MRI findings of disc protrusion , nerve root displacement or compression , disc degeneration , and high intensity zone are all associated with LBP , but individually , none of these abnormalities provides a strong indication that LBP is attributable to underlying pathology .
This limits their value in refining epidemiological case definitions for LBP
OBJECTIVE to assess how confidently  low back pain ( LBP ) can be attributed to abnormalities on magnetic resonance imaging ( MRI ) , and thereby explore the potential value of MRI abnormalities in refining case definition for mechanical LBP in epidemiological research .
SUMMARY OF BACKGROUND DATA most epidemiological studies of mechanical LBP have defined cases only by reported symptoms , but it is possible that the potency of causes differs depending on whether there is demonstrable underlying spinal pathology .
Low Back Pain on Passive Straight Leg Raising: The Anterior Theca as a Source of Pain
Study Design . A prospect i ve clinical and radiologic investigation of two groups of patients presenting with either acute back pain only or acute leg pain only , yet similar restriction in straight leg raising ( SLR ) . Objectives . To highlight a group of patients presenting with acute low back pain only , yet a restricted SLR normally associated with leg pain ( sciatica ) caused by a posterolateral disc prolapse . To determine the anatomic source of the pain in the low back pain only group . Summary of Background Data . A restricted SLR is commonly associated with leg pain ( sciatica ) due to compression of a nerve root by an intervertebral disc prolapse . Previous studies investigating pain patterns on SLR have suggested that central disc prolapses tend to induce back pain whereas the more lateral prolapses induce leg pain . Such research work has involved patients presenting with typical sciatic pain investigated by myelography and undergoing decompressive surgery . There are no studies specifically investigating patients presenting with low back pain only and reduced SLR . Methods . Two groups of patients , one with acute low back pain only and one with acute leg pain only , yet showing similar restriction in SLR underwent MR imaging .  The scans were review ed “ blind ” by an experienced spinal radiologist and imaging features recorded according to a detailed protocol . The MR findings were then compared . Results . Significant disc prolapses were seen equally in both groups . The disc prolapses in the back pain only group were more likely to be central , smaller , to compress the theca only , and to be at a higher lumbar level as compared with the leg pain only group . Conclusions . Acute low back pain associated with significant restriction in SLR is likely to be caused by a disc prolapse compressing the anterior theca
MRI findings of disc protrusion , nerve root displacement or compression , disc degeneration , and high intensity zone are all associated with LBP , but individually , none of these abnormalities provides a strong indication that LBP is attributable to underlying pathology .
This limits their value in refining epidemiological case definitions for LBP
OBJECTIVE to assess how confidently  low back pain ( LBP ) can be attributed to abnormalities on magnetic resonance imaging ( MRI ) , and thereby explore the potential value of MRI abnormalities in refining case definition for mechanical LBP in epidemiological research .
SUMMARY OF BACKGROUND DATA most epidemiological studies of mechanical LBP have defined cases only by reported symptoms , but it is possible that the potency of causes differs depending on whether there is demonstrable underlying spinal pathology .