Objectives. We evaluated the accuracy of augmented reality (AR)-based navigation assistance through simulation of bone tumours in a pig femur model. Methods. We developed an AR-based navigation system for bone tumour resection, which could be used on a tablet PC. To simulate a bone tumour in the pig femur, a cortical window was made in the diaphysis and bone cement was inserted. A total of 133 pig femurs were used and tumour resection was simulated with AR-assisted resection (164 resection in 82 femurs, half by an orthropaedic oncology expert and half by an orthopaedic resident) and resection with the conventional method (82 resection in 41 femurs). In the conventional group, resection was performed after measuring the distance from the edge of the condyle to the expected resection margin with a ruler as per routine clinical practice. Results. The mean error of 164 resections in 82 femurs in the AR group was 1.71 mm (0 to 6). The mean error of 82 resections in 41 femurs in the conventional resection group was 2.64 mm (0 to 11) (p < 0.05, one-way analysis of variance). The probabilities of a surgeon obtaining a 10 mm surgical margin with a 3 mm tolerance were 90.2% in AR-assisted resections, and 70.7% in conventional resections. Conclusion. We demonstrated that the accuracy of tumour resection was satisfactory with the help of the AR navigation system, with the tumour shown as a virtual template. In addition, this concept made the navigation system simple and available without additional cost or time. Cite this article: H. S. Cho, Y. K. Park, S. Gupta, C. Yoon, I. Han, H-S. Kim, H. Choi, J. Hong. Augmented reality in bone tumour resection: An experimental study. Bone Joint Res 2017;6:137–143

Primary bone tumours of the clavicle are rare. Currently the existing literature is limited to a single case series and case reports or cases. Information regarding the patient's demographics and tumour types is therefore limited. The aim of this study was to investigate the and also suggest a management protocol for suspected primary bone tumours of the clavicle. We retrospectively reviewed the Scottish Bone Tumour Register from January 1971 to January 2012 and included all primary bone tumours of the clavicle. We identified only sixteen primary bone tumours over forty one year's highlighting the rarity of these tumours. There were ten benign and six malignant tumours with a mean age of 32 years (Range 4 to 66). The average presentation to orthopaedics after onset of symptoms was two months with five patients presenting following a pathological fracture. Malignant tumour types identified were consistent with previous literature with two cases of Ewing's sarcoma and osteosarcoma and a single case of osteosarcoma post radiotherapy and a single case of chondrosarcoma. Benign tumours were treated effectively with intralesional procedures. Malignant tumours were treated with wide local excision and subtotal or total clavicle excision. We suggest an investigatory and treatment protocol for patients with a suspected primary bone tumour of the clavicle. This is the largest series of primary bone tumours of the clavicle in the literature

Primary bone tumours of the talus are rare. Currently the existing literature is limited to a single case series and case reports or cases described in series of foot tumours. Information regarding the patient's demographics and tumour types is therefore limited. The aim of this study was to investigate these questions and also suggest a management protocol for suspected primary bone tumours of the talus. We retrospectively reviewed the Scottish Bone Tumour Register from January 1954 to May 2010 and included all primary bone tumours of the talus. We identified only twenty three bone tumours over fifty six years highlighting the rarity of these tumours. There were twenty benign and three malignant tumours with a mean age of twenty eight years. A delay in presentation was common with a mean time from onset of symptoms to diagnosis of ten months. Tumour types identified were consistent with previous literature. We identified cases of desmoplastic fibroma and intraosseous lipodystrophy described for the first time. We suggest an investigatory and treatment protocol for patients with a suspected primary bone tumour of the talus. This is the largest series of primary bone tumours of the talus in the literature

Bony tumours of the foot account for approximately 3% of all osseous tumours. However, literature regarding os calcis tumours comprises individual case reports, short case series or literature reviews, with the last large case series in 1973. We retrospectively reviewed the medical notes and imaging for all patients with calcaneal tumours recorded in the Scottish Bone Tumour Registry since the 1940's. Demographics, presentation, investigation, histology, management and outcome were reviewed. 38 calcaneal tumours were identified. Male to female ratio 2:1, mean age at presentation 30 with heel pain and swelling, average length of symptoms 9 months. 4 cases present with pathological fracture. 24 tumours benign including 6 unicameral bone cysts, 3 chondroblastoma, 3 PVNS with calcaneal erosion, and a wide variety of individual lesions. 13 malignant tumours comprising 6 osteosarcoma, 5 chondrosarcoma and 2 Ewings sarcoma. 1 metastatic carcinoma. Tumours of the calcaneus frequently are delayed in diagnosis due to their rarity and lack of clinician familiarity. They are more common in men and have a 1 in 3 risk of malignancy, covering a wide variety of lesions. Outcome is dependent on early diagnosis, timely surgery and most importantly neo-adjuvant chemotherapy. Diagnosis is often made on plain radiograph but MRI is the gold standard. We present the largest case series of calcaneal tumours, from our experience with the Scottish Bone Tumour Registry. Despite their rarity clinicians should maintain a high index of suspicion as accurate and timely diagnosis is important to management and outcome

Primary bony tumours of the elbow account for approximately 1% of all osseous tumours. The delayed diagnosis is commonly reported in the literature as a result of lack of clinician familiarity. We present the largest series of primary bone tumours of the elbow in the English literature. We sought to identify characteristics specific to primary elbow tumours and compare these to the current literature. We discuss cases of misdiagnosis and reasons for any delay in diagnosis. The authors also recommend a collaborative protocol for the diagnosis and management of these rare tumours. A prospectively collected national database of all bone tumours is maintained by an independent clerk. The registry and case notes were retrospectively reviewed from January 1954 until June 2013. Eighty cases of primary osseous elbow tumours were studied. Tumours were classified as benign or malignant and then graded according to the Enneking spectrum. There were no benign latent cases in this series. All cases in this series required surgical intervention. These cases presented with persistent rest pain, with or without swelling. The distal humerus was responsible for the majority and most aggressive of cases. The multidisciplinary approach at a specialist centre is integral to management. Misdiagnosis was evident in 12.5 % of all cases. Malignant tumours carried a 5-year mortality of 61%. Benign tumours exhibited a 19% recurrence rate and in particular, giant cell tumour was very aggressive. The evolution in treatment modalities has clearly benefited patients. Clinicians should be aware that elbow tumours can be initially misdiagnosed as soft tissue injuries or cysts. The suspicion of a tumour should be raised in the patient with unremitting, unexplained non-mechanical bony elbow pain. We suggest an investigatory and treatment protocol to avoid a delay to diagnosis. With high rates of local recurrence, we recommend regular postoperative reviews

Bizarre parosteal osteochondromatous proliferation (BPOP) is a benign lesion of bone originally described by Nora et al in 1983. To date there are no UK-based case series in the literature. Here we present the Scottish Bone Tumour Registry (SBTR) experience of this rare lesion. A retrospective analysis of SBTR records was performed. Histological specimens were re-examined by a consultant musculoskeletal oncology pathologist. Radiographs were re-reported by a consultant musculoskeletal radiologist. From 1983-2009, 13 cases were identified; 6 male, 7 female. Age ranged from 13-65. All patients presented with localised swelling. Pain was present in 5 and trauma in 2. 9 lesions affected the hand, 3 the foot, and 1 the tibial tuberosity. 12 lesions were excised and 1 curetted. There were 7 recurrences of which 6 were excised. 1 patients' recurrence was not treated. 1 lesion recurred a second time. This was excised. There were no metastases. Radiographs typically showed densely mineralised lesions contiguous with an uninvolved cortex. Cortical breakthrough was present in 1 case and scalloping in another. Histology characteristically showed hypercellular cartilage with pleomorphism and calcification/ossification without atypia; bone undergoing maturation; and a spindle-cell stroma. SBTR records indicate that BPOP is a rare lesion with no sex predilection that affects patients over a wide age range. Minor antecedent trauma was present in only 2 cases. In agreement with Nora et al. we feel that trauma is unlikely to represent an aetiological factor. Recurrence was over 50% in this series. Although this is similar to that found in other reports, it may indicate that more extensive resection is required for this aggressive lesion. Finally, although radiological/histological findings are often bizarre there have been no reported metastases and so it is important that BPOP is not mistaken for, or treated as, a malignant process such as chondrosarcoma

Background

In certain clinical situations, complex local anatomy and limitations of surgical exposure can make adequate and bone tumor ablation, resection and reconstruction very challenging. We wished to review our clinical experience and accuracy achieved with entirely virtually planned single stage tumor ablation/resection and reconstructions.

In the past decades, a huge amount of effort has been devoted to translate evidence based on standard preclinical models of bone tumours to effective tools for clinical applications. Although cancer is a genetic disease, hence the emphasis on -omics approaches, the complexity of cancer tissue, a mix of competing clones of transformed elements that react differently to microenvironmental stimuli, may hardly be reproduced by standard approaches. Cost, biological differences and ethical concerns are increasingly recognized as weaknessess of animal models. To overcome these limitations and provide reliable, reproducible, and affordable tools for predicting the effectiveness of treatments, environmental-controlled 3D cultures and co-cultures (spheroids, organoids) coupled with microfluidics and advanced imaging have recently being considered as effective instrument to increase knowledge on the pathophysiology of bone tumours and define effective therapeutic solutions

Abstract. Background. Schwannomas are slow-growing, benign tumours normally originating from the Schwann cells of the nerve sheath. Intraosseous schwannoma accounts for 0.175% of primary bone tumours and extremely rare especially outside the axial skeleton. Monoclonal gammopathy has been associated with soft tissue schwannomas but never with the intraosseous variety. Presenting problem. A 55-year-old woman with a background of monoclonal gammopathy of undetermined significance (MGUS) presented with a 2-year history of right thigh pain. CT scan showed a well defined, lytic lesion with a thin peripheral rim of sclerosis in the midshaft of the femur. MRI displayed a hyperintense, well marginated and homogenous lesion. Definitive diagnosis was made based on the classical histopathological appearance of schwannoma. Clinical management. We managed our patient with local curettage and prophylactic cephalomedullary nailing on the basis of a high mirel score. Discussion. Intraosseous schwannomas are poorly understood but most commonly reported in middle-aged women. Radiologically, their differential diagnosis includes malignant bone tumours, solitary bone cysts, aneurysmal bone cysts and giant cell tumours. As a result, they are usually diagnosed incidentally on histology. Although malignant transformation is possible in soft tissue schwannomas, all intraosseous schwannomas reported to date have been benign. This case demonstrates the importance of suspecting intraosseous schwannoma as a differential diagnosis for lytic bone lesions to avoid the overtreatment of patients. We also highlight monoclonal gammopathy of undetermined significance as a potential risk factor for a poorly understood disease and make recommendations about the appropriate management of these lesions. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

The in vitro mimicking of bone microenvironment for the study of pathologies is a challenging field that requires the design of scaffolds with suitable morphological, structural and cytocompatible properties. During last years, 3D in vitro tumour models have been developed to reproduce mechanical, biochemical and structural bone microenvironment elements, allowing cells to behave as in vivo. In this work, gas foamed polyether urethane foams (PUF) and 3D printed thermoplastic polyether urethane (3DP-PU) designed with different patterns are proposed as scaffolds for in vitro model of bone tissue. Surface coatings for a biomimetic behaviour of the 3D scaffold models were also investigated. Morphological, chemico-physical, mechanical properties, and biological in vitro behaviour were investigated. PUFs for metastases investigation. The suitability of PUF as 3D in vitro model to study the interactions between bone tumour initiating cells and the bone microenvironment was investigated. PUF open porosity (>70%) appeared suitable to mimic trabecular bone structure. Human adipose derived stem cells (ADSC) were cultured and differentiated into osteoblast lineage on the PU foam, as confirmed by Alizarin Red staining and RT-PCR, thus offering a bone biomimetic microenvironment to the further co-culture with bone derived tumour-initiating cells (MCFS). Tumour aggregates were observed after three weeks of co-culture by e-cadherin staining and SEM; modification in CaP distribution was identified by SEM-EDX and associated to the presence of tumour cells. 3DP-PU as tumour bone model. 3D printed scaffolds have pores with a precise and regular geometry (0°-90°, 0°-45°-90°-135°, 0°-60°-120°). PU scaffold porosity evidenced values from 55 to 67%, values that belong to the porosity range of the trabecular bone tissue (30-90%). The compressive modulus varied between 2 and 4 MPa, depending on the printed pattern. Biomimetic nanostructured coating was performed on 0-90° 3DP-PU by Ionized Jet Deposition. Coatings had a submicrometric thickness, variable tuning deposition time, nanostructured surface morphology and biomimetic composition. Coating on 3DP-PU promoted cells colonization of the whole porous scaffolds, compared to the controls, where cells concentrated mostly on the outer layers. In conclusion, based on the obtained results, scaffolds with different geometries have been successfully produced. Morphological and structural properties of the scaffolds here presented are suitable for mimicking the bone tissue, in order to produce a 3D in vitro model useful for bone pathologies research

Among the advanced technology developed and tested for orthopaedic surgery, the Rizzoli (IOR) has a long experience on custom-made design and implant of devices for joint and bone replacements. This follows the recent advancements in additive manufacturing, which now allows to obtain products also in metal alloy by deposition of material layer-by-layer according to a digital model. The process starts from medical image, goes through anatomical modelling, prosthesis design, prototyping, and final production in 3D printers and in case post-production. These devices have demonstrated already to be accurate enough to address properly the specific needs and conditions of the patient and of his/her physician. These guarantee also minimum removal of the tissues, partial replacements, no size related issues, minimal invasiveness, limited instrumentation. The thorough preparation of the treatment results also in a considerable shortening of the surgical and of recovery time. The necessary additional efforts and costs of custom-made implants seem to be well balanced by these advantages and savings, which shall include the lower failures and revision surgery rates. This also allows thoughtful optimization of the component-to-bone interfaces, by advanced lattice structures, with topologies mimicking the trabecular bone, possibly to promote osteointegration and to prevent infection. IOR's experience comprises all sub-disciplines and anatomical areas, here mentioned in historical order. Originally, several systems of Patient-Specific instrumentation have been exploited in total knee and total ankle replacements. A few massive osteoarticular reconstructions in the shank and foot for severe bone fractures were performed, starting from mirroring the contralateral area. Something very similar was performed also for pelvic surgery in the Oncology department, where massive skeletal reconstructions for bone tumours are necessary. To this aim, in addition to the standard anatomical modelling, prosthesis design, technical/technological refinements, and manufacturing, surgical guides for the correct execution of the osteotomies are also designed and 3D printed. Another original experience is about en-block replacement of vertebral bodies for severe bone loss, in particular for tumours. In this project, technological and biological aspects have also been addressed, to enhance osteointegration and to diminish the risk of infection. In our series there is also a case of successful custom reconstruction of the anterior chest wall. Initial experiences are in progress also for shoulder and elbow surgery, in particular for pre-op planning and surgical guide design in complex re-alignment osteotomies for severe bone deformities. Also in complex flat-foot deformities, in preparation of surgical corrections, 3D digital reconstruction and 3D printing in cheap ABS filaments have been valuable, for indication, planning of surgery and patient communication; with special materials mimicking bone strength, these 3D physical models are precious also for training and preparation of the surgery. In Paediatric surgery severe multi planar & multifocal deformities in children are addressed with personalized pre-op planning and custom cutting-guides for the necessary osteotomies, most of which require custom allografts. A number of complex hip revision surgeries have been performed, where 3D reconstruction for possible final solutions with exact implants on the remaining bone were developed. Elective surgery has been addressed as well, in particular the customization of an original total ankle replacement designed at IOR. Also a novel system with a high-tibial-osteotomy, including a custom cutting jig and the fixation plate was tested. An initial experience for the design and test of custom ankle & foot orthotics is also in progress, starting with 3D surface scanning of the shank and foot including the plantar aspect. Clearly, for achieving these results, multi-disciplinary teams have been formed, including physicians, radiologists, bioengineers and technologists, working together for the same goal

Scaffold-based bone tissue engineering holds great promise for the future of osseous defects therapies. Prepare the suitable scaffold properties are physiochemical modifications in terms of porosity, mechanical strength, cell adhesion, biocompatibility, cell proliferation, mineralization and osteogenic differentiation are required. We produce various bone tissue scaffolds with different techniques such as lyophilization, 3D printing and electrospinning. We wish to overview all the different novel scaffold methods and materials. To improve scaffolds poor mechanical properties, while preserving the porous structure, it is possible to coat the scaffold with synthetic or natural polymers. An increasing interest in developing materials in bone tissue engineering is directed to the organic/inorganic composites that mimic natural bone. Specifically, bone tissue is a composite of an organic and inorganic matrix. Using PLLA, loofah, chitin and cellulose biomaterials we produced bone tissue scaffold with lyophilization technique. Also, using fish scale powder and wet electrospun Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) a sponge structure had created. Using MRI image data and 3D printer method, a bone tissue scaffold is created by PLA filament. Their mechanical properties had analysed with compression tests and their biocompatibilities had investigated. In order to provide novel strategies for future treatment of bone tumours, the properties of the scaffold, including its in vitro extended-release properties, the inhibition effects of chemotherapeutic agent on the bone tumours and its bone repair capacities were investigated in vitro by using MG63 cells. To develop chemotherapeutic agent-encapsulated poly(lactic-co-glycolic acid) (PLGA) nanoparticles in a porous nano-hydroxyapatite scaffold we aimed to use double emulsion method

Osteoid osteoma is a classically described benign bone tumour. Traditionally, the surgical treatment of choice was excision, but this can have significant morbidity. In recent years, percutaneous Radiofrequency Ablation (RFA) has grown in popularity as an alternative treatment. This study reports the outcomes using this technique in our regional bone tumour unit. Between May 2003 and October 2007, 14 patients (female, n=4; male, n = 10) aged 15 - 32yrs (mean age, 20.4yrs) underwent CT guided radiofrequency ablation treatment. These patients had typical radiograph, CT, MRI or isotope bone scan features of osteoid osteoma and had significant pain symptoms. The protocol for ablation in our institute is heating the tip of the electrode to 90°C for 6 minutes. All patients were subsequently offered follow up in the out-patient clinic. Outcomes were taken from the Scottish Bone Tumour Registry database. 11 patients (78.6%) patients had complete resolution of symptoms after one RF treatment. 3 (21.4%) cases were unsuccessful but 1 of these was due to technical failure. All 3 of the above patients had complete relief of symptoms after one further RF treatment. 1 (7.1%) patient initially had complete relief of symptoms, but suffered a recurrence after 9 months. This patient also had a second curative treatment. Follow up ranged from 3 – 18 months (mean 10 months). Percutaneous RFA for osteoid osteoma is an attractive treatment due to its efficacy and low morbidity. Our results showed a primary success rate of 78%, a secondary success rate of 100% (after one additional procedure) and a recurrence rate of 7.1%. These are comparable to previous reported series. We believe our results add to the growing literature supporting radiofrequency ablation as the treatment of choice for osteoid osteoma

The aim of this project is to test the parameters of Patient Specific Instruments (PSIs) and measuring accuracy of surgical cuts using sawblades with different depths of PSI cutting guide slot. Clear operative oncological margins are the main target in malignant bone tumour resections. Novel techniques like patient specific instruments (PSIs) are becoming more popular in orthopaedic oncology surgeries and arthroplasty in general with studies suggesting improved accuracy and reduced operating time using PSIs compared to conventional techniques and computer assisted surgery. Improved accuracy would allow preservation of more natural bone of patients with smaller tumour margin. Novel low-cost technology improving accuracy of surgical cuts, would facilitate highly delicate surgeries such as Joint Preserving Surgery (JPS) that improves quality of life for patients by preserving the tibial plateau and muscle attachments around the knee whilst removing bone tumours with adequate tumour margins. There are no universal guidelines on PSI designs and there are no studies showing how specific design of PSIs would affect accuracy of the surgical cuts. We hypothesised if an increased depth of the cutting slot guide for sawblades on the PSI would improve accuracy of cuts. A pilot drybone experiment was set up, testing 3 different designs of a PSI with changing cutting slot depth, simulating removal of a tumour on the proximal tibia. A handheld 3D scanner (Artec Spider, Luxembourg) was used to scan tibia drybones and Computer Aided Design (CAD) software was used to simulate osteosarcoma position and plan intentioned cuts. PSI were designed accordingly to allow sufficient tumour. The only change for the 3 designs is the cutting slot depth (10mm, 15mm & 20mm). 7 orthopaedic surgeons were recruited to participate and perform JPS on the drybones using each design 2 times. Each fragment was then scanned with the 3D scanner and were then matched onto the reference tibia with customized software to calculate how each cut (inferior-superior-vertical) deviated from plan in millimetres and degrees. In order to tackle PSI placement error, a dedicated 3D-printed mould was used. Comparing actual cuts to planned cuts, changing the height of the cutting slot guide on the designed PSI did not deviate accuracy enough to interfere with a tumour resection margin set to maximum 10mm. We have obtained very accurate cuts with the mean deviations(error) for the 3 different designs were: [10mm slot: 0.76 ± 0.52mm, 2.37 ± 1.26°], [15 mm slot: 0.43 ± 0.40 mm, 1.89 ± 1.04°] and [20 mm: 0.74 ± 0.65 mm, 2.40 ± 1.78°] respectively, with no significant difference between mean error for each design overall, but the inferior cuts deviation in mm did show to be more precise with 15 mm cutting slot (p<0.05). Simulating a cut to resect an osteosarcoma, none of the proposed designs introduced error that would interfere with the tumour margin set. Though 15mm showed increased precision on only one parameter, we concluded that 10mm cutting slot would be sufficient for the accuracy needed for this specific surgical intervention. Future work would include comparing PSI slot depth with position of knee implants after arthroplasty, and how optimisation of other design parameters of PSIs can continue to improve accuracy of orthopaedic surgery and allow increase of bone and joint preservation

Most lumps found in the extremity are benign. Some, however, are not. An approach to tertiary referral is required to accommodate the need for specialist evaluation of all concerning lumps, while maintaining an acceptable time to diagnosis and definitive management. We describe a new approach to tertiary sarcoma service, utilising modern communication technology and the “virtual clinic” approach. Methods. Data from 1053 consecutive patients referred to the MSK oncology service at Glasgow Royal Infirmary between January 2010 and August 2012 was prospectively collected. Results. All suspected musculoskeletal sarcoma cases were discussed referred to our tertiary sarcoma virtual clinic were discussed. Mean time from referral to clinic for the 625 patents referred from January 2011 was 5.1 days. 41% of referrals came from out-with our health trust. 28.3% of patients were discharged from the virtual clinic without need for physical appointment. 45.8% were sent for further investigation prior to first clinic appointment, with the remaining 25.5% given an urgent clinic appointment. Final diagnoses of soft tissue tumours, bone tumours and “tumour like conditions” were present in almost equal parts. 358 patients (34%) of patients went on to have surgery, with 59 malignant soft tissue and 53 malignant bone tumours over this time period. Conclusions. Through an early, virtual clinic approach to tertiary sarcoma care, a third of referrals have been managed quickly without the need for an unnecessary appointment for the patient. For a further 45% of patients the first appointment will be after all necessary investigations have been performed to facilitate rapid decision making. This enables shorter clinic waiting times and rapid transition from first referral to definitive management

We evaluated the possible induction of a systemic immune response to increase anti-tumour activity by the re-implantation of destructive tumour tissue treated by liquid nitrogen in a murine osteosarcoma (LM8) model. The tumours were randomised to treatment by excision alone or by cryotreatment after excision. Tissue from the tumour was frozen in liquid nitrogen, thawed in distilled water and then re-implanted in the same animal. In addition, some mice received an immunological response modifier of OK-432 after treatment. We measured the levels of interferon-gamma and interleukin-12 cytokines and the cytotoxicity activity of splenocytes against murine LM8 osteosarcoma cells. The number of lung and the size of abdominal metastases were also measured. Re-implantation of tumour tissue after cryotreatment activated immune responses and inhibited metastatic tumour growth. OK-432 synergistically enhanced the anti-tumour effect. Our results suggest that the treatment of malignant bone tumours by reconstruction using autografts containing tumours which have been treated by liquid nitrogen may be of clinical value

Bone tumours may recur locally even after wide surgical excision and systemic chemotherapy. Local control of growth may be accomplished by the addition of cytostatic drugs such as methotrexate (MTX) to bone cement used to fill the defect after surgery and to stabilise the reconstructive prosthesis. We have studied the elution kinetics of MTX and its solvent N-methyl-pyrrolidone (NMP) from bone cement and their biological activities in five cell lines of osteosarcoma and in osteoblasts, and compared them with the effects of the parent compounds alone and in combination. Our findings show that MTX is released continuously over months at concentrations highly cytotoxic to osteosarcoma cells and suggest that the impregnated bone cement would be effective in the long term. Proliferating osteoblasts, however, were much less sensitive towards MTX. The dose-response relationship for NMP and experiments with MTX/NMP-mixtures show that the eluted concentrations of solvent are not toxic and do not influence the effects of MTX. We suggest that bone cement containing MTX dissolved in NMP releases the drug in a suitable and effective way and may be of value in the treatment of bone tumours

Systemic metal ion monitoring (Co;Cr) has proven to be a useful screening tool for implant performance to detect failure at an early stage in metal-on-metal hip arthroplasty. Several clinical studies have reported elevated metal ion levels after total knee arthroplasty (TKA), with fairly high levels associated with rotating hinge knees (RHK) and megaprostheses. 1. In a knee simulator study, Kretzer. 2. , demonstrated volumetric wear and corrosion of metallic surfaces. However, prospective in vivo data are scarce, resulting in a lack of knowledge of how levels evolve over time. The goal of this study was to measure serum Co and Cr levels in several types TKA patients prospectively, evaluate the evolution in time and investigate whether elevated levels could be used as an indicator for implant failure. The study was conducted at Ghent University hospital. 130 patients undergoing knee arthroplasty were included in the study, 35 patients were lost due to logistic problems. 95 patients with 124 knee prostheses had received either a TKA (primary or revision) (69 in 55 patients), a unicompartimental knee arthroplasty (7 UKA), a RHK (revision −7 in 6 patients) or a megaprosthesis (malignant bone tumours − 28 in 27 patients). The TKA, UKA and RHK groups were followed prospectively, with serum Co and Cr ions measured preoperatively, at 3,6 and 12 months postoperatively. In patients with a megaprosthesis, metal ions were measured at follow-up (cross-sectional study design). In primary knees, we did not observe an increase in serum metal ion levels at 3, 6 or 12 months. Two patients with a hip arthroplasty had elevated preTKA Co and Cr levels. There was no difference between unilateral and bilateral knee prostheses. In the revision group, elevated pre-revision levels were found in 2 failures for implant loosening. In both cases, ion levels decreased postoperatively. In revisions with a standard TKA, there was no significant increase in metal ions compared to primary knee arthroplasty. RHK were associated with a significant increase in Co levels even at short-term (3–12 months). The megaprosthesis group had the highest metal ion levels and showed a significant increase in Co and Cr with time in patients followed prospectively. With the current data, we could not demonstrate a correlation between metal ion levels, size of the implant or length of time in situ. In primary knee arthroplasty with a standard TKA or UKA, metal ion levels were not elevated till one year postoperatively. This suggests a different mechanism of metal ion release in comparison to metal-on-metal hip arthroplasties. In two cases of revision for implant loosening, pre-revision levels were elevated, possibly associated with component wear, and decreased after revision. With RHK, slightly elevated ion levels were found prospectively. Megaprostheses had significantly elevated Co and Cr levels, due to corrosion of large metallic surfaces and/or wear of components which were not perfectly aligned during difficult reconstruction after tumour resection. Further research is needed to assess the clinical relevance of metal ion levels in knee arthroplasty

Metastatic osteosarcoma is seen in 10-20% of patients at initial presentation with the lung the most common site of metastasis. Historically, prognosis has been poor. We studied trends in survival in our small developed nation and aimed to identify correlations between the survival rate and three factors: newer chemotherapy, advances in radiological imaging and a more aggressive approach adopted by cardiothoracic surgeons for lung metastases. Our national bone tumour registry was used to identify patients at the age of 18 or under, who presented with metastatic disease at initial diagnosis between 1933 and 2006. There were 30 patients identified. Kaplan-Meier analysis was used to determine survival rates and univariate analysis was performed using the Cox regression proportional hazards model. Median survival has improved over the last 50 years; highlighted by the ‘Kotz’ eras demonstrating incremental improvement with more effective chemotherapy agents (p=0.004), and a current 5-year survival of 16%. Aggressive primary and metastatic surgery also show improving trends in survival. Three patients have survived beyond 5 years. The introduction of computerised tomography scanning has led to an increase in the prevalence of metastases at initial diagnosis. Metastatic osteosarcoma remains with a very poor prognostic factor, however, aggressive management has been shown to prolong survival

Introduction. Hand tumors are usually rare and there is not much literature about series of cases. We have studied a series of 110 cases. Hand tumors do consists of both benign and malignant cases. Methods. We studied series of 110 cases at Karnataka Institute of Medical Sciences, Hubli and Mysore Medical College & Research Institute, Mysore. We retrospectively reviewed the records of 110 patients who underwent double ray amputations at our center over few years: few had amputations of the fourth and fifth rays and others amputation of the second and third rays. Mean age at surgery was 34 years (range, 10–45 years), and minimum follow up was 64 months (mean, 98 months; range, 64–136 months). Some patients had high-grade soft tissue sarcomas of the hand, synovial sarcomas, malignant peripheral nerve sheath tumors, and undifferentiated sarcoma. No patients had detectable metastases at surgery. Results. All patients were completely disease-free at latest follow up. One patient was alive with lung metastases detected 32 months after surgery. No patients developed local tumor recurrence. Functional assessment showed a mean Musculoskeletal Tumor Society score of 24 (range, 19–28) and mean grip strength 24% of the contra lateral side (range, 17%–35%). Conclusions. The majority of osseous tumors of the hand are benign. The surgeon who evaluates and treats osseous tumors of the hand has to be familiar with limb anatomy, tumor biology, various presentations of the tumors and the range of treatment possibilities and their limitations. Lesions in the hand more often present earlier in their course than those at other sites, just because they are more likely to superficial and easily noticed. Ganglion cyst is the most frequently encountered comprising 50–70% of benign tumors of hand. Enchondroma was the next common benign bone tumour followed by osteoid osteoma, osteoblastoma, aneurismal bone cyst, giant cell tumor, epidermoid cyst, and osteochondroma. Although malignant neoplasms in the hand that arise from tissues other than the skin are very rare, the hand may be the site of distant breast, lung, kidney, esophagus, or colon adenocarcinoma metastases, most of which have a predilection for the distal phalanges. Malignant tumours of the hand are rare, although there remain many instances in which marginal excisions are performed for unsuspected malignant hand lesions. Suboptimal biopsy incisions and inadvertent contamination during these excisions may result in larger resections or amputations being necessary to ensure complete removal of the tumour with negative margins