After exclusions, 265 patients with tuberculosis of the thoracic and/or lumbar spine were followed for three years from the start of treatment. They were randomly allocated to four daily regimens of chemotherapy: 1) isoniazid plus rifampicin for 6 months (6HR, 65); 2) the same drugs as in 1) but for 9 months (9HR, 71); 3) isoniazid plus paraaminosalicylic acid (PAS) or ethambutol for 9 months (9P/EH, 62); or 4) the same drugs as in 3) but for 18 months (18P/EH, 67). All patients were ambulatory from the start of chemotherapy and no form of splintage or support or operation was used in any case. Over half (55%) the patients were children and one-third had sinuses or clinically evident abscesses. At three years a favourable status, defined as no sinus nor clinically evident abscess, no myelopathy with functional impairment, no surgery nor additional chemotherapy, full physical activity with disease quiescent clinically and radiographically, was achieved in 203 patients (77%) and in another 41 (15%) in all respects except radiographically. Only 20 patients (8%) had an unfavourable status the proportion being highest (19%) in the 9P/EH series. Thirteen of these were classified as unfavourable solely because they had needed additional chemotherapy; only seven still had an unfavourable status at three years. The clinical results at three years were thus excellent in all series except the 9P/EH, in which more patients had required additional chemotherapy. In the 88 patients with sinuses or abscesses on admission, the rate of resolution was similar in all the series; most lesions (83%) had resolved by 12 months.(ABSTRACT TRUNCATED AT 250 WORDS)

1. Two hundred young Korean patients with a diagnosis of tuberculosis of the spine were allocated at random to in-patient rest in bed (IP) for six months followed by out-patient treatment, or to ambulatory out-patient treatment (OP) from the start. A second random allocation was made to chemotherapy with streptomycin for three months and PAS plus isoniazid for eighteen months (SPH), or to PAS plus isoniazid for eighteen months (PH). For various reasons twenty-nine patients had to be excluded from the study. The main analyses of this report therefore concern 171 patients, namely, forty IP/SPH, forty-six IP/PH, forty-two OP/SPH and forty three OP/PH. The comparisons made are a) of in-patient and out-patient treatment, and b) of the SPH and PH regimens. 2. The clinical and radiographic condition of the four groups on admission was similar. Many patients had extensive lesions. 3. Two in-patients died, probably from miliary tuberculosis, but neither had evidence of residual activity of the spinal lesion. 4. For the eighty-six in-patients the mean stay in hospital was 199 days and five were later readmitted. Of the eighty-five out-patients twenty-one (fourteen SPH, seven PH) were admitted to hospital in the first six months for complications of the spinal disease, for other medical conditions, or for domestic or geographical reasons; after the first six months eight more were admitted. 5. Three in-patients and five out-patients received chemotherapy beyond eighteen months for abscess or for paraparesis. 6. An abscess or sinus was either present initially or developed during treatment in 76 per cent of the in-patients and 72 per cent of the out-patients. Complete resolution occurred in most of the patients, some abscesses being aspirated. At three years 11 per cent of the in-patients and 5 per cent of the out-patients still had residual abscesses or sinuses. 7. On admission the mean total vertebral loss was 1·79 in the in-patients and 1·33 in the out-patients, and increased over the three-year period by 0·15 and 0·31 respectively. 8. The mean angulation of the spine at the start of treatment was 37 degrees for the in-patients and 27 degrees for the out-patients, the mean increase over the three-year period being 8 and 18 degrees respectively. 9. On admission six in-patients and four out-patients had incomplete motor paraplegia. This resolved completely within nine months in eight patients, as did the one cauda equina lesion. Only two patients (both out-patients) developed paraparesis during the course of the study; both recovered. 10. At eighteen months 66 per cent of the in-patients and 58 per cent of the out-patients had responded favourably. The corresponding percentages at thirty-six months were 84 and 88. 11. There was little difference in behaviour between the SPH and the PH series; at thirty-six months 82 per cent of eighty SPH and 90 per cent of eighty-eight PH patients had a favourable response. 12. A multiple regression analysis failed to identify any factor of clearly prognostic importance on admission

In two centres in Korea 350 patients with a diagnosis of tuberculosis of the thoracic and/or lumbar spine were allocated at random: in Masan to in-patient rest in bed (IP) for six months followed by out-patient treatment or to ambulatory out-patient treatment (OP) from the start; in Pusan to out-patient treatment with a plaster-of-Paris jacket (J) for nine months or to ambulatory treatment without any support (No J). All patients recieved chemotherapy with PAS with isoniazid for eighteen months, either supplemented with streptomycin for the first three months (SPH) or without this supplement (PH), by random allocation. The main analysis of this report concerns 299 patients (eighty-three IP, eighty-three OP, sixty-three J, seventy No J; 143 SPH, 156 PH). Pre-treatment factors were similar in both centres except that the patients in Pusan had, on average, less extensive lesions although in a greater proportion the disease was radiographically active. One patient (J/SPH) died with active spinal disease and three (all No J/SPH) with paraplegia. A fifth patient (IP/PH) who died from cardio respiratory failure also had pulmonary tuberculosis. Twenty-three patients required operation and/or additional chemotherapy for the spinal lesion. A sinus or clinically evident abscess was either present initially or developed during treatment in 41 per cent of patients. Residual lesions persisted in ten patients (four IP, two OP, one J, three No J; six SPH, four PH) at five years. Thirty-two patients had paraparesis on admission or developing later. Complete resolution occurred in twenty on the allocated regimen and in eight after operation or additional chemotherapy or both. Of the remaining four atients, all of whom had operation and additional chemotherapy, three died and one still had paraparesis at five years. Of 295 patients assessed at five years 89 per cent had a favourable status. The proportions of the patients responding favourably were similar in the IP (91 per cent) and OP (89 per cent) series, in the J (90 per cent) and No J (84 per cent) series and in the SPH (86 per cent) and PH (92 per cent) series

Streptomycin and the newer antibiotics have already belied the pessimistic agnosticism of 1947. In certain instances, notably in disease of the knee and hip and in some cases with draining sinuses, it appears that they are sufficient to produce a quiescence which may be a cure. For the rest it remains to map out in detail what has in part been explored. In particular it is essential to confirm how far antibiotics enable surgeons to treat tuberculosis upon the basic principles applicable to other infections of bone without fear of secondary infection: where there is diseased bone, to remove it: where there is pus, to relieve the tension and evacuate it. The surgeon fears not so much the infection itself as the inability of the tuberculous soil ordinarily to deal with secondary infection. With the control of the diseased soil the risk should be no greater than that of any other surgery of bone.

The early case and the advanced case; age and site of disease; these and other variables must subdivide basic method. What is the best application of the new "combined operation" to a child of three with thoracic Pott's disease and a globular abscess? What is the wisest plan for a man of forty with old disease in his lumbar vertebrae and discharging sinuses? We begin to see what we could do. At the present the question still remains: What should we do?

We studied 51 patients with osteo-articular tuberculosis who were divided into two groups. Group I comprised 31 newly-diagnosed patients who were given first-line antituberculous treatment consisting of isoniazid, rifampicin, ethambutol and pyrazinamide. Group II (non-responders) consisted of 20 patients with a history of clinical non-responsiveness to supervised uninterrupted antituberculous treatment for a minimum of three months or a recurrence of a previous lesion which on clinical observation had healed. No patient in either group was HIV-positive. Group II were treated with an immunomodulation regime of intradermal BCG, oral levamisole and intramuscular diphtheria and tetanus vaccines as an adjunct for eight weeks in addition to antituberculous treatment. We gave antituberculous treatment for a total of 12 to 18 months in both groups and they were followed up for a mean of 30.2 months (24 to 49). A series of 20 healthy blood donors served as a control group.

Twenty-nine (93.6%) of the 31 patients in group I and 14 of the 20 (70%) in group II had a clinicoradiological healing response to treatment by five months.

The CD4 cell count in both groups was depressed at the time of enrolment, with a greater degree of depression in the group-II patients (686 cells/mm³ (sd 261) and 545 cells/mm³ (sd 137), respectively; p < 0.05). After treatment for three months both groups showed significant elevation of the CD4 cell count, reaching a level comparable with the control group. However, the mean CD4 cell count of group II (945 cells/mm³ (sd 343)) still remained lower than that of group I (1071 cells/mm³ (sd 290)), but the difference was not significant. Our study has shown encouraging results after immunomodulation and antituberculous treatment in non-responsive patients. The pattern of change in the CD4 cell count in response to treatment may be a reliable clinical indicator.

Two hundred and eighty-three patients with tuberculosis of the thoracic and/or lumbar spine have been followed for 10 years from the start of treatment. All patients received PAS plus isoniazid daily for 18 months, either with streptomycin for the first three months (SPH) or no streptomycin (PH), by random allocation. There was also a second random allocation for all patients: in Masan to inpatient rest in bed (IP) for six months followed by outpatient treatment or to ambulatory outpatient treatment from the start (OP), and in Pusan to outpatient treatment with a plaster-of-Paris jacket (J) for nine months or to ambulatory treatment without any support (No J). A favourable status was achieved on their allocated regimen by 88% of patients at 10 years. Some of the remaining patients also attained a favourable status after additional chemotherapy and/or operation, and if these are included the proportion achieving such a status increases to 96%. There were five patients whose deaths were attributed to their spinal disease. A sinus or clinically evident abscess was present on at least one occasion in the 10-year period in 42% of the patients. Residual sinuses persisted at 10 years in two patients, at death at seven years in a third and at default in the seventh year in a fourth. Thirty-five patients had paraparesis at some time during the 10-year period, including two who died with paraplegia before five years. Complete resolution occurred in 26 patients (in six after additional chemotherapy and/or surgery). At 10 years two patients had severe paraplegia and one a moderate paraparesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Streptomycin and iso-nicotinic acid hydrazide are two powerful drugs lethal to tubercle bacilli, when access to the infected tissues is free. For early disease, before ischaemia and necrosis become established, they are curative: afterwards they are not. In this paper the use of surgery to augment their action has been discussed. The development of such methods may well revolutionise the treatment of skeletal tuberculosis. Therein lies a danger because attempts to cure the patient by exterminating the tubercle bacilli in his lesion may lead to a precarious recovery: treatment directed against the bacilli may greatly facilitate a real cure if constitutional treatment is also applied to make the patient immune. Revolutionary though the change may become, it will not be so great as the revolution which occurred thirty years ago when open-air hospitals were first provided for patients with skeletal tuberculosis. The first patient ever seen on a surgical ward by the author, when he was a student, suffices still as an example. A child with tuberculosis of the cervical spine was admitted from out-patients with multiple discharging sinuses from the neck which was supported in a sodden plaster jacket. "Whoever," said the house surgeon dramatically, "removes that plaster, will kill that child." Most unfortunately his words were true. Many other such patients could, in those days, be seen in the wards of city hospitals. It was largely due to the work of Sir Robert Jones, friend of children, that the value of constitutional treatment became recognised. With the combination of the old knowledge and the development of the new, a new chapter in the treatment of skeletal tuberculosis has opened and rapid restoration of function and permanent cure can now take the place of long and sometimes crippling illness.

One hundred and fifty patients in Hong Kong with a diagnosis of tuberculosis of the thoracic, thoracolumbar or lumbar spine were allocated a random to the "Hong Kong" radical resection of the lesion and the insertion of autologous bone grafts (Rad. series) or to debridement of the spinal focus without bone grafting (Deb. series). All patients received daily chemotherapy with para-aminosalicylic acid (PAS) plus isoniazid for 18 months, with streptomycin for the first three months. After exclusions, the main analyses of this report concern 119 patients (58 Rad., 61 Deb.) followed up for 10 years. During the first five years the allocated regimen was modified because of the spinal lesion in 14 patients, but there were no further modifications between five and 10 years. No patient developed a sinus or clinically evident abscess or a neurological abnormality between five and 10 years. Bony fusion occurred earlier and in a higher proportion of patients in the Rad, series but at five and 10 years there was vary little difference between the series. Over the period of 10 years there was a mean increase in vertebral loss of 0.05 of a vertebral body in the Rad. series and 0.23 in the Deb. series. In both series most of this loss occurred in the first 18 months, with very little subsequent change in the next eight and a half years. Over the 10 years there was a mean reduction in the angle of kyphosis in the Rad. series of 1.4 degrees for patients with thoracic and thoracolumbar lesions and 0.5 degrees for those with lumbar lesions. By contrast, in the Deb. series there were mean increases in the angle of 9.8 degrees and 7.6 degrees respectively. In both series most of the changes had occurred early, and persisted subsequently. At 10 years 57 of 58 Rad. and all 61 Deb. patients had a favourable status, 50 (86 per cent) and 54 (89 per cent) respectively on the allocated regimen without modification

Aims. The aim of this study was to determine the rate of indocyanine green (ICG) staining of bone and soft-tissue tumours, as well as the stability and accuracy of ICG fluorescence imaging in detecting tumour residuals during surgery for bone and soft-tissue tumours. Methods. ICG fluorescence imaging was performed during surgery in 34 patients with bone and soft-tissue tumours. ICG was administered intravenously at a dose of 2 mg/kg over a period of 60 minutes on the day prior to surgery. The tumour stain rate and signal-to-background ratio of each tumour were post hoc analyzed. After tumour resection, the tumour bed was scanned to locate sites with fluorescence residuals, which were subsequently inspected and biopsied. Results. The overall tumour stain rate was 88% (30/34 patients), and specific stain rates included 90% for osteosarcomas and 92% for giant cell tumours. For malignant tumours, the overall stain rate was 94%, while it was 82% for benign tumours. The ICG tumour stain was not influenced by different pathologies, such as malignant versus benign pathology, the reception (or lack thereof) of neoadjuvant chemotherapies, the length of time between drug administration and surgery, the number of doses of denosumab for patients with giant cell tumours, or the tumour response to neoadjuvant chemotherapy. The overall accuracy rate of successfully predicting tumour residuals using fluorescence was 49% (23/47 pieces of tissue). The accuracy rate after en bloc resection was significantly lower than that after piecemeal resection (16% vs 71%; p < 0.001). Conclusion. A high percentage of bone and soft-tissue tumours can be stained by ICG and the tumour staining with ICG was stable. This approach can be used in both benign and malignant tumours, regardless of whether neoadjuvant chemotherapy is adopted. The technique is also useful to detect tumour residuals in the wound, especially in patients undergoing piecemeal resection. Cite this article: Bone Joint J 2023;105-B(5):551–558

Aims. The aim of this study was to report the long-term prognosis of patients with multiple Langerhans cell histiocytosis (LCH) involving the spine, and to analyze the risk factors for progression-free survival (PFS). Methods. We included 28 patients with multiple LCH involving the spine treated between January 2009 and August 2021. Kaplan-Meier methods were applied to estimate overall survival (OS) and PFS. Univariate Cox regression analysis was used to identify variables associated with PFS. Results. Patients with multiple LCH involving the spine accounted for 15.4% (28/182 cases) of all cases of spinal LCH: their lesions primarily involved the thoracic and lumbar spines. The most common symptom was pain, followed by neurological dysfunction. All patients presented with osteolytic bone destruction, and 23 cases were accompanied by a paravertebral soft-tissue mass. The incidence of vertebra plana was low, whereas the oversleeve-like sign was a more common finding. The alkaline phosphatase was significantly higher in patients with single-system multifocal bone LCH than in patients with multisystem LCH. At final follow-up, one patient had been lost to follow-up, two patients had died, three patients had local recurrence, six patients had distant involvement, and 17 patients were alive with disease. The median PFS and OS were 50.5 months (interquartile range (IQR) 23.5 to 63.1) and 60.5 months (IQR 38.0 to 73.3), respectively. Stage (hazard ratio (HR) 4.324; p < 0.001) and chemotherapy (HR 0.203; p < 0.001) were prognostic factors for PFS. Conclusion. Pain is primarily due to segmental instability of the spine from its destruction by LCH. Chemotherapy can significantly improve PFS, and radiotherapy has achieved good results in local control. The LCH lesions in some patients will continue to progress. It may initially appear as an isolated or single-system LCH, but will gradually involve multiple sites or systems. Therefore, long-term follow-up and timely intervention are important for patients with spinal LCH. Cite this article: Bone Joint J 2023;105-B(6):679–687

Aims. For paediatric and adolescent patients with growth potential, preservation of the physiological joint by transepiphyseal resection (TER) of the femur confers definite advantages over arthroplasty procedures. We hypothesized that the extent of the tumour and changes in its extent after neoadjuvant chemotherapy are essential factors in the selection of this procedure, and can be assessed with MRI. The oncological and functional outcomes of the procedure were reviewed to confirm its safety and efficacy. Methods. We retrospectively reviewed 16 patients (seven male and nine female, mean age 12.2 years (7 to 16)) with osteosarcoma of the knee who had been treated by TER. We evaluated the MRI scans before and after neoadjuvant chemotherapy for all patients to assess the extent of the disease and the response to treatment. Results. The mean follow-up period was 64.3 months (25 to 148) after surgery and no patients were lost to follow-up. On MRI evaluation, 13 tumours were near but not in contact with the physes and three tumours were partially in contact with the physes before neoadjuvant chemotherapy. Bone oedema in the epiphysis was observed in eight patients. After neoadjuvant chemotherapy, bone oedema in the epiphysis disappeared in all patients. In total, 11 tumours were not in contact and five tumours were in partial contact with the physes. The postoperative pathological margin was negative in all patients. At the last follow-up, 12 patients were continuously disease-free and three had no evidence of disease. One patient died due to the disease. Functionally, the patients with retained allograft or recycled autograft had a mean knee range of flexion of 126° (90° to 150°). The mean Musculoskeletal Tumor Society functional score was 27.6 (23 to 30). Conclusion. TER is an effective limb-salvage technique for treating malignant metaphyseal bone tumours in paediatric and young osteosarcoma patients with open physes when a good response to chemotherapy and no progression of the tumour to the epiphysis have been confirmed by MRI. Cite this article: Bone Joint J 2020;102-B(6):772–778

The February 2024 Oncology Roundup. 360. looks at: Does primary tumour resection improve survival for patients with sarcomas of the pelvis with metastasis at diagnosis?; Proximal femur replacements for an oncologic indication offer a durable endoprosthetic reconstruction option: a 40-year experience; The importance of awaiting biopsy results in solitary pathological proximal femoral fractures: do we need to biopsy solitary pathological fractures?; Effect of radiotherapy on local recurrence, distant metastasis, and overall survival in 1,200 extremity soft-tissue sarcoma patients; What to choose in bone tumour resections? Patient-specific instrumentation versus surgical navigation; Optimal timing of re-excision in synovial sarcoma patients: immediate intervention versus waiting for local recurrence; Survival differences of patients with resected extraskeletal osteosarcoma receiving two different (neo) adjuvant chemotherapy regimens; Solitary versus multiple bone metastases in the appendicular skeleton: should the surgical treatment be different?

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

The December 2022 Oncology Roundup. 360. looks at: Is high-dose radiation therapy associated with early revision with a cemented endoprosthesis?; Neoadjuvant chemotherapy and endoprosthetic reconstruction for lower extremity sarcomas: does timing impact complication rates?; Late amputation after treatment for lower extremity sarcoma; Osteosarcoma prediagnosed as another tumour: a report from the Cooperative Osteosarcoma Study Group; The influence of site on the incidence and diagnosis of solitary central cartilage tumours of the femur: a 21st century perspective

Aims. Clear cell sarcoma (CCS) of soft-tissue is a rare melanocytic subtype of mesenchymal malignancy. The aim of this study was to investigate the clinical and therapeutic factors associated with increased survival, stratified by clinical stage, in order to determine the optimal treatment. Methods. The study was a retrospective analysis involving 117 patients with histologically confirmed CCS, between July 2016 and November 2017, who were enrolled in the Bone and Soft Tissue Tumour Registry in Japan. Results. The five- and ten-year survival rates were 41% (95% confidence interval (CI) 29 to 52) and 37% (95% CI 25 to 49), respectively. On multivariable analysis, the size of the tumour of > 10 cm (p = 0.006), lymph node metastasis at the time of diagnosis (p < 0.001), distant metastases at the time of diagnosis (p < 0.001), and no surgery for the primary tumour (p = 0.019) were independently associated with a poor survival. For N0M0 CCS (n = 68), the development of distant metastases was an independent prognostic factor for survival (early (< 12 months), hazard ratio (HR) 116.78 (95% CI 11.69 to 1,166.50); p < 0.001; late (> 12 months), HR 14.79 (95% CI 1.66 to 131.63); p = 0.016); neoadjuvant/adjuvant chemotherapy (p = 0.895) and/or radiotherapy (p = 0.216) were not significantly associated with survival. The five-year cumulative incidence of local recurrence was 19% (95% CI 8 to 35) and the size of the tumour was significantly associated with an increased rate of local recurrence (p = 0.012). For N1M0 CCS (n = 18), the risk of mortality was significantly lower in patients who underwent surgery for both the primary tumour and lymph node metastases (HR 0.03 (95% CI 0.00 to 0.56); p = 0.020). For M1 CCS (n = 31), excision of the primary tumour was independently associated with better survival (HR 0.26 (95% CI 0.09 to 0.76); p = 0.013). There was no significant difference in survival between the different types of systemic treatment (p = 0.523). Conclusion. Complete excision of the primary tumour and lymph nodes is associated with a better survival in patients with CCS. Systemic treatment appears to provide limited benefits, demonstrating a pressing need for novel systemic agents. Cite this article: Bone Joint J 2023;105-B(11):1216–1225

Aims. The aim of this study was to identify factors that determine outcomes of treatment for patients with chondroblastic osteosarcomas (COS) of the limbs and pelvis. Patients and Methods. The authors carried out a retrospective review of prospectively collected data from 256 patients diagnosed between 1979 and 2015. Of the 256 patients diagnosed with COS of the pelvis and the limbs, 147 patients (57%) were male and 109 patients (43%) were female. The mean age at presentation was 20 years (0 to 90). Results. In all, 82% of the patients had a poor response to chemotherapy, which was associated with the presence of a predominantly chondroblastic component (more than 50% of tumour volume). The incidence of local recurrence was 15%. Synchronous or metachronous metastasis was diagnosed in 60% of patients. Overall survival was 51% and 42% after five and ten years, respectively. Limb localization and wide surgical margins were associated with a lower risk of local recurrence after multivariable analysis, while the response to chemotherapy was not. Local recurrence, advanced patient age, pelvic tumours, and large volume negatively influenced survival. Resection of pulmonary metastases was associated with a survival benefit in the limited number of patients in whom this was undertaken. Conclusion. COS demonstrates a poor response to chemotherapy and a high incidence of metastases. Wide resection is associated with improved local control and overall survival, while excision of pulmonary metastases is associated with improved survival in selected patients. Cite this article: Bone Joint J 2019;101-B:739–744

Aims. The purpose of this study was to clarify the clinical behaviour, prognosis, and optimum treatment of dedifferentiated low-grade osteosarcoma (DLOS) diagnosed based on molecular pathology. Patients and Methods. We retrospectively reviewed 13 DLOS patients (six men, seven women; median age 32 years (interquartile range (IQR) 27 to 38)) diagnosed using the following criteria: the histological coexistence of low-grade and high-grade osteosarcoma components in the lesion, and positive immunohistochemistry of mouse double minute 2 homolog (MDM2) and cyclin-dependent kinase 4 (CDK4) associated with MDM2 amplification. These patients were then compared with 51 age-matched consecutive conventional osteosarcoma (COS) patients (33 men, 18 women; median age 25 years (IQR 20 to 38)) regarding their clinicopathological features. Results. The five-year overall survival (OAS) rates in the DLOS and COS patients were 85.7% and 77.1% (p = 0.728), respectively, and the five-year progression-free survival (PFS) rates were 57.7% and 44.9% (p = 0.368), respectively. A total of 12 DLOS patients received chemotherapy largely according to regimens for COS. Among the nine cases with a histological evaluation after chemotherapy, eight showed a poor response, and seven of these had a necrosis rate of < 50%. One DLOS patient developed local recurrence and five developed distant metastases. Conclusion. Based on our study of 13 DLOS cases that were strictly defined by histological and molecular means, DLOS showed a poorer response to a standard chemotherapy regimen than COS, while the clinical outcomes were not markedly different. Cite this article: Bone Joint J 2019;101-B:745–752

Aims. The aim of this study was to analyse a group of patients with non-metastatic Ewing’s sarcoma at presentation and identify prognostic factors affecting the development of local recurrence, in order to assess the role of radiotherapy. Patients and Methods. A retrospective review of all patients with a Ewing’s sarcoma treated between 1980 and 2012 was carried out. Only those treated with chemotherapy followed by surgery and/or radiotherapy were included. Patients were grouped according to site (central or limb) for further analysis of the prognostic factors. Results. A total of 388 patients were included in the study. Of these, 60 (15%) developed local recurrence at a mean median of 27 months (. sd. 24, range 7 to 150) and the five-year local recurrence-free survival (5yrLRFS) was 83%. For central tumours, the size of the tumour and histological response to chemotherapy were found to be significant factors for local recurrence. For limb tumours, local recurrence was affected by intralesional and marginal resections, but not by the histological response to chemotherapy. Radiotherapy in those with a marginal resection reduced the risk of local recurrence (5yrLRFS: 96% versus 81%, p = 0.044). Conclusion. Local recurrence significantly affects the overall survival in patients with a Ewing’s sarcoma. For those with a tumour in a limb, radiotherapy reduced the risk of local recurrence, especially in those with a marginal margin of excision, but the effect in central tumours was less clear. Radiotherapy for those who have had a wide margin of resection does not reduce the risk of local recurrence, regardless of the histological response to chemotherapy. Cite this article: Bone Joint J 2018;100-B: 247–55