Residual Lower Extremity Pain after Decompression and Posterolateral Fusion for Lumbar Spondylolisthesis is often Related to Bone Graft Harvest

137 patients had undergone 1-level posterolateral lumbar fusion for grade 1-2 spondylolisthesis. All patients had iliac crest bone graft site harvest contralateral to the side with the more severe radiculopathy preoperatively. 23 patients continued to have some LE pain after surgery. In 19 patients this pain was on the bone graft side. Postop physical examination demonstrated that in all 19 of these patients, radicular signs were absent but tenderness localized to the buttock/ posterior iliac crest area was present. Only 1 of the 23 patients had true residual radiculopathy. Fisher’s exact test showed that patients with residual LE pain were much more likely to have pain from the bone graft site rather than radiculopathy (p<0.01).