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

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

How Is Degenerative Lumbar Scoliosis Associated with Spinopelvic and Lower-Extremity Alignments in the Elderly

Methods@#Adult volunteers aged over 50 years were included in the study after participating in the screening program. Characteristic data and standing radiographic parameters were assessed. A propensity score model was established with adjustments for age and sex after a preliminary analysis, and cases were divided into DLS (Cobb angle >10°) and non-DLS (Cobb angle ≤10°) groups. @*Results@#There were significant differences in age, sex, C2 sagittal vertical axis (C2-SVA), C7-SVA, T1 pelvic angle (TPA), lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), PI minus LL (PI–LL), knee angle, ankle angle, pelvic shift, C7-center sacral vertical line, L4 tilt, femur-tibia angle, and hip-knee-ankle angle (all p <0.05) using a preliminary analysis of 261 cases (75 DLS and 186 non-DLS). A one-to-one propensity score-matched analysis was used after 70 pairs of cases were selected. There were no significant differences in the characteristic data for lower extremity parameters. There were still significantly higher values of C2-SVA, TPA, PI, PT, and PI–LL in DLS group than in non-DLS group (all p <0.05). @*Conclusions@#This study showed an important relationship between DLS and sagittal spinal deformity. However, DLS was not associated with the sagittal and coronal lower extremity alignments.

Novel Measurement Technique for the Sagittal Vertical Axis and Its Clinical Application in Adult Spinal Deformity

STUDY DESIGN: Prospective physical measurement of the sagittal vertical axis (SVA). PURPOSE: To evaluate a simple method for measuring SVA by analyzing its relationship with radiographic measurements and clinical appearance. OVERVIEW OF LITERATURE: No studies have examined physical measurements using the cranial center of gravity (CCG) in a relaxed standing position. METHODS: The physical measurement of the horizontal distance between CCG and spina iliaca posterior superior (CCG-SIPS) was measured using a straight ruler in 252 healthy volunteers and 56 patients with adult spinal deformity. Health-related quality of life (HRQOL) was evaluated using the Oswestry disability index (ODI), and clinical symptoms were assessed according to standing status and the presence of gastroesophageal reflux disease (GERD). RESULTS: CCG-SIPS increased with age in the volunteer group and strongly correlated with radiographic SVA in the patient group (r=0.984). Differences increased between CCG-SIPS in patients in the relaxed position and radiographic SVA with an increase in sagittal malalignment (r=0.692, p120 mm) was significantly larger in the patient group than in the group with low sagittal malalignment (59.9±18.8 vs. 45.1±17.0; p=0.004); these patients (CCG-SIPS>120 mm) needed crutches or walkers for standing. The patient group with GERD had significantly larger sagittal malalignment than the group without GERD (160.3 mm vs. 81.0 mm). CONCLUSIONS: The CCG-SIPS correlated with age and strongly reflected radiographic SVA and HRQOL in the patients. Moreover, it reflects a relaxed posture without a backward shift in the radiographic position even in patients with severe sagittal malalignment. The critical limit of CCG-SIPS can be relevant to clinical appearance, including standing assistance (>120 mm) and the existence of GERD (>150 mm). Thus, it will be a useful predictor of true SVA in clinical practice before radiographic evaluation.