A comparative cohort study of surgical approaches for adult spinal deformity at a minimum 2-year follow-up.

STUDY DESIGN: This study was a retrospective multi-center comparative cohort study. MATERIALS AND METHODS: A retrospective institutional database of operative adult spinal deformity patients was utilized. All fusions > 5 vertebral levels and including the sacrum/pelvis were eligible for inclusion. Revisions, 3 column osteotomies, and patients with < 2-year clinical follow-up were excluded. Patients were separated into 3 groups based on surgical approach: 1) posterior spinal fusion without interbody (PSF), 2) PSF with interbody (PSF-IB), and 3) anteroposterior (AP) fusion (anterior lumbar interbody fusion or lateral lumbar interbody fusion with posterior screw fixation). Intraoperative, radiographic, and clinical outcomes, as well as complications, were compared between groups with ANOVA and χ2 tests. RESULTS: One-hundred and thirty-eight patients were included for study (PSF, n = 37; PSF-IB, n = 44; AP, n = 57). Intraoperatively, estimated blood loss was similar between groups (p = 0.171). However, the AP group had longer operative times (547.5 min) compared to PSF (385.1) and PSF-IB (370.7) (p < 0.001). Additionally, fusion length was shorter in PSF-IB (11.4) compared to AP (13.6) and PSF (12.9) (p = 0.004). There were no differences between the groups in terms of change in alignment from preoperative to 2 years postoperative. There were no differences in clinical outcomes. While postoperative complications were largely similar between groups, operative complications were higher in the AP group (31.6%) compared to the PSF (5.4%) and PSF-IB (9.1) groups (p < 0.001). CONCLUSION: While there were differences in intraoperative outcomes (operative time and fusion length), there were no differences in postoperative clinical or radiographic outcomes. AP fusion was associated with a higher rate of operative complications.

Remodeling morphology of the subluxated osteotomy vertebra in closing-opening wedge osteotomy in ankylosing spondylitis: would the anterior bony beak blunt?

INTRODUCTION: To investigate the remodeling morphology of subluxated osteotomy vertebra in ankylosing spondylitis (AS) patients with thoracolumbar kyphosis after single-level closing-opening wedge osteotomy (COWO). MATERIALS AND METHODS: Standing lateral radiographs were taken to evaluate sagittal parameters including lumbar lordosis (LL), C7 sagittal vertical axis (SVA), global kyphosis (GK), sacral slope (SS), and pelvic tilt (PT). Radiographic parameters of the osteotomy vertebra included osteotomized vertebra angle (OVA), sagittal translation (ST), anterior height (AH), posterior height (PH), and middle height (MH) of the osteotomy vertebrae. Furthermore, lateral projection area of the vertebral body was also measured to evaluate the remodeling of the osteotomy vertebrae. RESULTS: Sixty AS patients who underwent single-level lumbar COWO with a minimal 2-year follow-up were included. The cohort consisted of 54 males and 6 females with an average age of 36.6 years. All patients were divided into two groups according to the development of vertebral subluxation (VS): 15 in VS group (ST ≥ 5 mm), 45 in non-VS group (ST < 5 mm). There was significant difference in the correction of GK, SVA, and the loss of correction of SVA between AS patients with and without VS. Significant difference in vertebra-related parameters regarding AH and OVA was found between VS group and non-VS group (P < 0.05). CONCLUSIONS: After COWO, new bone formation narrowing the gap and adaptive resorption of the anterior bony beak at the osteotomy level during follow-up was surprisingly favorable. However, the ability of spinal canal remodeling is limited in patients complicated with VS.

Risk factors for postoperative coronal decompensation in adult lumbar scoliosis after posterior correction with osteotomy.

INTRODUCTION: To determine potential risk factors for postoperative coronal imbalance following posterior osteotomy for adult scoliosis. MATERIALS AND METHODS: A total of 74 patients underwent osteotomy for rigid adult lumbar scoliosis. A group of 20 patients with postoperative coronal imbalance was identified. Clinical data and surgical strategies were compared to determine the risk factors, including age, gender, etiology, Cobb angle, preoperative coronal balance distance, direction of preoperative imbalance, T1 tilt, tilt of upper instrumented vertebra (UIV), UIV translation, location of UIV (T6 above or below), fusion to L5 or S1, lower instrumented vertebra (LIV) tilt, LIV rotation, screw density, osteotomy procedure (PSO or SPOs) and use of iliac screws. RESULTS: Comparison between patients with and without postoperative coronal imbalance showed that postoperative coronal imbalance occurred in older patients and those with degenerative scoliosis as the etiology, UIV above T6, preoperative LIV rotation, preoperative LIV tilt and preoperative coronal imbalance towards the convex side and who underwent Smith-Petersen osteotomy. All seven parameters were included in the logistic regression analysis. UIV above T6 (P = 0.010), LIV rotation (P = 0.012) and preoperative coronal imbalance towards the convex side (P = 0.005) were identified as risk factors for postoperative coronal imbalance after osteotomy. CONCLUSIONS: Patients with preoperative coronal imbalance towards the convex side (UIV above T6) and LIV rotation were more likely to develop coronal imbalance than those without risk factors. Older patients and those with degenerative scoliosis were also at a relatively higher risk of postoperative coronal imbalance.

Brace treatment for scoliosis secondary to chiari malformation type 1 or syringomyelia without neurosurgical intervention: A matched comparison with idiopathic scoliosis.

PURPOSE: To evaluate the effectiveness of brace treatment in patients with Chiari malformation type 1 (CM-1) or syringomyelia associated scoliosis without neurosurgical intervention. METHODS: This was a retrospective case-control study. 34 CM-1 or syringomyelia (CMS) patients who received brace treatment without neurosurgical intervention were recruited. Another 68 matched patients with idiopathic scoliosis who received bracing served as the control group. The matching criteria included gender, age (± 1 years), Risser sign (± 1 grade), initial curve magnitude (± 5°), curve patterns and follow-up time (± 6 months). Patients who encountered curve progression and scoliosis surgery were compared between different groups. RESULTS: Until the last visit, 16 (47%) patients in CMS group and 18 (26%) patients in IS group occurred curve progression; 9 (26%) patients and 15 (22%) patients underwent scoliosis surgery, respectively. Compared to idiopathic scoliosis, patients with CMS-associated scoliosis had a significantly higher rate of curve progression (P = 0.038). However, no significant difference was observed between two groups regarding to the rate of surgery (P = 0.867). Patients with combined CM-1 and syringomyelia had a higher rate of surgery than patients with isolated CM-1 or syringomyelia (P = 0.049). The double major curve pattern was identified as the risk factor for curve progression. CONCLUSION: Brace treatment is effective for CMS-associated scoliosis without neurosurgical intervention. Compared to idiopathic scoliosis, brace can provide similar prevention for scoliosis surgery in CMS patients, but slight or moderate curve progression may occur. Specifically, patients with combined CM-1 and syringomyelia should be followed closely with a higher expectation of curve progression.

Optimizing the fusion level for lenke 5C adolescent idiopathic scoliosis: is the S-line a validated and reproducible tool to predict coronal decompensation?

PURPOSE: To validate the predictability of S-line in Lenke 5C patients. METHODS: Lenke 5C patients with a minimum 2-year follow-up and with the lowest instrumented vertebra (LIV) at lower end vertebra were included. The S-line was defined as a line connecting the centers of concave-side pedicles of upper instrumented vertebra (UIV) and LIV on baseline films. The S-line tilt to right was defined as positive S-line status (S-line +) and tilt to left as S-line - status. Statistical analysis was performed between different subgroups. RESULTS: Among the 92 patients, 69 patients had a left lumbar curve and 23 patients had a right lumbar curve. For left curves, the S-line + status had a significantly higher incidence of both proximal and distal decompensation. However, for right curves, the S-line - status was the risk factor. Thus, we modified the definition of S-line: The value of S-line tilt for right curves was opposite to that for left curves. Patients with modified S-line + showed a significantly higher incidence of both proximal and distal decompensation in Lenke 5C patients with both left and right curves (p < 0.001 and p = 0.010). In UEV group, patients with modified S-line + showed significantly higher incidence of proximal decompensation (P = 0.001). However, in UEV-1 group, the incidence of proximal decompensation was not statistically affected by modified S-line + (P = 0.281). CONCLUSION: Modified S-line + is a validated risk factor that predisposed to post-operative coronal decompensation in Lenke 5C AIS patients. Selecting UIV at one level caudal to UEV could be a possible solution if the modified S-line was positive.

Quality of Life During Pregnancy, Caesarean Section Rate, and Anesthesia in Women with a History of Anterior Correction Surgery for Lumbar Scoliosis: A Case-Control Study.

BACKGROUND This study investigated the prevalence and severity of low back pain (LBP), caesarean section (C-section) rate, and the anesthesia approaches among lumbar scoliosis patients undergoing anterior correction surgery, and compared them with a healthy control cohort. MATERIAL AND METHODS The inclusion criteria for adolescent idiopathic scoliosis (AIS) patients were: presence of lumbar scoliosis, history of 1 or more pregnancies after surgery, and underwent anterior-only surgery. Healthy women with a history of 1 pregnancy were included as the control group. We recorded the type of delivery, neonatal birth weight, and perinatal complications. The quality of life was also evaluated. RESULTS New-onset LBP was reported in 65.6% of AIS patients, significantly higher than in the control group (p<0.001). C-section was performed in 11 scoliosis patients (34.4%) and 25 healthy controls (31.25%), and the rates were not significantly different between groups (P=0.75). No serious perinatal complications were reported in either group. General anesthesia was used for all C-section AIS patients. The rate of successful neuraxial anesthesia in the control group was significantly higher (P<0.001). CONCLUSIONS Compared with the healthy control group, lumbar AIS patients did not experience a higher risk of perinatal complications or C-section rate after anterior surgical correction, but general anesthesia was more commonly used than neuraxial regional anesthesia. LBP was more frequently observed in the post-operative AIS patients.

Spino-femoral muscles affect sagittal alignment and compensatory recruitment: a new look into soft tissues in adult spinal deformity.

OBJECTIVE: To quantify muscle characteristics (volumes and fat infiltration) and identify their relationship to sagittal malalignment and compensatory mechanism recruitment. METHODS: Female adult spinal deformity patients underwent T1-weighted MRI with a 2-point Dixon protocol from the proximal tibia up to the T12 vertebra. 3D reconstructions of 17 muscles, including extensors and flexors of spine, hip and knee, were obtained. Muscle volume standardized by bone volume and percentage of fat infiltration (Pfat) were calculated. Correlations and regressions were performed. RESULTS: A total of 22 patients were included. Significant correlations were observed between sagittal alignment and muscle parameters. Fat infiltration of the hip and knee flexors and extensors correlated with larger C7-S1 SVA. Smaller spinal flexor/extensor volumes correlated with greater PI-LL mismatch (r = - 0.45 and - 0.51). Linear regression identified volume of biceps femoris as only predictor for PT (R2 = 0.34, p = 0.005) and Pfat of gluteus minimus as only predictor for SVA (R2 = 0.45, p = 0.001). Sagittally malaligned patients with larger PT (26.8° vs. 17.2°) had significantly smaller volume and larger Pfat of gluteus medius, gluteus minimus and biceps femoris, but similar values for gluteus maximus, the hip extensor. CONCLUSION: This study is the first to quantify the relationship between degeneration of spino-femoral muscles and sagittal malalignment. This pathoanatomical study identifies the close relationship between gluteal, hamstring muscles and PT, SVA, which deepens our understanding of the underlying etiology that contributes to adult spinal deformity.

Procalcitonin and N-Terminal Pro-B-Type Natriuretic Peptide for Prognosis in Septic Acute Kidney Injury Patients Receiving Renal Replacement Therapy.

BACKGROUND: Sepsis is a complex clinical syndrome leading to severe sepsis and septic shock. It is very common in the intensive care unit with high mortality. Thus, judging its prognosis is extremely important. Procalcitonin (PCT) and -N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels are commonly elevated in sepsis patients, but only a few are discussed in the septic acute kidney injury patients (AKI) who received renal replacement therapy (RRT). Our study is aimed at investigating the prognostic value of PCT and NT-proBNP in septic AKI patients who received RRT. METHODS: This was a retrospective study of septic AKI patients who underwent RRT in a Chinese university hospital. All enrolled patients tested PCT and NT-proBNP at RRT initiation. PCT and NT-proBNP levels were compared between the survivors and non-survivors. Receiver operating characteristic (ROC) curves of the 2 biomarkers were performed for predicting in-hospital mortality. According to the median value of PCT (16.2 ng/mL) and NT-proBNP (10,271 pg/mL), patients were divided into 4 groups (low PCT and low NT-proBNP; high PCT and low NT-proBNP; low PCT and high NT-proBNP; high PCT and high NT-proBNP). The Kaplan-Meier survival curves were used to analyze the 28-day survival rate in the 4 groups. RESULTS: A total of 81 patients were enrolled in the study. Of which, 48 (59.3%) patients died during hospitalization. The median of NT-proBNP in non-survivors was significantly higher than in survivors (p = 0.001), while PCT had no significant difference (p = 0.412). The area under the ROC curve of PCT and NT-proBNP for predicting in-hospital mortality was 0.561 (95% CI 0.426-0.695) and 0.729 (95% CI 0.604-0.854). Kaplan-Meier survival curve analysis showed that increased NT-proBNP level was associated with 28-day mortality while combined with PCT there was no statistical difference in 4 different level groups. CONCLUSION: NT-proBNP has a certain predictive value for the prognosis in septic AKI patients who received RRT. It seems that the initial PCT value for prognosis is limited. The combination of PCT and -NT-proBNP to evaluate the prognosis in these critically ill patients is currently unclear.

Long fusion to the pelvis with S2-alar-iliac screws can induce changes in pelvic incidence in adult spinal deformity patients: analysis of predictive factors in a retrospective cohort.

PURPOSE: To verify whether pelvic incidence (PI) would change in adult spinal deformity (ASD) patients who underwent long instrumentation using S2-alar-iliac (S2AI) screws and to identify factors associated with the change in PI. METHODS: We retrospectively reviewed all patients who underwent spinal surgery using S2AI screws between November 2014 and January 2017 at our institution. Patients aged 20 years or above with available radiographs were included. According to the change in PI, patients were divided into two groups, group C: PI variance reached 5 or more degrees postoperatively and group NC: PI changed less than 5°. RESULTS: A total of 47 patients (3 males, 44 females; mean age, 52.47 ± 15.80 years) were included in this study. PI significantly decreased from 51.25° ± 14.80° to 40.43° ± 14.23° in group C (n = 26), with a mean change in 11.52° ± 6.17° (P < 0.05), but changed from 47.00° ± 13.18° to 46.57° ± 13.71° in group NC without statistical significance. Intergroup analysis showed that change in PI, preoperative PI-LL, preoperative LL, preoperative SVA, and postoperative PT were significantly different between both groups. Correlation analysis showed that the change in PI and preoperative LL and PI were significantly associated. The formula provided by the regression analysis was ΔPI = - 3.108 - 0.11PreLL + 0.211PrePI. CONCLUSIONS: Our study showed that PI decreased in 55% of ASD patients after spinal surgery using S2AI screws. Greater preoperative PI-LL mismatch and PI, as well as lumbar kyphosis, were associated with postoperative change in PI. These slides can be retrieved under Electronic Supplementary Material.

Sequential correction technique to avoid postoperative global coronal decompensation in rigid adult spinal deformity: a technical note and preliminary results.

PURPOSE: This study aims to evaluate this new sequential correction technique for preventing postoperative coronal imbalance. METHODS: Adult Spinal deformity (ASD) patients were stratifies into two types: primary thoracolumbar/lumbar (TL/L) curve with compensatory lumbosacral (LS) curve (Type I) and primary LS curve with compensatory TL/L curve (Type II): for Type I patients: correction of major TL/L curve and one- or two-level segmental rod installed at the convexity of the TL/L curve, L4-S1 TLIF to correct fractional curve and a short rod installed on the contralateral side and installation of long rods; for Type II patients: horizontalize L4 and L5, short rod installation at the convexity of the LS curve, distraction of curve with regional rod and installation of long rods. ASD patients were enrolled with inclusion criteria: with pre-op TL/L Cobb angle more than 30°, with pelvic fixation and with UIV over T10. Radiographic parameters were analyzed. RESULTS: Twenty-one patients were recruited (14 patients Type I and 7 Type II patients). Both Cobb angle and coronal offset were significantly improved after surgery. In Type I patients, Cobb angle was improved from 50.48° to 26.91° and coronal offset from 2.94 to 0.95 cm; in Type II patients, Cobb angle was improved from 61.42° to 28.48° and coronal offset from 2.82 to 1.38 cm. In the 10 patients with baseline coronal imbalance, 9 were corrected to coronal balance after surgery. CONCLUSION: The sequential correction technique allows decomposing the complex correction surgery into several steps, and each step focuses only on one task. It can also reduce the difficulty of rod installation due to the separated maneuvers and multi-rod system. LEVEL OF EVIDENCE: IV These slides can be retrieved under Electronic Supplementary Material.

Lumbosacral stress and age may contribute to increased pelvic incidence: an analysis of 1625 adults.

PURPOSE: While there is a consensus that pelvic incidence (PI) remains constant after skeletal maturity, recent reports argue that PI increases after 60 years. This study aims to investigate whether PI increases with age and to determine potential associated factors. METHODS: 1510 patients with various spinal degenerative and deformity pathologies were enrolled, along with an additional 115 asymptomatic volunteers. Subjects were divided into six age subgroups with 10-year intervals. RESULTS: PI averaged 54.1° in all patients. PI was significantly higher in the 45-54-year age group than 35-44-year age group (55.8° vs. 49.7°). There were significant PI differences between genders after age 45. Linear regression revealed age, gender and malalignment as associated factors for increased PI with R 2 of 0.22 (p < 0.001). CONCLUSIONS: PI is higher in female patients and in older patients, especially those over 45 years old. Spinal malalignment also may have a role in increased PI due to increased L5-S1 bending moment.

Three types of sagittal alignment regarding compensation in asymptomatic adults: the contribution of the spine and lower limbs.

PURPOSE: A comprehensive understanding of normative sagittal profile is necessary for adult spinal deformity. Roussouly described four sagittal alignment types based on sacral slope, lumbar lordosis, and location of lumbar apex. However, the lower limb, a newly described component of spinal malalignment compensation, is missing from this classification. This study aims to propose a full-body sagittal profile classification in an asymptomatic population based on full-body imaging. METHODS: This is a retrospective analysis of a prospective single-center study of 116 asymptomatic volunteers. Cluster analysis including all sagittal parameters was first performed, and then ANOVA was performed between sub-clusters to eliminate the non-significantly different parameters. This loop was repeated until all parameters were significantly different between each sub-cluster. RESULTS: Three types of full-body sagittal profiles were finalized according to cluster analysis with ten radiographic parameters: hyperlordosis type (77 subjects), neutral type (28 subjects), and compensated type (11 subjects). Radiographic parameters included knee angle, pelvic shift, pelvic angle, PT, PI-LL, C7-S1 SVA, TPA, T1 slope, C2-C7 angle, and C2-C7 SVA. Age was significantly different across compensation types, while BMI and gender were comparable. Age-matched subjects were randomly selected with 11 subjects in each type. ANOVA analysis revealed that all parameters but PT and C2-C7 angle remained significantly different. CONCLUSIONS: The current three compensation types of full-body sagittal profiles in asymptomatic adults included significant changes from cervical region to knee, indicating that subjects should be evaluated with full-length imaging. All three types exist regardless of age, but the distribution may vary.

Could pelvic parameters determine optimal postoperative thoracic kyphosis in Lenke type 1 AIS patients?

BACKGROUND: A proper restoration of sagittal alignment is essential in AIS patients, but few studies provided a formula to predict an optimal surgical thoracic kyphosis (TK) gain in adolescent idiopathic scoliosis (AIS) patients. A formula was recently proposed (LL = (PI+TK)/2 + 10) to predict the optimal lumbar lordosis (LL) in adult spinal deformity patients, which has not been validated in adolescents. The aim of this study is to establish a formula with TK and pelvic parameters in normal adolescents and predict an optimal TK with this formula pre- and post-operatively in Lenke 1 AIS patients. METHODS: A total of 60 asymptomatic adolescents were used to validate the proposed formula. The subject was considered to match with the formula, if the difference between the virtual TK and the theoretical TK was less than 10°. Then regression analysis was performed to establish a new formula to predict TK in adolescents. The predictive efficiency of the new formula was also validated in 40 Lenke 1 AIS patients. RESULTS: Of the 60 asymptomatic adolescents, only 26 (43.33%) asymptomatic adolescents matched with the adjusted formula: TK = 2 × (LL-10)-PI. The paired t test revealed a significantly different theoretical TK (tTK) compared to the virtual TK (41.23 ± 18.29° vs. 24.80 ± 8.75°, P < 0.001). Multiple linear regression showed that TK had a relationship with LL, SS and age (R2 = 0.331): TK = - 0.785 × LL-0.843 × SS + 0.858 × age + 3.754. There were 27 (67.50%), 32 (80.00%) and 35 (87.50%) Lenke 1 AIS patients matched this formula preoperatively, postoperatively and at the last follow-up. CONCLUSION: Our results revealed that the predictive formula for sagittal alignment for adults was not applicable in adolescents. This study established a new predictive formula for TK based on asymptomatic adolescents. In Lenke 1 AIS patients, post-op TK in 87.5% of patients matched the predictive value, indicating that the new formula can be considered as a reference when making a surgery strategy.

Inhibition of Reticulon-1A-Mediated Endoplasmic Reticulum Stress in Early AKI Attenuates Renal Fibrosis Development.

Several animal studies have shown an important role for endoplasmic reticulum (ER) stress in AKI, whereas human studies are lacking. We recently reported that Reticulon-1A (RTN1A) is a key mediator of ER stress and kidney cell injury. Here, we investigated whether modulation of RTN1A expression during AKI contributes to the progression to CKD. In a retrospective study of 51 patients with AKI, increased expression of RTN1A and other ER stress markers were associated with the severity of kidney injury and with progression to CKD. In an inducible tubular cell-specific RTN1A-knockdown mouse model subjected to folic acid nephropathy (FAN) or aristolochic acid nephropathy, reduction of RTN1A expression during the initial stage of AKI attenuated ER stress and kidney cell injury in early stages and renal fibrosis development in later stages. Treatment of wild-type mice with tauroursodeoxycholic acid, an inhibitor of ER stress, after the induction of kidney injury with FA facilitated renoprotection similar to that observed in RTN1A-knockdown mice. Conversely, in transgenic mice with inducible tubular cell-specific overexpression of RTN1A subjected to FAN, induction of RTN1A overexpression aggravated ER stress and renal injury at the early stage and renal fibrosis at the late stage of FAN. Together, our human and mouse data suggest that the RTN1A-mediated ER stress response may be an important determinant in the severity of AKI and maladaptive repair that may promote progression to CKD.

Prediction of respiratory function in patients with severe scoliosis on the basis of the novel individualized spino-pelvic index.

OBJECTIVE: Our study aimed to evaluate the pulmonary function of patients with severe scoliosis after correcting standing height with spino-pelvic index (SPI). METHODS: Inclusion criteria: (1) with a coronal Cobb angle of more than 90°; (2) diagnosed as congenital (CS) or idiopathic scoliosis (IS); (3) aged between ten and 20 years; (4) with pulmonary function test (PFT) at the primary consultation. Patients with previous surgical intervention, with angular kyphosis, and with neuromuscular disease were excluded. Length of spine (LOS), height of spine (HOS), and height of pelvis (HOP) were measured on coronal films. SPI was defined as the ratio between LOS and HOP. The corrected body height was calculated: corrected body height = body height + (SPI × HOP - HOS). The PFTs included the following parameters: VCmax, FVC, FVC% predicted, FEV1, FEV1% predicted, PEF, and MVV. PFT results were recalculated using the corrected body height. RESULTS: Thirty patients were diagnosed as IS and 27 as CS with average Cobb angles of 99.88° ± 11.83 and 98.06° ± 14.27, respectively. Significant differences were observed in VCmax and FVC between IS and CS patients (P < 0.05). All the corrected PFT parameters were significantly lower than the original PFT parameters (P < 0.05). CONCLUSION: For the first time, this study proposed a method to predict pulmonary function of patients with severe scoliosis using SPI, as an age-independent parameter in normal adolescents. After body height correction, pulmonary function of patients with severe scoliosis was found to be significantly decreased, indicating that pulmonary function impairment was underestimated in patients with severe scoliosis when evaluating pulmonary function with arm span.

Do the disc degeneration and osteophyte contribute to the curve rigidity of degenerative scoliosis?

BACKGROUND: The factors associated with lateral curve flexibility in degenerative scoliosis have not been well documented. Disc degeneration could result in significant change in stiffness and range of motion in lateral bending films. The osteophytes could be commonly observed in degenerative spine but the relationship between osteophyte formation and curve flexibility remains controversial. The aim of the current study is to clarify if the disc degeneration and osteophyte formation were both associated with curve flexibility of degenerative scoliosis. METHODS: A total of 85 patients were retrospectively analyzed. The inclusion criteria were as follow: age greater than 45 years, diagnosed as degenerative scoliosis and coronal Cobb angle greater than 20°. Curve flexibility was calculated based on Cobb angle, and range of motion (ROM) was based on disc angle evaluation. Regional disc degeneration score (RDS) was obtained according to Pfirrmann classification and osteophyte formation score (OFS) was based on Nanthan classification. Spearman correlation was performed to analyze the relationship between curve flexibility and RDS as well as OFS. RESULTS: Moderate correlation was found between RDS and curve flexibility with a Spearman coefficient of -0.487 (P = 0.009). Similarly, moderate correlation was observed between curve flexibility and OFS with a Spearman coefficient of -0.429 (P = 0.012). Strong correlation was found between apical ROM and OFS compared to the relationship between curve flexibility and OFS with a Spearman coefficient of -0.627 (P < 0.001). CONCLUSIONS: Both disc degeneration and osteophytes formation correlated with curve rigidity. The pre-operative evaluation of both features may aid in the surgical decision-making in degenerative scoliosis patients.

An effective delivery vehicle of demineralized bone matrix incorporated with engineered collagen-binding human bone morphogenetic protein-2 to accelerate spinal fusion at low dose.

The aim of this study was to investigate the feasibility and efficacy of a new delivery matrix using demineralized bone matrix (DBM) incorporated with collagen-binding bone morphogenetic protein-2 (CBD-BMP-2) in the rat inter-transverse spinal fusion model. Sixty rats undergoing posterolateral (inter-transverse) spinal fusion were divided into 3 groups according to the fusion materials containing different components (n = 20 per group). Group A were implanted with DBM, Group B with combination of DBM and BMP-2 and Group C with combination of DBM and CBD-BMP-2. After surgery, the spinal fusion of all the rats was assessed by plain radiography, CT + 3D reconstruction, manual palpation and histological evaluation. Significant difference was found in terms of solid fusion rate among the three groups, with 95% in Group C, 65% in Group B and 0% in Group A (P < 0.001). Compared with Groups B and A, new bone formation was observed earlier and was obvious larger, trabecular bone microarchitecture assessment was better and bone mineral density was statistically larger in Group C. In addition, more newly woven bone and osteocytes were shown by histological evaluation in Group C at 4 weeks post-operation. The present study showed CBD domain could help BMP-2 to improve the efficiency of posterolateral spinal fusion. DBM scaffold activated by collagen-binding BMP-2 was a feasible and promising bone repair vehicle. The present study showed better results in terms of plain radiography, CT + 3D reconstruction, manual palpation and histological evaluation in the rat inter-transverse spinal fusion model using DBM+CBD-BMP-2, compared with DBM+BMP-2 and DBM alone, indicating DBM scaffold activated by collagen-binding BMP-2 was a feasible and promising bone repair vehicle.

Vertebral coplanar alignment technique: a surgical option for correction of adult thoracic idiopathic scoliosis.

PURPOSE: Previous studies have demonstrated vertebral coplanar alignment (VCA) as an effective surgical option for adolescent idiopathic scoliosis (AIS). The purpose of this study is to analyze the outcome of VCA for the surgical correction of adult idiopathic scoliosis (AdIS). METHODS: 35 AdIS patients (mean age: 24.2 years) undergoing VCA-instrumentation were reviewed. The main thoracic curve and thoracic kyphosis (TK, T5-T12) were evaluated preoperatively, immediate postoperatively, and at the final follow-up (>1 year). All patients were stratified by the TK modifier before surgery: "+" (TK, >40°), "-" (TK, <10°), and "N" (TK, 10°-40°) for normal. The apical vertebral body-to-rib ratio (AVB-R), rib hump (RH), and rotational angle to sacrum (RAsac) were measured to assess the correction of rotational deformity. Quality of life was evaluated with SRS-20 questionnaires. RESULTS: The main thoracic curve (59.1° vs. 19.3°, P < 0.001) and rotational deformity (AVB-R: 2.4 vs. 1.7 %, P < 0.001, RH: 34.9 vs. 19.1 mm, P < 0.001, RAsac: 19.6° vs. 11.9°, P < 0.001) were significantly reduced with surgery. Sagittal deformity improved significantly in group "+" (51.4° vs. 31.6°, P < 0.001) and group "-" (6.2° vs. 20.1°, P < 0.001), while no significant postoperative change in TK was observed in group "N" (23.5° vs. 26.3°, P = 0.270). Patients were followed for an average of 18.7 months with no significant loss of correction. SRS scores improved greatly from 57.7 preoperatively to 71.6 at the final follow-up. CONCLUSIONS: VCA can be effectively used for the correction of the coronal and rotational deformity, with better sagittal profile restoration in adult thoracic idiopathic scoliosis with sagittal malalignment.

Halo-gravity traction combined with assisted ventilation: an effective pre-operative management for severe adult scoliosis complicated with respiratory dysfunction.

PURPOSE: To investigate the change of pulmonary function in adult scoliosis patients with respiratory dysfunction undergoing HGT combined with assisted ventilation. METHODS: 21 adult patients were retrospectively reviewed with a mean age of 26.2 years. Inclusion criteria were as follows: age over 18 years old; coronal Cobb angle greater than 100°; with respiratory failure; and duration of HGT more than 1 month. All patients underwent respiratory training. RESULTS: The Cobb angle averaged 131.21° and was reduced to 107.68° after HGT. Significantly increased mean forced vital capacity (FVC) was found after HGT (P = 0.003) with significantly improved percent-predicted values for FVC (P < 0.001). Meanwhile, significantly increased forced expiratory volume in 1 s (FEV1) was also observed (P < 0.001) with significantly improved percent-predicted values for FEV1 (P = 0.003) after HGT. CONCLUSION: The results of our study revealed that combined HGT and assisted ventilation would be beneficial to pulmonary function improvement in severe adult scoliosis cases, most of which were young adults.

Evaluation of demographic factors affecting predictability of the sacro-femoral-pubic angle in healthy adolescents.

The objectives of the present study are to evaluate the correlation between pelvic tilt (PT) and the sacro-femoral-pubic (SFP) angle in Asian healthy adolescents, to provide the normal value of SFP angle as reference data in Asian adolescents, and to clarify whether the predictability of PT could be affected by gender and ontogenesis. In all, 100 girls with a mean age of 12.66 years (range 8-18 years) and 70 boys with a mean age of 13.35 years (range 8-18 years) were recruited in this retrospective study. SFP angles and PT were obtained on long-cassette standing upright radiographs. The subjects were grouped based on age. Independent-sample t-tests were performed to compare age, SFP angle, and PT between genders. In all age groups, the relationship between SFP angle and PT was analyzed by Pearson's correlation analysis and linear regression analysis, respectively. Reliability analysis showed high intra- and inter-observer agreements in PT and SFP, with an intra-class correlation coefficient (ICC) > 0.8. SFP angle averaged 71.64° ± 4.91 in all the normal subjects, of which the mean PT was 72.03°± 4.94 in the female group and 71.09°± 4.83 in the male group. SFP and PT were strongly correlated in all the age groups according to Pearson's correlation analysis. The overall coefficient was 0.679 in girls and 0.584 in boys. The present study is the first to describe the normal value of SFP angle in healthy Asian adolescents to serve as a reference data. In all age groups, SFP angles can be used to predict PT when lateral radiographs do not permit assessment of PT. The predictability of SFP angle for PT was not affected by gender or maturation status.