T1 Tilt Angle Research Articles

Incidence of and Factors Associated with Spontaneous Correction of Postoperative Shoulder Imbalance in Adolescent Idiopathic Scoliosis Patients: A Retrospective Cohort Study

Abstract Background As far as we know, no study has investigated spontaneous postoperative shoulder imbalance (PSI) correction in adolescent idiopathic scoliosis (AIS) patients. The objective is to assess the incidence of and associated factors for spontaneous PSI correction in AIS patients. Methods The study evaluated 144 postoperative AIS patients with PSI aged 10–20 years between 2010 and 2018. An analysis included demographic data and radiographic measurements (Risser grading, Lenke type, upper instrumented vertebra [UIV], and lowest instrumented vertebra [LIV]). Preoperative, postoperative, and follow-up radiographs were evaluated for shoulder parameters: radiologic shoulder height (RSH); T1 tilt angle; clavicle angle (CA); proximal thoracic curve (PTC), main thoracic curve (MTC), and lumbar curve (LC) Cobb measurements; and apical vertebral translation (AVT) of the PTC, MTC, and LC. Results Spontaneous PSI correction was observed in 99 (68.75%) patients. The spontaneous correction and nonspontaneous correction groups differed significantly in terms of Lenke-type preoperative LC (23° vs 26°; P = 0.091), postoperative LC (11° vs 8°; P = 0.013), LC at follow-up (13.5° vs 9°; P = 0.028), postoperative AVT of LC (− 0.8° vs − 0.4°; P = 0.033), AVT of LC at follow-up (− 0.7° vs − 0.1°; P = 0.091), PTC at follow-up (16° vs 20°; P = 0.019), and AVT of PTC at follow-up (0° vs -0.3°; P = 0.029). Multivariate analysis identified postoperative T1 tilt and postoperative LC as significantly associated with PSI correction. Conclusions The incidence of spontaneous PSI correction is high. Postoperative T1 tilt and postoperative LC are significantly associated with spontaneous PSI correction.

A novel classification of congenital cervicothoracic scoliosis: identification of coronal subtypes and their prognostic significance.

To propose a novel classification system for stratifying coronal curve patterns in congenital cervicothoracic scoliosis with hemivertebrae (CTS-HV). Type A: regional cervicothoracic deformity only disturbing the balance of head-neck-shoulder complex; Type B: cervicothoracic deformity with significant trunk tilt to the convex side; Type C: cervicothoracic deformity with a significant compensatory thoracic curve. The reliability and reproducibility were assessed via the Kappa test. The differences among different subtypes in deformity parameters and bony structures were compared to identify the causative factors predisposing to different subtypes. 98 patients were classified into Type A (47 cases), Type B (31 cases), and Type C (20 cases). The Kappa test showed excellent reliability (Kappa value = 0.847) and reproducibility (Kappa value = 0.881). The proportions of Klippel-Feil syndrome in Types B (71.0%) and C (85.0%) were significantly higher than in Type A (46.8%; all P < 0.05). Type A (66.0%) and Type B (71.0%) predominantly had their hemivertebra (HV) at T3 or T4, while Type C (75%) mostly had HV at T1 or T2. Type B exhibited the most severe trunk tilt, head shift, neck tilt, head tilt, and coronal balance distance (all P < 0.05). Type C had the lowest T1 tilt and first rib angle despite the greatest cervicothoracic Cobb angle (all P < 0.05). This novel reliable classification allows a better understanding of structural diversity and different coronal compensatory mechanisms for the natural progression of CTS-HV. It can contribute to determining the individualized treatment strategy and standardizing academic communication for this rare clinical entity.

Shoulder and Neck Balance in Adolescent Idiopathic Scoliosis: Which Radiographic Indices are Reliable and Practical?

Deformities of the spine and thorax in adolescent idiopathic scoliosis affect appearance. They are a cause of inferiority, affecting psychological well-being and the social life of the patients. To contribute to curve evaluation, planning in curve correction, and improving the post-operative aesthetics, many studies on the correlation between appearance and radiography in the assessment of shoulder and neck balance have been reported recently. In general, these studies did not clarify which indices are required to evaluate shoulder and neck balance. This study aimed to learn about indices to assess shoulder and neck balance in adolescent idiopathic scoliosis in correlation between clinical appearance and radiography. This observational study recruited 50 patients with adolescent idiopathic scoliosis who were 12 to 18 years of age with Cobb angle >10°. Based on Pearson correlation coefficient, radiographic parameters such as coracoid height difference (CHD), clavicle rib intersection distance (CRID), clavicle angle (CA), clavicle chest cage angle difference (CCAD), and T1 tilt angle were evaluated in correlation with clinical shoulder and neck balance by difference of inner shoulder height (SHi), difference of outer shoulder height (SHo), and neck tilt angle. SHi was moderately correlated with T1 tilt angle (r [hereafter] = 0.45), CA (0.47), and CHD (0.57), high-moderately correlated with CRID (0.64), very-highly correlated with CCAD (0.84). SHo was moderately correlated with T1 tilt angle (0.43), highly correlated with CHD (0.60), CA (0.63), and CRID (0.72), and very-highly correlated with CCAD (0.89). T1 tilt angle was high-moderately correlated with neck tilt angle (0.76). The correlation coefficients between clinical and radiographic shoulder and neck balance according to sex, BMI, type of main curve, severity of main curve did not change significantly. There was a very high correlation between SHo (shoulder tilt) and CCAD (0.89); the correlation between SHo and CRID was high-moderate (0.72), but CRID is easier than CCAD to evaluate on radiographs. On the other hand, T1 tilt angle, which is the easiest radiographic parameter to evaluate, had a high-moderate correlation with neck tilt angle (0.76) but a moderate correlation with SHo (0.43).

Shoulder balance in Lenke type 2 adolescent idiopathic scoliosis: correlations among radiological indices, cosmetic indices, and patient-reported outcomes.

The aim of this study was to investigate the correlation between radiological indices of shoulder balance (SB) and cosmetic indices of shoulder deformity in patients with Lenke type 2 adolescent idiopathic scoliosis (AIS) and to determine the extent to which patient-reported outcomes (PROs) correlate with these measurements. Current management decisions and outcomes for SB in AIS are primarily based on radiological measurements. It is crucial to understand how these radiological parameters and cosmetic indices relate to patient satisfaction. The authors analyzed the preoperative radiological and photographic indices of SB, along with PROs, in patients with Lenke type 2 AIS. Lateral SB parameters included the radiological shoulder height (RSH) and clavicle angle, while medial SB parameters included the first rib angle and T1 tilt angle. Photographic indices included the shoulder height angle (SHA), axilla height angle (AHA), and the left/right trapezius angle (LRTA) ratio. The authors assessed the self-image, mental health, and total score domains of the Korean version of the 22-item Scoliosis Research Society questionnaire. In their analysis of Lenke type 2 patients, the authors found that correlation coefficients between radiological measurements and photographic indices ranged from -0.25 to 0.47, among which only lateral SB including clavicle angle and RSH showed a significant correlation with anterior and posterior photographic indices. No statistically significant correlations were found between radiological measurements and PROs. Anterior photographic indices including SHA and AHA significantly correlated with all three PROs (p < 0.05). Radiological shoulder parameters did not accurately reflect the perceived SB. Anterior photographic indices were reliable for evaluating clinical SB in patients with Lenke type 2 AIS and correlated with PROs. Spine surgeons may benefit from paying more attention to anterior photographic indices when making surgical decisions regarding clinical SB.

Correlation analysis and clinical significance of changes in upper thoracic vertebra tilt and clavicle angle pre- and post-operation.

The imbalance of the lateral shoulder is reflected by the clavicle angle (CA) in radiology. It remains unclear how to achieve postoperative lateral shoulder balance (LSB) after spinal deformity correction surgery. A retrospective analysis was conducted on AIS patients who underwent surgery by the same spine surgeon at our hospital from 2016 to 2020. A total of 110 patients with spinal deformity were included in the study to verify the correlation between the T1-T5 tilt angle and CA before and after surgery, as well as the relation-ship between the change in T1-T5 tilt angle before and after surgery and the change in CA before and after surgery. By comparing the correlation coefficients, it was found that there may not be a direct relationship between the pre- and postoperative tilt angles of T1-5 and CA, but their changes were closely related to the changes in CA. The change in T1 tilt angle after orthopaedic surgery was significantly correlated with the change in CA, with a correlation coefficient of 0.976, indicating a close relationship between T1 and the clavicle. As the vertebrae moved down, the correlation gradually decreased. In summary, this study suggests that there is a close relationship between T1-T5 and the clavicle and that the change in T1 tilt angle after spinal scoliosis correction surgery is significantly correlated with CA, which decreases as the vertebra moves down.

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.

Appraisal of the New Posture Analyzing and Virtual Reconstruction Device (PAViR) for Assessing Sagittal Posture Parameters: A Prospective Observational Study.

The purpose of this study was to report the clinical validation of the posture analyzing and virtual reconstruction device (PAViR) system, focusing on the accuracy of sagittal spinal parameters, compared with the EOS imaging system. Seventy patients diagnosed with segmental and somatic dysfunction were recruited between February 2020 and November 2020. Each patient was examined using the EOS imaging system and PAViR; the sagittal parameters of human body posture [forward head posture (FHP), T1 tilt angle (T1t), knee flexion angle (KF), lumbar lordosis angle (LL), and pelvic tilt angle (PT)] were analyzed to verify the correlation between the results of the two devices. The median differences in the results of the two devices showed significant differences in FHP (T4-frontal head and T4-auditory canal), T1t, and PT. In the correlation analysis, the values of FHP (C7-auditory canal, T4-frontal head, and T4-auditory canal), T1t, and PT showed a moderate correlation between the two devices (r = 0.741, 0.795, 0.761, 0.621, and 0.692, respectively) (p < 0.001). The KF and LL was fairly correlated (r = 0.514 and 0.536, respectively) (p = 0.004, both). This study presents the potential of a novel skeletal imaging system without radiation exposure, based on a 3D red-green-blue-depth camera (PAViR), as a next-generation diagnostic tool by estimating more accurate parameters through continuous multi-data-based upgrades with artificial intelligence technology.

Strategy and Efficacy of Surgery for Congenital Cervicothoracic Scoliosis with or without Hemivertebra Osteotomy.

ObjectiveCervicothoracic scoliosis will cause severe deformities in the early stage, and its structure is complex and the surgical methods are varied. The purpose of this research is to explore the indication and analyze the corrective effect of the two different posterior approach surgical strategies, including correction with fusion and hemivertebra osteotomy, for congenital cervicothoracic scoliosis deformities in children and adolescents.MethodsThis was a retrospective study of 21 patients with cervicothoracic scoliosis who received surgical treatment from January 2010 to June 2020, including nine cases of posterior hemivertebra osteotomy and fusion surgery and 12 cases of posterior correction and fusion alone. The Cobb angle, T1 tilt angle, clavicular angle, neck tilt angle, radiographic shoulder height, sagittal vertical axis, coronal balance distance, and local kyphosis angle were measured preoperatively, postoperatively, and at the last follow‐up. Posterior approach hemivertebra resection or correction with fusion surgery was adopted based on the different individual characteristics of deformity such as main curve Cobb angle, growth potential, and flexibility. Patients were divided into two groups (osteotomy group and nonosteotomy group) according to whether a hemivertebra osteotomy was performed, and the corrective results in the two groups were compared. Paired‐sample t tests or independent‐sample t tests were used.ResultsThe median follow‐up after surgery of the 21 patients was 36 months (range, 18–72 months). The Cobb angle was corrected from 45.81° ± 14.23° preoperatively to 10.48° ± 5.56° postoperatively (correction rate, 77.78% ± 8.93%). The T1 tilt angle decreased from 15.26° ± 7.08° preoperatively to 3.33° ± 2.14° postoperatively (correction rate,73.42% ± 21.86%). The radiographic shoulder height was corrected from 1.13 ± 0.74 cm preoperatively to 0.52 ± 0.42 cm postoperatively (correction rate, 39.51% ± 35.65%). The clavicular angle improved from 2.52° ± 1.55° preoperatively to 1.16° ± 0.96° postoperatively (correction rate, 47.18% ± 35.84%). No significant differences were found at the last follow‐up (p > 0.05). The Cobb angle of the main curve, T1 tilt angle, clavicular angle, cervical tilt angle, and shoulder height difference were similar in the two groups (p > 0.05).ConclusionsPosterior approach hemivertebra resection or correction with fusion surgery can be used in the treatment of congenital cervicothoracic scoliosis with satisfactory results, and the surgeon can make an individualized surgical plan according to individual characteristics of deformity.

P50. T1 tilt and clavicle angle are the best predictors of postoperative shoulder and neck balance in AIS patients

<h3>BACKGROUND CONTEXT</h3> Shoulder imbalance after PSF is a major concern. Most studies have analyzed multiple radiographic parameters associated with postop uneven shoulders. However, there is paucity in the literature analyzing predictors for balanced shoulders. <h3>PURPOSE</h3> Shoulder imbalance after PSF is a major concern. Most studies have analyzed multiple radiographic parameters associated with postop uneven shoulders. However, there is paucity in the literature analyzing predictors for balanced shoulders. <h3>STUDY DESIGN/SETTING</h3> Retrospective review. <h3>PATIENT SAMPLE</h3> AIS patients who underwent PSF from 2012 to 2020 were included in this study. <h3>OUTCOME MEASURES</h3> Radiographic shoulder height, median shoulder height, T1 tilt, clavicle angle, first rib angle and cobb angle. <h3>METHODS</h3> Radiographic shoulder height (RSH) was used as our proxy for shoulder height. RSH. <h3>RESULTS</h3> Part I: 211 control patients were evaluated. 191 had normal RSH and 20 were abnormal. T1 tilt (2.0 vs 4.1) and CA (1.1 vs 4.95) were significantly different between the two groups (p < .05). Part II: In 186 patients, preoperative and postoperative CA correlated very strongly with RSH (r = 0.856/0.921). T1 tilt correlated moderately with RSH (r = 0.399), but was better when concordant (r = 0.51). RSH did not change significantly from immediate postop to final follow up (p=0.423). Restoring CA below 3 degrees yielded normal RSH postop (p < 0.0001). Restoring Concordant T1 tilt below 3 degrees yielded normal RSH in nearly all cases (p < 0.006). Part III: In 59 patients across 4 surgeons, restoring CA below 3 degrees yielded normal RSH at postop in all cases. Restoring concordant T1 tilt below 3 degrees yielded normal RSH at postop in nearly all cases. <h3>CONCLUSIONS</h3> Restoring shoulder balance in AIS patients is a challenging aspect of surgery. We found that restoring the CA < 3° yields normal RSH postoperatively. In addition, when T1 is concordant, restoring it to < 3 degrees can yield normal RSH. Proximal thoracic fusion did not correlate with post op RSH. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Shoulder balance in patients with Lenke type 1 and 2 idiopathic scoliosis appears satisfactory at 2years following anterior vertebral body tethering of the spine.

Shoulder balance is an important factor for patient satisfaction following surgery for idiopathic scoliosis (IS). There is no literature reporting the effect of anterior vertebral body tethering (AVBT) on shoulder balance. The purpose of this study was to report the prevalence of postoperative shoulder imbalance in patients undergoing AVBT for IS. In this retrospective case series, patients enrolled in a multicenter scoliosis registry who underwent AVBT from 2013 to 2017 in two Canadian centers were identified. The primary outcome was shoulder imbalance, defined as an absolute radiographic shoulder height of > 2cm, at 2 years postoperatively (follow-up range: 22-30months). Clavicular angle and T1 tilt angle were also investigated. Of the 50 patients identified (92% female; preoperative age: 11.9 ± 1.4years), there were 43 (86%) patients with Lenke 1 and 7 (14%) patients with Lenke 2 curves. The mean Cobb angles of the proximal thoracic and main thoracic curves were 22.8° ± 8.8° and 49.4° ± 8.5° preoperatively and 13.1° ± 7.5° and 24.9° ± 9.5° at a mean follow-up time of 2.1years. Absolute clavicular angle and T1 tilt angle were 2.8° ± 2.2° and 4.8° ± 3.5° preoperatively and 2.2° ± 1.7° and 4.7° ± 4.2° at 2-year follow-up. Preoperatively, absolute shoulder height averaged 15.6 ± 10.4mm, and 15 (30%) patients had shoulder imbalance. At 2-year follow-up, absolute shoulder height averaged 11.2 ± 8.3mm, and 8 (16%) patients had shoulder imbalance. Of the patients who had acceptable shoulder balance preoperatively, 4 (11.4%) became imbalanced at 2 years postoperatively. Postoperative shoulder imbalance in this early group of patients with IS undergoing AVBT was seen in 16% of patients, a reduction from 30% preoperatively. These results likely reflect the potential of the proximal thoracic curve to correct spontaneously following AVBT. Level III.

Evaluation of changes in shoulder balance and prediction of final shoulder imbalance during growing-rod treatment for early-onset scoliosis

BackgroundObtaining and maintaining final shoulder balance after the entire treatment course is essential for early-onset scoliosis (EOS) patients. The relatively small number of growing-rod (GR) graduates who complete final fusion has resulted in an overall paucity of research on the GR treatment of EOS and a lack of research on the shoulder balance of EOS patients during GR treatment.MethodsTwenty-four consecutive patients who underwent GR treatment until final fusion were included. Radiographic shoulder balance parameters, including the radiographic shoulder height (RSH), clavicle angle (CA), and T1 tilt angle (T1T), before and after each step of the entire treatment were measured. Shoulder balance changes from GR implantation to the last follow-up after final fusion were depicted and analysed. Demographic data, surgical-related factors, and radiographic parameters were analysed to identify risk factors for final shoulder imbalance. The shoulder balance of patients at different time points was further analysed to explore the potential effect of the series of GR treatment steps on shoulder balance.ResultsThe RSH showed substantial improvement after GR implantation (P = 0.036), during the follow-up period after final fusion (P = 0.021) and throughout the entire treatment (P = 0.011). The trend of change in the CA was similar to that of the RSH, and the T1T improved immediately after GR implantation (P = 0.037). Further analysis indicated that patients with shoulder imbalance before final fusion showed significantly improved shoulder balance after fusion (P = 0.045), and their RSH values at early postfusion and the final follow-up did not show statistically significant differences from those in the prefusion shoulder balance group (P > 0.05). Early postfusion shoulder imbalance (odds ratio (OR): 19.500; 95% confidence interval (CI) = 1.777–213.949; P = 0.015) was identified as an independent risk factor for final shoulder imbalance.ConclusionsShoulder balance could be improved by GR implantation but often changes during the multistep lengthening process, and the final result is relatively unpredictable. Final fusion could further adjust the prefusion shoulder imbalance. Focusing on the prefusion shoulder balance of GR graduates and providing patients with early shoulder balance after fusion might be necessary.

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

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

Changes in Cervical Spinal Alignment After Thoracolumbar Corrective Surgery in Adult Patients With Adolescent Idiopathic Scoliosis.

Case-control study. To examine factors influencing cervical alignment after corrective surgery for adult patients with adolescent idiopathic scoliosis (AdIS) SUMMARY OF BACKGROUND DATA.: Corrective surgery for spinal deformity influences postoperative cervical spinal alignment, but changes in the cervical alignment in adults with AdIS are scarcely reported. We retrospectively examined 85 patients with AdIS who underwent posterior corrective surgery for thoracic or lumbar major curve and were followed up for 2 years. Clinical characteristics, radiographic parameters, and health-related quality of life (HRQOL) were evaluated. Cervical deformity (CD) was defined as one of the following cases: (1) T1 tilt minus C2-C7 angle more than 20°, (2) C2-C7 SVA more than 40 mm, (3) and C2-C7 angle less than -10°. Patients were divided into those with and without CD based on the defined criteria; statistically relevant factors were analyzed. There were 19 patients in the postoperative CD group. The average age at the time of surgery was lower in the CD group (26.5 vs. 31.4). In the CD group, the average preoperative T1 tilt was smaller (1.1° vs. 12.5°), and the C2-C7 angle was kyphotic (-16.1° vs. 3.0°). The average kyphotic angle at thoracic spine (T5-T12) was lower in the CD group preoperatively (12.5° vs. 19.5°) and postoperatively (15.2° vs. 20.8°). HRQOL outcomes were comparable between the groups. Of the patients with preoperative CD, 51.5% (n = 17) maintained their deformity at the final follow-up, and baseline C2-C7 angle was lower than those who converted to non-CD following surgery (n = 16) (-17.0° vs. -10.3°). More than half of the patients with baseline CD maintained their cervical malalignment postoperatively. Patients with postoperative CD presented cervical kyphotic and thoracic hypokyphotic alignments before surgery. Because CD has the potential to lead to cervical degeneration, careful follow-up observation is necessary for these young patients. 3.

A Positive (+ve) Postoperative Upper Instrumented Vertebra Tilt Angle (≥0°) Significantly Increases the Risk of Medial Shoulder and Neck Imbalance in Lenke 1 and 2 Adolescent Idiopathic Scoliosis Patients.

Retrospective study. To investigate the relationship between a +ve postoperative Upper Instrumented Vertebra (UIV) (≥0°) tilt angle and the risk of medial shoulder/neck and lateral shoulder imbalance among Lenke 1 and 2 Adolescent Idiopathic Scoliosis (AIS) patients following Posterior Spinal Fusion. Current UIV selection strategy has poor correlation with postoperative shoulder balance. The relationship between a +ve postoperative UIV tilt angle and the risk of postoperative shoulder and neck imbalance was unknown. One hundred thirty-six Lenke 1 and 2 AIS patients with minimum 2 years follow-up were recruited. For medial shoulder and neck balance, patients were categorized into positive (+ve) imbalance (≥+4°), balanced, or negative (-ve) imbalance (≤-4°) groups based on T1 tilt angle/Cervical Axis measurement. For lateral shoulder balance, patients were classified into +ve imbalance (≥+3°) balanced, and -ve imbalance (≤-3°) groups based on Clavicle Angle (Cla-A) measurement. Linear regression analysis identified the predictive factors for shoulder/neck imbalance. Logistic regression analysis calculated the odds ratio of shoulder/neck imbalance for patients with +ve postoperative UIV tilt angle. Postoperative UIV tilt angle and preoperative T1 tilt angle were predictive of +ve medial shoulder imbalance. Postoperative UIV tilt angle and postoperative PT correction were predictive of +ve neck imbalance. Approximately 51.6% of patients with +ve medial shoulder imbalance had +ve postoperative UIV tilt angle. Patients with +ve postoperative UIV tilt angle had 14.9 times increased odds of developing +ve medial shoulder imbalance and 3.3 times increased odds of developing +ve neck imbalance. Postoperative UIV tilt angle did not predict lateral shoulder imbalance. Patients with +ve postoperative UIV tilt angle had 14.9 times increased odds of developing +ve medial shoulder imbalance (T1 tilt angle ≥+4°) and 3.3 times increased odds of developing +ve neck imbalance (cervical axis ≥+4°). 4.

Pedicle screw instrumentation with or without pelvic fixation in neuromuscular scoliosis: Outcome and complications in a series of 37 patients with a minimum 2-year follow-up

ObjectiveNeuromuscular scoliosis (NMS) is often associated with rapid progressive spinal deformities. Indications, when to extend the instrumentation to the pelvis for pelvic obliquity are not generally accepted at this time. This study reports on the indications, surgical technique and results using pedicle screw instrumentation exclusively with or without pelvic fixation for spine fusion in patients with NMS. Patients and methodsThirty-seven NMS patients were treated with pedicle screw instrumentation (PSI) between 2007 and 2013 with a minimum follow-up of 24 months. The mean age at the time of operation was 14.91 ± 2.03 years (range, 11.17–18.58). Posterior spine fusion (PSF) was conducted in 33 patients; 4 patients underwent a combined anterior spinal release followed by PSF during one-stage surgery. Pelvic fixation was achieved by ilium screws combined with S-1 screws in 4 cases and by sacral-alar-iliac (SAI) technique by Sponseller in 9 cases, respectively. ResultsThe mean primary Cobb angle was 65.5° (range, 14–103°) and improved significantly to 19.8° (range, 1–50°, p < 0.001) after surgery and 20.5° (range, 3–57, p = 0.47) at 2 years FU, respectively. Besides, an improvement of pelvic obliquity and T1 tilt angle could be detected. Major complications occurred in 19% and minor complications in 32%. ConclusionPedicle screw fixation only for spine fusion in patients with NMS can be applied safely with reasonable complication rates. An excellent correction in all planes, a significant improvement of the pelvic obliquity and almost no loss of correction at 2 years FU were observed.

Excessive correction impacts postoperative shoulder imbalance in lenke type 5C adolescent idiopathic scoliosis

BackgroundPostoperative shoulder imbalance (PSI) has a negative impact on the surgical outcomes of patients with adolescent idiopathic scoliosis. This study aimed to evaluate the risk factors of PSI in patients with Lenke type 5C curves. MethodsThis study included 100 patients who underwent posterior correction surgery using pedicle screw constructs for Lenke type 5C curves. The mean age of the patients at surgery was 15.5 ± 2.3 years, and the mean follow-up period was 36.6 ± 15.0 months. The subjects were classified into the following two groups: PSI and non-PSI. Radiographic parameters, including the preoperative and 2-year postoperative coronal and sagittal profiles, were compared between the two groups. ResultPSI was found in eight patients (8.0%). The preoperative Cobb angles were 47.3° ± 8.7° and 48.0° ± 3.9° in the non-PSI and PSI groups, respectively. The correction rate in the PSI group was significantly higher than that in the non-PSI group (81.0% ± 17.7% vs. 67.7% ± 14.7%; p = 0.018). The preoperative T1 tilt angle in the PSI group was significantly larger than that in the non-PSI group (6.1° ± 3.3° vs. 3.1° ± 2.8°; p = 0.005). Receiver operating characteristic (ROC) analysis showed that the area under the ROC curve was 0.769 (p = 0.012, 95% confidence interval [CI], 0.556–0.982) and 0.763 (p = 0.014, 95% CI, 0.598–0.928) for the correction rate and preoperative T1 tilt, respectively. The cut-off value was 73% and 4° for the correction rate and preoperative T1, respectively. ConclusionPSI was found in 8.0% of Lenke type 5C curves. Excessive correction of the lumbar curve of >73% and preoperative T1 tilt of >4° can be risk factors for PSI in patients with Lenke type 5C curve.

195. Residual curve and truncal shift impact patient satisfaction after surgery for adolescent idiopathic scoliosis

BACKGROUND CONTEXT Prior adolescent idiopathic scoliosis (AIS) literature has demonstrated that patient satisfaction correlated weakly with individual SRS-22r domains and did not correlate with specific radiographic parameters. PURPOSE The purpose of this study is to demonstrate the effect of residual deformity on patient satisfaction. We hypothesize that in patients with AIS, residual deformity maybe associated with worse satisfaction. STUDY DESIGN/SETTING Retrospective analysis of a prospective AIS registry. PATIENT SAMPLE A total of 1,229 Lenke 1 and 2 AIS patients with available radiographic data and SRS scores at the 2-year follow-up were included. OUTCOME MEASURES Patient satisfaction using the SRS-22r satisfaction domain, categorized into 2 groups: Complete satisfaction (5/5) and incomplete satisfaction/dissatisfaction ( METHODS A total of 1,229 Lenke 1 and 2 AIS patients with available radiographic data and SRS scores at the 2-year follow-up were included. A score of 5 on the SRS-22r satisfaction domain at 2 years was considered “complete satisfaction,” and anything below a score of 5 was considered “incomplete satisfaction/dissatisfaction.” Radiographic parameters that were 2 standard deviations below the mean were deemed to have a “residual deformity.” Univariate and binary logistic analyses were performed to assess the association of residual deformity with patient satisfaction. RESULTS At the 2-year follow-up, 689 (60%) patients reported complete satisfaction, while 455 (40%) reported incomplete satisfaction/dissatisfaction. Radiographic factors associated with incomplete satisfaction/dissatisfaction were: residual trunk shift (OR 3.32, p=0.001) and residual major curve (OR 1.7, p=0.036). Patients with residual trunk shift and major curve also had worse SRS-22r self-image domain scores at the 2-year follow-up. Residual differences in shoulder height (p=0.534), T1 tilt angle (p=0.062), Apex to CSVL distance (p=0.969), and percent correction of the major curve (p=0.102) did not reach statistical significance for predicting incomplete satisfaction/dissatisfaction. CONCLUSIONS Residual curve (>34) and truncal shift (>2.2cm) impact patient satisfaction after surgery for AIS. These factors ought to be taken into account during surgical planning. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

287. T1 tilt and clavicle angle are the best predictors of postoperative shoulder balance in AIS patients: a review of 347 cases

BACKGROUND CONTEXT Shoulder imbalance after PSF is a major concern. Most studies have analyzed multiple radiographic parameters associated with postop uneven shoulders. However, there is paucity in the literature analyzing predictors for balanced shoulders. PURPOSE This study evaluated XRs of AIS patients who underwent PSF, and control patients (no spinal curvature) to identify radiographic predictors of shoulder balance. STUDY DESIGN/SETTING Ambispective review. PATIENT SAMPLE A total of 347 AIS patients that underwent PSF. OUTCOME MEASURES T1 tilt, clavicle angle, radiographic shoulder height (RSH). METHODS Radiographic shoulder height (RSH) was used as our proxy for shoulder height. RSH RESULTS Part I: 211 control patients were evaluated. Of these, 191 had normal RSH and 20 were abnormal. T1 tilt (2.0 vs 4.1) and CA (1.1 vs 4.95) were significantly different between the two groups (p CONCLUSIONS Restoring shoulder balance in AIS patients is a challenging aspect of surgery. We found that restoring the CA FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Shoulder Balance and Scoliosis: The Unresolved Issue

Background Data: The main indication of surgery in patients with AIS is better function and cosmesis. Shoulder balance should be considered amongst cosmetic parameters that are strongly associated with patient satisfaction after surgery in patients with AIS. Proper correction of the main and proximal thoracic curves in conjunction with horizontalization of upper instrumented vertebra (UIV) is supposed to promote shoulder balance. In other words, better correction of radiological parameters should promote clinical shoulder balance; however, this is not always observed.Purpose: Determining which of the following radiological measures correlate significantly with postoperative clinical shoulder balance: T1 tilt, UIV tilt, clavicle rib intersection angle, and degree of proximal thoracic curve correction.Study Design: Retrospective clinical case cohort study.Patients and Methods: The study included 20 patients of AIS operated for correction by pedicle screw instrumentation. There were 13 females and 7 males. The mean age at the time of surgery was 14±2.4 years with a range from 11 to 18 years. Mean preoperative Cobb angle of the major curve was 76.1±21.7° corrected to a mean postoperative Cobb 28.2±14.2°. Correction percentage of the major curve was 63.1±14.2%. The data obtained from high resolution back view photographs (to assess clinical shoulder balance) and whole spine X-ray films taken within the first year of follow-up period (to assess radiological measures related to shoulder balance) were retrospectively evaluated. Outcome measures: clinical shoulder balance was correlated with 4 radiological parameters, namely, proximal thoracic curve correction percentage, T1 tilt, UIV tilt, and clavicle-rib intersection angle. Measurements were done by Surgimap software version 2.2.12 (Nemaris, Inc.,US, https://www.surgimap.com).Results: A weak positive correlation was found between postoperative shoulder balance and UIV tilt (r)=0.242, P=0.305, and a very weak negative correlation was found between postoperative shoulder balance and proximal thoracic curve correction percentage (r)=-0.027, P=0.910. A moderate positive correlation but statistically nonsignificant was found between postoperative shoulder balance and T1 tilt (r)=0.440, P=0.052, and a statistically significant positive correlation was found between shoulder balance and clavicle rib intersection angle (r)=0.567, P=0.009.

Upper Instrumented Vertebrae (UIV) Tilt Angle Is an Important Postoperative Radiological Parameter That Correlates With Postoperative Neck and Medial Shoulder Imbalance.

Retrospective study. To investigate the association between postoperative upper instrumented vertebrae (UIV) tilt angle with postoperative medial shoulder and neck imbalance. Studies had found that current recommendations for UIV selection were not predictive of good postoperative shoulder balance. A total of 98 patients with adolescent idiopathic scoliosis with Lenke 1/2 curves who underwent posterior spinal fusion between 2013 and 2014 with minimum follow-up of 2 years were recruited. Radiological parameters: UIV tilt angle, T1 tilt, cervical axis, and clavicle angle were measured preoperatively, postoperatively, and at final follow-up. Mean age was 16.2 ± 6.2 years. Mean follow-up was 37.9 ± 6.5 months. There were 73.5% Lenke 1 and 26.5% Lenke 2 curves. Significant factors affecting postoperative T1 Tilt were postoperative UIV tilt angle, preoperative T1 tilt, and preoperative UIV tilt angle. Postoperative UIV tilt angle and preoperative cervical axis were significant factors affecting cervical axis at final follow-up. UIV level was not significant independent factor that affected postoperative T1 tilt and cervical axis. There was strong correlation between postoperative UIV tilt angle and T1 tilt for the whole cohort (P < 0.001), when UIV was at T2 (P < 0.001), T3 (P < 0.001), and T4 (P < 0.001). Postoperative UIV tilt angle also had significant correlation with cervical axis when UIV was at T2 (P = 0.021) and T3 (P = 0.009). Postoperative UIV tilt angle was an independent factor, which had significant correlation with postoperative T1 tilt and cervical axis measurement. There was strong correlation between postoperative UIV tilt angle and T1 tilt for the whole cohort, when UIV was at T3 and T4. There was very strong correlation between postoperative UIV tilt angle and T1 tilt when UIV was at T2. There was also moderate and significant correlation between postoperative UIV tilt angle and cervical axis for the whole cohort. 2.