Purpose

Distinguishing between sequestered disc fragments and tumours remains a diagnostic challenge, but one of paramount importance given the surgical management of these two clinical entities varies dramatically.

Aim: To determine the distribution of pain which can be most reliably attributed to individual lumbo-sacral nerve root compression.

Introduction: Patients are selected for nerve root decompression based on a correlation between symptoms, signs and imaging findings. However, the belief that a given pain may be attributable to a specific nerve root varies widely between surgeons. Some will only consider decompressing a nerve root in the presence of pain radiating in a classical dermatomal distribution whilst others consider nerve root compression to be a cause of back, buttock or thigh pain.

We sought to determine the distribution of pain which significantly improves following decompression of lumbo-sacral nerve roots.

Methods: Data from consecutive patients undergoing lumbo-sacral nerve root decompression between 2002 and 2005 was prospectively analysed. Inclusion criteria were:

uni- or bilateral single level nerve root decompression

For individual nerve roots the distribution of pain described on post-operative pain drawings was sub-tracted from that described on pre-operative pain drawings. This produced a composite pain drawing demonstrating the distribution of pain most reliably improved by decompressing a particular nerve root.

Results: 52 cases fulfilled the inclusion criteria. There were 6 L4, 36 L5 and 17 S1 nerve root decompressions. The distribution of dramatically improved pain following nerve root decompression did not follow the classic dermatomal patterns described in standard text books.

Conclusions:

Pain as a consequence of lumbo-sacral nerve root compression does not appear to be restricted to classical dermatomal distributions.

Aim: To determine any difference which may exist between the interpretation of nerve root compression demonstrated by an MRI scan as assessed by a radiologist compared to a spinal surgeon.

Introduction: There are a few standardized criteria for attempting to quantify the degree of lumbosacral nerve root compression demonstrated by radiological investigations. However, these are not validated and are not commonly employed. It is possible that the interpretation of films by surgeons is different to that by radiologists. If this is the case it could have important consequences, particularly if potential surgical targets are not recognised. We sought to investigate this potential discrepancy.

Method: Data from consecutive patients undergoing lumbosacral nerve root decompression, by a single surgeon, between 2002 and 2005 was prospectively analysed. Inclusion criteria were:

uni- or bilateral single level nerve root decompression

The MRI report of these patients was then scrutinised to see if the decompressed nerve root had been reported as significantly compressed on the pre-operative scan.

Results: Only 75 % of films had a formal radiological report. Of reported films 22% had not reported the surgical target which rose to 33% for L5 nerve root compression.

Conclusion: Consideration needs to be given to the potential placebo effect of surgery, the nature of the compressive pathology, the clinical details supplied to the radiologist and how the surgical decision making was made.

However, in this sample a large minority of MRIs had no formal report. Of those that were reported, there was underreporting of potential surgical targets by radiologists. This implies that there could be a high incidence of false negative MRI reporting with potentially treatable conditions being unrecognised.