Double Thoracic Curve Research Articles

Flexibility-tilt agreement best predicts shoulder balance following posterior spine fusion for adolescent idiopathic scoliosis.

We propose a novel concept, called flexibility-tilt agreement (FTA), which could be applied intra-operatively to improve shoulder balance following posterior spine fusion for Adolescent Idiopathic Scoliosis (AIS). We retrospectively applied this concept to a cohort with thoracic-only curves, seeking to: (1) evaluate the impact of FTA and other peri-operative variables on post-operative shoulder balance, and (2) evaluate deformity characteristics associated with achieving FTA. A single-institution registry was queried for patients undergoing PSF from 2000 to 2017 with main thoracic and double thoracic curves with at least 2-year follow-up. Flexibility was defined as the Cobb angle of the unfused proximal thoracic curve (cephalad to chosen UIV) on pre-operative bender. Tilt refers to post-operative UIV tilt angle. FTA means these values cancel (Flexibility + Tilt = 0 ± 5°). Logistic regression was performed to determine the association between peri-operative variables and shoulder balance. One hundred and sixty-one patients were included, mean age 13.6years old, and 47-month mean follow-up. FTA was achieved in 74 (46%) patients and was associated with post-operative (OR = 4.59) and final (OR = 6.98) medial shoulder balance with a threshold of 6° (AUC = 0.77, p = 0.038). FTA was the best predictor of shoulder balance of all tested variables. Patients that showed flexibility-tilt agreement, or FTA, had vastly increased odds of medial and lateral shoulder balance at a minimum of 2-year follow-up for all thoracic curves. Future studies can evaluate whether applying FTA to determine intra-operative corrective maneuvers prospectively leads to improvements in shoulder balance. Level III-retrospective comparative study.

Increased risk of thoracic hypokyphosis after posterior spinal correction and fusion in adolescent idiopathic scoliosis with thoracic double curve

Adolescent idiopathic scoliosis (AIS) is often associated with thoracic hypokyphosis or even lordosis. To analyze the influence of posterior correction and fusion in thoracic, structurally double-curved AIS. Out of 127 thoracic AIS (Lenke types1 and2) recorded prospectively, idiopathic double thoracic curve AIS were analyzed retrospectively. Surgery 2010-2019 with pedicle screw double rod systems in ascoliosis center. Follow-up (FU) at least 2years. Frontal and sagittal angles (whole-spine radiographs, 2planes): thoracic curve (MK), proximal-thoracic curve (PK) and lumbar curve (LK), thoracic kyphosis (TK), lumbar lordosis (LL). values as MW ± SD, students t‑test (significance a = 0.05), Pearson's correlation, sub-analysis with sagittal modifiers (-, N, +). Atotal of 47AIS-double thoracic curve were identified, mean FU 29.3 ± 12.2months, mean age 14 ± 1.5years. The mean correction (FU-preop) of MK was 67%, PK 53%, LK 73%, each significant, (p < 0.05). On average, TK (FU-preop) decreased by -6.5 ± 11.6° (p < 0.05), no significant change from FU (p = 0.6). TK (FU-preop) increased by 8.6 ± 5.0° (p < 0.05) in hypokyphotic cases, significantly decreased by -4.8 ± 9.6° in normokyphotic AIS and -25.3 ± 11.1° in hyperkyphotic cases, respectively (p < 0.05). In hypokyphosis: moderately strong correlation between correction PK (r = -0.5) and spontaneous correction LK (r = 0.8) (frontal plane) and change from pre- to postop TK (sagittal plane) (p < 0.05). Moderate correlation for hyperkyphosis: correction PK (r = -0.5) and postop TK (p < 0.05). No relevant correlations for normokyphosis. 17% had postop hypokyphosis, of which 0% had preop hypokyphosis. Rod diameter (5.5 mm vs. 6 mm) had no significant effect on TC. Posterior instrumented correction and fusion (pedicle screw dual rod systems) can significantly correct both lateral curves in idiopathic double thoracic curves, although it is associated with an increased risk of postop thoracic hypokyphosis, especially in preoperatively normokyphotic patients.

Assessment of Neck Imbalance in Adolescent Idiopathic Scoliosis Patients: A Cross-Section Study Based on Body Image of 115 Patients with Main or Double Thoracic Curve.

Neck imbalance negatively affects body aesthetics of adolescent idiopathic scoliosis (AIS) patients. The evaluation of neck imbalance is currently limited to radiographic parameters, but lacks visual indicators. Therefore, the purpose of this study was to establish indexes of neck imbalance based on body image and to investigate whether these indexes can truly reflect neck imbalance in AIS patients. We performed a cross-sectional study at a single institution between June 2017 and September 2020 and there were 115 subjects involved in this research. All patients were diagnosed with adolescent idiopathic scoliosis, Lenke type I/II. Radiographic parameters measured included cervical axis tilt (CAT), T1 tilt, first rib angle (FRA), clavicle angle (CA), radiographic shoulder height (RSH), proximal thoracic curve (PTC), apical vertebra translation of proximal thoracic (AVT of PT), main thoracic curve (MTC), apical vertebra translation of main thoracic (AVT of MT) and coronal balance (CB/C7PL-CSVL). Neck imbalance indexes were obtained and measured following a standardized manner. Intra-class correlation coefficient (ICC) analysis was performed for neck imbalance indexes to determine their intra-observer and inter-observer reliability, and correlation tests were performed for neck imbalance indexes with the radiographic parameters mentioned above. Strong intraobserver and interobserver reliability were observed in neck imbalance index (NII) 1 (0.91 and 0.88), neck imbalance index 2 (0.85 and 0.81) and NII 3 (0.82 and 0.80), P < 0.05. Significant correlation was found in cervical axis tilt (R=0.81 for NII 1, R=0.77 for NII 2 and R=0.78 for NII 3), T1 tilt (R=0.43 for NII 1, R=0.52 for NII 2 and R=0.48 for NII 3), first rib angle (R=0.41 for NII 1, R=0.48 for NII 2 and R=0.43 for NII 3), proximal thoracic curve (R=0.36 for NII 2) and apical vertebra translation of proximal thoracic (R=-0.37 for NII 2 and R=-0.35 for NII 3) with neck imbalance indexes. Neck imbalance index 1 showed the highest correlation with cervical axis tilt (R=0.81, P < 0.01). Neck imbalance indexes established in our study were in good correlation with cervical axis tilt (CAT), At the meantime, they showed significant correlations with T1 tilt and first rib angle (FRA). Our study provides a practical method for measurement of neck imbalance regarding realistic perspective and makes up for the lack of photographic indexes about neck imbalance.

Thoracic Curve Correction Ratio: An Objective Measure to Guide against Overcorrection of a Main Thoracic Curve in the Setting of a Structural Proximal Thoracic Curve.

Purpose: The correction of double thoracic (Lenke 2) curves has been associated with higher rates of postoperative shoulder imbalance that may compromise long-term outcomes following spinal deformity correction. A number of methods have been proposed to mitigate this risk, though no accepted standard measurement exists. The purpose of this study is to validate a novel quantitative method of determining the relative curve correction magnitude in double thoracic curves. Methods: Retrospective data from a multi-center database of patients undergoing surgical correction of left-proximal thoracic, right-main thoracic Lenke 2 curves were analyzed. A novel measurement tool, the Thoracic Curve Correction Ratio (TCCR), was applied for the purposes of validation against historical data. Results: A total of 305 patients with complete two-year follow-up data were included. The TCCR, or the ratio of postoperative percent correction of the thoracic curves divided by the ratio of the preoperative curve magnitudes, displayed a significant negative correlation (Pearson R = −0.66; p < 0.001) with T1 tilt at two years postoperatively. Conclusions: The TCCR could be added as an important factor in the preoperative planning process and intraoperative assessment in order to reduce postoperative T1 tilt. While T1 tilt remains an imperfect surrogate measure for clinical shoulder balance, it serves as one of many potential measures that the surgeon may evaluate quantitatively and radiographically.

Fate of Thoracic Curves in Adolescent Idiopathic Scoliosis after Selective Thoracic Fusion: Systematic Review of Literature and Meta-Analysis

Background Data: In adolescent idiopathic scoliosis (AIS), the upper thoracic spine (T1–T5) may represent an additional curve called the proximal thoracic curve (PTC), which is nearly equal and opposite to the main thoracic curve (MTC); this is a classic example of a ‘‘double thoracic curve pattern.” So, after selective thoracic fusion (STF) for MTC by either anterior or posterior instrumentation and fusion, what happens to the noninstrumented PTC and instrumented MTC? Study Design: Systematic review of literature and meta-analysis. Purpose: To evaluate the fate of the noninstrumented PTC and instrumented MTC after STF for the MTC by either anterior or posterior instrumentation and fusion. Methods: This study was conducted by searching the PubMed and Cochrane databases and included patients with AIS treated by STF between 1999 and 2020. The type of approach, degree of correction achieved in MTC, PTC, and apical vertebral rotation (AVR), and complications rate were reported independently by two authors. Results: Our systematic review yielded 1686 patients, with 18 studies meeting the required criteria. MTC has been corrected by 24.89 ± 8.45 degrees, while PTC has been corrected by 14.94 ± 7.18 degrees. Cobb’s angle was reported in seven studies for MTC angle and four studies for lumbar and thoracolumbar curves angle and has been corrected by 19.68 ± 6.55 degrees. Moreover, shoulder tilt has been corrected by 0.83 ± 0.83. Data for correction of AVR was reported in two studies and has been corrected by 15.95 ± 4.65 degrees. Conclusion: Anterior and posterior spinal fusion had no statistical significance difference regarding MTC, shoulder tilt, and AVRcorrection. However, PTC corrections was more significant after anterior spinal fusion (ASF) than posterior spinal fusion (PSF). (2021ESJ228)

Risk factors for the presence of syringomyelia in idiopathic scoliosis: analysis of 3,285 cases and brief literature review

Objective. To analyze possible radiological and clinical risk factors for syringomyelia in patients with scoliotic deformity. Material and Methods. An analysis of data from 3,285 patients with idiopathic scoliosis treated from 1997 to 2020 was performed. Syringomyelia was detected in 38 (1.16 %) cases. In 26 cases, syringomyelia was combined with Chiari malformation. In order to search for information on the topic under discussion, the international databases (Scopus, Medline, and GoogleScholar) were used. Additional search for publications listed in the article references was carried out. According to the literature data, possible risk factors for the presence of syringomyelia have been identified. Results. Among patients with confirmed syringomyelia, a left-sided thoracic scoliotic curve was found in 23.7 % of cases, a double thoracic curve in 18.4 %, an upper thoracic scoliotic curve in 7.9 %, an increase in thoracic kyphosis in 60.5 %, and initial neurological deficit in 47.4 %, which is significantly higher than the same indicators in the entire group of patients. The ratio of male and female patients in the entire group was 1.0 : 6.7, in the group with syringomyelia – 1.00 : 1.71. Conclusion. According to the literature review and statistically significant factors identified in the analysis of the monocentric group, it can be said that the left-sided thoracic scoliotic curve, upper thoracic curve, double thoracic curve, increased thoracic kyphosis, initial pyramidal insufficiency in the lower extremities, male sex, and a decrease in the initial somatosensory evoked potentials are risk factors for syringomyelia. If the above factors are present in a patient, the MRI study may be recommended to determine further treatment tactics. Before surgical correction of scoliotic deformity, MRI is recommended for all patients.

Selecting the "Touched Vertebra" as the Lowest Instrumented Vertebra in Patients with Lenke Type-1 and 2 Curves: Radiographic Results After a Minimum 5-Year Follow-up.

The selection of the lowest instrumented vertebra (LIV) in patients with adolescent idiopathic scoliosis (AIS) is still controversial. Although multiple radiographic methods have been proposed, there is no universally accepted guideline for appropriate selection of the LIV. We developed a simple and reproducible method for selection of the LIV in patients with Lenke type-1 (main thoracic) and 2 (double thoracic) curves and investigated its effectiveness in producing optimal positioning of the LIV at 5 years of follow-up. The radiographs for 299 patients with Lenke type-1 or 2 AIS curves that were included in a multicenter database were evaluated after a minimum duration of follow-up of 5 years. The "touched vertebra" (TV) was selected on preoperative radiographs by 2 independent examiners. The LIV on postoperative radiographs was compared with the preoperative TV. The final LIV position in relation to the center sacral vertical line (CSVL) was assessed. The CSVL-LIV distance and coronal balance in patients who had fusion to the TV were compared with those in patients who had fusion cephalad and caudad to the TV. The sagittal plane was also reviewed. In 86.6% of patients, the LIV was selected at or immediately adjacent to the TV. Among patients with an "A" lumbar modifier, those who had fusion cephalad to the TV had a significantly greater CSVL-LIV distance than those who had fusion to the TV (p = 0.006) or caudad to the TV (p = 0.002). In the groups with "B" (p = 0.424) and "C" (p = 0.326) lumbar modifiers, there were no differences among the TV groups. We recommend the TV rule as a third modifier in the Lenke AIS classification system. Selecting the TV as the LIV in patients with Lenke type-1 and 2 curves provides acceptable positioning of the LIV at long-term follow-up. The position of the LIV was not different when fusion was performed caudad to the TV but came at the expense of fewer motion segments. Patients with lumbar modifier "A" who had fusion cephalad to the TV had greater translation of the LIV, putting these patients at risk for poor long-term outcomes. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Intraoperative radiation exposure to patients in idiopathic scoliosis surgery with freehand insertion technique of pedicle screws and comparison to navigation techniques.

In surgical correction of scoliosis with pedicle screw dual-rod systems, frequently used freehand technique of screw positioning is challenging due to 3D deformity. Screw malposition can be associated with serious complications. Image-guided technologies are already available to improve accuracy of screw positioning and decrease radiation to surgeon. This study was conducted to measure intraoperative radiation to patients in freehand technique, evaluate screw-related complications and compare radiation values to published studies using navigation techniques. Retrospective analysis of prospectively collected data of 73 patients with idiopathic scoliosis, who underwent surgical correction with pedicle screw dual-rod system. Evaluated parameters were age, effective radiation dose (ED), fluoroscopy time, number of fused segments, correction and complications. Parameters were compared with regarding single thoracic curve (SC) and double thoracic and lumbar curves (DC), adolescent (10-18years) or adult (> 18years) idiopathic scoliosis, length of instrumentation. ED was compared with values for navigation from online database. Average age was 21.0 ± 9.7years, ED was 0.17 ± 0.1mSv, time of fluoroscopy was 24.1 ± 18.6s, 9.5 ± 1.9 fused segments. Average correction for SC was 75.7%, for DC 69.9% (thoracic) and 76.2% (lumbar). No screw-related complications. ED was significantly lower for SC versus DC (p < 0.01), short versus long fusions (p < 0.01), no significant difference for age (p = 0.1). Published navigation data showed 6.5- to 8.8-times higher radiation exposure for patients compared to our results. Compared to navigation procedures, freehanded positioning of pedicle screws in experienced hands is a safe and effective method for surgical correction of idiopathic scoliosis with a significant decrease in radiation exposure to patients.

Spinal Deformity in Sotos Syndrome: First Results of Growth-friendly Spine Surgery.

Sotos syndrome (SS), or cerebral gigantism, describes children with macrocephaly, craniofacial abnormalities, general overgrowth, ligamentous laxity, developmental delay, and neurological disabilities. Fewer than 500 cases have been reported since Sotos and colleagues described the condition in 1964 and no literature exists on the management of spinal deformity in children under 10 years old.The aims of this study were: (1) to characterize the presentation of spinal deformities in patients with SS; and (2) to provide preliminary results of growth-friendly instrumentation (GFI) in these children. Thirteen children (9 boys) with SS and minimum of 2-year follow-up were identified from 2 multicenter early-onset scoliosis (EOS) databases (1997-2017). Mean age at index surgery and follow-up duration were 5.0 years (range, 1.8 to 10 y) and 7.2 years (range, 2.1 to 14.9 y), respectively. Patients underwent GFI for a mean of 5.7 years (range, 2 to 10.2 y), with an average of 9 lengthenings (range, 2 to 18). Definitive spinal fusion was performed in 4 patients (31%). Major curve magnitude, T1-T12 and T1-S1 lengths, thoracic kyphosis, and lumbar lordosis were evaluated preindex, postindex, latest GFI, and postfusion, when possible. Five thoracolumbar (38%), 4 double major (31%), 2 main thoracic (15%), and 2 double thoracic curves (15%) were seen that spanned a mean of 6.8 levels (5 to 9). Major curves improved 36% (range, 5% to 71%), from a mean of 71 degrees (range, 48 to 90 degrees) to 46 degrees (range, 20 to 73 degrees) postindex surgery (P<0.001). Major curves remained stable at a mean of 52 degrees (range, 20 to 87 degrees) at latest GFI (P=0.36). True T1-T12 and T1-S1 growth velocities during GFI were 0.5 mm/mo (range, 0.4 to 0.8 mm/mo) and 0.8 mm/mo (range, 0.1 to 2.1 mm/mo), respectively. Twenty-six complications occurred in 9 patients (69%) averaging 2 complications per patient (range, 0 to 7). This is the first study to evaluate the outcomes of GFI in children with SS and EOS. Compared with published data for outcomes of GFI in EOS, children with SS may have less major curve correction. Growth-friendly surgery remains an effective treatment method for EOS in patients with SS. Level IV-retrospective case-series.

Scoliosis Correction Surgery for a Patient with Marfan Syndrome with Severe Scoliosis and Restricted Lung Ventilation

Objective: Marfan syndrome is a multi-system disease caused by genetic mutations that can cause damage to multiple systems in the body. With the development of the disease, the scoliosis of patients with Marfan syndrome will be further aggravated, which will eventually seriously affect the patient's cardiopulmonary function and lead to a serious decline in the patient's quality of life. The aim is to summarize the experience of spinal orthopedic surgery in a patient with Marfan syndrome and severe scoliosis with limited pulmonary ventilation. Method: In November 2019, a 13-year-old male with Marfan syndrome with severe scoliosis and restricted lung ventilation was admitted. The full-length positive and lateral X-rays of the spine before the operation showed that the spine was S-shaped scoliosis, double thoracic curve (thoracic curve + lumbar curve), upper vertebrae T4, lower vertebrae T11, thoracic T4-T11 structural curve, thoracic Cobb angle of bend is 42.4°, the lumbar bend is compensatory, Cobb angle of lumbar bend is 33.2° The lung function indicates that the forced end-expiratory volume/forced vital capacity (FEV1/FVC) in the first second is 70%. correction + interlaminar bone graft fusion + posterior T4-T11 pedicle screw was performed on the patient under general anesthesia with tracheal intubation. Result: The full-length positive and lateral X-rays of the spine at 1 week, 1 month, 3 months, and 1 year after surgery showed that the internal fixation position was good, and the Cobb angle remained basically unchanged. There was basically no change in the Cobb angle of the thoracic curve (10.2°, 10.8°, 10.9°, 10.5°, respectively) and the Cobb angle of the lumbar curve (13.1°, 13.6°, 13.8°, 13.9, respectively) at each follow-up time point after surgery. The lung function at 1 year after surgery suggested that FEV1/FVC was 80%. No sensorimotor abnormalities and other complications occurred during the follow-up. Conclusion: Scoliosis correction surgery is feasible and safe for patients with Marfan syndrome combined with severe scoliosis deformity and restricted lung ventilation. It can improve the patient's appearance, at the same time improve the patient's cardiopulmonary function, and solve the problem of the continued increase in the number of cobb angles of scoliosis. Surgery improves the quality of life of patients as a whole.

Does fusion to T2 compared with T3/T4 lead to improved shoulder balance in adolescent idiopathic scoliosis with a double thoracic curve?

Proximal fusion level selection in adolescent idiopathic scoliosis (AIS) with a double thoracic curve (Lenke-2) remains debatable. The aim of this study was to compare the radiological outcomes of corrective surgery for Lenke-2 AIS according to the upper instrumented vertebra (UIV). This study included 74 patients who underwent corrective surgery for Lenke-2 AIS with the right main thoracic and left proximal thoracic (PT) curve at a single center. Various radiological parameters were measured using whole-spine standing radiographs preoperatively and postoperatively. Patients were grouped by proximal fusion level: T2 (group F; fusion, N=15) or T3/T4 (group NF; nonfusion, N=59). Preoperative and postoperative radiological parameters were compared between the two groups. Group NF was divided on the basis of the existence of a postoperative shoulder imbalance (PSI; >15 mm) and a subgroup analysis was carried out. PT curve correction rate (58.5 vs. 46.3%, P=0.005), right shoulder depression (4.3 vs. 10.3 mm, P=0.020), and proximal adjacent wedging (1.1 vs. 3.5°, P<0.001) were different between groups F and NF postoperatively. In the subgroup analysis, the Risser grade (3.9 vs. 2.8, P=0.009) and the main thoracic curve flexibility (53.5 vs. 42.6%, P=0.038) were different between the PSI positive and the PSI negative group when T3 or T4 was chosen as the UIV in Lenke-2 AIS. If T2 is selected as the UIV in patients with Lenke-2 AIS, more PT curve correction, less right shoulder depression, and less adjacent disc wedging can be anticipated. If T3 or T4 is chosen as the UIV, then right shoulder depression can be a problem postoperatively. Greater skeletal maturity and higher flexibility of the main thoracic curve might be preoperative risk factors for PSI. Thus, extension of the proximal fusion to T2 can be considered if the patient shows greater skeletal maturation and more flexible main thoracic curve to prevent PSI in Lenke-2 AIS with the right main thoracic and left PT curve.

Is the routine use of magnetic resonance imaging indicated in patients with scoliosis?

To assess the reliability of the indicators for performing magnetic resonance imaging in patients with scoliosis and assess the incidence of neural axis anomalies in a population with scoliosis referred to a specialist centre. A retrospective review of magnetic resonance imaging (MRI) reports of all patients under the age of 18 who underwent a pre-operative MRI for investigation of their scoliosis between 2009 and 2014 at a single institution was performed. There were 851 patients who underwent an MRI scan of their whole spine with a mean age of 14.08 years. There were 211 males and 640 females. One hundred and fourteen neural axis abnormalities (NAA) were identified. The presence of a left sided thoracic curve, a double thoracic curve, being male nor being diagnosed before the age of 10 were found to be statistically significant for the presence of a NAA. Furthermore, 2.34% of patients were also found to have an incidental finding (IF) of an extraspinal abnormality. From our series, the reported indications for performing an MRI scan in the presence of scoliosis are not reliable for the presence of an underlying NAA. We have demonstrated that there is a number of intra and extra dural anomalies found on MRI without clinical symptoms and signs. This acts as normative information for this group. Scoliosis; magnetic resonance imaging (MRI); neural axis abnormalities (NAA); adolescent idiopathic scoliosis (AIS).

Classifications in Brief: The Lenke Classification for Adolescent Idiopathic Scoliosis.

Classifications in Brief: The Lenke Classification for Adolescent Idiopathic Scoliosis.

Cervical sagittal alignment in patients with adolescent idiopathic scoliosis: is it corrected by surgery?

OBJECTIVE Cervical sagittal alignment (CSA) is related to function and quality of life, but it has not been frequently studied in patients with adolescent idiopathic scoliosis. This study aimed to reveal the change in CSA following corrective surgery, compare the cervical sagittal parameters according to curve types, and assess related factors for postoperative aggravation of CSA. METHODS The authors studied 318 consecutive patients with adolescent idiopathic scoliosis who underwent corrective surgery at a single center. Occiput-C2 and C2-7 lordosis, C2-7 sagittal vertical axis (SVA), T-1 slope, thoracic kyphosis, and lumbar sagittal profiles were measured preoperatively and postoperatively. Scoliosis Research Society Outcomes Questionnaire (SRS-22) scores were used as clinical outcomes. Each radiological parameter was compared preoperatively and postoperatively according to curve types (double major, single thoracic, and double thoracic curves). Patients were grouped based on preoperative CSA: the lordotic group (group L) and the kyphotic group (group K). Each radiological parameter was compared between the groups. Related factors for postoperative aggravation of CSA were assessed using multivariate logistic analysis. RESULTS Of the total number of patients studied, 67.0% (213 of 318) and 54.4% (173 of 318) showed cervical kyphotic alignment preoperatively and postoperatively, respectively. C2-7 lordosis increased (from -5.8° to -1.1°; p < 0.001) and C2-7 SVA decreased (from 24.2 to 20.0 mm; p < 0.001) postoperatively regardless of curve types. Although group K showed improvement in C2-7 lordosis (from -12.7° to -4.8°; p < 0.001), group L showed no difference (from 9.0° to 6.9°; p = 0.115) postoperatively. Clinical outcomes were not related to the degree of cervical kyphosis in this cohort. C2-7 lordosis (p < 0.001) and pelvic tilt (p = 0.019) were related to postoperative aggravation of CSA. CONCLUSIONS Regardless of the trend of improvement in CSA, many patients (54.4%) still showed cervical kyphotic alignment postoperatively. C2-7 lordosis and C2-7 SVA improved postoperatively in all curve types. However, postoperative changes in C2-7 lordosis showed different results based on preoperative CSA, which could be related to T-1 slope and thoracic kyphosis. However, clinical outcomes showed no difference based on CSA in this study cohort. Greater C2-7 lordosis and proximal thoracic curve preoperatively were risk factors for postoperative aggravation of CSA (p < 0.001 and p = 0.019, respectively).

The mechanisms underlying the variety of preoperative directionalities of shoulder tilting in adolescent idiopathic scoliosis patients with double thoracic curve.

Preoperative directionality of shoulder tilting seems to be independent of the radiographic features of proximal thoracic (PT) curve in adolescent idiopathic scoliosis (AIS) patients. To date, no study had investigated the mechanisms underlying the variety of preoperative directionalities of shoulder tilting in AIS patients. The purpose of this study was to evaluate the differences of radiographic features between Lenke type 2 (double thoracic curve) AIS patients with different preoperative directionalities of shoulder tilting. A total of 130 Lenke type 2 AIS patients were included in this study and were divided into two groups according to the value of radiographic shoulder height (RSH). There were 78 cases (71 females and 7 males) with RSH less than 0cm in Group A and 52 cases (44 females and 8 males) with RSH equal to or more than 0cm in Group B. Preoperative standing anteroposterior X-ray films of the spine were obtained in all these subjects and were analyzed with respect to the following parameters: T1 tilt, PT Cobb angle, main thoracic (MT) Cobb angle, the apical level of PT curve, the apical level of MT curve, and RSH. These parameters were compared between these two groups and the correlations between RSH and the other parameters were analyzed in all of these subjects. No significant difference was found between these two groups with respect to PT Cobb angle or the apical level of PT curve (P>0.05). The apical level of MT curve was significantly more proximal in Group A compared with Group B (P<0.05). The MT Cobb angle was significantly larger in Group A compared with Group B (P<0.05). Both the T1 tilt and the PT Cobb angle/MT Cobb angle ratio in Group A were significantly smaller than those in Group B (P<0.05). The RSH was positively associated with T1 tilt, the apical level of MT curve, and the PT Cobb angle/MT Cobb angle ratio, but was negatively associated with MT Cobb angle (P<0.05). The directionality of shoulder tilting is diverse in Lenke type 2 AIS patients. The preoperative directionality of shoulder mainly depends on the profile of MT curve rather thanthat of PT curve. The RSH should be carefully evaluated before making a surgical plan in these patients.

Adolescent Scoliosis 1A001: Radiographic Results of Selecting the Touched Vertebra as the Lowest Instrumented Vertebra in Lenke Type 1 (Main Thoracic) & Type 2 (Double Thoracic) Curves at a Minimum 5-year Follow-up

Introduction:A prior study showed the touched vertebra (TV), defined as the most cephalad thoracolumbar/lumbar vertebra “touched” by the center sacral vertical line (CSVL), as a potential landmark vertebra & recommended lowest instrumented vertebra (LIV) as well. We evaluated a large cohort of Lenke type 1 & 2 cases to determine if selecting the TV as the LIV will produce optimal positioning at a min. 5 yrs postoperative. Our hypothesis was that it would and that fusing short of the TV would lead to a suboptimal result.Material and Methods:299 pts with Lenke 1 (n = 207) or Lenke 2 (n = 92) AIS curves at a min. 5 yr f/u were evaluated. The TV was selected on the preoperative x-ray by 2 independent examiners & confirmed for agreement. The LIV selected was compared to the preoperative TV as well as the LIV-CSVL distance at min. 5 yr f/u. Comparison was made on the LIV-CSVL distance in pts fused short of the TV, to the TV or distal to the TV using standard statistical software.Results:When comparing the entire cohort, differences in 5 yr LIV-CSVL absolute values between the 3 groups approached, but did not reach, significance ( = .055). In a subanalysis of the lumbar A modifiers (n = 161), main effect ANOVA indicated a significant difference among the 3 groups ( = .002). Post hoc comparison revealed that pts fused short of the TV (TV-1) had significantly greater LIV-CSVL distance values than those fused to the TV ( = .006) & those fused distal to the TV (TV+1, = .002). There was no significant difference among the 3 groups when looking at lumbar B (n = 76, p = 0.424) & lumbar C (n = 62, = .326) modifiers.Conclusion:Selecting the touched vertebra (TV) as the LIV for Lenke type 1A & 2A curves produced optimal LIV positioning at a minimum 5 yrs postoperative, while fusing short of the TV showed statistically increased LIV- CSVL translation. Understanding & utilizing the TV rule assists the surgeon in proper LIV selection in Lenke type 1A & 2A curve patterns for AIS.

Adolescent Scoliosis 1A001: Radiographic Results of Selecting the Touched Vertebra as the Lowest Instrumented Vertebra in Lenke Type 1 (Main Thoracic) & Type 2 (Double Thoracic) Curves at a Minimum 5-year Follow-up

Introduction:A prior study showed the touched vertebra (TV), defined as the most cephalad thoracolumbar/lumbar vertebra “touched” by the center sacral vertical line (CSVL), as a potential landmark vertebra & recommended lowest instrumented vertebra (LIV) as well. We evaluated a large cohort of Lenke type 1 & 2 cases to determine if selecting the TV as the LIV will produce optimal positioning at a min. 5 yrs postoperative. Our hypothesis was that it would and that fusing short of the TV would lead to a suboptimal result.Material and Methods:299 pts with Lenke 1 (n = 207) or Lenke 2 (n = 92) AIS curves at a min. 5 yr f/u were evaluated. The TV was selected on the preoperative x-ray by 2 independent examiners & confirmed for agreement. The LIV selected was compared to the preoperative TV as well as the LIV-CSVL distance at min. 5 yr f/u. Comparison was made on the LIV-CSVL distance in pts fused short of the TV, to the TV or distal to the TV using standard statistical software.Results:When comparing the entire cohort, differences in 5 yr LIV-CSVL absolute values between the 3 groups approached, but did not reach, significance (P = .055). In a subanalysis of the lumbar A modifiers (n = 161), main effect ANOVA indicated a significant difference among the 3 groups (P = .002). Post hoc comparison revealed that pts fused short of the TV (TV-1) had significantly greater LIV-CSVL distance values than those fused to the TV (P = .006) & those fused distal to the TV (TV+1, P = .002). There was no significant difference among the 3 groups when looking at lumbar B (n = 76, p = 0.424) & lumbar C (n = 62, P = .326) modifiers.Conclusion:Selecting the touched vertebra (TV) as the LIV for Lenke type 1A & 2A curves produced optimal LIV positioning at a minimum 5 yrs postoperative, while fusing short of the TV showed statistically increased LIV- CSVL translation. Understanding & utilizing the TV rule assists the surgeon in proper LIV selection in Lenke type 1A & 2A curve patterns for AIS.

Correction of Spinal Deformity on a Lung Transplantation Recipient

BackgroundThe coexistence of lung disease and scoliosis entails a dramatic situation. There are no papers reporting scoliosis surgery in patients who suffered lung transplantation. PurposeTo describe the case of a patient who underwent surgery to correct progressive spinal deformity after two consecutive lung transplants. Study DesignCase report, including review of patient records, imaging and pulmonary function tests, and literature review. MethodsA 9-year-old woman diagnosed of idiopathic pulmonary fibrosis and progressive scoliosis underwent lung transplant. Retransplantation of right lung was performed at the age of 14 due to chronic rejection. When she was 16, respiratory function was stable and spinal deformity severely impaired her quality of life. Patient and family demanded a surgical correction. At that moment, she had severe osteoporosis and immunosuppression as a result of anti-rejection therapy. The pattern was a severe double thoracic curve T1–T6 89° and T7–L1 139°. To correct it, a posterior instrumented spine fusion from T2 to L4 using a hybrid configuration was performed. ResultsNo significant complications occurred in perioperative, postoperative, and midterm follow-up periods. Solid fusion was achieved and patient was satisfied with surgery. Unfortunately, chronic lung graft rejection worsened her long-term general status. ConclusionsScoliosis surgery on lung transplant recipients is feasible, regardless of potential complications related to immunosuppression and osteoporosis. The goal is to improve quality of life.

A retrospective study to reveal factors associated with postoperative shoulder imbalance in patients with adolescent idiopathic scoliosis with double thoracic curve.

OBJECTIVE Postoperative shoulder imbalance (PSI) is a critical consideration after corrective surgery for a double thoracic curve (Lenke Type 2); however, the radiographic factors related to PSI remain unclear. The purpose of this study was to identify the radiographic factors related to PSI after corrective surgery for adolescent idiopathic scoliosis (AIS) in patients with a double thoracic curve. METHODS This study included 80 patients with Lenke Type 2 AIS who underwent corrective surgery. Patients were grouped according to the presence [PSI(+)] or absence [PSI(-)] of shoulder imbalance at the final follow-up examination (differences of 20, 15, and 10 mm were used). Various radiographic parameters, including the Cobb angle of the proximal and middle thoracic curves (PTC and MTC), radiographic shoulder height (RSH), clavicle angle, T-1 tilt, trunk shift, and proximal and distal wedge angles (PWA and DWA), were assessed before and after surgery and compared between groups. RESULTS Overall, postoperative RSH decreased with time in the PSI(-) group but not in the PSI(+) group. Statistical analyses revealed that the preoperative Risser grade (p = 0.048), postoperative PWA (p = 0.028), and postoperative PTC/MTC ratio (p = 0.011) correlated with PSI. Presence of the adding-on phenomenon was also correlated with PSI, although this result was not statistically significant (p = 0.089). CONCLUSIONS Postoperative shoulder imbalance is common after corrective surgery for Lenke Type 2 AIS and correlates with a higher Risser grade, a larger postoperative PWA, and a higher postoperative PTC/MTC ratio. Presence of the distal adding-on phenomenon is associated with an increased PSI trend, although this result was not statistically significant. However, preoperative factors other than the Risser grade that affect the development of PSI were not identified by the study. Additional studies are required to reveal the risk factors for the development of PSI.

The potential risk of left subclavian artery injury from excessively long thoracic pedicle screws placed in the proximal thoracic regions of Lenke type 2 adolescent idiopathic scoliosis patients and normal teenagers: an anatomical study.

The altered anatomic positions of important structures adjacent to the vertebrae in adolescent idiopathic scoliosis (AIS) patients have been comprehensively investigated by previous radiographic studies. However, no study has evaluated the altered position of left subclavian artery (SA) in these patients. The purpose of this study is to evaluate the altered position of left subclavian artery in AIS patients with a double thoracic curve pattern. Nineteen Lenke type 2 AIS patients and thirteen normal teenagers were included in this study. Axial computed tomography images at T2 and T3 levels were obtained in all these subjects to evaluate the subclavian artery-vertebral angle (SAVA, defined as 0° when the artery was located directly lateral to the left and 180° when directly lateral to the right) and subclavian artery-vertebral distance (SAVD, the shortest distance between the artery and vertebral body). The percentage of left subclavian arteries at potential risk of injury from excessively long pedicle screws was calculated. The SAVA was significantly larger in AIS patients than that in normal teenagers at both T2 and T3 levels (P<0.05) while the SAVD was significantly smaller in AIS patients compared with normal teenagers at both T2 and T3 levels (P<0.05). The left SA was at potential risk of injury from excessively long left pedicle screws in 6 (31.6%) AIS patients at T2 level and in 10 (52.6%) patients at T3 level. The patients with risk of left SA injury had larger proximal thoracic (PT) and larger AVT of PT curve when compared with those without. No left SA was at potential risk of injury from excessively long left pedicle screws in normal teenagers. The left SA is located much closer to the vertebrae in the proximal thoracic curve of Lenke type 2 AIS patients when compared with normal teenagers. The spine surgeons should be aware of such altered position of left SA and choose appropriate pedicle length to avoid anterior cortical penetration in Lenke type 2 AIS patients.