° in the one-level and two-level groups, respectively. No death, complete paralysis, or vascular complications occurred during the procedure, but cerebrospinal fluid leak was noted in one and two patients from the one-level and two-level groups, respectively. A distal pedicle screw adjacent to the osteotomy segment became loose during surgery in one patient (one-level group). Postoperatively, no transient neurological deficit, infection, delay union, or loosening or breaking of the internal fixation devices was observed. Osteotomy site fusion was achieved in all patients, and the Oswestry Disability Index scores improved significantly. Closing wedge osteotomy is effective and safe for correcting thoracolumbar kyphosis in patients with AS. Significant correction and improvement in all sagittal parameters were noted in both groups, but two-level closing wedge osteotomy provided better correction. 3.

PSO without neuromonitoring: analysis of peri-op complication rate after lumbar pedicle subtraction osteotomy in adults.

A decompensated sagittal imbalance has been associated with worsening health-related quality of life outcomes and increasing pain. Significant improvement in sagittal balance can be achieved using a pedicle subtraction osteotomy (PSO); however, this procedure has a high complication profile. A lumbar PSO has the advantages of direct visualization of all neural structures and safer retraction of the thecal sac. Sacrificing neuromonitoring may reduce anaesthesia time and lead to improved cost effectiveness of the surgery. However, there are no studies analyzing the complication rate of lumbar PSO without the use of neuromonitoring. We hypothesize that the neurologic complication rate remains comparable to published studies even without the use of intraoperative neuromonitoring. The medical records of all patients of a single institution who received a lumbar PSO for sagittal imbalance between July 2012 and June 2014 were retrospectively analyzed. All surgeries were performed by the first author and without the use of intraoperative neuromonitoring. We analyzed the 30-day complication rate. Twenty-two patients were included in this study. The average age at surgery was 67years. 16 patients had at least one previous lumbar surgery. The average fusion length was seven segments. All patients were instrumented to the sacrum and 19 patients additionally received spinopelvic instrumentation. The average amount of focal correction was 28°. The average surgical time was 362min and blood loss was 2302mL. A total of eight patients with complications were identified. There was a new neurologic postoperative deficit in two patients presenting as a foot drop. Five patients had an unplanned revision surgery. Historically, PSOs are associated with a high surgical complication rate and our results show comparable outcomes and complications to those previously reported. In our series, the absence of neuromonitoring in lumbar PSOs does not appear to increase the risk of neurological injury.

V-Y vertebral body osteotomy for the treatment of fixed sagittal plane spinal deformity

Background contextFixed sagittal plane imbalance (FSI) has traditionally been corrected by either opening or closing wedge osteotomies or vertebral column resections. These methods involve multiple vertebrae and have been associated with limited degrees of correction and/or neurovascular compromise. PurposeWe describe a new V-Y vertebral osteotomy (VYO) that involves a single vertebra, allowing for correction of all three columns in a safer fashion. Study designA prospective assessment of the degree of correction pre- and post-VYO in a tertiary spinal center. Patient sampleTen consecutive patients presenting with sagittal plane imbalance were enrolled in this study. Outcome measuresOutcomes were assessed with pre- (preop) and postoperative (postop) outcome questionnaires (Oswestry Disability Index [ODI] and Scoliosis Research Society-24) and radiography. MethodsTen patients underwent VYO at L3 with varying levels of instrumentation. The procedure involves a V-shaped osteotomy in the sagittal plane, sparing the anterior 50% of the body, the apex of which is then converted to a Y shape, and the osteotomy closed. ResultsPatients were followed for a mean of 36 months (24–48 months). The procedure led to significant improvements in sagittal balance, lumbar lordosis, thoracic kyphosis, coronal balance, sacral inclination, and pelvic incidence. The average degree of correction achieved was 44.58°±6.19° (mean±standard deviation). The mean blood loss was 1,287±350 mL and the operative time was 220±24 minutes. The mean preop ODI was 72% (range 58%–85%) and postop ODI averaged 22% (range 10%–30%). The mean preop SRS-24 score was 30.1 and postop was 101. ConclusionsThe VYO provides a safe correction of up to 45° at a single osteotomy site in FSI patients. It involves an isolated posterior approach and is recommended for corrections below the region of the conus.

Treatment of dystrophic scoliosis in neurofibromatosis Type 1 with one-stage posterior pedicle screw technique

Background contextCorrective surgery for dystrophic scoliosis in neurofibromatosis Type 1 (NF-1) is challenging. There are various surgical methods, all with unsatisfactory outcomes. PurposeThe purpose of the study was to evaluate the clinical outcomes of the treatment of dystrophic scoliosis in NF-1 with one-stage posterior pedicle screw approach. Study designThis is a retrospective clinical study. Patient sampleSixteen patients with dystrophic scoliosis in NF-1 underwent one-stage posterior surgery with pedicle screw system. Outcome measurementWe used preoperative and postoperative whole-spine radiographs to determine coronal and sagittal Cobb angles (curve correction); distance between apex vertebra and central sacral vertical line (DAC), pelvic obliquity, and shoulder tilt (coronal balance improvement); and sagittal vertical axis and pelvic tilt angle (sagittal balance improvement). We assessed the fusion rate using fusion segment computed tomography scan. MethodsPatients underwent surgery with or without osteotomy according to spinal flexibility. Fusion segment selection method of fusion segments selection which mean fusing from one or two levels proximal to upper end vertebra to one or two levels distal to the lower end vertebra (EV+1 or 2) or stable vertebrae fusion. There were no study-specific conflict of interest–associated biases. ResultsThe average follow-up time was 40.9 months. Mean scoliosis and kyphosis improved from 83.2° to 27.6° and 58.5° to 26.8°, respectively; at the last follow-up, it was 30.4° and 27.4°, respectively. Mean DAC, pelvic obliquity, and shoulder tilt improved from 53.0 to 23.9, 8.1 to 4.9, and 9.8 to 7.5 mm, respectively. Sagittal vertical axis and pelvic tilt angle improved from −5.8 to 1.6 mm and 17.9° to −5.8°, respectively. During follow-up, mean coronal and sagittal correction losses were 2.8° and 0.7°, respectively. Two EV+1 or 2 patients had decompensation. No pseudoarthrosis was identified. ConclusionsThe one-stage posterior pedicle screw approach is safe and effective in the treatment of dystrophic scoliosis in NF-1. Posterior vertebral column resection is recommended if flexibility is less than 35%. Stable vertebrae fusing is recommended.

Controversial issues in kyphoplasty and vertebroplasty in osteoporotic vertebral fractures.

Kyphoplasty (KP) and vertebroplasty (VP) have been successfully employed for many years for the treatment of osteoporotic vertebral fractures. The purpose of this review is to resolve the controversial issues raised by the two randomized trials that claimed no difference between VP and SHAM procedure. In particular we compare nonsurgical management (NSM) and KP and VP, in terms of clinical parameters (pain, disability, quality of life, and new fractures), cost-effectiveness, radiological variables (kyphosis correction and vertebral height restoration), and VP versus KP for cement extravasation and complications profile. Cement types and optimal filling are analyzed and technological innovations are presented. Finally unipedicular/bipedicular techniques are compared. Conclusion. VP and KP are superior to NSM in clinical and radiological parameters and probably more cost-effective. KP is superior to VP in sagittal balance improvement and cement leaking. Complications are rare but serious adverse events have been described, so caution should be exerted. Unilateral procedures should be pursued whenever feasible. Upcoming randomized trials (CEEP, OSTEO-6, STIC-2, and VERTOS IV) will provide the missing link.

Does Correction of Preoperative Coronal Imbalance Make a Difference in Outcomes of Adult Patients With Deformity?

Retrospective study with prospectively collected outcomes data. Determine the significance of coronal balance on spinal deformity surgery outcomes. Sagittal balance has been confirmed as an important radiographic parameter correlating with adult deformity treatment outcomes. The significance of coronal balance on functional outcomes is less clear. Eighty-five patients with more than 4 cm of coronal imbalance who underwent reconstructive spinal surgery were evaluated to determine the significance of coronal balance on functional outcomes as measured with the Oswestry Disability Index (ODI) and Scoliosis Research Society outcomes questionnaires. Sixty-two patients had combined coronal (>4 cm) and sagittal imbalance (>5 cm), while 23 patients had coronal imbalance alone. Postoperatively, 85% of patients demonstrated improved coronal balance. The mean improvement in the coronal C7 plumb line was 26 mm for a mean correction of 42%. The mean preoperative sagittal C7 plumb line in patients with combined coronal and sagittal imbalance was 118 mm (range, 50-310 mm) and improved to a mean 49 mm. The mean preoperative and postoperative ODI scores were 42 (range, 0-90) and 27 (range, 0-78), for a mean improvement of 15 (36%) (P = 0.00001; 95% CI, 12-20). The mean Scoliosis Research Society scores improved by 17 points (29%) (P = 0.00). Younger age (P = 0.008) and improvement in sagittal balance (P = 0.014) were positive predictors for improved ODI scores. Improvement in sagittal balance (P = 0.010) was a positive predictor for improved Scoliosis Research Society scores. In patients with combined coronal and sagittal imbalance, improvement in sagittal balance was the most significant predictor for improved ODI scores (P = 0.009). In patients with preoperative coronal imbalance alone, improvement in coronal balance trended toward, but was not a significant predictor for improved ODI (P = 0.092). Sagittal balance improvement is the strongest predictor of improved outcomes in patients with combined coronal and sagittal imbalance. In patients with coronal imbalance alone, improvement in coronal balance was not a factor for predicting improved functional outcomes.

Improvement of sagittal balance and lumbar lordosis following less invasive adult spinal deformity surgery with expandable cages and percutaneous instrumentation

The treatment of adult spinal deformity (ASD) remains a challenge for the spine surgeon. While minimally invasive surgery (MIS) has many favorable attributes that would be of great benefit for the ASD population, improvements in lordosis and sagittal balance have remained elusive in cases involving the MIS approach. This report describes the evolution of an MIS method for treating ASD with attention to sagittal correction. Over an 18-month period 25 patients with thoracolumbar scoliosis were treated surgically. The mean patient age was 72 years, and 68% of the population was female. Patients were treated with multilevel facet osteotomies and interbody fusion in which expandable cages (mean 3.2 levels) were placed and percutaneous screw fixation (mean 5.3 levels) was performed. Seven patients underwent supplemental percutaneous iliac fixation. All patients underwent MIS without conversion to a traditional open procedure. The mean operative time was 273 mins and the mean blood loss was 416 ml. There were no intraoperative complications. The Cobb angle over the scoliotic deformity improved from a mean of 29.2° to that of 9.0° (p < 0.001). Lumbar lordosis between L-1 and S-1 improved from a mean of 27.8° to one of 42.6° (p < 0.001). Sagittal vertical axis improved from 7.4 cm to 4.3 cm (p = 0.001). Numeric pain scale scores improved as well, an average of 3.3 and 4.2 for the leg and back, respectively. A mean improvement of 20.8 points on the Oswestry Disability Index was seen at 12 months. Complications included: two cases requiring hardware repositioning, one case of screw pullout, one asymptomatic pedicle screw breach, prolonged hospitalization from constipation, and one acute coronary syndrome developing 3 days after surgery without myocardial damage. An expanding body of evidence suggests that sagittal balance remains a keystone for good outcomes after ASD surgery. Minimally invasive surgery that involves a combination of osteotomies, interbody height restoration, and advanced fixation techniques may achieve this goal in patients with less severe deformities. While feasibility will have to be proven with larger series and improved surgical methods, the present technique holds promise as a means of reducing the significant morbidity associated with surgery in the ASD population.

Change in Sagittal Balance With Placement of an Interspinous Spacer

A prospective case series. To determine the effect of X-STOP implantation on sagittal spinal balance using 36-inch films. Interspinous process spacers have been shown as an effective treatment of neurogenic claudication. The devices block the last few degrees of extension at the stenotic level, thus preventing compression of the nerve roots. These devices have been criticized because they may push the patient's spine into a kyphotic position. However, opening the stenotic level may allow a patient to stand more upright, thereby improving sagittal balance. Institutional review board's approval was obtained. A prospective study of 20 patients who were undergoing an X-STOP insertion was utilized. Their spines were x-rayed preoperatively and postoperatively with 36-inch films. Preoperative and postoperative sagittal balance was measured with a C7 body plum line on both films and the difference was measured. Lumbar lordosis was also compared using Cobb angles. Measurements taken from lateral full-length spine radio-graphs showed an average improvement in sagittal balance of 2.0 cm (range -3.7 to 6.1 cm). The average change in lordosis was -1.1°. Although previous studies of interspinous process distraction have examined segmental lordosis, disc angles, and other parameters, this study is the first to examine overall spinal balance on full-length films. Interspinous distraction does not seem to be detrimental to sagittal balance, and may improve it.

Sagittal Cervical Alignment After Cervical Disc Arthroplasty and Anterior Cervical Discectomy and Fusion

Radiographic results of a multicenter, prospective randomized study comparing 1-level cervical total disc replacement (TDR-C) with anterior cervical discectomy and fusion (ACDF). To evaluate the effect on device-level lordosis, cranial and caudal adjacent level lordosis, and overall cervical sagittal alignment (C2-C6) after TDR-C or ACDF. Cervical total disc replacement (TDR-C) has emerged as a promising alternative to ACDF in a select group of patients. The maintenance and/or improvement of sagittal balance is essential in preserving functionality after reconstructive spinal procedures. Recent studies have documented changes in spinal alignment after TDR-C, however, no studies have compared these changes to those noted in matched group of patients that have undergone ACDF. Radiographic data were obtained from the randomized group of a multicenter, randomized, prospective, controlled study comparing TDR-C (ProDisc-C, Synthes Spine, West Chester, PA) with ACDF in the treatment of 1-level cervical disc disease. Complete radiographic data were available for 89 TDR-C patients (average age: 42.2 years) and 91 ACDF patients (average age: 41.7 years). Cervical lordosis at the device level, cranial and caudal adjacent levels, and total cervical lordosis (C2-C6) were independently measured before surgery and 2 years after surgery using custom image stabilization software (Quantitative Motion Analysis, Medical Metrics, Inc, Houston, TX). C5-C6 was the most common operative level (TDR-C: 54%; ACDF: 55%). At 2 years after surgery, the TDR-C group experienced statistically significant changes in lordosis of 3.0 degrees (P < 0.001), 0.90 degrees (P = 0.006), and -1.9 degrees (P < 0.001) at the operative, cranial, and caudal adj-acent levels, respectively. ACDF experienced changes in lordosis of 4.2 degrees (P < 0.001), 1.0 degrees (P = 0.001), and -1.5 degrees (P = 0.001), respectively. The between-group differences were significant at the operative level (P = 0.03) and the caudal adjacent level (P = 0.05). Total cervical lordosis increased in both TDR-C and ACDF by 3.1 degrees and 3.8 degrees , respectively (P = 0.49). In both TDR-C and ACDF, lordosis increased at the device-level, cranial adjacent level, and in total cervical lordosis, while lordosis decreased at the caudal adjacent level. Although ACDF facilitated a greater increase in device level lordosis (+1.25 degrees ) and less loss of lordosis at the caudal adjacent level compared with TDR-C (-0.39 degrees ), the clinical relevance of the small differences remain unknown.

Clinical and radiographic outcomes of thoracic and lumbar pedicle subtraction osteotomy for fixed sagittal imbalance

The authors conducted a study to evaluate the radiographically documented and functional outcomes obtained in patients who underwent pedicle subtraction osteotomy (PSO). They also compared outcomes after classification of cases into thoracic and lumbar PSO subgroups. The authors analyzed data obtained in 35 consecutive PSO-treated patients with sagittal imbalance. One surgeon performed all surgeries. The minimal follow-up period was 2 years. Events during the perioperative course and complications were noted. Standing long-film radiographs of the spine were obtained and measurements were made preoperatively, immediately postoperatively, and at most recent follow-up examination. The modified Prolo Scale and the 22-item Scoliosis Research Society (SRS-22) Outcomes Questionnaire were administered. Early complications after PSO included neurological injury, wound-related problems, and nosocomial infections. Late complications were limited to pseudarthrosis and attendant instrumentation failure. Early and late complication rates ranged from 10 to 30% for both thoracic and lumbar PSO cohorts. Lumbar PSO was associated with improvements in local, segmental, and global measures of sagittal balance, whereas thoracic PSO was only associated with local improvement. Most patients rated their functional status as fair to good according to the modified Prolo Scale and reported, according to the SRS-22 Outcomes Questionnaire, that they were satisfied with the overall treatment of their back condition. The ability to perform a PSO at both lumbar and thoracic levels is a powerful asset for the spine surgeon treating spinal deformity. In the present study radiographic and clinical outcomes were superior when PSO was used to treat lumbar deformity rather than thoracic deformity because of several anatomical and technical obstacles that hindered the thoracic procedure. Nevertheless, the thoracic PSO proved a useful addition with which to produce regional improvement in sagittal balance for patients with a fixed thoracic kyphosis.