Relationship between lumbar instability and radiographic parameters：a kinetic MRI report

English Keywords:Kinetic MRI  Lumbar instability  Disc degeneration  Facet joint osteoarthritis  Ligamentｕｍ flavum hypertrophy

English Abstract:

  【Abstract】 Objective：To evaluate the relationship between lumbar instability and parameters in the functional spinal unit including disc degeneration，facet joint osteoarthritis and ligamentum flavum hypertrophy.Method：According to the Kong′s criteria，79 cases（a total of 237 functional spinal units）with lumbar instability were subjected to MRI under neutral，flexion and extension position.Segmental range of motion was measured at three levels（L3/L4，L4/L5，L5/S1）.Then three radiographic parameters including disc degeneration（gradeⅠ-Ⅴ），facet joint osteoarthritis（grade 1-4） and ligamentum flavum hypertrophy（>3mm indicating the presence of ligamentum flavum hypertrophy）　were used to evaluate the relationship between them and lumbar instability.Result：L4/5 instability（36 cases）　was more prevalent than L3/4（18 cases）　and L5/S1（25 cases）.Disc degeneration，facet joint osteoarthritis and ligamentum flavum hypertrophy all showed relationship with L3/L4，L4/L5 and L5/S1 instability（P<0.05）.Conclusion：Radiographic parameters including grade Ⅳdisc degeneration，grade 3 facet joint osteoarthritis and ligamentum flavum hypertrophy（+） participate in the development of lumbar instability，which can be used to determine lumbar instability.