The purpose of this study was to evaluate whether concerns about the release of metal ions in metal-on-metal total hip replacements (THR) should be extended to patients with metal-bearing total disc replacements (TDR). Cobalt and chromium levels in whole blood and serum were measured in ten patients with a single-level TDR after a mean follow-up of 34.5 months (13 to 61) using inductively-coupled plasma mass spectrometry. These metal ion levels were compared with pre-operative control levels in 81 patients and with metal ion levels 12 months after metal-on-metal THR (n = 21) and resurfacing hip replacement (n = 36). Flexion-extension radiographs were used to verify movement of the TDR. Cobalt levels in whole blood and serum were significantly lower in the TDR group than in either the THR (p = 0.007) or the resurfacing group (p < 0.001). Both chromium levels were also significantly lower after TDR versus hip resurfacing (p < 0.001), whereas compared with THR this difference was only significant for serum levels (p = 0.008). All metal ion levels in the THR and resurfacing groups were significantly higher than in the control group (p < 0.001). In the TDR group only cobalt in whole blood appeared to be significantly higher (p < 0.001). The median range of movement of the TDR was 15.5° (10° to 22°). These results suggest that there is minimal cause for concern about high metal ion concentrations after TDR, as the levels appear to be only moderately elevated. However, spinal surgeons using a metal-on-metal TDR should still be aware of concerns expressed in the hip replacement literature about toxicity from elevated metal ion levels, and inform their patients appropriately

Determine the detection rate of modern spinal implants using the current technology. There is a paucity of data regarding detection rates of modern spinal implants using modern walk-through pulsed archway metal detectors (AMDs). No published reports compare detection capability with hand-held metal detectors (HHMDs). ex-vivo & in-vivo comparison of detection rates using AMD & HHMD (set to maximum DoT sensitivities), in patients of varying Body Mass Index (BMI), implants, implant mass/density and alloys. 40 patients with: lumbar disc replacement (CoCr) (n=8), cervical disc replacement (CoCr) (1), posterior deformity instrumentation (17), anterior deformity instrumentation (2), anterior reconstruction (2), PLIF (6), interspinous distraction device (1), anterior cervical plate (2) ALIF (1), All implants were titanium unless indicated. Mean metal mass was 98g (range 6g-222g). The AMD did not detect any instrumentation individually or in combination up to a titanium mass totalling 215g. The HHMD detected all instrumentation at a distance of 5cm; with the minimum mass being 2g. No implants were detected in patients by the AMD. The HHMD did not detect any anterior lumbar or thoracic surgical implants. It detected anterior cervical implants. The HHMD detected all posterior surgical implants. There was no significant relationship between detection, BMI, total metal mass, and metal density/segment. AMD detectors do not detect modern spinal implants. HHMD detect all modern posterior spinal implants; this has implications for patient documentation

Aims. Significant correction of an adolescent idiopathic scoliosis in the coronal plane through a posterior approach is associated with hypokyphosis. Factors such as the magnitude of the preoperative coronal curve, the use of hooks, number of levels fused, preoperative kyphosis, screw density, and rod type have all been implicated. Maintaining the normal thoracic kyphosis is important as hypokyphosis is associated with proximal junctional failure (PJF) and early onset degeneration of the spine. The aim of this study was to determine if coronal correction per se was the most relevant factor in generating hypokyphosis. Methods. A total of 95 patients (87% female) with a median age of 14 years were included in our study. Pre- and postoperative radiographs were measured and the operative data including upper instrumented vertebra (UIV), lower instrumented vertebra (LIV), metal density, and thoracic flexibility noted. Further analysis of the post-surgical coronal outcome (group 1 < 60% correction and group 2 ≥ 60%) were studied for their association with the postoperative kyphosis in the sagittal plane using univariate and multivariate logistic regression. Results. Of the 95 patients, 71.6% (68) had a thoracic correction of > 60%. Most (97.8%) had metal density < 80%, while thoracic flexibility > 50% was found in 30.5% (29). Preoperative hypokyphosis (< 20°) was present in 25.3%. A postoperative thoracic hypokyphosis was four times more likely to occur in patients with thoracic correction ≥ 60% (odds ratio (OR) 4.08; p = 0.005), after adjusting for confounding variables. This association was not affected by metal density, thoracic flexibility, LIV, UIV, age, or sex. Conclusion. Our study supports the ‘essential lordosis’ hypothesis of Roaf and Dickson, i.e. with a greater ability to translate the apical vertebra towards the midline, there is a commensurate lengthening of the anterior column due to the vertebral wedging. Cite this article: Bone Joint J 2020;102-B(4):513–518

Aims. To investigate metallosis in patients with magnetically controlled growing rods (MCGRs) and characterize the metal particle profile of the tissues surrounding the rod. Methods. This was a prospective observational study of patients with early onset scoliosis (EOS) treated with MCGRs and undergoing rod exchange who were consecutively recruited between February 2019 and January 2020. Ten patients were recruited (mean age 12 years (SD 1.3); 2 M:8 F). The configurations of the MCGR were studied to reveal the distraction mechanisms, with crucial rod parts being the distractable piston rod and the magnetically driven rotor inside the barrel of the MCGR. Metal-on-metal contact in the form of ring-like wear marks on the piston was found on the distracted portion of the piston immediately outside the barrel opening (BO) through which the piston rod distracts. Biopsies of paraspinal muscles and control tissue samples were taken over and away from the wear marks, respectively. Spectral analyses of the rod alloy and biopsies were performed to reveal the metal constituents and concentrations. Histological analyses of the biopsies were performed with haematoxylin and eosin staining. Results. Titanium (Ti), vanadium (V), and neodymium (Nd) concentrations in the biopsies taken near the wear marks were found to be significantly higher than those in the control tissue samples. Significantly increased Nd concentrations were also found in the tissues near the barrel of the MCGR. Chronic inflammation was revealed by the histological studies with fibrosis and macrophage infiltration. Black particles were present within the macrophages in the fibrotic tissues. Conclusion. Ti and V were generated mainly at the BO due to metal-on-metal contact, whereas the Nd from the rotor of the MCGR is likely released from the BO during distraction sessions. Phagocytotic immune cells with black particles inside raise concern regarding the long-term implications of metallosis. Cite this article: Bone Joint J 2020;102-B(10):1375–1383

Background. Carbon fibre (CF) instrumentation is known to be radiolucent and has a tensile strength similar to metal. A specific use could be primary or oligometastatic cancer where regular surveillance imaging and Stereotactic Radiotherapy are required. CT images are inherently more prone to artefacts which affect Hounsfield unit (HU) measurements. Titanium (Ti) screws scatter more artefacts. Until now it has been difficult to quantify how advantageous the radiolucency of carbon fibre pedicle screws compared to titanium or metallic screws actually is. Methodology. In this retrospective study, conducted on patients from 2018 to 2020 in SGH, we measured the HU to compare the artifact produced by CF versus Ti pedicle screws and rods implanted in age and sex matched group of patients with oligometastatic spinal disease. Results. Eleven patients were included in each group. We compared the change of HU between preoperative and postoperative cases of both CF & Ti screws, which clearly shows Ti screws scatter lot more artefacts than CF screws. We are proposing a CT artefact grading system from grade 0 to grade 4 based on the percentage change of HU for unequivocal understanding of the CT artefacts. Conclusion. This study clearly shows the artefacts produced by the metallic implants are significantly higher than the carbon fibre implants. Considering the efficacy of the RT and the increased life expectancy as a consequence, carbon instrumentation MAY BE superior to titanium or metallic instrumentation. The artefact grading system will help the clinicians in describing and planning where the artefacts need to be factorized

Introduction. Treatment of spinal metastatic disease has evolved with the advent of advanced interventional, surgical and radiation techniques. Spinal Oligometastatic disease is a low volume disease state where en bloc resection of the tumour, based on oncological principles, can achieve maximum local control (MLC). Hybrid therapy incorporating Separation surgery (>2mm clearance of the thecal sac) and Stereotactic Ablative Radiotherapy (SABR) offer an alternative approach to achieving MLC. Hybrid therapy is also a viable option in patients eligible for SBRT who have failed conventional radiation therapy. En-bloc surgery may be a suitable option for those patients who are ineligible for or have failed SBRT. A multidisciplinary approach is particularly important in the decision-making process for these patients. Metal free instrumentation is aiding the optimization of these surgeries. The authors present a supra-regional centre's experience in managing spinal oligometastases. Methods. Retrospective review of oligometastatic spinal disease at a supra-regional centre between 2017 and 2021. Demographics, operative course, complications and Instrument type are examined. Results. Demographics: 24 patients with mean age 53.8y (range 12–77), 44% (40y–59y), 40% (60y–69y); 51% Male. Histology: Breast, Renal and Sarcoma accounted for 16.7% each; Thyroid, Prostate and Chordoma accounted for 8.3% each. Primary disease 7%, Synchronous 15%, Metachronous 78%. Instrumentation: Carbon-fibre (85%), TiAl (11%), Non-Instrumented (3%). Separation Surgery (70%), En-bloc resection/Tomita surgery (30%); SABR/Proton Beam Planned: 70%. Average length of hospital stays 19.1 days; twenty patients required intensive care admission for an average 2.7 days. 30 Day Mortality 8.3% (n=2: COVID-19 during admission and ventriculitis post discharge), 1y Mortality – 16.7%, 3y Mortality – 25%; Synchronous Mortality 75% (n=3) at 3 years. 30 Day infection rate 3%; 1y infection rate 7%. 1 Non-instrumented case developed proximal junctional failure post proton beam therapy and required a vascularised fibular strut graft. 2-year Revision for Local Recurrence 5% (Revision at 23 months). Conclusion. There are very few case series of oligometastatic spinal disease due to the relatively new concept of adjuvant SABR and its limited availability. Solid tumours pre-dominated the histology in our series with metachronous disease being the most commonly operated disease state. 92% of cases were eligible for SABR. The majority (85%) of cases were performed with Carbon-fibre instrumentation and has been shown to be safe with no mechanical failures in this series. Infection rates are in keeping with patients requiring radical radiotherapy with 3% early and 7% late. 30-day mortality was 8.3%, 1y=16.7% and 25% at last follow up. Mortality, as expected, is highest within the synchronous disease group and should be operated on sparingly. With the current management strategy, there was no local recurrence at 1 year and excellent local recurrence rate at 2 years (5%). Although radical en bloc surgery carries significant morbidity, it should be considered in selective cases to achieve MLC. All Oligometastatic cases deserve extra consideration and specialist MDT as not all are suitable for SABR. Multimodal Hybrid therapy, incorporating less invasive surgical techniques and SABR, represents a paradigm shift in achieving MLC in oligometastatic spinal disease

Aims. We present a case series of five patients who had revision surgery following magnetic controlled growing rods (MGCR) for early onset scoliosis. Metallosis was found during revision in four out of five patients and we postulated a mechanism for rod failure based on retrieval analysis. Patients and Methods. Retrieval analysis was performed on the seven explanted rods. The mean duration of MCGR from implantation to revision was 35 months (17 to 46). The mean age at revision was 12 years (7 to 15; four boys, one girl). Results. A total of six out of seven rods had tissue metallosis and pseudo-capsule surrounding the actuator. A total of four out of seven rods were pistoning. There were two rods which were broken. All rods had abrasive circumferential markings. A significant amount of metal debris was found when the actuators were carefully cut open. Analytical electron microscopy demonstrated metal fragments of predominantly titanium with a mean particle size of 3.36 microns (1.31 to 6.61). Conclusion. This study highlights concerns with tissue metallosis in MCGR. We recommend careful follow-up of patients who have received this implant. Cite this article: Bone Joint J 2016;98-B:1662–7

Introduction. Low back pain is the leading cause of musculoskeletal disease and the biggest cause of morbidity worldwide. Approximately 40% of these are cases are caused by disease of the intervertebral discs (IVDs): the shock absorbing, flexible material located between the bones (vertebrae) along the length of the spine. In severe cases, the spine becomes unstable and it becomes necessary to immobilise or fix the joint in position using a lumbar cage spacer between in the IVD and metal pins with supporting plates in the vertebrae. This is a complex, expensive, major surgery and it is associated with complications, such as spinal fusion failure and inappropriate implant position. These complications have a dramatic impact on the quality of life of the affected patients and the burden to society and the healthcare system is exacerbated. Methods and Results. We present an in vitro study looking at the effect of our Bgel hydrogel on mesenchymal stem cells (MSCs) and their bone forming capacity within lumbar cages: devices used to space the bones apart in the fusion operation, as a mechanism to improve fixation and intra cage bone formation. MSCs were isolated from human hip joint, expanded, seeded within Bgel, cast into well inserts or lumbar cages and cultured for 4 weeks. Using 3D X-ray imaging micro computed tomography (μCT) scans we show that the MSC in the presence Bgel begin to mineralise within the lumbar cages. Histology is currently ongoing and will be presented at the meeting. Conclusion. This study shows the potential to improve current spinal fusion practices with the potential to reduce complications. Conflicts of interest: CS and CLM are named inventors on the patent for NPgel/BGel. Funded by the Medical Research Council and Versus Arthritis UK: SNiPER

Aim:. The aim of this study was test the amount of corrosion occurring at the (Ti) /cobalt chrome (CoCr) interface comparing this with Ti and Ti interfaces. This was compared with retrieved metal work visualised under a scanning electron microscope (SEM). Methods:. The interface of interest is the interface between rod and the screw. We investigated corrosion seen at that interface with a CoCr rod coupled to a Ti screw versus a Ti rod coupled to a Ti screw (6 screws were used) Implants were loaded according to the ASTM F2193 – 02 Standard Specifications and Test Methods for Components Used in the Surgical Fixation of the Spinal Skeletal System. Pitting potentials were monitored using cyclic potentiodynamic polarization tests (ASTM F2129 – 08 Standard Test Method for Conducting Cyclic Potentiodynamic Polarisation Measurements) to determine corrosion susceptibility. Retrieved implants were visualised under (SEM) to confirm corrosion. Results:. Mean fretting current for titanium and cobalt chrome was 7.94 (μA) and for titanium on titanium 5.89 (μA). The results of SEM showed evidence of fretting and galvanic corrosion. Discussion:. Cobalt chrome ions in hip implants have raised concern amongst the orthopaedic community. This study showed that metal ion production occurs due to fretting and galvanic corrosion. This corrosion is increased in cobalt chrome and titanium constructs but statistically more tests are required to confirm this. Further research is required to understand this interface as cobalt chrome ions pose a potential hazard to patients with their reproductive years ahead. Conflict Of Interest Statement: No conflict of interest

Aims

The aim of this study was to use diffusion tensor imaging (DTI) to investigate changes in diffusion metrics in patients with cervical spondylotic myelopathy (CSM) up to five years after decompressive surgery. We correlated these changes with clinical outcomes as scored by the Modified Japanese Orthopedic Association (mJOA) method, Neck Disability Index (NDI), and Visual Analogue Scale (VAS).

Aims

Magnetically controlled growing rods (MCGR) have been gaining popularity in the management of early-onset scoliosis (EOS) over the past decade. We present our experience with the first 44 MCGR consecutive cases treated at our institution.

Introduction. Recently published results suggest insertion of shorter screws in L5/S1 stand-alone anterior interbody fusion, fearing S1 nerve root violation. However, insertion of shorter screws led to screw fixation failure and new onset of S1 body fractures. Material and Methods. Retrospective review of patients with L5/S1 stand-alone anterior interbody fusion, focussing on screw length, radiological outcomes (especially metal work failure, screw fixation and S1 body fractures) and new onset of S1 nerve root irritation. Results. 38 patients were included (mean age 46.2±13.3 years, 21 females, 17 males). Fusion of the L5/S1 segment was performed in between 2003-2010; postoperative follow-up ranged from 2-24 months. 15 patients had multilevel surgery (7 multiple segmental fusion, 8 hybrid procedures). Screw length ranged from 20-30 mm. No patient had new postoperative S1 nerve root irritation. Interestingly, 2 patients out of the hybrid group had a new onset of L5 radiculopathy, concordant to the level of disc-replacement. Follow-up x-ray review showed no fracture of S1 body fractures in all patients. No evidence of screw loosening, migration or metal work failure was reported. Conclusion. In our opinion, this review showed that insertion of longer screws for stand-alone anterior interbody fusion in L5/S1 is safe. Longer screws offer better stabilization and seem to minimize risks like S1 body fractures. Short and long-term follow-ups were satisfactory regarding screw placement, migration and positioning of implants in all patients

With the identification of literature shortfalls on the techniques employed in intraoperative navigated (ION) spinal surgery, we outline a number of measures which have been synthesised into a coherent operative technique. These include positioning, dissection, management of the reference frame, the grip, the angle of attack, the drill, the template, the pedicle screw, the wire, and navigated intrathecal analgesia. Optimizing techniques to improve accuracy allow an overall reduction of the repetition of the surgical steps with its associated productivity benefits including time, cost, radiation, and safety.

Cite this article: Bone Joint J 2020;102-B(3):371–375.

Aim:. To compare the degree of deformity correction achieved using cobalt chromium versus titanium alloy rods in patients with Adolescent Idiopathic Scoliosis. Method:. A retrospective comparison of two cohorts of patients with Adolescent Idiopathic Scoliosis treated with posterior segmental pedicle screw fixation using either Titanium or Cobalt Chromium rods. The radiographs of 50 patients treated before 2009 (Ti group) and 50 patients after 2009 (CoCr group) were reviewed for changes in: Main Coronal Curvature Sagittal Balance (C7 Plumb Line) Kyphosis (T5-12). Results:. Thirteen were excluded because of incomplete radiographs. 38 patients received CoCr, 45 Ti and 4 patients received hybrid constructs. Correction rate of curves measuring >50 was significantly improved with CoCr (81% vs 69%, p=0.02). Sagittal balance was improved in both groups (CoCr 27.8, Ti 28.0 mm) but no significant difference was seen (p=0.84). Within the Ti group 12 patients moved for normal kyphosis (20–40) to abnormal (<20, >40) while 9 patients moved from abnormal to normal (p=0.66). Within the CoCr Group 10 patients were normalised while only 2 patients moved from normal to abnormal (p=0.04). Mean change in kyphosis showed a trend towards improved correction with CoCr (4.2 vs 2.9) but failed to reach significance (p=0.62). Discussion:. We have demonstrated that CoCr rods significantly improve coronal correction in patient with >50 curves. No difference in overall sagittal balance was seen between metal alloys. There is a trend towards better restoration of T5-12 kyphosis with CoCr however it is unclear if this small difference is clinically relevant. Conflict Of Interest Statement: No conflict of interest

To describe complications and reoperation rates associated with degenerative spinal deformity surgery. A retrospective review of prospectively collected data from a single spinal surgeon in the United Kingdom. A total of 107 patients who underwent surgery, of 5 or more levels, for primary degenerative kyphoscoliosis between 2006 and 2012 were identified. Clinical notes were reviewed and post-operative complications, reoperation rates, length of follow up and mortality were analysed. A total of 107 patients, average aged 66.5 years (range 52 – 85), with 80% women. 105 patients underwent posterior surgery, two patients required both anterior and posterior surgery. The average number of instrumented levels was 8.3; 10% 5 levels, 15% 6 levels, 11% 7 levels, 14% 8 levels, 15% 9 levels and 35% had fusions of 10 levels and above. 58% included fixation to sacrum or pelvis. 93% had a decompression performed and 30% had an osteotomy. There were 40 complications recorded within the follow-up period. Infection occurred in 7 patients (6.5%). All were successfully managed with debridement, antibiotic therapy and retention of implants. There were 4 dural tears (3.7%). One patient developed a post-operative DVT (0.9%). No patients sustained cord level deficits. Prevalence of mechanical complications requiring re-operation was 26% (28 patients). 5 patients (4.7) required revision surgery for symptomatic pseudarthrosis, 7 patients (6.5%) underwent revision fixation for metal work failure (broken rods/screw pull-out) and 16 patients (14.9%) underwent revision surgery to extend fixation proximally or distally due to adjacent segment disease (symptomatic proximal junction kyphosis 4.7%; osteoporotic fracture 3.7% and junctional/nerve root pain 6.5%). Overall reoperation rate was 32.5% at an average of 1.9 years following primary surgery (range 1 week–6 years). 37% patients remain on regular outpatient review (average 3.8 years following first surgery; range 2–6 years). 52% have been discharged after a mean follow-up of 2.3 years. 11 patients had died since their surgery (10.2%) at an average 4.1 years following their spinal surgery (range 1 –5.9 years). Overall complication rate was 37.3%. 32.5% of patients were re-operated for infective or mechanical complications. 52% of patients had been discharged at an average of 2.3 years following their surgery. 10.2% of patients had died within 6 years of surgery

To determine if the use of high density implants (i.e. high proportion of pedicle screws relative to number of spinal levels involved) causes significant loss of thoracic kyphosis and its effect on sagittal balance in adolescent idiopathic scoliosis. Retrospective analysis of pre and post-operative radiographs to assess sagittal balance and C7-L1 kyphosis angle. 17 patients (16 females, 1 male). All right sided single thoracic curves. All surgery performed by single surgeon (Senior author, ED). Comparison of pre and post operative sagittal balance and C7-L1 kyphosis angle. Assessment of implant density (i.e. proportion of pedicle screw relative to number of spinal levels involved in correction). 9 patients demonstrated improved sagittal balance following surgery. There was no significant difference (p value 0.83) between the pre and post op C7-L1 kyphosis angle. Mean angle pre op 28.9 (95% CI 20.3 to 37.5). Mean angle post op 29.6 (95% CI 22.2 to 37.0). No correlation identified between sagittal balance correction and kyphosis angle. Metal density ranged from 79-100%. Although the sample size in this series is modest, high density implants do not significantly affect the kyphosis angle in the operative management of adolescent idiopathic scoliosis in the thoracic spine

Introduction. Internal transpedicular fixation for the treatment of scoliosis develops quite fast and is widely used in clinical practice. The purpose of the study was to assess the efficacy of internal transpedicular fixation in treatment of patients with scoliosis. Material and methods. The system of internal transpedicular fixation (Vertebra Stabilization System Ø 5.5-6.35, OIM, Turkey) was employed for treatment of 50 patients with scoliosis of various severity. There was 83% of female patients aged from 15 to 23 years. Clinical and radiological methods were used for assessment of treatment results. Results. An angle of scoliotic deformity measured 40-60° in 20 cases, 60-100° in 21 patients, and more than 100° in 9 cases. Two-staged procedure was produced for two patients, and one-staged intervention for 33 cases. The length of in-patient treatment was five days. The patients could sit on the bed on the next day after the surgery, walk after 3 days, and were discharged from the hospital after 5 days for the follow-up. The deformity was corrected by 95-100% in the group of patients with scoliosis of 40-60°. The deformity was corrected by 85-90% in the group of patients with scoliosis of 60-100°. One-staged procedure allowed for 70-75% correction in patients with scoliosis more than 100°. Discussion and conclusion. The results of treatment showed no loss of correction at one-year follow-up. Patient aged more than 20 showed changing the deformity angle by 2-5° due to degenerative changes of the spine. No complications associated with inflammation of soft tissues, broken metal constructs were observed in this cohort of patients. Long-term follow-ups were evaluated from one to two years. All the patients were satisfied with their cosmetic and functional result

Statement of purpose. We review the current state of development of proton therapy and the implications for beam therapy in the management of primary bone tumours. Introduction. The principle of radiotherapy is to deliver a high dose, accurately, to the tumour. Conventional photon and proton therapy irradiates adjacent tissue significantly. This is reduced with intensity modulated proton therapy (IMPT). This has been demonstrably effective in treating tumours refractory to chemotherapy and conventional radiotherapy such as chrondrosarcomas and chordomas. Case Report. We present a patient with an isolated chondrosarcoma involving the anterior and posterior element of the L3 vertebral body with a significant soft tissue component displacing the IVC. The patient underwent a 2 stage en-bloc excision of the tumour: Stabilization was achieved by posterior L2-4 instrumented fusion with PEEK rods, an anterior PEEK cage and bone graft. Post-operatively the patient underwent 12 weeks of bed rest followed by rehabilitation. Due to pedicle involvement (giving a high risk of contamination) and the narrow clear margin found on histology the patient has been accepted for post-operative IMPT. Discussion. The high risk of contamination and the narrow margins presented an ideal case for post-operative IMPT. However, conventionally the stabilization would have been metallic, distorting the treatment mapping and the delivery of the IMPT, reducing any possible benefit. Thus, we used PEEK as it is proven to maintain its properties when subjected to a wide range of conditions while also being tolerant of, and not interfering with, most forms of radiation including proton therapy, maximising the chance of a positive outcome. One concern is that PEEK is less biomechanically stable then metal, hence the prolonged period of bed rest. Conclusion. This report discusses the current evidence for proton therapy while describing a successful technique for stabilization to facilitate delivery of proton treatment post-operatively

Following studies in 2007-08 comparing cervical discs devices, satisfaction and accuracy of operated and adjacent levels was observed with titanium devices. Patients were followed up and surgical assessments recorded. MRI with 12 patients were first assessed for imaging quality. Two independent radiologists scored twice sagittal and axial T2 – weighted images using the Jarvik four point scale. Statistical analysis was performed on operated and adjacent levels and between devices. Length of surgery, blood loss, approach and time of exposure to radiation were recorded. Patients were followed up at two years. BAGUERA C containing titanium metal allowed satisfactory visualization of the canal, exit foramina, cord and adjacent levels. PCM and PRODISC C visualization was significantly impaired at operated level and in both spinal cord and neural foramina. At adjacent levels, image quality was statistically poorer for those two devices. 6 patients were operated at C5-C6 and 6 at C6-C7. Mean age was 49. Approach was from the right, length of surgery and blood loss were: mean 46 min and 16.25 cc for BAGUERA C; mean 70 min and 27.5 cc for PCM and mean 63 min with 26.25 cc for PRODISC C. Exposure to radiation presented also significant difference between devices. Clinical outcomes reveal similar VAS and patient's satisfaction scores. Titanium device with polyethylene allow for satisfactory monitoring with adequacy in the assessment of neural decompression. BAGUERA C surgical outcomes indicate potential benefits that may be related to technique and simplicity of implantation

Statement of purpose. We review the current state of development of proton therapy and the implications for beam therapy in the management of primary bone tumours. Introduction. The principle of radiotherapy is to deliver a high dose, accurately, to the tumour. Conventional photon and proton therapy irradiates adjacent tissue significantly. This is reduced with intensity modulation proton therapy (IMPT). This has been demonstrably effective in treating tumours refractory to chemotherapy and conventional radiotherapy such as chrondrosarcomas and chordomas. Case Report. We present a patient with an isolated chondrosarcoma involving the anterior and posterior element of the L3 vertebral body with a significant soft tissue component displacing the IVC. The patient underwent a 2 stage en-bloc excision of the tumour: Stabilisation was achieved by posterior L2-4 instrumented fusion with Peek rods and screws, an anterior Peek cage and bone graft. Post-operatively the patient underwent 12 weeks of bed rest followed by rehabilitation. Due to pedicle involvement (giving a high risk of contamination) and the narrow clear margin found on histology the patient has been accepted for post-operative IMPT. Discussion. The high risk of contamination and the narrow margins presented an ideal case for post-operative IMPT. However, conventionally the stabilisation would have been metallic, distorting the treatment mapping and the delivery of the IMPT, reducing any possible benefit. Thus, we used Peek as it is proven to maintain its properties when subjected to a wide range of conditions while also being tolerant of, and not interfering with, most forms of radiation including proton therapy, maximising the chance of a positive outcome. One concern with Peek is that it is less biomechanically stable then metal, hence the prolonged period of bed rest. Conclusion. This report discusses the current evidence for proton therapy while describing a successful technique for stabilisation to facilitate delivery of proton treatment post-operatively. Ethics approval. None Audit/service standard in trust Ethics committee COREC number:. Interest Statement. None Local grant/National grant Commercial/industry support