Introduction: Lumbar facet anatomy can play an important role in spinal stability and anatomical changes in the facet may represent the consequences spinal instability. However there are few studies illustrating how morphometric analysis of the facet can help to determine the most favorable surgical approach.
Methods: 10 patients having undergone minimally invasive decompression with or without instrumentation for stenosis were retrospectively analyzed. Morphometric analysis of 28 lumbar facets at the index level were analyzed in the preoperative lumbar MRI at the mid-disc space level using a longitudinal measurement of the superior and inferior facet. (figure 1)
Results: 6 (60%) males and 4 (40%) females with an average age of 55 years old underwent facet morphometric analysis of the following levels: L3-4 (30%), L4-5 (60%) and L5-S1 (60%) and multiple level involvement (30%). Those patient who underwent decompression alone had average facet longitudinal facet morphology of 11.1 mm superior facet of inferior vertebral body and 16.3 mm of inferior facet of superior vertebral body. This compared with average longitudinal facet morphology in spondylolisthesis patients of 24.7mm superior facet of inferior vertebral body and 30 mm of inferior facet of inferior vertebral body. Patients with elongation of facets underwent MIS TLIF (40%) whereas relatively normal facet ratios underwent decompression alone (60%).
Conclusions: the length of Lumbar facet may be an important morphometric factor to suggest spinal instability and could determine the need for instrumented fusion to improve spinal stability while improving clinical symptoms.
Patient Care: Improving clinical symptoms based in morfological analysis of zygapophysial joints.
Learning Objectives: By the conclusion of this session, participants shoul be able to: Identify the morphometric changes of lumbar facet larger that 14mm may be an indication of instrumented fusion.