Coronal Curve Magnitude Research Articles

Vertebral Body Tethering Surgery

Background: Much enthusiasm has been generated around vertebral body tethering (VBT) as an alternative to fusion treatment. However, the majority of studies have shown little difference between coronal curve magnitude on the first postoperative erect radiograph and that at final follow-up, suggesting that VBT is not consistently modulating spine growth in a manner that substantially affects coronal curve magnitude. Methods: All patients with adolescent idiopathic scoliosis (AIS) who underwent VBT between December 2013 and June 2020 and subsequently had at least 2 years of follow-up in a multicenter registry were reviewed. The change in coronal curve magnitude was calculated by subtracting the magnitude at the time of final follow-up from that on the first postoperative erect radiograph. A change of <5° was considered to be within normal measurement variability. Results: One hundred and ten patients met the inclusion criteria (racial breakdown: 94 White, 6 Black/African American, 3 Asian, 2 Middle Eastern, 1 mixed race, and 4 uncertain/unspecified; ethnicity: 87 not Hispanic or Latino, 1 Hispanic/Latino, and 22 did not report their ethnicity). Their mean age was 12.9 years (standard deviation [SD], 1.3 years) and the mean follow-up was 3.7 years (range, 2.0 to 6.9 years). A mean of 6.6 levels were tethered. The preoperative mean coronal curve magnitude was 51.0° (range, 32° to 75°), which corrected to a mean of 27.3° (range, 10° to 53°) on the first postoperative erect radiograph. At the time of final follow-up, the mean coronal curve magnitude was 30.9° (range, −50° to 69°), and 49.1% (54) of the 110 curves were stable (the coronal curve magnitude at final follow-up was within 5° of that on the first postoperative erect radiograph). A total of 42.7% (47) had >5° of increase in coronal curve magnitude following the initial postoperative erect radiograph, whereas 8.2% (9) showed a >5° increase during the follow-up period. Five of the 9 patients (4.5% of the series) had a >10° decrease, with 2 of the 5 having overcorrection, ending up with 31° and 50° curves in the opposite direction. Conclusions: Although VBT holds promise and many (49.1%) of the 110 curves in this series remained stable from the first postoperative erect to the final follow-up radiograph, only 9 demonstrated a decrease in coronal curve magnitude over time, including 2 that overcorrected. Further research is needed to identify the factors differentiating among patients who had curve progression, did not have progression, or had overcorrection to determine which patients are more likely to benefit from VBT. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Outcome of distraction-based growing rods at graduation: a comparison of traditional growing rods and magnetically controlled growing rods.

Distraction-based growing rods have been considered as an alternative surgical option for the operative treatment of EOS. TGR has been challenged by MCGR, which is reported to have the advantage of non-invasive lengthening with fewer planned returns to theatre. This study explores the radiographic outcomes, Unplanned Returns to the Operating Room (UPROR) and complication profile of both the procedures at the end of the planned growing rod treatment with either TGR or MCGR. We included all the EOS cases from the PSSG database that underwent either TGR or MCGR with spine-based proximal anchors, followed up to the time of graduation. Any crossover or hybrid procedures were excluded. 549 patients (409 TGR and 140 MCGR) were eligible for review. We measured the coronal curve magnitude, Kyphosis, T1-T12, T1-S1 and L1-S1 lengths at 4 time points (before and after the index surgery and before and after the definitive surgery). The TGR group were slightly younger at the time of the index procedure (7years for TGR vs. 8.5years for MCGR, p < 0.001). We noted an improvement in all radiological parameters after the growing rod implantation. The spinal lengths increased through the lengthening period, while the coronal curve magnitude and the kyphosis increased. The kyphosis normalized following the final fusion, the coronal curve magnitude reduced further with a further increase in spinal lengths. The final follow-up from the time of the index implantation to the definitive surgery was 5.1years (IQR 3.8) in TGR and 3.5years (IQR 1.65) in the MCGR groups. The total number of complications was fewer in the MCGR group. The overall risk of UPROR was lower in the MCGR group and implant breakage was less in the MCGR group by 4.7 times. This study confirms the equivalence of both the distraction-based growing rods systems from the radiological stand-point, during the lengthening phase and at the time of the definitive surgery. The TGR was more kyphogenic during the lengthening period. The complications and UPROR were fewer in the MCGR groups.

Back pain in adolescent idiopathic scoliosis: frequency and risk factors

PurposeAlthough back pain is commonly reported in patients with adolescent idiopathic scoliosis (AIS), factors that influence the presence and severity of back pain in AIS, including curve-specific variables, have not been well studied. This study aims to describe the prevalence and severity of back pain in AIS patients and determine the extent to which patient characteristics, including curve-specific factors, are associated with a higher risk of back pain in AIS.MethodsThe study was a retrospective medical records review of adolescents (aged 10–17 years) diagnosed with AIS between 01/01/2018 and 12/31/2021 at an academic tertiary children’s hospital. Patients with previous spine surgery were excluded. Variables collected included demographics (age, sex, race, insurance), Lenke classification, major coronal curve, back pain-related information, Risser stage, vitamin D levels, post-diagnosis brace utilization, physical therapy or chiropractic treatment, and surgery.ResultsA total of 891 AIS patients were included in the analysis. The sample was predominantly female (73.3%) and insured by Medicaid (57.8) with a mean age of 12.8 years. The mean major coronal curve was 26.3 degrees. Most patients had Lenke type 1 (47%) and type 5 (41%) curves. Nearly half of patients reported back pain (48.5%) with average pain severity in the low-to-moderate range (4.7) on FACES pain scale (0–10). Among those who reported back pain, 63.2% specified a location with the majority reporting pain in the lumbar region (56%) and, less commonly, in the thoracic (39%) and scapular (8%) regions. Lumbar pain was associated with significantly higher pain intensity (p = 0.033). Additionally, the location of pain reported was associated with location of major coronal curve (p < 0.0001). No association was observed between pain presence and vitamin D deficiency (p = 0.571, n = 175), major coronal curve magnitude (p = 0.999), Lenke curve type (p = 0.577), and sex (p = 0.069). Older patients, those insured by Medicaid, and those with higher Risser scores were more likely to report pain scores (p = 0.001 for all).ConclusionNearly half (48%) of newly diagnosed AIS patients experience back pain which is higher than the prevalence of 33% seen in the general adolescent population. Pain was more prevalent among patients over the age of 13, with heavier body weight, and those insured by Medicaid. Pain was most commonly reported in the lumbar region, especially among patients with lumbar curves. This information can be helpful in counseling AIS patients, though further investigations are needed, especially to determine the underlying causes of back pain in AIS and to elucidate the discrepancy in pain between patients with Medicaid and commercial insurance.Level of evidence.Prognostic Study Level II.

Pre-contoured patient-specific rods result in superior immediate sagittal plane alignment than surgeon contoured rods in adolescent idiopathic scoliosis.

Adolescent idiopathic scoliosis (AIS) surgery typically involves posterior spinal fusion (PSF) using rods contoured by the surgeon, which may be time-consuming and may not reliably restore optimal sagittal alignment. However, pre-contoured patient-specific rods may more optimally restore sagittal spinal alignment. This study evaluates the radiographic outcomes of AIS patients who underwent PSF utilizing surgeon contoured vs. pre-contoured rods. This is a retrospective cohort study of AIS patients who underwent PSF with either surgeon contoured or pre-contoured rods. Demographics, Lenke classification, fused levels, osteotomies, estimated blood loss (EBL), and surgical time were also obtained via chart review. Coronal curve magnitude, T5-T12 thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), PI-LL mismatch, and T1 pelvic angle (TPA) were obtained pre-operatively, postoperatively and at last follow up. Outcome measures included rate of achievement of postoperative radiographic alignment goals (TK between 20 and 40 degrees, PI-LL mismatch within 10 degrees, and TPA <14 degrees). Predicted post-operative sagittal alignment was also compared with observed measurements. Student's and paired t-tests were performed to determine significant mean differences for continuous variables, and chi-square for categorical variables. No differences were found in demographics, Lenke classification, preop radiographic measurements, fused levels, osteotomies, EBL, and surgical time in the surgeon contoured cohort (n=36; average follow up 11.3 months) and pre-contoured cohort (n=22; average follow up 9.7 months). At last follow up, 95.5% of patients with pre-contoured rods vs. 61.1% of patients with surgeon contoured rods (P=0.004) met TK goal. During assessment of first standing postoperative X-ray, 72.7% of patients with pre-contoured rods vs. 33.3% of patients with surgeon contoured rods met PI-LL mismatch goal (P=0.004). Other radiographic measurements were similar. Artificial intelligence (AI) predicted and observed differences for the pre-contoured group were 3.7 for TK (P=0.005), -7.6 for PI-LL mismatch (P=0.002), and -2.6 for TPA (P=0.11). AI and pre-contoured rods help achieve global sagittal balance with high accuracy and improved kyphosis restoration and PI-LL mismatch than surgeon contoured rods in AIS patients.

Is the morphology of the apical pedicles influenced by apical rotation or the coronal curve magnitude in adolescent idiopathic scoliosis?: a radiographic assessment.

Asymmetry in pedicle anatomy is most distinctly noted around the apex of the curve. The correlation of pedicle dysmorphia with apical vertebral rotation (AVR) and coronal Cobb angle (CCA) has not been studied. To establish whether pedicle dysmorphism is linked to curve magnitude CCA and the AVR in adolescent idiopathic scoliosis (AIS). Preoperative plain whole spine standing radiographs and non-contrast computed tomography (CT) scans of 25 AIS patients that were operated at a single centre from 2013 to 2019 were retrospectively reviewed by 3 independent co-investigators. CCA was noted on the standing radiograph, whereas the AVR was measured on the axial cuts of CT scan. Pedicle morphometric measurements were performed for apical and periapical pedicles. These included apical vertebra (when present), 2 vertebrae above (U1 and U2) and below (B1 and B2) the apex vertebra/disc. The pedicle morphometric measurements were performed on CT scans. We assessed the transverse pedicle diameter, transverse cancellous channel diameter, sagittal pedicle diameter, pedicle length and pedicle axis length. Correlation tests between various pedicle morphometric measurements, AVR and the curve magnitude (Cobb angle) was performed by the Pearson correlation test. The apex of the major curve was in the thoracic spine in 20 patients, thoracolumbar in three patients and in the lumbar spine in two patients. The mean Cobb angle was 61.5 ± 9.3° and the mean AVR was 28.4 ± 17.8°. A positive correlation was noted with the AVR for U1 concave pedicle length (r = 0.45, p = 0.03), pedicle axis length of the U2 concave pedicle (r = 0.6, p = 0.04), transverse pedicle diameter of the convex apical vertebrae (r = 0.82, p = 0.00009) and the convex apical transverse pedicle diameter (r = 0.80, p = 0.002). A negative correlation with the AVR was noted for U2 convex pedicle length (r = -0.51, p = 0009), transverse cancellous channel diameter of the U2 concave pedicle (r = -0.42, p = 0.04) and apical concave pedicle (r = -0.78, p = 0.002) and the sagittal pedicle diameter for the convex pedicle of U2 (r = -0.45, p = 0.03) and apex(r = -0.59, p = 0.04). The Cobb angle did not show a significant correlation with any of the pedicle measurements at any of the levels on the convex and the concave sides. Pedicle asymmetry and dysmorphism demonstrate a morphometric association with the apical vertebral rotation than the curve magnitude. The pedicle length and the pedicle axis length increase on the concave apical and periapical region with increase in AVR. The transverse cancellous channel diameter significantly decreases on the concave apical region with the increase in AVR. The sagittal pedicle diameter decreases on the convex side with the increase in AVR.

Pain After Anterior Vertebral Body Tethering: Incidence, Risk Factors, and Timing.

Retrospective case series. To examine the incidence and risk factors for postoperative pain following anterior vertebral body tethering (AVBT) for adolescent idiopathic scoliosis (AIS). Up to 78% of patients with AIS report preoperative pain; it is the greatest patient concern surrounding surgery. Pain significantly decreases following posterior spinal fusion, but pain following AVBT is poorly understood. We retrospectively reviewed 279 patients with a two-year follow-up after AVBT for AIS. We collected demographic, radiographic, and clinical data pertinent to postoperative pain at each time interval of preoperative and postoperative visits (6wk, 6mo, 1y, and annually thereafter). Within our cohort, 68.1% of patients reported preoperative pain. Older age ( P =0.014) and greater proximal thoracic ( P =0.013) and main thoracic ( P =0.002) coronal curve magnitudes were associated with preoperative pain. Pain at any time point > 6 weeks postoperatively was reported in 41.6% of patients; it was associated with the female sex ( P =0.032), need for revision surgery ( P =0.019), and greater lateral displacement of the apical lumbar vertebrae ( P =0.028). The association between preoperative and postoperative pain trended toward significance ( P =0.07). At 6 months postoperatively, 91.8% had pain resolution; the same number remained pain-free at the time of last follow-up. The presence of a postoperative complication was associated with new-onset postoperative pain that resolved ( P =0.009). Only 8.2% had persistent pain, although no risk factors were found to be associated with persistent pain. In our cohort of 279 patients with a minimum 2-year follow-up after AVBT, 68.1% reported preoperative pain. Nearly 42% reported postoperative pain at any time point, but only 8.2% had persistent pain. Postoperative pain after AVBT was associated with female sex, revision surgery, and Lenke lumbar modifier. AVBT is associated with a significant reduction in pain, and few patients report long-term postoperative pain.

A novel risk calculator predicting surgical site infection after spinal surgery in patients with cerebral palsy.

To develop and validate a risk calculator based on preoperative factors to predict the probability of surgical site infection (SSI) in patients with cerebral palsy (CP) undergoing spinal surgery. This was a multicenter retrospective cohort study of pediatric patients with CP who underwent spinal fusion. In the development stage, preoperative known factors were collected, and a risk calculator was developed by comparing multiple models and choosing the model with the highest discrimination and calibration abilities. This model was then tested with a separate population in the validation stage. Among the 255 patients in the development stage, risk of SSI was 11%. A final prediction model included non-ambulatory status (odds ratio [OR] 4.0), diaper dependence (OR 2.5), age younger than 12years (OR 2.5), major coronal curve magnitude greater than 90° (OR 1.3), behavioral disorder/delay (OR 1.3), and revision surgery (OR 1.3) as risk factors. This model had a predictive ability of 73.4% for SSI, along with excellent calibration ability (p=0.878). Among the 390 patients in the validation stage, risk of SSI was 8.2%. The discrimination of the model in the validation phase was 0.743 and calibration was p=0.435, indicating 74.3% predictive ability and no difference between predicted and observed values. This study provides a risk calculator to identify the risk of SSI after spine surgery for patients with CP. This will allow us to enhance decision-making and patient care while providing valid hospital comparisons, public reporting mechanisms, and reimbursement determinations.

Early outcomes of growth friendly instrumentation in children with Williams syndrome.

Although scoliosis and kyphosis have been associated with Williams Syndrome (WS), no previous literature has reported on surgical treatment for early onset scoliosis (EOS) in WS. The aim of this case series is to report on the outcomes of spine deformity surgery in patients with EOS and WS and any perioperative anesthetic or cardiovascular complications. One multicenter database was queried for all patients with WS who underwent growth-friendly (GF) treatment before age 12 between 2000 and 2017. Demographics, surgical, and growth-friendly data were queried. Radiographs were measured for curve magnitude, T1-T12 length, and T1-S1 length. Seven patients were analyzed (3 males, 4 females). Patients were at a median age of 2.8years at initial surgery with median follow-up 3.6years (range 2.0-12years) after index surgery. The initial surgical treatments were as follows: 2 traditional growing rods (TGR), 2 magnetically controlled growing rods (MCGR), and 3 vertical expandable prosthetic titanium ribs (VEPTR). The median duration of growth-friendly treatment was 5.0years (range, 2.6-10.4years) with a median number of 9 device lengthenings. The median improvement in coronal curve magnitude from preoperative to most recent follow-up was 19° (range, 54°-9°). Three patients have completed GF treatment: one underwent definitive fusion, and two are under observation with apparent spontaneous fusion and retain the original GF implants. No peri-operative anesthetic or cardiovascular complications occurred. Few studies have reported on surgical outcomes in WS patients with EOS. In this case series, 6/7 patients experienced curve improvement with growth-friendly spine instrumentation. This study suggests that growth-friendly instrumentation for severe EOS in WS can be used for control of spinal deformity while allowing for further growth. Associated complications were typical of distraction-based EOS surgical treatment. There were 62 total procedures with general anesthesia, but no perioperative cardiac complications occurred.

Growth-Friendly Spine Surgery in Arthrogryposis Multiplex Congenita.

Arthrogryposis multiplex congenita (AMC) is a condition that describes neonates born with ≥2 distinct congenital contractures. Despite spinal deformity in 3% to 69% of patients, inadequate data exist on growth-friendly instrumentation (GFI) in AMC. Our study objectives were to describe current GFI trends in children with AMC and early-onset scoliosis (EOS) and to compare long-term outcomes with a matched idiopathic EOS (IEOS) cohort to determine whether spinal rigidity or extremity contractures influenced outcomes. Children with AMC and spinal deformity of ≥30° who were treated with GFI for ≥24 months were identified from a multicenter EOS database (1993 to 2017). Propensity scoring matched 35 patients with AMC to 112 patients with IEOS with regard to age, sex, construct, and curve. Multivariable linear mixed modeling compared changes in spinal deformity and the 24-item Early Onset Scoliosis Questionnaire (EOSQ-24) across cohorts. Cohort complications and reoperations were analyzed using multivariable Poisson regression. Preoperatively, groups did not differ with regard to age (p = 0.87), sex (p = 0.96), construct (p = 0.62), rate of nonoperative treatment (p = 0.54), and major coronal curve magnitude (p = 0.96). After the index GFI, patients with AMC had reduced percentage of coronal correction (35% compared with 44%; p = 0.01), larger residual coronal curves (49° compared with 42°; p = 0.03), and comparable percentage of kyphosis correction (17% compared with 21%; p = 0.52). In GFI graduates (n = 81), final coronal curve magnitude (55° compared with 43°; p = 0.22) and final sagittal curve magnitude (47° compared with 47°; p = 0.45) were not significantly different at the latest follow-up after definitive surgery. The patients with AMC had reduced T1-S1 length (p < 0.001), comparable T1-S1 growth velocity (0.66 compared with 0.85 mm/month; p = 0.05), and poorer EOSQ-24 scores at the time of the latest follow-up (64 compared with 83 points; p < 0.001). After adjusting for ambulatory status and GFI duration, patients with AMC developed 51% more complications (incidence rate ratio, 1.51 [95% confidence interval (CI), 1.11 to 2.04]; p = 0.009) and 0.2 more complications/year (95% CI, 0.02 to 0.33 more; p = 0.03) compared with patients with IEOS. Patients with AMC and EOS experienced less initial deformity correction after the index surgical procedure, but final GFI curve magnitudes and total T1-S1 growth during active treatment were statistically and clinically comparable with IEOS. Nonambulatory patients with AMC with longer GFI treatment durations developed the most complications. Multidisciplinary perioperative management is necessary to optimize GFI and to improve quality of life in this complex population. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Determining the association between the radiographic parameters and the SRS-22 scores in Chinese female patients with adolescent idiopathic scoliosis: does curve pattern matter?

Background: The Scoliosis Research Society (SRS)-22 outcomes have been shown to be correlated with radiographic parameter of adolescent idiopathic scoliosis (AIS). A recent study suggested that curve patterns might play a role in assessing the influence of deformity on patient’s reported outcomes. The aim of this study was to examine the relationship between radiographic parameters and SRS-22 questionnaire outcomes in female patients with adolescent AIS among the Chinese population based on five curve patterns. Patients and Methods: The radiographic data and SRS-22 questionnaires of 259 female AIS patients were reviewed. Radiographic measurements included: Cobb angle of the major curve, T1 tilt angle, apical vertebral rotation, apical vertebral translation (AVT), thoracic kyphosis, and lumbar lordosis. Curve patterns included single thoracic (T), single thoracolumbar/lumbar (TL), double thoracic (DT), double major (DM), and triple major (TM). The correlation between radiographic measurements and each domain in SRS-22 was determined by Pearson’s correlation coefficient. Results: The curve magnitude and AVT of the major curve were found to be significantly correlated with the self-image domain in all cases (Cobb angle: r = –0.426, p = 0.002; AVT: r = –0.281, p=0.006) and in all curve patterns except for TM. Compared to other groups, the TM group had a significantly larger major curve than the DT group and TL group (p ≤ 0.004). In TM group, the self-image scores were lower than TL group (p =0.018), and the function scores were lower than that in T, TL (p < 0.001) and DM groups (p =0.013). In the DT group, the T1 tilt was significantly correlated with the self-image domain (r = –0.376, p =0.004). In the T group, coronal curve magnitude was significantly correlated with function domain (r = −0.397, p < 0.001). Conclusion: Our findings suggested curve patterns should be considered in evaluating the correlations between radiographic parameters and SRS-22 outcomes in patients with AIS.

Comparison of different strategies on three-dimensional correction of AIS: which plane will suffer?

PurposeThere are distinct differences in strategy amongst experienced surgeons from different ‘scoliosis schools’ around the world. This study aims to test the hypothesis that, due to the 3-D nature of AIS, different strategies can lead to different coronal, axial and sagittal curve correction.MethodsConsecutive patients who underwent posterior scoliosis surgery for primary thoracic AIS were compared between three major scoliosis centres (n = 193). Patients were treated according to the local surgical expertise: Two centres perform primarily an axial apical derotation manoeuvre (centre 1: high implant density, convex rod first, centre 2: low implant density, concave rod first), whereas centre 3 performs posteromedial apical translation without active derotation. Pre- and postoperative shape of the main thoracic curve was analyzed using coronal curve angle, apical rotation and sagittal alignment parameters (pelvic incidence and tilt, T1–T12, T4-T12 and T10-L2 regional kyphosis angles, C7 slope and the level of the inflection point). In addition, the proximal junctional angle at follow-up was compared.ResultsPre-operative coronal curve magnitudes were similar between the 3 cohorts and improved 75%, 70% and 59%, from pre- to postoperative, respectively (P < 0.001). The strategy of centres 1 and 2 leads to significantly more apical derotation. Despite similar postoperative T4-T12 kyphosis, the strategy in centre 1 led to more thoracolumbar lordosis and in centre 2 to a higher inflection point as compared to centre 3. Proximal junctional angle was higher in centres 1 and 2 (P < 0.001) at final follow-up.ConclusionCurve correction by derotation may lead to thoracolumbar lordosis and therefore higher risk for proximal junctional kyphosis. Focus on sagittal plane by posteromedial translation, however, results in more residual coronal and axial deformity.

The correlation between spinal and chest wall deformities and pulmonary function in Marfan syndrome.

PurposeScoliosis, chest wall deformities and pulmonary involvement are common features of Marfan syndrome (MFS). We aimed to assess the impact of spinal and chest wall deformities on pulmonary function in paediatric MFS patients with a surgically managed spinal deformity.MethodsIn this multicentre retrospective study, spirometry, lung volumes and radiographic imaging were performed on 26 MFS patients between the ages of seven and 18 years who were undergoing planned spinal fusion surgery for spinal deformity. A correlation analysis assessed the relationship between radiographic measurements of spinal and chest wall deformities and predicted total lung capacity (TLC), forced vital capacity (FVC) and the ratio between forced expiratory volume in one second and FVC (FEV1/FVC).ResultsIn total, 18 patients (70%) had impaired pulmonary function. Thoracic kyphosis (mean 19.3°; -32° to 54°) had a strong positive correlation with FEV1/FVC (r = 0.65; p < 0.001). Significant decrease in FEV1/FVC below 80% occurred at kyphosis under 15° (p = 0.004). Kyphosis had a moderate negative correlation with FVC (r = -0.43; p = 0.03). Chest wall deformity had a strong negative correlation with FEV1/FVC (r = -0.61; p = 0.001). The magnitude of the thoracic curve (mean 55.2°; 28° to 92°) had a significant moderate negative correlation with TLC (r = -0.45; p = 0.04).ConclusionIn MFS, three factors correlate with decreased pulmonary function measures: hypokyphosis, increasing chest wall deformity and increasing coronal curve magnitude. Hypokyphosis and increased chest wall deformity correlated with diminished FEV1/FVC; increasing thoracic spinal curvature with diminished TLC. Further analysis with a larger cohort will help better define the relationship between these deformities and pulmonary function in this unique population.Level of EvidenceIV

Axial plane characteristics of thoracic scoliosis and their usefulness for determining the fusion levels and the correction technique.

There is insufficient information regarding axial plane characteristics of scoliosis despite its 3D nature. The posterior-anterior vertebral vector (VV) has been proposed to characterize the axial plane appearances of the thoracic scoliosis. This study aimed to highlight the importance of knowledge of axial plane features when determining fusion levels and correction techniques of thoracic curves. Altogether, 233 thoracic curves were analyzed using the VV after proving its usability instead of 3D angles to determine axial plane parameters such as apical vertebral (APV) axial rotations, APV lateral displacement, and intervertebral rotations (IVR). K-means clustering and regression analysis were used to identify axial plane curve patterns and determine the relationship between the coronal angles and axial plane characteristics, respectively. A close correlation was found between 3D angles and VV projected angles. Eight axial plane clusters were distinct, exhibiting different lateral APV displacement toward the interacetabular axis with relatively small axial rotations and a simultaneous decrease in sagittal curves. The regression analysis showed that the correlation of coronal curve magnitude was significantly stronger (r = 0.78) with APV lateral translation than with APV axial rotation (r = 0.65). Based on these findings, the primary goal of scoliosis correction should focus on minimizing lateral translation rather than eliminating axial rotation. Knowing the IVR in the axial plane helps accurately determine the limits of the structural curves. VV-based axial views can facilitate the accurate determination of the end vertebrae and selection of the appropriate correction technique of the curve. These slides can be retrieved under Electronic Supplementary Material.

Referral indications and prevalence of sleep abnormalities in children with early onset scoliosis.

This study describes the utility of overnight sleep studies in children with early onset scoliosis (EOS). Children with EOS have diminished respiratory reserve which is associated with abnormal breathing and sleep quality in children. Currently, there are no criteria for referral of these children to evaluate breathing during sleep or data on the use of sleep treatments as part of their supportive care. A review of the 159 patients with EOS who were followed at a single institution from 2003 to 2016 identified 68 who underwent overnight polysomnograms (PSGs). Sixty-five of 68 (96%) had elevated apnea-hypopnea index (AHI) and a majority (56%) were prescribed nighttime respiratory support. A majority of young children (< 5years) with PSG were referred for a history of snoring, apnea, or restless sleep; all 30 had abnormal PSGs. Twenty-seven (90%) had nighttime hypoxemia (nadir oxygen saturation values < 92%). Eighteen (60%) were referred to otolaryngology, of whom 11 (37%) subsequently underwent tonsil and/or adenoid removal. In older children (≥ 5years), those referred for PSGs had more severe restrictive chest wall disease [lower forced vital capacity (FVC) values] than those who were not sent for PSG. Correlation between FVC and apnea-hypopnea index, however, was not significant. Pre-operative coronal curve magnitude did not strongly correlate with nadir SaO2 or AHI in either age group. These results suggest that sleep studies are underutilized in the management of children with EOS. Inadequate and poor-quality sleep adversely affects growth, behavior, and cognitive function in children. This study suggests that screening for sleep abnormalities should be incorporated into assessment and treatment of more patients with EOS.

A three-dimensional analysis of scoliosis progression in non-idiopathic scoliosis: is it similar to adolescent idiopathic scoliosis?

To evaluate the three-dimensional (3D) characteristics of spine deformity in patients with non-idiopathic scoliosis compared with those observed in patients with adolescent idiopathic scoliosis (AIS). A retrospective chart review was conducted to identify patients with non-idiopathic scoliosis. Twenty-eight patients with neural axis (NA) abnormalities (Chiari 1, syrinx) and 20 patients with connective tissue disorder (CTD) (Marfan's, Beal's, Ehlers-Danlos syndrome, mixed) were identified. The 3D parameters of the coronal, sagittal, and axial plane were compared with 284 AIS patients with a similar range of coronal deformity. The average coronal curve was similar between all three groups (AIS 48 ± 15°, CTD 43 ± 22°, and NA 49 ± 18°; p = 0.4). The NA patients had significantly greater 3D thoracic kyphosis (20 ± 18° vs 10 ± 15°, p = 0.001) and less thoracic apical vertebral rotation (- 5 ± 18° vs - 12 ± 10°, p = 0.003) when compared with AIS. The CTD group's 3D thoracic kyphosis (p = 0.7) and apical vertebral rotation (p = 0.09) did not significantly differ from AIS. Significant negative correlations were found in all three groups between thoracic kyphosis and coronal curve magnitude (AIS r = - 0.49, CTD r = - 0.772, NA r = -0.677, all p < 0.001). Scoliotic patients with NA abnormalities have a more kyphotic, less-rotated 3D profile than patients with AIS, while scoliosis patients with CTD have 3D features similar to AIS. Irrespective of the underlying diagnosis, however, greater scoliotic curves were associated with a greater loss of intersegmental kyphosis, suggesting a similar biomechanical pathophysiology for curve progression.

Anatomic Trajectory for Iliac Screw Placement in Pediatric Scoliosis and Spondylolisthesis: An Alternative to S2-Alar Iliac Portal

Study DesignSingle-center retrospective study. ObjectiveTo analyze two-year postoperative outcomes following spinopelvic fixation in pediatric patients using the anatomic trajectory (AT) portal for iliac screws. SummaryIliac fixation is crucial in situations requiring fusion to sacrum. Challenges include complex anatomy, pelvic deformation, severe deformity, and previous surgery. The PSIS portal requires significant dissection, rod connectors, and complex bends. The SAI portal requires navigating the screw across the SI joint to the ilium. The anatomic trajectory (AT), first reported in 2009, is between the PSIS and SAI portal, without prominence, connectors, or complex bends. MethodsFifty-four patients aged ≤18 years requiring instrumentation to the Ilium with minimum follow-up of two years (mean 44 months) were clinically and radiographically evaluated. Changes in coronal curve magnitude and pelvic obliquity were assessed using paired t test for patients with cerebral palsy. Spondylolisthesis reduction was assessed in patients with moderate- to high-grade spondylolisthesis (Meyerding grade 3 and 4). ResultsA total of 108 iliac screws were inserted using AT portal in 54 patients. Twenty-eight neuromuscular and syndromic patients had an initial mean coronal curve of 85° corrected to 23° at two years (p < .001) and a pelvic obliquity of 22° corrected to 4° (p < .001). Twenty patients with moderate- to high-grade spondylolisthesis treated with reduction and interbody fixation improved significantly with respect to their slip angles (7° ± 14.7° to −7.9° ± 6.1°, p = .003). In the neuromuscular group, two surgical site infections occurred, two had implant fractures, and 12 had asymptomatic iliac screw loosening, none requiring revision. In the spondylolisthesis group, there were no neurologic complications and one had prominent screw requiring removal. Of 108 iliac screws, 2 rod connectors were employed. ConclusionIliac screw insertion using the AT portal is a safe and effective method of pelvic fixation in pediatric patients with satisfactory radiographic correction and minimal complications. Level of EvidenceLevel 4.

Persistence and Progression of Airway Obstruction in Children With Early Onset Scoliosis.

Obstructive lung disease occurs in 30% of children with early onset scoliosis (EOS); changes in degree of airway obstruction over time have not been reported. Longitudinal patterns of incidental, persistent, and progressive airway obstruction were retrospectively analyzed in a cohort of children with EOS with at least 1 forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) value <85% on serial spirometric assessments over a ≥3-year observation period. The prevalence of clinical features and the severity of coronal and sagittal spine deformities for each group at the beginning and end of the study period were compared. Airway obstruction was incidental in 12 (24%) and persistent in 37 (76%) of 49 children with EOS. Twenty of 37 (54%) of those with persistent obstruction developed progressive airway obstruction. The decline in FEV1/FVC over 6±2 years was insignificant in the incidental group (4%±2%) and the persistent nonprogressive group (7%±4%) but significant in the progressive group (13%±4%, t test; P=0.002). In total, 29% of the 49 children at the onset and 57% at the end of the study had airway obstruction. The incidental, persistent nonprogressive, and progressive groups did not differ with regard to age, diagnosis distribution, or sex. The initial coronal curve size, apex, direction of the curve, and degree of kyphosis were statistically similar among the 3 groups. Coronal curve magnitude inversely correlated with FEV1/FVC at the end but not the beginning of the study (r=-0.19, P=0.002). Six of 19 responded to bronchodilator treatment, suggesting concurrent asthma. Airway obstruction did not relate to restrictive pulmonary abnormalities measured by FVC at first or last timepoints [slope=-0.076 (95% confidence interval, -0.99 to 0.038; P=0.19)]. Changes in degrees of airway obstruction and restrictive lung disease over time did not correlate [slope=-0.125 (95% confidence interval, -0.294 to 0.044; P=0.14)]. Children with EOS and progressive airway obstruction represent an important subgroup which may require new surgical and nonsurgical treatment strategies to prevent loss of lung function over time.

Improvement in Scoliosis Research Society-22R Pain Scores After Surgery for Adolescent Idiopathic Scoliosis.

Longitudinal cohort. To investigate whether patients with painful adolescent idiopathic scoliosis experience pain relief with surgical treatment. Adolescent idiopathic scoliosis (AIS) was previously thought to be a painless condition, but recent studies have shown that a significant proportion of patients have pain. Little information is available regarding pain relief with surgical treatment for AIS. Patients enrolled in a prospective database of surgically treated AIS were divided into two groups based on their preoperative Scoliosis Research Society (SRS)-22R pain domain score. Patients with a preoperative pain domain score of 4 or more (N = 1005) were classified as nonpainful. If the preoperative pain domain score was less than 4 (N = 505), they were classified as painful. Demographics, SRS total and domain scores, and changes with treatment were compared for the two groups. The two groups had similar demographics and preoperative coronal curve magnitude. Patients with painful scoliosis experienced significant improvement in SRS-22R pain scores, from 3.29 preoperatively to 4.03 postoperatively (P < 0.000). Eighty-one percent of these patients reached the minimum clinically important difference threshold (0.20) for improvement in pain score. Painful scoliosis patients also had greater 2-year improvement in total and all domain scores than the nonpainful scoliosis patients (P < 0.000). Absolute values of SRS-22R total and domain scores were all greater at 2 years in the nonpainful group than the painful group. Patients with AIS with substantial back pain can be cautiously counseled to expect significant improvement in pain level with surgical correction of their deformity, even if curve progression is the primary indication for surgery. Although these patients achieve greater improvements in health-related quality of life compared with patients with mild or no pain, 2-year SRS-22R scores were still better in patients with mild or no pain preoperatively. 2.

Three column osteotomy for adult spine deformity: comparison of outcomes and complications between kyphosis and kyphoscoliosis

Background: To compare the surgical outcomes and complications between kyphosis and kyphoscoliosis when using three-column osteotomies.Methods: Adult spine deformity (ASD) patients with three column osteotomies from March 2005 to December 2014 in our center were retrospectively reviewed. Pre- and postoperative standing postero-anterior and lateral radiographs of the entire spine were obtained. Scoliosis Research Society-22 questionnaire [SRS-22] and Oswestry Disability Index [ODI] were administered preoperatively, postoperatively (surveys within 2 months after surgery), and at final follow-up. Patients were assigned to one of two groups according to pre-operative coronal curve magnitude: (1) if coronal curve <10°, patients were assigned to kyphosis group (K group); (2) if coronal curve >40°, patients were assigned to kyphoscoliosis group (S group).Results: 33 ASD patients were assigned to the kyphosis group (K group), of which 26 received PSO (pedicle subtraction osteotomy) and 7 VCR (vertebral column resection). 76 patients were assigned to kyphoscoliosis group (S group), of which 50 received PSO and 26 VCR. Patients in the K group were significantly older than in the S group (42.8 vs. 33.7 years, p < .05). Significantly longer OT (operation time) and more EBL (estimated blood loss) were observed in the S group as compared to K group (OT: 282 vs. 205 min, p < .05; EBL: 1827 vs. 1214ml, p < .05). No significant difference was noted for number of fusion levels between the groups (12.4 vs. 12.7, p > .05). Pre-operative radiographic parameters demonstrated no difference of GK (global kyphosis) and SVA (sagittal vertical axis) between the two groups (GK: 74.7° vs 76.2°, p > .05; SVA:53.2 vs. 55.7mm, p > .05). K group had larger KF than S group (26% vs. 15%, p < .05). Overall complication rate was higher in S group than in K group (30.3% vs. 18.2%, p < .05). No difference of neurological complication rates between the two groups (9.1% vs. 10.5%, p > .05).Conclusions: Kyphoscoliosis group had less KF, GK correction and more OT, EBL and surgical complications when receiving three column osteotomies.

Long-term outcomes of transforaminal lumbar interbody fusion in patients with spinal stenosis and degenerative scoliosis

Background ContextPatients with spinal deformity may present with complaints related to either the deformity itself or the manifestations of the coexisting spinal stenosis. There are reports of successful management of lumbar pathology in the absence of global sagittal or coronal imbalance, with limited decompression and fusion, addressing only the symptomatic segment. PurposeOur study examined the long-term outcomes of transforaminal lumbar interbody fusion (TLIF), a less extensive procedure, based on the experience of the senior author over the past 10 years. Study Design/SettingThis was a retrospective study of symptomatic lumbar spinal stenosis and spinal deformity managed by one surgeon at The Cleveland Clinic since 2003. Patient SampleForty-one patients were included in the study. Outcome MeasuresThe present study measures the long-term clinical functional outcomes of these patients through EQ-5D (EuroQol five dimensions questionnaire), PHQ-9 (Patient Health Questionnaire), and PDQ (Pain Disability Questionnaire) forms, along with documented radiographic parameters and Charlson Comorbidity Index (CCI). MethodsThere were no funding or potential conflicts of interest associated biases in the present study. Patients with symptomatic lumbar spinal stenosis with neutral global alignment in the sagittal and coronal planes and symptomatic stenosis at the deformity level were treated by limited fusion and TLIF, and had a follow-up period of at least 5 years. Excluded were patients under 18 years of age, had more than three levels of fusion, and had an active spinal malignancy or recent spinal trauma. The grouping variables were curve magnitude, revision surgeries, and TLIF levels. Clinical outcomes were compared in all the grouping variables. Analysis of variance (ANOVA) and chi-square tests were utilized; p<.05 was considered statistically significant. ResultsThe average age and follow-up period were 66±10 and 7.5 years, respectively. There was no statistical difference between patients with curves measuring between 10° and 20° and greater than 20° for EQ-5D, PHQ-9, and PDQ. Patients had worse PDQ data with larger curves compared with smaller curves at both 5 years and final follow-up. Although there was no statistical significance between preoperative coronal curve magnitude and revision surgeries, patients with curves greater than 20° had higher rates of revision surgeries (75%; p=.343) in the global lumbar curve deformity group. Although there was no statistical significance for patients who underwent revision surgeries,those patients had low PHQ-9 values at the final follow-up (p=.09). The revision surgery rate was 48% in one-level TLIF and 18% in two-level TLIF. Moderate pain disability scores were noticed for one-level TLIF patients (mean=75) compared with two-level TLIF patients (mean=27) at the final follow-up, and approached statistical significance in this comparison (p=.06). ConclusionAlthough this topic has a limited audience to spinal deformity surgeons, the prevalence of patients who present with adult spinal deformities has been increasing. Short segment fusion, in the setting of modest spinal deformity, is a reasonable and safe option. Further study on the concept of short segment fusions in the growing patient population is required as more comprehensive fusions do have noted complication rates, and a compromise must be reached between the extent of surgery that is enough to provide pain relief and disability and the degree of surgery that is too much to be tolerated in terms of complication rates.