Effect of age and lumbar spinal stenosis on static and dynamic sagittal spinal balance: Single center observational pilot study

Background
Spinal balance (SB) can be described by global or local parameters and is usually determined using X-ray images. 3D motion analysis allows to record similar parameters dynamically. Research has linked symptomatic lumbar stenosis (sLSS) with alterations of SB. The aim of this pilot study was to investigate whether SB differs between three groups during standing and walking.
Methods
In 10 patients with sLSS (5M/5F; age, 70±10 years; body mass index (BMI), 29.3±4.8 kg/m2), 10 older controls (5M/5F; 65±5 years; 24.7±5.8 kg/m2), and 10 young controls (5M/5F; 26±2 years; 22.3±2.3 kg/m2), SB was determined using 18 reflective markers. Additionally, SB was calculated from radiographs for patients with sLSS and older controls. Calculation of marker-based SB was based on a cubic polynomial fitted to the marker positions. Correlation between marker- and radiograph-based SB was assessed using Pearson correlation. The influence of group and activity on SB was assessed by one-way ANOVA, repeated-measures ANOVAs, and paired-samples post hoc t tests with Bonferroni correction.
Results
Marker-based and radiographic thoracic kyphosis and lumbar lordosis correlated significantly (r=0.715, p<0.001; r=0.526, p=0.017). There was a group effect for thoracic kyphosis (p=0.007, older controls > young controls). Spine inclination differed between groups (patients > young controls; older controls > young controls) and movements (walking > standing, all p<0.001).
Conclusions
SB seems to be mainly affected by age, independent of sLSS. Spine inclination increases in motion across all groups. Further research is needed to investigate the influence of fatigue or worsening symptoms in patients with sLSS.