En bloc resection for primary bone tumours and isolated metastasis are complex surgeries associated with a high rate of adverse events (AEs). The primary objective of this study was to explore the relationship between frailty/sarcopenia and major perioperative AEs following en bloc resection for primary bone tumours or isolated metastases of the spine. Secondary objectives were to report the prevalence and distribution of frailty and sarcopenia, and determine the relationship between these factors and length of stay (LOS), unplanned reoperation, and 1-year postoperative mortality in this population. This is a retrospective study of prospectively collected data from a single quaternary care referral center consisting of patients undergoing an elective en bloc resection for a primary bone tumour or an isolated spinal metastasis between January 1st, 2009 and February 28th, 2020. Frailty was calculated with the modified frailty index (mFI) and spine tumour frailty index (STFI). Sarcopenia, determined by the total psoas area (TPA) vertebral body (VB) ratio (TPA/VB), was measured at L3 and L4. Regression analysis produced ORs, IRRs, and HRs that quantified the association between frailty/sarcopenia and major perioperative AEs, LOS, unplanned reoperation and 1-year postoperative mortality. One hundred twelve patients met the inclusion criteria. Using the mFI, five patients (5%) were frail (mFI ³ 0.21), while the STFI identified 21 patients (19%) as frail (STFI ³ 2). The mean CT ratios were 1.45 (SD 0.05) and 1.81 (SD 0.06) at L3 and L4 respectively. Unadjusted analysis demonstrated that sarcopenia and frailty were not significant predictors of major perioperative AEs, LOS or unplanned reoperation. Sarcopenia defined by the CT L3 TPA/VB and CT L4 TPA/VB ratios significantly predicted 1-year mortality (HR of 0.32 per one unit increase, 95% CI 0.11-0.93, p=0.04 vs. HR of 0.28 per one unit increase, 95% CI 0.11-0.69, p=0.01) following unadjusted analysis. Frailty defined by an STFI score ≥ 2 predicted 1-year postoperative mortality (OR of 2.10, 95% CI 1.02-4.30, p=0.04). The mFI was not predictive of any clinical outcome in patients undergoing en bloc resection for primary bone tumours or isolated metastases of the spine. Sarcopenia defined by the CT L3 TPA/VB and L4 TPA/VB and frailty assessed with the STFI predicted 1-year postoperative mortality on univariate analysis but not major perioperative AEs, LOS or reoperation. Further investigation with a larger cohort is needed to identify the optimal measure for assessing frailty and sarcopenia in this spine population

To identify the presence of the Adamkiewica artery before operating spine tumor patients and avoid neurological complications as well as evaluate the impact on surgical strategy. All tumor patients requiring spinal fixation from Feb 2002 to March 2006 were prospectively enrolled in the study. Included patients either had a primary spine tumor or a spine metastasis. Patients underwent a selective arteriography of the level above, the level below and the level involved by the tumor in order to document any Adamkiewicz artery (AKA). Eighteen patients were enrolled. Six had a primary tumor and twelve had a metastasis between levels T1 to L3. There were no complications related to the radiological procedure. For ten (55%) of patients, the AKA was identified during the selective arteriogram. In seven of the twelve (58%) metastatic cases the AKA was found adjacent to the involved level. In 60% of cases the AKA was found on the left side. In all cases where the AKA was found, the surgical strategy was modified in order to preserve the AKA. No patients had permanent neurological complications. The location of the AKA is extremely variable. in more than half our cases, the AKA was found immediately adjacent to the involved level. This could suggest a vascular explanation for the location of tumors in the spine. The vicinity of the AKA to the tumor site may explain why neurological complications are frequent when operating such spine cases

Aims. The follow-up interval of a study represents an important aspect that is frequently mentioned in the title of the manuscript. Authors arbitrarily define whether the follow-up of their study is short-, mid-, or long-term. There is no clear consensus in that regard and definitions show a large range of variation. It was therefore the aim of this study to systematically identify clinical research published in high-impact orthopaedic journals in the last five years and extract follow-up information to deduce corresponding evidence-based definitions of short-, mid-, and long-term follow-up. Methods. A systematic literature search was performed to identify papers published in the six highest ranked orthopaedic journals during the years 2015 to 2019. Follow-up intervals were analyzed. Each article was assigned to a corresponding subspecialty field: sports traumatology, knee arthroplasty and reconstruction, hip-preserving surgery, hip arthroplasty, shoulder and elbow arthroplasty, hand and wrist, foot and ankle, paediatric orthopaedics, orthopaedic trauma, spine, and tumour. Mean follow-up data were tabulated for the corresponding subspecialty fields. Comparison between means was conducted using analysis of variance. Results. Of 16,161 published articles, 590 met the inclusion criteria. Of these, 321 were of level IV evidence, 176 level III, 53 level II, and 40 level I. Considering all included articles, a long-term study published in the included high impact journals had a mean follow-up of 151.6 months, a mid-term study of 63.5 months, and a short-term study of 30.0 months. Conclusion. The results of this study provide evidence-based definitions for orthopaedic follow-up intervals that should provide a citable standard for the planning of clinical studies. A minimum mean follow-up of a short-term study should be 30 months (2.5 years), while a mid-term study should aim for a mean follow-up of 60 months (five years), and a long-term study should aim for a mean of 150 months (12.5 years). Level of Evidence: Level I. Cite this article: Bone Jt Open 2021;2(5):344–350

In case of spine tumors, when en bloc vertebral column resection (VCR) is indicated and feasible, the segmental defect should be reconstructed in order to obtain an immediate stability and stimulate a solid fusion. The aim of this study is to share our experience on patients who underwent spinal tumor en bloc VCR and reconstruction consecutively. En bloc VCR and reconstruction was performed in 138 patients. Oncological and surgical staging were performed for all patients using Enneking and Weinstein-Boriani-Biagini systems accordingly. Following en bloc VCR of one or more vertebral bodies, a 360° reconstruction was made by applying posterior instrumentation and anterior implant insertion. Modular carbon fiber implants were applied in 111 patients, titanium mesh cage implants in 21 patients and titanium expandable cages in 3 patients; very recently in 3 cases we started to use custom made titanium implants. The latter were prepared according to preoperative planning of en bloc VCR based on CT-scan of the patient, using three dimensional printer. The use of modular carbon fiber implant has not leaded to any mechanical complications in the short and long term follow-up. In addition, due to radiolucent nature of this implant and less artifact production on CT and MRI, tumor relapse may be diagnosed and addressed earlier in compare with other implants, which has a paramount importance in these group of patients. We did not observe any implant failure using titanium cages. However, tumor relapse identification may be delayed due to metal artifacts on imaging modalities. Custom- made implants are economically more affordable and may be a good alternative choice for modular carbon fiber implants. The biocompatibility of the titanium make it a good choice for reconstruction of the defect when combined with bone graft allograft or autograft. Custom made cages theoretically can reproduce patients own biomechanics but should be studied with longer follow-up

To evaluate the prevalence of infection after elective spinal surgery, a prospective study of patients was carried out over 10 years to 2002. Demographic details, diagnosis and indications for surgery, duration of surgery, time delay before surgery and concomitant diseases were recorded. The management and outcome of patients who developed infection postoperatively were noted. During the period, 1050 elective cases were done for scoliosis, tuberculous spine, tumours, trauma, biopsy and degenerative disorders. There were four deep and six superficial infections. Deep infections were treated by debridement and implant removal, with good outcomes. Superficial sepsis settled with local therapy. The rate of sepsis following elective spinal surgery was 0.95% and infections responded well to treatment

Introduction. Aneurysmal bone cysts are uncommon benign lesions affecting the spinal column. They mostly occur in the lumbar spine and have a propensity to affect adjacent vertebrae. We describe 14 aneurysmal bone cysts affecting the spinal column from the Scottish Bone Tumour Registry with regard to assess the incidence, demography, biological behaviour and recurrence rate. Materials and Methods. We identified 14 patients with aneurysmal bone cysts affecting the spinal column. Case notes and radiographs were retrospectively reviewed from the Scottish Bone Tumour registry. Results. There were 9 female and 5 male patients. The mean age at presentation was 24.5 years (range, 6 to 62 years). The spinal location consisted of cervical (3), thoracic (4), lumbar (6) and sacral (1). The treatment included curettage without bone grafting (3), excision (7) and surgical removal with biopsy in rest. Selective angiographic embolisation was carried out in one patient with a cervical cyst and percutaneous sclerotherapy was carried out on another with a sacral cyst. There were two recurrences, of which one was treated with radiotherapy and other with repeat curettage with successful final outcome. Conclusions. The incidence of aneurysmal bone cysts was 5.5% in our registry of all the spine tumours. The recurrence occurred in 14% (2 of 14). In addition to surgery, one should be aware of the role of angiographic embolisation and radiotherapy in selected primary and recurrent ABCs

Introduction: During the last years minimal-invasive augmentation techniques of vertebral bodies have been established to stabilize painful height losses. Kyphoplasty was described in osteoporotic fractures for stabilisation and high restoration of the collapsed vertebral body. Kyphoplasty intends to achieve a reduction of kyphosis prior to cementing. Aim: The study was performed to analyze the Kyphoplasty technique in patients with tumour induced back pain due to affected vertebral bodies. Method: 7 Patients with Tumour induced back pain were enrolled. MRI, CT and x-ray were performed to confirm the diagnosis and for staging. All patients have severe and significant back pain. Primary spine tumours were excluded. To evaluate the clinical outcome the Oswestry. Score and McNab Score were used. CT scans after procedure were performed to detect cement extrusion. The follow up examinations 12 weeks after Kyphoplasty were performed by an independent blinded observer. Results: 6 patients complete 12 week follow up. All subjects reported significant subjective improvement on the McNab Score (2 excellent, 3 good,1 moderate outcome.) Oswestry Score showed the same results (74±12 Pts at Baseline and 28±9 at 12 week follow up)

Introduction: There is clear evidence that violating the margins of a sarcoma or other malignancy during surgical resection will risk local recurrence and diminish overall survival. Previous publications have retrospectively demonstrated this oncologically sound approach to spine tumor management to be internally valid. The external validity or limited generalizability has not been assessed. Methods: A prospective cohort study design. Included were all patients who underwent enbloc surgical resection of a primary tumor of the spine between January 1994 and November 2003, at the authors’ institution. Tumors were classified using the Ennking and WBB staging systems. All specimens were submitted to a single experienced musculoskeletal pathologist. Surgery was performed by the authors. Surgical approach, specimen margins, complications, adjuvant therapy, neurological status, local recurrence and survival were prospectively collected. Results: Twenty-six patients (12 males and 14 females) were eligible for the study. Average age was 42 (range 16 to 70). There were 19 malignant tumors and 7 benign. Review by the pathologist revealed that 13 resections were wide, 5 marginal (at dura) and 7 intralesional (2 planned wide, 1 planned marginal). Except in benign lesions intral-esional or marginal margins occurred at dura. There are 20 surviving patients with an average follow up of 41.5 months (range 6 to 111 months), 15 of who had malignant tumors. None of these patients have evidence of local recurrence and one has evidence of systemic disease. The health related quality of life, using the SF-36, shows acceptable morbidity of these procedures (PCS=37.73 ± 11.52, MCS=51.69 ± 9.54). Conclusions: Principles of wide surgical resection, commonly applied in appendicular oncology, can and should be used for the treatment of primary bone tumors of the spine with anticipated acceptable morbidity and satisfactory survival

Introduction: Only 4–13 % of all spine tumours are primary bone tumours. We report on 180 cases of primary malignant bone tumours of the spine from the Scottish Bone Tumour Registry. The aim of the study was to analyse the incidence, demography, pathology and survival patterns of primary malignant bone tumours of the vertebral column. Materials and Methods: All of the data in the Scottish Bone Tumour Registry is compiled prospectively. This report is based on a retrospective review of all the data from 180 cases of primary malignant bone tumours (excluding metastatic lesions). Results: Of 4,301 registry cases 4.1% were primary malignant lesions (n=180). Seventy two percent of all spinal tumours were primary malignant neoplasms. There were 22 cervical, 72 thoracic, 45 lumbar and 41 sacrococcygeal lesions. There was a male preponderance (103 males & 77 females). The mean age at presentation was 54 years (range, 4–86 years). The top two ranked tumours were myeloma (42) and chordoma (41). Ewing’ sarcoma (15), Leukaemik-Lymphomatous lesions (13), conventional osteosarcoma (10) and Paget’s sarcoma (9) followed thereafter. The predominant presenting symptom was pain. Pathological fracture occurred in 7 patients. The operative treatment consisted of curettage (21), excision (51) and resection (9) with supplemented bone grafting (13). Adjuvant chemo (=61) and radiotherapy (=131) was also used in selective cases. Thirty patients were alive with no evidence of disease at a mean 5 year follow-up. Six were alive with persistent primary disease and/or local recurrence and/or metastases at the time of review. Eighty four patients died with persistent primary disease, 30 patients died of metastatic disease, 9 due to local recurrence and 17 of unrelated causes. Conclusions: Only 4.1% of the musculoskeletal tumours were spinal: 40% involved the thoracic spine. Mean age at presentation was 54 years. Myeloma, chordoma, chondrosarcoma and Ewing’ sarcoma were the most common pathologies. Myeloma predominated: osteosarcoma was much less common in our series compared to previous reports. Early diagnoses resulted into improved outcome

Summary. There is emerging evidence of successful application of IOCS and leucocyte depletion filter in removing tumour cells from blood salvaged during various oncological surgeries. Research on the use of IOCS-LDF in MSTS is urgently needed. Introduction. Intra-operative cell salvage (IOCS) can reduce allogeneic blood transfusion requirements in non-tumour related spinal surgery. However, IOCS is deemed contraindicated in metastatic spine tumor surgery (MSTS) due to risk of tumour dissemination. Evidence is emerging from different surgical specialties describing the use of IOCS in cancer surgery. We wanted to investigate if IOCS is really contraindicated in MSTS. We hereby present a systematic literature review to answer the following questions: 1. Has IOCS ever been used in MSTS? 2. Is there any evidence to support the use of IOCS in other oncologic surgeries?. Methods. A systematic review of the English literature was conducted using computer searching of databases: Medline, Embase, the Cochrane Central Register of Controlled Trials for articles published between 1 January 1986 and 31 Dec 2012. Results. Question 1: A comprehensive literature search did not provide any publication describing the use of IOCS in MSTS. The application of IOCS in MSTS has never been described before. Question 2: Our systematic review shows that the use of IOCS has been extensively investigated in patients undergoing surgery for gynaecological, lung, urological, gastrointestinal, and hepatobiliary cancers. The literature review considered 281 abstracts from the initial search. After consideration by consensus, 30 articles were included in the final analysis. We included in our review -prospective, retrospective studies and in vitro studies. The selected articles were then classified according to the surgical specialty: gynaecological, lung, urological, gastrointestinal, and hepatobiliary cancers and type of studies: reinfusion studies, non-reinfusion studies and in vitro studies. 23 Reinfusion studies: Studies where salvaged blood was actually re-infused into patients and analyzed on the basis of clinical outcomes like survival, recurrence, metastasis rates, and transfusion requirements, etc. IOCS has been extensively investigated in several large cohort studies and large case series with considerable follow-up duration across urological, gynaecological, hepatobiliary and gastrointestinal cancers. Patients receiving salvaged blood have been shown to perform as well or better across a variety of clinical outcome measures as mentioned above. 2 in vitro studies and 5 non-reinfusion studies: Studies where salvaged blood was not re-infused into patients but was analyzed for the presence or viability of tumour cells in the processed blood. They consistently demonstrated the utility of LDF in either greatly reducing the number of tumour cells or even completely eradicating tumour cells from blood-tumour admixtures or salvaged blood. This provides the “proof-of-concept” that LDF is able and is effective in removing tumour cells from blood. Discussion/Conclusion. There is strong evidence that LDF can safely remove tumour cells from salvaged blood. IOCS in patients undergoing cancer surgery is not associated with any adverse clinical outcomes. The reluctance of spine surgeons to use IOCS in MSTS appears to be unsupported. There is ample evidence supporting the use of IOCS in oncological surgeries. Research is needed to evaluate the application of IOCS in MSTS

Summary. This is the first ever study to report the successful elimination of malignant cells from salvaged blood obtained during metastatic spine tumour surgery using a leucocyte depletion filter. Introduction. Catastrophic bleeding is a significant problem in metastatic spine tumour surgery (MSTS). However, intaoperative cell salvage (IOCS) has traditionally been contraindicated in tumour surgery because of the theoretical concern of promoting tumour dissemination by re-infusing tumour cells into the circulation. Although IOCS has been extensively investigated in patients undergoing surgery for gynaecological, lung, urological, gastrointestinal, and hepatobiliary cancers, to date, there is no prior report of the use of IOCS in MSTS. We conducted a prospective observational study to evaluate whether LDF can eliminate tumour cells from blood salvaged during MSTS. Patients & Methods. After Institutional Review Board (IRB) approval, 21 consecutive patients with metastatic spinal tumours from a known epithelial primary (defined as originating from breast, prostate, thyroid, renal, colorectal, lung, nasopharyngeal) who were scheduled for MSTS were recruited with informed consent. During surgery, a IOCS device (Dideco, Sorin Group, Italy) was used to collect shed blood from the operative field. Salvaged blood was then passed through a leucocyte depletion filter (RS1VAE, Pall Corporation, UK). 15-ml specimens of blood were taken from each of three consecutive stages: (i) operative field prior to cell saver processing (Stage A); (ii) transfusion bag post-cell saver processing (Stage B); (iii) filtered blood after passage through LDF (Stage C). Cell blocks were prepared by the pathology department using a standardised laboratory protocol. From each cell block, 1 haematoxylin and eosin (H&E) slide, and 3 slides each labelled with one of the following monoclonal mouse cytokeratin antibodies AE1/3, MNF 116 and CAM 5.2 were prepared. The cytokeratin antibodies are highly sensitive and specific markers to identify tumour cells of epithelial origin. These slides were read by one of two consultant pathologists who were provided full access to information on operative notes, but were blinded to the actual stages from which the slides were derived. Results. One case was excluded when the final diagnosis was revised to infection instead of metastatic spine tumour. Of the remaining cases, 7/21 tested positive for tumour cells in Stage A, 2 positive in Stage B. No specimen tested positive for tumour cells in Stage C. In 5 cases, posterior instrumentation without tumour manipulation was performed. Discussion/Conclusion. In this first-ever study of cell saver use in spine tumour surgery, we prove that leucocyte-depletion filters (LDF) can effectively eliminate tumour cells from blood salvaged during MSTS. It is now possible to conduct a clinical trial to evaluate IOCS-LDF use in MSTS. Our results are consistent with published results of similar studies performed on IOCS and LDF use outside the field of orthopaedic surgery. Spinal metastases originate from a myriad of primary cancers across various organ systems. If LDF can remove tumour cells from blood salvaged during surgery for spinal metastasis of different histological origin, then the finding can likely be extrapolated to several other fields of surgery where IOCS and LDF have not yet been attempted such as: neurosurgery, otolaryngology and general musculoskeletal oncology. Our results form a proof-of-concept for a paradigm shift in thinking regarding autotransfusion during spine tumour surgery

Introduction and Aims: This study examined the feasibility and clinical response of treatment with the Cyberknife Stereotactic Radiosurgery system of patients with spine tumors not amenable to other types of treatment. These included patients with metastases recurrent after previous radiation, those resistant to radiation or those requiring extensive surgery for complete resection. Method: Twenty-nine patients with tumors of the spine were treated with hypofractionated (one to four fractions) high dose radiation (CyberKnife), delivered using implanted fiducial markers for precise stereotactic localisaton. Patients had either recurrent spinal metastases (19), radio-resistant metastases (seven) or small lesions requiring extensive resection (three). After four to six fiducials were implanted, the patient was immobilised in a custom-moulded cradle and a CT scan was obtained with up to 300 slices at 1.25mm intervals. Inverse plannning was done to minimise dose to critical structures in close proximity to the tumor mass. Patients were followed-up with clinical pain scores, total pain medication, functional assessment and follow-up CT and/or MRI at three-month intervals to assess response to treatment. Results: The tumors were located in all areas of the spine from C4 to the sacrum, with renal cell carcinoma being the most common diagnosis. The mean tumor volume was 253.4cc, with a range of 0.33 to 678.9 ccs. The maximum radiation dose prescribed to the tumor ranged from 1600cGy to 2500cGy delivered in one to four fractions. The number of fractions was determined by the tumor volume and whether the spinal lesion had been previously treated with radiation. The maximum allowable dose to the adjacent spinal cord was 800cGy and thus for the majority of the tumors prescribed to 2500cGy, 80% of the tumor volume received at least 2000cGy. Patients were treated in an outpatient setting with an average treatment time of 75 minutes. There were no new neurologic deficits or acute radiation toxicity. Patients with lesions in the lumbar spine or sacrum often experienced a brief period of nausea, which was easily controllable with one dose of anti-emetic. Some patients experienced a period of malaise or lethargy with no predictive factors. Pain was markedly improved in all patients with metastatic disease as demonstrated by pain scores, decreased use of narcotic medications and improved function. Repeat radiographic studies at three months generally demonstrated stable tumor volume, while those at six months showed decrease in tumor size. Conclusion: Stereotactic radiosurgery has distinct advantages over external beam for patients with tumors of the spine, including less toxicity, ability to treat recurrences in previously radiated fields, and shorter treatment durations. While GammaKnife for cranial lesions is a widely accepted technique by neurosurgeons, the use of frameless stereotactic radiosurgery with the Cyberknife is new to the armamentarium of orthopaedic surgeons treating spinal tumors

Introduction: Video assisted thoracoscopic surgery (VATS) is associated with good correction ability for spinal deformity and allow the reconstruction of the anterior column of the spine in tumors, deformity and trauma cases. Stand alone and instrumented procedures are possible. VATS has shown to be safe and can reduce the morbidities of traditional open anterior surgery but is a technically demanding procedure with a steep learning curve. The potential technique-related complication rate is low in experienced hands. Material and Methods: From 2006 till today, 22 thoracic vertebral fractures have been treated with thoracoscopic approach. The mean patients age was 32 years (24–58) and the levels treated between T6 and L1. Five fractures required only anterior approach, with corpectomy, implantation of an expandable cage (Obelisk, Ulrich, Germany) with autologous bone graft and an anterior Macs TL plate (Aesculap, Germany). The others seventeen fractures were treated by combined anterior – posterior approach in the same operating session or, the second, previously performed immediately after the admission. The endoscopic splitting of the diaphragm was performed in 9 cases to expose the L1/L2 levels. Seven patients received decompressive laminectomy during the first posterior approach performed in emergency settings. Endoscopic anterior decompression was required in 5 cases. One thoracic drainage was inserted and removed on third day in most cases. Results: The thoracoscopic approach allowed a reduction of blood loss, better pulmonary function, an earlier mobilization of the patients and a shorter hospital stay. With the experience the duration of surgical time decreased of one third. The mean duration of the procedure was 190 minutes and the blood loss of 220 ml. There were no major complications. In the first group of 8 cases a delayed removal of the thoracic drain and three conversion in open thoracotomy occurred. The patients were radiologically evaluated for bony fusion, sagittal alignement and by VAS and Oswestry scale for the overall satisfaction about the treatment. The mean follow-up time was 10 months (4–32). We didn’t found any loss of correction more than 5 degree. Conclusion: VATS permits a better visualization of the anatomic structures and allows the same reconstruction capabilities of the open technique with a faster recovery, a shorter hospitalization and a better cosmetic results. We observed a significant reduction in postoperative pain and drugs delivered for it. The clinical results have been encouraging. We believe that this technique can be a valuable tool in the management of the thoracolumbar fractures with acceptable morbidity and a little impact of pulmonary function. A careful selection of the patients scheduled for anterior stand alone procedure is required to avoid the risk of failure of the instrumentation

Spinal metastatic disease can result in burst fracture and neurologic compromise. This study aims to examine the effects of tumour location, shape and surface texture on burst fracture risk in the metastatic spine using a parametric poroelastic finite element model. Tumours were found to be most hazardous in the posterior region of the vertebral body, whereas the multiple tumour scenarios reduced risk. Tumour shape may affect the mechanism of burst fracture. Serrated and smooth outer tumour surfaces yielded similar trends. These results can be used to improve guidelines for burst fracture risk assessment in patients with spinal metastases. This study aims to examine the effects of tumour location, shape and surface texture on burst fracture risk in the metastatic spine. Both tumour location and shape are important factors in assessing the risk of burst fracture in the meta-static spine. Improving risk prediction may reduce burst fracture in patients with spinal metastases. Vertebral bulge increased over 30% when the tumour was moved posteriorly. Conversely, for the multi-tumour scenarios, vertebral bulge and axial displacement decreased by 41% and 35% in comparison to a single central tumour. Anterior and lateral movement demonstrated only small effects. Vertebral bulge increased proportionally to mediolateral tumour length and axial displacement increased proportionally to superior-inferior tumour length. Similar trends were seen with smoothed and serrated tumour surfaces. Using a parametric poroelastic finite element model of a metastaticaly involved T7 spinal motion segment, fourteen single and two multi-tumour scenarios were analyzed, each comprising approximately 24% tumour volume. Ellispoidal tumours were positioned in central, anterior, posterior and lateral locations. Tumour shape was altered by adjusting tumour radii for a centrally located tumour. Tumours were modeled using smoothed and serrated outer surface configurations. Burst fracture risk was assessed by measuring maximum vertebral bulge and axial displacement under load. Tumours were found to be most hazardous in the posterior region of the vertebral body, whereas the multi-tumour scenarios reduced risk. Modeling of tumour surface texture did not impact shape or location effects. Tumour shape may affect the mechanism of burst fracture. Funding: This study was supported by the National Science and Engineering Research Council

Chordoma is the second most common primary malignant tumor of the spine. These tumors rarely metastasize but are considered malignant and, when present in younger individuals, can be aggressive. In the setting of unresectable primary, recurrent, or metastatic tumors the current armamentarium of adjuvant therapy for this condition is very limited. Recent research, however, has identified potential targets for immunotherapy, including the tumor associate antigens High Molecular Weight Melanoma Associated Antigen (HMW-MAA) and B7H3. The goal of this investigation was to correlate expression of B7H3 and HMW-MAA in chordoma tumors with disease severity and clinical outcome. Tissue MicroArrays (TMA) were constructed using an automated arrayer to include 70 conventional chordoma tumors obtained from archives at our institution. Triplicate cores (0.6 mm in diameter) from each sample were created and two sets of cores were created for each chordoma specimen. One triplicate sample was incubated in a closed humid chamber with a pool of HMW-MAA-specific mAb, while the other was incubated with mAb specific for B7H3. Samples were washed in PBS and incubated with a secondary antibody for one hour. Staining was evaluated independently by two researchers and scored using validated systems. A retrospective chart review was performed for each chordoma specimen to determine demographic data, disease course, disease status at final follow-up and mortality. Clinical outcomes were then correlated to the expression of HMW-MAA and B7H3 within the chordoma lesions. Kaplan-Meier curves and Cox proportional hazard regression analysis were utilized to facilitate comparisons. Chordoma tumors from 70 patients were included in this study. Average age at the time of presentation was 57.4 years (31–88 years). Average follow-up was 5.5 years (3.6 months-21 years). Forty-three patients developed recurrences and 10 had metastatic disease. Twenty-three patients (33%) had died of disease at the time of final follow-up. Ninety-seven percent of chordoma tumors stained positive for B7H3 while 44% stained positive for HMW-MAA. No correlation could be drawn between clinical course, recurrence rate, or mortality and tumor expression of B7H3 and HMW-MAA. Kaplan-Meier analysis did demonstrate a shorter survival time for patients whose tumors stained positive for HMW-MAA compared to those whose tumors were negative for the antigen. The goal of this investigation was to correlate expression of B7H3 and HMW-MAA in chordoma tumorswith disease severity and clinical outcome. Results indicate that expression of HMW-MAA may be predictive of more aggressive disease and shorter survival. HMW-MAA and especially B7H3, in light of its near universal expression in the chordoma tumors studied here, may serve as potential targets for adjuvant immunotherapy

Introduction: The skeleton is the most common location for metastases, with life-time prevalences of 15% and 70% during autopsies. The Vienna Bone and Soft Tissue Tumor Registry has been established in 1965 and is collecting data on primary and secondary malignancies of the musculoskeletal apparatus ever since. The objective of this study was to review the epidemiology and survival of patients undergoing spinal stabilization, including an analysis of trends over time. Methods: Data on patients operated on between 1980 and 2007 were available from the Tumor registry. Information on location of metastases, number of metastases within and outside the spine, primary tumor, as well as complications and recurrences after treatment were extracted. Survival after surgery was assessed using the Kaplan-Meier method, adjusting for patient age by Lexis expansion. Furthermore, the dataset was expanded on calendar time to test changes in epidemiology and survival during the observed 28 years. The effect of the abovementioned variables on survival was assessed in a Cox regression model using patient age and calendar time as time frame. Results: Data on 254 patients could be ed. The most common primary diagnoses were hypernephroma (26.4%), breast cancer (19.75), and lung cancer (12.2%), mostly metastasizing to thoracic and lumbosacral spine (40% both). 104 patients (47.9%) had multiple spinal and 41 (16.1%) other osseous non-spinal metastases. 14.6% had complications in the immediate postoperative follow-up, 4.3% suffered from recurrences postoperatively. Average survival after surgery was 0.9 years (95%CI 0.7 to 1.0) with an average patient age of 60.4 years (95%CI 58.8 to 62.0). In the regression model location of metastases (p=0.008), primary malignancy (p< 0.001), and recurrences (p=0.008) were associated with decreases in survival. There was no association between survival time and the decade during which patients were treated (p=0.157). However, there were significantly less complications in patients treated in later decades, demonstrating the patient’s benefit of being referred to a specialized centre (p=0.015). Discussion: For our study, we are able to draw from experience of 28 years with stabilization due to spinal metastases. Analyzing the data from 254 patients we observed that spinal metastases stem from a similar pattern of primary malignancies. The average survival in our cohort was less than a year, with a very narrow confidence interval. While survival was not associated with later periods of follow-up, number of complications was, supporting the recommendation to refer cancer patients to specialized centers with appropriate experience. The external validity of our findings, however, is confined by the source of our patients, which comprises mostly central and eastern European patients, and few cases referred from more remote areas