Percutaneous radiofrequency facet joint denervation (RFJD) has been used increasingly since being described by Shealy1 for the non-surgical treatment of chronic low back pain. Extensive literature exists on this technique with a number of randomised control studies suggesting efficacy against Placebo2,3. However, the efficacy and reliability of repeat RFJD for chronic back pain is unknown. A prospective study was carried out on a consecutive series of 57 patients undergoing repeat lumbar RFJD between 2004 &
2006. 57 consecutive patients treated by the senior author (OLO) between April 2004–June 2006 were included in a prospective analysis using a visual analogue score (VAS) and the low back outcome score (LBOS). All 57 participants completed a telephone questionnaire at follow up. There were no complications. At a median average follow up of 14 months overall, clinical outcomes demonstrated moderate improvement in the majority of patients with poor rating at LBOS decreasing from 54.3% pre- to 40.3% post-RFJD. The overall degree of satisfaction was 77.2%. The overall median duration of pain relief was 10 months. Our study suggests that repeat RFJD appears to have reliable and satisfactory results when repeated with most patients reporting a high degree of satisfaction and with the clinical outcome similar to the initial procedure.
STUDY DESIGN: A prospective study of 135 subjects with whiplash injury. OBJECTIVES: To identify factors predictive of prolonged disability following whiplash injury. SUMMARY OF BACKGROUND DATA: Although subjects with whiplash associated disorders lack demonstrable physical injury, many exhibit prolonged disability. Disability appears unrelated to the severity of the collision. METHODS: 147 subjects with recent whiplash injury were interviewed for putative risk factors for disability. 135 were re-interviewed 12 months later to assess degree of duration of disability. Bi-variate and multi-variate analyses were undertaken to measure the association between putative risk factors and measures of outcome. RESULTS: The bodily pain score and role emotional scores of the SF-36 health questionnaire showed a consistent significant positive association with better outcomes. After adjustment for bodily pain score and role emotional scores, consulting a lawyer was associated with less improvement in NPOS (p<
0.01) after one year, but there was no significant association with rate of return to work. The degree of damage to the vehicle was not a predictor of outcome. CONCLUSIONS: SF-36 scores for bodily pain and role emotional are useful means of identifying subjects at risk of prolonged disability. The findings support the implementation of an insurance system designed to minimise litigation.
Disc degeneration in the human spine is characterised by progressive fraying and dehydration of the nucleus pulposus associated with formation of clefts within the annulus fibrosus. These have been classified on the basis of autopsy studies into radiating, circumferential and peripheral tears (rim lesions). Outer tears allow neovascularisation of the outer third of the annulus fibrosus and ingrowth of nerve fibres. Correlation with discographic findings had suggested the relevance of peripheral defects in the pathogenesis of discogenic pain. Outer annular tears are likely to be linked to tensile strain onto the collagen fibres and, therefore, may have a mechanical aetiology. In the animal model, peripheral tears of the outer annulus were proven to induce degenerative changes within the inner annulus and the nucleus pulposus. The increased understanding of the role of discrete peripheral defects of the annulus in discogenic pain may support the potential therapeutic effects of thermal treatment using radiofrequency waves and specially designed probes. At present, however, no in vivo studies have been able to demonstrate healing of outer annulus defects and reversibility of mechanical lesions to the intervertebral discs by thermal therapy. While it is highly likely that discrete defects of the outer annulus may be responsible for acute episodes of self-limiting low back pain, it is unclear if annular pathology may be as relevant for chronic disabling back pain. Recent studies using discography and other semi-invasive techniques have suggested that the main discriminating factors between benign, self limiting and chronic disabling back pain may not be anatomical but psycho-social. The challenge remains, in the 21st Century as in the past, to devise appropriate strategies that may lessen the socio-economic burden of back pain. Surgery, however, is highly unlikely to play a significant role in the future.
Surgery for back pain remains highly controversial in view of the significant complication rate and the low likelihood of a successful clinical outcome. Over the last few years, titanium and carbon fibre interbody implants have been used to stabilise spinal motion segments following sub-total removal of disc tissue. These implants offer the theoretical advantage of immediate stabilisation, avoidance of late collapse and prevention of loss of correction of pre-operative deformity in combination with other types of segmental instrumentation such as pedicle screws. Recent long term studies have suggested the possibility of late loosening, implant migration and recurrence of segmental deformity. A recent prospective long term study of titanium cylindrical implants for lumbar degenerative disc disease has indicated that in the presence of multi-level disease, pre-existing olisthesis and levels proximal to the lumbosacral segment, the use of supplementary pedicle screw fixation is required. It appears, however, that despite improved radiological results, the use of interbody cages may not lead to superior functional outcomes when the surgery is carried out for non-specific low back pain.
We studied 135 lumbar discs from 27 spines removed post-mortem from subjects of an average age of 31.5 years. Defects of the annulus fibrosus were classified as peripheral, circumferential or radiating; the nucleus pulposus as normal, moderately or severely degenerate. Peripheral tears were more frequent in the anterior annulus, except in the L5-S1 disc. Circumferential tears were equally distributed between the anterior and the posterior annulus. Almost all the radiating tears were in the posterior annulus, and closely related to the presence of severe nuclear degeneration. Histology suggested that peripheral tears were due to trauma rather than biochemical degradation, and that they developed independently of nuclear degeneration. The association of peripheral annular lesions with low back pain is uncertain but our study suggests that they may have a role in the pathogenesis of discogenic pain.
We attempted to correlate the findings of MRI and discography in patients with low back pain, examining 108 lumbar intervertebral discs in 33 consecutive patients. MRI results were assessed from the intensity and shape of the signal obtained from the central part of the disc. Discography was classified according to the pattern of contrast material, the pressure accepted and the pain reproduced. All discs which were abnormal on MRI had altered patterns on discography, but 18 of the 60 discs with normal MRI had abnormal discograms. Of 39 asymptomatic discs, 33 had normal MRI signals and 24 had normal discograms. None of the 15 discs showing severe degeneration on MRI sustained high levels of intradiscal pressure, but only six of the 60 discs giving normal MRI had low pressure. With current techniques, discography is more accurate than MRI for the detection of annular pathology: a normal MRI does not exclude significant changes in the peripheral structure of the intervertebral disc which can produce low back pain.
Discitis after discography is due to bacterial penetration into the intervertebral disc by a contaminated needle and has an incidence of 1% to 4%. We have examined the prophylactic role of cephazolin administered at the time of discography. An experimental study in sheep using radiographic contrast containing Staphylococcus epidermidis showed that either adding the antibiotic to the intradiscal suspension or giving it intravenously 30 minutes before intradiscal inoculation of bacteria prevented any radiographic, macroscopic or histological signs of discitis; all the intervertebral disc cultures were negative. In a prospective clinical study of 127 consecutive patients having lumbar discography, the injected contrast contained cephazolin 1 mg per ml. None of the patients developed clinical or radiographic signs of discitis. We recommend the use of a suitable broad spectrum antibiotic in a single prophylactic dose whenever the intervertebral disc is entered.
Infection after intradiscal injections has been recognised as a distinct entity, but discitis after discography has often been attributed to an aseptic process or a chemical reaction to the contrast material. We examined the hypothesis that discitis after discography is always due to infection, and report a clinical review and an experimental study. Part I. We reviewed the case records and radiographs of 432 patients who had undergone lumbar discography. When an 18-gauge needle without a stilette had been used, discitis was diagnosed in 2.7% of 222 patients but stiletted needles and a two-needle technique at each level reduced the incidence to 0.7%. Seven patients with discitis after discography had undergone anterior discectomy and fusion; in them the histopathological findings were of a chronic inflammatory response. Bacteria were isolated from the discs of three of the four patients who had open biopsy less than six weeks from the time of discography. These findings suggest that bacteria were initiators rather than promoters of the response. Part II. Multiple level lumbar discography was carried out in mature sheep, injecting contrast material with or without various concentrations of bacteria. Radiographs were taken and the discs and end-plates were examined histologically and cultured for bacteria at intervals after injection. None of the controls showed any evidence of discitis but all sheep injected with bacteria had typical radiological and histopathological changes by six weeks, though cultures were almost all negative. However, at one and two weeks after injection, but usually not after three weeks, bacteria could be isolated. We suggest that all cases of discitis after discography are initiated by infection, and that a very strict aseptic technique should be used for all injections into intervertebral discs.
