Unusually located osteoid osteomas

Interest of targeted computed tomography guided by scintigraphy in the diagnosis of an osteoid osteoma of the talus: A surgical case report

INTRODUCTION AND IMPORTANCE

Osteoid osteoma is a benign primary bone tumor with a predilection for the long bones and vertebrae, presenting a unique challenge when occurring in rare locations such as the talus, accounting for 5 to 8 % of cases. Early imaging struggles to detect its nidus, leading to diagnostic delays, especially when atypical symptoms and previous trauma complicate clinical presentations. This case report illustrates the diagnostic challenges and emphasizes the importance of targeted computed tomography (CT) guided by scintigraphy in diagnosing osteoid osteoma of the talus.

CASE PRESENTATION

A 23-year-old male presented with chronic left ankle pain spanning three years, with a history of previous trauma. Initial evaluations including standard radiology and magnetic resonance imaging (MRI) suggested algodystrophy of the talus and tenosynovitis, but failed to identify the osteoma. Persistent pain led to further investigation with bone scintigraphy, revealing hyperfixation indicative of partial algodystrophy. Targeted CT scans focused on the scintigraphy-identified area ultimately revealed an osteoid osteoma's nidus, enabling successful surgical intervention and symptomatic relief.

DISCUSSION

The diagnosis of osteoid osteoma in the talus is frequently delayed due to its atypical presentation and rare occurrence. Traditional imaging techniques may overlook the tumor's nidus, underscoring the necessity for targeted diagnostic approaches. This case demonstrates the value of integrating scintigraphy with targeted CT to enhance early diagnosis and treatment planning, contrasting with the limited diagnostic yield of MRI and underscoring CT's superiority for nidus detection.

CONCLUSION

Osteoid osteoma of the talus poses significant diagnostic challenges. This case report highlights the utility of scintigraphy-guided targeted CT in identifying the nidus and facilitating prompt surgical management, advocating for a multidisciplinary approach to atypical ankle pain, especially in patients with a history of trauma.

Intraoperative Identification and Mosaicplasty in a Case of Femur Subchondral Osteoid Osteoma

Osteoid osteomas (OOs) are non-malignant primary bone abnormalities marked by a central nidus surrounded by reactive sclerosis. They typically manifest as aggravated nocturnal pain that responds to non-steroidal anti-inflammatory drugs (NSAIDs). These growths are most frequently found within the intracortical bone and the diaphysis of elongated bones. Within the realm of uncommon conditions, intra-articular OOs (IAOOs) exhibit distinctive presentations, often leading to postponed or inaccurate diagnoses. We present a patient with OO at the distal femur, accessible through the knee joint, which was intraoperatively identified and localized using a needle pricking technique and treated by arthrotomy and mosaicplasty.

Intra- and Juxta-Articular Osteoid Osteoma Mimicking Arthritis: Case Series and Literature Review

BACKGROUND

Intra- and juxta-articular osteoid osteomas are rare, representing less than 10% of all osteomas. Compared to the classic diaphyseal or metaphyseal site of long bones, they often have an atypical onset, a longest diagnostic delay, and frequent initial misdiagnoses, with pictures that can mimic inflammatory monoarthritis. We aimed to describe a case series, and to provide a literature review of this uncommon and misleading tumor location.

METHODS

We performed a retrospective analysis of patients referred to three pediatric rheumatology centers, with a final diagnosis of articular osteoid osteoma. A review of the literature was additionally conducted.

RESULTS

We included 10 patients with a mean age of 14 years. All patients with unusual sites (olecranon fossa, lumbar vertebra, distal phalanx of the toe, fibula) had a misdiagnosis, and cases with initial suspicion of monoarthritis had the longest diagnostic delay, up to 24 months. The literature review confirms the significant risk of misdiagnosis, and an average time from symptom onset to diagnosis ranging from 0.4 to 1.8 years.

CONCLUSIONS

Articular osteoid osteoma may mimic arthritis, especially in adolescence. Knowledge of the atypical forms of presentation, and of the clinical and radiological pitfalls, reduces the risk of diagnostic error.

Midterm Clinical, Radiological, and Functional Results of Arthroscopic Excision of Osteoid Osteoma of the Hip Joint: a Case Series

Purpose

We aimed to evaluate the midterm functional and clinical outcomes of the patients who underwent arthroscopic excision of hip osteoid osteoma (OO).

Methods

We reviewed records of patients diagnosed with intra-articular hip OO, treated with hip arthroscopic excision procedure, and a minimum of 1-year postoperative between 2011 and 2020. Clinical outcomes were assessed range of motion (ROM) pre and postoperatively, and functional outcomes were evaluated with a modified Harris hip score (modified HHS) and Visual analog scale test. All patients were assessed by hip radiography, and three radiological measurements, including lateral center-edge angle (LCEA), alpha angle, and Tönnis angle, were measured. These parameters were compared with unaffected hips.

Results

Fifteen (5 female and 10 male) patients were included in the study, with a mean age of 32.6 ± 12.7 (range 12-53). The average postoperative follow-up period was 59.1 ± 28 (range 13-106) months. The functional and clinical scores were significantly improved at the final visit compared to the preoperative values. No differences were found between the operated and unaffected sides with respect to the radiological parameters. The preoperative alpha was significantly higher on the operated side than on the unaffected side (p = 0.007).

Conclusion

In this study, within an average of 5 years after surgery, hip arthroscopy provided successful clinical outcomes in the treatment of OO of the hip joint without recurrence. The modified HHS, VAS, and HOS values improved significantly at the final follow-up; 14 of 15 patients had satisfactory outcomes after hip arthroscopy for hip OO.

Level of Evidence

Prognostic Level IV study.

Bir çocukta ön diz ağrısının nadir bir nedeni: Patellar Osteoid Osteoma ve literatürün gözden geçirilmesi

Giriş: Osteoid Osteoma (OO) belirgin bir nidus ve onu çevreleyen sklerotik reaktif zon ile karakterize küçük selim bir kemik tümörüdür. Genellikle uzun kemiklerde yerleşmekle birlikte nadiren patellada da görülebilmektedir.Vaka Sunumu: Sekiz yaşında kız çocuğu ön diz ağrısı şikayetiyle polikliniğimize başvurdu. Hastanın ağrı şikayetleri yaklaşık bir yıldır mevcuttu. Hastada Patellar Osteoid Osteoma tespit edildi. Lezyon kürete edildi ve cerrahi sonrası ilk gün hastanın ağrıları tamamen geçti.Sonuç: Her ne kadar Patellar OO nadir gözükse de çocuk ve genç erişkinlerdeki uzun süreli diz ağrısının ayırıcı tanısında düşünülmesi gerekir.Anahtar Kelimeler: Osteoid Osteoma, patella, diz ağrısı, küretaj, gecikmiş tanı, kemik neoplazmı

Intra-articular osteoid osteoma of the capitulum: A diagnostic challenge

Here, we describe the first case of intra-articular osteoid osteoma of the capitulum, which is presented as elbow pain, extension lack, and sensation of click in joint flexion. Surgical treatment either arthroscopic or open is more in use in this location of the tumor than cortical osteoid osteoma.

Intraarticular Osteoid Osteoma: MRI Characteristics and Clinical Presentation Before and After Radiofrequency Ablation Compared to Extraarticular Osteoid Osteoma

PURPOSE

 To determine MRI characteristics and the clinical presentation of intraarticular osteoid osteomas (OO) before and after treatment with CT-guided radiofrequency ablation (RFA) compared with extraarticular osteoid osteomas.

MATERIALS AND METHODS

 In a retrospective study, n = 21 patients with an intraarticular OO were matched with a control group of n = 21 patients with an extraarticular OO at a comparable anatomical position. All patients underwent CT-guided RFA and preinterventional MRI. In n = 31 cases, follow-up MR imaging was available. MR images were analyzed for morphologic features: effusion and synovitis, bone marrow edema (BME), soft tissue edema, periosteal reaction as well as T1 / T2 signal and contrast enhancement of the nidus. Recorded clinical parameters included the initial diagnosis, the course of pain symptoms after RFA and the incidence of complications.

RESULTS

 The nidus was detectable in all patients on MRI. BME had the highest sensitivity in both intra- and extraarticular OO (100 %). Effusion and synovitis were only observed in the intraarticular OO group (n = 21) with a perfect sensitivity and specificity (100 %) and a high negative predictive value (85 %). Soft tissue edema was significantly more present in patients with intraarticular OO (p = 0.0143). No significant differences were present regarding periosteal reaction, T1/T2 signal and contrast enhancement of the nidus (p > 0.05). BME, contrast enhancement, soft tissue edema, periosteal reaction, effusion and synovitis, if preexisting, always decreased after RFA. In 66.7 % of patients with intraarticular OO, a false initial diagnosis was made (extraarticular: 19 %). All patients were free of pain after intervention. Complications following the RFA procedure did not occur.

CONCLUSION

 MRI demonstrates the nidus and thus the OO in all cases regardless of the location. The characteristic MRI morphology of an intraarticular OO includes synovitis and joint effusion, which are always present and differentiate with perfect sensitivity/specificity from an extraarticular OO. In both intra- and extraarticular OOs pathologic MRI changes at least decreased or completely normalized and the clinical results after RFA were excellent.

KEY POINTS

  · MRI is excellently suited for the diagnosis of intra- and extraarticular OOs.. · Joint effusion and synovitis distinguish both forms with perfect sensitivity and specificity.. · All MRI changes, which indicate activity, decreased after successful RFA.. · The clinical results after RFA are excellent in both forms..

CITATION FORMAT

· Germann T, Weber M, Lehner B et al. Intraarticular Osteoid Osteoma: MRI Characteristics and Clinical Presentation Before and After Radiofrequency Ablation Compared to Extraarticular Osteoid Osteoma. Fortschr Röntgenstr 2020; 192: 1190 - 1198.

Arthroscopic management of intra- and juxta-articular osteoid osteoma of the upper extremity: a systematic review of the literature

BACKGROUND

Intra- and juxta-articular osteoid osteoma (OO) is rare and can result in irreversible joint damage. Recently, arthroscopic surgery is being used more and more to avoid complications associated with other treatment modalities.

METHODS

On October 13, 2019, we conducted a systematic review of the literature available in PubMed and EMBASE regarding the arthroscopic management of OO involving the joints of the upper extremity. Predetermined inclusion criteria were used to include any relevant article published on and before that date for further analysis. Treatment success rate and tumor recurrence rate were considered the primary outcomes in our analysis.

RESULTS

Out of 113 studies, 19 met our inclusion criteria. Of the 32 reported cases in these 19 articles, ten involved the shoulder joint, 19 involved the elbow joint and three involved the wrist joint. Overall treatment success rate was 93.8%. Tumor recurrence rate was 0.0%. No postoperative complications (0.0%) were reported among cases involving the shoulder joint. Two out of 24 (8.3%) patients with elbow OO failed arthroscopic treatment due to incomplete excision, and two (4%) experienced minor complications. Among the three cases of wrist OO, two (66.7%) patients had residual postoperative pain and decreased hand grip strength.

CONCLUSION

Arthroscopic management of OO of the upper extremity joints is highly successful and results in no tumor recurrence; however, there is a risk of incomplete resection in areas more difficult to access by arthroscopy.

A case report of an unrecognized osteoid osteoma of the proximal femur

We present the case of a 59-year-old male patient with unrecognized osteoid osteoma in radiography as well as in magnetic resonance imaging. Computed tomography revealed osteoid osteoma that was successfully treated with percutaneous computed tomography guided radiofrequency ablation. The osseous pathology was underestimated on magnetic resonance imaging in the presented case and bone marrow edema led to incorrect diagnosis. The particular case emphasizes the value of computed tomography scans diagnosing an osteoid osteoma.

A Rare Cause of Anterior Knee Pain in a Young Athlete and a Delayed Diagnosis: Osteoid Osteoma of the Patella

Intra-articular osteoid osteomas are a rare cause of articular pain. Their diagnosis can be challenging due to their non-specific clinical presentation and imaging characteristics. We present the case of a young soccer player with a 12-month history of anterior knee pain that was first attributed to Sinding Larsen Johansson syndrome and then to Hoffa’s syndrome. A CT scan was performed that revealed the localization of an osteoid osteoma of the patella. The patient was successfully treated by percutaneous radiofrequency ablation under CT guidance without complications and returned to full sports activity. Although a rare entity, osteoid osteoma of the patella with its atypical clinical features could be included in the differential diagnosis of persistent anterior knee pain in the young adult. High clinical suspicion is necessary to avoid delay in diagnosis and irrelevant procedures for the patient.

Intra-articular osteoid osteoma accompanied by extensive bone marrow edema. A clinical and micro-morphological analysis

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A series of patients with intra-articular osteoid osteoma (OO) is demonstrated.

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Extensive and persistent bone marrow edema syndrome masked the correct diagnosis.

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No consistent patterns of impaired bone mineral status could be confirmed in these patients.

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Nidus specimens displayed significantly higher mineralization heterogeneity determined by qBEI.

Osteoid osteoma (OO) is a benign bone tumor producing non-mineralized bone matrix (i.e., osteoid). While peritumoral edema is commonly found in OO, extensive bone marrow edema has been reported less frequently. Furthermore, the micro-morphological characteristics of the nidus and its central calcification remain unclear. In this study, a consecutive series of four patients suffering from extensive bone marrow edema triggered by intra-articular osteoid osteoma underwent clinical examination, magnetic resonance imaging (MRI) and computed tomography (CT) as well as dual-energy X-ray absorptiometry (DXA) and laboratory bone turnover analyses. The obtained resection specimens were processed by undecalcified histology and were subsequently analyzed by light microscopy and quantitative backscattered electron imaging (qBEI). We report an entity of intra-articular osteoid osteoma in the knee and foot, in which an extensive and persistent bone marrow edema syndrome masked the correct diagnosis. While metabolic bone diseases were excluded in all cases, the reassessment of the patients’ clinical history including pain characteristics (nocturnal, aspirin sensitivity) led us to perform additional CT, where the tumor was diagnosed. The micro-morphological analysis of the OO biopsies revealed that the nidus was surrounded by hyperosteoidosis, while central mineralization was detected in all cases. This mineralized area showed a significantly higher mineralization heterogeneity than the surrounding trabecular bone and more disorganized collagen fibers detected by qBEI and polarized light microscopy, respectively. Taken together, our results indicate that osteoid osteoma should be considered when persistent and extensive, peri-articular bone marrow edema is diagnosed. The central calcification that is found inside the nidus in conventional imaging was mirrored by bone matrix with a heterogeneous mineralization pattern.

Intra-articular Osteoid Osteoma of the Distal Femur Treated with Osteochondral Grafting: A Report of 2 Cases

CASE

Intra-articular osteoid osteoma (IAOO) is a relatively rare entity and can pose a therapeutic challenge due to proximity to the cartilage surface. We present 2 cases of subchondral osteoid osteomata within the distal femur treated with excision and osteochondral grafting of the resultant defect.

CONCLUSIONS

Subchondral IAOO can pose a therapeutic challenge. Our patients had an effective pain relief and return to activities with this treatment strategy.

Osteoid Osteoma at the Proximal Diaphysis of the Fifth Metatarsal

The foot is rarely the focus of osteoid osteoma, and only a few of those cases are related to the fifth metatarsal. The present case demonstrates that atypical symptoms with suspicious findings on plain radiographs that are not associated with trauma must be analyzed carefully to determine the nature of the lesion and perform the precise treatment to obtain and sustain the cure. A 29-year-old man presented to the outpatient clinic with a 2-year history of chronic pain in the lateral aspect of his left forefoot. The onset was not related to trauma, surgery, local infection, osteomyelitis, or another entity regarding the proximal fifth metatarsal. The patient noted that the pain was aggravated at night and typically subsided with the use of salicylates or other nonsteroidal anti-inflammatory drugs. Initial plain radiographs demonstrated cortical thickening and a lytic lesion at the proximal diaphysis of the fifth metatarsal. Because the pain relief was transient, we suspected an osteoid osteoma lesion, and subsequent magnetic resonance imaging manifested pathognomonic signs of subperiosteal osteoid osteoma. Diagnosis was followed by planning of the surgery that ended the patient's symptoms.

Intra-Articular Osteoid Osteoma as a Cause of Anteromedial Knee Pain

A 32-year-old male patient presented to our clinic with chronic left knee pain that was ongoing for about 1.5 years. The patient visited several times our clinic and the other clinics; conservative treatment (including rest, knee brace, and ice application with NSAIDs) was recommended by various different doctors. The anamnesis, physical examination, and plain radiography were nonspecific. Early MRI findings mislead us to believe it is bone marrow edema. One and half years with noneffective treatment, the knee pain persisted. At the latest visit intra-articular osteoid osteoma was suspected and the knee MRI with CT was employed. Even though the diagnosis of intra-articular osteoid osteoma often presents a challenge for the surgeons, with a present awareness of intra-articular osteoid osteomas which lack the characteristic sclerotic lesions and nidus on plain X-rays and the aid of multislice CT, a correct diagnosis which warrants proper treatment can be achieved. The possibility of osteoid osteomas, especially in young adults with persistent knee pain with unknown reasons that show normal plain radiographs results, must not be overlooked. The treatment method of these lesions should be customized depending on the location of the lesion, experience of the surgeon, and cost of method.

A misdiagnosed case of osteoid osteoma of the talus: a case report and literature review

BACKGROUND

Osteoid osteoma (OO) is a common benign bone tumour that is rarely found in the talus. Its nidus is difficult to detect on early imaging. The atypical symptoms of OO and the presence of concurrent trauma or sports injuries may lead to misdiagnosis and delayed treatment. We herein analyse a case of misdiagnosis of OO of the talus and discuss how to improve the early diagnosis of this rare lesion, thereby permitting rapid treatment.

CASE PRESENTATION

A 23-year-old man with a history of left ankle sprains and chronic pain was diagnosed with another ankle sprain and managed conservatively based on normal X-ray findings. After 1 year of recurring pain, he was diagnosed with ankle traumatic arthritis and underwent arthroscopic surgery. His preoperative ankle X-ray findings were still normal, and magnetic resonance imaging at that time demonstrated bone marrow oedema of the left talus. His symptoms reappeared shortly after surgery and progressively worsened. Magnetic resonance imaging performed 3 months after surgery demonstrated widespread bone marrow oedema of the talus. The patient presented to our hospital for pain assessment and was diagnosed with OO of the talus 3 years after his symptoms began. Preoperative computed tomography (CT) demonstrated a typical nidus of OO of the talus. After a second surgery, the patient's symptoms completely resolved, and pathologic examination confirmed that the lesion was OO. The patient recovered 3 months later and was able to walk normally.

CONCLUSIONS

OO of the ankle joint exhibits a progressive course and is difficult to diagnose at an early stage. Patients with OO of the talus often have atypical imaging findings, no signs of ankle instability, and no anterior talofibular ligament tenderness. CT is valuable for diagnosing OO, although multiple CT scans may be required to detect the nidus. Proper imaging helps doctors to achieve the correct diagnosis early in the disease course, significantly shortening the treatment cycle and improving the patient's quality of life.

Intra-articular osteoid osteoma as a differential diagnosis of diffuse mono-articular joint pain

Background

The aim of this retrospective study was to investigate the frequency of intra-articular osteoid osteoma (iaOO) in a large study cohort and to demonstrate its clinical relevance as an important differential diagnosis of non-specific mono-articular joint pain.

Methods

We searched the registry for bone tumours of the University Medical Centre Hamburg-Eppendorf for osteoid osteomas in the last 42 years. Herein, we present three selected iaOO which were detected in the three major weight-bearing joints. Computed tomography (CT) or magnetic resonance imaging (MRI) scans were performed for initial diagnosis.

Results

Out of a total of 367 osteoid osteomas, 19 (5.2 %) tumours were localized intra-articularly. In all three presented tumours, a history of severe mono-articular pain was reported; however, the mean time to correct diagnosis was delayed to 20.7 months. Clearly, the nidus seen in CT and MRI images in combination with inconsistent salicylate-responsive nocturnal pain led to the diagnosis of iaOO.

Conclusions

Rarely, osteoid osteoma can occur in an intra-articular location. In cases of diffuse mono-articular pain, iaOO should be considered both in large and smaller joints to avoid delays in diagnosis and therapy of this benign bone tumour.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-016-1313-3) contains supplementary material, which is available to authorized users.

Intra-articular osteoid osteoma in the proximal tibia and its imaging characteristics

Due to mostly non-specific clinical symptoms and variable appearance on magnetic resonance imaging (MRI), the diagnosis of an intra-articular osteoid osteoma (iaOO) is often delayed. We report the case of a 26-year-old male with an atypical clinical manifestation of an iaOO in the proximal tibia and its MRI specific characteristics of tumor progression. The patient presented to our clinic after receiving multiple unsuccessful conservative and surgical interventions due to anterior knee pain, which persisted for 12months. Prior to the correct diagnosis of iaOO manifestation, the patient was subjected to multiple steroid infiltrations and two arthroscopies including partial meniscal resection. Due to increasing complaints, meniscal transplantation, bone decompression and/or ACL reconstruction were recommended. Subsequent computer tomography (CT) scanning and successful test medication with salicylates (ASS) confirmed iaOO presentation. Only after arthroscopic tumor resection was the patient symptom free at three months of follow-up. The present description of MRI specific characteristics of iaOO progression has the potential to accelerate correct tumor detection in the future.

Osteoid osteoma of the foot and ankle--A systematic review

BACKGROUND

Osteoid osteomas are responsible for 10% of benign bone tumours. Treatment typically involves surgical excision or radio frequency ablation. The aim of this systematic review is to evaluate reported cases of foot and ankle osteoid osteomas.

METHODS

We conducted a systematic review of the literature using the online databases Medline and EMBASE. We included studies reporting osteoid osteoma diagnosed either radiologically or histologically.

RESULTS

94 studies were included reporting 223 cases; 70.5% were male, mean age was 23 years, 69% reported night pain and 72% responded to NSAIDs. The commonest affected bone was the talus. CT scan was the most useful radiological investigation and MRI missed the diagnosis in 34% of cases. The majority of patients underwent surgical excision but an increasing trend of ablation therapy was demonstrated.

CONCLUSIONS

A high index of suspicion based on salient history and appropriate imaging are essential for timely identification and treatment.

Hip arthroscopy for the management of osteoid osteoma of the acetabulum: a systematic review of the literature and case report

Background

Intra-articular osteoid osteoma (OO) causes irreversible joint damage. Its treatment of choice is radiofrequency ablation (RFA); however, some areas of the acetabulum are hard to access. Therefore, hip arthroscopy was used to treat this tumor. We aim to systematically review the literature with regards to arthroscopic management of acetabular OO, and to report a further case in which hip arthroscopy was used for treatment.

Methods

PubMed and EMBASE were searched for articles relevant to the arthroscopic management of acetabular OO on December 2, 2014. All articles published on and before that date were reviewed, and studies which met our pre-determined inclusion criteria were included. Articles screening and data abstraction were done by two reviewers independently. We also presented a 31-year-old man with acetabular OO who underwent hip arthroscopy for the management of his tumor after failing to respond to medications and computed tomography scan (CT)-guided RFA.

Results

The initial search revealed 14 studies, of which ten met our inclusion criteria. A total of ten patients underwent hip arthroscopy for the management of acetabular OO. Only two patients were females, and the patients' age ranged from 7 to 47 years. Two patients underwent arthroscopic guided-RFA of the lesion, while the rest underwent excision. The follow-up period ranged from 6 months to 2 years. Success rate was 100 %, and no recurrence was reported. Minor complications (transient impotence and perineal numbness) developed in one patient (10 %). Arthroscopic-guided RFA failed to eliminate the tumor in our additional case. A second trial of CT-guided RFA was successful in treating the patient's condition.

Conclusions

Hip arthroscopy is an effective and safe option for the management of acetabular OO, with success rate exceeding 90 %. Studies of higher level of evidence are required.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-015-0779-8) contains supplementary material, which is available to authorized users.

The valuation of using FDG PET-CT in detecting osteoid osteoma of the cervical spine

STUDY DESIGN

Osteoid osteomas (OOs) are bone tumors that rarely occur in the cervical spine. The current study is a retrospective analysis on 10 patients who were diagnosed with this rare spinal bone tumor. We have excised OOs of the cervical spine with the use of FDG Positron emission tomography-computed tomography (PET-CT) for preoperative diagnosis.

OBJECTIVE

With the help of the FDG PET-CT, we can confidently remove the nidus of the OOs, while minimize iatrogenic injury of the surrounding normal bone elements, and preserve the stability of the cervical spine.

SUMMARY OF BACKGROUND DATA

OO of the cervical spine is frequently located at the nerve root adjacent to the vertebral artery, spinal cord. PET-CT is a sensitive tool with applications in the detection of bone lesions, especially in patients with difficult diagnosis or continuing misdiagnosis of tumors.

MATERIALS AND METHODS

Ten patients (8 male and 2 female patients) underwent surgery for tumor removal using PET-CT in our department. Various diagnostic imaging modalities including x-ray, magnetic resonance imaging, CT, bone scintigraphy, and PET-CT were used. PET-CT scan results were measured using standard uptake value. (The size of the cases series was from 4×5 mm to 12×15 mm.) Pain was evaluated using the visual analogue score. Clinical outcome was evaluated immediately postoperatively and at a mean follow-up of 49.8±0.2 months (range, 7-92 mo).

RESULTS

All tumors were successfully diagnosed with the use of PET-CT. The average standard uptake value was 2.7±0.1 (range, 2.0-3.4). The nidus of the OO was detected and removed, and the peripheral elements were preserved. The visual analogue score was 8.1±0.1 preoperation, and it significantly decreased to 2.5±0.3 (P<0.01) postoperation and 0.2±0.1 (P<0.01) at the final visit. Immediately after surgery, the patients were relieved of their pain symptoms. There was no injury of the vertebral artery, leakage of cerebrospinal fluid, infectious complications, and neurological injury during the procedure.

CONCLUSIONS

It is valuable of using of PET-CT to diagnose OOs of the cervical vertebra. Subsequently, it is a good way that helps us in efficient removal of the OOs completely.

Atypical location of an osteoid osteoma with atypical anterior knee pain

INTRODUCTION

An osteoid osteoma is a painful tumor that most commonly affects the extra-articular parts of the long bones. An intra-articular location of an osteoid osteoma is rare. Various differential diagnoses may arise in connection with such an unusual location because it causes atypical clinical signs.

PRESENTATION OF CASE

A 24-year-old male developed pain in the central region of the right knee. Magnetic resonance imaging (MRI) showed no clear pathology in the knee joint. A technetium bone scan and computed tomography (CT) were then ordered and confirmed the presence of an osteoid osteoma in the knee joint. The patient was treated through an anteromedial approach to the knee, and the lesion was removed by excisional biopsy under fluoroscopy.

DISCUSSION

The diagnosis of intra-articular osteoid osteoma is challenging because the clinical presentation can be misleading. MRI is often requested as the first imaging method when dealing with knee symptoms, and radiologists are often unaware of the clinical presentation. Edema seen on MRI can be misleading with respect to the location of the nidus. CT is considered to be the best imaging method because it usually allows for clear visualization of the nidus. Different treatments have been proposed, ranging from open excision to arthroscopic resection.

CONCLUSION

Osteoid osteoma should be considered in young adult patients with chronic knee pain and no history of trauma.

Intra-articular osteoid osteoma mimicking juvenile arthritis

In case of intra-articular osteoid osteoma, misdiagnosis as juvenile arthritis may occur, delaying adequate treatment. We report cases of intra-articular osteoid osteomas in children that were misdiagnosed and initially inappropriately treated with intra-articular corticoid injection. Diagnosis of osteoid osteoma was finally given by CT-scan and appropriate treatment by radiofrequency ablation or surgical ablation was performed. Clinicians and radiologists should be aware of the potentially confusing clinical and imaging findings associated with intra-articular osteoid osteoma.

Intra-articular osteoid osteoma of the distal humerus: a diagnostic challenge

Osteoid osteoma rarely presents in an intra-articular or juxta-articular location, leading to synovitis and flexion deformity, which can easily mislead the diagnosis. We present a case of an intra-articular osteoid osteoma of the distal humerus in a 19-year-old woman with pain and flexion deformity of the elbow. Although radiographs were normal, a nidus was demonstrated on CT scan. Appropriate surgical treatment provided relief to the patient and the diagnosis was confirmed on histopathology. Thus, an intra-articular osteoid osteoma may be mistaken for more common causes of synovitis unless there is an index of suspicion and appropriate imaging is undertaken.

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.

Atypical osteoid osteomas

Osteoid osteoma is a very painful benign bone tumor that affects young adults. It is exceptional before 5 and after 30 years of age. It can be seen in any part of the skeleton. Presentation of the tumor may be intracortical, juxta-cortical or cancellous. In long bones, the tumor is frequently intracortical, and in the spine, it is usually located at the posterior elements. Osteoid osteomas having radiologic and clinical features other than classical presentation of osteoid osteoma are called atypical osteoid osteomas. Atypical osteoid osteomas are important because the diagnosis and treatment are often complicated in these cases. Misdiagnosis with prolonged impairment and sometimes overtreatment appears as a major problem concerning atypical osteoid osteomas. This paper gives brief general information about the classical presentation of osteoid osteoma, discusses the pathogenesis of the lesion and focuses on the clinical presentation, radiologic features and characteristics of atypical osteoid osteomas as well as their treatment modalities.

Juxta-articular osteoid osteoma of the talar neck: a case report

Juxta-articular osteoid osteomas of the ankle are rare and tend to have an atypical presentation. Because of the proximity to the joint, patients experience symptoms that may delay or mislead the diagnosis. This article presents a 33-year-old man with juxta-articular osteoid osteoma of the talar neck. The correct diagnosis was delayed for 2 years; the patient was initially misdiagnosed and treated for ankle sprain and anterior ankle impingement. Surgical excision of the lesion was performed with excellent results. Juxta-articular osteoid osteomas should be considered in the differential diagnosis of persistent ankle pain in teenagers and young adults who do not respond to treatment directed at more common conditions.

CT of the musculoskeletal system: what is left is the days of MRI?

Magnetic resonance imaging (MRI) plays a central role in the modern imaging of musculoskeletal disorders, due to its ability to produce multiplanar images and characterise soft tissues accurately. However, computed tomography (CT) still has an important role to play, not merely as an alternative to MRI, but as being the preferred imaging investigation in some situations. This article briefly reviews the history of CT technology, the technical factors involved and a number of current applications, as well as looking at future areas where CT may be employed. The advent of ever-increasing numbers of rows of detectors has opened up more possible uses for CT technology. However, diagnostic images may be obtained from CT systems with four rows of detectors or more, and their ability to produce near isotropic voxels and therefore multiplanar reformats.

Osteoid osteoma of the acetabulum: a case report

The acetabulum is a very rare location for osteoid osteoma. The diagnosis is difficult and usually delayed because the acetabulum is a rare site for this tumour and clinical signs are non-specific. Reported herein is the case of a 33-year-old woman who had non-specific pain and limitation of range of motion of the right hip. Bone scan, computed tomography and magnetic resonance imaging assessed the diagnosis of osteoid osteoma. Percutaneous resection guided by CTscan was performed and histology confirmed diagnosis. At follow-up, from two years, the patient remains asymptomatic. Osteoid osteoma of the acetabulum has been reported only in 13 cases. It is usually characterised by signs of synovitis. Recently, Computed Tomography guided percutaneous resection of OO has become the treatment of choice.

Radiofrequency ablation of intra-articular osteoid osteoma of the hip

Diagnosis and treatment of intra-articular osteoid osteoma is challenging. We present 16 patients with intra-articular osteoid osteomas of the hip treated with percutaneous radiofrequency ablation. Eight osteoid osteomas were located in the femoral head, six in the femoral neck, and two in the acetabulum. Three of the 16 patients had had an incorrect previous diagnosis. Percutaneous radiofrequency ablation was a clinical and technical success in all 16 patients. Within the first 24 h after the procedure, pain improved in all patients. Five patients had pain relief within the first 3 days after the procedure, nine patients within the first week and two patients within 2 weeks. Residual or recurrent symptoms were not reported by the last follow-up. At the 12-month follow-up, computed tomography and magnetic resonance imaging showed complete ossification and bone regeneration at the site of the lesion in three patients, partial ossification in six patients and no changes in seven patients. Computed tomography-guided percutaneous radiofrequency ablation is a simple, minimally invasive, safe and effective method for the treatment of most intra-articular osteoid osteomas.

Intra- and juxta-articular osteoid osteoma: a diagnostic challenge : misdiagnosis and successful treatment: a report of four cases

Osteoid osteoma is a benign tumour in young adults. The clinical manifestations are generally typical nocturnal pain that prevents sleep and that is alleviated with aspirin. When the typical clinical and radiological features are present, diagnosis is not difficult. Problems in the differential diagnosis may arise in connection with an unusual location. We report on the clinical features, radiographic and histopathological findings, treatment, and results of four patients who were managed for an intra- or juxta-articular osteoid osteoma at our medical centre between 2000 and 2002 and in whom the initial diagnosis was erroneous and delayed from 1 to 10 years. In order to remove these lesions, we performed a CT-guided en block retrograde resection under arthroscopic control for juxta-articular osteoid osteomas (knee) and an arthroscopy-assisted en block antegrade resection in two cases of intra-articular osteoid osteoma (elbow and shoulder). None of the osteoid osteomas recurred in the follow-up period, and each patient got relief from pain.

Imaging of intra-articular osteoid osteoma

Intra-articular osteoid osteoma accounts for approximately 13% of all osteoid osteomas and presents as a monoarthropathy. Radiographs commonly do not identify the nidus, and in this event, MRI is likely to be the next imaging investigation. MRI may show a variety of appearances depending upon the age of the lesion. This article illustrates the imaging features of intra-articular osteoid osteoma, with emphasis on MRI. CT remains the investigation of choice for identifying the nidus.

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.

Rapid development of severe osteoarthritis associated with osteoid osteoma in a young girl

In a 14-year-old girl with a 5 month history of left sided thigh pain, X-rays demonstrating osteoarthritis and a bone scintigraphy showing increased focal uptake in the femoral neck led to the diagnosis of an osteoid osteoma. The protuberant bone at the femoral neck was removed en-bloc and the diagnosis histologically confirmed. The synovium was extensively infiltrated with lymphocytes. Postoperatively the girl experienced neither the expected pain relief nor improvement of her hip function over the next 4 months. MRI and CT results indicated development of a severe osteoarthritis even though no residual lesion could be found.