Degenerative spondylolisthesis
It typically involves the L4-L5 level.
Cephalad portion of the facet joints more sagittally oriented.
Caudad portion of the facet jointsmore coronally oriented.
More common in patients with transitional L5 vertebra and vertically oriented facet joints.
Commonly causes L5 radiculopathy due to compression of the L5 nerve root between the hypertrophic and subluxed inferior facet of L4 and the superior body of L5.
Treatment
Decompression of the nerve roots and stabilization by instrumented posterolateral fusion.
Dynamic stabilization.
Facet screw fixation.