anatomical study of the lumbosacral ligament

ABSTRACT

The structure of the human lumbosacral region should be studied extensively in attempts to diagnose possible anatomical sources of low back pain. Only few studies have examined the correlation between the disposition of the ligaments at the level of the fifth lumbar intervertebral foramen and nerve root entrapment. This work was carried out to investigate the anatomical attachment, length and width of the lumbosacral ligament and to determine if the ligament could cause compression of the 5[th] lumbar nerve. In this study, fifteen cadavers [thirty specimens] were dissected and the position and relations of the lumbosacral ligament were examined bilaterally. The ligament was found to be present in all the specimens. It extends from the transverse process of the 5[th] lumbar vertebra to the ala of sacrum. The ligament was found to pass anterior to the 5[th] lumbar nerve in thirteen specimens out of thirty [43.3%]. This may cause compression of the nerve at that site. The measurements of the ligament were done with a digital sliding caliper. The 5[th] lumbar nerves passing deep to the ligament were examined histologically to see signs of compression of the nerve. The compressed nerves showed increased thickness of endoneurial perineurial and epineurial connective tissue. These results are of interest to the clinician whose patient presents with L5 root signs and with a myelogram or computed tomographic scan which do not show any abnormality. The possibility of extra-foraminal compression must be considered as a possible source of the clinical signs