Aim

To identify patterns in referral and the management pathway of patients with primary bone tumours of the spine referred to the Orthopaedic Spine Unit in order to recommend ways to improve the service.

Patients with peripheral primary bone tumours are often identified and referred at an early stage to a regional tumour service according to established guidelines. In patients with primary bone tumours of the spine, however, the definitive management or outcome of such patients is being prejudiced by preliminary intervention from non-specialist services prior to their referral.

Objective: To audit the standards of management of patients with primary bone tumours of the spine referred to a regional tumour service.

Retrospective review of case notes and radiology.

Subjects: Patients with primary bone tumour of the spine managed at the Orthopaedic Spine Unit with the Regional Bone Tumour Service in Newcastle Upon Tyne Hospitals NHS Trust.

Referral to tumour service, prior intervention, operative treatment, survival, factors affecting definitive management

31 of 39 (16 benign, 23 malignant) patients were initially referred from primary care to services other than the regional tumour service, most commonly neurosurgery (11/39) and paediatric oncology (4/39). Seven of 39 of these patients had undergone interventions prior to their referral to the tumour service, which may have negatively impacted their definitive management or curative surgery.

These tumours present complex issues regarding their definitive management to optimise outcome. Closer links between departments are required to enable the multidisciplinary management of primary bone tumours of the spine. Prior surgical intervention may compromise cure. Those involved in their management should be encouraged to liaise with their regional bone tumour service to improve outcome.

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%.

Purpose of Study: Literature suggests that decompression of Chiari malformation for syrinx may influence the need for surgical correction of scoliosis: we therefore wished to review the clinical presentation, indications for surgery, complications and requirement for scoliosis correction after foramen magnum decompression in patients with syrinx, secondary to Chiari malformation.

Methods: A retrospective review of the available clinical information including clinic letters, case notes and radiology.

Results: 9 patients were identified. (Age range 4–16) 8 patients had progressive curves.

Neurological symptoms: 2 patients significant, 4 insignificant, 3 none.

Of 9 patients, 1 has not had surgery.

8 patients have had foramen magnum decompressions (+/− laminectomy, +/− duroplasty).

Complications: 1 patient required revision surgery for a radiculopathy > 1year post first operation: this patient required prolonged ventilation for MRSA chest sepsis. 1 patient developed a symptomatic pseudomeningocoele requiring lumbar drainage. All patients had improvement of neurological symptoms.

Of 8 patients having a foramen magnum decompression, 5 required scoliosis correction and 3 did not.

Conclusions: Foramen magnum decompression can relieve neurological symptoms in this cohort of patients.3 of 8 (38%) patients avoided scoliosis correction after decompression and decompression may therefore influence curve progression.

Ethics approval: Not applicable

Interest Statement: None

Background: Selective lumbar nerve root blocks (SLNRB) are widely used as a diagnostic tool. The usefulness of this technique depends on the ability to accurately infiltrate the desired nerve root without blocking the traversing nerve root to the next level. The aim of this retrospective study was to ascertain the accuracy of SLNRB’s in adult deformity.

Method: 30 SLNRB’s were performed by one surgeon on patients with adult deformity.Pre-operative AP + lateral lumbar films were used to quantify the degree of deformity using the Schwab grading system. An AP fluoroscopic film was taken and analysed to determine the flow of injectate in relation to pedicle anatomy. The results were analysed to determine the accuracy of SLN-RB’s in adult deformity.

Results: Of the 30 patients with deformity 17 needle tips were positioned lateral to the middle third of the pedicle and 13 under the middle third of the pedicle. Of the 17 needle tips placed laterally 8 (47%) had flow into the nerve root sheath, 6 (35%) into the nerve root sheath + canal and 3 (17%) into the canal alone. Overall accuracy with no epidural spread was 40% compared the published standard of 61%.

Conclusions: The accuracy of SLNRB in adult deformity was significantly less than the published standard in patients without deformity. In addition the accuracy of SLNRB with needle tip position lateral to the pedicle was only 47% compared to 96% in previous studies. The suggestion of this author is that contrast is used in all SLNRB’s in patients with deformity in order to allow accurate clinical interpretation of results.

Introduction: Sniff nasal inspiratory pressure has become a valuable tool in assessing respiratory muscle weakness. Its role in the scoliosis population is still being defined.

Aim: To assess significance of Sniff nasal inspiratory pressure in paediatric patients with scoliosis. Eighty-nine paediatric patients were investigated with SNIP at the time of preoperative assessment for scoliosis surgery from Jan, 2000 to Dec, 2006. Patients were divided into neuromuscular(24) and idiopathic(55). Other causes and revision were excluded(10). SNIP was evaluated with respect to curve pattern and curve degree. This included radiograph and case note review.

The mean SNIP value for the idiopathic and neuromuscular groups was 70cmH2O and 44cmH2O respectively. This was significantly different (P=0.006). The mean cobb angle for idiopathic pattern was 58°. For the neuromuscular group it was 73°. There was no correlation between SNIP value and curve severity in either the idiopathic or neuromuscular group.

SNIP value does not correlate with cobb angle severity. SNIP can differentiate idiopathic from neuromuscular scoliosis. Low SNIP values are found in neuromuscular scoliosis. Its role in non neuromuscular scoliosis does not appear to be significant.

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.

Background: Sniff nasal inspiratory pressure (SNIP) has become a valuable tool in assessing respiratory muscle weakness. Its role in the scoliosis population is still being defined.

Purpose: To assess significance of Sniff nasal inspiratory pressure value in paediatric patients with scoliosis.

Methods: Eighty-nine paediatric patients were investigated with SNIP at the time of preoperative assessment for scoliosis surgery from Jan, 2000 to Dec, 2006. Patients were divided into neuromuscular (24) and idiopathic (55). Other causes and revision were excluded (10). SNIP was evaluated with respect to curve pattern and curve degree. This included radiograph and case note review.

Results: The mean SNIP value for the idiopathic and neuromuscular groups was 70cmH2O and 44cmH2O respectively. This was statistically significantly different (0.006). The mean cobb angle for idiopathic pattern was 58 degree. For the neuromuscular group it was 73 degree. There was no correlation between SNIP value and curve severity in either the idiopathic or neuromuscular group.

Conclusion: SNIP is a valuable test when used in conjunction with vital capacity and overnight oxygen saturation, height, comorbidities in the neuromuscular population. It is a sensitive indicator of respiratory muscle weakness. It does not appear to reflect increasing curve severity. It does not appear relevant in scoliosis without a neuromuscular disorder.

Significance: SNIP combined with vital capacity, overnight oxygen saturation, height and co morbidities can be used to assess severity of neuromuscular scoliosis. SNIP value alone has little relevance.

Background: To evaluate bone mineral density in patients with scoliosis of different causes and compare it to the expected values for the age, gender and body mass.

Methods: A Prospective, observational case series. From October 2003 to December 2004, Bone Mineral Density (BMD) of patients with different types of Scoliosis was recorded. Patients listed for corrective spinal surgery in our institute were included in the study (Total of 68 patients). BMD on lumbar spine and whole body was measured by DXA scan and recorded in form of Z-scores. Z-scores = number of Standard Deviations (SD) above or below age matched norms; it is age and gender specific standard deviation scores. Data collected using the same DXA scan equipment and software.

There were 29 patients with Adolescent Idiopathic Scoliosis and 7 patients with congenital or infantile scoliosis. Z-scores from patients with neuromuscular scoliosis also included, 10 patients with cerebral palsy and 11 with muscular dystrophies (mainly Duchenne MD). There were also 3 patients with Neurofbromatosis and 8 patients with other conditions (miscellaneous). Outcome measures were bone mineral density in patients with different types of scoliosis in form of Z-scores.

Results: Bone mineral density was significantly lower than normal for the age, gender and body mass in all patients with neuromuscular scoliosis; whole body z-score in group with cerebral palsy was −1.00 and −1.30 in muscular dystrophies group. Lumbar spine BMD was even lower in lumbar spine, mean z-score, – 4.51 in cerebral palsy and −2.36 in muscular dystrophies (mainly Duchenne MD). In idiopathic Scoliosis group mean BMD was markedly lower than normal for the age, gender and body mass, mean z-score = – 1.87, however whole body BMD was within the normal range, mean z-score = +0.124. Similar results were found in congenital and infantile scoliosis group, mean lumber z-score= – 1.36 and whole body z-score, – 0.30. In patients with neurofibromatosis, there were low BMD on spine, mean z-score was −1.19 while whole body z-score was + 0.19. In group of patients with other miscellaneous causes of scoliosis or syndromic scoliosis lumbar mean z-score= −2.22 and whole body mean z-score was −1.67.

Conclusion: This study showed that BMD on spine was lower than normal for the age, gender and body mass in all patients with scoliosis and the condition was even worse in neuromuscular and sydromic scoliosis. There was no correlation between spine BMD and whole body BMD. Spine BMD was lower than normal in almost all patients even when whole body BMD was within normal range. Thus we believe that DXA scan is a useful adjunct in the preoperative assessment of scoliotic patients prior to spinal surgery.

Introduction: Chance fractures in children are rare the mechanism of injury is a flexion-distraction inertial force created during a motor vehicle accident when wearing a two-point seat belt or lap belt. High velocity paediatric Chance fractures are frequently associated with intra-abdominal injuries, although this may not be appreciated at the time of initial presentation.

Methods: The cases of two brothers who sustained Chance fractures with complete neurological deficits and intra-abdominal injuries from a motor vehicle accident are presented.

Results: The two brothers were rear seat passengers in car involved in a head-on collision with a tree. They were both wearing three point seat belts but had removed the chest straps, thus effectively converting them to a two-point harness.

Case 1. Boy age 3 years 10 months sustained a bony Chance fracture through the L3 vertebrae with a complete neurological deficit at the L1 level. There was an associated closed head injury and severe abdominal bruising. He underwent a CT scan of his abdomen on day of admission and posterior stabilisation of the spinal fracture on day 4. Seven days post-admission he was diagnosed with pancreatitis. He continued to have abdominal pain and vomiting. Further repeat abdominal CT scans, ultrasound examinations and abdominal contrast studies were performed. Ten weeks following admission he underwent laparotomy and a section of ischaemic small bowel was removed.

Case 2. Boy age 2 years 8 months presented with a ligamentous Chance fracture of L2 / L3 with a complete neurological deficit at T12. He had a closed head injury and severe abdominal bruising. He underwent CT scan on the day of admission and a diagnostic peritoneal tap on day two with aspiration of straw coloured fluid. The spinal fracture was stabilised 10 days post-admission with posterior instrumentation. On day 14 he underwent a laparoscopy and subsequent laparotomy with drainage of an abscess secondary to a perforated caecum.

Discussion: Chance fractures or flexion-distraction fractures of the spine are rare occurrences in children with few cases reported. They represent severe trauma and are often related to the wearing of two-point seat belt fixation. There is a high associated incidence of abdominal injuries which may be difficult to diagnose. The authors support the view of Beaunoyer¹ that a diagnostic laparoscopy or laparotomy should be considered strongly in patients with lumbar Chance fractures. Abdominal bruising and neurological defi cit are cardinal signs, reflecting severe trauma.

Introduction: Endoscopic techniques are an established technique for anterior correction and instrumentation of thoracic scoliosis. Deterioration in respiratory function post thoracotomy for has been cited as a disadvantage of anterior approaches and led certain authors to recommend posterior methods¹. Endoscopic techniques may reduce respiratory complications and respiratory compromise in both the short and long term.

Methods: Thirty eight patients, 7 male 31 female, mean age 17.3 yrs (11– 37yrs) have undergone endoscopic scoliosis surgery under the senior author. Indication for surgery was idiopathic scoliosis 36 and an underlying syrinx 2. All patients undergoing endoscopic scoliosis surgery have a standard preoperative assessment including respiratory function tests (RFTs). All patients have been followed up prospectively (mean 15 months, range 3 – 33 months) and standard data recorded. As part of this study we are in the process of performing follow up RFTs on all patients.

Results: Preoperatively no significant respiratory function compromise attributable to the scoliosis has been detected. Mean duration of intercostal drain was 2 days, one patient requiring reinsertion for a recurrent pneumothorax. No other major respiratory complication occurred. On average patients were fully mobile by day five and mean hospital stay was 6 days (4–10 days). Provisional RFTs postoperatively have shown no significant change.

Discussion: Our provisional results indicate that endoscopic scoliosis correction and instrumentation does not lead early respiratory complications or to a significant deterioration in respiratory function of the patient.

Introduction: Thorascopic techniques are an accepted and useful technique for spinal surgery. For certain clinical indications (i.e. thoracic kyphosis), an anterior spinal release followed by a posterior instrumentation may be indicated. The standard technique for a thorascopic anterior release is with the patient in the lateral decubitus position and intubated with a double lumen endotracheal tube (ETT), allowing one lung to be deflated for access to the spine. Placing a double lumen ETT and repositioning the patient before the posterior surgery both add to the duration of surgery. We report our initial experience using standard ETT ventilation, low pressure CO₂ insufflation into the thorax to push the lung away from the operative field, and prone positioning, for thorascopic anterior spinal release, followed by posterior instrumentation. Although previously described for thoracic surgery ^1,2, this technique has not been reported for spinal procedures.

Methods: Five male patients, mean age 15.4yrs (13–17yrs) have undergone thorascopic anterior release and posterior instrumentation as described above. CO₂ insufflation pressure was maintained at 6mm Hg or less. There were three cases of Scheurmanns disease and two progressive kyphosis post laminectomy for intradural tumours. Clinical, operative (including intraoperative physiological measurements) and radiological data have been collected by a retrospective chart review.

Results: In all cases the anterior release was performed successfully followed by posterior instrumentation. Three portals were used in each and three to five levels released. Mean time from start of anaesthesia to completion of anterior release was 140 minutes. Intraoperative physiological measurements (EtCO₂, SaO₂, pulse, BP) remained stable in all cases during the endoscopic procedure. All patients were extubated postoperatively, spent 24 hours in ICU, and remained in hospital for a mean of 9 days (7 – 13 days). There were no significant complications. Mean kyphosis angle improved from 82 degrees preoperatively to 50 degrees postoperatively.

Discussion: Our initial experience with this new technique has been encouraging. There have been concerns regarding the physiological effects of inducing a tension pneumothorax ³, although our results are similar to others who have found low pressure CO₂ insufflation to be safe ². The prone positioning is especially suited for anterior release of a kyphotic spine as it allows the lung to fall away from the spine. Overall we feel this is a useful technique for anterior release of a kyphotic spine.

INTRODUCTION: Thorascopic techniques are an accepted and useful technique for spinal surgery. For certain clinical indications (ie thoracic kyphosis), an anterior spinal release followed by a posterior instrumentation may be indicated. The standard technique for a thorascopic anterior release is with the patient in the lateral decubitus position and intubated with a double lumen endotracheal tube (ETT), allowing one lung to be deflated for access to the spine. Placing a double lumen ETT and repositioning the patient before the posterior surgery both add to the duration of surgery. We report our initial experience using standard ETT ventilation, low pressure CO₂ insufflation into the thorax to push the lung away from the operative field, and prone positioning, for thorascopic anterior spinal release, followed by posterior instrumentation. Although previously described for thoracic surgery ^1,2, this technique has not been reported for spinal procedures.

METHODS: Five male patients, mean age 15.4 years (13–17 years) have undergone thorascopic anterior release and posterior instrumentation as described CO₂ insufflation pressure was maintained at 6 above. mm Hg or less. There were three cases of Scheuermanns disease and two progressive kyphosis post laminectomy for intradural tumours. Clinical, operative (including intraoperative physiological measurements) and radiological data have been collected by a retrospective chart review.

RESULTS: In all cases the anterior release was performed successfully followed by posterior instrumentation. Three portals were used in each and three to five levels released. Mean time from start of anaesthesia to completion of anterior release was 140 minutes. Intra-operative physiological measurements (EtCO₂, SaO₂, pulse, BP) remained stable in all cases during the endoscopic procedure. All patients were extubated post-operatively, spent 24 hours in ICU, and remained in hospital for a mean of nine days (7 – 13 days). There were no significant complications. Mean kyphosis angle improved from 82 degrees pre-operatively to 50 degrees postoperatively.

DISCUSSION: Our initial experience with this new technique has been encouraging. There have been concerns regarding the physiological effects of inducing a tension pneumothorax³, although our results are similar to others who have found low pressure CO₂ insufflation to be safe². The prone positioning is especially suited for anterior release of a kyphotic spine as it allows the lung to fall away from the spine. Overall we feel this is a useful technique for anterior release of a kyphotic spine.

INTRODUCTION: Endoscopic techniques are an established technique for anterior correction and instrumentation of thoracic scoliosis. Deterioration in respiratory function post thoracotomy has been cited as a disadvantage of anterior approaches and led certain authors to recommend posterior methods¹. Endoscopic techniques may reduce respiratory complications and respiratory compromise in both the short and long term.

METHODS: Thirty eight patients, seven male 31 female, mean age 17.3 years (11– 37 years) have undergone endoscopic scoliosis surgery under the senior author. Indication for surgery was idiopathic scoliosis 36 and an underlying syrinx 2. All patients undergoing endoscopic scoliosis surgery have a standard pre-operative assessment including respiratory function tests (RFTs). All patients have been followed up prospectively (mean 15 months, range 3 – 33 months) and standard data recorded. As part of this study we are in the process of performing follow up RFTs on all patients.

RESULTS: Pre-operatively no significant respiratory function compromise attributable to the scoliosis has been detected. Mean duration of intercostal drain was two days, one patient requiring reinsertion for a recurrent pneumothorax. No other major respiratory complication occurred. On average patients were fully mobile by day five and mean hospital stay was six days (4–10 days). Provisional RFTs post-operatively have shown no significant change.

DISCUSSION: Our provisional results indicate that endoscopic scoliosis correction and instrumentation do not lead to early respiratory complications or to a significant deterioration in respiratory function of the patient.

The National Institute for Clinical Excellence (NICE), in its “Guidance on the Selection of Prostheses for Primary Total Hip Replacement”, states that a revision rate of 10% or less at ten years should be regarded as the “benchmark” in the selection of prostheses for primary Total Hip Replacement (THR). This paper presents the results of such a study for primary Charnley THR. Methods: All patients undergoing primary Charnley THR during 1990 were prospectively registered with the Trent Regional Arthroplasty Study (TRAS). During 1990, 1198 Charnley THRs were performed on 1152 patients, under the care of 56 consultants, in 18 National Health Service and 6 private hospitals. The cohort contains 39.0% male and 61.0% female patients, with an average age at operation of 69.1years (21–103 years), 19.1% being less than 60 years. At 10 years all surviving patients at 5 years were registered with the ONS to ascertain living patients. These patients were contacted by letter to determine whether or not their THR had been revised. The status of the THR, for non-responding patients, was determined by contacting the patient’s GP through the Contractor Services Agency (CSA). The endpoint was defined as revision surgery to replace an original implant component. Results: At 10 years, the recipients of 438 THRs had died. The recipients of 89 THRs did not respond to the questionnaire at ten years. Implant status at ten years, in living patients was known for 671 of 760 (88.3%) THRs. The ten-year crude revision rate was 44 out of 1198 (3.7%) and cumulative survival rate was 95.5% (95% CI, 93.6% – 96.9%).

Conclusion: This is the first study to assess the survivorship at 10 years for primary Charnley THRs performed in the ‘general setting’ of the NHS as opposed to specialist centres and shows a result well within the NICE benchmark.

To establish whether there were features present on the initial post-operative radiographs of total hip replacements (THR) predictive of aseptic loosening.

Our data was derived from the Trent Regional Arthroplasty Study (TRAS) which is the only hip register of its kind in the country. The TRAS commenced in 1990 and has recorded clinical and operative details of all THRs in the region.

Our current study was concerned with a cohort of grossly loose THRs, identified from the five-year follow up of those patients who had undergone THR in 1990. Our cohort are those which failed specifically due to aseptic loosening and comprises those revised or listed for revision as well as a number of previously undiagnosed cases.

The post-operative radiographs were analysed, recording the following: (1) number, width and location (Gruen zone) of radiolucencies at both cement-bone and cement-prosthesis interfaces; (2) presence of stem-cortex contact; (3) width of the cement mantle in each Gruen zone; and (4) Barrack cementation grade.

Occasionally, if the initial post-operative radiograph was of poor quality, then further information was gained from the next available ones (usually at six weeks) to improve accuracy.

Comparisons were made with 60 control hips randomly generated from the same 1990 cohort but which had not failed.

Chi-squared tests were used to test the probability of obtaining the observed data by chance and odds ratios were calculated to describe relative risk of failure for different risk factors.

Hips with inadequate cementation grades (C and D) had a 9.5 times greater risk of failure compared to those with adequate cementation grades (A and B) [p< 0.0001].

We have demonstrated that the grade of cementation has a major effect on the probability of failure. This emphasises the importance of good cementing, which is particularly relevant in this era of clinical governance where there is greater accountability on the surgeon for adequate performance.

Introduction: The National Institute for Clinical Excellence (NICE), in its “Guidance on the Selection of Prostheses for Primary Total Hip Replacement”, states that a revision rate of 10% or less at ten years should be regarded as the “benchmark” in the selection of prostheses for primary Total Hip Replacement (THR). Furthermore, they state that evidence for this, in relation to a particular prosthesis, should relate to data from a number of centres, obtained via adequately sized, well conducted observational studies, preferably with consecutive patients from non selected populations. Aim: This paper presents the results of such a study for primary Charnley THR. Methods: All patients undergoing primary Charnley THR during 1990 where prospectively registered with the Trent Regional Arthroplasty Study (TRAS). During 1990, 1198 Charnley THRs were performed on 1152 patients, under the care of 56 consultants, in 18 national health service and 6 private hospitals. The cohort contains 39.0 % male and 61.0 % female patients, with an average age at operation of 69.1years (21–103 years). At 10 years all surviving patients at 5 years were registered with the ONS to ascertain living patients. These patients were contacted by letter to determine whether or not their THR had been revised. The status of the THR, for non-responding patients, was determined by contacting the patient’s GP through the Contractor Services Agency (CSA). Survival analysis was performed using life table analysis as described by Armitage and Berry and the endpoint was defined as revision surgery to replace an original implant component. Results: At 10 years, the recipients of 246 THRs had died. The recipients of 86 THRs did not respond to the questionnaire at ten years. There was no follow–up data on 42 implants at both 5 and 10 years intervals. Thus, implant status at five or ten years, in living patients was known for 910 of 952 (95.6%) THRs. The ten-year crude revision rate was 43 out of 1198 (3.59%) and cumulative survival rate was 95.4% (95% CI, 93.2% – 96.9%). Conclusion: This is the first study to assess the survivorship at 10 years for primary Charnley THRs performed in the “general setting“ of the NHS as opposed to specialist centres and shows a result well within the NICE benchmark.