Doppler duplex color localization of osteoid osteomas

Osteoid osteoma of the wrist: Recent advances

Osteoid osteoma is a benign bone tumor usually arising in the diaphysis and metaphysis of the long bones, with male predominance (sex ratio, 2:1). Despite being the most common bone tumor in the wrist, it is still an atypical location for this lesion. The usual presentation is pain that is exacerbated at night and relieved by aspirin or non-steroidal anti-inflammatory drugs. This presentation is not always the case in the wrist, which leads to numerous differential diagnoses and often a delay in definitive diagnosis and treatment. Various imaging modalities can confirm the presence of the tumor and guide the surgical approach. Resection is the gold-standard, with radiofrequency gaining popularity in recent years.

MR Imaging of Osteoid Osteoma: Pearls and Pitfalls

Osteoid osteoma (OO) is a benign bone neoplasm consisting of a central prostaglandin-secreting nidus surrounded by a zone of reactive sclerosis. The diagnosis is suspected in children and young adults with longstanding nighttime pain that is relieved by salicylates or nonsteroidal anti-inflammatory drugs. Early studies suggested that computed tomography had a higher sensitivity and specificity in the diagnosis of OO compared to magnetic resonance imaging (MRI). More recent literature suggests MRI done with dynamic postcontrast imaging to be equal to or slightly better at detecting the nidus of OOs, particularly the ones in atypical locations. Being able to evaluate for OO utilizing MRI is important given that the majority of these lesions occur in younger patients, in whom there is greater concern to limit ionizing radiation. Furthermore, patients with atypical OOs often receive an MRI if radiographs are not suggestive of the diagnosis. Therefore, it is important for radiologists to be aware of the imaging features that can help make the diagnosis on MRI.

Osteoid osteoma: multimodality imaging with focus on hybrid imaging

Osteoid osteoma is a painful, benign, osteoblastic lesion that occurs in younger patients and affects the extremities or the axial skeleton. While plain film findings may suggest the diagnosis, in complex anatomical regions such as the spine, pelvis, wrist and foot advanced imaging modalities are often required. A typical nidus surrounded by sclerosis or cortical thickening characterizes osteoid osteoma on plain radiography and CT. MR is the cross-sectional imaging modality of choice for most musculoskeletal disorders. Unfortunately, extensive accompanying bone marrow oedema, soft-tissue alterations, difficulty detecting the nidus, and lesion locations close to a joint (with reactive arthritis) may make a confident diagnosis of osteoid osteoma by MR imaging difficult. Hybrid imaging with bone-seeking tracers such as SPECT/CT with ^99mTc-labelled bisphosphonates or PET/CT with ¹⁸F-labelled sodium fluoride (¹⁸F-NaF) combines high radionuclide uptake with morphological details and provides accurate diagnosis of osteoid osteoma and additional information for treatment planning. FDG is not the recommended PET tracer because osteoid osteoma is normally FDG-negative, although some osteoid osteomas may show increased FDG uptake. Osteoblastoma, Brodie's abscess and stress fractures may mimic osteoid osteoma on imaging and clinical presentation. Once identified as the pain generator, destruction of the osteoid osteoma nidus by ablation or resection techniques usually leads to complete healing. Image-guided drill excision and radiofrequency ablation are widely used interventions. We review the presentation of osteoid osteoma across all imaging modalities, with special focus on hybrid imaging techniques.

Gamma Probe Localization in the Surgical Treatment of Osteoid Osteoma

Background:

Osteoid osteoma is a benign bone tumor typically inducing night pain. It has traditionally been treated with operative excision. An accurate localization and complete removal of the small lesion is difficult resulting in high recurrence rate and reoperations.

Aims:

The purpose of the present study was to examine the applicability of a handheld gamma probe in the intraoperative localization of an osteoid osteoma.

Material and Methods:

Five patients were examined and operated for osteoid osteoma. Dose of 740 MBq Technetium 99m was injected 3 hours before operation, and handheld gamma probe was used for the intraoperative detection of the lesion.

Results:

All patients were relieved their symptoms. A histologically confirmed, complete removal of the lesion was achieved in 4 of 5 patients. No recurrences has been seen in the follow-up of 6 years.

Conclusions:

The gamma probe is an useful tool in the surgical treatment of osteoid osteoma. The technique is rapid and simple resulting in more accurate excision of the small lesion.

Osteoid osteoma treated with radiofrequency ablation

Purpose. Our aim is to evaluate the results of treatment with computed tomography (CT) guided percutaneous radiofrequency ablation for osteoid osteomas which were localized in a difficult area for operation. Materials and Methods. Glenoid, distal tibia, humerus shaft, proximal humerus, and in third finger of the hand proximal phalanx were involved in one patient. Proximal femur was involved in three patients, distal femur was involved in three patients, and proximal tibia was involved in two patients. 9 males and 4 females were aged 4 to 34 years (mean age: 18.5 years). All patients had pain and were evaluated with X-rays, CT, bone scintigraphy, and MRI. In all patients, RF ablation was performed with local anesthesia. The lesion heated to 90°C for 6 minutes. Results. All of the patients achieved complete pain relief after ablation and were fully weight bearing without any support. In all patients, there was soft tissue edema after the procedure. During follow-up, all patients were free from the pain and there was no sign about the tumor. There was no other complication after the process. Conclusion. CT guided RFA is a minimally invasive, safe, and cost-effective treatment for osteoid osteoma placed in difficult area for surgery.

Radiofrequency thermal ablation of osteoid osteomas of the proximal femur. Usefulness of ultrasound guidance in selected cases

PURPOSE

To review symptoms and imaging findings of proximal femoral osteoid osteomas (OO); to analyse the results of a thermal ablation technique for radiofrequency of the nidus in this location; and to describe usefulness of ultrasound guidance in selected cases.

MATERIAL AND METHOD

Descriptive and retrospective study consisting of 8 patients with OO in the proximal epiphysis of the femur, which were treated by thermal ablation of the nidus with radiofrequency waves from 1998 to 2004.

RESULTS

The mean pain period until the performance of the thermal ablation was 11.5 months (range 5-18 months). There were no complications, and all patients stated that the pain was gone by the day following the procedure, with some discomfort during the first week, except for one where it lasted more than one month due to technique difficulties. At present, with a mean follow up of 6 years and 2 months (range 6-190 months), all patients remain asymptomatic and live a rigorous normal life.

DISCUSSION

Thermal ablation with CT-guided radiofrequency waves is a safe, effective and efficient procedure.

CONCLUSION

Normal appearance of a proximal femoral OO does not differ significantly from other location osteomas and its diagnosis is easier with previous knowledge. Thermal ablation of the nidus with radiofrequency waves, that may be performed using ultrasound guidance, appears to be the elective treatment of choice due to its efficiency and minimum morbidity.

Osteoid osteoma

Osteoid osteomas consist of a nidus with surrounding sclerotic bone. The differential diagnosis covers a wide range of conditions due to the variable presentation of osteoid osteoma. The natural history is for regression to occur within 6 to 15 years with no treatment; however, this can be reduced to 2 to 3 years with the use of aspirin and non-steroidal anti-inflammatory drugs. Computed tomography-guided percutaneous techniques, including trephine excision, cryoablation, radiofrequency ablation, and laser thermocoagulation, are described.

Osteoid osteomas: a pain in the night diagnosis

Osteoid osteoma is a common benign bone-forming lesion that is composed of a nidus of vascular osteoid tissue and woven bone lined by osteoblasts. It is frequently associated with considerable surrounding inflammation. The diagnosis is usually straightforward when imaging reveals a radiolucent nidus surrounded by variable degrees of reactive sclerosis. However, the diagnosis can be elusive when osteoid osteomas occur in atypical locations, as they may have a nonspecific and misleading appearance on different imaging modalities, particularly on MRI. The purpose of this pictorial essay is to review the typical and atypical features of osteoid osteomas on different imaging modalities, and the appearance of osteoid osteomas in different locations. We also review growth disturbances caused by osteoid osteomas and potential mimickers, with imaging characteristics that can aid in diagnosis.

Osteoid osteoma of the radial styloid mimicking wrist arthritis: a case study

Osteoid osteoma in the wrist and hand region is an uncommon but severely symptomatic primary bone tumour. We report the case of a professional athlete with a radial styloid osteoid osteoma who presented with significant wrist pain and stiffness resembling arthritis for which she was treated initially. The symptoms started after a fall on the outstretched hand and significant delay in the diagnosis occurred. Following detailed imaging evaluation of the tumour site excision biopsy was curative.

Osteoid osteoma--the CT vessel sign

OBJECTIVE

To evaluate whether the presence of a feeding vessel in proximity to osteoid osteomas of long bones on multidetector CT (MDCT) can be an adjuvant clue for the diagnosis of osteoid osteoma.

MATERIALS AND METHODS

Forty-nine CT scans of patients with radiological and clinical diagnosis of osteoid osteoma of long bones and a control group of 20 CT scans of patients with cortical-based lesions other then osteoid osteoma were analyzed. Two radiologists evaluated the CT images in consensus for the presence of a blood vessel in the same axial slices in which the nidus of osteoid osteoma was seen and to determine the incidence.

RESULTS

In 39 cases (79.6%) of osteoid osteoma, a blood vessel either entered the nidus (23 patients) or was seen in proximity to it (16 patients). This was significantly different (P < 0.05) from the cortical-based lesions, in which only two CT scans (10%) showed a blood vessel in the lesion's proximity.

CONCLUSION

In the majority of osteoid osteoma lesions in long bones, a blood vessel can be seen on MDCT either entering the nidus itself or in its proximity. The role of this vessel in the lesion pathogenesis and whether it improves diagnostic accuracy need further evaluation.

Percutaneous radiofrequency ablation of osteoid osteomas with use of real-time needle guidance for accurate needle placement: a pilot study

PURPOSE

To evaluate the accuracy and technical success of positioning a radiofrequency ablation (RFA) electrode in osteoid osteomas by use of a new real-time needle guidance technology combining cone-beam computed tomography (CT) and fluoroscopy.

MATERIALS AND METHODS

Percutaneous RFA of osteoid osteomas was performed in five patients (median age 18 years), under general anesthesia, with the use of cone-beam CT and fluoroscopic guidance for electrode positioning. The outcome parameters were technical success, meaning correct needle placement in the nidus; accuracy defined as the deviation (in mm) from the center of the nidus; and clinical outcome at follow-up.

RESULTS

In all five cases, positioning was possible within 3 mm of the determined target location (median nidus size 6.8 mm; range 5-10.2 mm). All procedures were technically successful. All patients were free of pain at clinical follow-up. No complications were observed.

CONCLUSION

Real-time fluoroscopy needle guidance based on cone-beam CT is a useful tool to accurately position radiofrequency needles for minimally invasive treatment of osteoid osteomas.

Histological study of osteoid osteoma's blood supply

The osteoid osteoma is a painful lesion with a special predilection for the femur and tibia of young patients. Although the lesion has been described as richly innervated, its vascular supply has not been critically appraised to date in the pathology literature. To this end, we have undertaken a morphological study of 16 archival cases of osteoid osteoma, focusing primarily on the patterns of vascularization, utilizing traditional histological and immunohistochemical approaches. The study demonstrated that a prominent arterial and arteriolar blood supply was a constant finding within the various zones of soft tissues, skeletal muscle, and bone surrounding the nidus. It also showed that the caliber of the vessels underwent gradual attenuation throughout their centripetal course toward the nidus, where the vessels lost their muscularis as they merged into the capillary network of the nidus. Immunostaining with antibodies to neurofilament and S100 proteins revealed a pattern of innervation that was overall less exuberant than that described in some reports and that was virtually absent from the nidus. Taken together with data reported in the radiological literature, our findings lead us to wonder whether the osteoid osteoma may represent a response to the local stimulation of bony tissue by a primarily aberrant vasculature, a hypothesis that warrants further elucidation using state-of-the-art imaging approaches.

Intraarticular osteoid osteoma: sonographic findings in three patients with radiographic, CT, and MR imaging correlation

OBJECTIVE

Intraarticular osteoid osteoma often has subtle radiographic findings and nonspecific clinical features; further diagnostic workup of unexplained joint pain may involve musculoskeletal sonography. We describe the sonographic features of intraarticular osteoid osteoma in three consecutive patients with radiographic, CT, and MR imaging correlation.

CONCLUSION

The sonographic findings of painful cortical irregularity and focal synovitis should raise the possibility of intraarticular osteoid osteoma, prompting the search for characteristic findings on correlative imaging studies.