The association of lumbar curve magnitude and spinal range of motion in adolescent idiopathic scoliosis: a cross-sectional study.

BACKGROUND: Spinal deformities affect the overall alignment of the spine and thus the vectors of loading on the lumbar region and intervertebral discs. Due to wedging of the disc or vertebrae of unbalanced spinal segments, alignment change may affect the range of motion (ROM) of individual spinal segments or the global spine. This is particularly important in adolescent idiopathic scoliosis (AIS) patients who may suffer from early degeneration, back stiffness and pain. Hence, this study aimed to determine the correlation between spine range of motion (ROM) and adolescent idiopathic scoliosis (AIS) curve magnitude. METHODS: Consecutive recruitment of all AIS patients with Lenke 5 (thoracolumbar/lumbar) curves within one month was performed with ROM assessments in the coronal, sagittal and axial planes using the change in C7-S1 distance on standing upright, active flexion and extension positions, change in finger-floor distance on forward bending position and lateral bending, lateral bending angles, modified Schober's test, and trunk rotation in seating position. Patients were further stratified into two groups based on their lumbar spine curve magnitude: Group A with curves of 10 to 39 degrees and Group B with 40 degrees or greater. Univariate and multivariate analyses were conducted, with lumbar curve magnitude severity being the dependent variable. RESULTS: In total, 58 patients (n = 12 males, n = 46 females; mean age: 15.7 years) were recruited. The mean curve magnitudes were 25 ± 6.5 degrees in Group A and 48 ± 10.6 degrees in Group B. Mean axial rotation (Group A: 90 ± 21.7 degree; Group B: 76 ± 19.6 degrees; p = 0.038) and lateral bending ROM (Group A: 67 ± 13.4 degrees; Group B: 58 ± 14.3 degrees; p = 0.045) decreased in more severe curves. These two parameters continued to remain significant irrespective of the curve severity cut-off values. CONCLUSIONS: This is the first study to determine associations between spinal ROM parameters with the lumbar curve magnitude in AIS patients. We found that the coronal curve severity is associated with reduced axial and coronal ROM. This is a platform for future studies assessing lumbar spine biomechanics in AIS and to determine the effects of altered spine motion in this context and its implication in patient management and outcomes.

Effects of total hip arthroplasty on spinal sagittal alignment and static balance: a prospective study on 28 patients.

PURPOSE: The aim of this study was to investigate postoperative changes in spinal sagittal alignment and postural balance in patients with hip-spine syndrome (HSS) and to verify whether any significant correlation exists between these changes and improvement of low back pain (LBP) symptoms following total hip replacement (THR) surgery. METHODS: Twenty-eight consecutive patients with HSS undergoing unilateral THR were prospectively enrolled. Whole spine X-rays were obtained before surgery and 6 months after surgery. The following parameters were measured: cervical lordosis, thoracic kyphosis, lumbar lordosis, pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), and sagittal vertical axis (C7 SVA). Patients underwent pre- and postoperative postural balance assessment (950-460 BioSwayTM system; clinical test of sensory integration-CTSIB, limit of stability test-LOS) and patient reported outcome measures assessment (Short Form-36, SF-36, Oswestry Disability Index, ODI, Visual Analog Scale, VAS and Western Ontario and McMaster Universities Arthritis Index, WOMAC). RESULTS: Mean age of the patients was 61.7 ± 6.4. Median (interquartile range, IQR) pre-operative PI and PT were 50.0 (35.0, 60.0) and 11.0 (7.0, 23.0), respectively; lumbar lordosis was 49.0 (41.0, 68.0) and SVA 5.0 (-11.0, 41.0). No significant changes in sagittal alignment were observed postoperatively. Median LBP VAS decreased from 6.0 (5.0, 7.0) to 3.0 (2.0, 4.0) and ODI from 54.0 (39.0, 64.0) to 34.0 (26.0, 48.0) (p < 0.001). Median CTSIB improved from 1.22 (1.07, 1.45) to 1.01 (0.80, 1.19) and LOS from 46.0 (42.0, 58.0) to 37.0 (32.0, 39.0) postoperatively. No significant correlation was noted between postoperative changes in spinal sagittal alignment or postural balance and improvement of LBP VAS and ODI scores. CONCLUSIONS: Our study demonstrated an improvement in LBP levels (VAS and ODI) and postural balance in patients with HSS following THR surgery. No significant changes have been noted in radiographic spinal sagittal alignment postoperatively. The improvement in LBP levels does not correlate with post-operative changes in spinopelvic alignment or postural balance.