Relationship between spinal imbalance and knee osteoarthritis by using full-body EOS

Area of Science:

• Orthopedics and Biomechanics
• Spinal Health
• Lower Limb Biomechanics

Background:

• Orthostatic balance relies on spinal, pelvic, and lower extremity coordination.
• Spinal imbalance is linked to osteoarthritis, but compensatory mechanisms like pelvic tilt and knee flexion require further assessment.

Purpose of the Study:

• To investigate the relationship between sagittal spinal imbalance and lower extremity joint parameters.
• To assess compensatory mechanisms in spinal imbalance.
• To explore the association between spinal alignment and knee/low back pain.

Main Methods:

• Radiological measurements (EOS imaging) of spinal and lower extremity parameters in 213 adults over 40.
• Classification of subjects into decompensated, compensated, and normal spinal balance groups based on PI-LL values.
• Analysis of radiographic parameters and correlation with knee society score (KSS) and Oswestry disability index (ODI).

Main Results:

• Decompensated spinal imbalance groups exhibited significantly larger pelvic tilt and lower extremity parameters (hip-knee-angle, knee flexion angle) compared to the normal group.
• Compensated spinal imbalance showed larger pelvic tilt but no significant difference in lower extremity parameters compared to the normal group.
• Spinal parameters were greater in individuals with patellofemoral pain, and higher PI-LL values were noted in women.

Conclusions:

• A significant correlation exists between sagittal spinal imbalance and knee joint angles.
• The severity of sagittal spinal imbalance is associated with the progression of knee and low back pain.
• Pelvic retroversion is identified as a likely compensatory mechanism for sagittal spinal imbalance.