Schmorl's nodes in an American military population: frequency, formation, and etiology.

This research investigates the frequency of Schmorl's nodes in differing populations, with new data from a skeletal sample from the Central Identification Laboratory (CIL) at the Joint Prisoner of War/Missing in Action Accounting Command, while also reviewing the etiology of Schmorl's node formation. Processes implicated in Schmorl's node formation include trauma, old age, disease, intrinsic abnormalities, and biomechanical factors, and they correlate with Schmorl's node formation to varying degrees. A survey of research from the anthropology and medical literature revealed Schmorl's node population frequencies ranging from 8 to 80%. The current study consists of two samples, one derived from CIL case reports and one analyzing skeletal remains. The case report sample yielded a Schmorl's node frequency of 19.8%. The examined sample yielded a frequency of 73.7%. The disparate frequencies reported are likely due mainly to differences in completeness and observability. It is likely that trauma was a major factor in the formation of Schmorl's nodes in the CIL study.