THE MORPHOLOGY OF THE OSTEO-FIBROUS CANAL FOR THE PASSING OF THE POSTERIOR RAMUS OF THE LUMBAR NERVE WITH SPECIAL REFERENCE TO ITS CLINICAL SIGNIFICANCE / 解剖学报

ABSTRACT

1. 40 cadavers were dissected in order to observe the position, formation and morphology of the osteo-fibrous canal (400 canals) of the posterior rami of the lumbar spinal nerves.2. The average lengths of the osteo-fibrous canals for the posterior ramus of the lumbar nerves in both sexes are L_1 4.88mm, L_2 4.71 mm, L_3 4.61 mm, L_4 4.57mm, L_5 4.39 mm.3. The average longitudinal diameter of the outlets of the osteo-fibrous canals of the posterior rami of the lumbar nerves in both sexes are L_1 6.38mm, L_2 6.73 mm, L_3 6.34mm, L_4 5.75mm, L_5 2.61mm.The average transverse diameters of the outlets of the osteo-fibrous canals of the posterior rami of the lumbar nerves in both sexes are L_1 2.69mm, L_2 2.66mm, L_3 2.68mm, L_4 3.14mm, L_5 2.06mm.4. The shapes of the outlets of the osteo-fibrous canals of the posterior rami of lumbar nerves may be classified into four types nearly circular 64.75% (259 sides); approximately ellipsoid 30.25% (121 sides); nearly triangular 3.00% (12 sides); nearly oblate 2.00% (8 sides).5. 320 inter-transverse ligaments were observed and measured.6. There was always an iliolumbar ligament interposed between L_5 and S_1.7. Further more, the authors discussed the relationship between the morphology of the nerves and the osteo-fibrous canals in connection with the possible causes of low back pain.