Aims. Treatment of high-grade limb bone sarcoma that invades a joint requires en bloc extra-articular excision. MRI can demonstrate joint invasion but is frequently inconclusive, and its predictive value is unknown. We evaluated the diagnostic accuracy of direct and indirect radiological signs of intra-articular tumour extension and the performance characteristics of MRI findings of intra-articular tumour extension. Methods. We performed a retrospective case-control study of patients who underwent extra-articular excision for sarcoma of the knee, hip, or shoulder from 1 June 2000 to 1 November 2020. Radiologists blinded to the pathology results evaluated preoperative MRI for three direct signs of joint invasion (capsular disruption, cortical breach, cartilage invasion) and indirect signs (e.g. joint effusion, synovial thickening). The discriminatory ability of MRI to detect intra-articular tumour extension was determined by receiver operating characteristic analysis. Results. Overall, 49 patients underwent extra-articular excision. The area under the curve (AUC) ranged from 0.65 to 0.76 for direct signs of joint invasion, and was 0.83 for all three combined. In all, 26 patients had only one to two direct signs of invasion, representing an equivocal result. In these patients, the AUC was 0.63 for joint effusion and 0.85 for synovial thickening. When direct signs and synovial thickening were combined, the AUC was 0.89. Conclusion. MRI provides excellent discrimination for determining intra-articular tumour extension when multiple direct signs of invasion are present. When MRI results are equivocal, assessment of synovial thickening increases MRI’s discriminatory ability to predict intra-articular joint extension. These results should be interpreted in the context of the study’s limitations. The inclusion of only extra-articular excisions enriched the sample for true positive cases. Direct signs likely varied with tumour histology and location. A larger, prospective study of periarticular bone sarcomas with spatial correlation of histological and radiological findings is needed to validate these results before their adoption in clinical practice. Cite this article: Bone Jt Open 2024;5(10):944–952

Aims

Intra-articular (IA) tumours around the knee are treated with extra-articular (EA) resection, which is associated with poor functional outcomes. We aim to evaluate the accuracy of MRI in predicting IA involvement around the knee.

Introduction. Bone tumours rarely involve the joint surface as cartilage is thought to be a good barrier to tumour spread. When the tumour does cross the surface the surgeon is faced with the dilemma of whether to amputate the limb, resect it without reconstruction or reconstruct with an implant. This paper aims to investigate the oncological and functional outcomes of patients undergoing an extra-articular resection and reconstruction with an endoprosthesis. Method. 3100 patients have been seen in ROH with primary bone tumours. Patients were identified who had an extra-articular resection considered pre-operatively and the notes and imaging was reviewed. This group was subdivided into a group who did have an extra-articular resection (EAR) and those who either had an amputation or traditional through joint resection. The outcomes of the three groups (group 1 = no joint involvement, group 2 = EAR considered but not done and group 3 = EAR) were then compared in terms of oncological outcome, surgical margins and complications. Results. EAR was considered in 94 cases (3%) usually due to either obvious tumour or joint effusion on initial imaging. Of these 94 cases an EAR was undertaken in 66 cases and not in 28 cases. There was no difference in age, site distribution, diagnosis between the groups. The mean size of the tumour was smaller in the EAR group. The percentage of wide margins achieved was significantly smaller in the EAR group and risk of local recurrent disease was greater in the EAR group but mainly in patients with chondrosarcoma. There was no difference in patient survival between the groups. Conclusions. EAR gives acceptable oncological and functional results but has significantly higher rates of locally recurrent disease in patients with chondrosarcoma

Aims

Tenosynovial giant cell tumour (TGCT) is one of the most common soft-tissue tumours of the foot and ankle and can behave in a locally aggressive manner. Tumour control can be difficult, despite the various methods of treatment available. Since treatment guidelines are lacking, the aim of this study was to review the multidisciplinary management by presenting the largest series of TGCT of the foot and ankle to date from two specialized sarcoma centres.

We undertook this retrospective study to determine the rate of recurrence and functional outcome after intralesional curettage for chondroblastoma of bone. The factors associated with aggressive behaviour of the tumour were also analysed. We reviewed 53 patients with histologically-proven chondroblastoma who were treated by intralesional curettage in our unit between 1974 and 2000. They were followed up for at least two years to a maximum of 27 years.

Seven (13.2%) had a histologically-proven local recurrence. Three underwent a second intralesional curettage and had no further recurrence. Two had endoprosthetic replacement of the proximal humerus and two underwent below-knee amputation after aggressive local recurrence. One patient had the rare malignant metastatic chondroblastoma and eventually died. The mean Musculoskeletal Tumour Society functional score of the survivors was 94.2%.

We conclude that meticulous intralesional curettage alone can achieve low rates of local recurrence and excellent long-term function.