Search

Purpose: The aim of this study was to report on mid- to long-term results following large humeral tumoral resection and reconstruction with the induced-membrane technique in skeletally immature patients suffering from primary malignant bone tumours. Methods: A retrospective analysis identified all children who underwent the two stages of a humeral reconstruction using the induced-membrane technique for primary malignant humerus tumours between 2002 and 2020. Functional assessment was conducted by an independent observer using the Musculoskeletal Tumor Society (MSTS) scoring system for the upper limb. Radiological assessment was performed by two independent observers and the healing index was calculated (i.e., months/cm). Results: Eight adolescents (5 osteosarcomas and 3 Ewing sarcoma), with a mean age of 14.2 years (SD = 2.7), were included. The mean length of the bone resection was 17.4 cm (SD = 3.8), and the mean delay of the resection and reconstruction stages was 9.4 months (SD = 4). The mean follow-up was 6.6 years (SD = 4.3). The mean MSTS score was 77.4% and the global average healing index was 1.04 months/cm (SD = 2.2). Four complications (i.e., prominence device, fracture, aseptic pseudarthrosis, radial palsy) and one local recurrence were observed in four patients, requiring four unplanned surgical procedures in three patients. One patient died fourteen years after the initial treatment due to a lung recurrence. Conclusion: The induced-membrane technique is an effective and safe alternative for reconstructing large humeral bone defects after tumour resection in adolescents. Although this is a two-stage technique, it gives good functional results comparable to other strategies found in the literature. Level of evidence: IV. [ABSTRACT FROM AUTHOR]

Introduction: Osteochondroma is a benign tumor of bone. Malignant transformation of Osteochondroma is the most devastating complication one can encounter. Osteochondroma can transform into any malignancy like Osteosarcoma, Chondrosarcoma and Ewing sarcoma. Malignant transformation is more common in patients with multiple exostosis. Recognition of this malignant transformation is needed to predict the patient's outcome. Case presentation: A 26-year-old male patient came with complaints of a mass in the left knee region for the past 7 years. X-ray of the knee showed multiple pedunculated exostosis on either side of the distal end of the femur, tibia and fibula. Histopathological examination revealed a bony lesion with a cartilaginous cap of increased thickness and cellularity. The cartilaginous cap possesses plump chondrocytes showing binucleation-forming nodules with mild atypia. The cartilaginous cap undergoes endochondral ossification, suggesting the possibility of a secondary peripheral atypical cartilaginous tumor from osteochondroma of the tibia. Discussion: Chondrosarcoma is a heterogeneous type of primary bone cartilaginous malignancy with variable clinical outcomes. Malignant transformation of osteochondroma in the appendicular skeleton was named atypical cartilaginous tumor; in the axial skeleton, it is named Grade 1 Chondrosarcoma. Conclusion: Differentiation between osteochondroma and its malignant transformation can be possible if made in a multidisciplinary setting such as clinical history, radiological findings along with histology to confirm the diagnosis.

Management of periacetabular metastatic bone disease (MBD) is challenging, specifically if associated with bone loss or fracture. The aim of this study was to evaluate the complications and outcomes after undergoing peri-acetabular reconstruction using an 'ice-cream cone' pedestal cup endoprostheses for the most severe cases of (impending) pathological acetabular fractures. Fifty cases with severe periacetabular disease were identified. Acetabular defects were classified using the Metastatic Acetabular Classification (MAC). Pre- and post-operative mobility was assessed using the Eastern Cooperative Oncology Group (ECOG) Performance Status. Pain levels were assessed using a verbal rating scale. Surgical complications and patient survival were analysed; the Prognostic Immune Nutritional Index (PINI) was applied retrospectively to survival. There were 32 females and 18 males with a median age of 65 (41–88). Median post-operative follow-up was 16 months (IQR 5.5–28.5 months). Thirty-nine had complete, and 11, impending pathological fractures. The observed five-year survival was 19%, with a median survival of 16 months (IQR 5.8–42.5 months). Significantly worse survival was observed with PINI scores < 3.0 (p = 0.003). Excluding three perioperative deaths, 13 complications occurred in 12 patients: Implant failure in six patients (four aseptic loosening, one dislocation and one infection). At the final follow-up, mobility and pain levels were improved in 85% and 100%, respectively. Reconstruction of significant pelvic MBD with the 'ice-cream cone' reduces pain and improves mobility. Whilst the mortality rate is high, it remains a reasonable option for bed-bound, immobile patients. We advocate the use of an 'ice-cream cone' prosthesis for selected patients balancing the reported risks with the observed benefits. [ABSTRACT FROM AUTHOR]

Bone tumours are frequent in children but most of them are benign. Moreover, the incidence and type of tumours differ from those of adults. As an orthopaedic surgeon, we will likely encounter a bone lesion in a child and we must be able to distinguish if it is a benign lesion or has malignant characteristics and it is necessary to refer it to a centre specialized in tumours. We will discuss the key points we would have to ask in the medical history, look at the physical examination and the radiological characteristics that will allow us to distinguish between a benign and a malignant bone lesion in a child. When there are doubts about the malignancy of a bone lesion or if the diagnosis is not clear, a biopsy should be performed following certain rules in a specialized centre.

Objective: To determine the value of CT-guided bone core biopsy and investigate factors that affect diagnostic yield and biopsy outcome. Materials and methods: The single-centre retrospective analysis included 447 patients who had CT-guided core biopsy with a 13-G needle (Bonopty®) from January 2016 to December 2021. Histological results or ≥ 6 months of clinical and radiological follow-up served as outcome references. A successful biopsy was classified as "diagnostic" when a definitive diagnosis was made and "adequate" when only the malignant or benign nature of the tumour could be determined. Biopsies were "nondiagnostic" when the nature of the lesion could not be determined. The occult lesions were defined as not seen on CT but visible on other modalities. Results: In 275 (62%) females and 172 (38%) males, the overall success rate was 85% (383 biopsies), with 314 (70%) diagnostic biopsies and 69 (15%) adequate biopsies. There was no relationship between biopsy success and the localisation of the lesion, length of biopsy material, or number of biopsy attempts. The lesions' nature had a statistically significant effect on biopsy success with lytic and mixed lesions having the highest success rate. Occult lesions had the lowest success rate. Conclusion: CT-guided bone core biopsy is an effective method in the workup of musculoskeletal diseases with the highest success rate in lytic and mixed lesions. No apparent relationship was found between biopsy success and biopsy length, number of attempts, or localisation of the lesion. [ABSTRACT FROM AUTHOR]

The free vascularised fibular graft represents the mainstay of intercalary bone defect reconstruction after tumour resection. Different reconstruction techniques are described, favouring internal fixation and possibly overlooking potential advantages of external fixation. This series is a description of the technique performed at our institution using an external fixator for the reconstruction of segmental bone defects which enables to maintain limb length and rotational alignment after large segmental bone resection. Data collected were demographic, surgical and histological data, perioperative complications and postoperative data. Eighteen different complications were encountered in seven patients. Mean reoperation rate was 1.3 per patient but no patient required further interventions in order to correct limb length or rotational alignment. Pin-track infection rate was 6%. The limb salvage rate was 100%. Solid final bone healing was obtained in all patients. External fixation for the reconstruction of intercalary bone defects after tumour resection is a safe technique which might offer the advantage of limb length and alignment preservation. [ABSTRACT FROM AUTHOR]

Osteosarcomas are rare and highly malignant bone tumours which are composed of malignant mesenchymal cells producing osteoid or immature bone. Maxillary osteosarcomas are rare tumours accounting for less than 1% of head and neck malignancies. Aggressive surgical resection is the main modality of treatment with good reconstruction. Due to the complex anatomy and location of maxilla as well as its proximity to the skull, resection with negative margins is always a challenge and so is the reconstruction so as to reduce the morbidity of the patient and to also give a good functional and cosmetic outcome. Clinical outcomes can be improved with administration of neoadjuvant or adjuvant chemotherapy in selected cases and radiotherapy in case of positive margins. A 41-year-old male patient presented to the outpatient department with complaints of a bulge over the hard palate for the past 1 year. CT scan showed a 6 × 5 × 4 cm osseous expansile lesion arising from the maxillary bone. Biopsy of the tumour showed features of conventional high-grade osteosarcoma. Plate-preserving maxillectomy with tracheostomy was done followed by reconstruction with a double free flap. On post-operative day 1, the flap showed signs of venous congestion and a new free anterolateral thigh flap was done. Patient was discharged on day 7 with a Ryles tube and a tracheostomy tube in situ. Final histopathological examination showed that the tumour was a high-grade chondroblastic osteosarcoma. After regular post-operative visits in the outpatient department and evaluation with flexible laryngoscopy, patient was started on oral feed by day 10 and decannulated by day 15. He has been on regular follow-up for the past 1 year and shows no signs of recurrence or residual disease on clinical examination as well as imaging. Maxillary osteosarcoma is a rare bone tumour which requires accurate imaging and biopsy for accurate surgical planning. The ideal treatment modality is radical resection with negative margins and appropriate reconstruction. With the advent of microvascular surgery, free flaps form the backbone for reconstruction of such large defects. [ABSTRACT FROM AUTHOR]

Forequarter amputation (interscapulothoracic amputation) includes surgical removal of an upper limb and the shoulder girdle, including the scapula and a portion of the clavicle. We aim to report about our recent experience of having to resort to this mutilating surgery and the clinicopathological variables in that context. The study was done at a cancer centre in Northeast India. It was an ambispective study design, where the patient cohort who underwent FQA was identified retrospectively from the operative register of major surgeries for the time period 1st June 2020 to 31st May 2022 (24 months), and these patients were followed up prospectively from 1st June 2022 to 31st May 2023 (1 year). The study variables were obtained from the electronic medical records (EMR), the physical case files and the hospital-based cancer registry (HBCR). There were 7 patients who underwent forequarter amputation (FQA) during the two years, and in the same period, 15 patients underwent limb salvage surgery for tumours around the shoulder girdle. This translates to a FQA rate of 31.8%. The male:female ratio of the patients was 3:4. The median age of the patients was 32 years (range 19 to 59 years). The histologies included osteosarcoma (2), chondrosarcoma (2), Ewing's sarcoma (2) and hidradenocarcinoma (1). None of these patients had any distant metastatic disease. Four patients had local disease progression on neoadjuvant chemotherapy. Three of the patients had emergency surgery as a life-saving procedure on account of bleeding from their ulcerated tumours. Two patients had disease which was recurrent and unsalvageable due to the encasement of the neurovascular bundle. The median follow-up was 8 months (range 4 to 18 months). Five patients had distant recurrence with pulmonary metastases (100%) and bone secondaries (14.3%) within a range of 3 to 8 months. None of the patients had any local recurrence. Two patients are on follow-up without any evidence of disease (17 and 18 months respectively). Forequarter amputation is the surgical option when tumours around the shoulder girdle are not amenable to limb-sparing procedures by virtue of their disease extent. These cancers are usually aggressive leading to early distant metastasis. [ABSTRACT FROM AUTHOR]

Chondromyxoid fibromas (CMF) are uncommon benign bone tumours, known for their moderate risk of local recurrence, that may manifest through various symptoms such as pain, swelling, tenderness, or be asymptomatic. Diagnosing CMF is challenging and requires a comprehensive, multidisciplinary diagnostic approach because the tumour frequently resembles numerous other bone lesions. This report describes a case of a 66-year-old female patient with a tumour in her right fibula. The initial diagnosis of a neuroma of the right tibial nerve was based on a magnetic resonance imaging scan. The lesion was surgically removed. Preliminarily subsequent histopathological evaluation identified the mass as a parosteal osteosarcoma. However, due to the uncharacteristic presentation of the tumour, further investigation was carried out. Using immunohistochemical and genetic analyses focused on the expression of MDM-2 and RB-1, along with an examination for alterations in the GNAS gene, the mass has been finally and conclusively identified as a chondromyxoid fibroma. This case demonstrates the ambiguity of the CMF presentation, the accurate diagnosis of which may frequently rely on additional diagnostic measures, including histopathology and targeted genetic tests. Furthermore, this report illustrates an atypical diagnostic journey, from an initial neuroma through a low-grade osteosarcoma, to a final benign chondromyxoid fibroma. [ABSTRACT FROM AUTHOR]

[Display omitted] • The composite scaffold composed of n-HA, MXene and g-C 3 N 4 has excellent photothermal and photodynamic properties. • N-HA can enhance the killing effect of mild hyperthermia combined with ROS on bone tumors, and then eliminate tumor quickly. • The scaffold effectively induces osteogenic differentiation of BMSCs and facilitates the formation of new bone. After resection of bone tumour, the risk of cancer recurrence and numerous bone defects continues to threaten the health of patients. To overcome the challenge, we developed a novel multifunctional scaffold material consisting mainly of nano-hydroxyapatite particles (n -HA), MXene nanosheets and g-C 3 N 4 to prevent tumour recurrence and promote bone formation. N -HA has the potential to restrict the growth of osteosarcoma cells, and the combination of MXene and g-C 3 N 4 enables the scaffolds to produce photodynamic and photothermal effects simultaneously under near infrared (NIR) irradiation. Surprisingly, n -HA can further enhance the synergistic anti-tumour function of photodynamic and photothermal, and the scaffolds can eradicate osteosarcoma cells in only 10 min at a mild temperature of 45 ℃. Moreover, the scaffold exhibit exceptional cytocompatibility and possesses the capacity to induce osteogenic differentiation of bone marrow mesenchymal stem cells. Therefore, this multifunctional scaffold can not only inhibits the proliferation of bone tumour cells and rapidly eradicate bone tumour through NIR irradiation, but also enhances osteogenic activity. This promising measure can be used to treat tissue damage after bone tumour resection. [ABSTRACT FROM AUTHOR]

Abstract Background Osteosarcoma is a malignant bone neoplasia that has high welfare consequences for affected dogs. Awareness of breed and canine conformational risk factors for osteosarcoma can assist with earlier diagnosis and improved clinical management. Study of osteosarcoma in dogs also offers translational value for humans. Anonymised clinical data within VetCompass on dogs under primary veterinary care in the UK were searched for osteosarcoma cases. Descriptive statistics reported overall and breed-specific prevalence. Risk factor analysis used multivariable logistic regression modelling. Results From 905,552 study dogs, 331 osteosarcoma cases were confirmed yielding a one-year period prevalence of 0.037% (95% CI: 0.033–0.041). Breeds with the highest annual prevalence were the Scottish Deerhound (3.28%, 95% CI 0.90–8.18), Leonberger (1.48%, 95% CI 0.41- 3.75), Great Dane (0.87%, 95% CI 0.43- 1.55) and Rottweiler (0.84%, 95% CI 0.64–1.07). The median age at diagnosis was 9.64 years (IQR: 7.97–11.41). Following multivariable modelling, 11 breeds showed increased odds of osteosarcoma compared with crossbred dogs. Breeds with the highest odds included Scottish Deerhound (OR 118.40, 95% CI 41.12–340.95), Leonberger (OR 55.79, 95% CI 19.68–158.15), Great Dane (OR 34.24, 95% CI 17.81–65.83) and Rottweiler (OR 26.67, 95% CI 18.57–38.29). Compared with breeds with mesocephalic skull conformation, breeds with dolichocephalic skull conformation (OR 2.72, 95% CI 2.06–3.58) had increased odds while breeds with brachycephalic skull conformation showed reduced odds (OR 0.50, 95% CI 0.32–0.80). Chondrodystrophic breeds had 0.10 times the odds (95% CI 0.06–0.15) compared with non-chondrodystrophic breeds. Increasing adult bodyweight was associated with increasing odds of osteosarcoma. Conclusions The current study cements the concept that breed, bodyweight and longer leg or longer skull length are all strong risk factors for osteosarcoma in dogs. With this awareness, veterinarians can update their clinical suspicion and judgement, breeders can select towards lower-risk animals, and researchers can robustly define more useful study populations for fundamental and translational bioscience.

Background and objective: Due to their aggressive nature and poor prognosis, malignant femoral bone tumors present considerable hurdles. Early treatment commencement is essential for enhancing vital and practical outcomes. In this investigation, deep learning algorithms will be used to analyze magnetic resonance imaging (MRI) data to identify bone tumors that are malignant. Methodology: The study cohort included 44 patients, with ages ranging from 17 to 78 (22 women and 22 males). To categorize T1 and T2 weighted MRI data, this paper presents an improved DenseNet network model for the classification of bone tumor MRI, which is named GHA-DenseNet. Based on the original DenseNet model, the attention module is added to solve the problem that the deep convolutional model can reduce the loss of key features when capturing the location and content information of femoral bone tumor tissue due to the limitation of local receptive field. In addition, the sparse connection mode is used to prune the connection mode of the original model, so as to remove unnecessary and retain more useful fast connection mode, and alleviate the overfitting problem caused by small dataset size and image characteristics. In a clinical model designed to anticipate tumor malignancy, the utilization of T1 and T2 classifier output values, in combination with patient-specific clinical information, was a crucial component. Results: The T1 classifier's accuracy during the training phase was 92.88% whereas the T2 classifier's accuracy was 87.03%. Both classifiers demonstrated accuracy of 95.24% throughout the validation phase. During training and validation, the clinical model's accuracy was 82.17% and 81.51%, respectively. The clinical model's receiver operating characteristic (ROC) curve demonstrated its capacity to separate classes. Conclusions: The proposed method does not require manual segmentation of MRI scans because it makes use of pretrained deep learning classifiers. These algorithms have the ability to predict tumor malignancy and shorten the diagnostic and therapeutic turnaround times. Although the procedure only needs a little amount of radiologists' involvement, more testing on a larger patient cohort is required to confirm its efficacy.

Craniofacial osteosarcoma accounts for 10% of osteosarcoma malignancies, typically affecting the 4-5th decade of life, with the maxilla being the second-most common site.We report a 58-year-old male, non-smoker, with a lump of his upper jaw which occasionally bled during mastication. Clinical examination revealed an exophytic mass in the upper left tuberosity of the maxilla and no lymphadenopathy, where initial differential diagnosis was squamous cell carcinoma.Radiological investigations revealed a metabolically active left maxillary lesion with maxillary sinus destruction, representing primary malignancy. Histological analyses initially suggested a fibro-osseous lesion; further immunohistochemistry showed cytokeratin AE1/AE3/CK(MNF.116) positivity with 60% ki67 proliferation index; diagnostic of grade 2–3 osteosarcoma. Management included neoadjuvant chemotherapy prior to total maxillectomy and dental prosthetic rehabilitation.We report a novel case of primary osteosarcoma of the maxilla in an adult. Osteosarcoma is challenging to diagnose and an important differential to consider where the mainstay of treatment is early invention.

Simple Summary: OFC (Osteitis Fibrosa Cystica) and Brown Tumours, skeletal lesions commonly found in chronic kidney disease (CKD) patients, are influenced by various risk factors, such as age, sex, medications affecting calcium metabolism, and vitamin D deficiency. The primary cause is secondary hyperparathyroidism, leading to imbalances in calcium and phosphorus levels and osteoclast activation. Other factors, like RAAS hyperactivity and chronic inflammation, may also contribute to their development. The recently described involvement of KRAS mutations turned Brown Tumours from reactive lesions to potentially neoplastic lesions. To manage these conditions, pharmacologic treatments like bisphosphonates, calcimimetics, vitamin D supplementation, and denosumab can help by reducing hyperparathyroidism, restoring calcium levels, and preventing OFC occurrence. Brown Tumours, being rare, lack sufficient understanding regarding their manifestation and treatment. However, considering their impact on CKD patients' quality of life, it is crucial for nephrologists and medical practitioners working with dialysis patients to be aware of various diagnostic and treatment options. Osteitis fibrosa cystica (OFC) and Brown Tumours are two related but distinct types of bone lesions that result from the overactivity of osteoclasts and are most often associated with chronic kidney disease (CKD). Despite their potential consequences, these conditions are poorly understood because of their rare prevalence and variability in their clinical manifestation. Canonically, OFC and Brown Tumours are caused by secondary hyperparathyroidism in CKD. Recent literature showed that multiple factors, such as hyperactivation of the renin–angiotensin–aldosterone system and chronic inflammation, may also contribute to the occurrence of these diseases through osteoclast activation. Moreover, hotspot KRAS mutations were identified in these lesions, placing them in the spectrum of RAS–MAPK-driven neoplasms, which were until recently thought to be reactive lesions. Some risk factors contributed to the occurrence of OFC and Brown Tumours, such as age, gender, comorbidities, and certain medications. The diagnosis of OFC and Brown Tumours includes clinical symptoms involving chronic bone pain and laboratory findings of hyperparathyroidism. In radiological imaging, the X-ray and Computed tomography (CT) scan could show lytic or multi-lobular cystic alterations. Histologically, both lesions are characterized by clustered osteoclasts in a fibrotic hemorrhagic background. Based on the latest understanding of the mechanism of OFC, this review elaborates on the manifestation, diagnosis, and available therapies that can be leveraged to prevent the occurrence of OFC and Brown Tumours. [ABSTRACT FROM AUTHOR]

Aims: Simple Bone Cysts (SBCs) predominantly occur in long bones and 59% harbour NFATC2 rearrangements. Jaw SBC is rare and was previously referred to as traumatic bone cyst. It can rarely occur in association with cemento‐osseous dysplasia (COD). To determine whether jaw SBCs represent the same entity as SBC of the long bones, or if they have a different molecular signature, we collected 48 jaw SBC cases of 47 patients to assess NFATC2 rearrangement. Methods and results: Out of the 48 cases, 36 could be used for fluorescence in‐situ hybridization (FISH), of which nine (two of which associated with COD) were successful using an NFATC2 split probe. The remaining cases failed to show adequate FISH signals. All nine cases lacked NFATC2 rearrangement and five of these showed no detectable gene fusions using Archer FusionPlex. Conclusion: In our study, NFATC2 rearrangement is absent in solitary jaw SBC (n = 7) and COD‐associated SBC (n = 2). Our findings suggest that SBC presenting in the jaw is molecularly different from SBC in long bones. Future molecular studies may confirm the absence of clonal molecular aberrations in SBC of the jaw which would support a non‐neoplastic, reactive origin. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate work ability, activity limitations and physical activity in adults that had gone through major bone sarcoma resection and reconstruction surgery in hip and knee. Twenty patients, of 72 enrolled, and 20 controls were included in this cross-sectional study. Work Ability Index scores (general [0–10 points], physical and mental [1–5 points]), the Patient Specific Functional Scale (0–10 points), step counts and the International Physical Activity Questionnaire (IPAQ) were assessed. Adjusted and unadjusted general linear models were applied. The patients had a mean age of 43 (range, 20–71) years and were assessed 7 years (range, 2–12) after surgery (proximal femoral n = 9, distal femoral n = 7, proximal tibia n = 4). Compared with controls, patients had lower general work ability (mean difference [95%CI], −1.3 points [−2.1, −0.5]) and work ability in relation to physical demands at work (−1.4 points [−2.0, −0.8]). The patients reported higher severities of activity limitation (−6.7 points [−7.9, −5.4]). There were no between-group differences in step counts or IPAQ-scores. Despite similar levels of physical activity, patients showed poorer work ability and severe activity limitation. Post-operative rehabilitation in patients of the working-age population should include assessments of work ability and activities important to the individual. Adults that have gone through resection and reconstruction surgery following bone sarcoma in lower extremity show clinically relevant reductions in work ability and self-selected activities To tailor post-operative rehabilitation at short and long term, initial assessment and monitoring should include work ability and activities important to the individual patient. [ABSTRACT FROM AUTHOR]

Background: Osteosarcoma is a malignant bone neoplasia that has high welfare consequences for affected dogs. Awareness of breed and canine conformational risk factors for osteosarcoma can assist with earlier diagnosis and improved clinical management. Study of osteosarcoma in dogs also offers translational value for humans. Anonymised clinical data within VetCompass on dogs under primary veterinary care in the UK were searched for osteosarcoma cases. Descriptive statistics reported overall and breed-specific prevalence. Risk factor analysis used multivariable logistic regression modelling. Results: From 905,552 study dogs, 331 osteosarcoma cases were confirmed yielding a one-year period prevalence of 0.037% (95% CI: 0.033–0.041). Breeds with the highest annual prevalence were the Scottish Deerhound (3.28%, 95% CI 0.90–8.18), Leonberger (1.48%, 95% CI 0.41- 3.75), Great Dane (0.87%, 95% CI 0.43- 1.55) and Rottweiler (0.84%, 95% CI 0.64–1.07). The median age at diagnosis was 9.64 years (IQR: 7.97–11.41). Following multivariable modelling, 11 breeds showed increased odds of osteosarcoma compared with crossbred dogs. Breeds with the highest odds included Scottish Deerhound (OR 118.40, 95% CI 41.12–340.95), Leonberger (OR 55.79, 95% CI 19.68–158.15), Great Dane (OR 34.24, 95% CI 17.81–65.83) and Rottweiler (OR 26.67, 95% CI 18.57–38.29). Compared with breeds with mesocephalic skull conformation, breeds with dolichocephalic skull conformation (OR 2.72, 95% CI 2.06–3.58) had increased odds while breeds with brachycephalic skull conformation showed reduced odds (OR 0.50, 95% CI 0.32–0.80). Chondrodystrophic breeds had 0.10 times the odds (95% CI 0.06–0.15) compared with non-chondrodystrophic breeds. Increasing adult bodyweight was associated with increasing odds of osteosarcoma. Conclusions: The current study cements the concept that breed, bodyweight and longer leg or longer skull length are all strong risk factors for osteosarcoma in dogs. With this awareness, veterinarians can update their clinical suspicion and judgement, breeders can select towards lower-risk animals, and researchers can robustly define more useful study populations for fundamental and translational bioscience. Plain English summary: Osteosarcoma describes a serious bone tumour. Affected dogs often show a bony or soft tissue swelling with severe pain. Canine and human osteosarcoma show similar patient characteristics, clinical course and tumour biology that make studies on canine osteosarcoma highly valuable to inform on the human disease. This study aimed to interrogate anonymised veterinary clinical data from the VetCompass Programme to explore whether demographic information on dogs such as breed, bodyweight and body shape could be useful to predict osteosarcoma. VetCompass shares anonymised veterinary clinical records for welfare-focused research. This study explored the records of 905,552 dogs under veterinary care in 2016 to identify all cases of osteosarcoma. Advanced statistical methods were used to evaluate links between demographic factors and the risk of osteosarcoma. From the overall study population of 905,552 dogs, there were 331 osteosarcoma cases identified to show a one-year period prevalence of 0.037%. The breeds with the highest frequency of osteosarcoma were the Scottish Deerhound (3.28%), Leonberger (1.48), Great Dane (0.87%), Rottweiler (0.84%) and Greyhound (0.62%). Eleven breeds showed increased risk of osteosarcoma compared with crossbred dogs. Breeds with the highest risk included Scottish Deerhound (× 118.40 times risk), Leonberger (× 55.79), Great Dane (× 34.24) and Rottweiler (× 26.67). Aging was progressively and strongly associated with increasing risk of osteosarcoma. Dogs weighing heavier that the average for their breed had 1.65 times the risk than animals weighing below the breed average. Insured dogs had 1.71 times the risk of being diagnosed with osteosarcoma compared with uninsured dogs which may indicate higher levels of healthcare given to insured dogs compared to uninsured dogs. Chondrodystrophic (short-legged) breeds had 0.10 times the risk of osteosarcoma compared with non-chondrodystrophic breeds. Compared with breeds with mesocephalic (average length) skull conformation, breeds with dolichocephalic (long) skull conformation (× 2.72) had increased odds of osteosarcoma while breeds with brachycephalic (short) skull conformation showed reduced risk (× 0.50). This study cements the concept that breed, bodyweight and longer leg or longer skull length all predispose to osteosarcoma in dogs. With this awareness, veterinarians can update their clinical suspicion and judgement, breeders can select towards lower-risk animals, and researchers can define more useful study populations for better research. [ABSTRACT FROM AUTHOR]

An 11-year-old spayed female Toy Poodle presented with acute tetraparesis. A small subcutaneous mass was found in the right trunk region, and the magnetic resonance revealed a compressive spinal cord lesion due to an irregular bone proliferation at the third cervical vertebra. After surgical resection of the vertebral lesion, the neurological symptoms improved, and the patient could walk on her own. The excised vertebral and subcutaneous masses were diagnosed as a mammary adenocarcinoma on the histopathological examination, with Ki-67 and HER-2 immunohistochemistry staining. This case report highlights the importance of defining the primary tumours of metastatic vertebral tumours and the necessity of palliative surgery to improve the patient's quality of life.

AimsThe proximal tibia (PT) is the anatomical site most frequently affected by primary bone tumours after the distal femur. Reconstruction of the PT remains challenging because of the poor soft-tissue cover and the need to reconstruct the extensor mechanism. Reconstructive techniques include implantation of massive endoprosthesis (megaprosthesis), osteoarticular allografts (OAs), or allograft-prosthesis composites (APCs).MethodsThis was a retrospective analysis of clinical data relating to patients who underwent proximal tibial arthroplasty in our regional bone tumour centre from 2010 to 2018.ResultsA total of 76 patients fulfilled the inclusion criteria and were included in the study. Mean age at surgery was 43.2 years (12 to 86 (SD 21)). The mean follow-up period was 60.1 months (5.4 to 353). In total 21 failures were identified, giving an overall failure rate of 27.6%. Prosthesis survival at five years was 75.5%, and at ten years was 59%. At last follow-up, mean knee flexion was 89.8° (SD 36°) with a mean extensor lag of 18.1° (SD 24°). In univariate analysis, factors associated with better survival of the prosthesis were a malignant or metastatic cancer diagnosis (versus benign), with a five- and ten-year survival of 78.9% and 65.7% versus 37.5% (p = 0.045), while in-hospital length of stay longer than nine days was also associated with better prognosis with five- and ten-year survival rates at 84% and 84% versus 60% and 16% (p < 0.001). In multivariate analysis, only in-hospital length of stay was associated with longer survival (hazard ratio (HR) 0.23, 95% confidence interval (CI) 0.08 to 0.66).ConclusionWe have shown that proximal tibial arthroplasty with endoprosthesis is a safe and reliable method for reconstruction in patients treated for orthopaedic oncological conditions. Either modular or custom implants in this series performed well.Cite this article: Bone Jt Open 2022;3(9):733–740.

Bone tumours are a rare and often highly malignant entity. Early clinical diagnosis is the most important step, but the difficulty of detecting and assessing bone malignancies is in its radiological peculiarity and limited experience of non-experts. Since X-ray imaging is the first imaging method of bone tumour diagnostics, the purpose of this study is to develop an artificial intelligence (AI) model to detect and segment the tumorous tissue in a radiograph. We investigated which methods are necessary to cope with limited and heterogeneous data. We collected 531 anonymised radiographs from our musculoskeletal tumour centre. In order to adapt to the complexity of recognizing the malignant tissue and cope with limited data, transfer learning, data augmentation as well as several architectures, some of which were initially designed for medical images, were implemented. Furthermore, dataset size was varied by adding another bone tumour entity. We applied a data split of 72%, 18%, 10% for training, validation and testing, respectively. To provide statistical significance and robustness, we applied a cross-validation and image stratification with respect to tumour pixels present. We achieved an accuracy of 99.72% and an intersection over union of 87.43% for hold-out test data by applying several methods to tackle limited data. Transfer learning and additional data brought the greatest performance increase. In conclusion, our model was able to detect and segment tumorous tissue in radiographs with good performance, although it was trained on a very limited amount of data. Transfer Learning and data augmentation proved to significantly mitigate the issue of limited data samples. However, to accomplish clinical significance, more data has to be acquired in the future. Through minor adjustments, the model could be adapted to other musculoskeletal tumour entities and become a general support tool for orthopaedic surgeons and radiologists.

Giant cell tumour most commonly occuring in epiphysis of the long bone, present and with pain, tenderness and swelling. It is a solitary lesion with restricted movement and tenderness over the lesion. The tendon sheath is where tenosynovial giant cell tumours typically develop. Because of its remarkably peculiar position, we present a case of giant cell tumour (GCT) tenosynovial of bone in the middle phalaynx in a 33-year-old female with complaints of swelling, pain in ring finger of left hand since 2 months which is rarely seen. After clinical, radiological, pathological investigations tenosynovial giant cell tumour was diagnosed. Following fine needle aspiration cytology, histopathology was utilized to confirm the tumour's diagnosis which was later treated as resection of excision of the tumour with allo/autograft reconstruction. Our case report showed no evidence of recurrence in 2 years of follow-up. Hence our case report proves that early and complete resection of the tumour shows evidence of regain of complete range of motion and decrease recurrence rate. [ABSTRACT FROM AUTHOR]

Abstract Purpose Bone healing in femoral reconstructions using intercalary allografts can be compromised in a tumour context. There is also a high revision rate for non-union, infection, and fractures in this context. The advantages and disadvantages of an associated vascularised fibula graft (VFG) are still a matter of debate. Methods In a multicentre study, we retrospectively analysed 46 allograft reconstructions, operated on between 1984 and 2017, of which 18 were associated with a VFG (VFG+) and 28 without (VFG−), with a minimum follow-up of 2 years. We determined the cumulative probability of bone union as well as the mid- and long-term revision risks for both categories by Kaplan-Meier survival analysis and a multivariate Cox model. We also compared the MSTS scores. Results Significant differences in favour of VFG+ reconstruction were observed in the survival analyses for the probability of bone union (log-rank, p = 0.017) and in mid- and long-term revisions (log-rank, p = 0.032). No significant difference was observed for the MSTS, with a mean MSTS of 27.6 in our overall cohort (p = 0.060). The multivariate Cox model confirmed that VFG+ was the main positive factor for bone union, and it identified irradiated allografts as a major risk factor for the occurrence of mid- and long-term revisions. Conclusion Bone union was achieved earlier in both survival and Cox model analyses for the VFG+ group. It also reduced the mid- and long-term revision risk, except when an irradiated allograft was used. In case of a tumour, we thus recommend using VFG+ from a fresh-frozen allograft, as it appears to be a more reliable long-term option.

Introduction: Giant Cell Tumour (GCT) around the knee joint is the most common site for this locally malignant bone tumour and, in advanced stages, requires excision of the tumour mass. Current recommendations promote joint salvage procedures in allograft or mega prosthetic replacement. Patients undergoing this surgery need massive changes in their lifestyle to cope with their activities of daily living. The psychological and social impact following these procedures has not been extensively studied. Aim: To observe the long term functional results as well as the impact on quality of life in patients undergoing endoprosthetic replacements in GCT around the knee with emphasis on any difference in results among the cases operated for distal femoral and proximal tibial GCT. Materials and Methods: This retrospective study was conducted at Dr Ram Manohar Lohia Institute of Medical Sciences, Lucknow from June 2015 to June 2019 with a total sample size of 21 cases. The two groups formed were; one having GCT of distal end femur and the other group with GCT of proximal end tibia. The evaluation was done for outcome measures by Oxford Knee Score (OKS) and Musculo Skeletal Tumour Society score (MSTS) for their functional outcome and Short Form Health Survey (SF-12) for their quality of life effect at two years postoperatively. Students unpaired t-test was performed for intergroup analysis and Analysis of Variance (ANOVA) was done for within the group analysis for subsequent follow-up visits. Data was analysed using Statistical Package for Social Sciences (SPSS) version 21. Results: The mean age of study population was 33.67±8.674 years. The male-female distribution was insignificant (p=0.673), providing us with a homogenous study group. Recurrent GCT was found significantly more commonly in the proximal tibia group than in the distal femur group (p=0.031). Comparison of OKS and MSTS preoperatively, at six months, at one year, and two years showed statistically significant improvement in successive follow-ups in both the distal femur and proximal tibia groups (p

Introduction: Periacetabular reconstruction after resection of primary bone tumour is a very demanding procedure. They are frequently associated with scarce functional results and a high rate of complications. We report a series of patients with periacetabular resections for primary bone tumours and reconstruction with a porous tantalum (PT) acetabular cup (AC). Materials and methods: 27 patients (median age 30 years) were included, being affected by primary bone tumours of the pelvis and treated with peri-acetabular resection and reconstruction with a PT AC. The diagnoses were 13 osteosarcomas, 7 chondrosarcomas and 7 Ewing sarcomas. Function was assessed with the Harris Hip Score and complications were classified according to Zeifang. Results: The median follow-up was 70 months. 1 patient required removal of the PT AC because of implant associated infection 55 months after surgery. There was 1 hip dislocation and no case of aseptic loosening. At final follow-up, the median HHS was 81 points (range 48–92). Conclusions: The used PT AC had good medium-term survival rates and good functional results. This technique is a viable reconstructive option after resections of periacetabular primary bone sarcomas. [ABSTRACT FROM AUTHOR]

Giant cell angioblastoma is a relatively rare vasogenic tumour. To date, studies on its clinical manifestations, imaging characteristics, pathological features, and prognosis are extremely limited and unknown, with only a few cases recorded. In this study, four cases of giant cell angioblastoma confirmed by pathological examination were reported to improve our understanding and deep exploration of the tumour spectrum. All cases in our study were male, including two adults and two boys. The lesions were located in the lower segment of the femur, medial condyle of the femur, knee joint, and popliteal fossa. Regarding the imaging characteristics, two patients with lesions in bone showed bone destruction, while the other two had lesions that invaded soft tissues, showing irregular, abnormal signal shadows and obvious enhancement. Histopathological analysis revealed that the nodular tumour tissue was mainly composed of oval and spindle cells, with varying numbers of osteoclast-like multinucleated giant cells, and the interstitial tissues were often filled with blood vessels of different sizes. The immunophenotype demonstrates that endothelial cells of small vessels in nodules expressed CD31, SMA, and ERG, while osteoclast-like multinucleated giant cells and histiocytes expressed CD68 and CD163, and the surrounding cells expressed SMA. All four patients were treated with surgical resection. One of them relapsed 1 month after surgery and received a second surgical resection. No distant metastasis or death occurred during the follow-up period. This study indicates that giant cell angioblastoma is a local invasive vascular tumour that can develop both in children and adults with skin, mucous membrane, soft tissue, and bone involvement. Imaging characteristics show bone destruction and irregular, abnormal signal shadows; in addition, obvious pathological morphological features can be observed. Currently, the treatment is mainly surgical resection, and interferons may be used as adjuvant chemotherapy.

Introduction: It is often difficult to clinically and radiologically diagnose intra-articular osteoid osteomas and osteoid osteomas of the hip joint. Treatment can also be difficult due to complex locational relationships. CT-guided radiofrequency ablation is currently the standard form of treatment. In this paper we report on a minimally-invasive concept for treating osteoid osteomas near the hip joint in children and adolescents which does not involve using computed tomography. Material and method: 10 patients with an average age of 12.1 years underwent treatment for osteoid osteomas in the hip joint region. The diagnosis was made using a contrast-enhanced MRI. The osteoid osteomas were marked percutaneously using x-ray and MRI guidance. MRI-guided drilling/curettage was performed in 4 cases and arthroscopic resection in 6 cases. Results: All lesions were successfully treated using the MRI-guided method. All patients were free of pain after the treatment. There was no instance of recurrence during the follow-up period, which averaged 10 months. The effective dose for marking the lesion was between 0.0186 mSv and 0.342 mSV (mean 0.084 mSV). Conclusions: Our MRI diagnostics protocol, the MRI-guided drilling and the minimally invasive hip arthroscopy represent an alternative to CT-guided radiofrequency ablation in the treatment of osteoid osteomas. Radiation exposure can thereby be significantly reduced. Hip arthroscopy can also be used to treat secondary pathologies such as femoroacetabular impingement. [ABSTRACT FROM AUTHOR]

Objective: To focus on the imaging features of liposclerosing myxofibrous tumor (LSMFT) and diagnostic challenges to enhance clinical recognition and differential diagnosis accuracy., Methods: Retrospective analysis was conducted on the imaging and pathological data from 21 cases diagnosed with LSMFT between January 2014 and November 2022, including 14 males and 7 females (aged from 21 to 73 years; the course of disease ranged from 4 to 48 months). Patient demographics, clinical presentations, and imaging modalities including X-ray, CT, and MRI were reviewed. Pathological findings were correlated with imaging features to delineate diagnostic criteria and identify causes of misdiagnosis., Results: All 21 patients represented primary lesions, located in 14 bilateral femurs [9 on the right and 5 on the left; 12 proximal femurs (intertrochanteric and peripheral) and 2 distal femurs], 2 proximal tibia, 2 proximal humerus, 1 proximal radius, and 1 ilium and 1 calcaneus. On X-ray and CT, all lesions showed cartographical or quasi-circular osteolytic destruction with distinct and sclerotic margins, continuous bone cortex, absence of periosteal reaction and surrounding soft tissue mass. Calcification, bone ridge and varying degrees of fat components were observed in 16 lesions, displaying mixed density;5 lesions showed ground-glass density with minimal bone ridge. On MRI, the signal intensity of the lesion was heterogeneous. T1-weighted imaging showed iso-to slightly high signal intensity, while T2-weighted imaging demonstrated unevenly high signal intensity. Fat-suppressed sequences depicted significantly elevated signal intensity within lesions, with post-contrast enhancement showing uneven patterns. 5 Cases were initially misdiagnosed as fibrous dysplasia., Conclusion: LSMFT is an uncommon benign bone tumor, typically localized in the proximal femur but occasionally found in other skeletal sites. Understanding its distinct imaging characteristics is crucial for accurate diagnosis. Typical cases exhibit identifiable imaging patterns, whereas atypical presentations may lead to misdiagnosis as fibrous dysplasia.

Cite this article: Bone Joint Res 2023;12(5):311–312.

The proximal tibia is one of the most common locations for primary malignant bone tumours and is usually seen in a population that has not attained skeletal maturity. Most of the surgical techniques for resection and reconstruction of the proximal tibia in children involves sacrificing the distal femoral epiphysis, which leads to a significant limb length discrepancy. Hemiarthroplasty is a relatively lesser known technique for knee joint reconstruction that preserves one of the epiphyses around the knee joint. Pedicle freezing is a sterilization technique used to treat malignant bone tumours, without performing an osteotomy of the diaphysis, thereby preventing non-union which is the most common complication of biological reconstruction techniques. We describe the surgical technique of hemiarthroplasty of the pedicle-frozen proximal tibia for malignant bone tumours of the proximal tibia. This is a novel, safe and effective reconstructive method in children, resulting in reduced limb length discrepancy and excellent functional outcomes. [ABSTRACT FROM AUTHOR]

Purpose: Bone healing in femoral reconstructions using intercalary allografts can be compromised in a tumour context. There is also a high revision rate for non-union, infection, and fractures in this context. The advantages and disadvantages of an associated vascularised fibula graft (VFG) are still a matter of debate. Methods: In a multicentre study, we retrospectively analysed 46 allograft reconstructions, operated on between 1984 and 2017, of which 18 were associated with a VFG (VFG+) and 28 without (VFG−), with a minimum follow-up of 2 years. We determined the cumulative probability of bone union as well as the mid- and long-term revision risks for both categories by Kaplan-Meier survival analysis and a multivariate Cox model. We also compared the MSTS scores. Results: Significant differences in favour of VFG+ reconstruction were observed in the survival analyses for the probability of bone union (log-rank, p = 0.017) and in mid- and long-term revisions (log-rank, p = 0.032). No significant difference was observed for the MSTS, with a mean MSTS of 27.6 in our overall cohort (p = 0.060). The multivariate Cox model confirmed that VFG+ was the main positive factor for bone union, and it identified irradiated allografts as a major risk factor for the occurrence of mid- and long-term revisions. Conclusion: Bone union was achieved earlier in both survival and Cox model analyses for the VFG+ group. It also reduced the mid- and long-term revision risk, except when an irradiated allograft was used. In case of a tumour, we thus recommend using VFG+ from a fresh-frozen allograft, as it appears to be a more reliable long-term option. [ABSTRACT FROM AUTHOR]

Aims: Hydroxyapatite (HA)-coated collars have been shown to reduce aseptic loosening of massive endoprostheses following primary surgery. Limited information exists about their effectiveness in revision surgery. The aim of this study was to radiologically assess osteointegration to HA-coated collars of cemented massive endoprostheses following revision surgery. Methods: Retrospective review of osseointegration frequency, pattern, and timing to a specific HA-coated collar on massive endoprostheses used in revision surgery at our tertiary referral centre between 2010 to 2017 was undertaken. Osseointegration was radiologically classified on cases with a minimum follow-up of six months. Results: In all, 39 patients underwent radiological review at mean 43.5 months; 22/39 (56.4%) showed no osseointegration to the collar. Revision endoprostheses for aseptic loosening were less likely to show osseointegration compared with other indications for revision. Oncological cases with previous or current infection were more likely to show osseointegration to ≥ 1 collar side than those without evidence of prior infection. Conclusion: This seven-year review identified osseointegration of HA-coated collars after revision surgery is less likely (43.6%, 17/39) than after primary surgery. Young patients who undergo revision surgery following initial oncological indication may benefit the most from this collar design. Use in revision oncological cases with a history of infection may be beneficial. HA-coated collars showed limited benefit for patients undergoing revision for failed arthroplasty with history of infection.

Aneurysmal bone cyst is a rare non neoplastic tumour of bones. It is a cystic vascular lesion causing local destruction and invasion of adjacent structures with rapid invasion. Therefore, it requires early intervention. It typically involves long bones of limbs, ribs of thoracic cage, pelvic bones, and vertebrae in axial skeleton. Rarely it occurs in the head and neck region where mandible is found to be the most common site. It has been reported to arise from paranasal sinuses. However, ethmoid sinus is a very rare site. The rarity of aneurysmal bone cyst in such a location, involvement of adjacent structures, and recurrences makes it more interesting for radiologists. Here, the authors present an unusual site of aneurysmal bone cyst in a 22-year-old female involving the right ethmoid sinus with its typical Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) features.

Background: Patient Specific Instruments (PSI) is currently a proven technique for bone tumor resection. In a previous publication, we analyzed the quality of margin resection of pelvic sarcoma resections with the use of PSI (by pathologic evaluation of the margins). In this new study, we compare preoperative resection planning and actual resection margins by MRI analysis of the resection specimens. Methods: Between 2011 and 2020, 31 patients underwent bone tumor resection with the use of PSI. Preoperatively, the margins were planned with a software and PSI were made according to these margins. Postoperatively, the surgical resection specimens were analyzed with MRI. Resection margins were measured with the same software used in the preoperative planning. Results: All margins were safe (free of tumor). The differences between preoperative planned margins and the obtained ones were within the range −5 to +5 mm. The correlation between planned margin and the obtained one was excellent (R2 = 0.841; p

Giant cell tu mour accounts for up to 5% of all bone tumours and malignant giant cell tumour arises in < 10% of cases, representing sarcomatous transformation. Primary malignant giant cell tumour of bone occurs when sarcomatous tissue is observed within conventional giant cell tumour histologically on initial presentation. Secondary malignant giant cell tumour of bone occurs in a region of previously treated giant cell tumour, with most cases arising due to prior radiotherapy. Malignancy in giant cell tumour of bone does not have any unique clinical or imaging features compared to conventional aggressive disease. Historically, malignant giant cell tumour of bone has a poor prognosis which is worse in cases of secondary malignancy. This article aims to present the clinical, pathological and imaging features of MGCTB based on a review of the literature and illustrated by examples from our experience. [ABSTRACT FROM AUTHOR]

Background/Aim Enchondroma is the most common primary bone tumour of the hand. When surgery is indicated, curettage with or without void augmentation has been described. However, only few comparative studies exist. The aim of this study was to compare the outcomes of hand enchondromas treated with autologous bone graft (AG) and bioactive glass S53P4 (BAG). Patients and Methods: A retrospective comparative analysis was conducted among patients surgically treated for hand enchondromas at a tertiary referral centre during a 17-year period. Results: A total of 190 patients (116 AG vs. 74 BAG) with 205 enchondromas were included. No statistically significant differences in outcome measures were observed. A reoperation was performed in five patients in the autologous bone-graft group; one patient presented a rare malignant transformation from enchondroma to chondrosarcoma after the primary operation. No reoperations were performed in the BAG group. Conclusion: Although AG is the gold standard for filling bony cavities, bone-graft retrieval can cause complications and postoperative pain. Our results suggest that S53P4 BAG is a safe and effective bone-graft material alternative for filling of enchondroma-evacuated cavities. [ABSTRACT FROM AUTHOR]

Whole lung irradiation (WLI) has been used successfully in humans as an adjuvant treatment for osteosarcoma. The aim of this study is to describe the feasibility and safety of WLI in dogs with appendicular osteosarcoma. Twelve client‐owned dogs with appendicular osteosarcoma that had successfully completed amputation and four doses of carboplatin without evidence of gross metastasis were enrolled in this prospective clinical trial. Ten once‐daily fractions of 1.75 Gy were administered to the planning target volume encompassing the lungs. Overall, WLI was well tolerated in these patients. No dogs developed symptoms of pneumonitis or pulmonary fibrosis. Haematopoietic toxicity evaluated during radiation therapy was found to be mild. The median disease free interval for WLI treated dogs was not significantly different than the median DFI for a group of historic control dogs (376 days for WLI treated dogs versus 304.5 days for control dogs; p = 0.5461). Although no significant improvement in outcome was observed with this study, WLI appears to be safe in dogs and warrants further investigation to characterize the efficacy and toxicity. [ABSTRACT FROM AUTHOR]

Objectives: To propose a histological-grades-based Osseous Tumor Radiological and Interpretation and Management System (OT-RIMS) that would simplify the radiological evaluation of bone tumours, categorize key radiological features into severity levels, and inform corresponding patient management actions., Methods: This retrospective study between January 2015 and August 2022 evaluated patients with solitary bone tumours confirmed by pathology and imaging follow-up received 2 or 3 imaging modalities of radiographs, CT, or MRI. Three radiologists independently assessed radiological features, categorized bone lesions based on OT-RIMS criteria, and reached a consensus. Kappa statistics and observed agreement were calculated., Results: A total of 341 patients (mean age, 26.0 years; 159 women) were included, with 102 malignant, 177 benign, and 62 intermediate or low-grade malignant bone lesions. Sensitivity and specificity of readers 1, 2, and 3, respectively, in the identification of malignant tumours into OT-RIMS 4 were 93.1% (95 of 102) and 93.3% (223 of 239), 96.1% (98 of 102) and 91.6% (219 of 239), 92.2% (94 of 102) and 89.5% (214 of 239). Inter-reader agreement of OT-RIMS category for 3 readers was considered excellent (Kendall's W = 0.924, P < .001) with a kappa value of reproducibility in categories 1&2, 3, and 4 of 0.764, 0.528, and 0.930, respectively., Conclusions: The OT-RIMS category demonstrated excellent reproducibility despite the reader's expertise level in categorizing the risk stratification of bone tumours and informing patient management, with histological grades used as the reference standard., Advances in Knowledge: The OT-RIMS category reliably stratifies bone tumours into 4 categories corresponding to histological grades and standardized patient management., (© The Author(s) 2024. Published by Oxford University Press on behalf of the British Institute of Radiology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Despite numerous published studies describing adjuvant chemotherapy for canine appendicular osteosarcoma, there is no consensus as to the optimal chemotherapy protocol. The purpose of this study was to determine whether either of two protocols would be associated with longer disease-free interval (DFI) in dogs with appendicular osteosarcoma following amputation. Dogs with histologically confirmed appendicular osteosarcoma that were free of gross metastases and underwent amputation were eligible for enrollment. Dogs were randomized to receive either six doses of carboplatin or three doses each of carboplatin and doxorubicin on an alternating schedule. Fifty dogs were included. Dogs receiving carboplatin alone had a significantly longer DFI (425 versus 135 days) than dogs receiving alternating carboplatin and doxorubicin (P = 0.04). Toxicity was similar between groups. These results suggest that six doses of carboplatin may be associated superior DFI when compared to six total doses of carboplatin and doxorubicin.

Background: Central giant cell granulomas (CGCG) of the jaws are osteolytic lesions that may behave aggressively and respond poorly to surgery. Microscopically, in addition to giant cells, there is a mononuclear cell population composed of macrophage/monocytic cells and spindle‐shaped cells of mesenchymal origin. Seventy two percent of these tumours harbour mutually exclusive TRPV4, KRAS and FGFR1 mutations. We aimed to assess the mutational status of mononuclear and giant cells and the osteogenic potential of stromal cells in vitro and in vivo. Methods and Results: We screened CGCG for signature mutations and used laser‐capture microdissection to demonstrate that the mutations are restricted to the mononuclear cells. Additionally, we established CGCG primary cell culture and observed that the cells retained the mutations throughout passages. By flow cytometry, we observed predominance of CD14−CD51−CD61− cells, consistent with the expected profile for stromal cells. Considering the mesenchymal origin of stromal cells, we assessed the osteogenic differentiation potential of CGCG cells in culture by cytochemistry (von Kossa and alizarin red staining), alkaline phosphatase (ALP) activity assay and gene expression of osteogenic markers. CGCG cells presented self‐capacity to increase ALP levels in a time‐dependent manner and under osteogenic induction presented increasing number of calcium deposits, and overall higher expression of osteocalcin, RUNX2, ALPL and osteopontin than cells without osteogenic induction. A patient‐derived xenograft model for CGCG was established, and osteoid material deposition was observed. Conclusion: Collectively, the results confirm that the signature mutations are restricted to stromal cells in CGCG, and the in vitro and in vivo results support that these cells have the capacity to differentiate into osteoblasts, in line with the bone formation often observed in the stroma of these lesions. [ABSTRACT FROM AUTHOR]

Purpose: Drug screening programmes have revealed epidermal growth factor receptor inhibitors (EGFRis) as promising therapeutics for chordoma, an orphan malignant bone tumour, in the absence of a known genetic driver. Concurrently, the irreversible EGFRi afatinib (Giotrif®) is being evaluated in a multicentric Phase II trial. As tyrosine kinase inhibitor (TKI) monotherapies are invariably followed by resistance, we aimed to evaluate potential therapeutic combinations with EGFRis. Methods: We screened 133 clinically approved anticancer drugs as single agents and in combination with two EGFRis (afatinib and erlotinib) in the clival chordoma cell line UM-Chor1. Synergistic combinations were analysed in a 7 × 7 matrix format. The most promising combination was further explored in clival (UM-Chor1, MUG-CC1) and sacral (MUG-Chor1, U-CH1) chordoma cell lines. Secretomes were analysed for receptor tyrosine kinase ligands (EGF, TGF-α, FGF-2 and VEGF-A) upon drug treatment. Results: Drugs that were active as single agents (n = 45) included TKIs, HDAC and proteasome inhibitors, and cytostatic drugs. Six combinations were analysed in a matrix format: n = 4 resulted in a significantly increased cell killing (crizotinib, dabrafenib, panobinostat and doxorubicin), and n = 2 exhibited no or negligible effects (regorafenib, venetoclax). Clival chordoma cell lines were more responsive to combined EGFR-MET inhibition. EGFR-MET cross-talk (e.g. via TGF-α secretion) likely accounts for the synergistic effects of EGFR-MET inhibition. Conclusion: Our screen revealed promising combinations with EGFRis, such as the ALK/MET-inhibitor crizotinib, the HDAC-inhibitor panobinostat or the topoisomerase-II-inhibitor doxorubicin, which are part of standard chemotherapy regimens for various bone and soft-tissue sarcomas. [ABSTRACT FROM AUTHOR]

Background: Osteosarcoma is an aggressive and painful bone neoplasm in dogs. Previous studies have reported epidemiological associations suggesting that large body mass, long bone length and the genetics of certain breeds including the Rottweiler are associated with elevated osteosarcoma risk. However, these studies were often limited by selection bias and confounding factors, and have rarely offered insights into breed-associated protection for osteosarcoma. The current study includes 1756 appendicular and axial osteosarcoma cases presenting to VPG Histology (Bristol, UK) compared against a control population of 905,211 dogs without osteosarcoma from primary care electronic patient records in the VetCompass™ dataset. Methods and study design: Retrospective, case-control study. Multivariable logistic regression analysis explored associations between demographic risk factors (including breed, chondrodystrophy, age, sex/neuter status, skull-shape, and body mass) and osteosarcoma of all anatomical sites. Results: We identified several breeds with increased and reduced odds of osteosarcoma. At highest risk were the Rottweiler and Great Dane, with > 10 times the odds of osteosarcoma compared with crossbreds, and the Rhodesian Ridgeback, which has not featured in previous lists of at-risk breeds for osteosarcoma, and had an odds ratio of 11.31 (95% confidence interval 7.37–17.35). Breeds at lowest risk of osteosarcoma (protected breeds) included the Bichon Frise, the French Bulldog and the Cavalier King Charles Spaniel, all with odd ratios of less than 0.30 compared with crossbreds. Body mass was strongly associated with osteosarcoma risk; dogs over 40 kg exhibited osteosarcoma odds of 45.44 (95% confidence interval 33.74–61.20) compared with dogs less than 10 kg. Chondrodystrophic breeds had an osteosarcoma odds ratio of 0.13 (95% confidence interval 0.11–0.16) compared with non-chondrodystrophic breeds. Conclusions: This study provides evidence of strong breed-associated osteosarcoma risk and protection, suggesting a genetic basis for osteosarcoma pathogenesis. It highlights that breeds selected for long legs/large body mass are generally overrepresented amongst at-risk breeds, whilst those selected for short leg length/small body mass are generally protected. These findings could inform genetic studies to identify osteosarcoma risk alleles in canines and humans; as well as increasing awareness amongst veterinarians and owners, resulting in improved breeding practices and clinical management of osteosarcoma in dogs. [ABSTRACT FROM AUTHOR]

Abstract Background Reports of osteoblastic tumours are limited to a few case reports in veterinary medicine. Osteoblastoma-like osteosarcoma has been accepted by the World Health Organization as an intermediate form between an osteosarcoma and osteoblastoma. This type of tumour indicates an osteosarcoma, that may resemble osteoblastoma clinically, histologically, and radiologically and have the capability for metastasis. Osteoblastoma-like osteosarcoma has not been described in veterinary medicine so far. Case presentation An eight-year old cat was presented due to progressive ataxia and paraparesis of the pelvic limbs. Imaging confirmed a well-defined, extradural mass originating from the spinous process of the second thoracic vertebra (T2) leading to severe compression of the spinal cord. Decompressive cytoreduction was achieved by removal of the mass after dorsal laminectomy of T1. After recovering from an acute worsening 3.5 weeks after surgery, the cat had an improved neurological status and the dorsal compression was resolved at follow-up 8 months later. A focal contrast enhancing lesion was still evident at the base of T2 spinous process and lung metastasis was additionally suspected. Based on histopathological, radiographic, and clinical features, an “osteoblastoma-like osteosarcoma” was suspected. Conclusions To the best of our knowledge, this is the first description of this tumour in veterinary medicine. In addition, this case report highlights the difficulty in the diagnosis and definition of osseous neoplasia in cats and provides a literature review.

Aims: The aticularis genu (AG) is the least substantial and deepest muscle of the anterior compartment of the thigh and of uncertain significance. The aim of the study was to describe the anatomy of AG in cadaveric specimens, to characterize the relevance of AG in pathological distal femur specimens, and to correlate the anatomy and pathology with preoperative magnetic resonance imaging (MRI) of AG. Methods: In 24 cadaveric specimens, AG was identified, photographed, measured, and dissected including neurovascular supply. In all, 35 resected distal femur specimens were examined. AG was photographed and measured and its utility as a surgical margin examined. Preoperative MRIs of these cases were retrospectively analyzed and assessed and its utility assessed as an anterior soft tissue margin in surgery. In all cadaveric specimens, AG was identified as a substantial structure, deep and separate to vastus itermedius (VI) and separated by a clear fascial plane with a discrete neurovascular supply. Mean length of AG was 16.1 cm ( ± 1.6 cm) origin anterior aspect distal third femur and insertion into suprapatellar bursa. In 32 of 35 pathological specimens, AG was identified (mean length 12.8 cm ( ± 0.6 cm)). Where AG was used as anterior cover in pathological specimens all surgical margins were clear of disease. Of these cases, preoperative MRI identified AG in 34 of 35 cases (mean length 8.8 cm ( ± 0.4 cm)). Results: AG was best visualized with T1-weighted axial images providing sufficient cover in 25 cases confirmed by pathological findings.These results demonstrate AG as a discrete and substantial muscle of the anterior compartment of the thigh, deep to VI and useful in providing anterior soft tissue margin in distal femoral resection in bone tumours. Conclusion: Preoperative assessment of cover by AG may be useful in predicting cases where AG can be dissected, sparing the remaining quadriceps muscle, and therefore function.

Abstract Background Bizarre parosteal osteochondromatous proliferation (BPOP) is a relatively rare benign extraperiosteal osteochondroma-like proliferative lesion that shares similarities with malignant tumours in terms of morphology. The aetiology of BPOP has yet to be determined and there are no previous reports of BPOP associated with fracture. Case presentation A 57-year-old woman presented with a one-month history of pain and swelling in her right foot, which were worsened by activity and improved with rest. Physical examination revealed a hard, non-mobile mass measuring 1.5 cm × 1.5 cm on the dorsal aspect of the third metatarsal of the right foot. There was overlying erythema and tenderness on palpation. Computed tomography (CT) of the right foot demonstrated a fracture of the neck of the third metatarsal, osteolysis at the fracture site and soft tissue swelling. Bone scintigraphy revealed increased tracer uptake suggesting abnormal bone metabolism at the neck of the third metatarsal. Surgical excision of the lesion was performed. Histopathology and immunohistochemistry confirmed the diagnosis of BPOP. Conclusion BPOP is a rare benign lesion that is commonly misdiagnosed. Differential diagnosis is mainly achieved through imaging and histopathological assessment.

We propose a "A to Z RAM (Radiograph Assessment Method)" for evaluation of Radiograph of patients with a suspected bone tumour. In the current study, ten radiological features with letters 'A, B, C, D, E, F and Z' were used and which included the age of the patient, involved part of the bone, characteristics, content, distinctiveness, the exterior of the bone, fracture, and zone of transition. Four independent observers (orthopaedic oncologists and surgical oncologists) evaluated a set of 30 radiographs of bone tumour selected at random from our hospital database based on A to Z RAM. We classified the lesions into two groups according to the traffic signal system; Green (suspected benign lesion) and Red (suspected malignant lesion). There were 18 (60%) benign bone lesions and 12 (40%) malignant lesions in the current study. 91.6% of malignant tumours and 88.8% of the benign tumours were identified correctly by the four observers. The inter-observer variability with Fleiss kappa was 0.884 (95% CI 0.7–1.03 p-value < 0.05), suggestive of agreement not by chance. These radiographs were again reassessed by the four observers after 3 months. The interobserver variability by Fleiss kappa was 1.0 (95% CI 0.8–1.1) suggesting complete agreement amongst the observers. Both orthopaedic oncologists had intra-observer kappa as 1.0 each and both surgical oncologists had 0.795 and 0.930 respectively. The proposed A to Z RAM is an easy to use and reproducible method for reviewing radiographs in the out-patient department along with clinical findings for better management of patients with suspected bone lesions. The A to Z RAM can be a medical triage tool and subdivide bone lesions into two subgroups i.e. suspected benign lesion with a suggestion of further investigations with MRI and biopsy and suspected malignant lesion with a suggestion of MRI or early referral to a tertiary cancer center with expertise in orthopaedic oncology. The A to Z RAM (Radiologic Assessment Method) is a reproducible method for reviewing radiographs in the out-patient department and can be an aid for better management of patients. A to Z RAM is useful as a medical triage system, subdividing patients according to the probable diagnosis into a suspected benign lesion and suspected malignant lesion. [ABSTRACT FROM AUTHOR]