Download Six Lumbar Vertebrae: A Case Study

Six Lumbar Vertebrae: A Case Study
Thomas Findley MD PhD VA New Jersey Health Care System, East Orange NJ and UMDNJ-New Jersey
Medical School, Newark NJ. [email protected] 973 676 1000 x 2713
20% of humans show anatomic variations in nerves (median-ulnar anastomosis in both forearm and hand [5]),
muscles (pectoralis abdominis [6]) or vertebrae (extra lumbar and thoracic [1]). While there is variation in
numbers of thoracic vertebrae (9 to 23) across species, all mammalian species except two have exactly 7
cervical vertebrae [3]. Cervical ribs are found in only 1% of human adults, but they are found in 40-60% of
fetuses with congenital abnormalities, and in children are associated with increased cancer incidence. This is
felt to be caused by an underlying genetic defect which causes abnormal Hox gene expression, that gene
affecting both patterning of the axial skeleton and tumor suppression [2]. Thus there is a very strong selection
against cervical ribs and the associated other congenital abnormalities. The presence of 6 lumbar vertebrae has
been reported many years ago [8], with 3% having 6 lumbar, 10% 4 lumbar, 7% 13 thoracic and 3% 11 thoracic
vertebrae [7]. There is a great deal of variation in the lumbar plexus. Persons with 6 lumbar vertebrae and a
lesion between L5 and L6 can have radicular symptoms at L5, S1, or a combination [4].
CASE: a 39 year old very athletic male presented with left knee and low back pain. Manual therapy,
chiropractic and physical therapy exercises gradually resulted in marked improvement in the knee pain but
persistent back pain radiating to the big toe.
When manual therapy was followed 24 hours
later by chiropractic manipulation, there was
movement felt lower in the spine than
previously, and back pain resolved. Xrays
showed 6 lumbar vertebrae. Review of xrays
of his mother also showed 6 lumbar vertebrae.
CONCLUSION: Anatomic variations in
nerves, muscles and bones are common. Some
have a genetic basis and may be associated
with other changes in body physiology,
including immune function. Knowledge of
common variations assists in planning
treatments.
1.
Asher RJ, Lin KH, Kardjilov N, Hautier L May 2011 Variability and constraint in the mammalian
vertebral column. Journal of Evolutionary Biology 24(5):1080-1090
2.
Bots J, Wijnaendts LCD, Delen S, Van Dongen S, Heikinheimo K, Galis F Sep 2011 Analysis of
cervical ribs in a series of human fetuses. Journal of Anatomy 219(3):403-409
3.
Galis F, Van Dooren TJM, Feuth JD, Metz JAJ, Witkam A, Ruinard S, et al. Dec 2006 Extreme
selection in humans against homeotic transformations of cervical vertebrae. Evolution 60(12):2643-2654
4.
Kottlors M, Glocker FX Mar 2010 Dermatomyotomal supply in patients with variations in the number
of lumbar vertebrae. Journal of Neurosurgery Spine 12(3):314-319
5.
Loukas M, Bellary SS, Tubbs RS, Shoja MM, Cohen Gadol AA Mar 2011 Deep palmar
communications between the ulnar and median nerves. Clinical Anatomy 24(2):197-201
6.
Oxnard CE, Franklin D 2008 Ghosts of the past II: muscles and fasciae in the primate forelimb domain.
Folia Primatologica 79(6):441-457
7.
Pilbeam D May 15 2004 The anthropoid postcranial axial skeleton: comments on development,
variation, and evolution. Journal of Experimental Zoology Part B Molecular & Developmental Evolution
302(3):241-267
8.
Webber R 1956 The lumbar nerves in a body with six lumbar vertebrae. Anat rec 126:123-126