Correction Of Main Thoracic Curve Research Articles

Does levelling of T1 tilt intra-operatively affect post-operative shoulder balancein adolescent idiopathic scoliosis patients?

Previous studies have shown that T1 tilt is positively correlated with post-operative shoulder balance (SB). The aim of this study was to explore the role of intra-operative T1 tilt, among other shoulder parameters as a potential parameter to predict post-operative SB in adolescent idiopathic scoliosis (AIS) patients. A retrospective review of AIS patients with structural thoracic curves with minimum 2year follow up was conducted from a single tertiary center. Standing pre-operative, 1st erect, 1year and 2-year follow-up; and intra-operative final prone radiographs were reviewed along with clinical data. Patients were stratified into 2 cohorts: Group A-Final intra-operative T1 tilt ≤5° and Group B-Final intra-operative T1 tilt >5°. These groups were compared for post-operative SB as a whole and separately for patients with baseline right or left shoulder high and if UIV was T2 or T3/T4. Patients with optimal SB (Radiographic shoulder height (RSH) <2cm) at 2years were compared to sub-optimal SB (RSH ≥ 2cm) with respect to multiple SB variables. 55 patients (mean age 15.1years-old, 43 F, mean BMI 22, mean thoracic Cobb-49.8°) were included. Based on Lenke curve types, there were 13 patients with type 1A, 10 patients with 1B, 12 patients with 1C, 7 patients with 2A, 4 patients with 2B and 9 patients with type 3C. T1 tilt was significantly correlated with RSH, Clavicle angle difference (CAD), First Rib Angle (FRA), and UIV tilt at first erect, 1-year, and 2-year post-op radiographs (p < 0.05 for all). When comparing groups, A and B, Group A patients showed significantly better restoration of their 2-year SB parameters; RSH (6.8 vs 11.8mm, p = 0.01), CAD (3.9 vs 9.1 p < 0.001) and T1 tilt (4.7 vs 7.8° p = 0.01). Similar results were found for patients with baseline right shoulder high; RSH (p = 0.04), CAD (p < 0.001) and T1 tilt (p < 0.001) and whether UIV was T2 or T3/T4. Eight patients with sub-optimal SB had worse intra-operative T1 tilt (p = 0.03) compared to 47 patients with optimal SB despite no difference in MT Cobb correction (83.1 vs 79.8%, p = 0.57). Post-operative T1 tilt correlates with lateral shoulder parameters at first erect, 1year, and 2-year radiographs. Therefore, T1 tilt can potentially be used as a surrogate to predict post-operative SB. Leveling intra-operative T1 tilt ≤5° is associated with better 2-year post-operative shoulder balance parameters irrespective of whether the UIV was T2 or T3/T4. Patients with sub-optimal SB at 2years had worse final intra-operative T1 tilt despite similar percent correction of main thoracic curve for all patients.

Does Sacral Slanting Affect Postoperative Shoulder Balance in Patients With Lenke Type 2A Adolescent Idiopathic Scoliosis?

Even minor sacral slanting can influence T1 tilt and shoulder balance. Yet, the relationship between sacral slanting and postoperative shoulder imbalance (PSI) has not been previously explored. To determine risk factors for PSI in Lenke 2A adolescent idiopathic scoliosis (AIS) patients, with an emphasis on sacral slanting. The study encompassed 96 consecutive patients who had undergone posterior correction and fusion surgery for Lenke type 2A AIS. Patients were grouped into PSI(+) and PSI(-) based on postoperative outcomes. Additionally, they were classified into left-sided slanting, no slanting, and right-sided slanting groups according to the degree of sacral slanting. Various radiological measures were compared. Patients in the PSI(+) group exhibited a smaller preoperative proximal thoracic curve and a higher main thoracic curve correction rate than those in the PSI(-) group. The presence or absence of sacral slanting did not exhibit a significant variation in PSI occurrence. However, the right-sided sacral slanting group showed a larger delta radiologic shoulder height compared to the other 2 groups (7.1 mm vs. 1.5 & 3.3 mm). Sacral slanting was not directly linked to the development of PSI. Despite the common postoperative elevation of the left shoulder, the shoulder height differences decreased over the follow-up period. Especially in cases with a right-sided tilted sacrum, the PSI demonstrated progressive improvement, with an associated increase in the rightward distal wedging angle, leading to distal adding-on.

Isolated main thoracic curve fusion in idiopathic scoliosis: optimizing radiographic outcomes using lumbar modifiers to guide correction.

Does differential correction of main thoracic curve (MTC) and instrumented LIV angulation based on lumbar modifiers affect radiographic outcomes, and can preoperative supine AP radiograph be used to guide correction for optimal final radiographic alignment. Retrospective analysis of idiopathic scoliosis patients who underwent selective thoracic fusions (LIV T11-L1) for Lenke 1 and 2 curve patterns, < 18years of age. 2-year minimum follow-up. Optimal outcome meant LIV + 1 of < 5 degrees disk-wedging and C7-CSVL < 2cm. 82 patients met inclusion criteria (70% female), mean age 14.1years. 24 patients were A modifier, 21 B modifier, and 37 C modifier. There were 52 optimal and 30 suboptimal outcomes. LIV was not associated with outcome (p = 0.08). For optimal outcomes, A modifiers' MTC improved 65%, B modifiers 65%, and C modifiers 59%. C modifiers' MTC correction was less than A modifiers (p = 0.03) but equivalent to B modifiers' (p = 0.10). A modifiers' LIV + 1 tilt improved 65%, B modifiers 64%, and C modifiers 56%. C modifiers' instrumented LIV angulation was greater than A modifiers' (p < 0.01) but equivalent to B modifiers' (p = 0.06). Preoperative supine LIV + 1 tilt was 16o in optimal outcomes and 15° in suboptimal outcomes. Instrumented LIV angulation was 9° for both. The correction between preoperative LIV + 1 tilt and instrumented LIV angulation was not significantly different between groups (p = 0.67). Differential MTC and LIV tilt correction based on lumbar modifier may be a valid goal. Optimizing radiographic outcome by matching instrumented LIV angulation to preoperative supine LIV + 1 tilt could not be proven. IV.

Preoperative Less Right Shoulder Elevation Had a Higher Risk of Postoperative Shoulder Imbalance When Main Thoracic Curve Shows Higher Correction Regardless of the Upper Instrumented Vertebra Level for Patients with Adolescent Idiopathic Scoliosis Lenke Type 1.

This is a retrospective study. This study aimed to investigate the incidence of and risk factors for postoperative shoulder imbalance (PSI) in patients with Lenke type 1. PSI is a complication resulting in poor self-image and satisfaction in adolescent idiopathic scoliosis (AIS) patients. We examined the data of AIS patients with Lenke type 1 curves who underwent posterior fusion surgery in a retrospective manner. PSI was defined as a 2-year postoperative absolute radiographic shoulder height (RSH) of ≥2 cm. Patients were divided into two groups based on the presence of PSI and the level of their upper instrumented vertebra (UIV) (UIV at T2 or T3 [U-UIV] or UIV below T3 [L-UIV]). The radiographic parameters and clinical outcomes were compared, and the cutoff values of risk factors were identified by multivariate analysis. Of 104 patients, 21 (20.2%) had left shoulder elevation PSI. The PSI group had a significantly greater preoperative RSH (-5.1 mm vs. -14.3 mm) and main thoracic (MT) curve correction rate (77.3% vs. 69.1%) than the non-PSI group. The PSI incidence did not differ between the U-UIV and L-UIV groups. Multivariate analysis identified preoperative RSH and the MT curve correction rate as independent risk factors for PSI. The receiver operating characteristic curve analysis identified the preoperative RSH cutoff value as -6.5 mm and MT curve correction rate cutoff value as 76.9%. Even in AIS patients with Lenke type 1 curves, the incidence of PSI was relatively high (20.2%). Patients with preoperative lower right shoulder elevation (i.e., RSH >-6.5 mm) had a higher risk of PSI regardless of UIV level when the MT curve showed a higher correction rate (i.e., correction rate >76.9%).

Postoperative shoulder balance in Lenke type 1 adolescent idiopathic scoliosis patients with large thoracic curve (Cobb angle ≥ 70 degrees): a radiographic study

BackgroundLarge amounts of thoracic curve correction had been considered as a risk factor for postoperative shoulder imbalance (PSI) in adolescent idiopathic scoliosis (AIS) patients. This study aims to evaluate postoperative shoulder balance in Lenke type 1 AIS patients with large thoracic curve (Cobb angle ≥ 70 degrees) and compared it with those with moderate thoracic curve (Cobb angle < 70 degrees).MethodsA total of 47 Lenke type 1 AIS patients underwent posterior correction surgery between Sept. 2016 to Nov. 2018 in our institution were included. All these patient were divided into 2 groups based on the severity of main thoracic (MT) curve. Group A consisted of 25 cases with MT curve equal to or more than 70 degree while Group B consisted of 22 cases with MT curve less than 70 degree. Proximal thoracic (PT) Cobb angle, MT Cobb angle, MT apical vertebral translation (AVT), T2-T5 kyphosis, T5-T12 kyphosis, and radiographic shoulder height (RSH) were compared between these 2 groups preoperatively, immediately after surgery, and at a minimum of two-year follow-up.ResultsAlthough all the correction of PT Cobb angle (15.8° ± 6.0° vs 12.5° ± 3.6°, P = 0.028), that of MT Cobb angle 47.3° ± 9.1° vs 30.9° ± 6.7°, P < 0.001) and that of MT AVT (35.1 mm ± 16.0 mm vs 24.1 mm ± 8.9 mm, P = 0.007) were significantly larger in Group A when compared with Group B, RSH was comparable between these 2 groups at last follow up (7.5 mm ± 7.4 mm vs 9.2 mm ± 4.2 mm P = 0.363). Most of the patients gained satisfactory shoulder balance with only 7 cases with minimal PSI in group A (28%) and only 6 cases with minimal PSI in group B (27.3%) at last follow-up (P > 0.05).ConclusionsAlthough Lenke type 1 AIS patients with large thoracic curve had more amounts of MT curve correction when compared with those with moderate thoracic curve, it did not lead to higher incidence of PSI if the correction rate is proper.

Rod Link Reducer system in adolescent idiopathic scoliosis: a retrospective observational trial.

The Rod Link Reducer (RLR) (Globus Medical, PA, USA) allows direct three-dimensional correction of the spine deformity follows the direct vertebral rotation (DVR) theories. The purpose of this retrospective study is to compare RLR with traditional correction technique (TCT) in two cohorts of patients with adolescent idiopathic scoliosis (AIS). Fifty-four patients (M:F = 1:8) between 2018 and 2020 were included. The first group (n = 22) was treated by RLR while the second one (n = 32) by TCT. All spines were classified as per the Lenke system. Length of hospitalization, days in intensive care unit (ICU), operative time, and blood loss were recorded. SRS-30 and SF-36 questionnaires were administered pre-operative and post-operative. We collected radiological data: pre-operative and post-operative Cobb angles, coronal and sagittal balance, trunk and thoracic height. RLR and TCT groups are homogeneous in age (p = 0.317), sex ratio (p = 0.347), and Risser stage (p = 0.222). Between both groups there was no significant statistical difference in haemoglobin value, hospitalization length, days in ICU, operative times, SF-36, SRS-30, NRS, and perceived satisfaction. RLR group shows a better improvement of correction of main thoracic (MT) curve (RLR 54.2% ± 15.9%/TCT 38.1% ± 20.4%, p = 0.031). Nevertheless, RLR group shows a worse thoracic kyphosis correction (RLR 16.82° ± 9.13°/27.12° ± 12.13°, p = 0.015). RLR system allows a more effective MT curve correction than TCT systems, but it seems to give a hypokyphosis effect.

What happens to the unfused upper thoracic curve after posterior spinal fusion for adolescent idiopathic scoliosis?

Spontaneous lumbar curve correction after selective thoracic fusion in surgery for adolescent idiopathic scoliosis (AIS) is well described. However, only a few articles have described the course of the uninstrumented upper thoracic (UT) curve after fusion, and the majority involve a hybrid construct. In this study, the authors sought to determine the outcomes and associated factors of uninstrumented UT curves in patients with AIS. The authors retrospectively reviewed a prospectively collected multicenter AIS registry for all consecutive patients with Lenke type 1-4 curves with a 2-year minimum follow-up. UT curves were considered uninstrumented if the upper instrumented vertebra (UIV) did not extend above 1 level from the lower end vertebra of the UT curve. The authors defined progression as > 5°, and divided patients into two cohorts: those with improvement in the UT curve (IMP) and those without improvement in the UT curve (NO IMP). Radiographic, demographic, and Scoliosis Research Society (SRS)-22 survey outcome measures were compared using univariate analysis, and significant factors were compared using a multivariate regression model. The study included 450 patients (370 females and 80 males). The UT curve self-corrected in 86% of patients (n = 385), there was no change in 14% (n = 65), and no patients worsened. Preoperatively, patients were similar with respect to Lenke classification (p = 0.44), age (p = 0.31), sex (p = 0.85), and Risser score (p = 0.14). The UT curves in the IMP group self-corrected from 24.7° ± 6.5° to 12.6° ± 5.9°, whereas in the NO IMP group UT curves remained the same, from 20.3° ± 5.8° to 18.5° ± 5.7°. In a multivariate analysis, preoperative main thoracic (MT) curve size (p = 0.004) and MT curve correction (p = 0.001) remained significant predictors of UT curve improvement. Greater correction of the MT curve and larger initial MT curve size were associated with greater likelihood of UT curve improvement. Spontaneous UT curve correction occurred in the majority (86%) of unfused UT curves after MT curve correction in Lenke 1-4 curve types. The magnitude of preoperative MT curve size and postoperative MT curve correction were independent predictors of spontaneous UT curve correction.

Clinical, radiological and HRQoL outcomes after selective thoracic fusion with minimum 15-year follow-up.

The purpose of the study was to provide a 15-year natural history evaluation of the radiographic appearance of uninstrumented compensatory lumbar curves in patients who had undergone selective thoracic fusion (STF) for scoliosis, measure any changes in health-related quality of life scores (HRQoL) and compare them with controls matched for age, gender and body-mass index (BMI). STF group included 43 female adolescent idiopathic scoliosis (AIS) patients who underwent STF with mean age 33(27-42) years and a mean follow-up of 18.7 (15-28) years, mean BMI 22(18-29). Preop, early postop and follow-up radiographs were reviewed for behavior of lumbar curves. Control group included a random selection of healthy volunteers with no history of back pain and with mean age 33(27-41), and mean BMI 22(17-33). HRQoL scores were compared between two groups in latest f/up. Radiographs including low dose biplanar imaging with EOS were used to measure disc heights and assess for radiographic evidence of degenerative changes. Various parameters were statistically compared. Posterior fusion was performed in all 43, with all pedicle screws used in 41 and all-hook constructs in 2. Main thoracic curve correction was improved from pre-op to early-post-op and maintained at latest f/up (55.6°-16.1°-16.9°). Spontaneous lumbar curve correction (SLCC) was also maintained beyond 15years (39.9°-16.6°-17.1°). Two patients developed coronal decompensation following surgery, but improved with time and were well compensated at final follow-up. Mean HRQoL scores, self-image and mental health scores were higher in STF group than control group (p < 0.05). SRS-22r pain and function, Oswestry Disability Index and Numeric Rating Scale, marital status, number of children were similar between the groups(p > 0.05). All disc heights except L5-S1 were significantly lower in STF group (p < 0.05). There was no significant difference between the groups for degenerative changes in the latest radiographs. In this group of patients, the uninstrumented lumbar curve spontaneously corrected and the correction was maintained after 18years following surgery using STF. Mild degenerative changes were seen radiographically and HRQoL scores suggest that the psychological-functional well-being are quite good in the long term in AIS patients who have undergone STF when compared with an age-gender-BMI-matched population.

Selection of the lowest instrumented vertebra in main thoracic adolescent idiopathic scoliosis: Is it safe to fuse shorter than the last touched vertebra?

Fusing shorter than the last touched vertebra (LTV) is a safe approach in flexible main thoracic (MT) adolescent idiopathic scoliosis (AIS) curves. This was a prospective study on consecutive AIS patients surgically treated with selective fusion of the MT curve. Fusion-level selection was based on the fulcrum-bending radiograph method. Patients were grouped based on the position of the lowest instrumented vertebra as proximal to the LTV (proxLTV, n = 43), at the LTV (atLTV, n = 45), and distal to the LTV (distLTV, n = 21). A total of 109 patients were included in the study. Preoperatively, the distLTV group had greater lumbar Cobb angle, lumbar apical translation, and less flexibility in the MT curve. At 2-year follow-up, the groups did not differ in MT curve correction, but the distLTV had larger lumbar Cobb angle, more apical translation, and worse coronal balance. Distal adding-on was observed in 11 patients (26%) in the proxLTV group, four patients (9%) in the atLTV group, and one patient (5%) in the distLTV group (p = 0.031). Adding-on was associated with younger patients and lower Risser grade at the time of surgery but not with any other radiographic parameter. No differences in SRS-22r scores were observed between the groups. Proximal fusion carries the risk of adding-on, but leaving unfused segments in the lower spine increases the potential for compensatory mechanisms to improve spinal and truncal balance. In mature patients with a flexible MT curve, surgeons may consider fusion at or cranial to the LTV.

Effectiveness analysis of Lenke type 1 adolescent idiopathic scoliosis with different proximal fixation vertebra

To investigate the short-term effectiveness of proximal fixation of one vertebra above to the upper end vertebra and the upper end vertebra in the treatment of Lenke type 1 adolescent idiopathic scoliosis (AIS) patients with preoperative right higher shoulder. The clinical data of 37 Lenke type 1 AIS patients treated with posterior correction between January 2010 and December 2015 were retrospectively analysed. According to proximal fixation vertebra, the patients were divided into 2 groups: group A ( n=17), proximal fixation of one vertebra above to the upper end vertebra; group B ( n=20), proximal fixation of the upper end vertebra. There was no significant difference in gender, age, Risser stage, radiographic shoulder height (RSH), flexibility of proximal thoracic curve, flexibility of main thoracic curve, flexibility of thoracolumbar/lumbar curve between 2 groups ( P>0.05). The main thoracic curve Cobb angle, proximal thoracic curve Cobb angle, thoracolumbar/lumbar curve Cobb angle, apical vertebral translation (AVT), clavicle angle (CA), RSH, coronal trunk shift, sagittal trunk shift, thoracic kyphosis (TK), and lumbar lordosis (LL) were measured by X-ray film before operation, and at 1 month, 1 year, and 2 years after operation. The correction indexes of main thoracic curve were evaluated, including the correction degree and correction rate of main thoracic curve and AVT correction at 1 month after operation, the loss degree and the loss rate of the correction of main thoracic curve at 2 years after operation. The operation time and intraoperation blood loss in group A were significantly greater than those in group B ( P<0.05). All the patients were followed up, and the follow-up time was 2-4 years (mean, 2.8 years) in group A and 2-3.5 years (mean, 2.6 years) in group B. No serious complication such as nerve damage occurred during perioperative period and follow-up period. No complication such as failure of fusion, loosening and rupture of internal fixator, adjacent segment degeneration, and proximal junctional kyphosis occurred. There was no significant difference between 2 groups in the correction degree and correction rate of main thoracic curve and AVT correction at 1 month after operation, the loss degree and the loss rate of the correction of main thoracic curve at 2 years after operation ( P>0.05). Comparison within the two groups: except for LL had no significant difference between pre- and post-operation ( P>0.05), the other indicators were significantly improved after operation ( P<0.05) in the two groups. There were significant differences in RSH, CA, proximal thoracic curve Cobb angle, and thoracolumbar/lumbar curve Cobb angle at each time point after operation ( P<0.05), and there were spontaneous correction during follow-up; however, there was no significant difference in main thoracic curve Cobb angle, AVT, TK, LL, trunk shift at each time point after operation ( P>0.05), and there was no significant loss during follow-up. Comparison between the two groups: there was no significant difference in all the radiographic indexes at pre- and post-operation ( P>0.05). For Lenke type 1 AIS patients with preoperative right high shoulder, proximal fixation vertebra be fixed to the upper end vertebral can obtain satisfactory short-term orthopedic effectiveness and reduce blood loss and operation time.

Postoperative translation of the upper instrumented vertebra in thoracic adolescent idiopathic scoliosis.

OBJECTIVEThe aim of this retrospective study was to analyze the influence of upper instrumented vertebra (UIV) translation from the C7 plumb line (C7PL) on the long-term postoperative results of patients with main thoracic (MT) adolescent idiopathic scoliosis (AIS).METHODSTwenty-five patients had been treated surgically for AIS with a Lenke type 1 curve and had been followed up for a mean period of 18.2 years. Radiographic parameters, pulmonary function measurements, and clinical outcomes were compared between the patients (n = 15) with UIV translation < 20 mm and those (n = 10) with UIV translation ≥ 20 mm at the final follow-up. Correlations between UIV translation and radiographic or pulmonary function parameters were analyzed.RESULTSPatients with ≥ 20 mm UIV translation at the final follow-up had a significantly larger preoperative UIV translation than that in the patients with < 20 mm UIV translation at follow-up. The former group also had a significantly lower correction rate of the MT curve, higher chest cage ratio, and lower radiographic shoulder height (p = 0.01, 0.005, and 0.025, respectively) at the final follow-up. The Scoliosis Research Society (SRS)-30 Questionnaire scores were equivalent between the two groups. Correlation analysis showed that the following parameters were significantly associated with UIV translation: MT curve correction rate (r = -0.481, p = 0.015), chest cage ratio (r = 0.673, p < 0.001), and percent-predicted forced expiratory volume in 1 second (r = -0.455, p = 0.033).CONCLUSIONSThe UIV translation should be considered an important factor that influences postoperative results. In MT AIS patients whose preoperative upper end vertebra (UEV) is distant from the C7PL, the UIV should be selected above the UEV to prevent large UIV translation at the postoperative follow-up.

Segmental vs non-segmental thoracic pedicle screws constructs in adolescent idiopathic scoliosis: is there any implant alloy effect?

The aim of this study is to understand how many anchor sites are necessary to obtain maximum posterior correction of idiopathic scoliotic curve and if the alloy of instrumentation, stainless steel or titanium, may have a role in the percent of scoliosis correction. We reviewed 143 consecutive patients, affected by AIS (Lenke 1-2), who underwent a posterior spinal fusion with pedicle screw-only instrumentation between 2002 and 2005. According to the implant density and alloy used we divided the cohort in four groups. All 143 patients were reviewed at an average follow-up of 7, 2years, the overall final main thoracic curve correction averaged 61.4%, whereas the implant density within the major curve averaged 71%. A significant correlation was observed between final% MT correction and preoperative MT flexibility and implant density. When stainless steel instrumentation is used non-segmental pedicle screw constructs seem to be equally effective as segmental instrumentations in obtaining satisfactory results in patients with main thoracic AIS. When the implant alloy used is titanium one, an implant density of ≥60% should be guaranteed to achieve similar results.

Key-Vertebral Screws Strategy for Main Thoracic Curve Correction in Patients With Adolescent Idiopathic Scoliosis.

The following study was a prospective radiographic and retrospective clinical data assessment of adolescent idiopathic scoliosis (AIS) patients who had undergone a key-vertebral screws strategy (KVSS) at a single institution, with a minimum of 2 years' follow-up. The aim of the study was to introduce the KVSS for the operative treatment of AIS of the main thoracic curve, and to address the role of the fulcrum-bending radiograph (FBR) in predicting the outcome of surgical management by this method. The application of multilevel pedicle screws for the main thoracic curve in AIS patients is popular in an effort to provide spinal stability, enhance fusion outcome, and provide optimal curve correction. However, with the application of pedicle screw also comes a potential risk for soft tissue and neural injury and increased health care costs. It remains unknown whether limited screw placement can provide proper curve correction without compromising patient outcome. A total of 17 consecutive patients with AIS extending to the main thoracic spine, who had undergone posterior fusion and fixation by the KVSS, a procedure in which screws are placed at important strategic points in the spine (ie, bilaterally at the upper and lower end segments of the fusion block, apical vertebra on the convex side, adjacent cephalad, and caudal screw placement on the concave side), at a single institution, with a minimum of 2 year' follow-up, were included. The assessment of preoperative standing posteroanterior and sagittal, FBR, and postoperative standing posteroanterior and sagittal plain radiographs were assessed in all patients. The flexibility of the curve as well as the fulcrum-bending correction index (FBCI) were calculated for all patients. Postoperatively, radiographs were assessed at the immediate (ie, 1 wk) and last follow-up. Clinical assessment entailed evaluation of patient demographics and the presence of any intraoperative or postoperative complications. The mean age at the time of surgery was 15.6 years. The mean follow-up was 39.8 months. The average FBR flexibility was 62.2%. The mean immediate curve correction was 71.2%, which did not differ in comparison with the last follow-up assessment (P>0.05). The mean immediate and last follow-up FBCIs were 119.3% and 112.5%, respectively (P=0.079). A significant negative correlation was found between immediate FBCI to that of the FBR curve flexibility (r=-0.706; P=0.002), which remained similar on the last follow-up (r=-0.681; P=0.003). Sagittal alignment did not significantly change from the immediate to last follow-up (P=0.163) Fusion was achieved in all patients. No instrumentation-related complications were noted. Key-vertebral screws strategy is a safe and cost-effective method for the surgical treatment of the main thoracic curve in AIS patients. Moreover, in the context of this strategy, the FBR may have some predictive utility in the correction of the main thoracic curve in AIS patients.

Maintenance of spontaneous lumbar curve correction following thoracic fusion of main thoracic curves in adolescent idiopathic scoliosis.

The aims of our study were to provide long-term information on the behaviour of the thoracolumbar/lumbar (TL/L) curve after thoracic anterior correction and fusion (ASF) and to determine the impact of ASF on pulmonary function. A total of 41 patients (four males, 37 females) with main thoracic (MT) adolescent idiopathic scoliosis (AIS) treated with ASF were included. Mean age at surgery was 15.2 years (11 to 27). Mean follow-up period was 13.5 years (10 to 18). For the TL/L curve, the mean curve flexibility evaluated with supine pre-operative bending radiographs was 78.6% (standard deviation 16.5%), with no significant loss of correction observed. On comparing patients with an increase of the TL/L curve increase (> 4º, n = 9, 22%) to those without, significant differences were observed in the correction rate of the MT curve at the final follow-up (p = 0.011), correction loss of the MT curve (p = 0.003) and the proportion of patients who had semi-rigid instrumentation (p = 0.003). Pre-operative percentage predicted forced vital capacity (%FVC) was 80%, dropping to 72% at final follow-up (p < 0.001). The Scoliosis Research Society questionnaire score was not significantly different between patients with and without a TL/L curve increase (p = 0.606). Spontaneous lumbar curve correction (SLCC) was maintained up to 18 years following selective ASF in most patients and demonstrated significant correlation with maintenance of MT curve correction. Maintenance of MT curve correction using rigid instrumentation provided stable SLCC over time. An observed 8% decrease in %FVC indicates that ASF should be reserved for patients with no or only mild pulmonary impairment. Cite this article: Bone Joint J 2016;98-B:997-1002.

Posterior Selective Fusion with Pedicle Instrumented Correction in Thoracic and Thoracolumbar Idiopathic Scoliosis

Introduction To evaluate clinical and radiological outcome of selective fusion for adolescent idiopathic scoliosis (AIS) in thoracic and thoraco-lumbar curves i.e., Lenke 1C and 5C curves. Material and Methods 32 consecutive patients (22 females, 10 males) with 20 Lenke 1 C and 12 Lenke 5C were operated through posterior approach for AIS. Risser stage at the time of operation was 0–3 in 24patients and more than 3 in 4patients. Mean age was 13.5 years. Not every vertebra was instrumented with pedicle screws. Apical vertebral derotation and translation on the concave side were performed for correction. All patients underwent a selective fusion (1C only thoracic curve fused; 5C only thoracolumbar/lumbar curve fused). The data were prospectively collected preoperatively and at 6 weeks, 1year and 2 years post-operatively. Cobb angle, sagittal and coronal balance, and lowest fused vertebral tilt were documented at all time-points. Uninstrumented compensatory curves were measured at all time points. Results Lowest instrumented vertebra (LIV) was distal end vertebra in 15 patients and was one below distal end vertebra in 3 patients in Lenke1C curves. The main thoracic curve correction in Lenke1C was 66%, from 60° ± 12° preoperative to 20° ± 7° at 6 weeks. The Cobb angle was 20° ± 10° at 1 years and 24° ± 10° at 2 years. The apical vertebral rotation improved by 38%, the non-instrumented lumbar curves improved 50%. The last instrumented vertebral tilt decreased from 22° ± 8° preoperatively to 5° ± 5° postoperatively. The average thoracolumbar/lumbar (TL/L) preoperative Cobb angle in Lenke5C curves was 46° ± 8° which was corrected to 14° ± 7° (70% correction) at a 2-year follow-up. 25% of the uninstrumented thoracic curve had spontaneous correction. The coronal balance improved significantly ( p &lt; 0.05) and remained stable from the first postoperative visit to the 2-year follow-up visit. The SRS-22 total scores improved significantly from before surgery to 2years after surgery ( p &lt; 0.0001). No pseudarthrosis or reoperation was observed. One 12 girl with Lenke1C (65°) had intra-operative loss of neural monitoring signals who was paralysed postoperatively for a period of 2 weeks. She recovered completely by 2 months. Conclusion Posterior correction of thoracic and thoracolumbar AIS with pedicle screw instrumentation is safe and produces a long-term stable correction and high patient satisfaction. In Lenke 1C and 5C AIS deformity patterns fused selectively, the uninstrumented compensatory curves do not seem to progress. Selective fusions, when successfully performed, will optimize mobile segments of the spine in AIS patients.

Is there a better derotation manoeuvre in posterior correction of thoracic adolescent idiopathic scoliosis?

Background Retrospective review of 62 consecutive patients affected by AIS (Lenke type 1 or 2) treated by posterior fusion with pedicle screw-only instrumentation. Three groups identified: Pre-Rod (direct derotation procedure done before inserting rods), Single-Rod (derotation done after concave rod insertion) Double-Rod (after both rods). The Pre-Rods insertion cases showed a significantly better final correction of apical vertebral rotation (61.9% vs 55.8% and 50.1%) and a greater final correction of main thoracic curve. Different manoeuvres can be adopted for direct derotation in posterior correction of thoracic adolescent idiopathic scoliosis (AIS). Aim of the study is to evaluate the better manoeuvre in AIS posterior surgery.

Comparison of anterior and posterior vertebral column resection versus anterior release with posterior internal distraction for severe and rigid scoliosis

This study aimed to compare efficacy, safety, and cost between staged vertebral column resection (VCR) and anterior release with internal distraction in treating severe and rigid idiopathic scoliosis. We examined the records of 43 patients with severe and rigid idiopathic scoliosis treated in our hospital. Group A included 26 patients who underwent anterior VCR followed by posterior vertebral column resection and instrumentation from July 2007 to October 2009. Group B included 17 patients who underwent anterior release with temporary posterior internal distraction, followed by posterior fusion and instrumentation from November 2009 to June 2011. The average preoperative main curve for group A was 101.3° (range 90°-130°) and for group B was 104.8° (range 90°-136°). Minimum follow-up was 2 years. Radiographic and clinical outcomes were compared between the groups. A t test demonstrated that the differences between the groups in preoperative and postoperative coronal and sagittal imbalance, thoracic kyphosis correction, and lumbar lordosis were not statistically significant. Patients in group B showed better postoperative (P = 0.031) and final (P = 0.030) main thoracic curve correction (76.8 and 75.6 %, respectively) than patients in group A (68.3 and 67.7 %, respectively). Patients in group B had better thoracolumbar or lumbar curve correction (85.8 %) than those in group A (76.8 %; P = 0.048). The differences in blood loss and operation time were not statistically significant (P = 0.094 and P = 0.060, respectively). Hospital stay was longer (P = 0.001) and patient cost was higher (P < 0.001) for patients in group B. One patient in group A required ventilator support for 12 h after anterior surgery. One transient dyspnea occurred in group B. No neurologic deficits occurred in either group. Anterior release with posterior internal distraction produces better corrective effects than anterior and posterior VCR, though hospital stay and costs are greater.

Do Anchor Density or Pedicle Screw Density Correlate With Short-Term Outcome Measures in Adolescent Idiopathic Scoliosis Surgery?

Retrospective review. Determine if factors under surgeon control (anchor density or pedicle screw density) or those not under surgeon control (curve magnitude, levels requiring fusion, and curve flexibility) correlate with standard, short-term quality and outcome measures for adolescent idiopathic scoliosis. Pedicle screw fixation has revolutionized posterior spinal instrumentation and fusion for adolescent idiopathic scoliosis and seems to provide greater radiographical coronal plane curve correction than less expensive constructs. Other clinically relevant improvements in outcome have been difficult to demonstrate. Retrospective review of 119 posterior spinal instrumentation and fusion cases for adolescent idiopathic scoliosis by 4 surgeons at 1 institution. Average follow-up was 586.7 days. Outcome measures were main thoracic curve correction, complications, reoperations, infection, intensive care unit days, length of stay, estimated blood loss, transfusion, procedure time, implant charges, and total hospital charges. "Surgeon-dependent" variables were implant density (fixation/instrumented level) and pedicle coefficient (implant density × percentage of anchors that are pedicle screws). "Surgeon-independent" variables were main thoracic curve magnitude, main thoracic curve flexibility, and levels fused. Correlations were estimated using Pearson correlation coefficients. One-way analysis of variance was used to estimate the effect of "type of surgeon" or "surgeon" on surgeon-dependent variables. Complications, reoperations, and infections did not correlate with surgeon-dependent or surgeon-independent variables. Main thoracic curve correction correlated strongly with curve flexibility (correlation coefficient [cc] = 0.4089, P < 0.0001). Surgeon-independent variables were levels fused correlated significantly with procedure time (cc = 0.610, P < 0.001), hospital charges (cc = 0.309, P < 0.001), hospital length of stay (cc = 0.366 [P < 0.001]), implant charges (cc = 0.199, P < 0.047), and estimated blood loss (cc = 0.243, P < 0.013). Surgeon-dependent variables were implant density significantly correlated with implant charges (cc = 0.243, P < 0.015) and inversely with length of stay (cc = -0.236, P < 0.015). Pedicle coefficient was not significantly correlated with any outcome measure. Levels fused, a surgeon-independent variable, had the most consistently strong correlations with standard short-term quality indicators. With physician grading by payers largely dependent on easily measured outcomes from medical records, hospital and billing records, physicians need to be aware of the surgeon-dependent and surgeon-independent variables that may affect their outcomes and cost-effectiveness profile. 3.

An Innovative Fulcrum-Bending Radiographical Technique to Assess Curve Flexibility in Patients With Adolescent Idiopathic Scoliosis

A prospective clinical and radiographical study. To introduce a redesigned fulcrum-bending radiographical (FBR) method, and to validate the effectiveness of this method in assessing patients with (AIS). Several radiographical methods exist to evaluate curve flexibility in patients with AIS. The technique of FBR has been demonstrated to better predict coronal plane correction of main thoracic curves. However, the amount of weight applied may affect the results of flexibility evaluation and have not been well studied to date. Seventeen patients with AIS with 19 curves were involved in this study. The assessment of radiographs included preoperative standing posterior-anterior, supine side-bending, traditional FBR, new FBR (CH-FBR), and postoperative standing posterior-anterior radiographs. CH-FBR was performed at variable device heights while measuring the applied weight at the apex. Preoperatively, the mean Cobb angle was 47.5° ± 8.8° on the posterior-anterior radiographs, 14.3° ± 7.0° on supine side-bending radiographs, 13.3° ± 5.7° on traditional FBR, 11.3° ± 4.5° at the lowest height using CH-FBR (lowest weight), and 7.8° ± 4.1° at the optimized height using CH-FBR (maximal weight). Postoperatively, the mean Cobb angle was 9.1° ± 5.2°. There was a significant difference found between supine side-bending radiograph and postoperative Cobb angle (P = 0.001), traditional FBR, and postoperative Cobb angle (P = 0.002). There was no significant difference found between optimized height CH-FBR and postoperative Cobb angle (P = 0.16). Correlation analysis indicated that the maximum height of CH-FBR positively correlated with maximum weight applied (r = 0.68, r= 0.46, P = 0.001). CH-FBR is a more reliable and effective method than traditional FBR and supine side-bending radiographs to measure curve flexibility in patients with AIS. Moreover, the flexibility suggested by the CH-FBRs more closely approximated the postoperative results from posterior pedicle screw instrumentation. 3.

En Bloc Vertebral Column Derotation Provides Spinal Derotation But No Additional Effect on Thoracic Rib Hump Correction as Compared With No Derotation in Adolescents Undergoing Surgery for Idiopathic Scoliosis With Total Pedicle Screw Instrumentation

A comparative review of 2 cohorts with prospective data collection. To compare clinical and radiographical parameters in patients with adolescent idiopathic scoliosis undergoing surgery, using total pedicle screw instrumentation with and without en bloc vertebral column derotation (DVR). All pedicle screw instrumentations with or without DVR are an effective surgical method for adolescent idiopathic scoliosis correction. However, there are limited data comparing pedicle screw instrumentation alone with pedicle screws with DVR on clinical and radiographical outcomes. We followed 72 consecutive children and adolescents (14 males, mean age at surgery: 14.7 [range, 9.0-18.0] years; 6 juveniles, 66 adolescents) operated for a structural thoracic idiopathic scoliosis (Lenke 1-4, or 6) using all pedicle screw construct in a prospective manner for a minimum of 2 years. Of them, 24 had pedicle screw instrumentation with apical monoaxial screws without derotation (N-DVR) and 48 with en bloc DVR. Preoperatively, the mean (SD) main thoracic curve was 56° ± 9° and 57° ± 11° and was corrected to 16° ± 6° in both groups at 2-year follow-up (not significant). Thoracic rib hump averaged 12.3° ± 3.6° versus 14.2° ± 5.0° (P = 0.075) preoperatively and 7.2° ± 3.8° versus 8.3° ± 3.7° at 2-year follow-up in the N-DVR and in the DVR both groups, respectively (P = 0.30). Correction of spinal rotation in the main thoracic curve as assessed by the Upsani score was significantly better in the DVR group than in the N-DVR group at 6 months (P = 0.038) and 2-year follow-up (P = 0.039). Thoracic kyphosis reduced from a mean of 23° ± 18° to 20° ± 9° in the N-DVR group but remained unchanged in the DVR group (P = 0.11 between groups at 2-year follow-up). En bloc DVR has a significant effect on radiographical spinal column derotation and may help prevent flattening of thoracic kyphosis, but this derotation is not reflected by better thoracic rib hump correction at 2-year follow-up. 2.