The effect of an interspinous process implant on facet loading during extension.

Study Design: Facet loading parameters of lumbar cadaver spines were measured during extension before and after placement of an interspinous process implant.

Objective: The study was undertaken to quantify the influence of an interspinous implant on facet loading at the implanted and adjacent levels during extension.

Summary Of Background Data: Facet loading is increased during extension and decreased during flexion.