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

We describe 100 consecutive patients with osteoid osteoma. Of the 97 who had operations, 89 were treated by intralesional excision and eight by wide resection. The three remaining patients were not operated on because the osteoid osteoma was almost painless, or was found in the pedicle of the 12th thoracic vertebra at the site of entrance of the artery of Adamkjewicz. The diagnosis was confirmed histologically in all specimens. No local recurrences were observed at a minimum follow-up of one year. All except one patient were mobilised two to four days after surgery. A precise preoperative diagnosis of the lesion is mandatory, based on clinical findings, standard radiographs, thin-section CT and a bone scan. We compared our operative technique with 247 cases in which the percutaneous technique of removal or coagulation of the nidus had been performed. The latter procedure has a less constant rate of primary cure (83% v 100%). Its principal indication appears to be for osteoid osteomas in the proximal femur and the pelvis

1. A case of osteoid osteoma of the skull is reported, with characteristic clinical, radiological and pathological features. 2. Osteoid osteoma of the skull has not previously been reported

Subperiosteal osteoid osteoma in a juxta-articular site presents a diagnostic challenge. The clinical features of joint stiffness, synovitis, muscle atrophy and local warmth may suggest arthritis rather than osteoid osteoma, while radiographs, bone scans and angiograms may not be diagnostic. We describe four cases of this rare condition

A case of intracortical haemangioma in the tibial diaphysis is reported. The radiological and macroscopic features were identical with osteoid osteoma. In view of this similarity, haemangiomata, despite their rarity at this site, must be considered in the differential diagnosis of osteoid osteoma

We treated 58 patients with osteoid osteoma by CT-guided radiofrequency ablation (RF). In 16 it followed one or two unsuccessful open procedures. It was performed under general anaesthesia in 48, and spinal anaesthesia in ten. The nidus was first located by thin-cut CT (2 to 3 mm) sections. In hard bony areas a 2 mm coaxial drill system was applied. In softer areas an 11-gauge Jamshidi needle was inserted to allow the passage of a 1 mm RF probe into the centre of the nidus. RF ablation was administered at 90°C for a period of four to five minutes. Three patients had recurrence of pain three, five and seven months after treatment, respectively, and a second percutaneous procedure was successful. Thus, the primary rate of success for all patients was 95% and the secondary rate was 100%. One minor complication was encountered. CT-guided RF ablation is a safe, simple and effective method of treatment for osteoid osteoma

1. Specimens are described in which osteoid was seen in undecalcified bone sections prepared from a number of osteoarthritic femoral heads. 2. It was localised mostly in the pressure segments. 3. The reason for the presence of this osteoid is not well understood and the possibilities of local histochemical changes and/or cellular metaplasia are discussed

1. Three cases of a benign osteoblastic lesion of bone are described. An outstanding feature of each was the hyperostosis of adjacent bones or synovitis in an adjacent joint. 2. The clinical, radiological and histological features resembled osteoid osteomata more than benign osteoblastoma in each case. 3. The significance of this observation is questioned in relation to the pathogenesis of osteoid osteoma

1. A case of an osteoid osteoma in the terminal phalanx of a finger is recorded. 2. Unusual features were enlargement of the finger with nail hypertrophy, sweating, and premature fusion of the epiphysis

1. Two cases of osteoid osteoma of the vertebrae are presented. 2. The unusual clinical histories and findings are reported in detail

1. A case of osteoid osteoma which recurred twice after block excision is reported. 2. It is postulated that recurrence is almost certainly caused by incomplete removal of the nidus, either by curettage or by incomplete block excision. 3. Why curettage is successful in most cases but not in others is obscure, but it may be that the arterial supply to the tumour is interrupted. 4. Block excision with adequate radiographic control to ensure its completeness is the treatment of choice

We treated 106 patients with a peripheral osteoid osteoma by conventional surgical methods; 81 had curettage and 25 en-bloc resection. The rate of local recurrence after curettage was 12% and after en-bloc resection 4.5%. Postoperative fractures were observed in 3% after curettage and in 4.5% after en-bloc resection. We compared our findings with those reported in the literature after minimally invasive treatment and concluded that curettage can be regarded as the treatment of choice in patients in whom minimally invasive methods do not offer any advantage, for example, for subperiosteal tumours which are readily accessible, or when the diagnosis is unclear and further histological analysis is required

1. The clinical features in twenty cases of osteoid osteoma have been analysed and compared with other cases reported in the literature. 2. The lesion is regarded as a benign neoplasm and its unusual clinical behaviour is attributed to its vascular nature. 3. The frequency with which an erroneous diagnosis of "neurosis" is made is stressed

Seven patients with osteoid osteoma of the proximal femur were treated by percutaneous excision of the nidus. The combination of preoperative localisation by tomography and intraoperative localisation by image intensifier resulted in a curative procedure with minimal bone resection in all cases, although a second operation was required in one patient

We report the results of a prospective study of 23 patients in which interstitial laser photocoagulation (ILP) was used to treat an osteoid osteoma. ILP is a technique in which tumour tissue is destroyed by direct heating using low-power laser light energy delivered by thin (400 μm) optical fibres which are introduced percutaneously into the tumour under image guidance. Pain was evaluated before operation and at the latest follow-up using a visual analogue scale with 0 denoting no pain and 10 the worst pain imaginable. The mean follow-up was for 15 months. The results showed that the mean pain score decreased from 7.5 before operation to 0.95 at the latest follow-up. Fourteen patients had no pain and eight had minor discomfort, not requiring analgesia. One patient required a second procedure because placement of the fibre had not been accurate enough and one developed recurrent symptoms eight months after treatment. All patients were satisfied with the operation because of the rapid resolution of pain, the minimally invasive nature of the procedure, and the fact that there was no postoperative restriction of activity

We review the case of a 58-year-old man with a benign osteoblastic lesion. This originated in the base of the right second metacarpal and eventually involved several adjacent bones, persisting for at least 27 years despite 11 operations. It was originally reported in the literature as a recurrent osteoid osteoma, but we believe it is more properly diagnosed as an aggressive osteoblastoma, since the histological pattern did not change over the years. The lesion has remained locally aggressive with no evidence of malignant characteristics

The behaviour pattern of the scoliosis associated with osteoid osteoma or osteoblastoma of the spine is described. In patients presenting with symptoms at or around skeletal maturity, the scoliosis is postural. Excision of the lesion ensures complete resolution of the curve. In the growing child, however, an initial postural scoliosis may develop vertebral rotation with structural characteristics. The magnitude of the curve and the associated vertebral rotation is dependent on the time interval between the onset of symptoms and the surgical treatment. Although removal of the lesion usually results in regression of the curve, a prolonged delay in treatment may result in a progressive structural scoliosis. A possible mechanism for the behaviour of the scoliosis is discussed

The clinical presentation and treatment of 18 cases of osteoid osteoma or osteoblastoma of the spine are described, with an average follow-up of 4.2 years (range three months to 11.5 years). The average delay between the onset of symptoms and definitive diagnosis was 19 months. All patients presented with marked spinal stiffness and a painful scoliosis. The lesion was situated in the pedicle in the 15 patients with involvement of the thoracolumbar spine. A surgical approach allowing direct access to the pedicle without entering the spinal canal or jeopardising spinal stability is described. Surgical treatment afforded immediate relief of pain and an early return of full spinal mobility