En-bloc resection of a chordoma in L3 by a combined open posterior and less invasive retroperitoneal approach: technical description and case report.

INTRODUCTION: To fulfill oncological criteria, extensive open anterior and posterior approaches are usually performed in the lumbar spine to obtain an appropriate en-bloc spondylectomy. It is commonly accepted that the price of a tumor-free margin includes such extensive incisions and soft-tissue damage, with consequent relevant blood loss and possible postoperative complications as delayed wound healing. In this article, a case of chordoma in L3 is presented, submitted to an oncologically appropriate en-bloc resection performed by an open posterior approach combined with a mini-retroperitoneal approach. The successful oncologic procedure was combined with a short and uneventful postoperative course. MATERIALS AND METHODS: The authors present the surgical technique and the possible challenges of minimally invasive anterior oncologic surgery as a contribution to a limited literature. RESULTS: Up to date, palliative care of single metastases has been the main setting in which anterior, minimally invasive surgery has been performed in the lumbar spine. The authors explained how, in selected cases, this approach can be performed in combination with an open posterior access for an oncologically appropriate treatment of a primary malignant tumor. CONCLUSION: Anterior, minimally invasive surgery can have a role in selected patients with primary malignant tumors of the lumbar spine. The surgical team should have extensive training both in oncologic and minimally invasive surgery.

Rapidly destructive osteoarthritis of the spine: lessons learned from the first reported case.

BACKGROUND: Rapidly Destructive Osteoarthritis (RDOA) has been described for the hip and shoulder joints and is characterized by a quickly developing bone edema followed by extensive remodeling and joint destruction. Confronted with a similarly evolving case of endplate edema and destruction of the disk space, we offer the first described case of spinal RDOA and illustrate the challenges it presented, along with the strategies we put in place to overcome them. CASE PRESENTATION: We present a case of spinal RDOA that, also due to the delay in the diagnoses, underwent multiple revisions for implant failure with consequent coronal and sagittal imbalance. A 37-years-old, otherwise healthy female presented with atraumatic low back pain: after initial conservative treatment, subsequent imaging showed rapidly progressive endplate erosion and a scoliotic deformity. After surgical treatment, the patient underwent numerous revisions for pseudoarthrosis, coronal and sagittal imbalance and junctional failure despite initially showing a correct alignement after each surgery. As a mechanic overload from insufficient correction of the alignement of the spine was ruled out, we believe that the multiple complications were caused by an impairment in the bone structure and thus, reviewing old imaging, diagnosed the patient with spinal RDOA. In case of spinal RDOA, particular care should be placed in the choice of extent and type of instrumentation in order to prevent re-intervention. CONCLUSION: Spinal RDOA is characterized by a quickly developing edema of the vertebral endplates followed by a destruction of the disk space within months from the first diagnosis. The disease progresses in the involved segment and to the adjacent disks despite surgical therapy. The surgical planning should take the impaired bone structure account and the use of large interbody cages or 4-rod constructs should be considered to obtain a stable construct.

Primary sclerosing epithelioid fibrosarcoma of the spine: a single-institution experience.

AIMS: To present our experience on spinal sclerosing epithelioid fibrosarcoma (SEF) and review the existing literature pertaining to SEF of the spine. METHODS AND RESULTS: Six cases of spinal SEF were reviewed, and a literature search of all primary SEFs of the spine was performed. All tumours occurred in adults (median age, 41 years) and were located all along the spine, the lumbar vertebrae being the most commonly involved. All patients presented with pain that they had experienced for months. The mean tumour size at diagnosis was 52 mm. Five tumours showed a spectrum of microscopic features consistent with pure SEF, and one showed a hybrid morphology with areas of low-grade fibromyxoid sarcoma. All were diffusely and strongly positive for mucin 4. Two cases were initially misdiagnosed as epithelioid haemangioendothelioma and aggressive chondroblastoma. Fluorescence in-situ hybridisation showed rearrangements of either FUS or EWSR1 in four cases. Reverse transcription polymerase chain reaction showed the presence of FUS-CREB3L1 and EWSR1-CREB3L1 fusion transcripts in two cases and one case, respectively. Of five patients with follow-up data available, two developed one or more local recurrences and three patients had metastatic disease. Distant metastases were mainly to other osseous locations, followed by lungs and lymph nodes. At last follow-up, three patients had died of disease and one was alive with multiple metastases. CONCLUSIONS: SEF is an aggressive sarcoma that can involve the spine. It is important to recognise the spine as the primary location of SEF, in order to avoid misdiagnosis as more common primary spinal neoplasms, which can impact on therapeutic approaches.

Feasibility of achieving planned surgical margins in primary spine tumor: a PTRON study.

OBJECTIVE: Oncological resection of primary spine tumors is associated with lower recurrence rates. However, even in the most experienced hands, the execution of a meticulously drafted plan sometimes fails. The objectives of this study were to determine how successful surgical teams are at achieving planned surgical margins and how successful surgeons are in intraoperatively assessing tumor margins. The secondary objective was to identify factors associated with successful execution of planned resection. METHODS: The Primary Tumor Research and Outcomes Network (PTRON) is a multicenter international prospective registry for the management of primary tumors of the spine. Using this registry, the authors compared 1) the planned surgical margin and 2) the intraoperative assessment of the margin by the surgeon with the postoperative assessment of the margin by the pathologist. Univariate analysis was used to assess whether factors such as histology, size, location, previous radiotherapy, and revision surgery were associated with successful execution of the planned margins. RESULTS: Three hundred patients were included. The surgical plan was successfully achieved in 224 (74.7%) patients. The surgeon correctly assessed the intraoperative margins, as reported in the final assessment by the pathologist, in 239 (79.7%) patients. On univariate analysis, no factor had a statistically significant influence on successful achievement of planned margins. CONCLUSIONS: In high-volume cancer centers around the world, planned surgical margins can be achieved in approximately 75% of cases. The morbidity of the proposed intervention must be balanced with the expected success rate in order to optimize patient management and surgical decision-making.

Vertebroplasty shows no antitumoral effect on vertebral metastasis: a case-based study on anatomopathological examinations.

PURPOSE: Percutaneous vertebroplasty (VTP) is a well-known surgical technique used for pain management and vertebral consolidation in the treatment of osteolytic metastases of the spine. While this indication is proven and commonly accepted, an antitumoral effect of polymethylmethacrylate (PMMA) has been proposed but not yet demonstrated. The aim of our study is to evaluate the evidences of antitumoral effect on anatomopathological examination. We present a small series of pathology findings after VTP for spine metastases that support the lack of antitumoral effect of PMMA. METHODS: We have retrospectively analyzed three cases of patients treated for en bloc excision of recurrent spine metastases previously submitted elsewhere to VTP on the same levels. We discuss our results with the literature reporting of an antitumoral effect of VTP. RESULTS: In our series, after anatomopathological examination, a cement-induced tumor necrosis was never found. Conversely, a foreign-body reaction around the cement was found, inside vital tumor. These results are consistent with an immune reaction to a foreign body without evidences of an antitumoral effect of PMMA. CONCLUSION: The antitumoral effect of PMMA should not be taken into account as an indication for VTP in spinal metastases. It is important not to misuse VTP as a therapy aiming at tumor control. Other therapies such as radiotherapy, radiosurgery and open surgery are available for that purpose.

Revision surgery for tumors of the thoracic and lumbar spine: causes, prevention, and treatment strategy.

INTRODUCTION: Revision surgery in spine tumor surgery can offer peculiar challenges given the severity of the majority of these lesions and the complexity of surgical procedures that are required. MATERIALS AND METHODS AND RESULTS: Based on literature review and on personal experience, surgical site infection, cerebrospinal fluid leakage, tumor recurrence and hardware failures are some of the possible causes of surgical revision in this set of patients. CONCLUSIONS: The aim of this study is to evaluate the most frequent complications that can lead to revision in spine tumor patients, to provide suggestions on how to prevent these events and to offer reasonable strategies to properly plan and perform a revision surgery. These slides can be retrieved under Electronic Supplementary Material.

Denosumab in the treatment of giant cell tumor of the spine. Preliminary report, review of the literature and protocol proposal.

BACKGROUND: The interest on the role of Denosumab in the treatment strategy of giant cell tumor of the spine is growing. En bloc resection is considered the Enneking appropriate treatment, but morbidity and functional loss are sometimes unacceptable. Denosumab could play a role as a stand-alone treatment, but also as preoperative treatment or as postoperative after intralesional surgery. MATERIALS AND METHODS: A cohort of 10 out of 12 cases of spinal GCT consecutively treated with Denosumab are analyzed and discussed compared to the cases reported in the literature. A staging of the radiological effect of the treatment is proposed. RESULTS: The stand-alone and postoperative treatments are still running (12 to 88 months). One therapy was stopped after 15 months, once a satisfactory local effect was achieved, but the treatment had to be restarted 2 months later due to the recurrence of the erosive images. The new treatment was successful. At 1-year follow-up after the gross total excision followed by postoperative Denosumab treatment, no evidence of local recurrence was found. The preoperative treatment duration ranged from 3 to 24 months. No local recurrence followed the en bloc resections. CONCLUSIONS: Denosumab alone is effective in relieving pain, increasing the ossification and sometimes reducing the tumor volume. It can be considered an excellent solution in spine GCTs whose surgical treatment cannot be Enneking appropriate or is associated with unacceptable morbidity or loss of functions. It is still impossible to state when to safely stop the treatment. Denosumab also plays a role as preoperative protocol. These slides can be retrieved under Electronic Supplementary Material.

Composite PEEK/carbon fiber rods in the treatment for bone tumors of the cervical spine: a case series.

INTRODUCTION: Radiotherapy (RT) is frequently applied as an adjuvant therapy during spinal tumors treatment. Metallic implants can interfere with RT planning and execution, as it is known that metallic implants produce a backscattering effect that can limit RT accuracy and their presence can be associated with unwanted dose increase. PEEK/carbon fiber implants are designed to reduce these problems but their application in the cervical spine is limited, due to the reduced number and types of implants, the screw dimensions and the absence of lateral mass screws. We propose a hybrid system made of carbon rods and screws coupled with subliminal polyester bands with titanium clamps. We designed this hybrid construct to enclose the cervical region in the area of instrumentation without limiting the application of postoperative radiotherapy. MATERIALS AND METHODS: Six patients in which the hybrid hardware was implanted were retrospectively examined. Data on demographics, intraoperative and postoperative events, tumor details and staging and cervical alignment were collected pre- and postoperatively. RESULTS: No intraoperative complications occurred. En bloc resection was performed in two patients, while the remaining four received an intralesional resection. Three out of six patients received postoperative RT, without any alteration in its planning and administration. DISCUSSION AND CONCLUSIONS: Hybrid implants made of composite PEEK/carbon fiber screws and rods and sublaminar bands are a helpful solution for spinal reconstruction in the cervical and cervico-thoracic regions after spine tumor surgery. The implants do not produce artifacts at postoperative images, easing the planning and execution of postoperative radiotherapy.

Patient satisfaction with treatment outcomes after surgery and/or radiotherapy for spinal metastases.

BACKGROUND: Patient satisfaction is infrequently investigated despite its importance in assessing efficacy and patient comprehension. The purpose of this study was to investigate patient satisfaction with treatment outcomes after surgery and/or radiotherapy for spinal metastases and to evaluate how health-related quality of life (HRQOL) is related to patient satisfaction. METHODS: Patients with spinal metastases treated with surgery and/or radiotherapy were enrolled in a prospective, international, observational study. Demographic, histologic, treatment, and HRQOL data were collected. HRQOL was evaluated with the Numeric Rating Scale pain score, the 3-level version of the EuroQol 5-Dimension (EQ-5D-3L) instrument, and the Spine Oncology Study Group Outcomes Questionnaire (SOSGOQ2.0). Patient satisfaction was derived from the SOSGOQ2.0 at 6, 12, and 26 weeks after treatment. Patients were classified as satisfied, neutral, or dissatisfied. RESULTS: Twelve weeks after treatment, 183 of the surgically treated patients (84%) were satisfied, and only 11 (5%) were dissatisfied; in contrast, 101 of the patients treated with radiotherapy alone (77%) were satisfied, and only 7 (5%) were dissatisfied. Significant improvements in pain, physical function, mental health, social function, leg function, and EQ-5D were associated with satisfaction after surgery. Satisfaction after radiotherapy was associated with significant improvements in pain, mental health, and overall SOSGOQ2.0 scores. Dissatisfaction after treatment was associated with lower baseline values for leg strength and lower social functioning scores for surgically treated patients and with lower social functioning scores and being single for patients treated with radiotherapy. CONCLUSIONS: High levels of satisfaction with treatment outcomes are observed after surgery and/or radiotherapy for spinal metastases. Posttreatment satisfaction is associated with significant improvements in pain and different dimensions of HRQOL.

Association of neurologic deficits with surgical outcomes and health-related quality of life after treatment for metastatic epidural spinal cord compression.

BACKGROUND: A critical knowledge gap exists regarding the impact of neurologic deficits on surgical outcomes and health-related quality of life (HRQOL) for patients surgically treated for metastatic epidural spinal cord compression (MESCC). METHODS: This prospective, multicenter and international study analyzed the impact of the neurologic status on functional status, HRQOL, and postoperative survival. The collected data included the patient demographics, overall survival, American Spinal Injury Association (ASIA) impairment scale, Spinal Instability Neoplastic Score, treatment details and complications and HRQOL measures, including version 2 of the 36-Item Short Form Health Survey (SF-36v2) and version 2.0 of the Spine Oncology Study Group Outcomes Questionnaire (SOSGOQ2.0). RESULTS: A total of 239 patients surgically treated for spinal metastases were included. Six weeks after treatment, 99 of the 108 patients with a preoperative ASIA grade of E remained stable, 8 deteriorated to ASIA D, and 1 deteriorated to ASIA A. Of 55 patients with ASIA D, 27 improved to ASIA E, 27 remained stable and 1 deteriorated to ASIA C. Of 11 patients with ASIA A to C, 2 improved to ASIA E, 4 improved to ASIA D, and 5 remained stable. At the 6- and 12-week follow-up, better ASIA scores were associated with better scores on multiple SF-36v2 and SOSGOQ items. Postoperatively, patients with ASIA grades of A to D were more likely to have urinary tract infections and wound complications. Patients with a baseline ASIA grade of E or D survived significantly longer. CONCLUSIONS: Patients with neurologic deficits due to MESCC have worse HRQOL and decreased overall survival. Nevertheless, surgery can result in stabilization or improvement of neurologic function which may translate into better HRQOL. Postoperative care and follow-up are challenging for patients with neurologic deficits because they experience more complications.

Survival, local control, and health-related quality of life in patients with oligometastatic and polymetastatic spinal tumors: A multicenter, international study.

BACKGROUND: The treatment of oligometastatic (≤5 metastases) spinal disease has trended toward ablative therapies, yet to the authors' knowledge little is known regarding the prognosis of patients presenting with oligometastatic spinal disease and the value of this approach. The objective of the current study was to compare the survival and clinical outcomes of patients with cancer with oligometastatic spinal disease with those of patients with polymetastatic (>5 metastases) disease. METHODS: The current study was an international, multicenter, prospective study. Patients who were admitted to a participating spine center with a diagnosis of spinal metastases and who underwent surgical intervention and/or radiotherapy between August 2013 and May 2017 were included. Data collected included demographics, overall survival, local control, and treatment information including surgical, radiotherapy, and systemic therapy details. Health-related quality of life (HRQOL) measures included the EuroQOL 5 dimensions 3-level questionnaire (EQ-5D-3L), the 36-Item Short Form Health Survey (SF-36v2), and the Spine Oncology Study Group Outcomes Questionnaire (SOSGOQ). RESULTS: Of the 393 patients included in the current study, 215 presented with oligometastatic disease and 178 presented with polymetastatic disease. A significant survival advantage of 90.1% versus 77.3% at 3 months and 77.0% versus 65.1% at 6 months from the time of treatment was found for patients presenting with oligometastatic disease compared with those with polymetastatic disease. It is important to note that both groups experienced significant improvements in multiple HRQOL measures at 6 months after treatment, with no differences in these outcome measures noted between the 2 groups. CONCLUSIONS: The treatment of oligometastatic disease appears to offer a significant survival advantage compared with polymetastatic disease, regardless of treatment choice. HRQOL measures were found to improve in both groups, demonstrating a palliative benefit for all treated patients.

Huge myxoid chondrosarcoma expanded into the thoracic cavity with spinal involvement.

PURPOSE: En bloc resection is the treatment of choice of myxoid chondrosarcoma. These tumors can produce huge masses. Anatomical constraints limit the possibility to perform en bloc resection in the spine. METHODS: A very huge myxoid chondrosarcoma (14.2 × 10.8 × 11.4 cm) arising from T2 to T5 and invading the whole higher left pleural cavity was observed. Surgical planning according to WBB staging system was performed. RESULTS: The tumor was successfully submitted to en bloc resection achieving a tumor-free margin as demonstrated by the pathologist's report. CONCLUSIONS: A careful planning and a multidisciplinary collaboration make possible to perform en bloc resection even in apparently impossible cases.

Correction to: Primary vascular bone tumors in the spine: a challenge for pathologists and spine oncology surgeons.

Unfortunately, the affiliation for the following authors was incorrectly published in the original publication.

Primary vascular bone tumors in the spine: a challenge for pathologists and spine oncology surgeons.

PURPOSE: Primary vascular bone tumors of the spine represent a challenge for oncology surgeons, due to the need of planning a surgical strategy appropriate to the tumor behavior. But these tumors represent a challenge also for pathologists, as immunohistochemical and molecular analyses have recently refined the terminology. METHODS: A cohort of 81 cases was retrospectively reviewed, targeting the evolution of diagnoses and the treatment-related outcome. Sixty-six cases (including one case originally diagnosed as chordoma) were diagnosed before 2011, and 15 were diagnosed and treated in the period 2011-2017. Fully documented outcome studies are available for 46 patients whose immunohistochemical and molecular analyses were available. The follow-up ranges from 6 months of the early patient death to 300 months of the longest disease-free survival. RESULTS: The outcome was related not only to the treatment performed, but also to the evolution of diagnoses. The term Hemangioendothelioma that defined a benign aggressive (Enneking stage 3) tumor is now obsolete and replaced by the diagnosis of Epithelioid Hemangioma for benign aggressive tumor and Epithelioid Hemangioendothelioma for low-grade malignant tumor. En bloc resection was appropriate for local control, but 2 out of 7 cases of epithelioid Hemangioendotheliomas died due to the spread of the disease None of the Hemangiomas recurred after intralesional excision with or without radiotherapy, or after vertebroplasty. Both cases of Angiosarcoma had a fast and lethal evolution. CONCLUSIONS: Surgeons must be aware of the evolution of terminology to decide the most appropriate treatment options. These slides can be retrieved from Electronic Supplementary Material.

Psychometric evaluation and adaptation of the Spine Oncology Study Group Outcomes Questionnaire to evaluate health-related quality of life in patients with spinal metastases.

BACKGROUND: The Spine Oncology Study Group Outcomes Questionnaire (SOSGOQ) was developed as the first spine oncology-specific health-related quality of life (HRQOL) measure. This study evaluated the psychometric properties and clinical validity of the SOSGOQ in a diverse cohort of patients with spinal metastases. METHODS: An international, multicenter, prospective observational cohort study including patients with spinal metastases who underwent surgery and/or radiotherapy was conducted by the AOSpine Knowledge Forum Tumor. Demographic, tumor, and treatment data were collected. HRQOL was evaluated using the SOSGOQ and Medical Outcomes Study Questionnaire Short Form 36 Health Survey (SF-36) at baseline and fixed follow-up times. Construct validity was assessed using multitrait scaling analyses, confirmatory factor analyses, and correlation with the SF-36 and NRS pain score. Test-retest reliability was assessed in a subgroup of patients between 12 weeks after treatment and the retest 4 to 9 days later. RESULTS: A total of 238 patients were enrolled at 9 centers across North America; 153 of these patients had HRQOL data available at 12 weeks after treatment. Multitrait scaling analyses and confirmatory factor analyses resulted in a refined version of the SOSGOQ with 4 domains and 4 single items. The revised SOSGOQ (SOSGOQ2.0) demonstrated strong correlations with SF-36 and the ability to discriminate between clinically distinct patient groups. Reliability of the SOSGOQ2.0 was demonstrated to be good, with an intraclass correlation coefficient ranging from 0.58 to 0.92 for the different domains. CONCLUSIONS: The SOSGOQ2.0 is a reliable and valid measure with which to evaluate HRQOL in patients with spinal metastases. It is recommended to use the SOSGOQ2.0 together with a generic HRQOL outcome measure to comprehensively assess HRQOL and increase sensitivity and specificity. Cancer 2018;124:1828-38. © 2018 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Spondylolisthesis and tumors: a treatment algorithm.

BACKGROUND: Pars defect and spondylolisthesis are frequent conditions, while bone tumors-particularly the primaries-are rare. The contemporary occurrence can delay the diagnosis of the tumor, if symptoms are considered related to spondylolisthesis, or can make reconstruction more demanding. To our knowledge, only two case reports of this contemporary occurrence have been published in the literature. Being such rare, guidelines on surgical treatment have not been proposed yet. MATERIALS AND METHODS: A retrospective review of patients treated for spine bone tumors by the senior author from 1990 to 2017 was performed to find cases of contemporary occurrence of spondylolisthesis and/or pars defect and spine bone tumors. General health data, radiological imaging, histological tumor diagnosis, treatment, and follow-up were analyzed and discussed. RESULTS: Among the 1870 patients treated for spinal tumors between 1990 and 2017 by the senior author, 14 cases of association between tumors and spondylolysis/spondylolisthesis were observed. The cohort includes five males (35.7%) and nine females (64.3%), aged 14-72. Mean age of patients at surgery time was 47. CONCLUSIONS: Interactions between spondylolisthesis and bone tumors of the spine are episodic. These two conditions rarely occur in the same patient. No treatment strategy has been described until now. The target of this paper is to propose an algorithm to surgically treat patients with concomitant bone tumor and spondylolisthesis. This classification identifies a treatment-oriented algorithm based on two major categories: type A, bone tumor arising on the same vertebra or to an adjacent level; type B, bone tumor arising at least one unit far from the spondylolisthesis. This algorithm can help the surgeon facing this rare combination of diseases in the appropriate preoperative planning. These slides can be retrieved under Electronic Supplementary Material.

Surgeon's perception of margins in spinal en bloc resection surgeries: how reliable is it?

PURPOSE AND BACKGROUND: En bloc resections aim at surgically removing a tumor in a single, intact piece, fully encased by a continuous shell of healthy tissue-the "margin". Intraoperative continuous assessment of the plane of resection regarding the tumor's margins is paramount. The goal of this study was to evaluate the accuracy of experienced spinal tumor surgeons' perception of these margins. METHODS: A retrospective analysis of a prospectively collected data of 1681 patients affected by spine tumors of whom 217 en bloc resections was performed. Surgeons' intraoperative assessment was compared to the histopathological assessment. RESULTS: Most were primary-163 (42 benign and 121 malignant), metastases occurred in 54 cases. 'Wide' margins were obtained in 126 cases; 'marginal' in 60 cases, and 'intralesional' in 31 cases. Surgeons assessed clear margins in 109 cases and contaminated in 108 cases. When considering marginal margins as a contaminated resection, the surgeon's assessment of clear resection had a sensitivity of 76.89%, specificity of 86.81%, PPV and NPV (positive and negative predictive values) were 88.99 and 73.15%, respectively. Inter-observer agreement was 0.62. When considering marginal margins as a clear resection, the surgeon's assessment of clear resection had a sensitivity of 64.5%, specificity of 100%, PPV and NPV were 100 and 0%, respectively. Inter-observer agreement was 0.29. CONCLUSION: Surgeons are fairly accurate in their intraoperative assessment of clear margins achieved; however, this accuracy is not perfect and exploring ways to improve this intraoperative assessment is of major importance possibly impacting the outcome of the treatment.

Carbon-fiber-reinforced PEEK fixation system in the treatment of spine tumors: a preliminary report.

BACKGROUND: Protocols including combination of surgery and radiotherapy are more and more frequent in the treatment of bone tumors of the spine. In metastatic disease, combination of surgery and radiotherapy is since long time accepted, as based on clinical evidence. In primary tumors, combination of surgery and radiotherapy can be considered in all the cases in which a satisfactory oncological margin cannot be achieved: high-grade malignancies, recurrent tumors, huge tumors expanding in an extracompartimental area, and when tumor-free margin requires unacceptable functional sacrifices. However, metal implants are an obstacle in the collaboration between surgeons and radiation oncologists. Carbon-fiber-reinforced polyethil-ether-ether-ketone (CFR-PEEK) composite implants could make easier and more effective the treatment as radiolucent and not interfering with ionizing radiation and accelerated particles. The purpose of this article is to report the preliminary results from a cohort of patients treated with CFR-PEEK and to evaluate the safety and the non-inferiority of the device respect the commonly used titanium implants. MATERIALS AND METHODS: This study concerns an ambispective cohort series of 34 tumor patients (14 metastases and 20 primaries, most of them recurrent) submitted to thoracic and lumbar spine fixation with a CFR-PEEK composite implants. Oncologic surgery was palliative decompression and fixation in 9 cases, tumor excision in 21, and enbloc resection in 4. Data collected for this preliminary report were all intraoperative remarks, incidence of complications, changes in neurological status, local control, and survival. All the cases were followed 6-36 months (mean 13 months). RESULTS: Only one intraoperative screw breakage occurred out of 232 implanted screws. Pain control and neurological improvement were the early clinical results. Two sacral screws loosening were found at 9 and 12 months in multilevel constructs performed on multirecurrent tumors. Six local recurrences were early found thanks to the implant radiolucency. Radiation oncologists' opinion was favourable as concerning better treatment planning on CT and lacking of scattering effect during the treatment. CONCLUSIONS: No artifacts on imaging studies mean early local recurrence detection. For radiation oncologists, no artifacts on imaging studies mean easier planning and no scattering effect means more effective and safe radiotherapy, particularly when particles are used. Moreover, it seems that the clinical use of CFR-PEEK composite implants may be safe and at least comparable with the commonly used titanium implants in terms of intraoperative complications, stability at weight bearing and at functional recovery. Larger patient series and longer follow-up are required to confirm these data.

Biomimetic 3D-printed custom-made prosthesis for anterior column reconstruction in the thoracolumbar spine: a tailored option following en bloc resection for spinal tumors : Preliminary results on a case-series of 13 patients.

PURPOSE: Various techniques for anterior column reconstruction have been described after en bloc resection of spinal tumors. Limited evidence exists regarding one being superior to another. The purpose of this study is to evaluate 3D-printed vertebral bodies for spinal reconstruction after en bloc resection in the thoracolumbar spine. METHODS: Prospective observational study on custom-made 3D-printed titanium reconstruction of vertebral bodies after en bloc resection for spinal tumor was conducted between November 2015 and June 2017. 3D-printed vertebral bodies were monitored for mechanical complications such as (1) migration, (2) subsidence into the adjacent vertebral bodies, and/or (3) breakage. Complications and related details were recorded. RESULTS: Thirteen patients (7 females and 6 males) were enrolled, and reconstruction of the anterior column was performed using custom-made 3D-printed titanium prosthesis after en bloc resection for spinal tumor (8 primary bone tumors and 5 solitary metastases). Subsidence into the adjacent vertebral bodies occurred in all patients at both proximal and distal bone-implant interfaces; however, it was clinically irrelevant (asymptomatic, and no consequences on posterior instrumentation), in 11 out of 12 patients (92%). In 1 patient (#4), severity of the subsidence led to revision of the construct. At an average 10-month follow-up (range 2-16), 1 implant was removed due to local recurrence of the disease and 1 was revisioned due to progressive distal junctional kyphosis. CONCLUSION: Preliminary results from this series suggest that 3D printing can be effectively used to produce custom-made prosthesis for anterior column reconstruction. These slides can be retrieved under Electronic Supplementary Material.

Fibrocartilaginous mesenchymoma of bone: a single-institution experience with molecular investigations and a review of the literature.

AIMS: Fibrocartilaginous mesenchymoma is a rare intraosseous lesion, with a total of 26 cases described in the literature. This study describes the clinical, radiological and histological features of eight new cases of fibrocartilaginous mesenchymoma collected at a single institution between 1982 and 2016. The presence of GNAS and IDH1/2 mutations and MDM2 amplification was explored to evaluate possible links between fibrocartilaginous mesenchymoma, fibrous dysplasia, de-differentiated chondrosarcoma and low-grade osteosarcoma. METHODS AND RESULTS: Eight new cases of fibrocartilaginous mesenchymoma of bone identified in our archives, dating from 1982 to 2016, were reviewed. The diagnosis was not performed on the initial biopsy in any of these cases, due mainly to the absence of obvious cartilaginous differentiation. On imaging, the tumour contained cartilaginous calcifications and showed a very strong uptake of contrast medium after injection. Histologically, the tumour was characterized by spindle cell proliferation mimicking a low-grade spindle cell sarcoma, associated with epiphyseal growth-plate-like nodules of cartilage and bone production. Molecularly, no GNAS and IDH1/2 mutations or MDM2 amplification were found in the cases analysed. Only one case recurred 1 year following intralesional resection. None died of disease. CONCLUSIONS: This very rare bone tumour has a typical radiological and histological pattern and a favourable survival outcome after treatment. Local recurrences can be prevented with complete surgery. Fibrocartilaginous mesenchymoma does not seem to be related genetically to fibrous dysplasia, low-grade osteosarcoma and de-differentiated chondrosarcoma.