Reconstruction after Pelvic Bone Massive Resection: Evolution and Actuality of 3D-Printing Technology.

PURPOSE OF THE STUDY: Pelvic reconstructions after massive bone resections are among the most challenging practices in orthopedic surgery. Whether the bone gap results after a trauma, a tumor resection, or it is due to a prosthetic revision, it is mandatory to reconstruct pelvic bone continuity and rebuild the functional thread that connects spine and hip joint. Several different approaches have been described in literature through the decades to achieve those goals. MATERIAL AND METHODS: To this date, 3D-printed implants represent one of the most promising surgical technologies in orthopedic oncology and complex reconstructive surgery. We present our experience with 3D-printed custom-made pelvic prostheses to fulfi ll bone gaps resulting from massive bone loss due to tumor resections. We retrospectively evaluated 17 cases treated with pelvic bone reconstruction using 3D-printed prostheses. Cases were evaluated in terms of both oncological and functional outcomes. RESULTS: At the last follow-up, local complications were found in 6 cases (36%): in 4 (23.5%) of them the cause was a local recurrence of the disease, whereas only 2 (12.5%) had non-oncologic issues. The mean MSTS score in our population increased from 8.2 before surgery to 22.3 at the latest clinical control after surgery. DISCUSSION: 3D-printing technology, used to produce cutting jigs and prosthetic implants, can lead to good clinical and functional outcomes. These encouraging results are comparable with the ones obtained with other more frequently used reconstructive approaches and support custom-made implants as a promising reconstructive approach. CONCLUSIONS: Our data confi rm 3D-printing and custom-made implants as promising technologies that could shape the next future of orthopedic oncology and reconstructive surgery. KEY WORDS: custom made prosthesis, pelvic reconstruction, orthopedic oncology, cutting jigs, 3D-printing.

Giant cell tumor of extremities, surgical treatment and local adjuvants: which is the most effective?

Giant cell tumour (GCT) represents 5% of all primitive bone tumours. Standard surgical treatment of GCT includes intralesional excision or segmental resection. Curettage has a higher recurrence rate (10-25% in stage 2 or 3 but does preserve adjacent joint function. The use of local adjuvants such as phenol, alcohol, H2O2, Argon or cement may decrease recurrence rate, yet which local adjuvant works best is still, to this day, controversial. A series of 109 patients with GCT of the extremity, surgical treated in a single Institution from 2016 to 2018, were analysed in a retrospective study. The purpose of our study was to report the incidence of recurrence rate in patients with GCT of limbs treated in a single institution with different local adjuvants. The results of the present study suggests that curettage in association to cryoablation seems to reduce the recurrence rate compared to "classic" local adjuvants.

Total hip replacement: a retrospective multicentric analysis on re-intervention rate after single component revision.

Total hip arthroplasty (THA) revision is a procedure consisting in the replacement of a single or multiple implant components and could take place once or more times (re-revision). The aim of this multicentre study is to evaluate the benefits of single component revision in respect of the principles that define implant stability. Two hundred and forty-two patients underwent THA revision at Orthopaedic Clinic of Pisa and Versilia (ITA) from January 2007 to December 2016. We have systematically excluded revisions due to septic or traumatic prosthesis loosening, revisions of both implant components (cotyle and stem) and replacement alone. To evaluate implant stability, we used preoperative X ray and intra-operative mechanical stress tests, applying accredited criteria. Two hundred and twenty-six patients (93%) underwent a single procedure of THA revision: 193 had cotyle replacement and 33 had femoral stem replacement. The remaining 16 (7 %) underwent at least two procedures: 10 of them had consecutive failure of the same component, while the other 6 had revision of the other component after the first procedure. Considering our cases series, we can assert that single component revision is the best choice when no signs of loosening are present on the remaining component. Nevertheless, an accurate evaluation with unanimous radiological criteria and intraoperative testing is essential for the surgeon to choose the most suitable treatment.

Polymethylmethacrylate-augmented fenestreted pedicle-screw fixation in low bone quality patients: a case series and literature review.

The use of pedicle screws in low bone quality patients implicates risks of secondary implant loosening for grip lack. In fact, the result is a reduced mechanical stability at bone-screw interface and consequently an increased chance of pullout and hardware failure. Augmentation techniques have been described for many years and fenestrated screws that allow cement injection is one of them. This is a retrospective observational study of patients treated at our department with polymethylmethacrylate- (PMMA) augmented fenestrated screws. Indications for posterior instrumentation were traumatic fracture in osteoporotic spine, oncological disease, post-traumatic deformity, degenerative disease, revision surgery and sickle cell disease fractures. Implant stability was evaluated with X-Rays and CT scan performed 3 days after surgery and every 3 months during the follow-up. Accuracy of screw placement was evaluated with Heary classification. Fifty-three surgical treatments in 52 patients were performed and 247 PMMA augmented fenestrated screws were placed. According to the Heary classification, 96.21% resulted Grade I, 1.8% Grade II, 2% Grade IV. A total of 17 complications occurred. Fenestrated screw augmentation should be performed in selected patients in whom the bone quality is insufficient to guarantee implant stability. These screws may result useful in complex cases as revision surgeries, osteoporosis and tumour affections where bone quality is highly compromised.

Cryotherapy efficacy and safety as local therapy in surgical treatment of musculoskeletal tumours. A retrospective case series of 143 patients.

Cryotherapy, also called Cryoablation (CA), is a technique that provides a local treatment to various pathological conditions. In Musculoskeletal tumours management, Cryoablation is well accepted and validated as a treatment in palliative cures for metastatic patients. Recently, CA has been proposed also as an alternative to radiofrequency ablation in osteoid osteoma and other benign tumour treatment with promising results. Cryotherapy with argon ice-balls as local adjuvant in open surgery is a tool that can provide enlargement of surgical margins if used properly. There is still not enough evidence supporting use of cryotherapy as local adjuvant in Musculoskeletal open surgery as the series cited above are very small and there is no comparative RCT between local adjuvant therapies including CA. One-hundred-and-eighty-three patients were treated with Cryoablation from 2000 and 2018 in the Musculoskeletal Tumours Surgery Unit of Careggi (Florence) and the University 2nd Clinic of Pisa. In our study group, 38 patients (26.6%) were affected by bone metastasis, 16 patients (11.1%) by aneurismal bone cysts or angiomas, 22 patients (15.4%) by low-grade malignant musculoskeletal tumours, 2 patients (1,4%) by fibromatosis, 63 patients (44.1%) by benign musculoskeletal tumours (principally Giant Cell Tumours-GCT) and 2 patients (1.4%) by Osteosarcomas. In 125 cases (87.4%), CA has been used as an adjuvant therapy, in 12 cases (8.4%) as a percutaneous ablation therapy and in 6 cases (4.2%) as adjuvant to remove tumoral lesions 'en bloc' or as a 'poor technique' for its sterilizing effect on previously resected bones. Mean follow-up was 10 years. Twenty-three patients (16%) were classified as Alive with Disease (AWD) due to local recurrence or tumour progression (14 metastases, 5 low-grade malignant bone tumours, 4 Giant Cell Tumours). Eight patients died due to the disease (6 metastases, 2 osteosarcomas), while 1 died from leukaemia. One-hundred-and-eleven patients (78%) were classified as Continues Disease Free (CDF). All patients reported decrease in pain-related symptoms after surgery and all surgeons reported better control of blood loss. Three cases (2%) of local skin necrosis or wound dehiscence were reported. No local recurrences were reported after fibromatosis ablation. Our results confirm that CA could be considered as a safe and effective technique to treat various conditions as adjuvant and palliative therapy. In particular, in open surgery, cryotherapy as an adjuvant treatment could lead to very low rates of recurrence in locally aggressive tumours like Giant Cell Tumours. These results could be generalized but a better understanding about indications and outcomes can be reached studying CA in specific populations with comparation to other adjuvant techniques.

Best practices for the management of local-regional recurrent chordoma: a position paper by the Chordoma Global Consensus Group.

Chordomas are rare, malignant bone tumors of the skull-base and axial skeleton. Until recently, there was no consensus among experts regarding appropriate clinical management of chordoma, resulting in inconsistent care and suboptimal outcomes for many patients. To address this shortcoming, the European Society of Medical Oncology (ESMO) and the Chordoma Foundation, the global chordoma patient advocacy group, convened a multi-disciplinary group of chordoma specialists to define by consensus evidence-based best practices for the optimal approach to chordoma. In January 2015, the first recommendations of this group were published, covering the management of primary and metastatic chordomas. Additional evidence and further discussion were needed to develop recommendations about the management of local-regional failures. Thus, ESMO and CF convened a second consensus group meeting in November 2015 to address the treatment of locally relapsed chordoma. This meeting involved over 60 specialists from Europe, the United States and Japan with expertise in treatment of patients with chordoma. The consensus achieved during that meeting is the subject of the present publication and complements the recommendations of the first position paper.

Use of autologous bone marrow cells concentrate enriched with platelet-fibrin on extensor mechanism allograft reconstruction for extensor mechanism failure following total knee arthroplasty.

Allografts techniques remain the best reconstructive strategy for chronic extensor mechanism lesions after total knee arthroplasty (3) but outcomes depend strictly on the host tissue-allograft junctions healing. The purpose of this study is to evaluate if modern techniques of adding autologous bone marrow cells concentrate enriched with platelet-rich fibrin, provide better healing of the allograft. We present the case of an 86 years old patient affected by patellar tendon rupture after TKA. A whole extensor mechanism allograft was performed adding a bone marrow cells concentrate enriched with platelet-rich fibrin on the host tissue-allograft junctions. Preoperatively and at each follow-up the value of Knee Society Score and radiographic consolidation signs were recorded. Radiographic controls showed clear signs of consolidation already at 1 months follow-up and a solid fusion at 3 months. This case report describes a valid method to improve healing using a tissue-construct engineered with stem cells and growth factors.

Complications and survival of megaprostheses after resection of bone metastases.

Treatment of bone metastases is often palliative, aiming at pain control and stabilization or prevention of pathological fractures. However, a complete resection with healing purposes can be performed in selected cases. The aim of our work was to evaluate the survival of megaprostheses used for reconstruction after bone metastases. Between January 2001 and March 2015, we implanted 169 Megasystem-C® (Waldemar LINK® GmbH & Co. KG, Hamburg, Germany) after bone metastasis resection. Patients, 95 females and 74 males, were operated at an average age of 61 (12-87) years for proximal femoral resection in 135 (79.9%) cases, distal femur in 24 (14.2%), proximal tibia in 6 (3.6%), total femur in 3 (1.8%) and intercalary femur in 1 (0.6%). Mostly, breast cancer metastases (30.8%), kidney (17.8%) and lung (14.2%) were treated. At an average follow-up of 21 (1-150) months, we found a 99.4% overall limb salvage and a 96.1% overall survival rate at 1 year, 92.8% at 2 years, and 86.8% at 5 and 10 years. We found 9 (5.3%) mobilization cases of the proximal femoral implant, 3 needed surgical reduction; 2 (1.2%) cases of aseptic loosening of the prosthetic stem; 2 (1.2%) periprotetic infection cases, one requiring a 2-stage revision. Few literature studies have evaluated the survival of megaprosthetic implant in the treatment of bone metastases. Our data show how in this specific context the rate of complications is significantly lower than expected in general orthopedic orthopedic surgery. The use of modular prostheses is a valid reconstructive strategy after bone metastasis resection in selected patients. The rate of short-term complications is exceptionally low; further studies will have to confirm this in the longer term.

Human Preosteoblastic Cell Culture from a Patient with Severe Tumoral Calcinosis-Hyperphosphatemia Due to a New GALNT3 Gene Mutation: Study of In Vitro Mineralization.

Human disorders of phosphate (Pi) handling and skeletal mineralization represent a group of rare bone diseases. One of these disease is tumoral calcinosis (TC). In this study, we present the case of a patient with TC with a new GALNT3 gene mutation. We also performed functional studies using an in vitro cellular model. Genomic DNA was extracted from peripheral blood collected from a teenage Caucasian girl affected by TC, and from her parents. A higher capability to form mineralization nodules in vitro was found in human preosteoblastic cells of mutant when compared to wild-type controls. We found a novel homozygous inactivating splice site mutation in intron I (c.516-2a>g). A higher capability to form mineralization nodules in vitro was found in the mutant cells in human preosteoblastic cells when compared to wild-type controls. Understanding the functional significance and molecular physiology of this novel mutation will help to define the role of FGF23 in the control of Pi homeostasis in normal and in pathological conditions.

OSTEOARTICULAR ALLOGRAFTS IN PAEDIATRIC BONE TUMOR RECONSTRUCTION OF THE KNEE.

Osteoarticular allografts represent a reconstructive option after bone tumor resection around the knee in growing children. The major advantage is the chance to preserve the growth plate of the remaining bone, but the disadvantage is the high failure rate eventually requiring definitive prosthetic replacement at skeletal maturity. We retrospectively reviewed 22 patients who underwent osteoarticular allograft reconstructions of the distal femur (16) or proximal tibia (6). There were 12 females and 10 males with an average age at surgery of 11 years (7-15). The diagnosis was osteosarcoma in 19 cases and Ewing sarcoma in 3. All patients underwent pre- and post-operative chemotherapy. At an average follow-up of 103 months (12-167), 18 patients (82%) were alive and 4 had died (18%). We observed 10 allograft failures requiring prosthetic replacement, 6 in distal femur and 4 in proximal tibia reconstructions. At last follow-up 8 allografts (36%) were still in place. Overall allograft survival was 79.6% at five and 45.8% at ten years. In distal femur, allograft survival was 86.2% at five and 59.1% at ten years. In proximal tibia, allograft survival was 62.5% at 5 years and 31.2% at 67 months. Average limb shortening was 3 cm (0- 5) in 8 patients with the allograft still in situ and 2 cm (0-4) in 10 patients after prosthetic replacement. Average MSTS functional score of the whole series was 25 (83.7%). The MSTS score of patients after revision with prosthetic replacement was 24 (80%) while patients who still had the allograft retained had an average MSTS scores of 26.8 (89.3%). In conclusion, osteoarticular allograft reconstruction of the knee after bone tumor resection in pediatric age can be considered a temporary solution with the aim to limit limb length discrepancy before definitive prosthetic replacement after skeletal maturity.

Clinical and radiographical outcome after surgical treatment of periprosthetic type B proximal femur fractures: a retrospective study.

PURPOSE: Periprosthetic fractures after hip prosthesis represent a constantly increasing clinical problem and a challenging complication to treat surgically. Among these, type B proximal femur fractures should be diagnosed correctly to be treated surgically. The aim of this study was to re-evaluate the type of surgical treatment of periprosthetic fractures. METHODS: We examined the cases treated between January 2012 and February 2018, classifying them according to the U.C.S. AO/OTA. We evaluated the radiographic outcome according to the Beals and Tower criteria. Patients still alive were also re-evaluated according to the H.H.S. and the WOMAC score. RESULTS: We treated 48 patients (12 men, 35 women, average age 81 years), divided into 24 type B1, 14 type B2 and 10 type B3 fractures. The overall consolidation rate was 95.4%, while the major complication (implant dislocation, pseudoarthrosis and deep infection) rate was 12.5%. Clinically, it was possible to reassess 34 patients with a mean follow-up of 38.4 months, an average HHS of 75.89 and a mean WOMAC score of 79.93. CONCLUSIONS: Periprosthetic type B fractures are difficult to manage and require careful preoperative planning and appropriate intraoperative management. However, the overall clinical and radiographic result was satisfactory, although patients should still be aware of the risk of complications associated with this type of fracture.

Augmented Reality as a Tool to Guide Patient-Specific Templates Placement in Pelvic Resections.

Patient-specific templates (PST) have become a useful tool for guiding osteotomy in complex surgical scenarios such as pelvic resections. The design of the surgical template results in sharper, less jagged resection margins than freehand cuts. However, their correct placement can become difficult in some anatomical regions and cannot be verified during surgery. Conventionally, pelvic resections are performed using Computer Assisted Surgery (CAS), and in recent years Augmented Reality (AR) has been proposed in the literature as an additional tool to support PST placement. This work presents an AR task to simplify and improve the accuracy of the positioning of the template by displaying virtual content. The focus of the work is the creation of the virtual guides displayed during the AR task. The system was validated on a patient-specific phantom designed to provide a realistic setup. Encouraging results have been achieved. The use of the AR simplifies the surgical task and optimizes the correct positioning of the cutting template: an average error of 2.19 mm has been obtained, lower than obtained with state-of-the-art solutions. In addition, supporting PST placement through AR guidance is less time-consuming than the standard procedure that solely relies on anatomical landmarks as reference.

Nonmetastatic Ewing family tumors: high-dose chemotherapy with stem cell rescue in poor responder patients. Results of the Italian Sarcoma Group/Scandinavian Sarcoma Group III protocol.

BACKGROUND: High-dose chemotherapy (HDT) was added to conventional chemotherapy in Ewing sarcoma family tumor (EFT) patients, poor responders (PRs) to induction chemotherapy in order to improve their survival. PATIENTS AND METHODS: Patients aged ≤40 years with nonmetastatic Ewing sarcoma (ES) received vincristine (V), doxorubicin (A), cyclofosfamide (C), actinomycin (Ac), ifosfamide (I) and etoposide (E) (VACAc-IE regimen) as induction chemotherapy. As maintenance treatment, good responders (GR) received nine cycles of VACAc-IE regimen. PRs received three cycles of VAC-IE, mobilizing cycle with CE and HDT with Busulfan and Melphalan with stem cell support. RESULTS: Three hundred patients [median age 15 years (3-40 years)] entered the study. One patient refused local treatment, 242 (81%) underwent surgery [with radiotherapy (RT) in 80] and 57 (19%) RT alone. No toxic deaths were recorded. Overall GR were 146 (49%). Twenty-eight PR did not receive HDT. At a median follow-up of 64 months (21-116 months), 5-year overall and event-free survival (EFS) were 75% and 69%, respectively. Five-year EFS was 75% for GR, 72% for PR treated with HDT and 33% for PR who did not receive HDT. CONCLUSIONS: High-dose therapy added to the VACA-IE regimen in PR patients is feasible and effective. Selected groups of patients with ES can benefit from HDT.

Scaffolds combined with stem cells and growth factors in healing of pseudotumoral lesions of bone.

Reconstructions of large lesions or defects often require a bone graft or a bone substitute to promote healing. In common practice the reconstruction of a bone defect is dependent on the site and size of the lesion: in long bones intercalary defects may be managed with Ilizarov technique of bone transport and distraction osteogenesis or the use of a free or pedicled vascularized bone graft, or with Masquelet technique. For cavitary defects the available surgical options include autograft, allograft or xenograft or the use of synthetic scaffolds to promote bone regeneration. In order to promote a faster bone healing tissue engineering proposed the application of enriched graft to fill bone defects. The employment of enriched bone graft has been our choice in the last years to fill contained defects following curettage of a pseudotumoral lesion of bone. We report our clinical experience in terms of safety and success of these procedures at a long-term follow up.

Single-use, patient-specific instrumentation technology in knee arthroplasty: a comparative study between standard instrumentation and PSI efficiency system.

Patient-specific instrumentation is a surgical technique that was created to improve the accuracy of implantation, surgical time and workflow in total knee arthroplasty. This study is a single-center, single-surgeon randomized clinical trial. The aim of this work was to evaluate clinical efficacy of PSI versus standard surgical instrumentation in malalignment risk and blood loss reduction. From April 2015 to September 2016, 40 patients for a total of 40 knees were included in the randomization process. Each patient underwent CT scan of the lower limb including hip, knee and ankle joint with the realization of the PSI system and the TKA with Medacta GMK Primary®. Patients were evaluated 1 month after surgery with X-ray and after 2 months with clinical examination and assessment by Knee Society Score (KSS). Blood loss was detected by adding the values calculated in the operative room and the blood loss in the vacuum systems. In the study group, mean value of KSS was 85.2 (IC 95% 81.2-88.5), mean blood loss was 657 ml (IC 95% 580.6-735.4), and mean value of femorotibial angle was 178.8° (IC 95% 178.5-179.3). In the control group, mean value of KSS was 87.2 (IC 95% 85.3-89.4), mean blood loss was 866.5 ml (IC 95% 763.3-972.5), and mean value of femorotibial angle was 178.9°(IC 95% 177.6-180.3). The Student t test detected a significant difference in blood loss between groups (p < 0.05), and no differences were found between KSS. The single-use instrumentation should improve precision, operative time, turnover time, sterilization and maintenance costs and could help to reduce infection risks. Our results confirm only the improvement on reducing blood loss. In our opinion, this technique should be used in selected patients when the surgeon could have some difficulties to perform femoral cuts on coronal plane or when patients need to have a very little blood loss due to other conditions.

Is minimally-invasive spinal surgery a reliable treatment option in symptomatic spinal metastasis?

OBJECTIVE: Up to 70% of patients with cancer are likely to develop spine metastasis. Radiation therapy is the standard of care for painful spinal metastases in absence of unstable or impending fractures. More frequently these patients require open palliative surgery for pain, vertebral collapse and neurological deficits. Minimally Invasive Spine Surgery (MISS) techniques using percutaneous pedicle screw fixation may be considered as an alternative to open surgery in selected cases. MISS techniques are thought to be associated with fewer tissues damages resulting in early pain relief,  they also allow for early mobilization and optimization of function. PATIENTS AND METHODS: From 2011 to 2018, 52 patients affected by spinal metastasis were treated with MISS techniques in Rizzoli Orthopaedic Institute of Bologna and in Cisanello Hospital of Pisa, Italy. All patients underwent percutaneous pedicle screw fixations (PPSF) coupled with mini-decompressions in case it was required by spinal cord compressions. All patients were evaluated pre and post-operatively by Frenkel classification and VAS scores. RESULTS: Mean follow-up time was 19,4 months. Preoperatively, Frankel scores were E in 37 patients, D3 in 6 patients, D2 in 3 cases, D1 in 3 patients, B in one patient and C in two. The Frankel score improved in 10 patients, remained stable in 40 patients and worsened in two patients. Preoperatively, the mean VAS score in 29 patients treated with PPSF procedure with spinal decompression was 7, while postoperatively, it became 5. In 23 patients who underwent only PPSF procedure without spinal decompression mean VAS score was 5, postoperatively it became 3. CONCLUSIONS: In selected cases, MISS surgeries may be considered as a valid alternative to open surgery. Although the efficacy of PPSF has been well documented in trauma or degenerative spine surgery, there is not sufficient literature about MISS techniques in spinal metastasis and further studies are needed to elucidate the most appropriate patient in which this approach could represent the gold standard of treatment.

Surgical Outcome and Oncological Survival of Osteofibrous Dysplasia-Like and Classic Adamantinomas: An International Multicenter Study of 318 Cases.

BACKGROUND: Osteofibrous dysplasia-like adamantinoma (OFD-AD) and classic adamantinoma (AD) are rare, neoplastic diseases with only limited data supporting current treatment protocols. We believe that our retrospective multicenter cohort study is the largest analysis of patients with adamantinoma to date. The primary purpose of this study was to describe the disease characteristics and evaluate the oncological outcomes. The secondary purpose was to identify risk factors for local recurrence after surgical treatment and propose treatment guidelines. METHODS: Three hundred and eighteen confirmed cases of OFD-AD and AD for which primary treatment was carried out between 1985 and 2015 were submitted by 22 tertiary bone tumor centers. Proposed clinical risk factors for local recurrence such as size, type, and margins were analyzed using univariable and multivariate Cox regression analysis. RESULTS: Of the 318 cases, 128 were OFD-AD and 190 were AD. The mean age at diagnosis was 17 years (median, 14.5 years) for OFD-AD and 32 years (median, 28 years) for AD; 53% of the patients were female. The mean tumor size in the OFD-AD and AD groups combined was 7.8 cm, measured histologically. Sixteen percent of the patients sustained a pathological fracture prior to treatment. Local recurrence was recorded in 22% of the OFD-AD cases and 24% of the AD cases. None of the recurrences in the OFD-AD group progressed to AD. Metastatic disease was found in 18% of the AD cases and fatal disease, in 11% of the AD cases. No metastatic or fatal disease was reported in the OFD-AD group. Multivariate Cox regression analysis demonstrated that uncontaminated resection margins (hazard ratio [HR] = 0.164, 95% confidence interval [CI] = 0.092 to 0.290, p < 0.001), pathological fracture (HR = 1.968, 95% CI = 1.076 to 3.600, p = 0.028), and sex (female versus male: HR = 0.535, 95% CI = 0.300 to 0.952, p = 0.033) impacted the risk of local recurrence. CONCLUSIONS: OFD-AD and AD are parts of a disease spectrum but should be regarded as different entities. Our results support reclassification of OFD-AD into the intermediate locally aggressive category, based on the local recurrence rate of 22% and absence of metastases. In our study, metastatic disease was restricted to the AD group (an 18% rate). We advocate wide resection with uncontaminated margins including bone and involved periosteum for both OFD-AD and AD. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

The sacral chordoma margin.

OBJECTIVE: Aim of the manuscript is to discuss how to improve margins in sacral chordoma. BACKGROUND: Chordoma is a rare neoplasm, arising in half cases from the sacrum, with reported local failure in >50% after surgery. METHODS: A multidisciplinary meeting of the "Chordoma Global Consensus Group" was held in Milan in 2017, focusing on challenges in defining and achieving optimal margins in chordoma with respect to surgery, definitive particle radiation therapy (RT) and medical therapies. This review aims to report on the outcome of the consensus meeting and to provide a summary of the most recent evidence in this field. Possible new ways forward, including on-going international clinical studies, are discussed. RESULTS: En-bloc tumor-sacrum resection is the cornerstone of treatment of primary sacral chordoma, aiming to achieve negative microscopic margins. Radical definitive particle therapy seems to offer a similar outcome compared to surgery, although confirmation in comparative trials is lacking; besides there is still a certain degree of technical variability across institutions, corresponding to different fields of treatment and different tumor coverage. To address some of these questions, a prospective, randomized international study comparing surgery versus definitive high-dose RT is ongoing. Available data do not support the routine use of any medical therapy as (neo)adjuvant/cytoreductive treatment. CONCLUSION: Given the significant influence of margins status on local control in patients with primary localized sacral chordoma, the clear definition of adequate margins and a standard local approach across institutions for both surgery and particle RT is vital for improving the management of these patients.

Episodic spontaneous hypothermia potentially triggered by hyperinsulinemia.

Episodic spontaneous hypothermia is an infrequent disorder, the pathogenic mechanisms of which have not been completely clarified, although alterations in the serotoninergic system have been suggested. We report the history of a girl with episodes of dizziness and shivering associated with a body temperature lower than 35 degrees C since the age of 10 months. At the age of 11 years, she was admitted to a local hospital and an oral glucose tolerance test showed high total insulin levels. Hypoglycemia secondary to hyperinsulinemia was suspected, and a low-carbohydrate (simple) diet was proposed without results. Due to the recurrence of the episodes, episodic spontaneous hypothermia triggered by hyperinsulinemia was suspected, and treatment with flunarizine, a drug considered the first line in the treatment of migraine-related disorders, was started with a resulting reduction in the episodes. A new endocrinological evaluation showed decreased insulin secretion. In our patient, the success of the therapy might be due to the well-known effect of calcium antagonists in inhibiting serotonin uptake and thereby regulating serotonin levels after hyperinsulinism. This case suggests hyperinsulinemia as a potential mechanism for episodic spontaneous hypothermia, probably mediated by an interaction between insulin and the serotoninergic system.

[Minimally invasive techniques for treatment of metastatic cancer]. / Minimal-invasive Techniken zur Behandlung metastasierter Karzinome.

Many percutaneous image-guided ablative techniques have been used in the treatment of cancer-related bone metastases. These techniques are rapidly becoming a focus in the palliative and curative treatment of patients with both benign and malignant bone cancer.In this article we will briefly review the principles of radiofrequency ablation and our experience with this technique, including its use in combination with surgery; we will also discuss other minimally invasive techniques such as cryoablation and osteoplasty in the treatment of bone metastases.