Postoperative Coronal Decompensation Research Articles

Two-stage surgery with oblique lateral interbody fusion and posterior fixation in degenerative scoliosis with lumbosacral curve-driven degenerative lumbar scoliosis: a feasible option to prevent postoperative coronal decompensation

ObjectiveThis study aims to introduce a two-stage surgical procedure, namely oblique lateral interbody fusion (OLIF), for spinal disorders treatment. Furthermore, clinical outcomes and imaging results are analyzed between OLIF with posterior fixation and posterior lumbar interbody fusion (PLIF) with fixation for lumbosacral curve-driven degenerative lumbar scoliosis (DLS).Methods146 patients with type 2 DLS who underwent OLIF or PLIF between January 2019 and November 2023 were included. Spinal and pelvic parameters were measured using X-ray imaging before and after surgery. Clinical symptoms were assessed using Oswestry Disability Index (ODI) and visual analog scale (VAS). Operation time, intraoperative blood loss, surgical fixation segments, drainage tube indwelling time, and drainage volume were recorded.Results70 patients underwent OLIF and 76 underwent PLIF. Preoperative and postoperative clinical symptoms remain the same (p > 0.05). OLIF group exhibited significantly less intraoperative blood loss, fewer fixation segments, shorter drainage tube retention time, and reduced drainage volume (p < 0.01). Additionally, improvements in coronal parameters, including coronal balance distance, were more pronounced in OLIF group with less potential postoperative coronal imbalance (p < 0.05).ConclusionFor type 2 DLS, two-stage surgery of OLIF with posterior fixation represents a more efficient surgical approach, reducing surgical fusion segments, causing less trauma and bleeding, and effectively avoiding postoperative coronal plane decompensation than traditional posterior surgery.

Perioperative Considerations in Patients with Rett Syndrome as Compared to Those with Cerebral Palsy.

Retrospective cohort study. This study aimed to compare perioperative outcomes of Rett syndrome and Cerebral palsy patients undergoing posterior spinal fusion for neuromuscular scoliosis. Surgical correction in the treatment of scoliosis for patients with Rett syndrome (RS) has been shown to increase survival rate. Cerebral palsy (CP) patients, like RS patients, are often nonverbal, nonambulatory, with frequent surgical complications. Retrospective review of 36 RS and 80 CP patients undergoing PSF from 2005-2023. Data and x-ray measurements were collected pre- and post-operatively. Sub-analysis was performed comparing non-ambulatory patients (GMFCS IV-V). Wilcoxon-Rank Sum, Fisher's Exact, and Chi-square tests were utilized. The primary outcome measure, complication rates, was similar between the groups (P=0.09). Preoperative Cobb angle, levels fused, fixation points, and LOS were similar (P>0.05). EBL was significantly higher in CP patients as was rate of transfusion (P=0.001) and surgical time (P=0.001). Postoperative Cobb angle (P=0.002) was significantly higher for CP patients. There was no significant difference between CP and RS patients in both preoperative (P=0.383) and postoperative (P=0.051) coronal decompensation. Nonambulatory status was associated with increased odds of having a postoperative complication (OR=6.17, 95% C.I. 1.36 - 28.04). Sub-analysis of non-ambulatory RS and CP patients revealed significantly higher postoperative Cobb (P=0.008), EBL (P=0.019) and surgical time (P=0.017) in CP patients compared to RS patients. There were no significant differences in preoperative Cobb, levels fused, fixation points, hospital stay, or complication rate (P>0.05). RS patients are shown to have better outcomes to CP patients in terms of surgical, perioperative, and radiographic variables. Ambulatory status was identified as an independent risk factor for complications.

Appropriate pelvic obliquity measurement method in Lenke type 5C adolescent idiopathic scoliosis: a preliminary study.

Although pelvic obliquity (PO) is a risk factor for postoperative coronal decompensation in corrective surgery in adolescent idiopathic scoliosis (AIS), especially Lenke 5C, methods of measuring PO are controversial. This study aimed to establish an appropriate measurement method using multiplanar reconstructed computed tomography (MPR-CT) images instead of standing posteroanterior (PA) whole-spine radiographs to evaluate PO in patients with Lenke 5C AIS. This study was a retrospective cross-sectional study. Twenty-five patients who underwent corrective surgery for AIS in Osaka University Hospital from August 2014 to February 2023 were included. Cobb angle, L5 tilt, C7 plumb line to center sacral vertebral line (C7PL-CSVL), and leg length discrepancy (LLD) were measured on standing PA whole-spine radiographs preoperatively. Sacral obliquity (SO), the slope of the upper endplate of S1, and iliac obliquity (IO), the tilt of the line connecting the iliac crests, were measured on standing PA whole-spine radiographs and MPR-CT (SO/IO-X-ray, SO/IO-CT, respectively). S1 angle and S2 angle were measured on CT. The mean age of the patients was 18.7±3.9 years and all of them were females. SO-X-ray and SO-CT were larger than IO-X-ray and IO-CT, respectively. SO-X-ray was highly correlated with SO-CT (r=0.838, P<0.001). L5 tilt had higher correlation with SO-CT (r=0.884, P<0.001) than with SO-X-ray (r=0.726, P=0.001) and IO-CT (r=0.550, P=0.22). L5 tilt was correlated poorly with IO-X-ray (r=0.104, P=0.69). The S1 angle was 4.5±3.5° meanwhile the S2 angle was 1.2±2.1°, the sacral deformity was mainly due to the S1 vertebral wedging. Given the asymmetric sacral morphology, SO is more appropriate pelvic parameter than IO to represent the sacral tilt of Lenke 5C AIS, especially when measured using CT images to overcome the poor visibility on PA whole-spine radiographs.

Hyper-Selective Posterior Fusion is Recommended When the Modified S-Line is Positive in Lenke 5C Adolescent Idiopathic Scoliosis.

Postoperative coronal decompensation and less fusion level are dilemmas and the proper selective posterior fusion (SPF) strategy should be investigated. We proposed a parameter, modified S-line, and aimed to investigate if the modified S-line could predict postoperative coronal decompensation in patients with Lenke 5C adolescent idiopathic scoliosis (AIS). This is a retrospective radiographic study and Lenke 5C AIS patients undergoing SPF during the period from September 2017 to June 2021 were included. The modified S-line was defined as the line linking the centers of the concave-side pedicles of the upper end vertebra (UEV) and lower end vertebra (LEV) at baseline. A modified S-line tilt to the right is established as modified S-line+ (UEV being to the right of the LEV). The patients were further categorized into two groups: the Cobb to Cobb fusion group and the Cobb-1 to Cobb fusion group. Outcomes including thoracic Cobb angle, TL/L Cobb angle, coronal balance, upper instrumented vertebra (UIV) translation, lower instrumented vertebra (LIV) translation, UIV tilt, LIV tilt, LIV disc angle, thoracic apical vertebral translation, lumbar apical vertebral translation (L-AVT), L-T AVT ratio, L-T Cobb were measured at baseline, immediately after surgery, and the last follow-up. Radiographic parameters and the incidence of both proximal and distal decompensation between the two groups were compared by chi-square test. Among 92 patients, 48 were modified S-line+ and 44 were modified S-line-. Modified S-line+ status was identified as a risk factor for postoperative proximal decompensation (p = 0.005) during follow-up. In Cobb to Cobb group, a higher occurrence of proximal decompensation in individuals with modified S-line+ status (p = 0.001) was confirmed. Also, in the Cobb to Cobb group with baseline modified S-line+ status, patients presenting decompensation showed a significantly larger baseline of the UIV tilt and postoperative disc angle below the lower instrumented vertebra. However, In Cobb-1 group, the incidence of decompensation after surgery showed no association with baseline modified S-line tilt status (p = 0.815 and 0.540, respectively). The modified S-line could serve as an important parameter in surgical decision-making for Lenke 5C AIS patients. Cobb to Cobb SPF is not recommended with a modified S-line+ status, and the Cobb-1 to Cobb fusion may serve as a potential alternative.

Coronal decompensation following thoracic vertebral body tethering in idiopathic scoliosis.

Post-operative coronal decompensation (CD) continues to be a challenge in the treatment of adolescent idiopathic scoliosis (AIS). CD following selective spinal fusion has been studied. However, there is currently little information regarding CD following Vertebral Body Tethering (VBT). Thus, the goal of this study is to better understand the incidence and risk factors for CD after VBT. Retrospective review of a prospective multicenter database was used for analysis. Inclusion criteria were patients undergoing thoracic VBT, a minimum 2-year follow-up, LIV was L1 or above, skeletally immature (Risser ≤ 1), and available preoperative and final follow-up AP and lateral upright radiographs. Radiographic parameters including major and minor Cobb angles, curve type, LIV tilt/translation, L4 tilt, and coronal balance were measured. CD was defined as the distance between C7PL and CSVL > 2cm. Multiple logistic regression model was used to identify significant predictors of CD. Out of 136 patients undergoing VBT, 94 patients (86 female and 6 male) met the inclusion criteria. The mean age at surgery was 12.1 (9-16) and mean follow-up period was 3.4years (2-5years). Major and minor curves, AVR, coronal balance, LIV translation, LIV tilt, L4 tilt were significantly improved after surgery. CD occurred in 11% at final follow-up. Lenke 1A-R (24%) and 1C (26%) had greater incidence of CD compared to 1A-L (4%), 2 (0%), and 3 (0%). LIV selection was not associated with CD. Multivariate logistic regression analysis yielded 1A-R and 1C curves as a predictor of CD with the odds ratio being 17.0. CD occurred in 11% of our thoracic VBT patients. Lenke 1A-R and 1C curve types were predictors for CD in patients treated with VBT. There were no other preoperative predictors associated with CD.

Global Coronal Malalignment in Degenerative Lumbar Scoliosis and Priority-Matching Correction Technique to Prevent Postoperative Coronal Decompensation.

A prospective case-control study. To analyze global coronal malalignment (GCM) in degenerative lumbar scoliosis (DLS) and to prospectively investigate the performance of priority-matching correction technique on preventing postoperative coronal imbalance. A total of 444 DLS inpatients and outpatients were recruited. GCMs were classified into 2 types: Type 1, GCM with thoracolumbar (TL/L) curve as the main contribution on coronal imbalance; Type 2, GCM with lumbosacral (LS) curve as the main contribution on coronal imbalance. Patients receiving priority-matching correction were assigned to Group P-M and receiving traditional correction were assigned to Group T form August 2020. The fundamental principle of priority-matching technique was to first correct the key curve contributing to coronal imbalance rather than the curve with greater magnitude. Type 1 GCM accounted for 45% and Type 2 GCM accounted for 55% of patients. Type 2 GCM was detected to have greater LS Cobb angle and L4 tilt. At 1-year follow-up, 29.8% of patients with Type 2 GCM, whereas 11.7% of patients with Type 1 GCM were observed to have postoperative coronal decompensation. Patients with postoperative imbalance were revealed to have greater preoperative LS Cobb angle and L4 tilt and smaller correction extent of LS curve and L4 tilt. 6.25% of patients developed postoperative coronal imbalance in Group P-M, whereas 40.5% developed in Group T. Highlighting priority and aggressive correction of the key curve to coronal imbalance, priority-matching technique was proved to be able to limit the development of postoperative coronal decompensation.

Surgical outcomes of posterior correction surgery for scoliosis associated with syringomyelia

ObjectiveAlthough syringomyelia is considered a risk factor for neurological complications of correction surgery for scoliosis, only a few reports on the surgical results of the correction surgery complicated with associated syringomyelia are available. The purpose of this study is to verify the potential risk of neurological complications due to the presence of syringomyelia and explore the factors affecting the surgical outcomes of posterior correction surgery for scoliosis associated with syringomyelia. MethodsThis is a retrospective observational study in a single university hospital setting. Among 754 consecutive patients who underwent posterior correction and fusion surgery for scoliosis from 2009 through 2018 in our institution, we identified 28 patients presenting with spinal syringomyelia on preoperative whole spine MRI. The identified cases comprised 14 males and 14 females aged 11 years to 23 years (14.0 ± 2.9 years), and those with wide-type syrinx within fused spinal levels had undergone surgery for syringomyelia beforehand. First, we investigated the occurrence rate of peri- and postoperative neurological complications. Then we explored the factors affecting the correction rate of the Cobb angle and the incidence of coronal decompensation. ResultsNeurological complication (transient sensory deficits in bilateral legs) occurred in one case with thoracic single curve and narrow-type syrinx, disappearing spontaneously within several weeks postoperatively. The cases with an L4 long curve (n = 3, including L4 in thoracolumbar long C-shaped curve) showed a significantly poor correction rate (38.7%, p = 0.003) and developed postoperative coronal decompensation. ConclusionsPrior treatment for wide-type syrinx located within the spinal fusion level effectively prevented severe neurological complications, and when treating cases with long-curve L4 scoliosis associated with syringomyelia, the surgeons should note the occurrence of postoperative coronal decompensation.

Preoperative pelvic obliquity: possible relation to postoperative coronal decompensation in thoracolumbar/lumbar adolescent idiopathic scoliosis.

Pelvic obliquity is frequently observed in patients with adolescent idiopathic scoliosis with thoracolumbar/lumbar (TL/L) curve. This study aimed to assess pelvic obliquity changes and their effects on clinical outcomes of posterior fusion surgery. Data in 80 patients (69 with type 5C and 11 with type 6C adolescent idiopathic scoliosis) who underwent posterior fusion surgery were retrospectively analyzed. Pelvic obliquity was defined as an absolute pelvic obliquity angle (POA) value of ≥ 3°. The patients were divided into groups according to preoperative pelvic obliquity. Moreover, patients with preoperative pelvic obliquity were divided based on POA change from preoperative values versus 2 years postoperatively. Patients were divided based on the presence of selective or nonselective TL/L fusion. Radiographic parameters and clinical outcomes were compared between these groups. Among 80 patients, 41 (51%) showed preoperative pelvic obliquity, and its direction was upward to the right for all cases. Coronal decompensation 2 years postoperatively was significantly elevated in patients with preoperative pelvic obliquity (p < 0.05). Thirty-two patients (40%) displayed pelvic obliquity 2 years postoperatively. Among 41 patients with preoperative pelvic obliquity, 22 patients (54%) were in the group with a decrease in POA, and 19 were in the group with no decrease. The group with no decrease in POA showed significant TL/L curve progression throughout the postoperative follow-up period. The patients with nonselective fusion showed a significantly lower incidence of pelvic obliquity at 2 years postoperatively. Postoperative coronal decompensation more frequently occurred in patients with preoperative pelvic obliquity than in those without pelvic obliquity preoperatively. In addition, postoperative pelvic obliquity changes may be related to residual lumbar curve behavior.

Selection of Fusion Level for Adolescent Idiopathic Scoliosis Surgery : Selective Fusion versus Postoperative Decompensation.

Adolescent idiopathic scoliosis (AIS), which is associated with an extensive range of clinical and radiological presentations, is the one of the most challenging spinal disorders. The goals of surgery are to correct the deformity in 3 dimensions and to preserve motion segments while avoiding complications. Despite the ongoing evolution of classification systems and algorithms for the surgical treatment of AIS, there has been considerable debate regarding the selection of an appropriate fusion level in AIS. In addition, there is no consensus regarding the exact description, relationship, and risk factors of coronal decompensation following selective fusion. In this review, we summarize the current concepts of selection of the fusion level for AIS and review the available information about postoperative coronal decompensation.

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

To validate the predictability of S-line in Lenke 5C patients. 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. 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). 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.

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

To determine potential risk factors for postoperative coronal imbalance following posterior osteotomy for adult scoliosis. 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. 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. 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.

Selective Thoracic Fusion for King-Moe Type II/Lenke 1C Curve in Adolescent Idiopathic Scoliosis: A Comprehensive Review of Major Concerns.

Introduction Controversies still exist in the surgical indications and outcomes of selective thoracic fusion (STF) for a primary thoracic curve with a compensatory large lumbar curve (King-Moe type II/Lenke 1C curve) in adolescent idiopathic scoliosis (AIS). Issues of the greatest concern regarding this curve type include curve criteria that indicate STF to prevent postoperative coronal decompensation and postoperative radiographic outcomes, including curve correction, coronal balance, and thoracolumbar kyphosis, after STF. Methods This review comprehensively documents the issues raised in the literature regarding surgical indications and radiographic outcomes of STF for King-Moe type II/Lenke 1C curve in AIS. Results Studies suggest that radiographic curve criteria indicating STF for this curve type include the preoperative dominance of the thoracic curve to the lumbar curve in the Cobb angle and the characteristics of the lumbar curve in magnitude and flexibility. Studies warn the need for a careful clinical evaluation of the thoracic and lumbar rotational prominences. Documented radiographic outcomes of importance include the postoperative behavior of the unfused lumbar curve, coronal or sagittal decompensation after STF, and factors associated with these issues. A comprehensive review of the literature suggests that the use of a segmental pedicle screw construct and better instrumented thoracic curve correction achieve better spontaneous lumbar curve correction. Although the causes of postoperative coronal decompensation remain multifactorial, preoperative coronal decompensation to the left and an inappropriate selection of the lowest instrumented vertebra are consistently reported to be the major causative factors. Conclusions STF has been validated in general for the treatment of King-Moe type II or Lenke 1C curve in AIS; however, controversies remain regarding the surgical indications and outcomes. Long-term impacts of residual lumbar curve, coronal decompensation, and mild thoracolumbar kyphosis on clinical outcomes after STF, along with optimal indications and strategy for STF, should further be assessed.

Coronal Decompensation After Posterior-only Thoracolumbar Hemivertebra Resection and Short Fusion in Young Children With Congenital Scoliosis.

A retrospective study. To determine the incidence and risk factors of coronal decompensation after posterior-only thoracolumbar hemivertebra (HV) resection and short fusion in patients younger than 5-years old. Postoperative coronal decompensation may occur in operated patients during the follow up. However, there is a paucity of valid data regarding this complication in very young patients with thoracolumbar HV. This study reviewed a consecutive series of patients (younger than 5 years) who had undergone posterior-only hemivertebrectomy and short fusion from January 2006 to December 2014. They had a minimum follow-up of 24 months. According to the coronal compensation behavior, they were divided into two groups: Group P (progressed, curve decompensated beyond twenty degrees) and Group NP (nonprogressed, curve well compensated). There were 179 patients included in this study. Mean age at surgery was 38 ± 11 months. Mean follow-up was 41 ± 11 months. Postoperative coronal decompensation was identified in 18 patients (rate, 10.1%) who constituted Group P. The remaining 161 patients had a well-compensated pattern. In contrast to Group NP, the patients in Group P had greater preoperative lowest instrumented vertebra (LIV) translation (18.5 mm ± 6.4 mm vs. 10.5 mm ± 4.9 mm, P < 0.01), and higher postoperative LIV disc angle (7.0° ± 3.1° vs. 3.1° ± 3.3°, P < 0.01) after surgery. During the follow up, LIV translation and LIV disc experienced continuous aggravation until initiation of bracing. Preoperative LIV translation (≥15.1 mm) and postoperative LIV disc angle (≥5.5°) were identified as two independent risk factors of coronal decompensation after surgery. After thoracolumbar hemivertebrectomy in children younger than 5 years, the overall rate of coronal decompensation is approximately 10.1%. As two independent risk factors of postoperative coronal decompensation, preoperative LIV translation (≥15.1 mm) and postoperative LIV disc angle (≥5.5°) should on all accounts be the major causes for concern. 4.

Onset and remodeling of coronal imbalance after selective posterior thoracic fusion for Lenke 1C and 2C adolescent idiopathic scoliosis (a pilot study)

BackgroundPostoperative coronal imbalance is a significant problem after selective thoracic fusion for primary thoracic and compensatory lumbar curves in adolescent idiopathic scoliosis (AIS). However, longitudinal studies on postoperative behavior of coronal balance are lacking. This multicenter retrospective study was conducted to analyze factors related to onset and remodeling of postoperative coronal imbalance after posterior thoracic fusion for Lenke 1C and 2C AIS.MethodsTwenty-one Lenke 1C or 2C AIS patients, who underwent posterior thoracic fusion ending at L3 or above, were included with a minimum 2-year follow-up. The mean patients’ age was 15.1 years at the time of surgery. Radiographic measurements were performed on Cobb angles of the main thoracic (MT) and thoracolumbar/lumbar (TLL) curves and coronal balance. Factors related to the onset of immediately postoperative coronal decompensation (IPCD) and postoperative coronal balance remodeling (PCBR), defined as an improvement of coronal balance during postoperative follow-up, were investigated using comparative and correlation analyses.ResultsMean Cobb angles for the MT and TLL curves were 57.3° and 42.3° preoperatively and were corrected to 22.8° and 22.5° at final follow-up, respectively. Mean preoperative coronal balance of −3.8 mm got worse to −21.2 mm postoperatively, and regained to −12.0 mm at final follow-up. Coronal decompensation was observed in two patients preoperatively, in ten patients immediately postoperatively, and in three patients at final follow-up. The preoperative coronal balance and lowest instrumented vertebra (LIV) selection relative to stable vertebra (SV) were significantly different between patients with IPCD and those without. PCBR had significantly negative correlation with immediately postoperative coronal balance.ConclusionsIPCD after posterior thoracic fusion for Lenke 1C and 2C AIS was frequent and associated with preoperative coronal balance and LIV selection. However, most patients with IPCD regained coronal balance through PCBR, which was significantly associated with immediately postoperative coronal balance. A fixation more distal to SV shifted the coronal balance further to the left postoperatively.

Assessment of Coronal Radiographic Parameters of the Spine in the Treatment of Adolescent Idiopathic Scoliosis.

To determine the most important preoperative factors that affect postoperative coronal parameters of scoliotic curves. All Adolescent Idiopathic Scoliosis (AIS) patients included in the study were classified according to Lenke and King Classification. The fusion levels were selected according to the rigidity of the existing curves (correction less than 50%), tilt of T1 and shoulders, sagittal angle of the curves and with considering stable and neutral end vertebra. The radiographic coronal parameters: shoulders tilt angle, iliolumbar angle and coronal balance were measured in all patients before, after, and in the last follow-up visit. One hundred twenty patients after mean of 25 months follow-up (18-40 months) were included in the study. Before operation, abnormal coronal balance (more than 2 cm shift) was noticed in 46 patents (38%) and in the last visit, was noted in 22 patients (18%). Multivariate regression analysis revealed a significant predictive value of the preoperative coronal balance on the last visit coronal balance (P value=0.01). Preoperative coronal balance is very important to make a balanced spine after surgery. Other parameters like Lenke classification or main thoracic overcorrection did not affect postoperative coronal decompensation.

Postoperative behavior of thoracolumbar/lumbar curve and coronal balance after posterior thoracic fusion for Lenke 1C and 2C adolescent idiopathic scoliosis

Background Controversy still exists around surgical strategies for Lenke type 1C and 2C curves with primary thoracic and compensatory lumbar curves in adolescent idiopathic scoliosis (AIS). The benefit of selective thoracic fusion (STF) for these curve types is spontaneous lumbar curve correction while saving more mobile lumbar segments. However, a risk of postoperative coronal decompensation after STF has also been reported. This multicenter retrospective study was conducted to evaluate postoperative behavior of thoracolumbar/lumbar (TLL) curve and coronal balance after posterior thoracic fusion for Lenke 1C and 2C AIS.

Risk Factors for Postoperative Coronal Decompensation after the Posterior Osteotomies in Adult Scoliosis

Coronal and sagittal decompensation following long fusions for spinal deformities can affect outcomes negatively. The risk factors for postoperative sagittal imbalance have been studies extensively. While little data were available on the risk factors for postoperative coronal imbalance, especially for the patients treated with osteotomies.

Postoperative behavior of thoracolumbar/lumbar curve and coronal balance after posterior thoracic fusion for Lenke 1C and 2C adolescent idiopathic scoliosis.

Controversy still exists around surgical strategies for Lenke type 1C and 2C curves with primary thoracic and compensatory lumbar curves in adolescent idiopathic scoliosis (AIS). The benefit of selective thoracic fusion (STF) for these curve types is spontaneous lumbar curve correction while saving more mobile lumbar segments. However, a risk of postoperative coronal decompensation after STF has also been reported. This multicenter retrospective study was conducted to evaluate postoperative behavior of thoracolumbar/lumbar (TLL) curve and coronal balance after posterior thoracic fusion for Lenke 1C and 2C AIS. Twenty-four Lenke 1C and 2C AIS patients who underwent posterior thoracic fusion were included. The mean age of patients was 15.7 years old at time of surgery. Constructs used for surgery in all cases were pedicle screw constructs ending at L3 or above. Radiographic measurements were performed on Cobb angles of the main thoracic and TLL curves and coronal balance. Factors related to final Cobb angle of TLL curve and postoperative change of coronal balance were investigated. Mean Cobb angles for main thoracic and TLL curves were 59.0° and 43.9° preoperatively, and were corrected to 21.5° and 22.0° at final follow-up, respectively. Mean coronal balance was -5.6 mm preoperatively and was corrected to -14.6 mm at final follow-up. Final Cobb angle of TLL curve was significantly correlated with immediate postoperative Cobb angle of main thoracic curve and tilt of lowest instrumented vertebra (LIV). Postoperative change of coronal balance was significantly correlated with selection of LIV relative to stable vertebra. Spontaneous correction of TLL curve occurred consistently by correcting the main thoracic curve and making the LIV more horizontal after posterior thoracic fusion for Lenke 1C and 2C AIS. The more distal fixation to stable vertebra resulted in coronal balance shifting more to the left postoperatively.

Is Decompensation Preoperatively a Risk in Lenke 1C Curves?

A review of a multicenter, prospective registry of patients surgically treated for adolescent idiopathic scoliosis. To investigate preoperative and postoperative distribution of coronal decompensation in Lenke 1C curves and to determine whether a selective thoracic fusion (STF) affects the results of coronal decompensation. Numerous causes of postoperative coronal decompensation in Lenke 1C curves have been reported; however, there are few reports focusing on preoperative decompensation and its relation to postoperative decompensation in Lenke 1C curves. Patients with Lenke 1C prospectively collected from a multicenter study were analyzed. Preoperatively, patients were grouped as decompensated (C7-CSVL > 2 cm) or balanced (C7-CSVL within 2 cm, where CSVL is central sacral vertical line). Preoperative distribution and factors for postoperative coronal decompensation were investigated. Seventy-one patients (53 STF, 18 nonselective fusions) were included. Preoperatively, coronal balance was skewed to the left (-17 ± 13 mm). Of the 21 STF decompensated to the left preoperatively, 12 (57%) remained to the left at 2 years. Postoperative thoracic correction was significantly better in those balanced postoperatively (57%) compared with those who remained decompensated (46%; P < 0.05). There were 32 STF patients who were balanced preoperatively, with 10 of these (31%) decompensated to the left at 2-year follow-up. This rate (31%) was significantly less than the group that was decompensated preoperatively (57%, P = 0.04). In the nonselective fusion group, 16 out of 18 patients (89%) were balanced at 2-year follow-up, independent of preoperative balance. Patients with Lenke 1C tended to be decompensated to the left preoperatively. In those decompensated preoperatively who underwent a STF, the majority remained greater than 2 cm to the left at 2-year follow-up. Patients with both thoracic and lumbar curves fused had better coronal balance at 2 years than selectively treated patients. Although not a contraindication to performing a selective fusion, treating surgeons should be prepared for modest coronal decompensation in 40% of patients with Lenke 1C treated with selective fusion of the thoracic curve alone. 3.

Selective fusion in adolescent idiopathic scoliosis

Selective fusion in adolescent idiopathic scoliosis