Unmet Need Pain Perspectives in Iliac Crest Bone Marrow Aspiration Most common bone marrow aspiration procedure is performed using the iliac crest. This procedure is painful in the short and the long term. Iliac Crest Harvesting: Hospital Procedure Challenges The iliac crest harvesting is complicated procedure – mainly in a hospital setup. Tibial Bone vs. Marrow Harvesting: Stem Cell Yield Comparison It is assumed that tibial bone harvesting provides less stem cells count than tibial bone marrow harvesting.