To determine extent of correction in spinal osteotomy for fixed sagittal plane deformity

Radiographic retrospective cohort analysis using standardised standing whole spine radiographs. Level III evidence

24 patients (14 females/10 males, av. 53.6 yrs) with sagittal plane deformity due to either ankylosing spondylitis (4), idiopathic (12), congenital (1), tumour (2), infectious (1), or posttraumatic (4) aetiologies. Max. 4 yrs follow up

Sagittal balance, lumbar lordosis correction, osteotomy angle, pelvic indices

Chevron (3), pedicle subtraction (17), and vertebral column resection (4) osteotomies were performed with the majority at L3 (9) and L2 (8). The C7-S1 sagittal vertical axis demonstrated a preoperative decompensation averaging 12.0 cm (range -7 to 37) with 55% of patients achieving normal sagittal balance postoperatively. Lumbar lordosis increased from 28.9° (range -28 to 63) to 48.9° (range 12 to 69) (22.3° av. correction). L3 osteotomy angle was largest, average 31° (range, 16 to 47). There were 11 complications comprising; major (1) and minor (1) neurological, junctional kyphosis (3), metalwork problems (2), dural tear (2) and infection (2). Four patients required additional surgery at latest follow-up. Technical outcome was good 11(50%), fair 8(36%), poor 3(14%).

Spinal osteotomy is a very effective technique to correct fixed sagittal imbalance and provide biomechanical stability. The high complication rate mandates a careful assessment of the risk/benefit ratio before undertaking what is a major reconstructive procedure. Most patients are satisfied, particularly when sagittal balance is achieved.

To compare the effect of intraoperative red cell salvage on blood transfusion and cost in patients undergoing idiopathic scoliosis surgery.

Retrospective

37 patients (36 females, 1 male) underwent scoliosis surgery from February 2007 to October 2008. Intraoperative red cell salvage (Group 1) was used. They were compared with 28 patients (23 females, 5 males) operated from January 2005 to December 2006 without the use of cell salvage (Group 2). 36 patients in group 1 had posterior surgery and 1 had anterior surgery. In Group 2, 20 patients had posterior surgery, 7 anterior and 1 patient had anterior and posterior surgery. Both groups were comparable for age, number of levels fused, preoperative haemoglobin and haematocrit values.

Amount of perioperative blood transfusion, costs

14 patients (50%) in group 2 had blood transfusion whereas only 6 (16%) were transfused blood in group 1. Average blood loss in group 1 was 1076 mls (range 315-3000) and 1626mls (419-4275) in group 2. An average of 2 units of packed red blood cells per patient was processed by the cell salvage system. Postoperative haemoglobin, haematocrit and hospital stay were comparable in both groups. Cost analysis shows the use of cell salvage is cost beneficial by £116.60 per case.

The use of red blood cell salvage reduces the amount of blood transfusion and is cost beneficial.

A literature review of bone graft substitutes for spinal fusion was undertaken from peer reviewed journals to form a basis for guidelines on their clinical use.

A PubMed search of peer reviewed journals between Jan 1960 and Dec 2009 for clinical trials of bone graft substitutes in spinal fusion was performed. Emphasis was placed on RCTs. Small and duplicated RCTs were excluded. If no RCTs were available the next best clinical evidence was assessed. Data were extracted for fusion rates and complications.

Of 929 potential spinal fusion studies, 7 RCTs met the inclusion criteria for BMP-2, 3 for BMP-7, 2 for Tricalcium Phosphate and 1 for Tricalcium Phosphate/Hydroxyapatite (TCP/HA). No clinical RCTs were found for Demineralised Bone Matrix (DBM), Calcium Sulphate or Calcium Silicate. There is strong evidence that BMP-2 with TCP/HA achieves similar or higher spinal fusion rates than autograft alone. BMP-7 achieved similar results to autograft. 3 RCTs support the use of TCP or TCP/HA and autograft as a graft extender with similar results to autograft alone. The best clinical evidence to support the use of DBMs are case control studies. The osteoinductive potential of DBM appears to be very low however. There are no clinical studies to support the use of Calcium Silicate.

The current literature supports the use of BMP-2 with HA/TCP as a graft substitute. TCP or HA/TCP with Autograft is supported as a graft extender. There is not enough clinical evidence to support other bone graft substitutes.

This study did not require ethics approval and no financial support was received.

Plain radiography has traditionally been used to investigate and monitor patients with adolescent idiopathic scoliosis. The X-ray allows a calculation of the Cobb angle which measures the degree of lateral curvature in the coronal plane. ISIS2 is a surface topography system which has evolved from ISIS, but with much higher precision and speed. It measures the three dimensional shape of the back using structured light and digital photography. This system has the benefit of not requiring any radiation. Lateral asymmetry is the ISIS clinical parameter estimating the curve of the spine in the coronal plane. The aim of this study was to compare this parameter to the Cobb angle measured on plain X-ray.

Twelve patients with idiopathic adolescent scoliosis underwent both a standing AP spine X-ray and an ISIS2 scan on multiple occasions. Both scan and X-ray were done within one month of each other. No patient underwent surgery during the study period. The Cobb angle and the degree of lateral asymmetry were calculated.

Twelve patients mean age 12.5 years (range 10-16) were investigated using both ISIS2 and X-ray. They had a mean 2.3 (1-5) combined investigations allowing for 30 comparisons. The correlation between the two measurements was r =0.63 (p=0.0002). The Cobb angle measured on ISIS2 was less than that measured by radiograph in 27 out of 30 comparisons. The mean difference between the measurements was mean 6.4° with a standard deviation of 8.2° and 95% confidence interval of 3.3° to 9.4°.

In adolescent idiopathic scoliosis, curve severity and rib hump severity are related but measure different aspects of spinal deformity. As expected, these relate closely but not precisely. ISIS2 offers the promise of monitoring scoliosis precisely, without adverse effects from radiation. The small numbers in this series focus on the group of patients with mild to moderate curves at risk of progression. In this group, ISIS2 was able to identify curve stability or progression, without exposing the subjects to radiation.

To establish the incidence of litigation in Cauda Equina Syndrome (CES) and the causes of litigation.

Review of 10 years of abbreviated records of the National Health Service litigation authority (NHSLA) (1997-2007) and eight years of medical negligence cases (MNC) reported on by the two senior authors (2000-2008).

Patients who experienced CES and litigated. There were 117 patients in the NHSLA records and 23 patients in the MNC group.

Review of timing of onset, delay in diagnosis, responsible specialist, place, and resulting symptoms

NHSLA cases. 62/117 cases were closed. The responsible specialists were as follows

The commonest failure was delay in diagnosis, and the commonest complications were “neurological”, bladder and bowel.

MNC cases. F:M;17/6. L4/5 13 cases, L5/S1 9 cases. The responsible specialist was orthopaedic (7), other (7) and in 8 cases the opinion was that there was no case to answer. Delay to treatment averaged 6.14 days. 18/23 patients described bowel and bladder symptoms, the information was not available in the remainder.

Litigation is major problem in CES. In most cases orthopaedic surgeons are litigated against, and bowel and bladder symptoms remain the most disturbing cause of litigation. These surgeons are mostly not spinal specialists. In most successful cases of litigation there is considerable delay in diagnosis and management. Where there is incomplete Cauda Equina Syndrome urgent or emergency investigation and treatment is mandatory.

Aim

We report our ten year experience of primary haematogenous non-tuberculous spinal infection.

Background: Clonidine is an 2 adrenoreceptor and imidazoline receptor agonist which has analgesic, sedative and MAC sparing effects. It has been used orally, intravenously (including as an additive to morphine in PCA devices) and epidurally in combination with local anaesthetics and alone. We hypothesised that epidural administration of clonidine without local anaesthesia might provide adequate postoperative analgesia following spinal surgery without centroneuraxial block, and that if the drug’s effect site is spinal then this might be achieved with smaller doses and with fewer side effects than if given systemically.

Method: This randomised controlled trial evaluated the effect of epidural clonidine versus saline on analgesia requirement and pain scores following spinal decompressive surgery. 66 patients were recruited and received a standardized general anaesthetic. At the end of surgery group C received a bolus of 1.5 mcg/kg of epidural clonidine followed by an infusion of 25 mcg/h for 36 to 48 hours. Patients in group P received a similar bolus and infusion of saline. Verbal pain scores, morphine consumption by patient-controlled device (PCA), sedation score, haemodynamic variables and the incidence of PONV were recorded for up to 48 hours.

Results: Pain scores in both groups were low, but significantly lower for the first 6 hours in the clonidine group. Cumulative morphine consumption, used as a proxy for pain perception, was significantly lower in the morphine group throughout the whole period; mean (SEM) at 48 hours 62 (7) mg vs 35 (7) mg.

Conclusion: Epidural clonidine has a useful effect in post operative pain relief following spinal surgery with few side effects.

Aim: To report our ten year experience of primary haematogenous spinal infection.

Method: Retrospective case note review of 42 patients presented to our unit with primary spinal infection between 1995–2005 was carried out. Demographic data, timing and modes of presentation, investigations, and methods of treatment were analysed. Information with regard to Mobility, Domestic circumstances, Oswestry disability index(ODI), Hospital Anxiety and depression score(HAD), Visual Analogue Score (VAS) for pain and coping were obtained. The cost benefit of Home Intravenous Antibiotics Service (HIAS) was also investigated.

Results: Mean age was 59.9 years (1–85) with almost equal gender distribution (M 20: F 22). Axial pain was universal. Pyrexia was seen in 62%. Time from presentation to diagnosis averaged 19days (range 0–172). Sensitivity for MRI and plain x-ray was 100% and 46% respectively. Treatment ranged from intravenous antibiotics alone to combined anterior and posterior surgery depending on the presence or absence of significant collection, neurological deficit and structural threat. Mean duration of intravenous antibiotics was 54 days (range 13–240). At mean follow up of 5.4 years (0.6–10.5) there was no mortality directly related to the infection. Recurrence rate was 14%. Significant past medical history(P=0.001), constitutional symptoms(p=0.001) and pyrexia at presentation(0.001) were positively associated with recurrence.

Mobility score dropped in 34% patients whilst domestic circumstances’ score dropped only in 34%. ODI averaged 18% (range 0–53%). Mean HAD for anxiety and depression was normal for 86% and 93% of patients respectively. VAS for pain averaged 1.3 (range 0–9) and that for distress was 1.8 (range 0–9).

Overall it was calculated that HIAS had saved a total of 940 in-patient days.

Conclusion: Primary spinal infection is a treatable condition. Disease and patient characteristics dictate the management strategy. Although most patients can regain their pre infection mobility and go back to their pre morbid domestic circumstances with little or no pain and psychological sequel, a proportion of patients end up with moderate to severe disability, pain and psychological problems despite successful treatment of the primary infection. Finally, HIAS was cost effective.

Aim: In this study we present our ten year experience of primary spinal infection.

Method: Retrospective case note review of 42 patients who presented to our institution with primary spinal infection between 1995–2005 was carried out. Demographic data and information with regard to timing and modes of presentation, results of radiological and laboratory investigations, and methods of treatment were collected. The financial impact of Home Intravenous Antibiotics Service (HIAS) was also investigated.

Results: Axial pain was the most consistent symptom seen in 100% of the patients. Only 62% had pyrexia at presentation. Major neurological deficit was seen in 10.2%.

Mean duration of symptoms was 25 days (range 1–202). Mean time from presentation to diagnosis was 19 days (range 0–172). Staphylococcus Aureus was the most common organism. Mean duration of Intravenous antibiotics was 60 days (range 13–240) followed by oral antibiotics for mean duration of 65 days (range 0–161). CRP was more reliable in monitoring the disease over time. At mean follow up of 5.4 years (0.6–10.5) there has been no mortality directly related to the infection. With our management there has been 14% recurrence rate. All re- presenting within the first year after initial presentation (Mean 5.5 Months, range 1–11).

HIAS saved a total of 940 in-patient days with a total cost saving of approximately £350,000.00.

Conclusion: In the majority of patients spinal infection can be successfully treated. Disease severity dictates the duration of antibiotic treatment and whether surgery is required. Recurrent infection occurred in a number of patients with more significant past medical history and pre-existing risk factors. Finally, HIAS is extremely cost effective in this group of patients.

Aim: To assess the functional outcome following spinal infection.

Method: 42 patients who had been treated in our unit for primary spinal infection between 1995–2005 were identified. 33 who were still alive at the time of study, were sent postal questionnaires. Average length of follow up was 5.4 years (rang 0.6–10.5). The non-respondents were contacted by phone two weeks later. Overall 29 (88%) were traced.

Results: Mobility score dropped in 10 (34%) patients whilst domestic circumstances’ score dropped only in 1 (3.4%). Oswestry disability score averaged 18% (range 0–53%). 16 (62%) had mild or no disability, 7(27%) had moderate and 3 (12%) had severe disability. Neck disability index in all those with cervical spine infection was between 10–20% indicating mild disability. Hospital anxiety and depression score for anxiety was normal for 25 (86%) and that for depression was normal for 27(93%) patients. Ten point Visual Analogue Score (VAS) for pain intensity when doing the questionnaire averaged 1.3 (range 0–9) with 19 (66%) having no pain, 9 (31%) mild to moderate (1–5 score) and 1 (3%) having severe pain (6–10 score). Mean VAS over one week was 1.8(range 0–9) with 14(48%) having no pain, 13(45%) mild to moderate and 2 (7%) having severe pain. VAS for distress averaged at 1.8 (range 0–9), 22 (76%) patients were coping very well (8–10 score) and poor coping (0–4 score) was seen in 1 (3%).

Conclusion: Most patients after spinal infection return to activities of daily living with little or no pain and psychological sequelae. A proportion of patients however end up with moderate to severe disability, pain and psychological problems despite successful treatment of the primary infection.

To assess whether epidural steroid injection [ESI] is effective in the treatment of nerve root pathology caused by compression in the lumbar spine secondary to either spinal stenosis or disc prolapse, we carried out a prospective randomised controlled trial; patients were randomised either to ESI or Intramuscular steroid injection, with minimum two year follow-up.

Ninety two patients with symptoms, signs and radiological findings consistent with lumbar nerve root compression suitable for surgical decompression.

The main outcome measures were the Oxford Pain Chart over the first month, Oswestry Disability Index, and the need for surgery.

There was a significant reduction in pain early on after ESI compared with controls [p=< 0.004] between 10 and 35 days. There was no difference in the long term between the two groups and the rate of surgery in the two groups was not significantly different. Indeed the rate of surgery was higher in the ESI group than the control group [41% vs.31%] but this was not significant. A second ESI did not change the likelihood that surgery would be required.

Conclusion: ESI is effective for early pain relief for lumbar nerve root compression. However it does not change the natural history of the condition and does not reduce the ultimate need for surgery. It is probably effect to “buy time” in acute sciatica until improvement occurs naturally.

Study design: A prospective comparison of MRI findings with surgical findings in patients presenting to our spinal triage service with a prospective diagnosis of a lumbar disc herniation.

Objective: To investigate consistency between radiologists interpretation of MRI scans, and comparison between MRI and surgical findings, in an attempt to identify those patients suitable for percutaneous treatment.

Background: MRI has assumed a preeminent position in the diagnosis of lumbar disc prolapse.

Methods: 87 consecutive patients presenting with signs and symptoms suggestive of a lumbar disc prolapse that underwent an MRI and based on that a discectomy.

Results: Reliability tests show only fair agreement (k=0.36) between the radiologists and at best only moderate agreement (k=0.41) between the radiologists and surgical findings.

Conclusions: MRI is an excellent tool for diagnosis of a disc prolapse but does not appear to help in classifying discs suitable for percutaneous treatment.

Study design: A prospective comparison of MRI findings with surgical findings in patients presenting to our spinal triage service with a prospective diagnosis of a lumbar disc herniation.

Objective: To investigate consistency between Radiologists’ interpretation of MRI scans, and comparison between MRI and surgical findings, in an attempt to identify those patients suitable for percutaneous treatment.

Background: MRI has assumed a pre-eminent position in the diagnosis of lumbar disc prolapse.

Methods: 87 consecutive patients presenting with signs and symptoms suggestive of a lumbar disc prolapse that underwent an MRI and based on that a discectomy.

Results Reliability tests show only fair agreement (k=0.36) between the Radiologists and at best only moderate agreement (=0.41) between the Radiologists and surgical findings.

Conclusion: MRI is an excellent tool for diagnosis of a disc prolapse. MRI is poor at defining the character of a disc prolapse, and does not appear to help in classifying discs suitable for percutaneous treatment.

Study Design: Prospective randomized study.

Objectives: To compare the strategy of spinal fusion with that of rehabilitation for patients with chronic low back pain.

Methods: A multicentre trial of 349 candidates for spinal fusion (where both patient and surgeon were uncertain of the outcome) were randomised to either an operation that the surgeon considered was most appropriate for that patient or to an intensive rehabilitation programme. Rehabilitation was based on a 3 week (15 day) model of exercise therapy, spine stabilisation techniques and education using cognitive behavioural principles. Follow-up was at least 2 years from randomisation. The trial was 90% powered to show a 4 point difference between groups at α= 0.05. A full economic analysis is available.

Outcomes Measures: Oswestry Disability Index (ODI); the Shuttle Walking Test (SWT); SF-36 and EuroQol EQ-5D.

Results: 176 patients were randomized to surgery and 173 to rehabilitation. Demographic features including sex, age, diagnosis (spondylolisthesis, post-laminectomy syndrome, others) duration of back pain, smoking history, litigation, employment status, planned numbers of fused levels and baseline ODI were similar for both groups.

Results: For the surgery group the mean ODI improved from 46.6 (SD 14.5) to 34.9 (SD 21) at two years. For the rehabilitation group mean ODI improved from 44.8 (SD 14.8) to 36.2 (SD 20.6) at two years. For the surgery group the mean SWT improved from 254 (SD 209) to 350 (SD 244.8) at two years. For the rehabilitation group mean SWT improved from 247 (SD 185) to 310 (SD 203) at two years. For the surgery group the mean SF-36 Physical component score improved from 22.2 (SD 18) to 43.6 (SD 32.1) at two years. For the rehabilitation group the mean SF-36 Physical component score improved from 24.0 (SD 20.6) to 40.5 (SD 31.1) at two years.

Conclusions: This is a comparison of treatment strategies: There was no clinical or statistical difference in outcome between the strategy of spinal fusion and that of rehabilitation. Patients randomised to surgery (spinal stabilisation) and patients randomised to rehabilitation have indicated a treatment effect, but this may be due to natural history. The surgery results parallel those reported in other trials. At two years the treatment costs of the surgery arm were approximately twice those of the rehabilitation arm. The costs of rehabilitation depend on how many patients opt for surgery (22% in this trial). “Failed” non-operative treatment is commonly listed as an indication for surgery. “Failed” non-operative treatment should include intensive rehabilitation appropriately supported by the treating surgeon.

Study Design: A six-year retrospective analysis of all instrumented spinal fusions performed in the Nuffield Orthopaedic Centre and the John Radcliffe Hospital.

Objective: To assess the incidence of infection following instrumented spinal fusion, the nature of the infecting organisms and their subsequent management.

Subjects: All patients who had undergone removal of spinal metalwork were analysed for evidence of infection. The indications for removal of metalwork included proven deep infection, refractory postoperative pain or planned removal after thoraco-lumbar fracture.

Outcome Measures: Successful treatment of infection was documented when the patient was asymptomatic and inflammatory markers remained within normal limits following cessation of antibiotic therapy. Failure was documented when the patient had recurrent sepsis, refractory pain following removal of metalwork or died.

Results: 80 spinal infections following instrumented fusions were found between 1997 and 2003. 34 of the infecting organisms were propionibacteria, 19 were coagulase negative staphylococcus, 10 were staphylococcus aureus, 8 were methicillin resistant staphylococcus aureus, 3 were coliforms, 2 were proteus, 2 were diphtheroids, 1 was alpha haemolytic streptococcus and 1 was anaerobic streptococcus. 29 of these infections were polymicrobial. Of 55 patients who had metalwork removed secondary to pain, 20 patients had proven infection postoperatively (36.3%). Preoperative inflammatory markers failed to accurately predict the presence of infection for trauma patients. Our management of infection is removal of metalwork with six intraoperative samples sent for culture and histology specimens, followed by administration of at least six weeks of intravenous or oral antibiotic, depending on the organism and its antibiotic sensitivity. Prolonged treatment is used where inflammatory markers remain raised.

Conclusions: Infection of spinal implants presents different management problems to those which follow infected total joint replacement. The lack of specific clinical, laboratory and radiological findings in patients who are subsequently diagnosed as having infections associated with spinal instrumentation presents a challenging clinical problem. We found the most predictive sign of infection following instrumented fusion of scoliotic spines was postoperative pain. CRP and ESR were unreliable as predictors of infection.

Introduction and Aims: A multicentre trial of 349 patients of candidates for spinal fusion (where both patient and surgeon were uncertain of the outcome) were randomised to either an operation or to an intensive rehabilitation program. Rehabilitation was based on a three-week (15-day) model of exercise therapy and education using cognitive behavioural principles.

Method: The main outcome measures were the Oswestry Disability Index (ODI); Shuttle Walking Test; SF-36 and EuroQol EQ-5D recorded at baseline and six, 12 and 24 months after randomisation. The trial was 90%-powered to show a four-point ODI difference between groups at a= 0.05. Full economic analysis is available.

Results: Patients in both treatment arms made statistically significant improvements on all outcome measures between baseline and two-year follow-up. There was a small difference between the treatment arms favouring surgery on one of the main outcome measures, the Oswestry Disability Index; there were no statistically significant differences between the two treatment strategies for the rest. The difference in the change of score for the ODI was a decrease of 3.2 (C.I -7.3 – 0.9) in favour of surgery (p< 0.1), an improvement of 30 metres on the shuttle walking test in favour of the surgery group (p< 0.2), a difference of 0.01 on the Euroqol (p< 0.9) and an increase of 2.7 points on the SF-36 (p< 0.4).

The surgery results parallel those reported in other trials. At two years, the treatment costs of the surgery arm were approximately twice those of the rehabilitation arm. The costs of the rehabilitation strategy depend on how many patients opt to have surgery after rehabilitation (22% in this trial). This is a comparison of treatment strategies: there was no clinical or statistical difference in outcome between the strategy of spinal fusion and rehabilitation.

Conclusion: Patients randomised to both surgery (spinal stabilisation) and rehabilitation have indicated a treatment effect, but this may be due to natural history. ‘Failed’ non-operative treatment is commonly listed as an indication for surgery, this should only be considered once an intensive rehabilitation program backed by the treating surgeon has been tried.

Objective: To assess whether Webb Morley Instrumentation had satisfactory long term results.

Design: A retrospective review of 52 patients who underwent fusion and instrumentation with Webb Morley Instrumentation between 1991–1997.

Subjects: 52 patients were reviewed, 32 patients with idiopathic scoliosis who underwent isolated anterior fusion, 19 patients with neuromuscular scoliosis who underwent anterior and posterior surgery.

Outcome measures: Preoperative and postoperative radiographs, ISIS scans, and patient review. The in-patient notes were assessed for duration of surgery, blood loss, hospital stay and complications. Correction of Cobb angle and union were assessed.

Results: In the idiopathic group Cobb angle improved by 57%, apical rotation by 36% and tilt angle by 56%. There were no major complications and all united. The implant has a tendency to kyphose the spine, and an average of 7 degrees of kyphosis was seen across the implant. In the neuromuscular group Cobb angle improved by 52%, apical rotation by 21% and tilt angle by 57%. There was one asymptomatic pseudarthrosis, two rod breakages and two posterior rod dissociations. Only one patient complained of significant back pain.

Conclusions: Webb Morley instrumentation offers results as good as most other anterior implant systems. The flexibility of the rods may be a relative advantage, with a high union rate. Although the implant tends to kyphose the spine this has not been a problem clinically at follow-up of 4-11 years. This may help in design of future implants.

Objective: To assess the Universal Spine System and Kaneda Anterior Scoliosis System. Does one system have particular advantages over another?

Design: A retrospective review of patients with idiopathic scoliosis undergoing anterior fusion and instrumentation. The patients undergoing USS instrumentation were treated between 1994–1998, KASS patients 1997–2001.

Subjects: Thirty two consecutive patients were reviewed. Seventeen patients were in the USS group and 15 in the KASS group, 28/32 were female.

Outcome measures: Preoperative and postoperative radiographs, ISIS scans, and patient review. The in-patient notes were assessed for duration of surgery, blood loss, hospital stay and complications. Correction of Cobb angle and union were assessed.

Results: The patients in the KASS group had less flexible curves (correctability 45% vs. 53%). Despite this correction of Cobb angle was better in patients undergoing KASS instrumentation (38.0 degrees vs. 27.8 degrees, P=< 0.05). The secondary curves also improved more in the KASS group (55% vs. 29%, p=< 0.05). Complications occurred in 30%, but there was no difference between the two groups. There were no non-unions. In every other respect there was no difference between the groups for surgery time, blood loss, loss of correction or progression of secondary curve.

Conclusions: KASS instrumentation has better ability to correct spinal deformity in the short term. Further follow-up is required to assess long term results.

Objective: To assess early results with the KASS system for scoliosis correction. To assess lateral curvature, rotational correction and complications.

Design: The first 22 patients requiring anterior correction of scoliotic curves were retrospectively reviewed. Pre- and post-operative curve measurements were made with a Cobbometer. Topographical assessment (ISIS) scan was used to assess rotation and correction of the rib hump. The notes were reviewed to determine complications and time to discharge.

Subjects: Twenty-two patients: 18 idiopathic scoliosis (4 others); average age 15.4 years; 5 King One, 10 King Two, 6 King Three and one non-definable; 5 thoracic curves

Results: Average pre-op scoliosis 54.85 degrees

Average post-op scoliosis 19.4 degrees. Average correction 65%. One patient required second operation for long screws. Four self limiting rninor complications. Average time to discharge eight days

Conclusion: KASS instrurnentation is a safe, effective and reliable method to correct scoliotic curves including rotational deformities. It was not possible to correct the Cobb angle of purely thoracic curves as much as thoracolumbar curves. Cosmetic correction however has been excellent as demonstrated with ISIS. Long term review will be necessary to confirm that correction is maintained.