Rat Model for Developmental Lumbar Spinal Stenosis

Dr Cheung, Jason Pui Yin   (Principal Investigator (PI))

Professor Cheung Kenneth Man Chee   (Co-Investigator)

Professor Yeung Kelvin Wai Kwok   (Co-Investigator)

Dr Leung Victor Yu Leong   (Co-Investigator)

Dr Hu Yong   (Co-Investigator)

12

2015-06-30

2016-06-29

35400

Rat Model for Developmental Lumbar Spinal Stenosis

Developmental Spinal Stenosis, Lumbar spine, Rat model

Orthopaedics/Traumatology

201411159078

Seed Fund for PI Research – Basic Research

2014

Completed

Lumbar spinal stenosis is the narrowing of the lumbar spinal canal resulting in compression of the dural sac and nerve roots. Patients present with radicular leg pain, claudication and reduction in walking tolerance which limits their productivity in society. As one of the commonest spinal pathologies, luumbar spinal stenosis increases healthcare costs and reduces general quality of life. Despite surgical decompression for treatment of symptoms, it is not uncommon for repeated surgery to treat symptom recurrence. These individuals are especially at risk due to developmental spinal stenosis (DSS). DSS is a result of abnormal fetal and postnatal development of the lumbar vertebrae.(1-3) Due to congenital malformation, the pedicles and laminae are short which makes the neural elements more susceptible to compression and symptomatic stenosis.(4-6) There is also decreased interpedicular distances(7) and vertebral bodies may be wedged with its posterior lipping contributing to neural compression in the narrow spinal canal.(8) Despite the work regarding its phenotype on MRI and genetic origins(9-11), the prevalence, clinical presentation or natural history of DSS is still unknown. Thus, further investigation into the relationship between canal stenosis and symptoms is required to better understand this pathology. Our hypothesis is that there is an inverse relationship between DSS degree and the amount of further compression required to cause symptoms and the severity of soft tissue hypertrophy. In addition, DSS has reduced threshold to chronic compression. The initial step for testing our hypothesis is to apply an animal model. Although there are models to test degenerative spinal stenosis from a one-directional compression(12-19), these models can only recreate the anterior compression that mimics disc protrusions and posterior compression to mimic ligamentum flavum and facet hypertrophy. Currently, there are no options to test DSS which is a circumferential compression of the dura sac. Hence, the objectives of this study is to create a reproducible rat model representing lumbar DSS.