X-rays radiomics-based machine learning classification of atypical cartilaginous tumour and high-grade chondrosarcoma of long bones.

BACKGROUND: Atypical cartilaginous tumour (ACT) and high-grade chondrosarcoma (CS) of long bones are respectively managed with active surveillance or curettage and wide resection. Our aim was to determine diagnostic performance of X-rays radiomics-based machine learning for classification of ACT and high-grade CS of long bones. METHODS: This retrospective, IRB-approved study included 150 patients with surgically treated and histology-proven lesions at two tertiary bone sarcoma centres. At centre 1, the dataset was split into training (n = 71 ACT, n = 24 high-grade CS) and internal test (n = 19 ACT, n = 6 high-grade CS) cohorts, respectively, based on the date of surgery. At centre 2, the dataset constituted the external test cohort (n = 12 ACT, n = 18 high-grade CS). Manual segmentation was performed on frontal view X-rays, using MRI or CT for preliminary identification of lesion margins. After image pre-processing, radiomic features were extracted. Dimensionality reduction included stability, coefficient of variation, and mutual information analyses. In the training cohort, after class balancing, a machine learning classifier (Support Vector Machine) was automatically tuned using nested 10-fold cross-validation. Then, it was tested on both the test cohorts and compared to two musculoskeletal radiologists' performance using McNemar's test. FINDINGS: Five radiomic features (3 morphology, 2 texture) passed dimensionality reduction. After tuning on the training cohort (AUC = 0.75), the classifier had 80%, 83%, 79% and 80%, 89%, 67% accuracy, sensitivity, and specificity in the internal (temporally independent) and external (geographically independent) test cohorts, respectively, with no difference compared to the radiologists (p ≥ 0.617). INTERPRETATION: X-rays radiomics-based machine learning accurately differentiates between ACT and high-grade CS of long bones. FUNDING: AIRC Investigator Grant.

Long-term longitudinal study on swine VML model.

BACKGROUND: Volumetric Muscle Loss (VML), resulting from severe trauma or surgical ablation, is a pathological condition preventing myofibers regeneration, since skeletal muscle owns the remarkable ability to restore tissue damage, but only when limited in size. The current surgical therapies employed in the treatment of this pathology, which particularly affects military personnel, do not yet provide satisfactory results. For this reason, more innovative approaches must be sought, specifically skeletal muscle tissue engineering seems to highlight promising results obtained from preclinical studies in VML mouse model. Despite the great results obtained in rodents, translation into human needs a comparable animal model in terms of size, in order to validate the efficacy of the tissue engineering approach reconstructing larger muscle mass (human-like). In this work we aim to demonstrate the validity of a porcine model, that has underwent a surgical ablation of a large muscle area, as a VML damage model. RESULTS: For this purpose, morphological, ultrasound, histological and fluorescence analyses were carried out on the scar tissue formed following the surgical ablation of the peroneus tertius muscle of Sus scrofa domesticus commonly called mini-pig. In particular, the replenishment of the damaged area, the macrophage infiltration and the vascularization at different time-points were evaluated up to the harvesting of the scar upon six months. CONCLUSION: Here we demonstrated that following VML damage, there is an extremely poor regenerative process in the swine muscle tissue, while the formation of fibrotic, scar tissue occurs. The analyses performed up to 180 days after the injury revealed the development of a stable, structured and cellularized tissue, provided with vessels and extracellular matrix acquiring the status of granulation tissue like in human.

MRI radiomics-based machine learning for classification of deep-seated lipoma and atypical lipomatous tumor of the extremities.

PURPOSE: To determine diagnostic performance of MRI radiomics-based machine learning for classification of deep-seated lipoma and atypical lipomatous tumor (ALT) of the extremities. MATERIAL AND METHODS: This retrospective study was performed at three tertiary sarcoma centers and included 150 patients with surgically treated and histology-proven lesions. The training-validation cohort consisted of 114 patients from centers 1 and 2 (n = 64 lipoma, n = 50 ALT). The external test cohort consisted of 36 patients from center 3 (n = 24 lipoma, n = 12 ALT). 3D segmentation was manually performed on T1- and T2-weighted MRI. After extraction and selection of radiomic features, three machine learning classifiers were trained and validated using nested fivefold cross-validation. The best-performing classifier according to previous analysis was evaluated and compared to an experienced musculoskeletal radiologist in the external test cohort. RESULTS: Eight features passed feature selection and were incorporated into the machine learning models. After training and validation (74% ROC-AUC), the best-performing classifier (Random Forest) showed 92% sensitivity and 33% specificity in the external test cohort with no statistical difference compared to the radiologist (p = 0.474). CONCLUSION: MRI radiomics-based machine learning may classify deep-seated lipoma and ALT of the extremities with high sensitivity and negative predictive value, thus potentially serving as a non-invasive screening tool to reduce unnecessary referral to tertiary tumor centers.

Primary intraosseous solitary fibrous tumor: an extremely rare case report and brief review of the literature.

Solitary fibrous tumor (SFT), a rare mesenchymal neoplasm of fibroblastic origin, was initially discovered in the mediastinal pleura and then described in many extra-pleural sites.The reports of primary solitary fibrous tumor of bone are extremely rare and only a few cases have been previously mentioned in the literature, most of which in flat and short bones.Here we present the case of a 53-year-old female, who was referred to the emergency department of a peripheral hospital after an accidental fall. Imaging studies revealed an intertrochanteric fracture with an underlying intramedullary lytic lesion. A biopsy was performed and a diagnosis of Ewing sarcoma was initially suggested. She arrived at our hospital where we reevaluated the case. The biopsy was reviewed and a diagnosis of intraosseous SFT was proposed. She underwent en-block resection of the proximal right femur.Primary SFTs of the bone are, like in our case, easily misdiagnosed due to the low specificity of the imaging studies and the extreme rarity of the localization. An accurate diagnosis and early resection are very important and with careful long-term follow-up is essential, particularly in those who with malignant behavior, for the early detection of possible recurrence or metastasis.

Malignant Transformation of Giant Cell Tumour of Bone: A Review of Literature and the Experience of a Referral Centre.

Giant cell tumour of bone (GCTB) is a benign, locally aggressive primary bone neoplasm that represents 5% of all bone tumours. The principal treatment approach is surgery. Although generally GCTB is considered only a locally aggressive disease, it can metastasise, and lung metastases occur in 1-9% of patients. To date, only the use of denosumab has been approved as medical treatment for GCTB. Even more rarely, GCTB undergoes sarcomatous transformation into a malignant tumour (4% of all GCTB), but history of this malignant transformation is unclear and unpredictable. Considering the rarity of the event, the data in the literature are few. In this review, we summarise published data of GCTB malignant transformation and we analyse three cases of malignant transformation of GCTB, evaluating histopathology, genetics, and radiological aspects. Despite the rarity of this event, we conclude that a strict follow up is recommended to detect early malignant transformation.

Narrative Medicine: A Digital Diary in the Management of Bone and Soft Tissue Sarcoma Patients. Preliminary Results of a Multidisciplinary Pilot Study.

BACKGROUND: Guidelines for the implementation of narrative medicine in clinical practice exist; however, in Italy, no standard methodology is currently available for the management of oncological patients. Since 2017, at the "Regina Elena" National Cancer Institute, studies using "digital narrative diaries" (DNMLAB platform) have been carried out; this article focuses on a pilot, uncontrolled, real-life study aiming to evaluate the utility of DNM integrated with the care pathway of patients with bone and limb soft tissue sarcomas. METHODS: Adult patients completed the diary during treatment or follow-up by writing their narrative guided by a set of narrative prompts. The endpoints were: (a) patients' opinions about therapeutic alliance, awareness, and coping ability; (b) healthcare professionals' (HCPs') opinions about communication, therapeutic alliance, and information collection. Open- and closed-ended questions (Likert score: 1-5) were used to assess the items. RESULTS: At the interim analysis of data from seven patients and five HCPs, DNM was shown to improve: (a) the expression of patients' point of view, the perception of effective taking charge, disease awareness, and self-empowerment (score: 4.8/5); (b) patients' communication, relationships, and illness knowledge (score: 4.6-4.8/5). CONCLUSIONS: The preliminary results supported the need to integrate patients' narratives with clinical data and encourage further research.

Prognostic Value of Pre-Treatment [18F]FDG PET/CT Texture Analysis in Undifferentiated Soft-Tissue Sarcoma.

BACKGROUND: Undifferentiated soft-tissue sarcomas (USTS) are one of the most common sarcoma histotypes in adults. The standard of care is surgical excision plus adjuvant radiotherapy, while the use of perioperative chemotherapy is still controversial. The aim of this study was to investigate the value of pre-treatment [18F]FDG PET/CT conventional metrics and textural features in predicting disease-free survival (DFS) and overall survival (OS) in patients with USTS of the limbs and trunk. METHODS: [18F]FDG PET/CT scans of 51 consecutive patients with locally advanced USTS were retrospectively evaluated. Conventional and textural PET parameters were analysed and tested as predictive factors for DFS and OS. RESULTS: During a median follow up of 50.7 months, 23 (45.1%) and 29 (56.9%) patients had death or disease progression, respectively. Univariate analysis revealed a significant association for perioperative treatment, PET volumetric parameters and the textural feature GLCM_correlation with DFS and OS. In multivariate analysis, perioperative treatment and GLCM_correlation were the only independent factors, allowing stratification of the population into three different prognostic classes. CONCLUSION: GLCM_correlation can identify USTS at high risk of relapse and death, thus helping to optimize the perioperative treatment of patients.

The role of minimally invasive plate osteosynthesis (MIPO) technique for treating 3- and 4-part proximal humerus fractures in the elderly - a case study.

Background and aim of the work Proximal humeral fractures incidence in the elderly population is increasing. Treatment management is complicated by fracture complexity and patients' comorbidities. The aim of our prospective study is the outcome evaluation of the role of minimally invasive plate osteosynthesis (MIPO) for elderly patients with a 3- or 4-parts proximal humeral fractures having an intact medial wall.   Methods We included n=42 unilateral 3- and 4-parts proximal humeral fractures treated with MIPO: 20 4-part fractures and 22 were 3-parts fractures were included. 17 patients identified as male and 25 as female (mean age 84yo).  A trans-deltoid approach has been used with minimal surgical exposure and tissue damage to preserve the local tissue for early shoulder mobilization.   Results At follow-up, the DASH recorded mean value was 72, while the Constant mean score was 68. Complications have been recorded in 23,8% of patients with 4-parts fractures having the highest complication frequency. Mean shoulder joint ROM was recorded: anterior elevation 75°, lateral elevation 80°, abduction 90°, intra-rotation 50°, extra-rotation 25°. The following factors were identified influencing the outcome: >8mm calcar fragment, head valgus impaction and periosteal medial hinge preservation.   Conclusions The increase in population longevity matches the increase in complex humeral fracture frequency. We strongly for management consensus for proximal humerus fracture, in a similar way as for neck femoral fractures. MIPO is excellent in reducing soft tissue damage and complications for elderly patients with limited functional demand.

Wide Surgery in the Cervical Spine: Indications, Results, and Complications in a Series of 30 Patients Affected by Primary Bone Tumors.

BACKGROUND: En bloc surgery is the mainstay treatment for primary malignant bone tumors, as well as in the cervical spine. Unfortunately, literature on the topic is limited to case reports and small series. METHODS: We reviewed all patients affected by primary cervical spine bone tumors treated with en bloc surgeries from 1996 to 2016 and identified 30 eligible cases. We evaluated the clinical presentation and tumor characteristics and reported surgical results, complications, recurrence, and survival rates. RESULTS: Only 17 of 30 patients had not been previously treated at presentation. Osteosarcoma and chordoma were the most frequent tumors, and pain was reported in all cases. En bloc spondylectomy, hemispondylectomy, and posterior arch en bloc resection were performed in 16, 12, and 2 patients, respectively. The obtained margin was adequate (wide and marginal) in 60% of cases and intralesional in the remaining cases. Two deaths occurred in the immediate postoperative period. Neurological deterioration, dural tear, and dysphagia were the most frequent complications. The 5-year local recurrence-free survival was 70.4%. The recurrence rate was 38.5% and 11.7% in previously and non-previously treated patients, respectively (χ2: 2.94; P = 0.086). Overall survival at 5 years was 58% and 47% for all series and malignant tumors, respectively. CONCLUSION: Primary cervical spine bone tumors present a difficult approach. Findings suggest that patients treated with en bloc surgery show recurrence and survival rates comparable to the same tumors located in the thoracolumbar spine.

3D-Printed Titanium Custom-Made Prostheses in Reconstruction after Pelvic Tumor Resection: Indications and Results in a Series of 14 Patients at 42 Months of Average Follow-Up.

Wide resection is currently considered the mainstay treatment for primary bone tumors. When the tumor is located in anatomically complex segments, 3D-Printed Titanium Custom-Made Prostheses (3DPTCMP) are possible reconstructive solutions. The aim of the present paper is to analyze indications, results and complications of a series of 14 patients who underwent pelvis reconstruction with 3DPTCMP after tumor removal from January 2015 to December 2019. Chondrosarcoma was the main histology; indications were tumors located in the acetabular area without enough residual bone to support a cup with an iliac stem, and tumors located near the sacrum-iliac joint. The margins were wide in 12 cases, and marginal and intralesional in one case each. In three cases, resection also included the sacrum-iliac joint, so a spine stabilization was performed and linked to the pelvic prosthesis; The average MSTS score was 46.3%; the 5-year local recurrence-free survival was 85.7%. Wound dehiscences were the main complication, resolved with multiple debridements; nevertheless, prosthesis removal was necessary in one case. Currently, the 3DPTCMP is an effective resource for reconstruction after resection of tumors located in the pelvis. Further studies are necessary to value long-term results; more strategies are necessary to try to reduce the infection rate and improve osteointegration.

Biofabricating murine and human myo-substitutes for rapid volumetric muscle loss restoration.

The importance of skeletal muscle tissue is undoubted being the controller of several vital functions including respiration and all voluntary locomotion activities. However, its regenerative capability is limited and significant tissue loss often leads to a chronic pathologic condition known as volumetric muscle loss. Here, we propose a biofabrication approach to rapidly restore skeletal muscle mass, 3D histoarchitecture, and functionality. By recapitulating muscle anisotropic organization at the microscale level, we demonstrate to efficiently guide cell differentiation and myobundle formation both in vitro and in vivo. Of note, upon implantation, the biofabricated myo-substitutes support the formation of new blood vessels and neuromuscular junctions-pivotal aspects for cell survival and muscle contractile functionalities-together with an advanced muscle mass and force recovery. Altogether, these data represent a solid base for further testing the myo-substitutes in large animal size and a promising platform to be eventually translated into clinical scenarios.

The IlluminOss® photodynamic bone stabilization system for pathological osteolyses and fractures of the humerus: indications, advantages and limits in a series of 12 patients at 24 months of minimum follow-up.

BACKGROUND: Locked titanium nails are considered the reference treatment for metastatic bone lesions of the humerus in patients with aggressive histotypes, high risk of fracture or when estimated survival is lower than 6 months.Nevertheless, they are responsible for CT and MRI artifacts which interfere with postoperative radiotherapy and follow-up.The IlluminOss® is an intramedullary stabilization system which is introduced inside the humeral canal in a deflated state, and is then distended with a monomer which hardens after exposure to blue light,stabilizing the segment; it does not cause artifacts, allowing easier and more effective radiotherapy and follow-up. The aim of this study is to report our experience, indications, possible advantages and limitations of this stabilization system at 24 months of minimum follow-up in a series of 12 patients affected by pathological fractures or impending fractures of the humerus. METHODS: This is a retrospective case-series that included all patients who underwent surgery with the IlluminOss® Photodynamic Bone Stabilization System for pathological osteolyses and fractures of the humerus. Intraoperative and postoperative complications were valued. RESULTS: 12 patients and 13 procedures were included in the study. All surgeries were performed without intraoperative complications. No early postoperative complications were noted. The wounds healed in all cases and stitches were removed at two weeks from surgery, so the patients were able to perform chemotherapy after three weeks. All patients except one had a painless active range of motion which reached 90°.The VAS score was 7 preoperatively and 2.6 at one month from surgery. Pain relief was also associated to radiotherapy and chemotherapy. Unfortunately, two nail ruptures were reported at 4 and 12 months of follow-up. No artifacts were noted in the postoperative CT scans so the radiotherapy plans were easily performed without the need of dose compensation. CONCLUSIONS: The IlluminOss® intramedullary stabilization system can provide primary stability in humeral fractures and impending fractures;the surgical technique is easy and minimally invasive.Moreover,it does not present artifacts at postoperative imaging,probably giving a better chance to perform prompt radiotherapy and chemotherapy.However, randomized clinical studies are necessary to verify its potential strength and if precocious adjuvant radio- and chemotherapy are associated to a reduction of the local progression rate.

Skeletal Muscle-Derived Human Mesenchymal Stem Cells: Influence of Different Culture Conditions on Proliferative and Myogenic Capabilities.

Skeletal muscle tissue is characterized by restrained self-regenerative capabilities, being ineffective in relation to trauma extension both in time span (e.g., chronic diseases) and in size (e.g., large trauma). For these reasons, tissue engineering and/or cellular therapies represent a valuable solution in the cases where the physiological healing process failed. Satellite cells, the putative skeletal muscle stem cells, have been the first solution explored to remedy the insufficient self-regeneration capacity. Nevertheless, some limitation related to donor age, muscle condition, expansion hitch, and myogenic potentiality maintenance have limited their use as therapeutic tool. To overcome this hindrance, different stem cells population with myogenic capabilities have been investigated to evaluate their real potentiality for therapeutic approaches, but, as of today, the perfect cell candidate has not been identified yet. In this work, we analyze the characteristics of skeletal muscle-derived human Mesenchymal Stem Cells (hMSCs), showing the maintenance/increment of myogenic activity upon differential culture conditions. In particular, we investigate the influence of a commercial enriched growth medium (Cyto-Grow), and of a medium enriched with either human-derived serum (H.S.) or human Platelet-rich Plasma (PrP), in order to set up a culture protocol useful for employing this cell population in clinical therapeutic strategies. The presented results reveal that both the enriched medium (Cyto-Grow) and the human-derived supplements (H.S. and PrP) have remarkable effects on hMSCs proliferation and myogenic differentiation compared to standard condition, uncovering the real possibility to exploit these human derivatives to ameliorate stem cells yield and efficacy.

The advantages of carbon fiber based orthopedic devices in patients who have to undergo radiotherapy.

BACKGROUND AND OBJECTIVES: The modern approach to primary and secondary muscular skeletal tumors is multidisciplinary. The right combination of chemotherapy, surgery and radiotherapy (RT) makes obtaining local and distant disease control more likely. When surgery is indicated, radiotherapy often has a fundamental role as an adjuvant treatment; however, the titanium alloy instrumentations interfere with Radiotherapy setting, decreasing its effectiveness. It is common opinion that carbon fiber-reinforced devices are convenient in case of adjuvant RT in muscular skeletal oncology. The aim of the study is to support this intuition with experimental data, verifying the more accurate estimation of the delivered dose during RT, comparing Carbon Fiber-Reinforced PEEK (CFRP) plates with titanium-alloy orthopedic devices in order to evaluate their effects on target volume identification and dose distribution for radiation treatment. METHODS: Phantoms were then irradiated with a linear accelerator Varian 2100 C/D with photon beams of 6 and 15 MV energies. Absorbed dose in the point of interest was verified by EBT3 gafchromic films above and below the two materials. Images from CT simulations were also analyzed in terms of Hounsfield numbers in patients with titanium and carbon fiber orthopedic implants in the spine or in the femur. RESULTS: For a 6 MV photon beam, the doses measured just under the titanium-alloy plate were less than approximately 20% of the value calculated by the TPS. For a 15 MV beam energy, these differences were slightly lower. Using CFRP plate, the difference between measured and calculated doses was within ±3% for both energies, which was comparable with the statistical uncertainties. In the cases of simulated treatment of humerus titanium implants, the difference varies in range ± 10% with hot spot of + 10% and cold spot of -15%. CONCLUSIONS: The use of CFRP for orthopedic devices and implants provides a valuable advantage in identifying the target due to the reduction of artifacts. Clear imaging of the soft tissues surrounding the bone is useful and reduces the discrepancies between calculated/delivered and measured doses, generating a more homogeneous dose distribution. Furthermore, there is a significant benefit in detecting the state of disease in CT imaging during the follow-up of treated patients. In-vivo studies are encouraged to verify whether a more effective radiotherapy leads to a decrease in local recurrence and local progression.

The Real-Life Journey of Elderly Patients in Soft Tissue and Bone Sarcomas: A Retrospective Analysis from a Sarcoma Referral Center.

The high complexity of multimodality treatment frequently results in undertreatment of elderly sarcoma patients, and this may be one of the factors that influence their prognosis. We describe the real-life approach to a population of patients aged over 70 with both soft tissue (STS) and bone sarcomas (BS) followed by our Sarcoma Disease Management Team from 2012 to 2017. One-hundred and twenty-three patients with a median age of 77 years (range: 70-92) were identified. STS were the most common histological subtypes (94%) and the grade was high in 79/123 patients (64%). At diagnosis, 88% of patients had localized disease (LD) and 12% were metastatic (MD). Overall, 96% of patients with LD underwent surgery, 46/54 (85%) with high grade STS patients underwent complementary radiotherapy, and 10/54 (19%) received adjuvant treatments. Twelve out of 33 patients who relapsed (36%) underwent local therapies. Seventeen (52%) and eight (24%) patients were treated with first-line and second-line medical treatments, respectively. Tolerability to systemic treatments was fairly good. Overall, 21% of the patients with advanced disease were candidates for best supportive care alone. Our case series of elderly patients with both STS and BS shows that personalized multidisciplinary treatment can nevertheless be offered to this frail population in order to control the evolution of disease.

Diagnostic and Clinical Impact of 18F-FDG PET/CT in Staging and Restaging Soft-Tissue Sarcomas of the Extremities and Trunk: Mono-Institutional Retrospective Study of a Sarcoma Referral Center.

BACKGROUND: Soft-tissue sarcomas (STS) represent a wide heterogeneous class of rare tumors. The exact role 18F-fluorodeoxyglucose positron emission/computed tomography (18F-FDG PET/CT) in the evaluation of STS is not well established. The aim of the present study was to evaluate how the use of 18F-FDG PET/CT in STS could influence patient therapy planning, looking for a possible added value over computed tomography and magnetic resonance imaging-the most used modalities in the study of STS. Differences in SUVmax according to histologic subtype and tumor grade were also considered. METHODS: a total of 345 consecutive 18F-FDG PET/CT scans performed for initial staging (n = 171) or for suspected disease relapse (n = 174) in 282 patients with STS extracted from the local Information System database were retrospectively reviewed. RESULTS: 18F-FDG PET/CT altered therapy planning in 80 cases (16.4% for staging and 29.9% in restaging), both for disease upstaging (58.8%) and downstaging (41.2%) Conclusions: 18F-FDG PET/CT could significantly influence management of patients with STS, particularly for restaging.

Reorganization Tips from a Sarcoma Unit at Time of the COVID-19 Pandemic in Italy: Early Experience from a Regional Referral Oncologic Center.

Since the World Health Organization declared the novel coronavirus outbreak a global health emergency, Italy's lockdown was declared on 9 March 2020. Elective orthopedic surgery was forced to stop to allow the healthcare system to face the emergency. However, many orthopedic oncology cases could not be postponed. The aim of this study was to report the experience in managing sarcoma patients and the reorganization of a cancer center in an attempt to maintain it free from COVID-19. A Coronavirus Crisis Unit was established by the health directorate coordination in order to adopt specific procedures. General rules of screening and social distancing were applied in different health settings (entrance check point, hospital inward, outpatient clinic, operative room). Regarding oncologic orthopedics, priority was given to bone and soft tissue sarcomas, metastases and aggressive benign tumors at risk of impending or pathologic fracture. Precise indications were followed to manage first outpatient visits, patients undergoing surgery and follow-up. Meticulous adherence to rules among patients and personnel and collaboration between leadership and medical staff in order to continue to perform multidisciplinary treatment protocols, maintain the availability of infrastructural spaces and source protective equipment, swabs and screening samples have been successful in the aim towards a safe cure for cancer patients.

Osteoid osteoma of the proximal phalanx of the hallux: a case report of a challenging diagnosis.

Osteoid osteoma is a benign bone lesion that accounts for approximately 10% to 12% of all benign bone tumors. More than 80% of lesions occur in patients between 5 to 25 years old; males are more commonly affected with a ratio of 3:1. The foot is rarely involved: its involvement is less than 4% in the foot and of 1.7% in the metatarsals. In this paper we discuss the case of a 27-years-old woman with a 12 months follow-up, presented with an osteoid osteoma of the proximal phalanx of the great toe that underwent an en-bloc excision of the lesion and subsequent filling with cancellous autograft from the ipsilateral calcaneus.

The giant aggressive chondroma: A rare entity, a difficult approach.

INTRODUCTION: enchondromas rarely exceed 3-6 cm in long bones. Although the risk of developing secondary chondrosarcoma has been reported up to 4% in solitary lesions, it is not known if size represents a risk factor for transformation. OBJECTIVE: to describe three exceptional cases of enchondromas of the entire femur whereof one dedifferentiated in chondrosarcoma. RESULTS: two patients present stable disease at 5 and 6 years of follow-up; the third, already diagnosed with a dedifferentiated chondrosarcoma, died 14 months after the index surgery for systemic disease. CONCLUSION: based on these observations, our hypothesis is that lesion size is an important risk factor for malignant transformation.

A Rare Case of First Metatarsal Extrusion: Results of Treatment After 12 Months.

We present the case of a 21-year-old male with 12 months' follow-up after reimplantation of a completely extruded first metatarsal. The patient had a motorcycle accident involving his right foot and ankle, with multiple lesser metatarsal fractures, lateral malleolus fracture, and a total first metatarsal extrusion (without fracture) through a large dorso-medial forefoot wound. The extruded bone was recovered at the site of the motor vehicle accident and was transported to the hospital with the patient. Before the reimplantation surgery was undertaken, the first metatarsal was immersed in a chlorhexidine solution for 20 minutes and then washed in an antibiotic solution. Metatarsal fixation was performed with Kirschner wires; the lateral malleolus fracture was fixed with plate and screws. An external fixator was then applied. Throughout the 12-month follow-up period, there was no evidence of infection. At the present time, this case suggests that, after antiseptic cleansing and prompt surgery, extruded first metatarsal reimplantation is possible with a reasonable degree of clinical success.