Aims. Venous tumour thrombus (VTT) is a rare finding in osteosarcoma. Despite the high rate of VTT in osteosarcoma of the pelvis, there are very few descriptions of VTT associated with extrapelvic primary osteosarcoma. We therefore sought to describe the prevalence and presenting features of VTT in osteosarcoma of both the pelvis and the limbs. Methods. Records from a single institution were retrospectively reviewed for 308 patients with osteosarcoma of the pelvis or limb treated between January 2000 and December 2022. Primary lesions were located in an upper limb (n = 40), lower limb (n = 198), or pelvis (n = 70). Preoperative imaging and operative reports were reviewed to identify patients with thrombi in proximity to their primary lesion. Imaging and histopathology were used to determine presence of tumour within the thrombus. Results. Tumours abutted the blood vessels in 131 patients (43%) and encased the vessels in 30 (10%). Any form of venous thrombus was identified in 31 patients (10%). Overall, 21 of these thrombi were determined to be involved with the tumour based on imaging (n = 9) or histopathology (n = 12). The rate of VTT was 25% for pelvic osteosarcoma and 1.7% for limb osteosarcoma. The most common imaging features associated with histopathologically proven VTT were enhancement with contrast (n = 12; 100%), venous enlargement (n = 10; 83%), vessel encasement (n = 8; 66%), and visible intraluminal osteoid matrix (n = 6; 50%). Disease-specific survival (DSS) for patients with VTT was 95% at 12 months (95% CI 0.87 to 1.00), 50% at three years (95% CI 0.31 to 0.80), and 31% at five years (95% CI 0.14 to 0.71). VTT was associated with worse DSS (hazard ratio 2.3 (95% CI 1.11 to 4.84). Conclusion. VTT is rare with osteosarcoma and occurs more commonly in the pelvis than the limbs. Imaging features suggestive of VTT include enhancement with contrast, venous dilation, and vessel encasement. VTT portends a worse prognosis for patients with osteosarcoma, with a similar survivability to metastatic disease. Cite this article: Bone Joint J 2024;106-B(8):865–870

Neoadjuvant chemotherapy for osteosarcoma improves outcomes for the majority, but if the chemotherapy does not work then the dilemma often arises as to whether to do limb salvage with a marginal (or worse) margin of excision or to do an amputation. If limb salvage is carried out with a close margin, does post operative radiotherapy make any difference? This study aims to address these questions. Method. All patients with limb osteosarcoma, no metastases, a poor response to chemotherapy and either a marginal excision or primary amputation were identified from a prospective database. This group were investigated in terms of overall survival and local control. Results. There were 182 patients in this category of whom 60 had an amputation, 105 limb salvage with marginal margins and 17 with an intralesional margin. Local recurrence (LR) arose in 41% of those with an intralesional margin, 22% of those with a marginal margin and 13% of those with an amputation. Radiotherapy was used in 21 of the 122 patients and the risk of LR was the same as in those who did not have radiotherapy. Neither age nor sex of the patient, size or site of the tumour affected the risk of LR. The overall survival for this group was 42% at 10 years. The survival was best in those with marginal margins (38%) than those with an amputation (28%) and worst for those with an intralesional margin (20%). Survival was worst in those who did develop LR, but no worse than in those having amputation. Conclusion. A marginal resection of osteosarcoma with a poor response to chemotherapy leads to a high risk of local recurrence but also carries a poor prognosis. Carrying out an amputation to avoid the risk of LR probably has little survival benefit and the use of radiotherapy remains unclear

We aimed to identify the incidence, outcome and prognostic factors associated with spindle cell sarcomas of bone (SCSB). We studied 196 patients with a primary non-metastatic tumour treated with the intent to cure. The results were compared with those of osteosarcoma patients treated at our hospital during the same period. The overall incidence of SCSB was 7.8% of all patients with a primary bone sarcoma. The five- and ten-year survival rates were 67.0% and 60.0%, respectively, which were better than those of patients with osteosarcoma treated over the same period. All histological subtypes had similar outcomes. On univariate analysis, factors that were significantly associated with decreased survival were age > 40 years, size > 8 cm, the presence of a pathological fracture, amputation, involved margins and a poor response to pre-operative chemotherapy. Multivariate analyses showed that age > 65 years, amputation and involved margins were all statistically significant prognostic factors. Involved margins and poor response to pre-operative chemotherapy were associated with an increased risk of local recurrence. SCSB has a better prognosis than osteosarcoma when matched for age. Most prognostic factors for osteosarcoma also seem to apply to SCSB. Patients with SCSB should be treated in the same way as patients of the same age with osteosarcoma.