Aims. Malignancy and surgery are risk factors for venous thromboembolism (VTE). We undertook a systematic review of the literature concerning the prophylactic management of VTE in orthopaedic oncology patients. Methods. MEDLINE (PubMed), EMBASE (Ovid), Cochrane, and CINAHL databases were searched focusing on VTE, deep vein thrombosis (DVT), pulmonary embolism (PE), bleeding, or wound complication rates. Results. In all, 17 studies published from 1998 to 2018 met the inclusion criteria for the systematic review. The mean incidence of all VTE events in orthopaedic oncology patients was 10.7% (1.1% to 27.7%). The rate of PE was 2.4% (0.1% to 10.6%) while the rate of lethal PE was 0.6% (0.0% to 4.3%). The overall rate of DVT was 8.8% (1.1% to 22.3%) and the rate of symptomatic DVT was 2.9% (0.0% to 6.2%). From the studies that screened all patients prior to hospital discharge, the rate of asymptomatic DVT was 10.9% (2.0% to 20.2%). The most common risk factors identified for VTE were endoprosthetic replacements, hip and pelvic resections, presence of metastases, surgical procedures taking longer than three hours, and patients having chemotherapy. Mean incidence of VTE with and without chemical prophylaxis was 7.9% (1.1% to 21.8%) and 8.7% (2.0% to 23.4%; p = 0.11), respectively. No difference in the incidence of bleeding or wound complications between prophylaxis groups was reported. Conclusion. Current evidence is limited to guide clinicians. It is our consensus opinion, based upon logic and deduction, that all patients be considered for both mechanical and chemical VTE prophylaxis, particularly in high-risk patients (pelvic or hip resections, prosthetic reconstruction, malignant diagnosis, presence of metastases, or surgical procedures longer than three hours). Additionally, the surgeon must determine, in each patient, if the risk of haemorrhage outweighs the risk of VTE. No individual pharmacological agent has been identified as being superior in the prevention of VTE events. Cite this article: Bone Joint J 2020;102-B(12)1743:–1751

Chondrosarcoma is the second most common surgically treated primary bone sarcoma. Despite a large number of scientific papers in the literature, there is still significant controversy about diagnostics, treatment of the primary tumour, subtypes, and complications. Therefore, consensus on its day-to-day treatment decisions is needed. In January 2024, the Birmingham Orthopaedic Oncology Meeting (BOOM) attempted to gain global consensus from 300 delegates from over 50 countries. The meeting focused on these critical areas and aimed to generate consensus statements based on evidence amalgamation and expert opinion from diverse geographical regions. In parallel, periprosthetic joint infection (PJI) in oncological reconstructions poses unique challenges due to factors such as adjuvant treatments, large exposures, and the complexity of surgery. The meeting debated two-stage revisions, antibiotic prophylaxis, managing acute PJI in patients undergoing chemotherapy, and defining the best strategies for wound management and allograft reconstruction. The objectives of the meeting extended beyond resolving immediate controversies. It sought to foster global collaboration among specialists attending the meeting, and to encourage future research projects to address unsolved dilemmas. By highlighting areas of disagreement and promoting collaborative research endeavours, this initiative aims to enhance treatment standards and potentially improve outcomes for patients globally. This paper sets out some of the controversies and questions that were debated in the meeting. Cite this article: Bone Joint J 2024;106-B(5):425–429

Objectives. As tumours of bone and soft tissue are rare, multicentre prospective collaboration is essential for meaningful research and evidence-based advances in patient care. The aim of this study was to identify barriers and facilitators encountered in large-scale collaborative research by orthopaedic oncological surgeons involved or interested in prospective multicentre collaboration. Methods. All surgeons who were involved, or had expressed an interest, in the ongoing Prophylactic Antibiotic Regimens in Tumour Surgery (PARITY) trial were invited to participate in a focus group to discuss their experiences with collaborative research in this area. The discussion was digitally recorded, transcribed and anonymised. The transcript was analysed qualitatively, using an analytic approach which aims to organise the data in the language of the participants with little theoretical interpretation. Results. The 13 surgeons who participated in the discussion represented orthopaedic oncology practices from seven countries (Argentina, Brazil, Italy, Spain, Denmark, United States and Canada). Four categories and associated themes emerged from the discussion: the need for collaboration in the field of orthopaedic oncology due to the rarity of the tumours and the need for high level evidence to guide treatment; motivational factors for participating in collaborative research including establishing proof of principle, learning opportunity, answering a relevant research question and being part of a collaborative research community; barriers to participation including funding, personal barriers, institutional barriers, trial barriers, and administrative barriers and facilitators for participation including institutional facilitators, leadership, authorship, trial set-up, and the support of centralised study coordination. Conclusions. Orthopaedic surgeons involved in an ongoing international randomised controlled trial (RCT) were motivated by many factors to participate. There were a number of barriers to and facilitators for their participation. There was a collective sense of fatigue experienced in overcoming these barriers, which was mirrored by a strong collective sense of the importance of, and need for, collaborative research in this field. The experiences were described as essential educational first steps to advance collaborative studies in this area. Knowledge gained from this study will inform the development of future large-scale collaborative research projects in orthopaedic oncology. Cite this article: J. S. Rendon, M. Swinton, N. Bernthal, M. Boffano, T. Damron, N. Evaniew, P. Ferguson, M. Galli Serra, W. Hettwer, P. McKay, B. Miller, L. Nystrom, W. Parizzia, P. Schneider, A. Spiguel, R. Vélez, K. Weiss, J. P. Zumárraga, M. Ghert. Barriers and facilitators experienced in collaborative prospective research in orthopaedic oncology: A qualitative study. Bone Joint Res 2017;6:–314. DOI: 10.1302/2046-3758.65.BJR-2016-0192.R1

The recently published Prophylactic Antibiotic Regimens In Tumor Surgery (PARITY) trial found no benefit in extending antibiotic prophylaxis from 24 hours to five days after endoprosthetic reconstruction for lower limb bone tumours. PARITY is the first randomized controlled trial in orthopaedic oncology and is a huge step forward in understanding antibiotic prophylaxis. However, significant gaps remain, including questions around antibiotic choice, particularly in the UK, where cephalosporins are avoided due to concerns of Clostridioides difficile infection. We present a review of the evidence for antibiotic choice, dosing, and timing, and a brief description of PARITY, its implication for practice, and the remaining gaps in our understanding. Cite this article: Bone Joint J 2023;105-B(8):850–856

Musculoskeletal tumours are relatively rare and as such, they are not well known by the population and by general practicioners. We observed that an important proportion of our patients has seen major delays at diferent stages of their referral pathway. It is well recognised that such delays can cause avoidable loss of function, local and systemic recurrence and increase in health system costs. The main objective of this study was to prospectively assess the referral paterns of our patients to pinpoint the causes of the delays. This should allow the formation of strategies to minimise delas and their impact. The secondary objective was to assess the performance of our centre in comparaison to other centre with the goal of improving quality of care. Prospective follow up data is available for 457 patient referred to our musculoskeletal oncology team between july 2011 and november 2014. Every patients filled questionnaires on their initial referral patterns. Site specific function and quality of life are evaluated at baseline and at subsequent follow-up (six months, one year, three years and five years). The average delay between the first symptoms and the first medical consultation with a general practitioner was 37 weeks (CI: 27–46). The average delay between the first medical consultation and the referral to orthopaedic oncology was 54 weeks (CI: 43–65). The delay between the first consultation with a general practitioner and the first radiologic test was 31 weeks (CI: 22–39). The delay between the first radiologic test and the referral to orthopaedic oncology was 28 weeks (CI 24–32). The delay between the referral to orthopaedic oncology and the first appointment to our centre was three weeks (CI 2–4). Before the referral to our center, 23% of the patients met two general practitioners and 10% met with 3 or more general practitioner. Fifty-two pervent of the patients had a consultation with a specialist and 19% saw two or more specialists. It is imperative to raise awareness of musculoskeletal tumours and indication for early referral in general practitioners. One of the main problems in our actual referral patern is early access to appropriate imaging. The creation of a referral program with specific guidelines is, in our opinion, the best way to significantly reduce the delays for appropriate management of patients with suspiscion of musculoskeletal tumours

Purpose. The consequences of infection in orthopedic oncology patients are well known. Methicillin sensitive- and resistant Staphylococcus aureus (MSSA and MRSA, respectively) are common infecting organisms which may colonize patients pre-operatively. The prevalence of colonization in orthopedic oncology patients is unknown. We sought to prospectively establish the prevalence of MSSA and MRSA colonization in an orthopedic oncology patient population. Method. Beginning in September 2009, all oncology patients of a single surgical service were prospectively screened pre-operatively for MSSA and MRSA colonization using PCR nasal swabs as part of an infection control protocol. Patients identified as carriers underwent decolonization treatment peri-operatively. Results. One hundred thirty-nine oncology patients underwent 143 independent procedures with orthopedics as the primary service from September 1, 2009 August 31, 2010. MSSA/MRSA screening capture rate was 93%. Prevalence of MSSA colonization was 22% and MRSA colonization was 3.8%. MSSA colonization was not associated with malignant diagnosis (p=1.0), or recent chemo- or radiotherapy treatment (p>0.50 for both). All MRSA colonized patients had undergone inpatient oncology treatment or had occupational exposure to MRSA in the last year. Post-operative infection developed in 4/124 patients with type I surgical incisions (3.2%). Infecting organisms were coagulase negative Staphylococcus (n=2), MSSA (n=1), and Streptococcus (n=1). Conclusion. MSSA colonization rates in orthopedic oncology patients are similar to reported population values. MRSA colonization rates are low. Patient diagnosis or adjuvant treatments do not appear to influence colonization rates. MRSA colonization was only seen in patients with inpatient or occupational exposure to MRSA

Aims. Most patients with advanced malignancy suffer bone metastases, which pose a significant challenge to orthopaedic services and burden to the health economy. This study aimed to assess adherence to the British Orthopaedic Oncology Society (BOOS)/British Orthopaedic Association (BOA) guidelines on patients with metastatic bone disease (MBD) in the UK. Methods. A prospective, multicentre, national collaborative audit was designed and delivered by a trainee-led collaborative group. Data were collected over three months (1 April 2021 to 30 June 2021) for all patients presenting with MBD. A data collection tool allowed investigators at each hospital to compare practice against guidelines. Data were collated and analyzed centrally to quantify compliance from 84 hospitals in the UK for a total of 1,137 patients who were eligible for inclusion. Results. A total of 846 patients with pelvic and appendicular MBD were analyzed, after excluding those with only spinal metastatic disease. A designated MBD lead was not present in 39% of centres (33/84). Adequate radiographs were not performed in 19% of patients (160/846), and 29% (247/846) did not have an up-to-date CT of thorax, abdomen, and pelvis to stage their disease. Compliance was low obtaining an oncological opinion (69%; 584/846) and prognosis estimations (38%; 223/846). Surgery was performed in 38% of patients (319/846), with the rates of up-to-date radiological investigations and oncology input with prognosis below the expected standard. Of the 25% (215/846) presenting with a solitary metastasis, a tertiary opinion from a MBD centre and biopsy was sought in 60% (130/215). Conclusion. Current practice in the UK does not comply with national guidelines, especially regarding investigations prior to surgery and for patients with solitary metastases. This study highlights the need for investment and improvement in care. The recent publication of British Orthopaedic Association Standards for Trauma (BOAST) defines auditable standards to drive these improvements for this vulnerable patient group. Cite this article: Bone Joint J 2023;105-B(10):1115–1122

Given the low prevalence of sarcoma, international cooperation is necessary to recruit sufficient numbers of patients for surgical trials. The PARITY (Prophylactic Antibiotic Regimens in Tumour Surgery) trial is the first international multicentre trial in orthopedic oncology and successfully achieved target enrollment of 600 patients across 12 countries. It is important to reflect upon the challenges encountered and experiences gained to inform future trials. The objective of this study is to describe recruitment patterns and examine the differences in enrollment across different PARITY sites and identify variables associated with varying levels of recruitment. Data from this study was obtained from the PARITY trial Methods Centre and correspondence data. We performed descriptive statistics to demonstrate the recruitment patterns over time. We compared recruitment, time to set up, and time to enroll the first patient between North American and international sites, and sites that had dedicated research personnel. Two-tailed non-paired t-tests were performed to compare average monthly recruitment rates between groups with significance being set at alpha=0.05. A total of 600 patients from 48 clinical sites and 12 countries were recruited from January 2013 through to October 2019. Average monthly enrollment increased every year of the study. There were 36 North American and 12 international sites. North American sites were able to set up significantly faster than international sites (19.3 vs. 28.3 months p=0.037). However, international sites had a significantly higher recruitment rate per month once active (0.2/month vs. 0.62/month, p=0.018). Of active sites, 40 (83%) had research support personnel and 8 (17%) sites did not. Sites with research personnel were able to reach ‘enrolment ready’ status significantly faster than sites without research support (19.6 vs. 30.7 months, p=0.032). However, there was no significant difference in recruitment rate per month once the sites began enrolling (0.28/month vs. 0.2/month, p=0.63). Trial sites that took longer than 1 year to recruit their first patient had 3x lower average recruitment rate compared to sites that were able to recruit their first patient within a year of being enrolment ready. The PARITY trial is the first multicentre RCT in orthopaedic oncology. The PARITY investigators were able to increase the recruitment levels throughout the trial and generally avoid trial fatigue. This was a North American based trial which may explain the longer start up times internationally given the different regulatory bodies associated with drug-related trials. However, international sites should be considered critical as they were able to recruit significantly more patients per month once active. The absence of research support personnel should not preclude a site from inclusion. These sites took longer to setup but had no difference in monthly recruitment once active. This study will create a framework for identifying and targeting high yield sites for future randomized control trials within orthopaedic oncology to maximum recruitment and resource allocation. Data quality is another consideration that will be addressed in future analyses of the PARITY trial

Aims. Due to their radiolucency and favourable mechanical properties, carbon fibre nails may be a preferable alternative to titanium nails for oncology patients. We aim to compare the surgical characteristics and short-term results of patients who underwent intramedullary fixation with either a titanium or carbon fibre nail for pathological long-bone fracture. Methods. This single tertiary-institutional, retrospectively matched case-control study included 72 patients who underwent prophylactic or therapeutic fixation for pathological fracture of the humerus, femur, or tibia with either a titanium (control group, n = 36) or carbon fibre (case group, n = 36) intramedullary nail between 2016 to 2020. Patients were excluded if intramedullary fixation was combined with any other surgical procedure/fixation method. Outcomes included operating time, blood loss, fluoroscopic time, and complications. Fisher’s exact test and Mann-Whitney U test were used for categorical and continuous outcomes, respectively. Results. Patients receiving carbon nails as compared to those receiving titanium nails had higher blood loss (median 150 ml (interquartile range (IQR) 100 to 250) vs 100 ml (IQR 50 to 150); p = 0.042) and longer fluoroscopic time (median 150 seconds (IQR 114 to 182) vs 94 seconds (IQR 58 to 124); p = 0.001). Implant complications occurred in seven patients (19%) in the titanium group versus one patient (3%) in the carbon fibre group (p = 0.055). There were no notable differences between groups with regard to operating time, surgical wound infection, or survival. Conclusion. This pilot study demonstrates a non-inferior surgical and short-term clinical profile supporting further consideration of carbon fibre nails for pathological fracture fixation in orthopaedic oncology patients. Given enhanced accommodation of imaging methods important for oncological surveillance and radiation therapy planning, as well as high tolerances to fatigue stress, carbon fibre implants possess important oncological advantages over titanium implants that merit further prospective investigation. Level of evidence: III, Retrospective study. Cite this article: Bone Jt Open 2022;3(8):648–655

Rates of prosthetic joint infection in megaprostheses are high. The application of silver ion coating to implants serves as a deterrent to infection and biofilm formation. A retrospective review was performed of all silver-coated MUTARS endoprosthetic reconstructions (SC-EPR) by a single Orthopaedic Oncology Surgeon. We examined the rate of component revision due to infection and the rate of infection successfully treated with antibiotic therapy. We reviewed overall revision rates, sub-categorised into the Henderson groupings for endoprosthesis modes of failure (Type 1 soft tissue failure, Type 2 aseptic loosening, Type 3 Structural failure, Type 4 Infection, Type 5 tumour progression). 283 silver-coated MUTARS endoprosthetic reconstructions were performed for 229 patients from October 2012 to July 2022. The average age at time of surgery was 58.9 years and 53% of our cohort were males. 154 (71.3%) patients underwent SC-EPR for oncological reconstruction and 32 (14.8%) for reconstruction for bone loss following prosthetic joint infection(s). Proximal femur SC-EPR (82) and distal femur (90) were the most common procedures. This cohort had an overall revision rate of 21.2% (60/283 cases). Component revisions were most commonly due to Type 4 infection (19 cases), Type 2 aseptic loosening/culture negative disease (15 cases), and Type 1 dislocation/soft tissue (12 cases). Component revision rate for infection was 6.7% (19 cases). 15 underwent exchange of implants and 4 underwent transfemoral amputation due to recalcitrant infection and failure of soft tissue coverage. This equates to a limb salvage rate of 98.3%. The most common causative organisms remain staphylococcus species (47%) and polymicrobial infections (40%). We expand on the existing literature advocating for the use of silver-coated endoprosthetic reconstructions. We provide insights from the vast experience of a single surgeon when addressing patients with oncological and bone loss-related complex reconstruction problems

After 25 years in orthopaedic oncology the author wishes to set a challenge for the next generation by posing 10 questions which he believes still do not have answers and which may improve outcomes for patients with sarcomas. Why are sarcomas diagnosed so late?. Can we ever decide what is a safe margin?. What is the role of neoadjuvant chemotherapy for STS?. What can we do to decrease the risk of infection after limb salvage surgery?. What is the significance of local recurrence on outcome?. What really is the best treatment for Ewing's sarcoma of the pelvis?. Is cross sectional imaging essential as part of patient follow up?. Is it possible to evaluate outcomes combining survival and function?. Why can't we run a surgical trial in orthopaedic oncology?. How can we evaluate surgical success?. The author suggests ways these questions may be answered

Most types of bone tumor surgery require intra-operative imaging or measurement to control margins and prevent unnecessary bone loss. Computer Assisted Surgery (CAS) has been used as a replacement of fluoroscopy or direct measurement tools in four specific types of oncological orthopaedic surgical approaches. There are intralesional treatments, image-based resections, image-based resections with image-based reconstructions and image-based resections with imageless tumor prostheses reconstruction. Since 2006 we have performed 130 oncological surgeries with CAS. Most cases were excochleations, 64, where CAS replaces fluoroscopy as an intra-operative imaging modality. Advantages over fluoroscopy are real time three dimensional feedback, high-res image and no use of ionizing radiation. It is especially useful in larger lesions or lesions located in the femoral head or pelvis. Currently a study is being performed on patient satisfaction, recurrence and complications. Another application where CAS has often been used is in resections and segmental resections (together 45). These can be preplanned before surgery, incorporating the margin required, and checked intra-operatively. Coloration of the tumor, critical structures is useful to avoid these. Sometimes it's possible with careful planning to spare structures that otherwise probably would not confidently have spared. With hemicortical resection (5) it's possible to use CAS to exactly copy the shape of the resected bone to an allograft. A Ct scan of one case shows an average gap between host and graft of 0.9 mm (range 0–5.4) along the 6 cm resection. Finally in 16 cases of imageless use in placement of tumor prostheses it feels greatly helpful in reconstructing the joint line, length and correct rotation. There were 8 failures in these 130 cases with the system or software. Setup time was measured in 47 cases and was on average 6:50 (range 2:26–14:27). Indication and performance of CAS in orthopedic oncology is an under researched aspect of CAS. In our opinion CAS shows great promise in the field of orthopedic oncology and is a valuable tool in the operating room

Quality outcomes from medical intervention are assumed by patients & the community. However such quality cannot be assured in every case. There are systems which can be developed which will make the safety of patients more assured. In any system of medical care, it is presumed that the practitioners who are taking care of the patient are qualified both in their basic qualification & also in their higher qualification. As well it is now accepted that appropriate credentialling occurs & that this is the purview of the hospital which will check the qualifications & currency of practice with the medical board & the higher degree & currency (participation in CPD) with the College concerned. They should also review the privileges which define the scope of practice. In orthopaedic oncology it is now essential that a practitioner has completed a higher form of training such as a Fellowship. At the current time in this country there is no process of assurance of the quality of the education program but there is continuing development in this area. Peer review & audit remains problematic. The RACS demands that surgeons participate in an appropriate audit process yearly & that this reviews outcomes rather than just complications. The participation is however voluntary. Despite this, the participation rate is greater than 94% of all surgeons. Medical boards have been requested to make participation in a quality CPD program compulsory, but have not done so, & there are no sanctions for non participation – yet. Most surgeons participate in regular morbidity & mortality meetings, but these are not truly audits of outcome. It would be wise for the Australian Sarcoma Group to develop outcome measures which could easily be collected. The desire to perform research should not be confused with audit which simply addresses quality at an appropriate expert level and which the community expects. Prospective collection & review of outcome measures will mean that trends in performance will be noted earlier. This is particularly important in adverse events. These processes have been embraced by some branches of surgery more than others. Medical outcome reviews of performance have not been developed to such an extent in most disciplines for a variety of reasons, including the fact that surgical endpoints can be more easily identified. The same principles apply, however. It is important for the profession to participate in self audit or third parties will demand it, not necessarily in a way which we might prefer

Aim. was to analyze infections after bone tumour surgery. Method. 1463 patients treated from 1976 to 2007 were analized: 1036 with resection and prostheses in the lower limbs, 344 with resection and prostheses in the upper limbs, 83 with surgery for sacral tumours. Infections were analyzed for time of occurrence (“postoperative” in the first 4 weeks from surgery, “early” within 6 months, and “late” after 6 months), microbic agents, treatment, outcome. Results. In lower limbs, infections occurred in 80 cases (7.7%): generally monomicrobial, caused by gram positives, postoperative in 9, early in 12, late in 59 cases. Treatment was “two stage” in 73, “one stage” in 4, primary amputation in 3. Revisions for infection were successful in 63 patients (79%), while 17 patients were amputated (21%). In upper limbs, infections occurred in 20 cases (5.8%): generally monomicrobial, caused by gram positives (88.5%), postoperative in 2 cases, early in 7, late in 11. “Two stage” treatment was attempted in all cases, but only in 3 prosthesis was re-implanted, since the cement spacer yelded similar function. No infections were observed in 28 intralesional excisions of sacral giant cell tumours. Infection occurred in 23/52 resected sacral tumours (44%) (Three patients died postoperatively were excluded from this group): postoperative in 16 cases and early in 7, caused by gram negatives in 62% and multimicrobial in 74%. Surgical debridements associated with antibiotic therapy according to coltures cured infection in all cases. Conclusion. Infection is a severe complication in orthopedic oncology. Its incidence in the extremities (7.7% and 5.8%) is lower than after sacral surgery (44%). It is influenced by chemotherapy and by the presence of foreign bodies. Infections were mostly late, monomicrobial, gram positive in extremities, while early, multimicrobial and gram negative in sacral surgery

In orthopaedic oncology surgical precision is important and intraoperative imaging is often necessary. CAS may enhance precision and provide continuous 3D imaging without radiation. The goal of this work is to report our experience with CAS. Since 2006 we used CAS (Stryker) in 26 patients with a bone tumour: 11 chondrosarcomas, three osteosarcomas, seven osteochondromas and five miscellaneous. Twelve lesions were located in the femur, six in the pelvis, five in the lower leg and three in the upper extremity. In 18 cases a tumour was excised, in six of these a prosthesis was placed. In eight cases a curettage was done. In 23 cases the navigation was image-based (CT and/or MRI based) and in three cases image-less (no image-preparation necessary preoperatively). CAS was successfully employed in 23 cases. In three cases the procedure was aborted. In two cases, both in the ulna, we were unable to reconstruct the exact dimensions and in one case (image-less) the tracker was to far away from the work-field. There were no complications related to CAS. Mean precision is 0.5 mm. The time CAS takes is about 15 minutes during the procedure (7–60). In the eight curettages it proved helpful. We did not measure radiation time. In the six resections were tumour-prostheses were placed it was really helpful in rotation and length determination. In three of these, image-less navigation was performed (all distal femur). In osteochondroma resections it is helpful in four of seven cases. All surgical margins were adequate in the resections; after curettage, all MRI controls at three months did not show residual tumour. Oncology follow-up is too short yet; there was one local recurrence after two years in a parosteal osteosarcoma. We conclude that CAS can be our navigator in orthopaedic oncology; it is successful in providing precision and continuous 3D imaging. The indication area needs further study

To assess the performance of calcium sulphate pellets as a bone graft substitute in an Orthopaedic Oncology practice using clinical and radiological outcomes. Between 1998 and 2001, calcium sulphate pellets were used in cavitary defects in 38 procedures in 34 patients with bone tumours. In 29 calcium sulphate pellets were used alone, in 8 allograft and in 1 autograft bone was added. The diagnosis was unicameral bone cyst in 13, giant cell tumour in 11, non-ossifying fibroma in 2, chondroblastoma in 2, benign fibrous histiocytoma in 2 and another pathology in 8 procedures. The femur was involved in 12 procedures, the humerus in 8, the radius in 5, the tibia in 4, the fibula in 3, the calcaneus in 2, and one procedure each in the tarsal cuboid, a metatarsal, the talus, and the middle phalanx of a finger. Median follow up was 14 months (3 to 48). Seven patients had wound complications. Pellets had absorbed completely in 26/28 (93%) evaluable procedures by 3 months. Healing of the defect occurred in 24/28 (86%) evaluable procedures by 6 months. In 6 cases, the healed defect contained cystic areas simulating local recurrence. In 3 cases, there was collapse of the defect. In cavitary defects, calcium sulphate pellets reliably absorb. Some patients have wound complications, especially where the cavity is relatively superficial. The pellets do not provide mechanical stability where there is attenuated cortical bone. Cysts within the healed defect may simulate recurrence

Aims: To establish the frequency and demographics of soft tissue sarcomas (STS) presenting in the lower limb. Methods: Patients presenting to a tertiary referral orthopaedic oncology unit over a 10-year period were prospectively entered into a computerised database. The site of primary STS and demographic details were also recorded. Results: 1519 STS in all body regions were treated. 1067 (70.2%) within the lower limb. 57.0% thigh, 13.0% calf, 8.2% foot and ankle, 7.7% buttock, 5.7% knee, 4.6% pelvis and 3.8% in the groin. There was a male predominance (56.2%). M:F ratio was 2.5:1 for the groin and 1.3:1 for the thigh with the other body regions approximately equal. Conclusion: The majority of STS are found in the lower limb. In this large series there was a male predominance most marked in groin presentations

Introduction. 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. Methods. 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 (figure 1). 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 (figure 1). 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 (figure 3). In order to tackle PSI placement error, a dedicated 3D-printed mould was used. Results. 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°], [15mm slot: 0.43±0.40mm, 1.89±1.04°] and [20mm: 0.74±0.65mm, 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 15mm cutting slot (p<0.05) (figure 2). Discussion. 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. For figures/tables, please contact authors directly.

Current survival rates for cancer in the UK are perceived to be worse than those in mainland Europe. In order to asses this we investigated the prognostic value of patient and treatment parameters in the management of osteosarcoma, and whether these parameters are equally important across international boundaries. Retrospective, cross-sectional study of patients (n=428) diagnosed with non metastatic distal femur or proximal tibia osteosarcoma, between 1990–1997 at two specialist orthopaedic oncology centres; Birmingham, UK and Bologna, Italy. Disease free survival (DFS) and overall survival (OS) were assessed by Kaplan-Meier, Fisher’s PLSD and Cox proportional hazard regression. Results : DFS and OS were 43% and 60% at 5 years in Centre 1 and 56% and 73% at Centre 2 respectively. Median survival was 108 weeks at Centre 1 and 136 weeks at Centre 2. A significant difference in DFS and OS was demonstrated between the centres (p=0. 0019 and p=0. 0280 respectively). The most important prognosticators were raised alkaline phosphatase (p=0. 002 and p=0. 0019), degree of chemotherapy induced necrosis (p=0. 0001 and p=0. 0002) and tumour volume > 150cm³ (p=0. 0037 and p=0. 0057). The most significant combination of prognosticators was alkaline phosphatase and tumour necrosis. 75% of patients in centre 2 had a good chemotherapy response (> 90% necrosis) compared to only 29% in Centre 1. The other prognostic indicators were evenly matched. Chemotherapy regime was found to have significantly different outcome in DFS and OS. This is a retrospective study designed to explore possible reasons for differences in survival between two international centres. It would appear that all known patient factors were matched between the centres but that the main difference was in the effectiveness of chemotherapy. Further international prospective studies are needed to confirm these findings

Radio Frequency Ablation (RFA) is a precise CT-guided technique to generate a small pre-defined field of dissecated tissue. Its’ present use in orthopaedic oncology is to treat osteoid osteoma. We have also treated other lesions with RFA and want to report our present indications and complications. From 2005 to 2008 we performed 30 procedures: 23 osteoid osteomas, five low-grade chondrosarcomas, one chondroblastoma and one thyroid metastasis. Localisations were femur in 14 cases, tibia in 10, calcaneus in two, fibula in two, sacrum in one and scapula in one. All patients were treated with CT- guided RFA (Boston Scientific). Follow-up for osteoid osteoma was done without additional imaging, all patients but one were pain free within 2 weeks; this one patient proved to have a chronic osteomyelitis although we thought we saw a nidus on CT. In one patient a burn wound complicated treatment because of unnoticed damage of the isolation layer of the probe. A free skin graft was necessary. We performed MRI controls and curettages for the chondrosarcomas in three patients, in one patient a fracture developed in the calcar femoris region after three months and a hip replacement was done. The patient with chondroblastoma is followed by MRI and there is no activity on contrast MRI two years after the procedure. In one lady a RFA was done for thyroid metastasis in the calcar femoris region. She fractured her collum femoris and got a hip replacement. In all tissue retrieved after RFA (curettage and hip replacement), there was complete necrosis of the tumour (chondrosarcoma grade one and thyroid metastasis). RFA is an effective procedure for osteoid osteoma. Fracture and skin burns can occur. It is promising in low-grade chondrosarcoma and chondroblastoma. A study has been initiated recently to evaluate effectiveness of RFA in low-grade chondrosarcoma < 4 cm