Multimodal Bio-mechanical Analysis of Adult Spinal Deformity With Sagittal Plane Misalignment
A good understanding of the principles of balance is vital to achieve optimal outcomes when treating spinal disorders. A complex interaction of the neuromotor system and muscular recruitment is necessary for ergonomic balance and deliberate displacement of the human body. Sagittal plane misalignment in spinal deformities challenges balance mechanisms used for maintenance of an upright posture. The occurrence of postoperative complications after spinal deformity correction like under-correction of sagittal misalignment, postoperative reciprocal changes in thoracic kyphosis, proximal junctional kyphosis and failure of instrumentation are possibly due to the current state-of-the art inadequate diagnostic work-up. Investigators do not fully understand the roll of vision and exact strategy of recruitment of neuromuscular units (trunk, pelvis, lower limbs) in patients with sagittal plane misalignment during standing and walking. To understand this, a dynamic evaluation of individuals with spinal deformities is needed. Currently there is only very little research performed in the field of clinical balance tests and instrumented movement analysis in patients with spinal deformity. The challenge for future studies is to further unravel the relation between trunk and lower limb movements, grouped into functional movement patterns. Moreover, additional information on trunk and lower limb kinetics and muscle activity (using dynamic electromyography (EMG)) will highly contribute to the understanding of this functional relationship, and will provide more in-depth insights into compensatory mechanisms of the trunk versus the lower limbs and vice versa.
• Pathological group
‣ Age \>= 45 years
⁃ Diagnosis of adult congenital, degenerative, idiopathic or iatrogenic spinal deformity
⁃ Scoring at least 25 out of 30 on Mini Mental State Examination
⁃ Ability to walk at least 50 meters distance independently without a walking aid
⁃ Sagittal malalignment: PI-LL ≥ 25 degrees; sagittal vertical axis \>5cm; pelvic tilt \>25° and/or thoracic kyphosis \> 60° and/or coronal malalignment: thoracic scoliosis 30 ≥ degrees; thoracolumbar/lumbar scoliosis ≥ 30 degrees; global coronal malalignment \>3cm, posterior spinal fusion \> 4 levels + iliac fixation.
⁃ Ability and willingness of patient to attend follow-up visits and complete patient questionnaires
⁃ Completed patient informed consent
• Control group
‣ Asymptomatic adults not suffering from a spinal deformity leading to a pathological sagittal alignment presenting as volunteer in the University Hospitals Leuven, Belgium
⁃ Age \>=45 years old
⁃ Scoring at least 27 out of 30 on Mini Mental State Examination
⁃ Ability to walk at least 1000 meters distance independently without a walking aid
⁃ Ability and willingness of patient to attend follow-up visits and complete patient questionnaires
⁃ Completed patient informed consent