Aims:The most appropriate management of patients who have undergone curettage for a suspected low-grade chondrosarcoma (CS), which has subsequently been found to be of grade 2, remains unknown. We aimed to assess whether these patients have an increased risk of local recurrence and distant metastasis if followed up over time, compared to those who undergo further treatment soon after the diagnosis has been established. Methods:A retrospective study was undertaken which included 71 patients treated between January 2010 and December 2022 by intralesional curettage for a supposed low-grade CS, but who subsequently proved to have a histological grade 2 CS. Thereafter, patients either underwent further surgery (resection group) or follow-up (follow-up group). Results:The estimated local recurrence rate was 36.8% at five (95% CI 35.6 to 38.0) and 48.1% at ten years (95% CI 46.4 to 49.8), and was significantly higher in the follow-up group (48.4%, 95% CI 45.4 to 51.4) than in the resection group (9.6%, 95% CI 8.1 to 11.1) at five years (p = 0.005). Locally recurrent CS, considered as a time-dependent covariate, had an increased risk of metastasis (36.8% vs 2.5% at five years; p < 0.001) and a worse disease-specific survival (81.3% vs 100% at five years; p = 0.007). Conclusion:The optimal treatment strategy should be individualized based on the histological features of the tumour, tumour location, morbidity of resection, and patient-specific factors. We recommend that patients who have undergone unplanned surgery be treated in the standard manner. Observation may be appropriate in specific cases with a properly informed patient.

Aims:The aim of this study was to assess the incidence of reinfection in patients after two-stage revision of an infected megaprosthesis (MPR) implanted after resection of a bone tumour. Methods:A retrospective study was carried out of 186 patients from 16 bone sarcoma centres treated between January 2010 and December 2020. The median age at the time of tumour diagnosis was 26 years (IQR 17 to 33); 69 (37.1%) patients were female, and 117 (62.9%) were male. Results:A total of 186 patients with chronic MPR infections were included. Median follow-up was 68 months (IQR 31 to 105). The most represented sites of MPR were distal femur in 93 cases (50.0%) and proximal tibia in 53 cases (28.5%). Polymicrobial infections were seen in 34 cases (18.3%). The most frequent isolated pathogens were staphylococci. Difficult-to-treat (DTT) pathogens were isolated in 50 cases (26.9%). The estimated infection recurrence (IR) rate was 39.1% at five years and 50.0% at ten years. A higher IR rate was found in DTT PJI compared to non-DTT infections (p = 0.019). Polymicrobial infections also showed a higher rate of infection recurrence (p = 0.046). Conclusion:This study suggests that an infected MPR treated by two-stage revision and ultimately reimplantation with a MPR can be successful, but the surgeon must be aware of a high recurrence rate compared to those seen with infected conventional implants.

Abstract Background Infection is a devastating complication of endoprosthetic replacement (EPR) in orthopaedic oncology. Surgical treatments include debridement and/or one- or two-stage exchange. This study aims to determine the infection-free survival after surgical treatment for first and recurrent EPR infections and identify the risk factors associated with infection recurrence. Methods This single-centre cohort study included all patients with primary bone sarcomas or metastatic bone disease treated for infected EPR between 2010 and 2020. Variables included soft tissue status using McPherson classification, tumour type, silver coating, chemotherapy, previous surgery and microorganisms identified. Data for all previous infections were collected. Survival analysis, with time to recurrent infection following surgical treatment, was calculated at 1, 2 and 4 years. Cox regression analysis was used to assess the influence of different variables on recurrent infection. Results The cohort included 99 patients with a median age of 44 years (29–58 IQR) at the time of surgical treatment. The most common diagnoses were osteosarcoma and chondrosarcoma. One hundred and thirty-three surgical treatments for first or subsequent infections were performed. At 2 years of follow-up, overall success rates were as follows: two-stage exchange 55.3%, one-stage exchange 45.5%, DAIR with an exchange of modular components 44.6% and DAIR without exchange of modular components 24.7%. Fifty-one (52%) patients were infection-free at the most recent follow-up. Of the remaining 48 patients, 27 (27%) were on antibiotic suppression and 21 (21%) had undergone amputation. Significant risk factors for recurrent infection were the type of surgical treatment, with debridement alone as the highest risk (HR 4.75: 95%CI 2.43–9.30; P < 0.001); significantly compromised soft tissue status (HR 4.41: 95%CI 2.18–8.92; P = 0.001); and infections due to Enterococcus spp.. (HR 7.31: 95%CI 2.73–19.52); P = 0.01). Conclusions Two-stage exchange with complete removal of all components where feasible is associated with the lowest risk of recurrent infection. Poor soft tissues and enterococcal infections are associated with higher risks of recurrent infection. Treatment demands an appropriate multidisciplinary approach. Patients should be counselled appropriately about the risk of recurrent infection before embarking on complex treatment.

Primary tumours of bone are a diverse group of lesions that range from benign to malignant neoplasms. While primary benign bone tumours are more prevalent than malignancies in children malignant bone tumours are the seventh most common type of malignancies in children, accounting for roughly 3%–5% of cancers between the ages of 0 and 14 years. Whilst certain aspects of benign bone tumours can be challenging to diagnose and differentiate recent research employing advanced molecular and genetic methodologies has expanded our understanding. This in combination with the neoplasm cell architecture establishes the diagnosis. Whilst recent introduction of massively parallel sequencing-based methods has opened new opportunities for diagnosing bone cancers, the diagnosis of bone lesions is reliant on diagnostic imaging and multidisciplinary team (MDT) discussion. While management of benign tumours is dependent on the diagnosis and clinical features in most cases it requires simple curettage and complete excision.

Background and purpose: Neoadjuvant (NRTX) and adjuvant radiotherapy (ARTX) reduce local recurrence (LR) risk in extremity soft tissue sarcoma (eSTS), yet their impact on distant metastasis (DM) and overall survival (OS) is less well defined. This study aimed at analysing the influence of NRTX/ARTX on all three endpoints using a retrospective, multicentre eSTS cohort.Materials and methods: 1200 patients (mean age: 60.7 +/- 16.8 years; 44.4 % females) were retrospectively included, treated with limb sparing surgery and curative intent for localised, high grade (G2/3) eSTS. 194 (16.2 %), 790 (65.8 %), and 216 (18.0 %) patients had received NRTX, ARTX and no RTX, respectively. For the resulting three groups (no RTX vs. NRTX, no RTX vs. ARTX, NRTX vs. ARTX) Fine&Gray models for LR and DM, and Cox-regression models for OS were calculated, with IPTW-modelling adjusting for imbalances between groups.Results: In the IPTW-adjusted analysis, NRTX was associated with lower LR-risk in comparison to no RTX (SHR [subhazard ratio]: 0.236; p = 0.003), whilst no impact on DM-risk (p = 0.576) or OS (p = 1.000) was found. IPTW-weighted analysis for no RTX vs. ARTX revealed a significant positive association between ARTX and lower LR-risk (SHR: 0.479, p = 0.003), but again no impact on DM-risk (p = 0.363) or OS (p = 0.534). IPTW-weighted model for NRTX vs. ARTX showed significantly lower LR-risk for NRTX (SHR for ARTX: 3.433; p = 0.003) but no difference regarding DM-risk (p = 1.000) or OS (p = 0.639).Conclusion: NRTX and ARTX are associated with lower LR-risk, but do not seem to affect DM-risk or OS. NRTX may be favoured over ARTX as our results indicate better local control rates.

A 17-year-old female patient presented with a 4-week history of a painless, hard lump on the volar aspect of the right wrist.Range of movement, distal neurovascular examination and the overlying skin were normal.There was no history of trauma.

A broad framework of management, from initial evaluation to treatment, is appropriate for all patients with primary bone tumors. Historically the use of radiotherapy in the treatment of primary bone tumors has been of limited value due to the radio-resistance of these tumors and also the inability of primitive radiotherapy delivery techniques safely delivering high doses of radiotherapy. The relationship between the tumor, the adjacent joint, and the neurovascular structures is determined and a resection strategy is formulated. Expert interpretation of the biopsy is essential as most pathologists will be unfamiliar with primary bone tumors and the appearances are often misleading, for instance when distinguishing reactive from tumor bone in bone-forming tumors such as osteosarcoma. Staging is completed by examination of a bone marrow aspirate and trephine biopsy. Chemotherapy is often given after biopsy has established an appropriate diagnosis and before definitive local therapy, so-called neoadjuvant therapy.

Abstract Background Delivering uninterrupted cancer treatment to patients with musculoskeletal tumors has been essential during the rapidly evolving coronavirus 2019 (COVID-19) pandemic, as delays in management can be detrimental. Currently, the risk of contracting COVID-19 in hospitals when admitted for surgery and the susceptibility due to adjuvant therapies and associated mortality due to COVID-19 is unknown, but knowledge of these potential risks would help treating clinicians provide appropriate cancer care. Questions/purposes (1) What is the risk of hospital-acquired COVID-19 in patients with musculoskeletal tumors admitted for surgery during the initial period of the pandemic? (2) What is the associated mortality in patients with musculoskeletal tumors who have contracted COVID-19? (3) Are patients with musculoskeletal tumors who have had neoadjuvant therapy (chemotherapy or radiation) preoperatively at an increased risk of contracting COVID-19? (4) Is a higher American Society of Anesthesiologists (ASA) grade in patients with musculoskeletal tumors associated with an increased risk of contracting COVID-19 when admitted to the hospital for surgery? Methods This retrospective, observational study analyzed patients with musculoskeletal tumors who underwent surgery in one of eight specialist centers in the United Kingdom, which included the five designated cancer centers in England, one specialist soft tissue sarcoma center, and two centers from Scotland between March 12, 2020 and May 20, 2020. A total of 347 patients were included, with a median (range) age of 53 years (10 to 94); 60% (207 of 347) were men, and the median ASA grade was II (I to IV). These patients had a median hospital stay of 8 days (0 to 53). Eighteen percent (61 of 347) of patients had received neoadjuvant therapy (8% [27] chemotherapy, 8% [28] radiation, 2% [6] chemotherapy and radiation) preoperatively. The decision to undergo surgery was made in adherence with United Kingdom National Health Service and national orthopaedic oncology guidelines, but specific data with regard to the number of patients within each category are not known. Fifty-nine percent (204 of 347) were negative in PCR testing done 48 hours before the surgical procedure; the remaining 41% (143 of 347) were treated before preoperative PCR testing was made mandatory, but these patients were asymptomatic. All patients were followed for 30 days postoperatively, and none were lost to follow-up during that period. The primary outcome of the study was contracting COVID-19 in the hospital after admission. The secondary outcome was associated mortality after contracting COVID-19 within 30 days of the surgical procedure. In addition, we assessed whether there is any association between ASA grade or neoadjuvant treatment and the chances of contracting COVID-19 in the hospital. Electronic patient record system and simple descriptive statistics were used to analyze both outcomes. Results Four percent (12 of 347) of patients contracted COVID-19 in the hospital, and 1% (4 of 347) of patients died because of COVID-19-related complications. Patients with musculoskeletal tumors who contracted COVID-19 had increased mortality compared with patients who were asymptomatic or tested negative (odds ratio 55.33 [95% CI 10.60 to 289.01]; p < 0.001).With the numbers we had, we could not show that adjuvant therapy had any association with contracting COVID-19 while in the hospital (OR 0.94 [95% CI 0.20 to 4.38]; p = 0.93). Increased ASA grade was associated with an increased likelihood of contracting COVID-19 (OR 58 [95% CI 5 to 626]; p < 0.001) Conclusion Our results show that surgeons must be mindful and inform patients that those with musculoskeletal tumors are at risk of contracting COVID-19 while admitted to the hospital and some may succumb to it. Hospital administrators and governmental agencies should be aware that operations on patients with lower ASA grade appear to have lower risk and should consider restructuring service delivery to ensure that procedures are performed in designated COVID-19-restricted sites. These measures may reduce the likelihood of patients contracting the virus in the hospital, although we cannot confirm a benefit from this study. Future studies should seek to identify factors influencing these outcomes and also compare surgical complications in those patients with and without COVID-19. Level of Evidence Level III, therapeutic study.

Searchable abstracts of presentations at key conferences on calcified tissues ISSN 2052-1219 (online)

We present a first case of synovial sarcoma in an HIV-positive pregnant woman. This 28-year-old woman was diagnosed with synovial sarcoma, a high-grade malignant soft tissue sarcoma, involving her left thigh during the first trimester of her pregnancy. She underwent surgical treatment in the form of hip disarticulation at 30 weeks' gestation. She was subsequently delivered by emergency caesarean section (CS) at 34 weeks' gestation when she presented with wound sepsis and a scan revealed static growth in a small for gestational age fetus. Prompt diagnosis and treatment of this aggressive tumour is important and should involve a multidisciplinary approach, with a balanced consideration of the maternal and fetal outcomes.

Aims The aim of this study is to assess outcomes of patients <= 12 years who undergo Stanmore noninvasive extendible endoprosthetic replacement of the distal femur (DF NIEPR). Patients and Methods A total of 101 children (mean age 9.6 years) were included. All complications which required further surgery were recorded. Clinical and functional outcomes were evaluated with Musculoskeletal Tumor Society (MSTS) scores at a mean follow-up of 64 months (range 6-174). Results Thirty-one (30.7%) patients died at a mean of 33 months. Forty had prosthesis removed after a mean of 43 months (range, 7-103). Attaining of the full lengthening potential before skeletal maturity was the most frequent reason for revision surgery, particularly in those with smaller lengthening potential (P = 0.039). Implant survival rate for other causes was 61.7% at 5 years and 45.0% at 10 years. At final follow-up mean MSTS score was 26 (range, 13-29). Twenty-two (21.5%) patients had a final limb-length discrepancy (LLD) > 2 cm. Conclusions DF NIEPR produces a good functional outcome, with the prevention of major LLD at skeletal maturity in the majority of the cases. We suggest patient selection criteria to account for the stage of the disease due to the high cost of the NIEPR, and high percentage requiring revision, and a 60% mortality rate in those patients presenting with distant disease burden.

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Background: Dedifferentiated chondrosarcoma (DDC) accounts for a small proportion of chondrosarcomas. They demonstrate aggressive behaviour with a high rate of local recurrence and systemic progression resulting in poor long-term survival rates. Due to its relatively low incidence, previous studies have grouped different histiotypes together to achieve adequate study numbers for analysis. Methods: This retrospective study examines the clinical course and the role of chemotherapy in the subgroup of patients with DDC where osteosarcoma is the predominant dedifferentiated component. Between 2000-2010, 21 patients were identified. Results: The mean age at presentation was 64 years (range 35-80 years). 12 patients were considered unfit for chemotherapy, whilst 2 patients declined chemotherapy. 5 patients received neoadjuvant chemotherapy, with less than 90% necrosis demonstrated in all these cases. 3 patients received post-operative chemotherapy. The median survival for the entire group was 9.5 months. In the 7 patients who received chemotherapy, the median survival was 17 months, and those who had chemotherapy had a greater median time to local recurrence. Conclusion: This study demonstrates that cytotoxic chemotherapy may be offered to appropriately selected patients.

Introduction: Endoprosthetic replacement of the proximal femur is common in the management of bone tumours and failed revision arthroplasty. This study seeks to compare those patients undergoing acetabular resurfacing at the time of femoral replacement with those patients where the native acetabulum was preserved. Methods: All proximal femoral replacements from 2004 to 2009 with a five year follow up were included. Case files were interrogated to identify those that had either revision surgery or dislocation of the hip. Results: 87 patients met the inclusion criteria with an average age of 53 years. 25 operations were for failed revision arthroplasty, 61 for tumours and 1 for osteomyelitis. In 60 patients the acetabulum was resurfaced at surgery, and in 27 patients the acetabulum was preserved. 36 of 60 patients (60%) undergoing immediate resurfacing of the acetabulum had tumours. In patients who did not undergo acetabular resurfacing at surgery 4 sustained dislocations; 1 had surgery for failed revision arthroplasty and 3 tumour resections. Dislocations were significantly lower in the group undergoing immedicate resurfacing p Eighteen of the 87 patients underwent revision surgery (20.7%) although none of these were for recurrent dislocation. 9 of the 27 patients (33.3%) that had a native acetabulum went on to have revision surgery in comparison with 9 (15%) revisions performed in those undergoing acetabular resurfacing at the time of surgery p= 0.02. 83% of revisions were for acetabular wear p Conclusions: Revision and dislocation rates for proximal femoral replacement are significantly lower in those who undergo resurfacing of the acetabulum.

Introduction:Non-invasive extendible endoprostheses (NIEE) were primarily developed for salvage after musculo-skeletal tumour surgery in the immature skeleton. However, they may also have a unique application to manage complex limb reconstruction in revision surgery to address limb-length inequality in the mature skeleton. The aim of this study is to present the minimum 2 –year results of using non-invasive extendible endoprostheses for complex lower limb reconstruction.Methods:Between 2004 and 2013, 21 patients were treated with 23 NIEE. The indication for surgery was salvage of infected prosthesis following primary tumor resection in 6 cases, aseptic prosthesis failure after primary tumour resection in 5 cases, aseptic non-tumor prosthesis failure in 1 case, infected non-tumor prosthesis in 8 cases and symptomatic non-union of graft reconstruction in 3 cases. There were 14 male and 7 female patients with a mean age of 49.8 years (range 19–81).Results:The mean length gained was 41.5 mm (range 0 to 90) re...

Patients with skeletal dysplasia are prone to developing advanced degenerative knee disease requiring total knee replacement (TKR) at a younger age than the general population. TKR in this unique group of patients is a technically demanding procedure due to the bone deformity, flexion contracture, generalised hypotonia and ligamentous laxity. We set out to retrospectively review the outcome of 11 TKR's performed in eight patients with skeletal dysplasia at our institution using the SMILES custom-made rotating-hinge total knee system. There were 3 males and 5 females with mean age 57 years (range, 41–79 years), mean height 138 cm (range, 122–155 cm) and mean weight 56 kg (range, 40–102 kg). Preoperative diagnoses included achondroplasia, spondyloepiphyseal dysplasia, pseudoachondroplasia, multiple epiphyseal dysplasia, morquio syndrome, diastrophic dysplasia and Larson's Syndrome. Patients were followed clinically and radiographically for a mean of 7 years (range, 3–11.5 years). Knee pain and function impr...

IntroductionLocal recurrence of tumours along the biopsy tract is a known complication of percutaneous closed needle biopsy. Correct surgical management requires preoperative identification and excision of the biopsy tract at time of surgery. These tracts become increasingly difficult to identify with time, leading to risk of inadequate excision of the biopsy tract and recurrence of the tumour at the biopsy site.Materials/MethodsIn a prospective study conducted at our institution, 22 of the 45 patients with musculoskeletal tumours (49%) had unidentifiable biopsy sites, with a mean duration between biopsy and definite surgery being 98 days (range 13–164 days). We concluded that identification of the biopsy site was more difficult after 50 days. Radiotherapy related scar formation and the longer time duration between biopsy and definite surgery in patients requiring neoadjuvant therapy made identification more unlikely. Consequently, all patients received India ink skin tattoo to mark the biopsy site at the...