Selective Thoracic Fusion Research Articles

Usefulness of modified S-line for upper instrumented vertebra selection in adolescent idiopathic scoliosis Lenke type 1C curve.

Determine the effect of using the modified S-line vertebra (MSLV) as the upper instrumented vertebra (UIV) on postoperative trunk balance, L4 tilt, and clinical outcomes in selective thoracic fusion (STF) for adolescent idiopathic scoliosis (AIS) Lenke type 1C curve. Twenty-eight consecutive patients (all female; mean age: 15.4±2.0 years) with AIS Lenke type 1C curve were retrospectively enrolled. Primary outcome measures were coronal balance (absolute distance between C7 and the center of the sacral vertical line), L4 tilt, and Scoliosis Research Society (SRS)-22r scores at 2 years postoperatively. The group with the MSLV at the UIV was designated as the MSLV group (18 patients), and the group with the MSLV proximal (12 patients) or distal (4 patients) to the UIV was defined as the non-MSLV group. We observed no significant differences between the groups regarding age, LIV and stable vertebra positioning, or preoperative X-ray parameters. Postoperative coronal balance was significantly better in the MSLV group (0.39±0.08 vs. 1.34±0.22 cm; P.

The Optimal Lowest Instrumented Vertebra to Prevent the Distal Adding-On Phenomenon in Patients Undergoing Selective Thoracic Fusion for Adolescent Idiopathic Scoliosis with Lenke Type 1A and 1B Curves: Comparison of Nine Selection Criteria.

Background/Objectives: There is no solid consensus regarding which lowest instrumented vertebra (LIV) selection criterion is best to prevent distal adding-on (DA) after adolescent idiopathic scoliosis (AIS) surgery. This study aims to search out the LIV selection criteria in the literature and to compare the ability of each LIV selection criterion to prevent DA in patients with AIS. Methods: Patients who underwent thoracic fusion for AIS of Lenke type 1A or 1B were included in this study. Nine criteria for LIV selection were found in a literature review. For each patient, whether the postoperative actual location of LIV was met with the suggested locations of the LIV was assessed. The preventive ability of nine criteria against DA was evaluated using logistic regression analysis. The patients who met the LIV selection criteria but developed DA were investigated. Results: The study cohort consisted of 145 consecutive patients with a mean age of 14.8 years. The criteria of Suk (OR = 0.267), Parisini (OR = 0.230), Wang (OR = 0.289), and Qin (OR = 0.210) showed a significantly decreased risk of DA if the LIV selection criterion was chosen at each suggested landmark. As the additional levels were fused, there was no statistically significant benefit in further reducing the risk of DA. Among the patients who met each criterion, the incidence of DA was lower in criteria by Takahashi (5.9%), Qin (7.1%), and King (7.4%) than the others. Conclusions: Qin's criterion, using the substantially touching vertebra concept, has the highest preventive ability against DA development. Extending the instrumentation further distal to this suggested LIV criterion did not add further benefit.

Prediction Model for Lumbar Curve Correction After Selective Thoracic Fusion in Lenke 1 and 2 Adolescent Idiopathic Scoliosis.

A retrospective study. To identify independent risk factors and construct a prediction model for lumbar curve correction (LCC) after selective thoracic fusion (STF) in patients with Lenke 1 and 2 adolescent idiopathic scoliosis (AIS). STF has been widely applied to Lenke 1 and 2 AIS patients. However, LCC after STF is still controversial. One hundred twenty-eight patients undergoing STF with at least 2 years of follow-up were included. Cases were divided into a high-LCC group and a low-LCC group according to a rounded-up median of 65%. Forty-nine variables were taken into account. Logistic regression was applied to identify independent predictive factors. A prediction model was established by backward stepwise regression, and its evaluation was implemented on R. Five parameters showed independent predictive value for low LCC: right shoulder higher before surgery (right shoulder higher versus balanced: odds ratio [OR]=0.244, P =0.014), postoperative Cobb angle of lumbar curve (LC) (OR=1.415, P =0.001, cutoff value=11°), lowest instrumented vertebra (LIV) distal to end vertebra (no vs. yes: OR=4.587, P =0.013), postoperative LIV tilt (OR=0.686, P =0.010, cutoff value=6.85°) and postoperative LIV+1 tilt (OR=1.522, P =0.005, cutoff value=6.25°). The prediction model included 6 variables: lumbar modifier, preoperative shoulder balance, postoperative Cobb angle of LC, LIV position, postoperative LIV tilt, and postoperative LIV+1 tilt. The model evaluation demonstrated satisfactory capability and stability (area under curve=0.890, 10-fold cross-validation accuracy=0.782). Preoperative shoulder balance, Cobb angle of LC, LIV position, postoperative LIV and LIV+1 tilt could be used to prognosticate LCC after STF. A model with solid prediction ability was established, which could further our understanding of LCC and assist in making clinical decisions.

Lowest instrumented vertebrae in early onset scoliosis: is there a role for a more selective approach?

PurposeThis purpose of this study was to assess the impact of patient and implant characteristics on LIV selection in ambulatory children with EOS and to assess the relationship between the touched vertebrae (TV), the last substantially touched vertebrae (LSTV), the stable vertebrae (SV), the sagittal stable vertebrae (SSV), and the LIV.MethodsA multicenter pediatric spine database was queried for patients ages 2–10 years treated by growth friendly instrumentation with at least 2-year follow up. The relationship between the LIV and preoperative spinal height, curve magnitude, and implant type were assessed. The relationships between the TV, LSTV, SV, SSV, and the LIV were also evaluated.ResultsOverall, 281 patients met inclusion criteria. The LIV was at L3 or below in most patients with a lumbar LIV: L1 (9.2%), L2 (20.2%), L3 (40.9%), L4 (29.5%). Smaller T1 − T12 length was associated with more caudal LIV selection (p = 0.001). Larger curve magnitudes were similarly associated with more caudal LIV selection (p = < 0.0001). Implant type was not associated with LIV selection (p = 0.32) including MCGR actuator length (p = 0.829). The LIV was caudal to the TV in 78% of patients with a TV at L2 or above compared to only 17% of patients with a TV at L3 or below (p < 0.0001).ConclusionsMost EOS patients have an LIV of L3 or below and display TV–LIV and LSTV–LIV incongruence. These findings suggest that at the end of treatment, EOS patients rarely have the potential for selective thoracic fusion. Further work is necessary to assess the potential for a more selective approach to LIV selection in EOS.Level of evidenceIII.

3D analysis of the preoperative deformity in AIS can be used to guide surgical treatment decisions for selective thoracic fusion.

To identify 3D measures of scoliosis from preoperative imaging that are associated with optimal radiographic outcomes after selective thoracic fusion (STF) for adolescent idiopathic scoliosis (AIS). Subjects with primary thoracic curves (Lenke 1-4, B or C modifiers) fused selectively (L1 or above) who had preoperative 3D reconstructions and minimum 2 years of follow-up were included. An optimal outcome at 2 years was defined as having 4 of 5 parameters previously defined in the literature: (1) lumbar curve < 26º, (2) deformity flexibility quotient < 4, (3) C7-CSVL < 2cm, (4) lumbar prominence < 5º and (5) trunk shift < 1.5cm. Univariate and CART analyses were performed to identify preoperative variables associated with achieving an optimal outcome 2 years postoperatively. Ninety-nine (88F, 11M) patients met inclusion. Mean age was 15 ± 2years. Fifty-one subjects (52%) had an optimal outcome. Seven preoperative deformity measures representing smaller thoracolumbar/lumbar deformity in the optimal group were found to be significant on univariate analysis. CART analysis identified the following variables associated with optimal outcomes: difference in apical rotation > 30° = 27% optimal outcomes, difference in apical rotation ≤ 30° and coronal vertebral wedging of lumbar apex > 3° = 46% optimal outcomes, and difference in apical rotation ≤ 30° and coronal vertebral wedging of lumbar apex ≤ 3° = 80% optimal outcomes (p < 0.05). Optimal outcomes after STF were associated with a preoperative difference in apical vertebral rotation in the axial plane less than 30° between thoracic and lumbar curves as well as coronal plane vertebral wedging of the lumbar apical vertebra less than 3°.

Health-related Quality of Life (HRQOL) Outcomes of Selective/Nonselective Thoracic Fusion for Lenke 1C Adolescent Idiopathic Scoliosis (AIS) Patients with a Minimum 4-year Follow-up.

Both the selective thoracic fusion (STF) and nonselective thoracic fusion (NSTF) are treatments for Lenke 1C adolescent idiopathic scoliosis (AIS). To date, the impacts of the two surgical strategies on patients' long-term quality of life remain unclear. Therefore, the purpose of this study was to explore the long-term effects of STF/NSTF on the quality of life in Lenke 1C AIS patients through a 4-10-year follow-up. From January 2011 to April 2018, according to the inclusion and exclusion criteria, a retrospective single-center study of 75 surgical patients with Lenke 1C curves was performed (n = 75). They all underwent posterior fusion, and patients were divided into the selective thoracic fusion (STF) group (n = 42) and the nonselective thoracic fusion (NSTF) group (n = 33) based on their surgical approach. All participants received the survey of the visual analogue scale (VAS), SRS30, SF12, and Oswestry disability index (ODI) scales. Patients' gender, age, body mass index (BMI), surgical approach (STF/NSTF), surgical segments (UIV and LIV), follow-up time, complications, preoperative, postoperative, and last follow-up Cobb angles, and health-related quality of life (HRQOL) outcomes were collected, and analyzed through the Shapiro-Wilks test, Wilcoxon rank-sum test, t-test, and χ2 test. The mean follow-up of the entire cohort was 73 ± 5.6 months. The lumbar Cobb angle in the STF group improved from 31.8 ± 6.5° to 11.5 ± 5.1° after the operation and 10.3 ± 6.9° at the last follow-up. The postoperative correction rate of the lumbar curve was 63.8%, which increased to 67.7% at the last follow-up. In the NSTF group, the lumbar Cobb angle improved from 34.3 ± 11.3° to 4.3 ± 3.7° after the operation, and was 5.1 ± 3.1° at the last follow-up. The postoperative correction rate of the lumbar curve was 87.4%, and 85.1% at the last follow-up. At the last follow-up, the STF group had higher overall HRQOL scores than the NSTF group, and there were statistically differences between the different groups (STF/NSTF) in SRS-30-Mental health (p = 0.03), SRS-30-Satisfaction with management (p = 0.02), SRS-30-Pain (p = 0.03), ODI (p = 0.01), SF-12 PCS (p = 0.03), VAS back pain (p = 0.005) and VAS leg pain (p = 0.001). No statistically differences were found in SF12 MCS, SRS-30-Self-image/Appearance and SRS-30 Function/activity. After 4-10 years of follow-up, we found that the STF group achieved satisfactory correction results, and compared with the NSTF group, their overall HRQOL scores were higher, especially in terms of pain and satisfaction, where the STF group shows a significant advantage.

Spontaneous lumbar curve correction following selective thoracic fusion in adolescent idiopathic scoliosis

Spontaneous lumbar curve correction following selective thoracic fusion in adolescent idiopathic scoliosis

Relationship between Fusion Mass Shift and Postoperative Distal Adding-on in Lenke 1 Adolescent Idiopathic Scoliosis after Selective Thoracic Fusion.

This is a retrospective cohort study. This study aims to investigate the risk factors for postoperative distal adding-on in Lenke 1 adolescent idiopathic scoliosis (AIS) and validate the relationship between fusion mass shift (FMS) and postoperative distal adding-on. Postoperative distal curve adding-on is one of the complications in AIS. FMS has been proposed to prevent postoperative distal adding-on, which requires further validation from different institutions. This study included 60 patients with Lenke 1 AIS who underwent selective thoracic fusion surgery. Coronal spinal alignment parameters were analyzed preoperatively, postoperatively, and at the final follow-up. The postoperative FMS was divided into two groups: the balanced group (FMS ≤20 mm) and the unbalanced group (FMS >20 mm). An independent t-test was used to compare quantitative data between groups, and a chi-square test was used for qualitative data. Furthermore, binary logistic regression and receiver operating characteristics curve analyses were used to identify the risk factors for postoperative distal adding-on in AIS. At 2-year follow-up, the unbalanced group was more likely to have adding-on (17 of 24 patients) than the balanced group (six of 36 patients; p<0.001). Twenty-three patients with distal adding-on had significantly greater preoperative and postoperative lower instrumented vertebrae (LIV) rotation, FMS, and FMS angle (FMSA) than those without postoperative distal adding-on. Binary logistic regression analysis selected three independent risk factors for adding-on incidence after surgery: FMS (odds ratio [OR], 1.115; 95% confidence interval [CI], 1.049-1.185; p<0.001), FMSA (OR, 1.590; 95% CI, 1.225-2.064; p<0.001), and postoperative LIV rotation (OR, 6.581; 95% CI, 2.280-19.000; p<0.001). Achieving a balanced fusion mass intraoperatively is important to avoid postoperative distal adding-on, with FMS of <20 mm and FMS angle of <4.5°. Furthermore, correcting LIV rotation helps to decrease the incidence of postoperative distal addingon.

Satisfactory immediate spontaneous correction may not mean satisfactory final results for moderate TL/L curves after selective thoracic fusion in AIS patients

BackgroundFew studies have focused on the chronic spontaneous behavior of the unfused TL/L curve during follow-up. The purpose of the present study was to explore the behavior of the unfused TL/L curve during a long-term follow-up to identify the risk factors for correction loss.MethodsSixty-four age-matched female AIS patients undergoing selective thoracic fusion were enrolled. Patients were divided into 2 groups according to whether there was correction loss. Risk factors for correction loss of the unfused TL/L curves were analyzed. The relationship and difference between the immediate postoperative thoracic and TL/L Cobb angles were explored.ResultsThe TL/L Cobb angle was 28.17° before surgery, 8.60° after surgery, and 10.74° at the final follow-up, with a correction loss of 2.14°. Each subgroup contained 32 cases. A smaller postoperative TL/L Cobb angle was the only risk factor that was independently associated with TL/L correction loss. In the LOSS group, there was a significant difference and no correlation between the immediate postoperative TL/L and the thoracic Cobb angle. In the NO-LOSS group, there was a moderate correlation and no difference between them.ConclusionA smaller immediate postoperative TL/L Cobb angle may have been associated with TL/L correction loss during the long-term follow-up. Thus, good immediate postoperative spontaneous correction may not mean a satisfactory outcome at the final follow-up after STF. Mismatch between thoracic and TL/L Cobb angles immediately after surgery may also be related to correction loss of the unfused TL/L curves. Close attention should be paid in case of deterioration.

Long-term Radiographic and Clinical Outcomes After Selective Thoracic Fusion for Adolescent Idiopathic Scoliosis With Lenke 1C Curve.

Despite the promising results with selective thoracic fusion (STF) in patients with adolescent idiopathic scoliosis (AIS) of the Lenke 1C curve, postoperative coronal imbalance and progression of the unfused lumbar curve have been concerns in long-term follow-up. In this study, we aimed to investigate the radiographic and clinical outcomes after STF for AIS with Lenke 1C curve with long-term follow-up. A total of 30 patients with AIS with Lenke 1C curves who underwent STF between 2005 and 2017 were included. Minimum follow-up duration was 5 years. Time-dependent changes in radiographic parameters were investigated preoperatively, immediately postoperatively, and at the last follow-up. In addition, radiographic adverse events such as coronal decompensation (CD), lumbar decompensation (LD), distal adding-on (DA) phenomenon, and trunk shift were evaluated at the last follow-up. The Scoliosis Research Society-22 score was used for clinical outcome evaluation. The mean age at the time of surgery was 13.8 years. The mean follow-up duration was 6.7 ± 0.8 years. The main thoracic curve significantly improved from 57 degrees to 23 degrees (60% correction), and the thoracolumbar/lumbar curve significantly improved from 47 degrees to 28 degrees (41% correction). Coronal balance was 15 mm after surgery but significantly improved to 10 mm at the last follow-up ( P = 0.033). At the final follow-up, 11 patients (37%) sustained at least one of the radiographic adverse events: CD in 5 patients (17%), LD in 3 (10%), DA in 4 (13%), and trunk shift in 3 (10.%). However, there were no cases requiring revision surgery. In addition, there were no significant differences in any items or total Scoliosis Research Society-22 score between the patients with and without radiographic adverse events. STF in Lenke 1C curves showed an acceptable risk of adverse radiographic events such as CD, LD, DA, and trunk shift in long-term follow-up. We suggest that STF without fusion to the thoracolumbar/lumbar curve would be sufficient in treating AIS with Lenke 1C curve. Level III.

Optimal lowest instrumented vertebra selection with consideration of coronal and sagittal planes to prevent distal junctional complications in patients with Lenke type 1A and 2A adolescent idiopathic scoliosis.

Postoperative distal adding-on and distal junctional kyphosis are major distal junctional complications after selective thoracic fusion in patients with adolescent idiopathic scoliosis (AIS). This study aimed to investigate the incidence of distal adding-on and distal junctional kyphosis and evaluate the validity of our selection criteria for the lowest instrumented vertebra (LIV) in patients with Lenke type 1A and 2A AIS. We retrospectively analyzed the data of patients with Lenke type 1A and 2A AIS, who underwent posterior fusion surgery. LIV selection included the followings: (1) stable vertebra on traction film, (2) disc space neutralization below the LIV on the side-bending film, and (3) lordotic disc below the LIV on the lateral film. Radiographic parameters and the revised 22-item Scoliosis Research Society Questionnaire (SRS-22r) were evaluated. The incidence of postoperative distal adding-on and distal junctional kyphosis was also investigated. Ninety patients (83 women and 7 men; 64 with type 1A and 26 with type 2A) were included. After the operation, each curve and the SRS-22r of self-image, mental health, and subtotal domains were significantly improved. Distal adding-on occurred in three patients (3.3%, one in type 1A and two in type 2A) at 2years postoperatively. No patients exhibited distal junctional kyphosis. Our LIV selection criteria could reduce the incidence of postoperative distal adding-on and distal junctional kyphosis in patients with Lenke type 1A and 2A AIS. Level IV.

Do Preoperative Supine Radiographs Predict Postoperative Residual Lumbar Curvatures in Adolescent Idiopathic Scoliosis? A Retrospective Cohort Study.

Retrospective comparative study. This study compares supine vs bending flexibility radiographs and evaluates their ability to predict residual postoperative lumbar curvature after selective thoracic fusion for Lenke 1 and 2 curves across different lumbar modifiers (A, B, and C) in adolescent idiopathic scoliosis (AIS). This was a retrospective review of AIS Lenke 1 and 2 patients who underwent posterior fusion. All patients had preoperative flexibility radiographs including side-bending and supine posteroanterior (PA) films, in addition to pre- and post-operative standing PA and lateral radiographs. We used SurgiMap 2.0 software for all radiographic measurements. Pearson correlations and linear regression models were developed in SAS. A total of 86 patients were included mean age 14.9years and follow-up 72.3 months. Preoperative supine lumbar Cobb angle and preoperative side-bending Cobb angles had similar, positive correlations with postoperative lumbar Cobb angle, r = .55 (P < .001) and r = .54 (P < .001), respectively. Three regression models were built to predict postoperative lumbar Cobb angles from preoperative information: Model S (R2 = .39) uses preoperative supine lumbar curve; Model B (R2 = .44) uses preoperative side-bending lumbar curve; Model SB (R2 = .49) uses both preoperative supine and side-bending lumbar curves. Model S and B performed just as well as Model SB. Either supine or side-bending radiographs alone may be used to estimate mean residual postoperative lumbar curvature after selective posterior thoracic fusion, but little is to be gained by taking both supine and side-bending radiographs.

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.

The Use of High-Density Pedicle Screw Construct with Direct Vertebral Derotation of the Lowest Instrumented Vertebra in Selective Thoracic Fusion for Adolescent Idiopathic Scoliosis: Comparison of Two Surgical Strategies.

This study was a retrospective case series. This study was designed to determine whether direct vertebral rotation (DVR) of the lowest instrumented vertebra (LIV) using a high-density (HD) construct can reduce fusion segments without increasing adverse outcomes in selective thoracic fusion (STF) for adolescent idiopathic scoliosis (AIS). LIV DVR is used to maximize spontaneous lumbar curve correction and reduce adverse outcomes during STF for AIS. However, evidence is limited on whether LIV DVR can allow a proximally located LIV and reduce fusion segments without increasing adverse outcomes. We reviewed consecutive patients with Lenke 1 AIS who underwent STF from 2000 to 2017. The patients were divided into two groups based on the surgical strategy used: low-density (LD) construct without DVR of the LIV (LD group) versus HD construct with DVR of the LIV (HD group). We collected data on the patient's demographic characteristics, skeletal maturity, operative data, and measured radiological parameters in the preoperative and final follow-up radiographs. The occurrence of adding-on (AO) and coronal decompensation was also determined. In this study, 72 patients (five males and 67 females) with a mean age of 14.1±2.3 years were included. No significant differences in the demographics, skeletal maturity, and Lenke type distribution were observed between the two groups; however, the follow-up duration was significantly longer in the LD group (64.3±25.7 months vs. 40.7±22.2 months, p <0.001). The HD group had significantly shorter fusion segments (7.1±1.3 vs. 8.5±1.2, p <0.001) and a more proximal LIV level (12.1±0.9 vs. 12.7±1.0, p =0.009). In the radiological measurements, the improvement of LIV+1 rotation (Nash-Moe scale) was significantly larger in the HD group (0.53±0.51 vs. 0.21±0.41, p =0.008). AO and decompensation occurred in 7 (9.7%) and 4 (5.6%) patients in the HD and LD groups, respectively, without any significant difference between the two groups. In this study, the HD group had a significantly shorter fusion level and a more proximal LIV than the LD group; however, the two groups had similar curve correction and adverse radiological outcome rates.

Is Lenke Rule About Selective Thoracic Fusion Applicable for Younger Adult Idiopathic Scoliosis Under 40 Years of Age: Comparison With Adolescent Patients.

Retrospective study. To evaluate the surgical outcomes of younger adult idiopathic scoliosis patients (YAdIS) with selective thoracic fusion by comparing them with adolescent idiopathic scoliosis (AIS). Seventy-two idiopathic scoliosis patients (36 adults and 36 adolescents) treated by posterior-only all-pedicle screw technique were retrospective reviewed and matched by fusion levels. Radiographic parameters were evaluated preoperatively, postoperatively, and at final follow-up. Operating time, blood loss, transfusion, and complications were noted. The clinical outcome was assessed by the Scoliosis Research Society-22 questionnaire (SRS-22). The major thoracic curves in YAdIS and AIS groups were 56.3° ± 9.7°, 53.3° ± 10.1° and corrected to 17.2° ± 7.3°, 14.9° ± 7.5° respectively without significant difference in correction rate (69.3% vs 72.0%). For the lumbar curve, Cobb angles in 2 groups were 35.6° ± 10.1°and 31.4 ± 9.2° preoperatively, and were spontaneously corrected to 18.5° ± 9.0° and 12.6° ± 8.2°.Correction rates were 48.0% and 59.8% (P < .05). Preoperative and postoperative coronal vertebra alignments (CVA) in the YAdIS group were 20.6 ± 9.7mm and 16.8 ± 7.9mm (P > .05), while in the AIS group was 17.8 ± 10.5mm and 9.7 ± 8.3mm (P < .05). However, sagittal parameters showed significant improvements in thoracic kyphosis in both groups (P < .05). Complication rates were 25% vs 11.1% (P = .13) with no significant difference. Preoperative SRS-22 was worse in the YAdIS group than AIS group. All the scores were significantly improved postoperatively in the YAdIS group. However, in the AIS group, only SRS scores improved significantly. YAdIS can also be treated very well with selective thoracic fusion based on the Lenke rule used for AIS.

Curve Overcorrection Predicts Coronal Imbalance in Selective Thoracic Fusion in Adolescent Idiopathic Scoliosis.

Retrospective cohort Study. To identify predictive factors for coronal imbalance after selective fusion in adolescent idiopathic scoliosis (AIS) with Lenke type 1 curves. AIS patients with Lenke type 1 curve with A, B and C lumbar modifiers underwent selective thoracic fusion. The curve fulcrum flexibility and fulcrum bending correction index (FBCI) was studied. Coronal imbalance was defined as more than 2cm of truncal shift or more than 2cm list at two-year follow-up. A total of 301 patients were included in the study. Coronal imbalance at two-year follow-up was found in 38 patients (13%). At the preoperative stage, we found a significant difference in main curve flexibility with 66±15% in the balanced group and 60±15% in the imbalanced group (P = .032). At the immediate postoperative stage, mean curve correction was 71±13% vs 70±13% and mean FBCI was 112±29% vs 122±29% in the balance and unbalanced group, respectively (P = .031). Postoperative FBCI of more than 125% (third quartile) resulted in an odds ratio of 2.1 (95%CI:1.1-4.3) for coronal imbalance at two years (P=.031). No significant changes in fusion mass or LIV tilt was observed. A decreased preoperative flexibility and a higher FBCI was significantly associated with coronal imbalance. A high FBCI is an indication of a curve correction that exceeds the inherent flexibility of the spine, and our results add to a growing body of evidence that "overcorrection" of the main curve can lead to postoperative imbalance.

The Importance of Lumbar Curve Flexibility and Apical Vertebral Rotation for the Prediction of Spontaneous Lumbar Curve Correction in Selective Thoracic Fusion for Lenke Type 1 and 2 C Curves: Retrospective Cohort Study with a Mean Follow-Up of More than 10 years

Study DesignRetrospective analysis of a prospectively collected data.ObjectiveLumbar flexibility(LF) is generally defined with preoperative side bending films;it is not clear what percentage of LF predicts the spontaneous lumbar curve correction (SLCC) at long term follow up. Aim of this study was to find out cut-off value of preoperative LF,apical vertebra rotation(AVR) and apical vertebral translation(AVT);which may predict more than 50%SLCC.MethodsPatients with Lenke 1C&2C curves,treated with posterior STF,with a minimum 10 years follow up were included.The patients who had more than 50% SLCC(Group A) or less than 50% (Group B) were compared in terms of LF,AVR and AVT to understand a cut-off value of those parameters.Statistically, Receiver Operating Characteristic(ROC) test was used.ResultsFifty five AIS patients (54F, 1M) with mean age 14 (11-17) were included to study.Thoracic curve correction rate was 75%;lumbar curve correction rate was 59% at the latest follow up.Group A included 45(82%) patients at the latest follow up.Three patients (5%) showed coronal decompensation at early postop and 2 of them became compensated at f/up.ROC analyses showed 69% flexibility as the cut-off value for SLCC (P < .01).The difference between groups in terms of preop mean AVRs was significant (P = .029) (Group A = 1.9; Group B = 2.4).ConclusionIn Lenke 1C&2C curves,whenever LF on the preoperative bending x-ray is greater than 70% (P < .01)and AVR is equal or less than grade 2,STF provides satisfactory clinical and radiological SLCC with more than mean 10 years f/up.This flexibility rate and apical vertebral rotation can be helpful in decision making for successful STF.

Is it Safe to Save Levels and Choose the Lowest Instrumented Vertebra as Touched Vertebra While Selectively Fusing Lenke 1/2 Curves? A Proportional Meta-Analysis of Existing Evidence.

Meta-analysis. To compare the clinical and radiological outcomes in patients with Adolescent Idiopathic scoliosis (AIS) treated by selective thoracic fusion (STF) with lowest instrumented vertebra (LIV) at touched vertebra (TV) vs stable vertebra (SV). The databases PubMed, Embase and Google Scholar were searched until November 2020.Studies which had Lenke type 1 curves and Lenke type 2 curves in adolescent population treated by STF and which reported pre- and post-operative curve characteristics including correction percentage and complications were included. Studies which did not report the LIV selection, curve correction percentages and whose full text could not be acquired were excluded. Eight studies were included for analysis of which seven were found to be retrospective studies (level III evidence) and one was prospective study (level II evidence) each. Overall proportional meta-analysis found no significant difference in correction rate, total srs-22 scores, and complication rates. The evaluation of SV group and TV group as LIV for selective thoracic fusions in AIS reveals a comparable outcome in terms of curve correction, patient satisfaction scores and complication rates. The TV can be chosen safely as the LIV especially in type A and B Lenke 1&2 curves, as it saves more motion segments when compared to SV.

Preoperative factors associated with optimal outcomes of selective thoracic fusion at 5years.

Prior work identified optimal outcomes at 2years following selective thoracic fusion (STF) for adolescent idiopathic scoliosis (AIS) but it is unclear whether these published predictors represent what is required to achieve an optimal outcome with further time and potential growth. The purpose of this study was to determine the preoperative factors associated with optimal outcome of STF for AIS at 5years. Patients with primary thoracic AIS (Lenke 1-4C curves) who underwent a STF and had minimum 5years of follow-up were included. Optimal postoperative outcomes for a STF included a deformity-flexibility quotient (DFQ) < 4, lumbar curve < 26°, lumbar correction > 37%, C7-CSVL < 2cm, lumbar prominence < 5°, and trunk shift < 1.5cm. These outcomes were used to determine whether adhering to published recommendations for STF increased the likelihood of obtaining an optimal outcome at 5years, which included: preoperative lumbar curve < 45°, lumbar bend < 25°, apical vertebral translation ratio > 1.2, and thoracic/thoracolumbar Cobb ratio > 1.2. 127 patients met inclusion. A preoperative lumbar curve < 45° was associated with an increased likelihood of achieving three of the optimal outcomes: DFQ < 4, lumbar curve < 26°, and lumbar prominence < 5°. Following the 25° bend rule resulted in two optimal outcomes, while Cobb ratio > 1.2 was only associated with one optimal outcome. AVT > 1.2 was not significantly associated with any optimal outcome measures. This study found that at 5years, performing a STF when there is a preoperative lumbar Cobb < 45° remained the best guideline for increasing the likelihood of an optimal outcome.

Subjective perception of spinal deformity after selective versus non-selective fusion of Lenke 1C curves

PurposeTo assess the self-image perception and the Quality-of-Life (QoL) in female adolescents, with Lenke 1C scoliosis curves, treated with selective versus non-selective posterior spinal instrumentation and fusion (PSF).MethodsPatients undergoing PSF for idiopathic adolescent scoliosis (AIS) were recruited and divided into two groups: patients managed with selective thoracic fusion (STF) were included in Group A, whereas patients treated with non-selective fusion (N-STF) in Group B. Each patient completed the Italian version of the Scoliosis Research Society-22R questionnaire (SRS-22R), the Quality-of-Life Profile for Spinal Deformities questionnaire (QLPSD) and the Spinal Appearance Questionnaire (SAQ), before surgery and at 24-month follow-up.ResultsOne hundred and fifty seven female patients (mean age 16.38) were included in this study. 80 patients underwent STF, while 77 patients received N-STF. At 24-month follow-up, patients managed with N-STF showed better SRS-22R self-image mean score (p = .012), SRS-22R satisfaction mean score (p = .033), QLPSD body image mean score (p = .005), but worse SRS-22 function mean score (p = .006) and QLPSD back flexibility mean score (p = .007), compared with patients who underwent STF. In terms of self-image perception, patients undergoing STF showed significantly worse SAQ total mean score (p = .002), SAQ appearance mean score (p = .001) and SAQ expectation (p = .001). We found a significant correlation between SAQ appearance mean score and SRS-22R self-image (R = − 0.721), SRS-22 mental health (R = − 0.8), QLPSD psychosocial functioning (R = 0.7) and QLPSD back flexibility (R = 0.8).ConclusionAlthough the STF of Lenke 1C curves provides better functional outcomes, in the present study, female patients receiving STF revealed a worse perceived body image, compared with patients treated with N-STF, at 24-month follow-up. Particular attention should be addressed to the preoperative patient’s mental health and body image perception, when choosing between STF and N-STF.