Following the implementation of the Ionising Radiations (Medical Exposure) Regulations Act 2000 and recommendation from International Commission on Radiological Protection (ICRP), the establishment of diagnostic reference levels (DRLs) for all radiological examinations became mandatory. There are no recommended or published standards or national dosage guidelines in the UK of diagnostic reference levels available for fluoroscopy-guided diagnostic and therapeutic spinal procedures. The aim of this study is to establish reference dose area product (DAP) levels for the diagnostic spinal procedures requiring fluoroscopy as a basis for setting DRLs.

All patient data consisted of diagnostic spinal procedures done in 2009 at Newcastle General Hospital under care of 4 spinal surgeons. Radiation data were collected on specific type of the procedure, DAP and screening time. Nerve root blocks, facet joint blocks and facet joint rhizolysis were included for data collection and analysis for this study. The third-quartile values were used to establish the DRLs.

There were 387 nerve root blocks with a mean exposure per injection 171.3 cGycm² (range, 3.0 to 2029.1; third quartile 209.4). Facet joint injections were 669 at a mean radiation dose 41.3 cGycm² (range, 1.9 to 541.0; third quartile 48.9). In a total 430 facet joint rhizolysis, the mean exposure was 44.4 cGycm² (range, 7.7 to 154.5; third quartile 58.4). The mean screening times were 36.7s (range, 0.4-281s; third quartile 41s) for nerve root blocks, mean 11.2s (range, 1.8-37s, third quartile 13.3s) for single facet joint block and mean 14.6s (range, 0.1-162s, third quartile 15.1s) for single facet rhizolysis.

We found the third-quartile values for setting DRLs for single level nerve root block, single facet joint block and single facet joint rhizolysis to be 209.4, 48.9 and 58.4 cGycm² respectively. We recommend that all spinal units in the UK should establish their own local DRLs to help in establishing national dosage guidelines for fluoroscopy-guided diagnostic and also therapeutic spinal procedures.

Background: Although needle tip position has been correlated with outcome with respect to pain relief, and to complication rate, to our knowledge, no previous study assesses the location of the needle tip with respect to its ability to isolate injectate around the exiting nerve root without blocking the traversing nerve root to the next caudal level.

Aim: To study the location of injectate when diagnostic selective nerve root blockade is performed.

Method: 87 consecutive selective nerve root blocks performed by a single surgeon were assessed. A consistent surgical technique was utilised. Antero-Posterior fluoroscopy films were analysed to determine the location of injectate in relation to the foraminal and pedicle anatomy. A pro-forma operation note ensured all necessary data was collected prospectively.

Results: Of needle tips positioned lateral to the middle third of the superior pedicle on the AP view, 45 of 51 flowed into the nerve sheath alone, and 6 flowed into both the nerve sheath, and spinal canal. Of these 6, 2 were due to a larger volume of contrast injected, and 2 were due to abnormal anatomy from marked lumbar degenerative scoliosis. Of tips located below the middle third of the pedicle, 2 of 29 flowed into the nerve sheath alone, 2 flowed into the canal alone, and 27 flowed into both. Of those placed medial to zone below the middle third of the pedicle, all seven flowed into the canal only. Analysis using Fisher’s Exact test yielded an extremely statistically significant result, with p < 0.001 comparing needle tip positions in the lateral position with the mid-zone and medial tip positions, and their relationship with injectate reaching the traversing nerve root.

Discussion: For a nerve root block to be truly selective, no injectate must flow past the exiting root to the traversing root. Low volumes of injectate must be placed predictably and accurately. This paper demonstrates the importance of needle tip location in preventing flow beyond the foramen. It is also recommended that contrast be used when significant deformity is present. In cases where there is a therapeutic rather than diagnostic intention, such accuracy is unnecessary. This study does not address the efficacy of the selective nerve root block as a non-operative intervention, nor does it assess the ability of the block to predict operative benefit. It does, however, provide a benchmark for accuracy achievable in patients without significant spinal deformity.

Conclusion: Care must be taken to ensure that the needle tip is positioned lateral to the zone below the middle third of the pedicle if a selective nerve root block is to be used for diagnostic purposes, particularly if there is significant deformity or no contrast is used. In the absence of deformity, however, selective nerve root block may be performed reliably, with a location accuracy of 96%.

Aim: To study the location of injectate when diagnostic selective nerve root blockade is performed.

Method: 87 consecutive selective nerve root blocks performed by a single surgeon were assessed. A consistent surgical technique was utilised for all patients. Antero-Posterior fluoroscopy films were analysed to determine the location of injectate in relation to the foraminal and pedicle anatomy.

Results: Of needle tips positioned lateral to the middle third of the superior pedicle on the AP view, 45 of 51 flowed into the nerve sheath alone, and 6 flowed into both the nerve sheath, and spinal canal. Of these 6, 2 were due to a larger volume of contrast injected, and 2 were due to abnormal anatomy from marked lumbar degenerative scoliosis. Of needle tips located below the middle third of the pedicle, 2 of 29 flowed into the nerve sheath alone, 2 flowed into the canal alone, and 27 flowed into both. Of those placed medial to zone below the middle third of the pedicle, all seven flowed into the canal only.

Conclusion: Care must be taken to ensure that the needle tip is positioned lateral to the zone below the middle third of the pedicle if a selective nerve root block is to be used for diagnostic purposes, particularly if there is significant deformity or no contrast is used. In the absence of deformity, however, selective nerve root block may be performed reliably, with a location accuracy of 96% providing the tip of the needle lies in the lateral position described.

Introduction: Sciatica is the classical indication for decompression of the lumbar nerve roots. However there is a small group of patients who have atypical proximal pain i.e. pain in the groin, buttock and thigh pain without radiation below the knee, and have nerve root compression on the MRI scans. We investigated these patients with nerve root injection (NRI).

Methodology: We retrospectively studied 125-diagnostic NRIs, of these there were 12 patients (7 female & 5 male) with pain in the groin(5), thigh (4), buttock(6) & lower back(9) but no radiating pain below the knee. The MRI scans were reported independently as nerve root compression (11 L5 & 1 S1) by the radiologist. All these 12 patients were offered nerve root injection. The nerve root injection was carried out as described by Herron, under the guidance of image intensifier with bupivacaine and methylprednisolone.

Results: Of these 5 (42%) of them had temporary relief of the symptoms with nerve root injection; all of them underwent flavectomy & facetectomy of the affected nerve root. They were followed for an average duration of 39 months. Three patients were delighted with the result, 1 patient had a pain free period for 3 years then the symptoms recurred and the last patient did not benefit with the surgery.

Conclusion: We conclude that nerve root injection can be an important diagnostic tool in making a surgical decision regarding patients with such atypical symptoms.

Decision to operate for lumbar nerve root compression is usually based on the clinical findings and MRI scan evidence of nerve root compression. Decision-making is difficult in the small subset of patients with atypical pain, pain in the groin, buttock or thigh with L5 and S1 nerve root compression, as evident on the MRI scan. We retrospectively studied 125- diagnostic nerve root injections; of which there were 12 patients who had pain in the groin, thigh or buttock and their MRI scans were reported as nerve root (11 L5 & 1 S1) compression by the radiologist independently. All these 12 patients were subjected to injection of the affected nerve root with bupivacaine and methylprednisolone under the guidance of image intensifier. Of these 5 (42%) of them had temporary relief of the symptoms; and all of them underwent surgical decompression of the affected nerve root. They were followed for an average of 12 months with satisfactory results. This demonstrates the importance of nerve root injections as a diagnostic tool in patients with atypical symptoms with nerve root compression as seen on the MRI scan.

Study Design: A prospective evaluation of 40 consecutive patients with sciatica who had ‘Normal’ MRI scans, were further investigated with Nerve Root Injections (NRI), and subsequent surgery in those who had relief of symptoms.

Objectives: To evaluate the diagnostic value of NRI’s in the presence of normal MRI scans and to assess the aetiology of the sciatica.

Summary of Background Data: Since the advent of MRI scans the use of NRI’s has been in decline as a diagnostic tool. There has been no study in their usefulness when the MRI has been reported as showing no evidence of nerve root compression, and furthermore what the surgical findings were in the patients who went on to exploration.

Methods: 40 Patients with sciatica, of minimal duration of one year, in whom the MRI scan had been reported as showing no evidence of nerve root compression by an independent observer, had diagnostic NRI’s performed. Those patients that had reproduction of and subsequent temporary relief of their sciatica had surgery.

Outcome Measures: Walking distance, Analgesic Requirements, Sleep disturbance and VAS.

Results: Of the 40 patients, 25 had no benefit, 4 patients had permanent relief and 11 had temporary relief. These 11 patients underwent surgery. All patients undergoing surgery were L5 nerve root explorations. In 9 cases the compression was by the ligamentum flavum and in 2 at the foramen. Of the eleven cases operated on 9 had complete relief of symptoms and 2 were unchanged.

Conclusions: MRI scans do not show a cause for sciatica in all patients as it is not a dynamic test. In the presence of a normal MRI scan, NRI’s should be performed.

Decision to operate for lumbar nerve root compression is usually based on the clinical findings and MRI scan evidence of nerve root compression. Decision-making is difficult in the subset of patients with pain in the groin, buttock or thigh with L5 and S1 nerve root compression as evidenced by MRI scan. We retrospectively studied 125- diagnostic nerve root injections, of which there were 12 patients who had pain in the groin, thigh or buttock and their MRI scans were reported as nerve root (11 L5 & 1 S1) compression by the radiologist. All these 12 patients were subjected to injection of the affected nerve root with bupivacaine and methylprednisolone under the guidance of image intensifier. Of these 5 (42%) of them had temporary relief of the symptoms; and all of them underwent surgical decompression of the affected nerve root. They were followed for an average of 12 months with satisfactory results. This demonstrates the importance of nerve root injections as a diagnostic tool in patients with atypical symptoms with a positive MRI scan.

Introduction: The threshold for internal fixation of thoracolumbar junction fractures is controversial. Most authorities would agree that indications would include neurological deficit and severe deformity. The definition of severe deformity many would regard as a kyphus angle of 20° or more and/or compression of more than 50% of the anterior body height. Patients are only assessed on supine films alone. The aim of this study was to ascertain whether weight-bearing films altered the deformity and if so did this subsequently alter management.

Methods: A prospective study of patients who had suffered a fracture of the thoracolumbar junction (T11- L2). All patients who had a neurological deficit or a kyphus angle of greater than 20° and/or greater than 50% anterior body collapse were excluded. Only patients with a deformity less than the above were entered into the study. These patients then had weight-bearing views (standing or sitting) as soon as they had developed trunk control. A kyphus angle of greater than 20° or more than 50% body collapse were used as a criteria for fixation.

Results: 16 patients were entered into the study over a one year period. Five (31% ) of the 16 patients had a significant increase in their deformity on weight-bearing films that caused them to pass the threshold for fixation, and subsequently had surgery .

Conclusion: The authors recommend that weight-bearing views should always be taken on fractures of the thoracolumbar spine if conservative treatment is being considered.