Vertebral Wedging Research Articles

Risk factors for coronal oblique take-off following adult spinal deformity surgery using lateral lumbar interbody fusion and open posterior corrective fusion.

To evaluate risk factors associated with oblique take-off (OT) following lateral lumbar interbody fusion (LLIF) for adult spinal deformity. Thirty-nine consecutive patients (mean age 67.9years) with scoliosis of the lumbar curve (> 30°) were evaluated. Multilevel LLIF, followed by open thoraco-pelvic posterior corrective fusion after 1week, was performed. We defined OT as a distance of > 25mm between the C7 plumb line and the central sacral vertical line and examined risk factors by dividing the patients into the OT and non-OT groups. OT occurred in 11 patients (28%), all showing a tilt to the convex side. The correction rate of the lumbar curve was approximately 70% range for both groups, which indicated good correction. Preoperative radiographs showed a high L1-central sacral vertical line in the standing position; high L5 tilt in the supine position; high L3, L4, and L5 tilts to the convex side in the supine-bending position; and a high L4 vertebral wedge on the convex side in OT cases. Multiple logistic regression analysis showed that an L4 tilt to the concave side in the bending position was the most effective predictor of OT (odds ratio = 1.104, P = 0.047). For a cutoff value of 16°, the sensitivity and specificity were 73% and 61%, respectively, according to the receiver operating characteristic curve analysis (area under the curve = 0.73). OT occurred in 28% of adult scoliosis patients following LLIF. An L4 tilt > 16° to the concave side in the bending position was the most valuable risk factor. IV.

Short Segment Pedicle Screw Fixation for Thoracolumbar Burst Fractures. Percutaneous without Fusion Versus Open Pedicle Screw Fixation with Posterolateral Fusion

Background: Fixation of thoracolumbar burst fractures (TLBF) with short segment pedicle screw construct has become popular over last few decades. Spine surgeons have started to deal advanced degenerative spinal pathologies with percutaneous pedicle screw fixation (PPSF) as well. Short segment PPSF has been demonstrated to be an effective treatment option for TLBF fixation in fewer studies so far. This study compared the short segment open pedicle screw fixation (OPSF) with fusion to a short segment PPSF without fusion in the management of TLBF. Methods: Between December 2019 and October 2021, fifty nine patients underwent short-segment pedicle screw fixation, 32 PPSF while 27 OPSF for TLBF. Each of the three follow-up examinations included radiographs to ensure that the spinal column had recovered to its pre-injury state. A lateral thoracolumbar radiograph was used to calculate the Cobb angle, vertebral wedge angle, and vertebral body compression ratio. In this study, patients' pain and function were assessed using the VAS, the Frankel grading system, and the Low Back Outcome Score (LBOS). Additionally, the volume of blood loss and the time required to finish the procedure were also noted. Results: Regional Cobb angle improved post operatively in both groups without any disparity when assessed the two groups, which was noticed till three months. Operative time and blood loss was less in PPSF. LBOS and VAS markedly improved during early follow ups in PPSF group compare to OPSF. Concluding follow up did not show significant difference between PPSF and OPSF. Conclusions: Open or percutaneous short-segment pedicle fixation with or without fusion is secure and efficient treatment option for TLBF. PPSF alone resulted in a greater reduction in pain and improvement in functional ability than the OPSF during initial time period which substantially improve overall outcome in management of TLBF.

Paraspinal myopathy-induced intervertebral disc degeneration and thoracolumbar kyphosis in TSC1mKO mice model—a preliminary study

BACKGROUNDIncreasing kyphosis of the spine in a human is a well-recognized clinical phenomenon that has been associated with back pain, poor physical performance and disability. The pathophysiology of age-related kyphosis is complex and has been associated with physiological changes in vertebrae, intervertebral disc (IVD) and paraspinal musculature, which current cross-sectional studies are unable to demonstrate. Creating an in vivo, paraspinal myopathic animal model for longitudinal study of these changes under controlled conditions is thus warranted. PURPOSETo confirm the TSC1 gene knockout effect on paraspinal muscle musculature; to analyze the development of spinal kyphosis, IVD degeneration and vertebra structural changes in a longitudinal manner to gain insights into the relationship between these processes. STUDY DESIGNA prospective cohort study of 28 female mice, divided into 4 groups—9-month-old TSC1mKO (n=7), 9-month-old control (n=4), 12-month-old TSC1mKO (n=8), and 12-month-old controls (n=9). METHODSHigh resolution micro-computed tomography was used to measure sagittal spinal alignment (Cobb's angle), vertebral height, vertebral body wedging, disc height index (DHI), disc wedge index (DWI), histomorphometry of trabecular bone and erector spinae muscle cross-sectional area. Paraspinal muscle specimens were harvested to assess for myopathic features with H&E stain, muscle fiber size, density of triangular fiber and central nucleus with WGA/DAPI stain, and percentage of fibers with PGC-1α stain. Intervertebral discs were evaluated for disc score using FAST stain. RESULTSCompared to controls, paraspinal muscle sections revealed features of myopathy in TSC1mKO mice similar to human sarcopenic paraspinal muscle. While there was significantly greater presence of small triangular fiber and density of central nucleus in 9-and 12-month-old TSC1mKO mice, significantly larger muscle fibers and decreased erector spinae muscle cross-sectional area were only found in 12-month-old TSC1mKO mice compared to controls. TSC1mKO mice developed accelerated thoracolumbar kyphosis, with significantly larger Cobb angles found only at 12 months old. Structural changes to the trabecular bone in terms of higher bone volume fraction and quality, as well as vertebral body wedging were observed only in 12-month-old TSC1mKO mice when compared to controls. Disc degeneration was observed as early as 9 months in TSC1mKO mice and corresponded with disc wedging. However, significant disc height loss was only observed when comparing 12-month-old TSC1mKO mice with controls. CONCLUSIONSThis study successfully shows the TSC1 gene knockout effect on the development of paraspinal muscle myopathy in a mouse which is characteristic of sarcopenia. The TSC1mKO mice is by far the best model available to study the pathological consequence of sarcopenia on mice spine. With paraspinal muscle myopathy established as early as 9 months, TSC1mKO mice developed disc degeneration and disc wedging. This is followed by kyphosis of the spine at 12 months with concomitant disc height loss and vertebral body wedging due to bone remodeling. Age-related bone loss was not found in our study, suggesting osteoporosis and myopathy-induced vertebral body wedging are likely two independent processes. CLINICAL SIGNIFICANCEThis is the first study to provide key insights on the early and late consequences of paraspinal myopathy on intervertebral disc degeneration, spinal kyphosis, and vertebral body changes. With this new understanding, future studies evaluating therapies for spinal degeneration may be performed to develop time-sensitive interventions.

Contribution of postoperative vertebral remodeling to reversal of vertebral wedging and prevention of correction loss in patients with adolescent Scheuermann's kyphosis.

This study aimed to investigate reversal of vertebral wedging and to evaluate the contribution of vertebral remodeling to correction maintenance in patients with adolescent Scheuermann's kyphosis (SK) after posterior-only instrumented correction. A retrospective cohort study of patients with SK was performed. In total, 45 SK patients aged 10-20 years at surgery were included. All patients received at least 24 months of follow-up and had Risser sign greater than grade 4 at latest follow-up. Patients with Risser grade 3 or less at surgery were assigned to the low-Risser group, whereas those with Risser grade 4 or 5 were assigned to the high-Risser group. Radiographic data and patient-reported outcomes were collected preoperatively, immediately postoperatively, and at latest follow-up and compared between the two groups. Remarkable postoperative correction of global kyphosis was observed, with similar correction rates between the two groups (p = 0.380). However, correction loss was slightly but significantly less in the low-Risser group during follow-up (p < 0.001). The ratio between anterior vertebral body height (AVBH) and posterior vertebral body height (PVBH) of deformed vertebrae notably increased in SK patients from postoperation to latest follow-up (p < 0.05). Loss of correction of global kyphosis was significantly and negatively correlated with increased AVBH/PVBH ratio. Compared with the high-Risser group, the low-Risser group had significantly greater increase in AVBH/PVBH ratio during follow-up (p < 0.05). The two groups had similar preoperative and postoperative Scoliosis Research Society-22 questionnaire scores for all domains. Obvious reversal in wedge deformation of vertebrae was observed in adolescent SK patients. Patients with substantial growth potential had greater vertebral remodeling and less correction loss. Structural remodeling of vertebral bodies has a positive effect and protects against correction loss. These results could be help guide treatment decision-making.

Vertebral Body Bruise Resulting in Vertebral Wedging

The patient was a 77-year-old man whose head and back impacted the ground after falling from a stepladder. On arrival, plain roentgenography and whole body computed tomography failed to depict a responsible spinal lesion. As he could walk, his wound was sutured and he was discharged to home. However, on the following day, he was unable to stand due to severe back pain. Urgent magnetic resonance image (MRI) revealed a high-intensity signal in the 12th thoracic vertebral body without compressive deformity. Follow-up roentgenography at 10 days showed compressive change at the 12th thoracic vertebral body; thus, a corset was applied at the thoracolumbar position. Final lumbar roentgenography at 6 months revealed compression of the thoracic vertebral body. In the present case an elderly patient, who initially showed a bone bruise, showed delayed compressive changes in the thoracic vertebral body. In our super-aging society, further studies are required to investigate the natural history of vertebral body bruises in elderly individuals.

Equivalent values between anterior vertebral height, wedge ratio, and wedge angle in osteoporotic vertebral fractures.

Vertebral mobility (V-mobility) has been used to diagnose fresh osteoporotic vertebral fractures (OVFs), and determine or predict bone union by setting cutoff values for these purposes. V-mobility is defined as the difference in shape of vertebral bodies between lateral radiographs taken in weight-bearing and non-weight-bearing positions. The parameters for V-mobility have varied in previous reports among anterior vertebral height (Ha, mm), wedge ratio (WR, %), and wedge angle (WA, degrees). The present study aimed to clarify WR and WA equivalent to Ha of 1.0mm, and to compare the reported cutoff values for V-mobility presented as Ha, WR, or WA. Lateral radiographs of 446 normal vertebrae (grade 0) and 146 deformed vertebrae (grade 1-3) from T11 to L2 were obtained from 183 female patients aged > 60years. WR (%) values equivalent to Ha of 1.0mm were calculated by Ha (1.0mm)/Hp × 100 (Hp: posterior vertebral height). Corresponding WA values were calculated by trigonometric function using vertebral dimensions. The mean WR values equivalent to Ha of 1.0mm in the vertebrae from T11 to L2 were 3.2%, 3.2%, 3.5%, and 3.7% for grades 0, 1, 2, and 3, respectively, and the corresponding WA values were 1.6°, 1.6°, 1.5°, and 1.4°. The equivalent values for V-mobility presented as Ha, WR, and WA were obtained. The mean WR and WA values equivalent to Ha of 1.0mm in grade 1-3 vertebrae were 3.5% and 1.5°, respectively.

33. Biomechanical analysis of the novel active apex correction technique using a patient specific finite element approach with 6-month follow-up

<h3>BACKGROUND CONTEXT</h3> Traditionally, SHILLA and growing rods have been the 2 mainstays for surgical treatment of early onset scoliosis (EOS) patients. Multiple studies have previously highlighted the shortcomings of both techniques; the SHILLA suffer a loss of correction or reappearance of deformity through crank-shafting or adding-on (eg, distal migration) and growing rods require multiple reoperation with additional complications. Newer techniques like the active apex correction (APC) provide an excellent surgical alternate; designed to reduce the prevalence of above complication by avoiding apical fusion amongst other benefits. The current study builds on earlier clinical studies on the APC technique, exploring the clinical of the technique using a finite element (FE) approach. <h3>PURPOSE</h3> The objective is to simulate and explore the effect of apical remodulation using the APC technique over a 6-month follow-up period for 2 patient-specific FE models. <h3>STUDY DESIGN/SETTING</h3> A patient-specific, FE study simulating APC with 6-months follow-up. <h3>METHODS</h3> Two representative scoliotic models were developed to match patient AP and lateral radiographs provided by the surgeon. To simulate the APC technique; the apex was pushed medially followed by compression of the convex side of apex (using 2 screws implanted proximal and distal to the most wedged vertebrae). The rest of construct was then completed to simulate the APC (patient 1 had a dual compression done at primary and secondary curves). The model then simulated the effect of gravity and muscle forces, followed by epiphyseal spinal growth based on the Hueter-Volkmann principle. Relevant clinical output parameters such as primary cobb, AVT, vertebral wedging etc. were recorded for these two models and compared with the clinical data (as available). To ensure clinical relevance, at each step the model inputs and process were checked by a surgeon who regularly performs APC. <h3>RESULTS</h3> Both patient 1 and 2 showed a significant reduction in the Cobb angle (24° and 15°, respectively) for the primary curve following the APC surgery. The AVT was significantly reduced with the surgical correction (∼ 50% in both cases). Additionally, the vertebral wedging in the apical region was significantly reduced due to the APC technique for both patients. Kyphotic angles (T4-T12) were also reduced by 50 % and 40% for patient 1 &2 respectively. Furthermore, at the gravity loading and 6-month spinal growth time points, the output parameters showed a consistent maintenance of the correction achieved by the APC technique (reduction in the Cobb angle, vertebral wedging and translation) for both patients. <h3>CONCLUSIONS</h3> The output parameters from the FE models suggest excellent clinical outcomes; maintenance of coronal correction, reduction in AVT and apical vertebral wedging. While this study is limited in terms of follow-up time as well as sample size, it paves the way for additional research expanding the preliminary results to get a broader biomechanical understanding of the APC. At the same time, the results showcase the enormous potential of this novel technique as a legitimate alternative to incumbent techniques, that can be employed by spine surgeons across the world in an easy, effective and cost-effective manner. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Sagittal wedging of intervertebral discs and vertebral bodies in the cervical spine and their associations with age, sex and cervical lordosis: A large-scale morphological study.

Many recent studies have focused on the functional and clinical importance of cervical lordosis. However, there is little accurate knowledge of the anatomical parameters that constitute cervical lordosis (i.e., the sagittal wedging angles of intervertebral discs and vertebral bodies) and their associations with age and sex. Standing lateral cervical radiographs of 1020 subjects (424 males, 596 females) with a mean age of 36.6 ± 17.0 years (range 7-95 years) were evaluated retrospectively. Cervical lordosis, the sum of intervertebral disc wedging angles from C2/C3 to C6/C7 and the sum of vertebral body wedging angles from C3 to C7 were measured. The sum of intervertebral disc wedging and the sum of vertebral body wedging were 20.6° ± 14.7° and -12.8° ± 10.3°, respectively. The sum of intervertebral disc wedging increased significantly with age and was significantly greater in males than females, whereas there was no sex-related difference in the sum of vertebral body wedging. The sum of intervertebral disc wedging was negatively correlated with sum of vertebral body wedging. Wedging of discs contributed to C2-C7 cervical lordosis more significantly than wedging of vertebral bodies. There were moderate positive correlations between cervical lordosis and intervertebral disc wedging angles at C3/C4, C4/C5 and C5/C6; weak correlations were observed at C2/C3 and C6/C7. This study constitutes the largest currently available analysis comprehensively documenting the anatomical characteristics of sagittal wedging of intervertebral discs and vertebral bodies in the cervical spine. The findings could improve understanding of the internal architecture of cervical lordosis among clinicians.

Imageology study of correlation loss and its related factors after short-segment pedicle screw reduction and fixation for lumbar fractures

To analyze the correction loss after posterior segmental fixation for lumbar spine fractures and explore the related image factors. Posterior short-segment fixation was received in 48 patients with L2-L4 fractures. There were 32 males and 16 females, with ages of 23 to 60 (45.98±8.20) yeaes. The anterior vertebrae height (AVH), vertebral wedge angle (VWA) of the injured vertebra and local kyphosis angle (LKA) were measured before operation, 1 week after operation and the final follow-up. The loss of segmental discal angle (LoSDA), LKA(LoLKA), AVH(LoAVH) were calculated between 1 week postoperative and the last follow up. Preoperative load-sharing scores(LSS), TLICS scores, and adjacent intervertebral disc injuries (IDIs) were assessed. Then the correlation between the age, follow up time, LSS, TLICS, IDIs and the correction loss was analyzed. The average follow-up was 12 to 18 (16.13±5.39) months. LKA, AVH and VWA at 1 week postoperative and those at the final follow up, were significantly improved compared with those preoperative (P<0.05). In the final follow up, the average LKA(5.70±3.17)° and AVH(4.31±5.95)% correction loss were observed compared with those 1 week postoperative(P<0.05). Otherwise the lose of VWA was not obvious(P>0.05). Univariate analysis showed that the SDA (r=0.706, 0.579, 0.449) and LKA(r=0.715, 0.566, 0.502) correction loss were aggravated with the increase of LSS, TLICS and IDIs, and AVH (r=-0.325, -0.219) correction loss was aggravated with the increase of LSS and TLICS(P<0.05). Multivariate analysis showed that increased LSS scores were all risk factors for segmental disc angle (SDA) loss, LKA correction loss, and AVH correction loss (P<0.05). The angle of adjacent intervertebral discs and anterior height of injured vertebrae were lost statistically after posterior short-segment pedicle screw treatment for lumbar fractures, and multivariate analysis showed that all of them were correlated with load-sharing score.

Feasibility of Single-Stage Posterior Passive Correction and Fusion Surgery for Congenital Scoliosis in Adolescent Patients Who Have Attained Skeletal Maturity.

Study DesignRetrospective study.PurposeTo report the perioperative and radiological outcomes of single-stage posterior passive correction and fusion (SSPPCF) in adolescent patients who present with congenital scoliosis.Overview of LiteratureThe surgical treatment for congenital scoliosis is complex. There is no definitive guide on surgical options for skeletally matured adolescent patients who have congenital scoliosis.MethodsPatients with congenital scoliosis who underwent SSPPCF using a pedicle screw system were reviewed. We identified the following three surgical indications: (1) hemivertebra or wedge vertebra over the thoracic or thoracolumbar region with structural lumbar curves, (2) hemivertebra or wedge vertebra at the lumbar region with significant pelvic obliquity or sacral slanting, and (3) mixed or complex congenital scoliosis. The demographic, perioperative, and radiographic data of these patients were collected.ResultsThirty-four patients were reviewed. The mean patient age was 14.6±3.4 years. There were 13 hemivertebrae, three wedged vertebrae, two butterfly vertebrae, three hemivertebrae with butterfly vertebra, eight unsegmented bars, and five multiple complex lesions. The average surgical duration was 219.4±68.8 minutes. The average blood loss was 1,208.4±763.5 mL. Seven patients required allogeneic blood transfusion. The mean hospital stay duration was 6.1±2.5 days. The complication rate was 11.8% (4/34): one patient had severe blood loss, one had rod breakage, and two had distal adding-on. The Cobb angle reduced from 65.9°±17.4° to 36.3°±15.3° (p<0.001) with a correction rate (CR) of 44.8%±17.4%. The regional kyphotic angle decreased from 39.9°±20.5° to 27.5°±13.9° (p=0.001) with a CR of 19.3%±49.6%. Radiographic parameters (radiographic shoulder height, clavicle angle, T1 tilt, cervical axis, pelvic obliquity, coronal balance, and apical vertebral translation) showed significant improvement postoperatively.ConclusionsSSPPCF was a feasible option for adolescent patients with congenital scoliosis who were skeletally matured.

Safety and Efficacy of Balloon Kyphoplasty for Vertebral Fractures With Posterior Wall Disruption.

Percutaneous balloon kyphoplasty (BK) is widely accepted as both a safe and effective method for the treatment of symptomatic benign vertebral compression fractures (VCFs) of the thoracic and lumbar spines. A disruption in the posterior wall of the affected vertebra is often considered to be a relative or an absolute contraindication to BK. This study was performed to determine the safety as well as the efficacy of BK for vertebral body compression fractures associated with posterior wall disruption. This was a retrospective, nonrandomized clinical cohort investigation of patients with VCF and posterior wall disruption treated with BK between 2010 and 2018. All cases were performed using a bipedicular technique. Each case was examined for cement leakage, anterior vertebral body height restoration, improvement in pain (determined by VAS) from baseline and 6-week postprocedure, and clinical sequelae from cement leakage. Ninety-eight consecutive patients with 157 VCF levels who underwent BK were evaluated. There was a significant improvement in anterior vertebral height, vertebral wedge angle, and local kyphotic angle in all cases. The mean preoperative VAS improved from 8.7 preprocedure to 2.5 postprocedure (P = .001). There were 14 (9%) cases with asymptomatic cement leakage outside of the vertebral body, and no patients experienced postprocedure neurological symptoms at the 6-week follow up. BK in the setting of posterior wall disruption was found to be a safe and highly effective treatment for patients with benign compression fractures. Posterior wall disruption should not be considered an absolute contraindication to BK.

Does spinal sagittal imbalance lead to future vertebral compression fractures in osteoporosis patients?

Background contextMany risk factors for osteoporotic vertebral compression fractures (OVCFs) have been reported. However, there are few reports on the relationship between spine sagittal parameters in patients with osteoporosis. PurposeTo explore whether: spinal sagittal imbalance is associated with future vertebral compression fractures in osteoporosis patients; spinal sagittal parameters in patients with osteoporosis can predict the occurrence of vertebral compression fractures. Study designA retrospective cohort study. Patient samplePatients with osteoporosis. Outcome measuresOccurrence of OVCFs during the follow-up period. MethodsFrom January 2017 to October 2019, eligible patients with osteoporosis at the initial visit were enrolled. They were followed up to November 1, 2020. Based on whether OVCFs occurred during the follow-up, the patients were divided into two groups: the experimental group (vertebral compression fracture group) and the control group (no vertebral compression fracture group). Intragroup analysis was performed as follows: Pearson and Spearman correlation coefficients were used to calculate the correlation between each parameter. Intergroup analysis was performed as follows. For categorical variables, the chi-square test was used; for normally distributed continuous variables, an independent sample t-test was used; and for non-normally distributed variables, a two-sample nonparametric test was used. Binary logistic regression analysis and receiver operating characteristic (ROC) curves were used to determine independent risk factors and critical values, respectively. ResultsA total of 340 patients with osteoporosis were enrolled. The longest and shortest follow-up periods were 44 months and 12 months, respectively, with an average of 25.2±10.2 months. There were significant differences in age, bone mineral density (femur and lumbar), smoking history, medication treatment regularity, Thoracolumbar Kyphosis (TLK), Pelvic Tilt (PT), C7-S1 Sagittal Vertical Axis (C7-S1 SVA), and C2-7 Sagittal Vertical Axis (C2-7 SVA) between the experimental and control groups. There were no significant differences in sex, body mass index (BMI), alcohol consumption history, hypertension, diabetes, coronary heart disease, family history of osteoporosis, physical activity, Thoracic Kyphosis (TK), Lumbar Lordosis (LL), Pelvic Incidence (PI), Sacral Slope (SS), C2-C7 Cobb Angle (CL), T1 slope (T1S) or blood parameters. Through binary logistic regression analysis, we found that BMD, medication treatment regularity and C7-S1 SVA were independent risk factors for future vertebral compression fractures. According to the ROC curve, the prediction accuracy of C7-S1 SVA was the highest. Through the calculation of critical values, we found that when C7-S1 SVA was more than 3.81 cm, future OVCFs were more likely to occur, and for every 1cm increase in C7-S1 SVA, the incidence of future OVCFs would increase by 0.324 times (p<.001, OR=1.324). Through intragroup analysis, we further found that C7-S1 SVA was positively correlated with the percentage of vertebral body wedging. ConclusionsFor patients with osteoporosis, a C7-S1 SVA more than 3.81cm is significantly associated with a greater risk for vertebral compression fractures in the future.

RETRACTED ARTICLE: Percutaneous pedicle screw fixation combined with selective transforaminal endoscopic decompression for the treatment of thoracolumbar burst fracture

BackgroundThe objective of this study was to evaluate the feasibility, safety, efficacy, and indications of percutaneous pedicle screw fixation (PPSF) combined with selective transforaminal endoscopic decompression (TED) in the treatment of thoracolumbar burst fracture (TBLF).MethodsFrom August 2015 to October 2018, a total of 41 patients with single-segment TLBF (28 men and 13 women) were enrolled in this study. X-ray and computed tomography were obtained before surgery, 1 week after surgery, and 1 year after surgery to evaluate spinal recovery. In addition, we used the visual analog scale (VAS), the Oswestry Disability Index (ODI), the Japanese Orthopedic Association score (JOA), and the Frankel classification of neurological deficits to evaluate the effectiveness of the treatments.ResultsThe average follow-up time was 22.02 ± 8.28 months. The postoperative Cobb angle, vertebral body compression ratio, vertebral wedge angle, mid-sagittal canal diameter compression ratio, and Frankel grade were significantly improved. There were also significant improvements in the VAS (7.61 ± 1.41 vs. 1.17 ± 0.80, P < 0.001), ODI (89.82 ± 7.44 vs. 15.71 ± 13.50, P < 0.001), and JOA (6.90 ± 2.91 vs. 24.90 ± 3.03, P < 0.001).ConclusionsOur results showed that PPSF combined with selective TED in the treatment of TLBF had excellent efficacy, high safety, less secondary injury than other treatments, and a wide range of indications and that it could accurately distinguish patients who did not need spinal canal decompression after posterior fixation. PPSF combined with selective TED is therefore a good choice for the treatment of TLBF.

Risk factors of recurrent kyphosis in thoracolumbar burst fracture patients treated by short segmental pedicle screw fixation

OBJECTIVE To analyze the risk factors of recurrent kyphosis after removal of short segmental pedicle screw fixation in patients with thoracolumbar burst fractures. METHODS Retrospective analysis was conducted of 144 cases of thoracolumbar burst fractures without neurological impairment treated in Peking University Third Hospital from January 2010 to December 2017. There were 74 males and 70 females, with an average age of (39.1±13.2) years. The distribution of the injured vertebrae was T12: 42, L1: 72 and L2: 30, with fracture types of A3: 90, B1: 25 and B2: 29. The patients were divided into two groups: Recurrent kyphosis group (n=92) and non-recurrent kyphosis group (n=52). SPSS 26.0 software was used for univariate analysis and Logistic regression analysis. RESULTS The average follow-up time was 28 (20-113) months. The imaging indexes of pre-operation, 3 days post-operation, 12 months post-operation and the last follow-up were measured and compared. Anterior vertebral body height, segmental kyphosis, vertebral wadge angle and Gardner deformity were significantly improved after operation (P < 0.05), and there were some degrees of loss in the 1-year follow-up; anterior vertebral body height and vertebral wadge angle were no longer changed after the removal of the screws; however, segmental kyphosis and Gardner deformity were still aggravated after the removal of the screws (P < 0.05). There were some degrees of collapse of the height of the upper and lower discs during the follow-up. Univariate analysis showed that there were statistically significant differences (P < 0.05) between the two groups in gender, age (36.9 years vs. 43.0 years), upper disc injury, CT value (174 vs. 160), segmental kyphosis (16.6° vs. 13.3°), vertebral wadge angle (16.7° vs. 13.6°), Gardner deformity (19.1° vs. 15.2°) and ratio of anterior vertebral body height (0.65 vs. 0.71). Logistic regression analysis showed that male (OR: 2.88, 95%CI: 1.196-6.933), upper disc injury (OR: 2.962, 95%CI: 1.062-8.258) and injured vertebral wedge angle were risk factors of recurrent kyphosis after removal of internal fixation for thoracolumbar burst fracture (P < 0.05). CONCLUSION The patients with thoracolumbar burst fracture can obtain satisfactory effect immediately after posterior short segmental pedicle screw fixation, however, there may be some degree of loss during the follow-up. Male, upper disc injury and injured vertebral wedge angle are the risk factors of recurrent kyphosis after removal of internal fixation for thoracolumbar burst fracture.

Reduce the fractured central endplate in thoracolumbar fractures using percutaneous pedicle screws and instrumentational maneuvers: Technical strategy and radiological outcomes.

Traumatic thoracolumbar burst fracture is a common condition without a clear consensus on the best treatment approach. Percutaneous pedicle screw fixation (PPSF) techniques are widely used in practice, while its ability to correct fracture deformity is relatively weak, especially for the central area of the endplate. In this study, we reported a novel technique to reduce the fractured central endplate in thoracolumbar burst fractures. The new reduction technique uses six percutaneous pedicle screws for the fractured vertebra and its adjacent vertebrae. Pedicle screws implanted in the two adjacent vertebrae were parallel to the superior vertebral endplate, as routinely required. Two monoaxial pedicle screws implanted in the fractured vertebra were placed toward the anteroinferior portion of the fractured vertebral body. After routine instrumentation and ligamentotaxis reduction, the bolt heads of the four screws implanted in the adjacent vertebrae were first tightened, and then the bolt heads of the screws implanted in the fractured vertebra were gradually tighten to elevate the collapsed endplate. A fundamental principle of this technique is to implant the pedicle screw in the fractured vertebra towards the anteroinferior portion of the vertebra in such a way that the angle between the pedicle screw and the rod is oblique on lateral fluoroscopy. As such, when the bolt heads were tightened, the pedicle screws can be swung up to reduce the endplate fragments. The novel technique was performed in 24 patients with neurologically intact thoracolumbar AO type A3 fractures. The middle vertebral height ratio was significantly improved from 69.7%±7.6% after routine reduction to 85.1%±4.5% postoperatively (p<0.01). No complication was noticed for this new reduction technique. At 6-month follow-up, no significant correction loss of the middle and posterior vertebral height ratios, Cobb angle, and vertebral wedge angle was observed, while 5.8% of correction loss was observed for the anterior vertebral height ratio. The described reduction technique is simple, safe, and effective in reducing the collapsed central endplate in thoracolumbar burst fractures. Such a practical reduction strategy does not need additional medical costs.

Thoracic vertebral morphology in normal and scoliosis deformity in skeletally immature rabbits: A Longitudinal study.

ObjectiveTo measure age‐related changes in thoracic vertebral body heights (VBH) in skeletally immature normative and scoliotic rabbits to assess how VBH change during growth. To examine the potential link between the moment‐arm of the rib tether and vertebral wedging as well as the sum of the curvature angles at the apical level (T7). To assess the correlation between the magnitude of initial spine curve and final spine curve in the scoliotic group.MethodsEight healthy, skeletally immature normative New Zealand rabbits and ten skeletally immature scoliotic rabbits which underwent unilateral rib tethering were included retrospectively. Each rabbit was scanned at two to four time points (at 7, 11, 14 and 28 weeks). Three dimensional bone models of thoracic vertebrae (T1‐T12) were digitally segmented and reconstructed. VBH were calculated using surface landmark points from each thoracic vertebra. Apical level (T7) ± 2 levels in scoliotic rabbits were compared to their corresponding levels and time points in the normative group. The moment‐arms between the centroids of 2D projections of T3‐T9 vertebral bodies and the line which connects the centroids of the end levels were calculated.ResultsBilateral left‐right (L‐R) symmetry and anterior‐posterior (A‐P) asymmetry were observed in normative VBH. Bilateral concave‐convex (CC‐CX) asymmetry and (A‐P) asymmetry were observed in scoliotic VBH. No significant differences in growth rates were found between the normative and scoliotic groups. Vertebral wedging as well as curvature magnitude were positively correlated with the moment‐arms.ConclusionUnilateral rib tether applies compressive forces on both concave and convex sides, whereas compressive forces are lower on the latter. Knowing the amount of vertebral wedging or curve magnitude would enable us to predict the applied force (moment‐arms), which is important for planning a corrective surgery.

Comparing Muscle Activity and Spine Shape in Various Sitting Styles

Lower back pain is experienced by approximately 70% of the world's population, contributing to the worldwide burden of disease. Americans experience lower back pain at an estimated economic cost of $560–$635 billion. One contributing factor for back pain is posture, and more particularly, lack of awareness of dysfunctional posture. For example, many people sit in a slouched or forward-bent position, exacerbated by poor ergonomics while sitting or extended use of handheld digital devices while standing, such as looking down at a smartphone for long periods of time. This report describes a stacksitting technique that is one of the components of the Gokhale Method® for healthy, relaxed sitting and increased awareness of posture. The stacksitting process is illustrated with a case study, where the shape of the spine and the muscle activity are analyzed in parallel during three sitting styles: slouching, arched, and stacksitting. The spine curvature was characterized by the Gokhale SpineTracker™ wearable, which consists of five sensor units attached along the subjects' spines that are used to plot the spinal curve on a digital device such as a smartphone, tablet, or computer. Surface electromyographic (SEMG) recordings were made from the right upper trapezius, left upper trapezius, right midback, and left midback with a second device (Myoscan Pro sensors recorded with Biograph Procomp Infinity) while participants were seated in three postures: a slouched (forward-bent) position, an upright arched position, and an upright stacksitting position as trained by a Gokhale Method teacher. The case observations showed no significant difference in trapezius SEMG activity during each of the three positions. There was a slight increase in SEMG activity of the midback during stacksitting (1.1 μV) as compared with when slouched (0.64 μV), and a significant increase in SEMG activity when sitting arched (4.9 μV). As expected, the spinal activity tracking device showed significant straightening of the lower spine during the stacksitting position as compared with the slouched and arched positions. The observations suggest that the stacksitting position can be taught to others in a way that allows the vertebrae to be parallel to each other with very low levels of corresponding muscle activity. In contrast, sitting in an arched or slouched position could increase asymmetrical pressure on the disks, contributing to vertebral wedging, which could also contribute to spinal disk bulging and eventual back injury. The observations suggest that proper coaching may foster a stacksitting position of the spine, which could foster a healthier posture than slouched or arched spinal positions.

Vertebral growth modulation by posterior dynamic deformity correction device in skeletally immature patients with moderate adolescent idiopathic scoliosis

Study designRetrospective, comparative, multicenter.IntroductionGrowth modulating spinal implants are used in the management of scoliosis such as anterior vertebral body tethering. A motion-sparing posterior device (PDDC) was recently approved for the treatment of moderate AIS. The purpose of this study was to determine if the PDDC can modulate growth in skeletally immature patients with AIS.MethodsFrom a database of patients treated with the PDDC over 4 years, we identified those who had a minimum of 2 years follow-up. Pre-operative and post-operative Cobb angles and coronal plane wedging of the apical vertebra were evaluated on standing full length radiographs. Independent sample t test and one-way ANOVA with post-hoc Tukey HSD analysis was used to compare three groups in varying skeletal maturity: Risser 0–1, Risser 2–3, and Risser 4–5.Results45 patients (14.2-years old, 11–17) were evaluated with a mean pre-op curve of 46° (35°-66°). The average preoperative major curve magnitude, of either Lenke 1 or 5 curve type, was similar among the three groups 47.6°, 46° and 41.5°. Deformity correction was similar in the three groups, with reduction to 26.4°, 20.4° and 26.2°, respectively, at final follow-up [p < 0.05]. Pre-op wedging 7.4° (3.8°–15°) was reduced after surgery to 5.7° (1°–15°) (p < 0.05). Of those patients, Risser 0–1 (n = 16) had preoperative wedging of 9.5° (6°–14.5°) that was reduced to 5.4° (1°–8°) postoperatively (p < 0.05); Risser 2–3 (n = 15) had pre-op 7.7° (4°–15°) vs. post-op 7.0° (3°–15°); Risser 4–5 (n = 14) had pre-op 4.8° (3.8°–6.5°) vs. post-op 4.7° (3.7°–6.5°). Delta Wedging in Risser 0–1 stage was significantly different than for Risser 2–3 and for Risser 4–5.ConclusionThe posterior dynamic deformity correction device was able to modulate vertebral body wedging in skeletally immature patients with AIS. This was most evident in patients who were Risser 0–1. In contrast, curve correction was similar among the three groups. This finding lends support to the device’s ability to modulate growth.

Accuracy on the preoperative assessment of patients with adolescent idiopathic scoliosis using biplanar low-dose stereoradiography: a comparison with computed tomography

BackgroundAlthough computed tomography (CT) is commonly used to diagnose the scoliotic spine in patients with adolescent idiopathic scoliosis (AIS) preoperatively, it is limited by the high radiation and prone scanning position. Recently, a new biplanar stereoradiography (EOS) was used to image the scoliotic spine in an upright posture with significantly less radiation in non-severe AIS subjects. However, its reliability to assess preoperative AIS patients remains unreported. Hence, the purpose of this study is to compare the scoliotic curvature between prone (CT) and upright positions (EOS) in preoperative AIS patients.MethodsThirty-three pre-operative AIS patients (mean age:18.4 ± 4.2) were recruited. EOS was used to scan the whole thoracic spine at upright position. Whereas on the same day, a conventional CT scan was used to evaluate the spine in prone position. The three-dimensional reconstruction of EOS and CT of the spine were then generated. Using previous validated techniques, multiple scoliotic parameters in both modalities were determined. The agreement between the two modalities was compared using the Bland-Altman test, whereas the correlation was assessed by the intraclass correlation coefficient (ICC).ResultsThe mean ICC (prone and upright) of intra-rater/inter-rater reliabilities for the measured parameters were 0.985,0.961/0.969,0.903, respectively. Thoracic Cobb angles, intervertebral wedging and lumbar lordosis correlated significantly between upright EOS imaging radiographs (62.9 ± 9.3°,6.4 ± 2.9° and 48.8 ± 12.4°) and prone CT (47.3 ± 10.0°,5.8 ± 2.7° and 27.9 ± 11.4°; P < 0.001). The apical vertebral wedging and apical intervertebral disc wedging showed a good correlation among the two modalities (upright, 6.5 ± 3.5° and 6.4 ± 2.9°; prone, 6.5 ± 3.6° and 5.8 ± 2.7°; R2 ≥ 0.94; P < 0.01). Similarly, there was significant correlation in apical intervertebral rotation (R2 = 0.834; P < 0.01) between the prone CT (3.4 ± 3.0°) and upright EOS (3.8 ± 3.2°). In addition, the Cobb angle was significantly larger in upright EOS (62.9 ± 9.3°) than in prone CT (47.3 ± 10.0°, P < 0.01) position. There was significant underestimation on scoliotic severity in the prone position when compared with upright position.ConclusionsImportantly, the image acquisition and reconstruction from EOS can better provide accurate three-dimensional spinal representations of the scoliotic curvature in preoperative AIS patients. Moreover, our findings suggested that scoliotic curvatures in preoperative AIS patients can be largely represented by both imaging modalities despite the difference in body positioning.

Sexual dimorphism in the vertebral wedging of the human lumbar vertebrae and its importance as a comparative framework for understanding the wedging pattern of Neanderthals

Lumbar lordosis is a key element of the upright posture, being interpreted as a consequence of bipedal locomotion. There is consensus that the generic modern human pattern of metameric vertebral body wedging is sexually dimorphic in modern humans. However, recently published studies have compared this pattern with other hominins, such as Neanderthals. These tried to establish whether the (male) Neanderthal lumbar vertebrae express a pattern that falls within or outside the range of modern human males. In the present study, data collected by 3D landmarks of the lumbar vertebrae of modern humans from different geographic regions and Neanderthals (Ntotal = 505 individual vertebrae) are used to clarify this problem, observing a similarity of the generic human pattern but with some interspecific differences in the pattern in the upper and lower lumbar vertebrae. Thus, the vertebral bodies L1-L3 of Neanderthals are more ventrally-wedged than in male modern humans, whilst the L4-L5 vertebral bodies of Neanderthal show a more progressive increase of dorsal wedging than in modern human males. The obtained results support modularity of the lumbar spine with different patterns in its upper and lower parts, and add that human geographic variability must be taken into account when carrying out comparisons of Neanderthals and modern humans. Our findings make clear the need to investigate this matter in more detail including complementary methods. Finally, key issues concerning the choice of measurement are discussed and recommendations made about how much inference can be made about complex systems such as the lumbar spine based on single linear measurements.