Sabarul A. Mokhtar MD, PhD
President of Malaysia Spine Society
Senior consultant Orthopaedic surgeon
Department of Orthopaedics & Traumatology
Faculty of Medicine
Universiti Kebangsaan Malaysia

 

The pelvis plays an important role in the sagittal balance of the spinal column by its orientation and compensatory mechanism. The current sagittal balance measurements of the spine are defined in relation to the physiologic sacral end plate angle using the pelvic incidence technique by encompassing the measurement of pelvic incidence, sacral slope and pelvic tilt. Theoretical optimum lordosis can be evaluated from the measurement of the pelvic incidence. Lumbosacral disorders are commonly associated with sagittal imbalance. The mainstay of deterioration in quality of life (QOL) is largely due to sagittal imbalance with kyphotic deformity and retroverted pelvis. Whether it is well compensated or not depends on the ability of the compensatory mechanism within the lumbosacral area and even the lower limbs. These phenomena can translate into a cascade of functional, neurological and mechanical events. Lumbosacral fusion surgery is one of the mainstay of treatment when non operative modalities or decompression alone are not successful. Fusion of functional spinal unit make changes to the mobility and biomechanics of the spinal column. Not restoring adequate lumbar lordosis during lumbar fusion surgery may result in mechanical low back pain, further sagittal imbalance due to decompensation and adjacent segment degeneration.