title: Evidence for juvenile disc herniation in a homo erectus boy skeleton.
abstract: METHODS
  An analysis and differential diagnosis of bony alterations in the lower lumbar vertebrae of a Homo erectus boy skeleton.
  
  
  OBJECTIVE
  To analyze low back problems during early human evolution.
  
  
  BACKGROUND
  Back problems in modern humans are often attributed to our upright, bipedal locomotion that is thought to place huge mechanical stresses on the vertebral column. However, little is known of this situation during the course of human evolution.
  
  
  METHODS
  We analyzed the lower lumbar spine of the most complete early hominid skeleton, the 1.5-million-year-old Homo erectus boy KNM-WT 15000 from Nariokotome, Kenya, who died at an age of approximately 8 years. We use bony alterations as indirect evidence for disc disease in the absence of soft tissue.
  
  
  RESULTS
  We describe an extensive osteophytic anterior curved remodeling of the left superior articular process of L5 and formation of a new joint at the underside of the left pedicle of L4. This indicates collisional facet joint subluxation, most likely as the result of juvenile traumatic disc herniation.
  
  
  CONCLUSIONS
  This indirect evidence of possible juvenile disc herniation in a Homo erectus boy skeleton represents the earliest known case of this typical human ailment that is intricately linked to upright bipedalism. The extensive bony remodeling of the articular processes of L4 and L5 suggests that the disc herniation occurred several months before his death. Disabling backache and recurrent sciatica might have, at least, temporarily restricted his daily activities, which indicates advanced social care and nursing in early Homo. We hypothesize that the early Homo intervertebral discs were more vulnerable to injury compared with modern humans because of a relatively small vertebral cross-sectional area.
authors.affiliation: Centre for Evolutionary Medicine, Department of Anatomy, University of Zuerich, Winterthurerstrasse, Zuerich, Switzerland. Martinfelix.Haeusler@uzh.ch
authors.forename: Martin
authors.initials: M
authors.lastname: Haeusler
authors.forename: Regula
authors.initials: R
authors.lastname: Schiess
authors.forename: Thomas
authors.initials: T
authors.lastname: Boeni
mesh_terms: D000818:Animals; D002648:Child; D003937:Diagnosis, Differential; D005580:Fossils; D015186:Hominidae; D006801:Humans; D007403:Intervertebral Disc / Q000473:pathology*; D007405:Intervertebral Disc Displacement / Q000175:diagnosis*; D007630:Kenya; D008159:Lumbar Vertebrae / Q000473:pathology*; D008297:Male