Introduction: We report the result of cervical osteotomy in 11 patients using a controlled reduction technique and assess the safety and efficacy of this operation. Methods: Between 1993 and 2006, 11 patients with ankylosing spondylitis underwent correction of cervical kyphosis utilizing an extension osteotomy at the C7/T1 junction. The procedure was carried out under general anaesthesia with spinal cord monitoring. Lateral mass screws were placed from C3–C6 and thoracic pedicle screws placed from T2 to T5. After completion of the osteotomy, the reduction manoeuvre was carried out by the senior surgeon lifting the halo, while bilateral temporary malleable rods (fixed to cervical lateral mass screws) were allowed to pass through top loading thoracic pedicle screws, before tightening by the assistant when the desired position had been achieved. The temporary malleable rods were then replaced with definitive rods, thereby creating a solid internal fixation. A halo vest was maintained for 12 weeks to support the instrumentation and allow the fusion mass to develop.

Results: Surgery was performed on 10 males and one female. The mean age at surgery was 56 years (range 40–74). Duration of symptoms averaged 2.7 years (range 1–5 yrs). The average duration of surgery was 4.7 hours (range 3–6.5) with a mean blood loss of 1938cc (range 1000–3600). The mean follow up was 6.5 years (range 2–13). The mean pre-op chin brow vertical angle was 54º (range 20–70) reducing to 7º (range 2–20) at final follow-up. The mean pre-operative kyphotic angle was 19.2º reducing to minus 34º at final follow up. Restoration of normal forward gaze was achieved in all cases. No patient suffered spinal cord injury or permanent nerve root palsy.

Conclusion: Cervico-thoracic osteotomy is a potentially hazardous procedure. The technique described reduces the risk of translation during the reduction manoeuvre thereby reducing the risk of serious neurological injury.

Introduction: Conventional reduction techniques for high-grade isthmic spondylolisthesis do not address important anatomical constraints on the L5 and S1 nerve roots, thereby leading to a significant risk of neurological deficit. We describe a novel three-stage reduction technique carried out in one operative session that respects these anatomical constraints. We report the results in seven cases.

Methods: Between 2000 and 2006, four female and three male adolescents with high-grade spondylolisthesis (grade 3 or greater) underwent this 3 stage procedure which included: I) extensive posterior decompression of L5 and S1 nerve roots plus sacral dome osteotomy. II) anterior L5/S1 discectomy. III) reduction of spondylolisthesis with pedicle screw fixation and posterior lumbar interbody fusion using interbody cages. Somatosensory and motor evoked potentials were used during the procedure. Patients were followed up for a mean of 4 years (range1–6). Sagittal balance was restored and assessed by measuring sacral slope, lumbosacral angle, pelvic incidence and pelvic tilt.

Results: The mean age at surgery was 14.7 years (range 12–17) and average duration of symptoms was 13.7 months (range6–24). Mean operative time was 6.5 hours (range 5–8), with a mean blood loss of 2242cc (range1400–4200). The mean pre-op slip angle was 57°(range 45°–100°) and the mean post-op slip angle was 37.5°(range28°–57°). Anatomical reduction was achieved in six patients and one patient with spondyloptosis was reduced to grade 2. Sagittal balance was restored in all patients. There were no permanent neurological complications. One patient with grade 4 spondylolisthesis developed transient right L5 nerve root palsy which fully recovered within 3 months.

Conclusion: The safety and efficacy of this 3 stage reduction and stabilization procedure showed that immediate reduction of high grade spondylolisthesis with minimal risk of neurological deficit is possible. The procedure is technically demanding and should be performed by spinal surgeons familiar with the principles of anterior and posterior fusion.

Study Design: Prospective cohort study.

Objective: To assess the safety and efficacy of an intra-operative gamma probe in the surgical treatment of osteoid osteomas and osteoblastomas arising from the spine.

Summary of background data: Spinal osteoid osteomas and osteoblastomas are difficult to localise and may present adjacent to neural structures. Complete surgical excision of the nidus is a pre-requisite for curative resection.

Methods: All patients with a presumptive diagnosis of osteoid osteoma or osteoblastoma were investigated with plain radiography, computed tomography, magnetic resonance imaging and a technitium bone scan. Nine patients underwent surgical excision. 600 MBq of 99m technitium HMDP was administered intravenously three hours prior to surgery. A sterile cadmium telluride detector connected to a digital counter/ratemeter was used to detect gamma radiation emitted by the tumour intra-operatively to assist with localisation and confirmation of complete excision.

Results: Between October 1995 and September 2006, nine patients required surgical excision for seven osteoid osteomas and two osteoblastomas arising from the spine. All patients were between the ages of 9–31 years and presented with back or neck pain. All tumours involved the posterior elements of the spine. Three patients had previous failed treatment including CT-guided radiofrequency ablation and surgical excision. In all cases the counts per second (cps) dropped significantly following excision. For the osteoid osteoma cases, the mean cps dropped from 203.8 (range 60–515) to 72.5 cps (range 10–220) post-excision. For the osteoblastoma cases the mean cps dropped from 373.5 (range 67–680) to 40.5 cps (range 16–65) post-excision. Histological examination confirmed complete excision in all cases. The mean follow-up was 4.5 years (range 0.5 – 11 years). All patients reported disappearance of the characteristic pre-operative pain.

Conclusions: The use of an intra-operative gamma probe helps to localise and confirm complete excision of osteoid osteoma and osteoblastoma arising from the spine. Accurate localisation results in safe excision with maximal conservation of surrounding normal bone, whilst minimising operative time, blood loss, hospital stay and risk of recurrence.

Aim: The clinical and radiological outcomes of a prospective randomised controlled trial comparing Femoral Ring Allografts (FRA) to Titanium Cages (TC) for circumferential fusion are presented.

Methods: Eighty-three patients were recruited fulfilling strict entry requirements (> 6 months chronic discogenic Low Back Pain (LBP), failure of conservative treatment, one or two level discographically-proven discogenic pain). Five patients were excluded on technical infringements (unable to insert TC or FRA). From 78 patients randomised, 37 received FRA and 41 received TC. Posterior stabilisation was achieved with translaminar or pedicle screws. Patients completed the Oswestry Disability Index (ODI), Visual Analogue Scale (VAS) for back and leg pain, the Short-Form 36 (SF-36) pre-operatively and 6, 12 and 24 months post-operatively. Assessment of fusion was made by a panel of 6 individuals examining radiographs taken at the same specified time points.

Results: Clinical outcomes were available for all 83 patients (mean follow-up 28 months, range 24–75). Baseline demographic data showed no statistical difference between groups (p< 0.05). For patients receiving FRA, mean VAS (back pain) improved 2.0 points (p< 0.01), mean ODI improved 15 points (p=< 0.01), and mean SF-36 scores improved by > 11 points in 6 of 8 domains (p< 0.03). For patients receiving TC, mean VAS improved 1.1 points (p=0.004), mean ODI improved 6 points (p=0.01), and SF-36 improved significantly in only two of eight domains. Revision procedures and complications were similar in both groups. For the FRA group, 27 levels were fused from a total of 42 assessed (64.2%). For the TC group, 33 levels were fused from a total of 55 assessed (60%). This difference was not statistically significant p> 0.2.

Conclusion: The use of FRA in circumferential lumbar fusion was associated with superior clinical outcomes when compared to those observed following the use of TC. Both groups had similar fusion rates.

Introduction: Patient questionnaires permit a direct measure of the value of care as perceived by the recipient. The Scoliosis Research Society outcomes questionnaire (SRS-22) has been validated as a tool for self-assessment. We investigated the correlation between SRS-22 and a detailed radiological outcome two-years following anterior correction of ThoracoLumbar Adolescent Idiopathic Scoliosis (TL-AIS).

Methods: The SRS-22 questionnaire was completed by 30 patients two-years following anterior correction of TL-AIS. Pre-operative, post-operative and two-year follow-up radiographs of all 30 patients were assessed. The following parameters were measured at each time point: 1) Primary Cobb angle, 2) Secondary Cobb angle, 3) Coronal C7-midsacral plumb line, 4) Apical Vertebra Translation (AVT) of primary curve, 5) AVT of the secondary curve, 6) Upper instrumented vertebra (UIV) translation, 7) UIV tilt angle, 8) Lower instrumented vertebra (LIV), 8) LIV tilt angle 9) Apical Vertebra Rotation (AVR) of the primary curve, 10) Sagittal C7-posterior corner of sacrum plumb line 11) T5–T12 angle, 12) T12-S1 angle, 13) shoulder height difference. The percentage improvements for each were noted. Correlation was sought between Total SRS score, each of the five individual domains and various radiographic parameters listed above by quantifying Pearson’s Correlation Coefficient (r).

Results: Percentage improvement in primary Cobb angle (r = 0.052), secondary Cobb angle (r = 0.165) and AVT of the primary curve (r = −0.353) showed little or no correlation with the SRS-22 total score or any of its five domains. Significant inverse correlation was found between the UIV tilt angle at two years and the SRS-22 (r = −0.516). Lateral radiographs however showed little or no correlation between thoracic kyphosis (r = 0.043) and SRS-22.

Conclusion: The SRS-22 outcomes questionnaire does not correlate with most of the radiographic parameters commonly used by clinicians to assess patient outcome.

Study Design: Economic evaluation alongside a prospective, randomized, controlled trial from a 2-year NHS perspective.

Objective: To determine the cost-effectiveness of Titanium Cages (TC) compared to Femoral Ring Allografts (FRA) in circumferential lumbar fusion.

Summary of background data: A randomised controlled trial has shown the use of TC to be clinically inferior to the established practice of using FRA in circumferential lumbar fusion. Health economic evaluation is urgently needed to justify the continued use of TC, given that this treatment is less effective and, all things being equal, more costly than FRA.

Methods: Eighty-three patients were randomly allocated to receive either the TC or FRA as part of a circumferential lumbar fusion between 1998 and 2002. NHS costs related to the surgery and revision surgery needed during the trial period were monitored and adjusted to the base year (2005/6 pounds sterling). The Short Form-6D (SF- 6D) was administered preoperatively and at 6, 12 and 24 months in order to elicit patient utility and subsequently Quality-Adjusted Life Years (QALYs). Return to paid employment was also monitored. Bootstrapped mean differences in discounted costs and benefits were generated in order to explore cost-effectiveness.

Results: A significant cost difference of £1,942 (95% CI £849 to £3,145) in favour of FRA was found. Mean QALYs per patient over the 24 month trial period were 0.0522 (SD 0.0326) in the TC group and 0.1914 (SD 0.0398) in the FRA group, producing a significant difference of 0.1392 (95% CI 0.2349 to 0.0436). With regard to employment, incremental productivity costs were estimated at £185,171 in favour of FRA.

Conclusion: From an NHS perspective, the trial data show that TC is not cost-effective in circumferential lumbar fusion. The use of FRA was both cheaper and generated greater QALY gains. FRA patients reported a greater return to work rate.

Intra-Discal Electrothermal Therapy (IDET) has been proposed as a treatment for chronic discogenic low back pain. Reports from prospective outcome studies demonstrate statistically significant improvements, but to date there are no published randomized controlled trials assessing efficacy when compared to a placebo group.

Ethical Committee approval was obtained prior to the study. Patients with chronic low back pain who failed to improve with conservative therapy were considered for the study. Subjects had one or two level symptomatic disc degeneration as determined by provocative CT/discography. Patients were excluded if there was > 50% loss of disc height or previous back surgery. Fifty-seven patients were randomized with a 2:1 (IDET: Placebo) ratio, 38 to the active IDET arm and 19 to the sham procedure (placebo). In all cases the IDET catheter was positioned under sedation to cover at least 70% of the annular tear defined by the CT/discogram. An independent technician connected the catheter to the generator and either delivered electrothermal energy (active group) or did not (sham group). Both surgeon and patient were blinded to the treatment. Patients followed a standard rehabilitation programme.

Low Back outcome score (LBOS), Oswestry Disability Index (ODI), SF-36 questionnaire, Zung Depression Index (ZDI) and Modified Somatic Perceptions Questionnaire (MSPQ) were measured at baseline and 6 months. Successful outcome was defined as: no neurological deficit resulting from the procedure, improvement in LBOS of > 7 points, improvements in SF-36 subsets (pain/disability, physical functioning and bodily pain).

Two subjects withdrew (both IDET). Baseline demographic data, employment and worker’s compensation status, sitting tolerance, initial LBOS, ODI, SF-36, ZDI and MSPQ were similar for both groups. No neurological deficits occurred as a result of either procedure. No subject in either treatment arm showed improvement of > 7 points in LBOS or specified domains of the SF-36. Mean ODI was 41.4 at baseline and 39.7 at 6 months for the IDET group compared to 40.7 at baseline and 41.5 at six months for the Placebo group. There was no significant change in ZDI or MSPQ for either group. No subject in either treatment arm met criteria for successful outcome. Further analysis showed no significant change in outcome measures in either group at six months.

In conclusion, this study demonstrates no significant benefit from IDET over placebo.

Introduction We report the two-year clinical outcome of a prospective randomised trial comparing Femoral Ring Allograft (FRA) to a Titanium Cage (TC) in circumferential lumbar spinal fusion.

Methods 83 patients recruited to the study fulfilled strict entry requirements (> 6 months chronic discogenic low back pain, failure of conservative treatment, one or two-level discographically proven discogenic pain source). 38 patients were randomised to receive FRA, 45 patients were randomised to receive TC. Posterior stabilisation was achieved with translaminar or pedicle screws. Patients completed questionnaires including Oswestry Disability Index (ODI), Visual Analogue Scale (VAS) and the Short-Form 36 (SF-36) pre-operatively and 6, 12 and 24 months post-operatively.

Results Results were available for all 83 patients with a mean follow-up of 26.5 months (range 24–75 months). Baseline demographic data (age, sex, smoking history, number of operated levels, pre-operative outcome measures) showed no statistical difference between groups (p< 0.05). For patients receiving the FRA, mean VAS (back pain) improved 2.0 points (p=0.01), mean ODI improved 14 points (p=< 0.01), and mean SF-36 scores improved by > 11 points in all domains (p< 0.03) except general health and emotional role. For patients receiving the TC, mean VAS improved 1.2 points (p=0.002), mean ODI improved 5 points (p=0.02); SF-36 improved significantly in only one of eight domains (bodily pain).

Discussion Clinical outcome following circumferential lumbar fusion with FRA readily achieves the accepted mean clinically important differences (MCID). Fusion with TC does not achieve the MCID. The use of TC for circumferential lumbar fusion appears not to be justified.

Background: Anterior scoliosis correctional surgery can result in screw pull out or pedicular fracture. This is more common in stiff curves where the instrumentation extends to the smaller, higher, thoracic levels. The fracture/intra-operative pull out usually occurs during the reduction maneuver. In all of our cases the curve was reduced in the standard cranial to caudal direction using a cantilever maneuver. We describe a salvage technique using circlage wires that can be used for this problem. We present seven cases and the final outcome.

Methods: The technique involves placing a longer screw into the damaged vertebrae so it protrudes 5mm proud. A 1.25mm circlage wire is then cut to length and passed around the tip of the screw. It is then looped in a figure of eight passed under the rod and tightened around the respective pedicle screw head. A case record and x- ray review of seven procedures performed was then carried out. The age of the patients was between 14 and 41 years (mean 20) at surgery. The pre-operative Cobb was between 72 and 43 (mean 58). One curve was flexible with a flexibility index of 70% but the remainder was stiffer (range 34%–40%). There was one thoracolumbar curve with a T11 fracture. All other curves were thoracic and the fracture levels were T5, T7, T7, T6+7, T6+7+8, and T6+7+8 respectively. Four out of seven were braced post operatively for three months. The Cobb angle over the instrumented levels immediately post surgery and at final follow up was measured. The technique was deemed to be successful if no significant loss of correction occurred.

Results: The technique held position in six out of seven of the subjects. The average loss of position in these patients was two degrees (range 0–4). In one subject the curve went from 28 degrees immediately post operatively to 38 degrees over 2 years. The four month post operative x ray showed no loss of position suggesting that this loss of position may not be due to the fracture. This patient remained pleased with his cosmetic result and went from 72 degrees pre operatively to 38 degrees at 2 year follow up.

Conclusion: Care should be taken in patients with stiff proximal curves. The use of larger 8mm screws may decrease pull out and consideration may be given to caudal to cranial reduction in some cases. Circlage wire rescue is a useful salvage procedure for inter-operative fracture or screw pull out during anterior scoliosis correction.

Objectives: Posterolateral annular lesions were experimentally induced and allowed to mature for 12 weeks in the intervertebral discs of sheep. IDET was performed in an attempt to denervate and repair the annular lesion. The histological and immunohistochemical effects of IDET were studied.

Summary of Background Data: IDET continues to be used as a minimally-invasive treatment for chronic discogenic low back pain, with success rates reported in up to 70% of cases. The mechanism of action by which IDET exerts its effect is poorly understood. Proposed mechanisms include the contraction of collagen and the coagulation of annular nociceptors. An ovine model was used firstly to induce a posterolateral annular lesion, secondly to assess the innervation of such a lesion, and thirdly to assess the effect of IDET on this innervation.

Methods: Posterolateral annular incisions were made in 40 lumbar discs of 20 sheep. Twelve weeks were allowed for each annular lesion to mature. IDET was then performed in the disc with the posterolateral annular tear and in another control level. IDET was performed using a modified intradiscal catheter. Temperatures were recorded in the nucleus (T_N) and the posterior annulus (T_PA). The spines were harvested at predetermined intervals up to eighteen months. Histological sections of the discs were graded for disc morphology to assess degeneration and immunohistochemical staining to assess potential denervation.

Results: Vascular granulation tissue consistent with a healing response was observed in the posterior annular tear of all incised discs from 12 weeks. PGP 9.5 positive nerve fibres were clearly identified in the adjacent periannular tissue and the outer few lamellae of the posterior annulus. During the IDET procedure the mean maximaximum T_PA was 63.6°C and the mean maximaximum T_N was 67.8°C. At sacrifice the number of nerve fibres identified in the posterior annular tear was the same for those specimens that had undergone IDET and those that had not. From six weeks after IDET there was evidence of thermal necrosis in the inner annulus and adjacent nucleus but sparing the periphery of the disc.

Conclusions: IDET delivered at 90°C in the sheep consistently heated the posterior annulus and the nucleus to a temperature normally associated with coagulation of nociceptors and collagen contraction. IDET did not denervate the posterior annular lesion. Thermal necrosis was observed within the inner annulus and adjacent nucleus from six weeks after IDET. The reported benefits from IDET appear to be related to factors other than denervation and repair.

Introduction: Intra-Discal Electrothermal Therapy (IDET) has been used to treat chronic discogenic low back pain. A novel intradiscal decompression catheter has been developed to reduce local disc bulging in cases of contained prolapse. This new catheter is inserted percutaneously into a disc and advanced under radiographic control into a postero-lateral position targeting the herniation. The decompression catheter uses more focused heating and higher temperatures than previous devices and is intended to provide a local decompression of the disc through a thermally mediated reduction in nuclear volume. The purpose of this study was to investigate changes in internal stress profiles following use of the new catheter.

Methods: Five cadaveric lumbar ‘motion segments’ were dissected from two spines (age 64–84 yrs). Each segment was compressed, normally to 1 kN, while a miniature pressure transducer was withdrawn from posterior to anterior across the mid-sagittal diameter of the disc producing a baseline stress profile. A decompression catheter was inserted into the disc and its position confirmed with plain radiography. The temperature of the catheter was increased to 90°C over a period of 14 minutes. Stress profiles were then repeated.

Results: Stress profiles in three of the five segments showed changes consistent with degenerative change. In these discs stress profiles following ‘treatment’ showed up to a 35% reduction in the magnitude of stress peaks in the posterior annulus. There was very little change in the distribution of stress in the two non-degenerate discs. Stress in the nucleus appeared unchanged in all discs.

Conclusions: Treatment of degenerate discs with the decompression catheter lead to a measurable alteration in annular stress peaks associated with degenerative discs, while non-degenerate discs were unaffected. These preliminary findings of an ongoing study suggest that the novel decompression catheter has a biomechanical effect in certain classes of disc.

Introduction: Intra-Discal Electrothermal Therapy (IDET) has been proposed as a treatment for chronic discogenic low back pain. Reports from prospective outcome studies demonstrate statistically significant improvements, but to date there are no published randomized controlled trials assessing efficacy versus a placebo group.

Methods: Ethical committee approval was obtained prior to the study. Patients with chronic low back pain who failed to improve with conservative therapy were considered for the study. Inclusion criteria included the presence of one or two level symptomatic disc degeneration with posterior or posterolateral annular tears as determined by provocative CT/discography. Patients were excluded if there was > 50% loss of disc height or previous back surgery. Fifty-seven patients were randomized with a 2:1 (IDET: Placebo) ratio, 38 to the active IDET arm and 19 to the sham procedure (placebo). In all cases the IDET catheter was positioned under sedation to cover at least 70% of the annular tear defined by the CT/ discogram. An independent technician connected the catheter to the generator and either delivered electrothermal energy (active group) or did not (sham group). Both surgeon and patient were blinded to the treatment. Patients followed a standard post-procedural rehabilitation programme.

Outcome Measures: Low Back Outcome Score (LBOS), Oswestry Disability Index (ODI), SF-36 questionnaire, Zung Depression Index (ZDI) and Modified Somatic Perceptions Questionnaire (MSPQ) were measured at baseline and 6 months. Successful outcome was defined as: No neurological deficit resulting from the procedure, improvement in LBOS of > 7 points, improvements in SF-36 subsets (pain / disability, physical functioning and bodily pain)

Results: Two subjects withdrew from the study (both IDET). Baseline demographic data, employment and worker’s compensation status, sitting tolerance, initial LBOS, ODI, SF-36, ZDI and MSPQ were similar for both groups.

No neurological deficits occurred as a result of either procedure. No subject in either treatment arm showed improvement of > 7 points in LBOS or specified domains of the SF-36. Mean ODI was 41.4 at baseline and 39.7 at 6 months for the IDET group compared to 40.7 at baseline and 41.5 at six months for the Placebo group. There was no significant change in ZDI or MSPQ scores for either group.

Discussion: No subject in either treatment arm met criteria for successful outcome. Further analysis showed no significant change in outcome measures in either group at six months. This study demonstrates no significant benefit from IDET over placebo.

We studied prospectively 22 young athletes who had undergone surgical treatment for lumbar spondylolysis. There were 15 men and seven women with a mean age of 20.2 years (15 to 34). Of these, 13 were professional footballers, four professional cricketers, three hockey players, one a tennis player and one a golfer. Preoperative assessment included plain radiography, single positron-emission CT, planar bone scanning and reverse-gantry CT. In all patients the Oswestry disability index (ODI) and in 19 the Short-Form 36 (SF-36) scores were determined preoperatively, and both were measured again after two years in all patients. Three patients had a Scott’s fusion and 19 a Buck’s fusion.

The mean duration of back pain before surgery was 9.4 months (6 to 36). The mean size of the defect as determined by CT was 3.5 mm (1 to 8) and the mean preoperative and postoperative ODIs were 39.5 (sd 8.7) and 10.7 (sd 12.9), respectively. The mean scores for the physical component of the SF-36 improved from 27.1 (sd 5.1) to 47.8 (sd 7.7). The mean scores for the mental health component of the SF-36 improved from 39.0 (sd 3.9) to 55.4 (sd 6.3) with p < 0.001. After rehabilitation for a mean of seven months (4 to 10) 18 patients (82%) returned to their previous sporting activity.

Objective: To assess the clinical and radiological outcome of isolated hemivertebrae and multiple vertebral anomalies in the very young.

Design: A cohort of patients with congenital scoliosis were identified on antenatal ultrasound and followed prospectively from twenty weeks in-utero (IU) for a mean of two years (range IU – five years).

Subjects: Twenty fetuses with congenital hemivertebrae were identified from 16, 000 routine antenatal scans over a five-year period. Each was X-rayed at six weeks and investigated for renal and cardiac abnormalities.

Outcome Measures: Clinical assessment included trunk balance, neurological abnormality and associated congenital abnormalities. Radiological assessment of curve magnitude and curve progression was performed using the Cobb method. The potential for progression (based on site, degree of incarceration, growth potential and presence of a congenital bar) was assessed. In all cases a clinical and radiological assessment was made at maximal follow-up.

Results: One of the twenty fetuses aborted spontaneously at 23 weeks, three remain in-utero, leaving 16 live births. Thirteen of 20 had an isolated hemivertebra, and seven of twenty had multiple vertebral abnormalities. Two fetuses had renal agenesis, two had VATER’s syndrome and one had rib and abdominal wall abnormalities. The mean antenatal Cobb angle was 30°. IU curve progression was noted in three. Seven of the 16 live births required surgery based on curve magnitude, curve progression, truncal imbalance and the potential for progression. Surgery included anterior and posterior convex hemi-epiphyseodesis in two, and hemivertebra excision with fusion in five. The mean pre-operative Cobb angle was 36° (range 25–42) reducing to a mean of 21° (range 0–45) at maximal follow-up.

Conclusions: Multiple vertebral abnormalities were more commonly associated with renal and cardiac abnormalities. If associated with the oligohyramnios sequence the fetus appeared to be at high risk. In general US detected isolated fetal hemivertebrae carry a good prognosis, nevertheless 38% of these cases at our institution underwent surgery within the first two years of life.

Objective: To determine if a porous, coralline-derived hydroxyapatite block (ProOsteon 500^TM, Interpore, Irvine, CA) is a suitable substitute for tricortical iliac crest autograft in cervical interbody fusion.

Design: A prospective randomised trial with two-year follow-up comparing clinical and radiographic outcomes in patients receiving either iliac crest or hydroxyapatite grafts in cervical interbody fusion.

Subjects: Twenty-nine patients undergoing cervical fusion and anterior plating were randomised to receive either iliac crest (Group I) or hydroxyapatite (Group II) interbody grafts. Fourteen patients (19 grafts) in Group I and twelve patients (18 grafts) in Group II were available for final analysis. Both groups were similar with respect to age, sex, diagnosis and levels fused.

Outcome Measures: The SF-36 and Oswestry Disability Index were used to measure clinical outcome. Post-op and final follow-up radiographs were analysed for graft fragmentation, loss of height, loss of angular alignment and hardware failure to assess structural integrity of the graft. Computed or plain tomography was used to evaluate fusion.

Results: Groups I and II demonstrated improvement in preoperative scores for bodily pain (p=. 016 and. 016 respectively) and physical functioning (p=. 050 and. 016 respectively) at final follow-up. There was no significant difference in SF-36 and Oswestry scores between the two groups. Successful radiographic fusion was similar in both groups (79% in Group I and 76% in Group II). Graft fragmentation occurred in 89% of the hydroxyapatite grafts and 11% of the autografts (p=. 001). Greater than 2mm of graft height and 3° of segmental lordosis were lost in 55% of hydroxyapatite grafts vs. 11% of autografts (p=. 009). One patient in Group II and none in Group I required revision surgery for graft failure. The high rate of early radiographic failure in the hydroxyapatite grafts prompted suspension of further enrolment in the clinical trial.

Conclusions: ProOsteon 500 coralline hydroxyapatite blocks do not possess adequate structural integrity to resist axial loading and maintain disc height or segmental lordosis during cervical interbody fusion.

Objective: To evaluate the efficacy and safety of an expandable titanium cage for anterior column replacement after partial or total corpectomy in the thoracolumbar spine.

Design: A retrospective study evaluating the clinical and radiographic outcome following insertion of a novel implant.

Subjects: Twenty-three patients with anterior column insufficiency secondary to tumour, fracture, and infection were treated with a vertebral replacement capable of rapid and controlled in-situ expansion. Follow up consisted of a clinical and radiological review at a mean of 15.2 months (range 6–20 months).

Outcome Measures: The clinical outcome was measured by the degree of pain relief post-operatively, the ability to ambulate and the reliance on walking aids. Neurological deficit was measured using the Frankel Grade. Radiological follow-up compared preoperative radiographs with those taken at maximal follow-up. The degree of kyphosis and the degree of subsidence was measured.

Results: Twenty-three patients with a mean age of 43.6 years (range 20–72) underwent surgery. Indications included metastatic tumour in eight, acute fractures in five, infection in four, degenerative conditions in three, post-traumatic kyphosis in two and pseudathrosis in one. Nineteen patients underwent a single-level corpectomy and four patients a two-level corpectomy. Fourteen patients had a significant neurological deficit preoperatively. Supplementary instrumentation was used in 20 of 23 cases (anterior in nine, posterior in eleven). Excellent pain relief was observed in 19. Ten of 14 patients showed neurological improvement. Eleven patients improved their ambulatory status. There was no hardware failure. An average correction of 110 of kyphosis was observed. The average subsidence was 1.3 mm (range 0.2–2.3).

Conclusions: The use of an expandable vertebral body replacement with supplementary instrumentation following corpectomy appears to be safe and efficacious in correcting kyphosis. This implant appears to have a high resistance to subsidence.

Objective: To assess the clinical outcome and return to sport following surgical treatment of spondylolysis in young sporting individuals.

Design: A prospective outcome analysis of consecutive surgically treated cases of lumbar spondylolysis in young sporting individuals.

Subjects: Twenty-two young sports persons (15M: 7F) with a mean age of 20.2 years (range 15–34 years) were surgically treated for radiographically confirmed spondylolysis between 1994 and 1999. Eleven patients were professional footballers and four were professional cricketers. Pre operative assessment included plain X-rays, SPECT imaging with planar bone scan and reverse gantry CT scans. All subjects had pre-operative Oswestry Disability Index (ODI) and SF36 scores recorded. Eighteen patients underwent Buck’s fusion and four patients underwent Scott’s fusion. A graduated exercise regime was commenced at 12 weeks. At two year follow-up nineteen patients had ODI and SF36 scores recorded.

Outcome Measures: The clinical outcome in individual patients supported by statistical analysis of the pre operative and post-operative data was performed using SPSS (ver 10). Return to the sporting activity at the previous level was regarded as a successful outcome.

Results: Eleven patients had bilateral spondylolysis at L5. Twenty patients had positive uptake on SPECT imaging and the remaining two were diagnosed to have lysis on CT scans alone. The average duration of back pain before the patients underwent surgery were 8.4 months (range 3–36 months). The mean lysis defect determined by CT was 3.5 mm (range 1–8 mm). The mean pre-operative and post-operative ODIs were 40.5 and 12.4 respectively (SEpreop = 2.06 and SEpostop = 3.05). The mean scores of physical health component of SF36 improved from 27.1 to 47.8 (SEmean = 1.1 and 1.7 respectively). The mean scores of mental health component of SF36 improved from 39.1 to 55.3 (SEmean = 0.9 and 1.4 respectively) [P < 0.001]. Eighteen patients returned to their previous active sporting career following an average of seven months of rehabilitation (range 4–10 months).

Conclusions: The surgical repair of bilateral spondylolysis with Buck’s fusion in professional sportsmen and women results in a significant improvement in Oswestry Disability scores (P< . 001) and in all domains of SF36 health questionnaire (P< . 001). 90% return to active sport seven months following surgery.

We have recently described an extended lateral approach to the hindfoot for the operative treatment of displaced intra-articular fractures of the calcaneum. It has the advantage of avoiding damage to the sural nerve and preserving blood supply to allow prompt healing.

We dissected 15 formalin-preserved cadavers, taking photographs to show the structures of the posterolateral aspect of the hindfoot and ankle. We describe a superficial and a deep triangle: the deep triangle contains a constant posterior peroneal artery which supplies the skin of the posterolateral heel. An approach designed to expose the sural nerve will divide this important artery and cause ischaemia of the posterior skin. The extended lateral approach elevates the sural nerve in a thick flap and preserves the blood supply of the skin.

We have reviewed 150 consecutive patients after the use of this approach to study the indications for operation, the quality of wound healing, any damage to the sural nerve and other complications. We recommend the careful use of this approach. Our understanding of its anatomical basis has allowed us to widen the indications for its use.