The Lateral Buttress: An Anatomic Feature of the Lumbar Pars Interarticularis

Abstract

This study provides descriptive and anatomic data regarding the lateral buttress portion of lumbar pars interarticularis. The broad buttress of the upper lumbar levels offers support to the pars but can confuse anatomic guidelines for pedicle screw placement and paraspinal approaches. The narrow buttress of lower lumbar levels makes pedicle screw placement and the paraspinal approach easier, but it lessens support to the pars, making spondylolysis and iatrogenic instability more likely.