Could skin retraction incision minimize nerve injury over the iliac crest?

The aim of this study is to elucidate the nerve passage over the iliac crest shifted by skin retraction in harvesting iliac bone graft. A total of 44 iliac crests obtained of 22 nonembalmed Korean fresh cadavers were dissected (six males and 16 females; age range, 57-91 years). In A group (22) of "reposed skin," a skin incision was made from the anterior superior iliac spine (ASIS) to the highest level of iliac crest (HLIC). In B group (22) of "medial retraction," skin was tugged medially 1.5 cm and an incision was made from ASIS to HLIC. In A group, the nerve branches were injured in 19 (86.4%) and 15 (68.2%) in B group. Most injured nerves crossed over the iliac crest and at the posterior half site of ASIS to HLIC. The involved nerves were the subcostal nerve, iliohypogastric nerve, and ilioinguinal nerve. Subcostal nerve was less inflicted with injury in B group (one branch, 4.5%) than A group (four branches, 18.2%). P value is 0.151. Iliohypogastric nerve was significantly least injured in B group (three branches, 13.6%) compared with A group (10 branches, 45.5%). P value is 0.022. An injuring rate of ilioinguinal nerve was almost the same between A group (13 branches, 59.1%) and B group (14 branches, 63.61%). P value is 0.760. In the procedure of harvesting iliac bone graft, it is suggested to make an incision on the skin retracted medially and on the anterior half site of ASIS to HLIC to avert an injury of superficial sensory nerves.