Comparison of the bone marrow trephine sample quality between OnControl drill system and the Jamshidi needle.

Trephines obtained by either method had similar assessable areas. The OnControl system was associated with more artefact, a finding in line with previous studies. There was no improvement by sampling the trephine from a separate site to the aspirate. Laboratory-based trainees who reviewed marrow morphology produced trephines with better assessable length than those not based in the laboratory.