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Department of Radiology
Seth G.S. Medical College and K.E.M. Hospital, Mumbai , India
Interventional Case Record
Interventional Case Record
Contributed by Ranjeet Kumar A. Singh
Contributed by Ranjeet Kumar A. Singh
Radiofrequency ablation of Osteoid osteoma
Radiofrequency ablation of Osteoid osteoma
Introduction:
Introduction:
Osteoid osteoma is a painful benign bony condition represents 12% of benign bone tumors that typically occurs in children and young adults.(1) It characteristically causes night-pain which is relieved on using non-steroidal anti-inflammatory drugs. They have typical radiological finding of lucent nidus <1.5 cm and surrounding solid periosteal reaction. Surgical removal or ablation of the nidus is key to the successful treatment outcome in this condition, and open surgery has been considered traditionally to be a gold standard in the treatment of osteoid osteoma.(2) However, surgery is not devoid of technical difficulties and morbidities and suffers from local recurrence rates ranging 9–28%, as reported in the literature.(2)To avoid these issues various minimally invasive image-guided percutaneous procedures have been tried to treat this painful condition, of which radiofrequency ablation (RFA) is proving to be an attractive alternative to surgery.
Osteoid osteoma is a painful benign bony condition represents 12% of benign bone tumors that typically occurs in children and young adults.(1) It characteristically causes night-pain which is relieved on using non-steroidal anti-inflammatory drugs. They have typical radiological finding of lucent nidus <1.5 cm and surrounding solid periosteal reaction. Surgical removal or ablation of the nidus is key to the successful treatment outcome in this condition, and open surgery has been considered traditionally to be a gold standard in the treatment of osteoid osteoma.(2) However, surgery is not devoid of technical difficulties and morbidities and suffers from local recurrence rates ranging 9–28%, as reported in the literature.(2)To avoid these issues various minimally invasive image-guided percutaneous procedures have been tried to treat this painful condition, of which radiofrequency ablation (RFA) is proving to be an attractive alternative to surgery.
We present a case report highlighting the unusual location and atypical imaging characteristics of an osteoid osteoma in the juxta-articular region of the femoral head, and treatment of the condition with radiofrequency ablation. Now a days, radiofrequency ablation is preferred treatment option for osteoid osteoma as it is low in both risk and morbidity in the cases that are difficult to access surgically.
We present a case report highlighting the unusual location and atypical imaging characteristics of an osteoid osteoma in the juxta-articular region of the femoral head, and treatment of the condition with radiofrequency ablation. Now a days, radiofrequency ablation is preferred treatment option for osteoid osteoma as it is low in both risk and morbidity in the cases that are difficult to access surgically.
Case presentation
Case presentation
A 35 year old male patient presented with dull aching night pain in the right hip since 6 months. It was associated with low grade fever. Pain was relieved on using pain relieving drugs for a while.
A 35 year old male patient presented with dull aching night pain in the right hip since 6 months. It was associated with low grade fever. Pain was relieved on using pain relieving drugs for a while.
On bilateral hip radiograph, (FIGURE 1) there is a well-defined lytic lesion of approximate size 12x10 mm, with sclerotic margin is seen in a subarticular location in the right femoral head. There is no associated periosteal reaction or fracture. No evidence of similar lesions in the rest of the visualized bones.
On bilateral hip radiograph, (FIGURE 1) there is a well-defined lytic lesion of approximate size 12x10 mm, with sclerotic margin is seen in a subarticular location in the right femoral head. There is no associated periosteal reaction or fracture. No evidence of similar lesions in the rest of the visualized bones.
On T1 weighted MRI imaging,(FIGURE 2) well defined hypo-intensity seen in right femoral head. Adjacent soft tissue appears normal.
On T1 weighted MRI imaging,(FIGURE 2) well defined hypo-intensity seen in right femoral head. Adjacent soft tissue appears normal.
Based on the imaging features a diagnosis of osteoid osteoma was made.
Based on the imaging features a diagnosis of osteoid osteoma was made.
Fig. 1
Fig. 1
Fig. 2
Fig. 2
After informed consent was obtained it was decided to perform a radiofrequency ablation. Under general anesthesia the nidus was localized with 3 mm CT sections and osseous access was established with a 4.5 mm drill. On an axial CT section with radiofrequency ablation (RFA) needle placed within the drilled tract (FIGURE 3 & 3a) After localization, the RFA needle was introduced through the drilled canal and tip placed in the nidus. Monopolar RFA was performed at a 90°C for a period of 5 minutes at 60 W. Post ablation CT shows residual air pockets (FIGURE 4).
After informed consent was obtained it was decided to perform a radiofrequency ablation. Under general anesthesia the nidus was localized with 3 mm CT sections and osseous access was established with a 4.5 mm drill. On an axial CT section with radiofrequency ablation (RFA) needle placed within the drilled tract (FIGURE 3 & 3a) After localization, the RFA needle was introduced through the drilled canal and tip placed in the nidus. Monopolar RFA was performed at a 90°C for a period of 5 minutes at 60 W. Post ablation CT shows residual air pockets (FIGURE 4).
Fig. 3
Fig. 3
Fig. 3a
Fig. 3a
Fig. 4
Fig. 4
Discussion :
Discussion :
Osteoid osteoma is a benign osteogenic tumor which affects children and young adults. Clinically, patients are presented with localized severe bone pain typically in the night, which is characteristically relieved by nonsteroidal anti-inflammatory drugs.(3) Patients may also present with growth disturbances, bone deformity, and if located within a joint capsule, there might be joint effusion, synovitis, restricted joint motion, or contracture.(4) Characteristic radiographic findings include a nidus of vascular osteoid tissue in the bone cortex surrounded by reactive sclerotic bone. CT is often used as a modality of choice for detecting this tumor and provides the best characterization of the nidus and the surrounding sclerotic bone. MRI, though not as specific as CT but very well depicts the adjacent marrow edema and synovial changes in the lesion close to the joint capsule.
Osteoid osteoma is a benign osteogenic tumor which affects children and young adults. Clinically, patients are presented with localized severe bone pain typically in the night, which is characteristically relieved by nonsteroidal anti-inflammatory drugs.(3) Patients may also present with growth disturbances, bone deformity, and if located within a joint capsule, there might be joint effusion, synovitis, restricted joint motion, or contracture.(4) Characteristic radiographic findings include a nidus of vascular osteoid tissue in the bone cortex surrounded by reactive sclerotic bone. CT is often used as a modality of choice for detecting this tumor and provides the best characterization of the nidus and the surrounding sclerotic bone. MRI, though not as specific as CT but very well depicts the adjacent marrow edema and synovial changes in the lesion close to the joint capsule.
Radiofrequency ablation is an excellent alternative to surgical excision in the foveal region as it avoids the complications associated with surgical exposure of the femoral head, including injury to the capsular vessels and post-operative capsular laxity. It also avoids weakening of the femoral neck by large diameter drilling for surgical access and chondral or osteochondral damage from resection of the subchondral lesion. Osteoid osteoma in a femoral head is associated with a potential risk of avascular necrosis as foveal artery is seen in a close proximity of the in the ligamentum teres.(5) The foveal artery is a branch of posterior division of the obturator artery, which becomes important to avoid avascular necrosis of the head of the femur when the blood supply from the medial and lateral circumflex arteries are disrupted.
Radiofrequency ablation is an excellent alternative to surgical excision in the foveal region as it avoids the complications associated with surgical exposure of the femoral head, including injury to the capsular vessels and post-operative capsular laxity. It also avoids weakening of the femoral neck by large diameter drilling for surgical access and chondral or osteochondral damage from resection of the subchondral lesion. Osteoid osteoma in a femoral head is associated with a potential risk of avascular necrosis as foveal artery is seen in a close proximity of the in the ligamentum teres.(5) The foveal artery is a branch of posterior division of the obturator artery, which becomes important to avoid avascular necrosis of the head of the femur when the blood supply from the medial and lateral circumflex arteries are disrupted.
RFA is a better option than surgery in this location as it avoids injury to the articular margin, prevents capsular injury and reduces the risk of weakening the femoral neck. Injury to the foveal artery with the potential risk of avascular necrosis must be kept in mind when the lesion is close to the fovea of the femoral head.(6)
RFA is a better option than surgery in this location as it avoids injury to the articular margin, prevents capsular injury and reduces the risk of weakening the femoral neck. Injury to the foveal artery with the potential risk of avascular necrosis must be kept in mind when the lesion is close to the fovea of the femoral head.(6)
References:
References:
1. Unni KK, (Ed) Dahlin's Bone Tumours: General Aspects and Data on 11,087 Cases. Philadelphia, PA: Lippincott-Raven; 1996. [Google Scholar]
1. Unni KK, (Ed) Dahlin's Bone Tumours: General Aspects and Data on 11,087 Cases. Philadelphia, PA: Lippincott-Raven; 1996. [Google Scholar]
2. Unni KK, Dahlin DC. Osteoid osteoma. In: Dahlin's bone tumors. 5th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 1996. p. 121-30. Back to cited text no. 2
2. Unni KK, Dahlin DC. Osteoid osteoma. In: Dahlin's bone tumors. 5th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 1996. p. 121-30. Back to cited text no. 2
3. Vigorita VJ, Ghelman B, Mintz D. In: Orthopaedic Pathology. Vigorita VJ, editor. Philadelphia, PA: Lippincott Williams & Wilkins; 2007. Bone tumours; p. 339. [Google Scholar]
3. Vigorita VJ, Ghelman B, Mintz D. In: Orthopaedic Pathology. Vigorita VJ, editor. Philadelphia, PA: Lippincott Williams & Wilkins; 2007. Bone tumours; p. 339. [Google Scholar]
4. Cantwell CP, O'Byrne J, Eustace S. Radiofrequency ablation of osteoid osteoma with cooled probes and impedance-control energy delivery. AJR Am J Roentgenol 2006;186:244-8. Back to cited text no. 3
4. Cantwell CP, O'Byrne J, Eustace S. Radiofrequency ablation of osteoid osteoma with cooled probes and impedance-control energy delivery. AJR Am J Roentgenol 2006;186:244-8. Back to cited text no. 3
5. Kransdorf MJ, Stull MA, Gilkey FW, Moser RP. Osteoid osteoma. Radiographics 1991;11:671-96. Back to cited text no. 4
5. Kransdorf MJ, Stull MA, Gilkey FW, Moser RP. Osteoid osteoma. Radiographics 1991;11:671-96. Back to cited text no. 4
6. Kneisl JS, Simon MA. Medical management compared with operative treatment for osteoid-osteoma. J Bone Joint Surg Am1992;74:179-85. Back to cited text no. 5
6. Kneisl JS, Simon MA. Medical management compared with operative treatment for osteoid-osteoma. J Bone Joint Surg Am1992;74:179-85. Back to cited text no. 5
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