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

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

Introduction. The use of computer navigation has a potential to allow precise tumour resection and accurate reconstruction of the resultant defect. This can be useful in difficult areas such as pelvis, diaphyseal (intercalary) resections and geometric bony resections. Methods. We have carried out resections of musculoskeletal tumours in 7 patients using an existing commercial computer navigation system (Orthomap 3D). CT & MRI scans of each patient were fused preoperatively using navigation software and the tumour margins were marked. The planes of tumour resection were defined on the 3D image generated. During surgery, trackers were attached to bone with tumour and registration performed. Instruments attached to navigation tracker were then used to identify the predetermined resection points. Of the 4 pelvic tumours, 1 had biological reconstruction with extra corporeal irradiation, 3 had endoprosthetic replacement & 1 did not need any bony reconstruction. 1 patient with proximal femur tumour needing extraarticular resection had endoprosthetic replacement. The 2 tibial diaphyseal tumours had biological reconstruction. Results. Examination of the resected specimens revealed tumour free margins. Postoperative radiographs showed resection and reconstruction as planned in all cases. In the patient with extraarticular proximal femur resection the hip joint was inadvertently exposed whilst making the acetabular osteotomy & in one patient with pelvic tumour the intra-operative registration could not be accurately performed as she was overweight and a real time matching of anatomy & virtual images was not achieved. Discussion and Conclusion. The use of computer navigation in musculoskeletal oncology allows integration of local anatomy and tumour extent and thus resection margins can be identified accurately. Our experience so far has been encouraging. Further clinical trials (multicentre) are required to evaluate its long term impact including functional & oncological outcomes

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

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

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

Functional outcomes are commonly reported in studies of musculoskeletal oncology patients undergoing limb salvage surgery; however, interpretation requires knowledge of the smallest amount of improvement that is important to patients – the minimally important difference (MID). We established the MIDs for the Musculoskeletal Tumor Society Rating Scale (MSTS) and Toronto Extremity Salvage Score (TESS) in patients with bone tumors undergoing lower limb salvage surgery. This study was a secondary analysis of the recently completed PARITY (Prophylactic Antibiotic Regimens in Tumor Surgery) study. This data was used to calculate: (1) the anchor-based MIDs using an overall function scale and a receiver operating curve analysis, and (2) the distribution-based MIDs based on one-half of the standard deviation of the change scores from baseline to 12-month follow-up, for both the MSTS and TESS. There were 591 patients available for analysis. The Pearson correlation coefficients for the association between changes in MSTS and TESS scores and changes in the external anchor scores were 0.71 and 0.57, indicating “high” and “moderate” correlation. Anchor-based MIDs were 12 points and 11 points for the MSTS and TESS, respectively. Distribution-based calculations yielded MIDs of 16-17 points for the MSTS and 14 points for the TESS. The current study proposes MID scores for both the MSTS and TESS outcome measures based on 591 patients with bone tumors undergoing lower extremity endoprosthetic reconstruction. These thresholds will optimize interpretation of the magnitude of treatment effects, which will enable shared decision-making with patients in trading off desirable and undesirable outcomes of alternative management strategies. We recommend anchor-based MIDs as they are grounded in changes in functional status that are meaningful to patients

Aim

While the association of surgery and radiation therapy in high grade Soft Tissue Sarcoma (STS) of extremities is considered the “golden standard”, there is not international agreement regarding type, timing, overall dose of radiation, and size, site and histology of tumours to be irradiated. A similar consideration is about low grade STS. The aim of our paper is critically reconsider our experience, trough a retrospective analysis of 15 years experience. This in order to propose a perspective protocol of treatment of high and low grade STS, in order to minimize the late complication rate.

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

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

The surgical management of musculoskeletal tumours is a challenging problem, particularly in pelvic and diaphyseal tumour resection where accurate determination of bony transection points is extremely important to optimise oncologic, functional and reconstructive options. The use of computer assisted navigation in these cases could improve surgical precision. We resected musculoskeletal tumours in fifteen patients using commercially available computer navigation software (Orthomap 3D). Of the eight pelvic tumours, three underwent biological reconstruction with extra corporeal irradiation; three endoprosthetic replacement (EPR) and two required no bony reconstruction. Four diaphyseal tumours had biological reconstruction. Two patients with proximal femoral sarcoma underwent extra-articular resection and EPR. One soft tissue sarcoma of the adductor compartment involving the femur was resected with EPR. Histological examination of the resected specimens revealed tumour free margins in all cases. Post-operative radiographs and CT show resection and reconstruction as planned in all cases. Several learning points were identified related to juvenile bony anatomy and intra-operative registration. The use of computer navigation in musculoskeletal oncology allows integration of local anatomy and tumour extent to identify resection margins accurately. Furthermore, it can aid in reconstruction following tumour resection. Our experience thus far has been encouraging

The surgical management of musculoskeletal tumours is a challenging problem, particularly in pelvic and diaphyseal tumour resection where accurate determination of bony transection points is extremely important to optimise oncologic, functional and reconstructive options. The use of computer assisted navigation in these cases could improve surgical precision and achieve pre-planned oncological margins with improved accuracy. We resected musculoskeletal tumours in ten patients using commercially available computer navigation software (Orthomap 3D, Stryker UK Ltd). Of the five pelvic tumours, two underwent biological reconstruction with extra corporeal irradiation, two endoprosthetic replacement (EPR) and one did not require bony reconstruction. Three tibial diaphyseal tumours had biological reconstruction. One patient with proximal femoral sarcoma underwent extra-articular resection and EPR. One soft tissue sarcoma of the adductor compartment involving the femur was resected with EPR. Histological examination of the resected specimens revealed tumour free margins in all cases. Post-operative radiographs and CT show resection and reconstruction as planned in all cases. Several learning points were identified related to juvenile bony anatomy and intra-operative registration. The use of computer navigation in musculoskeletal oncology allows integration of local anatomy and tumour extent to identify resection margins accurately. Furthermore, it can aid in reconstruction following tumour resection. Our experience thus far has been encouraging. Further clinical trials are required to evaluate its long-term impact on functional & oncological outcomes

Background. The surgical management of musculoskeletal tumours is a challenging problem, particularly in pelvic and diaphyseal tumour resection where accurate determination of bony transection points is extremely important to optimise oncologic, functional and reconstructive options. The use of computer assisted navigation in these cases could improve surgical precision. Materials and methods. We resected musculoskeletal tumours in fifteen patients using commercially available computer navigation software (Orthomap 3D). Results. Of the eight pelvic tumours, three underwent biological reconstruction with extra corporeal irradiation, three endoprosthetic replacement (EPR) and two required no bony reconstruction. Four diaphyseal tumours had biological reconstruction. Two patients with proximal femoral sarcoma underwent extra-articular resection and EPR. One soft tissue sarcoma of the adductor compartment involving the femur was resected with EPR. Histological examination of the resected specimens revealed tumour free margins in all cases. Post-operative radiographs and CT show resection and reconstruction as planned in all cases. Several learning points were identified related to juvenile bony anatomy and intra-operative registration. Discussion. The use of computer navigation in musculoskeletal oncology allows integration of local anatomy and tumour extent to identify resection margins accurately. Furthermore, it can aid in reconstruction following tumour resection. Our experience thus far has been encouraging

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

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.

Functional outcomes are important for patients with bone tumors undergoing lower extremity endoprosthetic reconstruction; however, there is limited empirical evidence evaluating function longitudinally. The objective of this study was to determine the changes in function over time in patients undergoing endoprosthetic reconstructions of the proximal femur, distal femur and proximal tibia.

We conducted a secondary analysis of functional outcome data from the Prophylactic Antibiotic Regimens in Tumor Surgery (PARITY) trial. Patient function was assessed with the Musculoskeletal Tumor Society Score 93 (MSTS) and the Toronto Extremity Salvage Score (TESS), which were administered preoperatively and at 3, 6 and 12 months postoperatively. Both instruments are scored from 0-100, with higher scores indicated greater function. Mean functional scores were evaluated over time and we explored for differences among patients undergoing proximal femur reconstructions (PFR), distal femur reconstructions (DFR) and proximal tibia reconstructions (PTR). The patient-importance of statistically significant differences in function was evaluated utilizing the minimally important difference (MID) of 12 for the MSTS and 11 for the TESS. We explored for differences in change scores between each time interval with paired t-tests. Differences based on endoprosthetic reconstruction undertaken were evaluated by analysis of variance and post-hoc comparisons using the Tukey test.

A total of 573 patients were included. The overall mean MSTS and TESS scores were 77.1(SD±21) and 80.2(SD±20) respectively at 1-year post-surgery, demonstrating approximately a 20-point improvement from baseline for both instruments. When evaluating change scores over time by type of reconstruction, PFR patients experienced significant functional improvement during the 3-6 and 6-12 month follow-up intervals, DFR patients demonstrated significant improvements in function at each follow-up interval, and PTR patients reported a significant decrease in function from baseline to 3 months, and subsequent improvements during the 3-6 and 6-12 month intervals.

On average, patients undergoing endoprosthetic reconstruction of the lower extremity experience important improvements in function from baseline within the first year. Patterns of functional recovery varied significantly based on type of reconstruction performed. The results of this study will inform both clinicians and patients about the expected rehabilitation course and functional outcomes following endoprosthetic reconstruction of the lower extremity.

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

Objective. was to review the experience of the Rizzoli with megaprosthetic reconstruction of the extremities in musculoskeletal oncology. Material and methods. Between April 1983 and December 2007, 1036 modular uncemented megaprostheses of the lower limbs were implanted in 605 males and 431 females: 160 KMFTR(r), 633 HMRS(r) prostheses, 68 HMRS(r) Rotating Hinge and 175 GMRS(r). Sites: distal femur 659, proximal tibia 198, proximal femur 145, total femur 25, distal femur and proximal tibia 9. Histology showed 612 osteosarcomas, 113 chondrosarcomas, 72 Ewing's sarcoma, 31 metastatic carcinomas, 89 GCT, 36 MFH,68 other diagnoses. Between 1975 and 2006 at Rizzoli 344 reconstructions of the humerus using prosthetic devices (alone or in association with allografts) were performed: 289 MRS(r), 37 HMRS(r), 2 Osteobridge(r), 4 composite prostheses, 8 Coonrad-Morrey(r), 4 custom made prostheses. Sites of reconstruction were: proximal humerus 311, distal humerus 19, diaphysis 5, total humerus 9. Histology showed 146 osteosarcomas, 56 chondrosarcomas, 23 Ewing's sarcoma, 67 metastatic carcinomas, 14 GCT, 10 MFH, 28 other diagnoses. Patients were followed periodically in the clinic. Information were obtained from clinical charts and imaging studies with special attention to major complications requiring revision surgery. Major prostheses-related complications were analysed and functional results evaluated according to the MSTS system. Univariate analysis by Kaplan-Meier actuarial curves was used for studying implant survival to major complications. Results. Major complications causing implants failure in lower limbs were 80 infections (7.7%), 64 aseptic loosening (6.2%) and 33 breakages (3.2%). In lower limbs infection occurred in 18 KMFTR(r), 47 HMRS(r), 5 HMRS(r) Rotating Hinge, 10 GMRS(r). Breakage of the prosthetic reconstruction occurred in 16 KMFTR(r), 16 HMRS(r), 1 HMRS(r) Rotating Hinge. Aseptic loosening occurred in 15 KMFTR(r), 28 HMRS(r), 18 HMRS(r) Rotating Hinge, 3 GMRS(r). Major complications causing implants failure in upper limbs were 15 infections (4.3%), 8 aseptic loosening (2.3%) and 4 breakages (1.2%). In upper limbs infection occurred in 14 MRS(r) and 1 Coonrad-Morrey(r). Aseptic loosening in 8 cases MRS(r). Breakage in 4 cases MRS(r) prostheses. Most patients in both lower and upper extremities series showed satisfactory function (good or excellent) according to the MSTS evaluation system. Implant survival to all major complications of lower limb megaprostheses evaluated with Kaplan-Meier curve was 80% at 10 years and 60% at 20 years. Implant survival for the newer designs (GMRS(r)) available only at middle term follow up showed an implant survival to major complications at about 90% at 5 years. Implant survival to all major complications was over 80% at 10 years and 78% at 20 years. Conclusions. Megaprostheses are the most frequently used type of reconstruction after resection of the extremities, since they provide good function and a relatively low incidence of major complications. Both function and implant survival improved in the last decades with the introduction of newer designs and materials

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