Purpose of the Study

Assessment of long term results of Chemonucleolysis vs. surgery for soft disc herniation

Purpose

To compare the efficacy and safety of balloon kyphoplasty (BKP) to non-surgical management (NSM) over 24 months in patients with acute painful fractures by clinical outcomes and vertebral body kyphosis correction and surgical parameters.

Purpose

Lumbar paraspinal muscle dysfunction and low back pain are strongly correlated. Muscle atrophy is common in LBP and is recognised by MRI scan. Corticosteroid injections and physical rehabilitation programs are advocated for treatment of LBP.

The purpose is to evaluate efficacy of specific lumbar multifidus muscle retraining exercises and perifacet multifidus injections in treatment of Low Back Pain (LBP) and referred leg pain.

Objective

To identify any difference in clinical outcome between Intra-Capsular facet (IF) and Peri-facet (PF) injections in patients with low back pain (LBP). IF and PF joint steroid injections have been used for treatment of LBP with varied reports of pain relief for many years.

Balloon kyphoplasty (BKP) is a minimally invasive treatment for vertebral fractures (VCF) aiming to correct deformity using balloon tamps and bone cement to stabilize the body. Patients with 1 - 3 non-traumatic acute VCF were enrolled within three months of diagnosis and randomly assigned to receive either BKP (N=149) or nonsurgical care (N=151). Follow-up was 2 years.

The mean SF-36 physical component summary (PCS) score improved 5.1 points (95%CI, 2.8-7.4; p<0.0001) more in the kyphoplasty than the nonsurgical group at one month, the primary endpoint of the study.

Kyphoplasty improved the PCS score by an average of 3.0 points (95%CI, 1.6-5.4; p=0.002) during the two-year follow-up. There was a significant interaction between treatment and follow-up time (p=0.003), indicating that the treatment effect over the year is not uniform across follow-up; a result from early improvement that persists in the kyphoplasty group whereas the nonsurgical group shows more incremental improvement over time.

Overall, patients assigned to kyphoplasty also had statistically significant improvements over the two years compared to the control group in global quality of life (EQ-5D), pain relief (VAS), back disability (RMDQ) and days of limited activity (within a two-week period).

There was no statistical significant difference between groups in the number of patients with adverse events or new VCF's over 24 months.

Compared to the control, BKP improved quality of life and reduced back pain and disability and did not increase adverse events including the risk of new vertebral fractures over 2 years.

Assessment of long term results of Chemonucleolysis vs. surgical enucleation in soft disc herniation

From 1982 to 1985, 100 patients with symptomatic disc herniation were randomly allocated to receive either Chemonucleolysis or disc enucleation after all these patients had a trial of conservative treatment for three months.

The outcome of result was measured using MacNab Criteria with the help of

Questionnaire

Assessing the patients in clinic

44 patients out of original 100 patients were followed up in the clinic 25 years later. 24 were from chemonucleolysis group and 20 from the surgical group.

According to MacNab criteria 62.5% had excellent or good results and 25% poor results in chemonucleolysis group and in surgery group 70% had excellent or good results and 10% poor results. Patients with poor result in Chemonucleolysis group consisted of: a) 1 had poor result post TKR, b) 4 were offered surgical enucleation subsequent to failed Chemonucleolysis though they did not seem to benefit from surgery and 1 out of these 4 also had fibromyalgia. c) 1 had poor result after sustaining fracture neck of femur. Poor results in surgical group were due to persistent back pain.

The results at 25 year follow-up have shown no statistically significant difference between the patients treated by either chemonucleolysis or surgery. The added benefit of using the chymopapain injection is that it is of lower cost. Chemonucleolysis should have a wider role in treatment of intervertebral disc herniation.

Background

Vertebral body compression fractures (VCFs) impair quality of life (QOL) and increase patient morbidity and mortality. The international, multicentre, randomised, controlled Fracture Reduction Evaluation (FREE) trial was initiated to compare effectiveness and safety of Balloon kyphoplasty (BKP) to non-surgical management (NSM) for the treatment of acute painful VCFs. We describe the primary endpoint of the ongoing 2-year study.

Purpose: Correlation of clinical outcome of X stop interspinous process decompression in patients with symptomatic lumbar spinal stenosis is made with spinal canal area change on positional MRI.

Method and Results: Clinical outcome was assessed by ZCQ, ODI, SF36 and VAS scores. There is clinically significant improvement if two ZCQ domains improved > threshold or patients were satisfied. Dural sac area was measured standing erect and sitting, neutral, flexion and extension preoperatively and at 2 years. Increased dural sac area was taken as radiological improvement.

Thirty-six patients had MRI at 2 years. Using paired t test we noted statistically significant increase in mean dural sac area in all four positions mentioned above. There was clinical improvement in 26 and some or no improvement in 10 patients. Number with increase in canal cross sectional area was 28 and that with reduced area was 8. Clinical and canal area improvement was seen in 20 (56%) patients and clinical improvement with reduced canal area was seen in 5 (14%). Some or no clinical improvement with canal area improvement occurred in 8 (22%) patients and no significant clinical or canal area improvement in 3 (8%).

Conclusions:

Majority of patients (56%) showed clinical and cross sectional area improvement at 2 years.

Interest statement: Commercial/industry support: Medtronics

Purpose: Correlation of the clinical outcome of X stop interspinous process decompression (IPD) in patients with symptomatic lumbar spinal stenosis (LSS) is made with their preoperative disc heights.

Method: 45 patients, who had clinical follow-up at 2 years, had pre-operative erect positional MRI scans. Clinical outcome was assessed by Zurich Claudication Questionnaire,ODI,SF36 and VAS scores.ZCQ is the most condition specific for LSS and was used. There is clinically significant improvement if two ZCQ domains improved > threshold (SS> 0.46, PF> 0.42, PS< 2.4) or patients were satisfied. Disc heights were measured in the standing erect posture. Osiris 4.17 software program was used for measurements. Statistics used was Chi-Square test with cross tabulation.

Results: There was clinical improvement in 33 and some or no improvement in 12 patients. Overall preoperative range of disc heights was 1.8 to 10.05 mm, median 5.93. Disc height was less than or equal to 5mm in 21 patients and it was > 5 mm in 24 patients.19 patients who had initial disc height of > 5 mm and 14 patients who had disc height of less than or equal to 5 mm had clinically significant improvement. In the group of patients who had some or no improvement the numbers were 5 and 7 respectively. We found a difference between the groups with bigger and smaller preoperative disc heights and a larger proportion of patients with bigger preoperative disc height had better clinical outcome. This difference was not statistically significant, P = 0.350.

Conclusions: The X stop device remains clinically effective at the end of 2 years in the majority of patients. Overall patients who had bigger preoperative disc heights 79% (i.e. 19/24 who had > 5mm initial disc height) had better clinical outcome compared to those with smaller preoperative disc heights.

Interest statement: Commercial/industry support: Medtronics

Background: The X stop interspinous process decompression device has been used effectively in symptomatic lumbar spinal stenosis. It holds the spinal segment in a flexed position maintaining increase in dural sac and foraminal areas.

Aim: To study the effect of X-stop on the lumbar spine kinematics at 24 months post operatively at the instrumented and adjacent levels.

Design: Prospective Observational Study of 48 patients.

Methods: Patients had a positional MRI scan preoperatively, 6 and 24 months post operatively in erect, flexion, extension and neutral positions. Disc heights, endplate angles, segmental and lumbar spine motion were measured at stenosed instrumented and adjacent levels. Osiris 4.17 software program was used for measurements. The data was analysed using paired t test on SPSS ver.15.01.

Results: 48 patients underwent scans preoperatively. At 2 years 40 patients were scanned (3 patients had removal of X stop and 5 were not scanned). Of these, 38 scans were complete. Mean anterior disc height reduced from 7.2 mm to 5.9 mm (p< 0.001) at 24 months at the instrumented level. There were no significant changes in posterior disc height at instrumented or adjacent levels. The mean lumbar spine motion was 22o and 20o (p=0.366) in single level cases and 24.5o and 22.8o (p=0.547) in double level cases preoperatively and at 24 months. There was no significant change in the segmental range of motion at instrumented or adjacent levels.

Conclusion: X-stop device does not significantly alter the kinematics of lumbar spine at instrumented or adjacent levels at 24 months postoperatively.

Purpose: Balloon kyphoplasty (BKP) is a minimally invasive treatment for acute vertebral compression fractures (VCF) that aims both to correct associated vertebral deformity (reduce) and stabilize the fracture by injecting bone cement. We performed the first multicenter randomized trial to assess the effect of BKP.

Method: Patients with 1–3 non-traumatic vertebral compression fractures diagnosed within 3 months were randomly assigned to receive either BKP (N=149) or usual nonsurgical care (NSC) (N=151). Measurements of quality of life, back pain and function, days of disability and bed rest were assessed at baseline, 1, 3, 6 and 12 months.

Results: The primary outcome measure, the difference between groups in change from baseline scores in the physical component summary of the SF-36 questionnaire, improved 3.5 points (95% CI, 1.6 to 5.4; p=0.0004) more in the BKP group when averaged across 12 months of follow-up. Compared with the NSC group, those assigned to BKP also had greater improvement in quality of life and back function throughout 12 months of follow-up as measured by the EuroQol and Roland-Morris scales; a difference of 0.14 points (95% CI, 0.05 to 0.23; p=0.0023) more and 3.2 points (95% CI, 1.7 to 3.8; p< 0.0001) and reported fewer days of limited activity in the previous 2 weeks due to back pain (2.5 fewer days; 95% CI, 1.2 to 3.8; p=0.0001). New radiographically detected vertebral fractures occurred in 41.8% of subjects in the kyphoplasty and 37.8% in the nonsurgical group (4% difference; 95% CI −7.5 to 15.6; p=0.5).

Conclusion: Compared to nonsurgical treatment, balloon kyphoplasty improved multiple measurements of quality of life, back pain and disability that last at least one year after the procedure. No difference is seen between groups in radiographically detected VCF’s (Clinicaltrials.gov number, NCT00211211).

Background: X stop interspinous decompression device has been used effectively in symptomatic patients with lumbar canal stenosis. The positional MRI scanner images patients in the erect weight bearing position and is used here to evaluate the efficacy of the X stop in maintaining increase in dural sac and foraminal areas.

Aim: To assess the clinical effectiveness of X stop in patients with lumbar canal stenosis and measure its effect in decompressing the spinal canal two years postoperatively.

Design: Prospective Observational Study.

Methods: Clinical outcome was assessed by ZCQ, VAS, ODI and SF36 questionnaires. Clinical and radiological outcomes were measured preoperatively and at 2 years. Foraminal area was measured in flexion and extension whereas dural sac area was measured in erect, neutral, flexion and extension. Osiris 4.17 software program was used for the measurements. The data was analysed using paired t test on SPSS ver.15.01.

Results: With ZCQ overall 57% of patients had clinically significant improvement at 24 months. The mean ODI and VAS scores showed improvement. The SF-36 improved in four domains. Radiologically we noted increase in mean dural sac area in all positions. There was a small increase in foraminal areas and statistically significant increase in dural sac areas at 24 months.

Conclusion: The X stop device remains clinically effective at the end of 2 years. It is a relatively less invasive procedure without major complications and can be performed as a day case procedure. X stop maintains increase in dural sac and foraminal areas at 24 months postoperatively.

Introduction: Deep Venous Thrombosis (DVT) and pulmonary embolism (PE) cause significant morbidity and mortality in orthopaedic surgical practice, although the incidence following surgery to the lumbosacral spine is less than following lower limb surgery. Our objective was to compare our rate of thromboembolic complications with those published elsewhere and investigate whether the adoption of additional pharmacological and physical measures had reduced the incidence of clinically evident deep venous thrombosis (DVT) and pulmonary embolism (PE).

Materials and Method: This study was undertaken to investigate the incidence of DVT/PE during the 10 years from 1/1/1985 to 31/12/1994, and then to assess the effectiveness of an anticoagulant policy introduced during 1995 using low dose aspirin or LMH in high risk cases. All records for spinal operations were reviewed for thromboembolic complications by reference to the Scottish Morbidity Record form SMR1. To ensure that all patients were compliant with the policy, data for the whole of 1995 was omitted and the period 1/1/1996 to 31/12/2003 was taken to assess its effectiveness.

Surgery was done with the patient in the kneeling, seated prone position which leaves the abdomen free and avoids venous kinking in the legs.

Results: Records of a total of 1111 lumbar spine operations were performed from 1/1/1985 to 31/12/2004 were reviewed. The overall incidence of thromboembolic complications was 0.29%. A total of 697 operations were performed from 1/1/1985 to 311994 with two cases of DVT and no cases of PE giving thromboembolic complication rate of 0.29%. During the period 1/1/1996 to 31/12/2003, 414 operations resulted in one case of DVT and no cases of PE, a rate 0f 0.24%.

Conclusion: The incidence of thromboembolic complications is low whether or not anticoagulation is used. We believe that the kneeling, seated prone operating position is a significant contributing factor.

Background: Balloon kyphoplasty is a minimally invasive treatment for acute vertebral fractures that aims to reduce and correct vertebral deformity by inserting expandable balloon tamps and then stabilize the body by filling it with bone cement. The effect of balloon kyphoplasty on quality of life has not been tested in a randomized trial.

Methods: Patients with up to 3 non-traumatic acute vertebral compression fractures were enrolled within 3 months of diagnosis and randomly assigned to receive either balloon kyphoplasty (N=149) or usual nonsurgical care (N=151). Measurements of quality of life, back pain and function, and days of disability and bed rest and spine radiographs were assessed through 12 months of follow-up.

Results: Compared with those assigned to nonsurgical care, participants assigned to balloon kyphoplasty had 5.2 points (95% CI, 2.9 to 7.4; p< 0.0001) greater improvement in the physical component of the SF-36 quality of life questionnaire at one month and 1.5 points (95% CI, − 0.8 to 3.8; p=0.2) at twelve months. Those in the balloon kyphoplasty group also had greater improvement in quality of life by the EuroQol questionnaire at one (0.18 points; 95% CI, 0.08 to 0.28; p=0.0003) and twelve months (0.12 points; 95% CI, 0.01 to 0.22; p=0.025) and improved disability by the Roland-Morris scale at one month (4.0 points; 95% CI, 2.6 to 5.5; p< 0.0001) and twelve months (2.6 points; 95% CI, 1.0 to 4.1; p=0.0012). Balloon kyphoplasty patients had less back pain on a 0 to 10-point numeric rating scale at seven days (2.2 points; 95% CI, 1.6 to 2.8; p< 0.0001) and twelve months (0.9 points; 95% CI, 0.3 to 1.5; p=0.0034) and reported fewer days of limited activity at one month (2.9 days per 2 weeks; 95% CI, 1.3 to 4.6; p=0.0004) and twelve months (1.6; 95% CI, − 0.1 to 3.3; p=0.068). Fewer patients assigned to balloon kyphoplasty took pain medications or used walking aids during follow-up. There was no significant difference in the number of patients with adverse events or serious adverse events in the kyphoplasty and nonsurgical groups. New radiographically detected vertebral fractures occurred in 41.8% of subjects in the balloon kyphoplasty and 37.8% in the nonsurgical group (4% difference; 95% CI − 7.5 to 15.6; p=0.5) and were not statistically different.

Conclusion: Compared to nonsurgical treatment, balloon kyphoplasty safely improved quality of life and reduced back pain, disability and the use of pain medications and walking aids. Significant improvements in multiple measurements of quality of life, pain and disability continue for at least 1 year. Balloon kyphoplasty did not increase adverse events including the risk of vertebral fractures (Clinicaltrials.gov number, NCT00211211).

Aim: To measure the effect of X-stop interspinous decompression device on the dural sac and foraminal area at 6 and 24 months post operatively at the instrumented level in patients with symptomatic lumbar canal stenosis.

Design: Prospective Observational Study of 48 patients.

Methods: Patients due to have an X stop procedure were included and had a positional MRI scan preoperatively and 6 & 24 months post operatively. Foraminal area was measured in flexion and extension position whereas dural cross sectional area was measured in erect, neutral, flexion and extension positions. Osiris 4.17 software program was used to measure the canal and foraminal dimensions. The data was analysed using paired t test on SPSS ver.15.01.

Results: Forty-eight patients (25 male and 23 female) underwent scans preoperatively and at six months. Twenty-nine patients had single level and 19 had double level procedures. Three patients had removal of X stop and 5 did not have scan at 24 months leaving 40 patients scanned at 24 months. Of these 38 scans were complete and were included. We noted increase in mean dural sac area in all positions. The mean dural sac area increased from 131 mm2 to 143 mm2 (p=0.144) at 6 months and from 137 mm2 to 202 mm2 (p= 000) at 24 months in standing position. The difference in pre-operative measurements in the six and 24-month measurements is because of the different patient numbers scanned. There were similar increased dural sac areas in the other positions. The mean foraminal areas were measured in flexion and extension and the measurements in extension were increased from 66.58 mm2 to 79.51 mm2 (p=. 001) at 6 months and from 68.10 to 69.57 mm2 (p=0.752) at 24 months on left side; and increased from 63.75 mm2 to 71.65 mm2 (p=0.036) at 6 months, from 65.54 mm2 to 68.01mm2 (p=0.440) at 24 months on right side. Thus there is a small increase in foraminal areas and statistically significant increase in dural sac areas at 24 months.

Conclusion: X-stop interspinous device remains effective in decompressing the stenosed spinal segment by increasing the anatomic dural cross sectional areas and foraminal areas of spinal canal at 24 months post operatively, thus providing symptomatic relief from lumbar canal stenosis.

Aim: To study the effect of X-stop interspinous decompression device on the lumbar spine kinematics at 6 and 24 months post operatively at the instrumented and adjacent levels in patients with symptomatic lumbar canal stenosis.

Design: Prospective Observational Study of 48 patients.

Methods: Patients due to have an X stop procedure were included and had a positional MRI scan preoperatively, 6 and 24 months post operatively in erect, flexion, extension and neutral position. Disc heights, endplate angles, segmental and lumbar spine motion was measured at stenosed instrumented and adjacent levels. Osiris 4.17 software program was used to measure the canal and foraminal dimensions. The data was analysed using paired t test on SPSS ver.15.01.

Results: Forty-eight patients (25 Male and 23 Female) underwent scans preoperatively and at 6 months. Twenty-nine patients had single level and 19 had double level procedures. Three patients had removal of X stop and 5 did not have scan at 24 months, leaving 40 patients scanned at 24 months. Of these, 38 scans were complete and were included. Mean anterior disc height reduced from 7.1 mm to 6.3 mm (p=0.004) from 48 scans at 6 months and from 7.2 mm (pre-operative) to 5.9 mm (at 24 months) – (p=0.000) from 38 scans at 24 months at the instrumented level. We hypothesise that the reduction in anterior disc heights could be a result of the interspinous distraction plus the natural progression of spinal stenosis and ageing. There was no significant change in posterior disc heights at instrumented level or adjacent levels. The mean lumbar spine motion was 22.89o, 21.3 o and 21o (p=0.183) preoperatively, 6 and 24 months respectively. The total range of movements of lumbar spine and individual segments were measured. There was no significant change in the segmental range of motion at instrumented and adjacent levels.

Conclusion: X-stop interspinous device does not significantly alter the kinematics of lumbar spine at instrumented and adjacent levels at 6 and 24 months postoperatively.

Aim: To assess the clinical effectiveness of X stop interspinous decompression device in patients with neurogenic claudication due to lumbar canal stenosis at 24 months post surgery.

Design: Prospective Observational Study of 57 patients with X stop procedure.

Methods: Fifty-seven patients with unilateral or bilateral leg pain due to lumbar canal stenosis, who had significant relief from sitting or flexing the lumbar spine, were treated with X stop.

Clinical outcome was assessed by Zurich claudication questionnaire (ZCQ), visual analogue score (VAS), Oswestery disability index (ODI) and SF36 questionnaires preoperatively and at 2 years. ZCQ has three components- symptom severity, physical function and patient satisfaction. ZCQ is considered the most precise, reliable and condition specific questionnaire for lumbar canal stenosis.

Out of 57 patients, 2 died due to unrelated causes, 3 withdrew from study and 3 had the device removed within 2 years. Forty-five, 44, 42 and 48 completed ZCQ, ODI, SF-36 and VAS respectively at 24 months.

Results: The mean age was 71(53–94) and M: F ratio 29:28. X stop device was inserted at single level in 32 (56%) and double levels in 25(44%) patients. In single level cases, 72% reported improvement in symptom severity, 65% in physical function, 68% were satisfied with the procedure, and overall 55% made a clinically significant improvement at 24 months. In double level cases, the figures were 62%, 68%, 78% and 40% respectively. The threshold for changes in symptom severity was 0.46, physical function was 0.42 and patient satisfaction 2.42. Overall clinically significant improvement requires that a patient achieves at least 2 criteria.

The mean ODI improved by 6.5 in single level and 10.8 in double level cases. The SF-36 showed improvement in physical function, role physical, bodily pain and vitality social domain.

Average hospital stay for the procedure was 1.6 days. One patient stayed for 10 days for investigation unrelated to the procedure. There were no major complications.

Conclusions: The results of our study show that the X stop interspinous decompression device remains clinically effective at the end of 2 years. X stop is a relatively less invasive procedure, especially suitable for patients with other co-morbidities, which can be performed as a day case procedure without major complications.

Purpose of the Study: To ascertain the role of Dynesys system (Zimmer Spine, Minneapolis) in the surgical management of chronic low back pain

Methods: 55 patients with persistent low back pain despite conservative measures were treated with Dynesys over a period of two and a half years. Participants either underwent Dynesys procedure alone or in combination with fusion or decompression surgery. Oswestry Disability Index (ODI), Visual Analogue Scores (VAS) and SF-36 questionnaires were completed pre-operatively and at one and two years post-operatively. Pre-operative testing using the Distress and Risk Assessment Method (DRAM) identified psychological distress prior to surgery. Patient Oriented Outcome questionnaires were circulated retrospectively following surgery to obtain data regarding patient’s perceptions and expectations of their outcome.

Results: Overall, the mean ODI reduced by 10.23% after one year and 16.15% after two years following surgery. VAS improved by 12mm one year and by 17mm two years after operation. Patients with psychological distress pre-operatively showed less improvement in their ODI and VAS at two-year follow up. The results of fusion were similar to Dynesys alone, and patients who also had decompression had best results. 72.2% patients reported an improvement following their surgery and the same percentage would have the operation again in retrospect.

Conclusion: This is the first study exploring clinical outcomes following surgery using Dynesys dynamic stabilization system in patients with disabling low back pain. Previous studies have reported good outcome in the treatment of spinal stenosis. Over 70% patients in our study reported improvement following the procedure but more evidence is needed to determine if it is a viable alternative to spinal fusion.

Aim: To assess the kinematic changes that occur within the lumbar spine 2 years following insertion of the Dynesys Spinal stabilisation implant.

Materials and Methods: Twenty patients who were treated with Dynesys surgical stabilisation for dominant lower back pain underwent positional MRI scanning before and two years following surgery.

The patients were divided into two groups, A and B. The first, Group A, in which only Dynesys was used and the second, Group B, in which Dynesys was used adjacent to one or more fused segments.

Results: The results of the pMRI measurements showed that the range of movement (ROM) of the L1/S1 angle in Group A reduced by 11.8o{pre-op=37.9o, postop=26.1o(p=0.085)} while in Group-B reduced by 12.3o {pre-op=37.8o, postop=25.5o(p=0.017)}.

The ROM of the end plate angle at the instrumented segments in Group A reduced from 5.72^o to 1.44^o{difference 4.28^o(p=0.005)} and in Group B reduced from 6.00^o to 2.17^o,{difference 3.83^o(p=0.001)}.

The ROM of the end plate angle at the level above instrumentation in Group A reduced from 8.2^o to 5.1^o {reduction 3.1^o(p=0.085)}, while in group-B increased from 7.3^o to 7.5^o, a difference of 0.2^o (p=0.877).

The mean anterior disc height in Group A reduced by 2.1mm (p< 0.001) from 9.59mm to 7.44mm. The posterior disc height also reduced from 6.56mm to 6.26mm, a difference of 0.3mm, (p=0.434). In Group B, the anterior disc height reduced by 1.98mm (pre-op=9.04mm, post-op= 7.06mm, p=0.001) and the posterior height by 0.35mm (pre-op 6.14mm to post op 5.79mm, p=0.443)

Discussion: This study shows that the Dynesys stabilisation system allows some movement at the operated segment two years following surgery. The study also confirms that the adjacent segment hypermobility often seen following spinal fusion surgery is eliminated.

Purpose of the Study: To assess the use of synthetic hydroxyapatite for postero-lateral spinal fusion using a new classification system

Methods: This is a prospective study on 30 patients who underwent bilateral postero-lateral spinal fusion between October 2002 and January 2004. The sides were randomised to synthetic phase pure Hydroxyapatite (Apapore® 70) mixed with bone marrow and autologus bone on one side and Apapore® 70 with bone marrow on the other. Plain Antero-posterior and Lateral x-rays were done in the immediate post-operative period and at 3, 6, 12 and 24 months. Two independent observers assessed the Antero-posterior films using a new classification system. Spine was considered fused when either or both sides showed good evidence of bone formation between the graft particles and graft and transverse process.

Results: In 6 patients x-rays were lost and 2 did not have two year follow-up. Twenty of the remaining 22 patients (90.9%) showed evidence of fusion as documented by both the observers. Good evidence of bone formation was noted as early as 6 months on the side where Apapore was used with bone marrow with 90.9 % achieving fusion at 2 years as against 57.1 % on the opposite side. The inter-observer agreement was good (mean 81.6%) with kappa score of 0.736.

Conclusion: The Hydroxyapatite based bone graft substitutes behave differently than autologus bone graft and poses difficulty in assessing fusion according to the radiographic classification systems described. The classification described above is useful in such situations and has shown to have good inter-observer reliability. With the increasing use of bone substitutes this classification system may be valuable in assessment of fusion and inter-study correlation.

Purpose: To evaluate the changes in lumbar spine kinematics and clinical outcomes of patients with spinal stenosis 2 years after implantation of the X Stop interspinous decompression device.

Methods: 10 patients (6 males; 4 females) underwent X Stop procedure. Age ranged from 57 years to 71 years. 15 levels were operated (5 single levels: L_2-3 - 1, L_4-5 - 4; 5 double levels: L_3-4 +L_4-5 – 4; L_4-5+L₅S₁ – 1). A 0.6 Tesla Upright MRI scanner was used to acquire images in seated (flexion, extension, and neutral) and erect postures at preoperative, 6 months, and 2 years after surgery. The total range of motion of the lumbar spine and the operated segments were measured, along with changes in disc height, areas of the exit foramens, and dural sac. Clinical outcomes were assessed by Zurich Claudication Questionnaire before and 3, 6, 12, and 24 months after surgery.

Results: Mean Zurich Claudication Scores (n=10)

At 6 months, there was a significant increase in the spinal canal and foraminal dimension. However at 2 years there was a reduction in these dimensions such that there was no significant difference from the preop-erative measurements.

Conclusion: The results of this prospective observational study indicate that X Stop offers significant short-term improvement. It is a safe, effective, and less invasive alternative for treatment of lumbar spinal stenosis. The maximum clinical benefit and mechanical efficacy seems to be realized in the early stages postoperatively with gradual reduction thereafter over 2 years. Co-existing co-morbidities such as obesity and osteoarthritis in the lower limbs may influence the clinical results.

Background: It has been demonstrated that a relationship exists between pro-inflammatory cytokine levels and psychological distress. Psychological distress commonly co-exists with back pain and may be detrimental to rehabilitation in such patients undergoing surgery. We aim to establish whether a link exists between psychological distress and increased levels of Interleukin- 6 (IL-6) and it’s soluble receptor (sIL-6r) in patients undergoing surgery for low back pain.

Methods: All individuals selected for spinal fusion or stabilisation surgery, in whom low back pain was the predominant feature, were eligible for inclusion. Participants completed both the Distress and Risk Assessment Method (DRAM) and Hospital Anxiety and Depression Score (HADS) questionnaires pre-operatively. Blood samples for serum IL-6, sIL-6r and high sensitivity C-Reactive Protein (CRP) levels were extracted at recruitment and results were compared with questionnaire findings.

Results: 63 patients were recruited of whom 90.5% had some degree of measurable psychological distress. Patients were divided into two groups based upon the degree of their distress.

Mean IL-6 levels were higher in groups of patients with more distress measured by the DRAM and HADS depression component but were lower in patients with more anxiety. IL-6 receptor levels were higher in patients with raised DRAM and HADS anxiety scores.

No significant correlation between questionnaire responses and cytokine levels was found. A correlation exists between IL-6 and CRP levels even at normal levels of CRP.

Conclusion: There does not appear to be a significant relationship between IL-6 and sIL-6r levels and psychological distress in back pain patients.

Aim: To assess the kinematic changes that occur within the lumbar spine 2 years following insertion of the Dynesys Spinal stabilisation implant.

Materials and Methods: Twenty patients who were treated with Dynesys surgical stabilisation for dominant lower back pain underwent positional MRI scanning before and two years following surgery.

The patients were divided into two groups, A and B. The first, Group A, in which only Dynesys was used and the second, Group B, in which Dynesys was used adjacent to one or more fused segments.

Results: The results of the pMRI measurements showed that the range of movement (ROM) of the L1/S1 angle in Group A reduced by 11.8o{pre-op=37.9o, postop=26.1o(p=0.085)} while in Group-B reduced by 12.3o {pre-op=37.8o, postop=25.5o(p=0.017)}.

The ROM of the end plate angle at the instrumented segments in Group A reduced from 5.72^o to 1.44^o{difference 4.28^o(p=0.005)} and in Group B reduced from 6.00^o to 2.17^o,{difference 3.83^o(p=0.001)}.

The ROM of the end plate angle at the level above instrumentation in Group A reduced from 8.2^o to 5.1^o {reduction 3.1^o(p=0.085)}, while in group-B increased from 7.3^o to 7.5^o, a difference of 0.2^o (p=0.877).

The mean anterior disc height in Group A reduced by 2.1mm (p< 0.001) from 9.59mm to 7.44mm. The posterior disc height also reduced from 6.56mm to 6.26mm, a difference of 0.3mm, (p=0.434). In Group B, the anterior disc height reduced by 1.98mm (pre-op=9.04mm, post-op= 7.06mm, p=0.001) and the posterior height by 0.35mm (pre-op 6.14mm to post op 5.79mm, p=0.443)

Discussion: This study shows that the Dynesys stabilisation system allows some movement at the operated segment two years following surgery. The study also confirms that the adjacent segment hypermobility often seen following spinal fusion surgery is eliminated.

Introduction: This prospective observational study reports on the clinical efficacy of a complete case series of patients who have had X STOP interspinous device insertion for the treatment of lumbar spinal stenosis.

Methods: 60 patients were enrolled and asked to complete the ZCQ, ODI, SF-36 and VAS questionnaire’s pre-operatively, and at 3-, 6- and 12 months post-operatively. Clinical significance with the ZCQ is accepted as improvement in 2 of the 3 domains (where the changes correspond to a mean decrease of 0.42 or 0.46 for symptom severity or physical function respectively, or there is a mean patient satisfaction score of 2.4 or less). Changes in ZCQ were measured at each time point and compared to pre-operative levels.

Results: The mean age was 70 (range 54–90), M:F 29:30. Two of the 59 patients were withdrawn due to intra-operative spinous process fracture and unrelated death. 60% underwent single level and 40% double level insertion.

The ZCQ, ODI, SF-36 and VAS were completed preoperatively and at 12 months by 54, 50, 52, 52 respectively.

Thirty-nine patients completed all questionnaires at all time points and the maximal clinical efficacy was evident 3 months post-operatively. Clinical significant improvement was maintained at the 6- and 12 month post-operative follow-ups despite a minimal loss of clinical efficacy in absolute mean values.

Overall, clinically significant response was achieved in 65%. Seventy-one per cent of double level patients and 61% of single level patients as determined by the ZCQ, had a clinically significant response. Corresponding changes were seen in VAS and ODI and SF-36.

Ten patients (18%) required caudal epidural for recurrence of symptoms and 1 patient required perifacet injections for back pain.

Conclusion: X STOP offers a safe reversible treatment for symptomatic spinal stenosis. Clinically significant improvement is present at three months and is maintained at 12 months.

Purpose: We present the early results of a pilot study of 10 patients evaluating the basic safety and performance of an in situ polymerising protein hydrogel used in discectomy to prevent recurrent nuclear herniation, reduce motion segment instability and preserve disc height.

Method: Patients with radicular symptoms due to a MRI scan proven disc herniation, failed at least 3 months of conservative therapy, and had mild to moderate disc space narrowing. A standard open discectomy was performed to create a cavity for the implant, which was injected into the void through the annulotomy. The implant polymerised within 2 minutes. All patients had standard post-operative care for open discectomy.

The patients were assessed pre-operatively and post-operatively at 6 weeks, 3, and 6 months using Visual Analogue pain scale (VAS), Oswestry Disability index (ODI), SF-36 Health Survey (SF-36) and positional MRI scan in sitting (flexion, extension and neutral), erect and supine positions. To date, seven patients have a six-month follow up.

Results: Six females and 4 males were implanted into either the L4/L5 (5 patients) or L5/S1 (5 patients) level. The mean age of the patients was 40.6 years with a range of 19–57 years. ODI decreased from a mean of 49.2 pre-operatively to a mean of 11 at 6 months, and numerical pain score from of 5.86 to 1.62. Physical Component Score improved from a mean of 28.52 pre-operatively to 48.10 at 6 months. Two patients have suffered recurrent herniation, male (L5/S1) at 10 days, and a female (L5/S1) at 8 months, both requiring surgery.

Conclusion: Early clinical results indicate that the material can be used to fill the nuclear void following discectomy. Long-term data will be collected and evaluated to determine its efficacy in reducing spinal segment instability and preserving disc height.

Introduction: The effect of the X-STOP on sagittal kinematics and spinal canal and neural foraminal area are reported when this interspinous device is used for the treatment of neurogenic claudication.

Methods: Patients underwent Positional MRI scanning pre-operatively and 6 months post-operatively in the erect, flexed seated and extended and neutral positions. Anterior and posterior disc heights were measured on the erect images, endplate angle and the L1S1 angle on flexion and extension images at the operated and adjacent levels. Spinal canal and neural foraminal area were measured on all images. Measurements were made using the Osiris 4.17 program and statistical analysis using the Wilcoxon sign rank test.

Results: Fifty-two patients were enrolled. M:F 26:26. Single level: Double level insertion 29:20. Three patients withdrawn, one died of unrelated causes, one intra-operative spinous process fracture, one lost to follow-up.

Single Level: Spinal canal and neural foramina areas were increased in all positions with canal area significantly increased on standing (p=0.024) and sitting neutral (p=0.036). There was no significant effect on endplate angle, segmental range of movement, L1S1 angle or disc height.

Double Level: Spinal canal area was significantly increased in the cranial segment on standing (p=0.002) and extension (p=0.016) and the caudal segment in extension (p=0.016). Foraminal area was significantly increased at the right cranial (p=0.019) and caudal (p= 0.045) segments in flexion and left cranial (p=0.017) and caudal segments (p=0.004) in extension. A significant change was observed at the endplate angles in flexion (p=0.028) and extension (p=0.026) at the upper level. The L1S1 angle was significantly reduced in extension (p=0.017). The caudal anterior disc height was reduced (p=0.023). There was no significant effect on segmental range of movement or sagittal kinematics at adjacent levels.

Conclusion: X-STOP insertion has minimal effect on the sagittal kinematics of the lumbar spine but does increase canal and neural foraminal area.

Introduction: This abstract describes the development of an effective procedure for removing as much nucleus as possible from an intervertebral disc with minimal disruption to the annulus. The procedure was developed on cadaveric sheep discs which are well established as a model for human discs in studies of this kind. The purpose of the study was to develop a method for removing the nucleus as part of a laboratory study of nucleus replacement; however, it is also intended to guide the development of procedures for the removal of residual nucleus when indicated in surgical procedures that involve replacing the nucleus with synthetic materials.

Methods: All procedures were performed via a 3 mm trocar. Four procedures were compared: (I) unilateral approach using rongeurs alone, (II) bilateral approach using rongeurs alone, (III) unilateral approach using rongeurs followed by chymopapain and (IV) bilateral approach using rongeurs followed by chymopapain. Chymopapain was administered as a solution (30 units in 0.1 cm³ de-ionised water) to a disc at 37^oC. For each procedure (I–IV) 14 discs were used.

Results: The percentages of nucleus removed were: (I) 34 ± 2%, (II) 41 ± 2%, (III) 52 ± 3% and (IV) 75 ± 8%; ANOVA showed a significant differences between the four sets of results (P < 0.05).

Conclusions: Significantly more nucleus is removed using a bilateral than a unilateral approach; significantly more nucleus is removed if chymopapain is used in addition to rongeurs.

Purposes Of The Study-Background Data: Dynesys is claimed that allows motion in the operative levels. This study measures the changes in the lumbar spine in different postures, pre- and after insertion of the device.

Thirty patients with were treated with Dynesys system. All had discography and positional MRI preoperatively and nine months post-operatively.

The patients were divided in to two groups. The first in which only Dynesys was used and the second in which Dynesys was used with fusion.

Results: The operated levels were 63. The results of the pMRI measurements showed that the range of movement(ROM) of the L1/S1 angle in group-A reduced by 11.89^o{pre-op=39.26^o,postop=27.37^o(p=0.008)} while in group-B reduced by 13.73^o {preop=36.18^o,po stop=22.45^o(p=0.002)}.

The ROM of the end plate angle at the instrumented segments in group-A reduced from 5.24^o to 2.18^o{difference 3.06^o(p< 0.005)} and in group-B reduced from 6.69^o to 2.46^o,{difference 4.23^o(p=0.008)}. The ROM of the end plate angle at adjacent level in group-A changed from 8.26^o to 7.0^o {reduction 1.26^o(p=0.388)},while in group-B increased from 6.91^o to 8.64^o, {difference 1.73^o(p=0.149)}

The mean anterior disc height in-group A reduced by 1.43mm (p< 0.005) from 9.75mm to 8.32mm, and the posterior one was increased from 6.27mm to 6.77mm {difference of 0.5mm,(p=0.008)}. In group-B the anterior disc height reduced by 1.11mm (pre-op=10.44mm,post-op= 9.33mm,p=0.049) and the posterior one by 0.16mm (pre-op 6.98mm to post-op 6.82mm,p=0.714).

Conclusion: This study shows that in the Dynesys stabilizing system allows small range of movement at the instrumented levels, with no significant increased mobility in the adjacent levels. Also the device acted to compress the anterior annulus.

Purpose: To measure the effect of the X-Stop interspinous distraction device on spinal canal, exit foramina, and disc height dimensions at the operated level; and adjacent segment endplate angle, and lumbar spine movement in patients with symptomatic lumbar spinal stenosis using upright MRI.

Methods /Results: 14 patients (9 M;5 F) were scanned before and six months after operation. Age ranged from 57 to 88 years. All had symptomatic lumbar spinal stenosis- single level- 9 (L2/3-1; L3/4-1; L4/5-7); double level 5 (L3/4, L4/5).

Images were taken in sitting flexed, extended, neutral, and standing. The total range of motion of the lumbar spine and of the individual segments were measured, along with changes in disc height, areas of the exit foramina, and dural sac.

The mean area of the dural sac at the operated levels increased from 62.46mm2 to 77.69mm2 (p=0.004) in the standing posture and from 70.85mm2 to 94.62mm2 (p=0.019) in extension postoperatively. The area of the exit foramina in extension increased from 83.57mm2 to 107.88mm2 (p=0.002) on the left side and from 83.77mm2 to 108.69mm2 (p=0.012) on the right. The overall changes in the range of movement of the individual segments or of the lumbar spine were statistically insignificant.

Conclusions: This is the first study carried out using an upright MRI scanner in patients with lumbar spinal stenosis. The X-Stop device increases the cross-sectional area of the spinal canal and exit foramina by distracting the spinous processes of the operated level without significantly affecting overall posture of the lumbar spine.

Purpose Of The Study: This study measures the changes in the lumbar spine in different postures, pre- and after insertion of the device.

Material-Method-Results: All the 25 patients, with chronic back pain, had discography preoperatively a positional MRI scans pre-op and nine months postoperatively in different postures.

The patients were divided into two groups. The Group-A with 14 patients in which only Dynesys was used and Group-B with 11 patients in which Dynesys was combined with fused levels.

The operated levels were 51, 13 of which were fused. The results showed that the mean range of movement of the lumbosacral angle reduced by 10.28° (Preop=39.21°, Postop=28.93°) (p=0.016) in group-A. In group-B it reduced by 13.73° (Preop=36.18°, Postop=22.45°) (p=0.02).

The range of movement of the end plate angle at the instrumented segments in group-A reduced by 2.96° (Preop=5.56°, Postop=2.60°) (p=0.016) while in group-Bit reduced by 4.23° (Preop=6.69°, Postop=2.46°)(p=0.008).

The mean range of movement of the end plate angle at adjacent level in group-A reduced by 1.58° (Preop=8.7°, Postop=7.21°)(p=0.427) while in group-B it increased by 1.73° (Preop=6.91°, Postop=8.64°) (p=0.149)

The mean anterior disc height in group-A reduced by 1.18mm (Preop=10.05mm, Postop=8.87mm) (p< 0.005), and the posterior one was increased by 0.6mm (Preop=6.51mm, Postop=8.87mm) (p=0.013). In group-B, the anterior disc height was reduced by 1.11mm (Preop= 10.44mm, Postop=9.33mm) (p=0.049) and the posterior one by 0.16mm (Preop=6.98mm Postop=6.82mm) (p=0.714)

Conclusion: Dynesys stabilizing system allows movement at the instrumented levels, with no significant increased mobility in the adjacent levels. Also the device acted to compress the more the anterior annulus than to distract the posterior.

Introduction Symptoms of neurogenic intermittent claudication in spinal stenosis are explained by the narrowing of the spinal canal in the extended (upright) position and widening in the sitting (flexed) position. The XStop inter-spinous process distraction device is a new product that is designed to hold the affected segments in a flexed posture. This prospective study looks at the changes in the lumbar spine in a variety of postures from pre- to post insertion.

Methods Using a positional magnetic resonance imaging (pMRI) scanner, patients were scanned before and six months after the insertion of the device. Images were taken in sitting flexed and extended, and standing positions. The change in the total range of movement of the lumbar spine and in the individual operated segments was measured along with changes in the surface areas of the exit foramen, the dural sac, and the disc height.

Results 12 patients with 17 levels distracted have been scanned and measured. The cross sectional area of the dural sac at the level of the stenosis has increased from a mean of 77.8 mm² to 93.4 mm² in the standing position (p=0.006) and from 84.56mm² to 107.35mm² on extension (p=0.008). There were no statistically significant changes in the range of movement of the whole lumbar spine, or at levels adjacent to the device.

Discussion This study demonstrates that the X Stop device increases the cross sectional surface area of the spinal canal at the stenosed level, without causing extensive changes in the posture of the lumbar spine.

Introduction This abstract describes the development of an effective procedure for removing as much nucleus as possible from an intervertebral disc with minimal disruption to the annulus. The procedure was developed on cadaveric sheep discs which are well established as a model for human discs in studies of this kind. The purpose of the study was to develop a method for removing the nucleus as part of a laboratory study of nucleus replacement; however, it is also intended to guide the development of procedures for the removal of residual nucleus when indicated in surgical procedures that involve replacing the nucleus with synthetic materials.

Methods All procedures were performed via a 3 mm trocar. Four procedures were compared: (I) unilateral approach using rongeurs alone, (II) unilateral approach using rongeurs followed by chymopapain, (III) bilateral approach using rongeurs alone and (IV) bilateral approach using rongeurs followed by chymopapain. Chymopapain was administered as a solution (30 units in 0.1 cm³ de-ionised water) to a disc at 37°C. For each procedure (I–IV) 14 discs were used.

Results The percentages of nucleus removed were: (I) 34 ± 2%, (II) 41 ± 2%, (III) 52 ± 3% and (IV) 75 ± 8%; ANOVA showed a significant differences between the four sets of results (P < 0.05).

Conclusions Significantly more nucleus is removed using a bilateral than a unilateral approach; significantly more nucleus is removed if chymopapain is used in addition to rongeurs. A brush is useful in removing strands of nucleus loosened by chymopapain. For the purpose of these experiments a bottle brush with nylon bristles was trimmed to an overall diameter of about 10 mm, so that it could be inserted into the nuclear cavity via the trocar. Design of a surgical instrument for this purpose would be guided by a preliminary risk analysis.

Introduction The Dynesys device uses transpedicular screws linked by a cord and spacers. It is claimed that the advantage is that it allows some motion, in all directions, in the operative levels. In vitro laboratory biomechanical studies show that the movement permitted is similar to rigid fusions.

This study measures the changes in the lumbar spine in different postures, pre- and after insertion of the device.

Material-method In our study 20 patients with dominant low back pain, with or without leg pain, were treated with Dynesys system. Stress discography was made to evaluate the symptomatic level

All had a positional MRI preoperatively and nine months post-operatively in flexion-extension-lateral bending.

The patients were divided in to two groups:

Group(A) with 8 patients in which Dynesys was used with fusion (disc-height< 40 %)

Group(B) with 12 patients was the Dynesys-only group (disc-height=40–90%).

Results The operated levels were 42, 10 of those were fused levels. The results showed that there was a statistically significant difference in flexion-extension range of movement of the whole lumbar spine (mean= −13.45)(p< 0.005), but it wasn’t significant in the level above (mean=0.056)(p=0.972) and at a single instrumented segment was (mean=−4.06°)(p< 0.05)

The changes in the anterior disc height was (mean= −1.18)(p< 0.05) and to the posterior (mean=0.37)(p=0.134). In bending were (mean=−0.87°)(p=0.18) for left and (mean=−0.24°)(p=0.75) for the right

Discussion This study shows that in the Dynesys stabilizing system allows small range of movement at the instrumented levels, with no significant increased mobility in the adjacent levels. Also the device acted to compress the anterior annulus

Study Design: A prospective randomised controlled trial with blind radiological assessment.

Objective: To assess the radiological outcome of instrumented posterolateral lumbar fusion in a prospective randomised study comparing the use of allograft (fresh frozen human femoral head) to autologous bone (from the posterior iliac crest) using a validated method.

Methods: Sixty-nine patients having instrumented postero-lateral fusion using the Steffee plate were randomised to one of two groups, to receive either allograft bone or autologous bone. The same surgeon using the same surgical technique performed or supervised all cases. The radiological results of the two groups were assessed as well as the quality of fusion.

Outcome measures: The radiographs were assessed for fusion or non-fusion by three independent observers using the same criteria, and a second time by one of the observers. The Kappa scores for the inter-observer and intra-observer agreement were calculated. Some of these patients had fusion status verified by the gold standard of surgical exploration and the sensitivity and specificity calculated. The clinical outcome is the subject of a different paper.

Results: Both the inter-observer and intra-observer kappa scores (k) were 100%. The sensitivity of the method was 87.9% and the specificity was 100%. Thirty-seven patients received allograft and 32 patients received autograft. There was no significant difference in the fusion rate, or the quality and quantity of the graft between the groups.

Conclusions: There is no difference in the fusion rates comparing the use of autograft and allograft for postero-lateral instrumented lumbar fusion.

Introduction Symptoms of neurogenic intermittent claudication in spinal stenosis are explained by the narrowing of the spinal canal in the extended (upright) position and widening in the sitting (flexed) position. The X-Stop® inter-spinous process distraction device (St. francis Medical Technologies) is a new product designed to hold the affected segments in a flexed posture. This prospective study looks at the changes in the lumbar spine in a variety of postures from pre- to post-insertion.

Method Using positional MRI (pMRI), patients were scanned before and six months after operation. Images were taken in sitting flexed, extended, neutral, and standing positions. The total range of motion of the lumbar spine and of the individual operated segments were measured, along with changes in disc height, areas of the exit foramina, and dural sac.

21 patients (11 males; 10 females) were included in the study. Age ranged from 57 – 88 years. All had symptomatic lumbar spinal stenosis- single level- 13 (L2/3-1; L3/4-3; L4/5-9); double level 8(L3/4, L4/5 – 7; L4/5, L5/ S1 – 1).

Results The mean area of the dural sac at the operated levels increased from 89.25mm2 to 108.96mm2 (p< 0.001) in the standing posture and from 103.96mm2 to 124.94mm2 (p< 0.001) in extension postoperatively. The area of the exit foramina in extension increased from 79.15mm2 to 100.41mm2 (p< 0.001) on the left side and from 80.86mm2 to 98.74mm2 (p< 0.001) on the right side. The overall changes in the range of movement of the individual segments or of the lumbar spine were statistically insignificant.

Discussion Previous, radiologic (Willen J, et al; Spine 1997) and cadaveric studies have demonstrated reduction in area of the dural sac and exit foramina as the lumbar spine moves from flexion into extension. Our study is the first to quantify these changes in symptomatic patients with lumbar spinal stenosis using postional MRI. This study supports previous studies using positional MRI scanner in patients with lumbar spinal stenosis and also demonstrates that the X-Stop device increases the cross-sectional area of the spinal canal and exit foramina by distracting the spinous processes of the operated level without significantly affecting overall posture of the lumbar spine.

Introduction The Dynesys® stabilisation system (Zimmer Spine) uses transpedicular screws linked by a cord and spacers; the advantage claimed is that it allows some motion, in all directions, in the operated levels. In vitro laboratory biomechanical studies show that the movement permitted is similar to rigid fixation systems.

This study measures the changes in the lumbar spine in different postures, pre- and after insertion of the device. Methods In our study 25 patients with dominant low back pain, with or without leg pain, were treated with Dynesys system, 14 females and 11 males with mean age 43.5 yrs. Discography was done to evaluate the symptomatic painful level. All patients had a positional magnetic resonance imaging (pMRI) scans preoperatively and nine months post-operatively in standing; sitting flexion and extension, and left and right bending postures. The patients were initially divided into two groups. The first (Group A) with 14 patients in which only Dynesys was used (disc height 40–90%) and the second (group B) with 11 patients in which Dynesys was used with fusion (disc height < 40 %).

Results The operated levels were 51, 13 of which were fused. The results of the pMRI measurements showed that the mean range of movement of the lumbosacral angle reduced by 10.3° from pre-op of 39.2° to postop. of 28.9° (p= 0.016) in group A while in group B it reduced by 13.7° from 36.2° preop. to 22.5° postoperatively (p= 0.02).

The range of movement of the end plate angle at the instrumented segments in group A reduced from 5.6° preoperatively to 2.6° with a difference of 3.0° (p=0.016) while in group B it reduced from 6.7° to 2.5° postoperatively with a difference of 4.2°(p=0.008). The range of movement of the end plate angle at adjacent level in group A changed from 8.8° preop. to 7.2° with a reduction of 1.6° (p=0.427) while in group B it increased from 6.9° to 8.6°, difference of 1.7° (p=0.149)

The mean anterior disc height in group A reduced by 1.2mm (p< 0.005) from 10.1mm to 8.9mm postoperatively, and the posterior one was increased from 6.5mm to 8.9mm with a difference of 0.6mm (p= 0.013). In group B the anterior disc height was reduced by 1.1mm (pre-op 10.4mm to post-op 9.3mm; p=0.049) and the posterior one by 0.16mm (pre-op 6.98mm to post-op 6.82mm; p=0.714)

Discussion This study shows that in the Dynesys stabilising system allows a small range of movement at the instrumented levels, with no significant increased mobility in the adjacent levels. Also the device acted to compress the anterior annulus more than to distract the posterior annulus.

Introduction Conventional MRI scanners require the patient to lie in a supine position within the bore of the magnet; positional MRI (pMRI) scanners allow patients to be scanned in any position. This is of particular value when patients have postural dependent symptoms.

Here we discuss the evaluation of two spinal devices: Dynesys, a spinal stabilisation system for back pain, and X STOP, an interspinous process distraction device for spinal stenosis.

Materials, Methods & Results For each device, patients underwent pre and post-operative scans in standing, lying and seated in neutral, flexed and extended positions and the ranges of movement at the operated levels and across the whole lumbar were measured.

For Dynesys, 30 patients with lower back pain were recruited. The first 20 patients have completed their 9 month scan, and the results show that the device reduces the range of movement at the operated segments, with a small increase in movement at adjacent segments and an overall reduction in the range of movement of the lumbar spine.

For X STOP, the first 10 of 45 have reached their second scan at 6 months post surgery. The scans demonstrate a net increase in the cross-section of the spinal canal of 21% when flexed to 35% whilst standing, and an increase in the surface area of the exit foramen of 23% flexed and 51% standing at operated levels.

Conclusion These studies demonstrate the value of pMRI for the evaluation of lumbar spine prosthesis. pMRI allows for the assessment of the devices in their functional (i.e. upright) position.

To assess the radiological outcome of instrumented posterolateral lumbar fusion in a prospective randomised study comparing the use of allograft (fresh frozen human femoral head) to autologous bone (from the posterior iliac crest), using a validated method.

One hundred and twenty four radiographs of patients who had undergone instrumented posterolateral spinal fusion were assessed for fusion or non-fusion by three independent observers using the same criteria, and a second time by one of the observers. The Kappa scores for the inter-observer and intra-observer agreement were calculated. Thirty-three of these patients had fusion status verified by the gold randomised to one of two groups, to receive either allograft bone or autologous bone. The same surgeon using the same surgical technique performed or supervised all cases. The radiological results of the two groups were assessed as well as the quality of fusion.

Both the inter-observer and intra-observer kappa scores (k) were 100%. The sensitivity of the method was 87.9% and the specificity was 100%. Thirty-seven patients received allograft and 32 patients received autograft. There was no significant difference in the fusion rate, or the quality and quantity of the graft between the groups.

There is no difference in the fusion rates comparing the use of autograft and allograft for posterolateral instrumented lumbar fusion.

This prospective study was carried out to correlate findings of magnetic resonance imaging (MRI) and discography. Fifty-five consecutive patients with degenerative disc disease not responding to non-operative treatment were included in the study. There were 19 men and 36 women and the mean age was 45 years. Discography was carried out on 131 disc levels. The discograms were classified using modified Adams’s classification and pain recorded into three grades. MRI scans were graded using a new classification system based on parasagittal and axial images by two independent observers blinded to discography findings. There was good intraobserver (kappa 0. 74) and interobserver (kappa 0. 70) agreement for the classification system. There was a significant correlation in the morphology of discs as determined by discograms and MRI classification (p< 0. 001).

Each disc was graded on MRI scan as painful or painless on basis of defined criteria. Concordant discography pain was considered as the gold standard. The sensitivity and specificity of MRI in predicting symptomatic disc using defined criteria was 94% and 77%. The sensitivities and specificity of high intensity zones was 27% and 87% and for end plate changes was 32% and 98% respectively. In 14 patients (25%) the findings of MRI and discography did not correlate.

In conclusion though MRI is an excellent investigation for assessing disc morphology it should be interpreted along with discography findings before planning fusion surgery. The proposed MRI classification is a useful aid in predicting painful degenerative disc. The utility of high intensity zones and end plate changes is limited due to low sensitivity.

The role of MRI or CT in the management of patients with LBP, for whom there is no clear clinical indication for the use of sophisticated imaging, is uncertain. The aim of The Scottish Back Trial was to determine whether early use of MRI or CT influences clinical management and outcome of patients with LBP and whether it is cost-effective.

Elective patients were new referrals to orthopaedic or neurosurgeons with symptomatic lumbar spine disorders (without ‘red flags’). After obtaining informed consent, patients were randomised to ‘early imaging’ (imaging as soon as practicable) or ‘delayed, selective imaging’ (imaging only if an imperative clinical indication developed). Principal outcomes measures were the SF-36, questionnaire, the Aberdeen LBP Scale and the EQ-5D. Patients completed questionnaires at trial entry and after 8 and 24 months.

From 15 hospitals, 2657 patients were assessed and 783 were recruited and randomised. Eight months and twenty-four months after trial entry, comparison of data abstracted from case notes indicated that, apart from the use of imaging, both groups had received similar clinical management. At follow-up, an improvement in health status, as measured by the SF-36 and Aberdeen LBP Scale, was reported by both groups. At 24 months, there was a statistically significant but small difference in favour of the ‘early imaging’ group (p=0. 002) as measured by the Aberdeen LBP Scale but no difference in the SF-36 except a marginal improvement in the bodily pain subscale.

The use of MRI or CT imaging for this group of LBP patients did not significantly affect their management. The clinical significance of the marginal improvement in health status in the ‘early imaging’ group is uncertain. The results of the cost-effectiveness analysis may clarify whether a policy of ‘early imaging’ would be a cost effective use of resources.

We carried out a randomised, prospective, multicentre clinical trial of the treatment of Colles’ fractures. A total of 339 patients was placed into two groups, those with minimally displaced fractures not requiring manipulation (151 patients) and those with displaced fractures which needed manipulation (188 patients). Treatment was by either a conventional Colles’ plaster cast (a control group) or with a prefabricated functional brace (the Aberdeen Colles’ fracture brace).

Similar results were obtained in both groups with regard to the reduction and to pain scores but the brace provided better grip strength in the early stages of treatment. This was statistically significant after five weeks for both manipulated and non-manipulated fractures. At the tenth day the results were statistically significant only in manipulated fractures. There was no significant difference in the functional outcome between the two treatment groups. However, younger patients and those with less initial displacement had better functional results.

We have assessed the current range of synthetic splinting bandages, using physical and mechanical tests and the subjective opinions of patients, volunteers and orthopaedic staff. Modern bandages have some better properties than standard plaster bandage but do not conform as well, are more expensive, and potentially more hazardous.

A series of 29 patients with fractures of the tibial plateau were treated by means of a cast-brace. There were seven wedge fractures of the lateral tibial condyle, two dicondylar fractures and 20 compression fractures involving the lateral tibial plateau. The seven patients with wedge fractures were treated by skin or skeletal traction, followed as soon as possible by flexion exercises for the knee. Cast-braces were applied to all fractures as soon as possible after injury, and the patients allowed to bear weight freely. Early restoration of function of the injured limb was thereby achieved. The results of our study over a period of two and a half years indicate that cast-bracing is a very satisfactory method of treating fractures of the tibial plateau. All the fractures united, the movements and control of the knee were excellent, and valgus or varus deformity was unchanged before application and after removal of the brace.

The off-loading characteristics of the cast-braces of 30 patients with fractures of the shaft of the femur have been investigated, during axial loading, using strain-gauge transducers. These were applied at the level of the fracture, where the cast was circumferentially split, and to the hinges of the brace at the knee. They measured the load transferred between the two portions of the thigh cast, and between the thigh cast as a whole and the below-knee cast; by subtraction from the total load on the limb, the skeletal force at the fracture level and at the knee could be calculated. In all patients there was an increase in the fracture load as union progressed which was thought to be due to physiological feedback mechanism from the fracture site. The load carried by the two portions of the thigh cast and by the thigh cast as a whole was proportionately high at first and stabilised at an average of 35 per cent of body weight.

Ninety-eight fractures of the shaft of the femur were seen in one unit over the two years 1974 and 1975, and the results have been assessed in sixty-nine. Of these, thirty-eight were treated by skeletal traction in a Thomas's splint followed by skin traction, and thirty-one by skeletal traction followed by a cast-brace. The technique of application is described in some detail. The average time for application of the cast-brace was six weeks after the injury, the time in hospital eight weeks and the time till removal fifteen weeks. The patients selected for a cast-brace were in hospital for just over half the time of the others and their fractures on average united more quickly, though with some trouble from angulation of fractures of the uppermost third of the shaft. It is concluded that when used with all the judgment and skill it demands, the cast-brace method is a great advance in conservative treatment.