Osteoid Osteoma Research Articles

Primary osseous tumors of the orbit.

This review article focuses on the various primary osseous tumors of the orbit. Due to overlapping clinical, radiologic, and histologic features, differentiating these entities can pose significant challenges diagnostically. In this review, emphasis is placed on key distinguishing clinical, morphologic, immunophenotypic, and molecular characteristics. Also described are important prognostic details, recurrence risks, and the gold standard treatment methods for each entity. Relevant genetic syndrome associations are additionally covered. Orbital bone entities discussed include osteoma, osteoid osteoma, osteoblastoma, ossifying fibroma, fibrous dysplasia, aneurysmal bone cyst, osteosarcoma, Ewing sarcoma, and mesenchymal chondrosarcoma.

Operative and non-operative options for benign primary spine tumors

Benign primary spinal tumors (BPST) are rare entities with significant diagnostic and therapeutic challenges. These tumors can originate from the various mesenchymal tissues that compose the spinal column. They are typically classified using the Enneking or Weinstein-Boriani-Biagini (WBB) classifications, which guide surgical planning and intervention. The most frequent benign spinal tumors include osteoblastoma, osteoid osteoma, osteochondroma, giant cell tumors, aneurysmal bone cysts, hemangiomas, and Langerhans cell histiocytosis. Treatment options vary from nonoperative therapies such as analgesics, radiotherapy, and tumor ablation, to surgical interventions ranging from intralesional curettage to en bloc resection. The choice of treatment depends on factors such as tumor type, location, and potential for recurrence. A multidisciplinary approach, involving orthopedic surgeons, oncologists, and radiologists, is crucial for optimizing patient care. This review aims to provide concise information for the operative and nonoperative treatments of the most common extramedullary primary benign spinal tumors.

Unusual Presentation of Osteoid Osteoma with Exacerbating Pain during Menses

Osteoid osteomas (OO) are benign neoplasms commonly present during the second and third decade of life, showing a male predominance with classical nocturnal bone pain dramatically responding to nonsteroidal anti-inflammatory drugs. We report a rare OO in a young female who presented with right leg bone pain that was exacerbated during menstruation, a presentation that had never been reported before. The pain intensity increased and interfered with her daily activity, which urged for a careful evaluation by a computerized tomography scan showing OO signs. Surgical excision and histopathology confirmed OO. The patient’s pain drops down to zero on the visual analog scale. Two years after the surgery, she is well with no recurrence signs. A novel OO presentation may increase physician awareness of atypical presentation. A careful evaluation of a challenging presentation added to an imaging study may reveal the underlying cause and rule out other diagnostic dilemmas.

Transorbital Endoscopic Approach for Managing Challenging Frontal Sinus Lesions: Results and Operative Technique Description

Abstract Objective The aim of this study was to describe our experience using the transorbital endoscopic approach (TEA) in the frontal sinus and the step-by-step technique used. Materials and Methods We reviewed the charts from adult patients who underwent management of frontal sinus lesions with TEA performed from 2017 to 2022. Results Seven patients underwent eight surgeries for frontal sinus lesions using TEA in combination with the endoscopic transnasal approach (ETA), with the majority on the left side (5/8, 62.5%). The average age was 53.9 years, with six male patients and one female patient. Gross total resection (GTR) was achieved in all cases. The most common symptoms leading to surgery were headaches or a sensation of pressure in the forehead (5/8, 62.5%), followed by a decreased sense of smell (3/8, 37.5%), diplopia (3/8, 37.5%), proptosis (2/8, 20%), periorbital cellulitis (2/8, 20%), and decreased visual acuity (1/8, 12.5%). The most common etiology in this case series was mucocele (5/8, 62.5%), followed by osteoid osteoma (2/8, 20%), and inverted papilloma (1/8, 12.5%). The length of stay in all cases was 1 day. The most common complication was mild and transitory V1 numbness, which fully recovered after 6 months (5/8, 62.5%). The average follow-up period was 24.6 months (range of 3–48 months). Conclusion Transoral Endoscopic Approach (TEA) demonstrated being a valuable complement to ETA approaches for treating frontal sinus lesions, especially in challenging regions. The transorbital approach is feasible and can safely achieve GTR for a variety of pathologies while effectively controlling symptoms and resulting in a 1-day hospital stay.

Hip preservation in crisis: total hip replacement for osteoid osteoma-induced degeneration in a young adult

Osteoid osteoma is a small, benign tumor known for causing severe pain, especially at night. Intra-articular osteoid osteomas are rare and often misdiagnosed due to overlapping symptoms with other joint disorders like osteoarthritis or synovitis. These tumors require advanced imaging for accurate diagnosis and may necessitate surgical intervention when conservative treatments fail. A 22-year-old female presented with a four-year history of left hip and loin pain, initially treated with NSAIDs. Her symptoms progressively worsened, leading to imaging studies that revealed a sclerotic lesion in the hip joint. A biopsy confirmed osteoid osteoma, and due to the extent of joint damage, total hip replacement (THR) was performed. Postoperative recovery was excellent, with full functional restoration and no complications. This case illustrates the diagnostic and therapeutic challenges of intra-articular osteoid osteomas. THR proved to be a successful treatment in restoring function and alleviating pain, underscoring the need for early diagnosis and individualized surgical management in advanced cases.

Decreased volume of rectus femoris and iliocapsularis in patients with femoroacetabular impingement syndrome after primary hip arthroscopy

Purpose(1) to investigate the consecutive changes in hip muscle volume in patients with femoroacetabular impingement syndrome (FAIS) during the initial postoperative period, and (2) to determine the potential effect of the early changes in hip muscle volume on clinical outcomes.MethodsData between March 2021 and March 2022 was reviewed. Patients diagnosed with FAIS based on clinical symptoms and radiographic findings, and undergoing hip arthroscopic treatment were included. Exclusion criteria were incomplete MRI data, prior history of hip surgery, and concomitant hip conditions including hip osteoarthritis with a Tönnis grade > 1, avascular necrosis, Legg-Calvé-Perthes disease, osteoid osteoma, synovial chondromatosis, pigmented villonodular synovitis, and developmental dysplasia of the hip (DDH). MRI was performed preoperatively and 3, 6, 12-month postoperatively. Cross-sectional area (CSA) of hip muscles including rectus femoris (RF), iliocapsularis (IC), iliopsoas (IP), gluteus medius/minimus complex (G-med/min), and gluteus maximus (G-max) were collected on MRI. The CSA was corrected by body surface area (BSA). Preoperative and a minimum of 2-year postoperative patient-reported outcome (PRO) scores including Visual Analog pain Scale (VAS), modified Harris Hip Score (mHHS), and international Hip Outcome Tool, 12-component form (iHOT-12) were collected. A multivariate linear regression model was built to determine the influence of the potential factors on postoperative PROs.ResultsA total of 76 patients were included in the study. Compared to the preoperative level, decreased volume of RF and G-max, and increased IC/RF ratio were observed at postoperative 3 months (all with P < .05). Both G-med/min and G-max presented decreased volume at postoperative 6 months (all with P < .05). G-med/min presented decreased volume (P = .001) at postoperative 12 months. Changes in RF at postoperative 3 months and 12 months were positively related to improvement of iHOT-12 (Beta = 0.371, P = .012 and Beta = 0.330, P = .026, respectively). Changes in IC at postoperative 6-month was positively related to improvement of mHHS (Beta = 0.367, P = .027) and iHOT-12 (Beta = 0.315, P = .044).ConclusionDuring the initial first year following arthroscopic treatment for FAIS, decreased volume of the RF and gluteal muscles was observed. Early changes in volume of RF and IC were positively correlated to the improvement of minimum 2-year PROs.Level of evidenceLevel IV; case series.

A Rare Case of Osteoid Osteoma of the Medial Cuneiform Bone at Tibialis Anterior Insertion Confirmed by Bone Scan SPECT/CT.

A 34-year-old man presented with progressive foot pain that was initially on the medial soft tissue but eventually localized to the medial side of midfoot. Despite undergoing various imaging tests and conservative treatments over 2 years, the patient remained undiagnosed. After 6 months, soft tissue and bone involvement were observed on the medial cuneiform. A needle biopsy was inconclusive. Since bone tumor is rare in the medial cuneiform, the patient was referred to our department for 99mTc-MDP bone scan. The imaging and clinical findings suggested osteoid osteoma as the likely diagnosis, which was confirmed as intraarticular nidus under tibialis anterior attachment, after surgical resection and pathological examination.

A comprehensive MRI analysis of osteoid osteomas in patients with diverse radiological features across various regions.

Magnetic resonance imaging (MRI), which does not involve ionizing radiation, is the preferred imaging modality for diagnosing osteoid osteoma (OO), an ailment more common in children and young adults. This study aims to perform a literature review and delineate the MRI findings of OO lesions in patients exhibiting varying radiological features across different regions. A retrospective study included 63 patients diagnosed with OO through MRI, assessed independently by two blinded radiologists using both standard and dynamic contrast-enhanced MRI techniques. After excluding 7 patients with prior biopsy, surgery, or RFA, the study included 56 patients with 57 lesions. Of 57 lesions evaluated, 50 were in long, and 7 in flat bones. One patient presented with two separate nidi within the intertrochanteric region. Most of the lesions, 49 (86%), were extra-articular, while 8 (14%) were intra-articular. The nidus was intracortical in 45 (78.9%) patients, intramedullary in 5 (8.8%), subperiosteal in 5 (8.8%), and endosteal in 2 (3.5%). Average nidus diameter was 7.02 ± 2.64 mm (3-12.6 mm). Central nidal calcification was present in 68.4% (n = 39) cases. Contrast enhancement was intense at 90.5%, moderate at 9.5%. Reactive sclerosis around the nidus was severe (50.9%), moderate (22.8%), and mild (26.3%). Bone marrow edema was severe (70.2%), moderate (14.0%), and mild (15.8%). Soft tissue edema was identified in 77.2% of all lesions. To minimize delays in diagnosis and treatment, radiologists should become acquainted with the typical OO MRI findings and the atypical MRI findings that might be mistaken for other conditions.

Osseous tumors of the foot, ankle, and lower leg: a cross-sectional observational study analysing 288 cases

BackgroundOsseous tumors of the foot and ankle are rarely encountered in general orthopaedic practice and represent only 3 % of osseous neoplasms. It can be difficult to distinguish between benign and malignant lesions, leading to misdiagnosis. Delays in diagnosis are the main cause of litigation in sarcoma of the extremities. Poor understanding of how sarcomas present in this region can lead to inappropriate initial procedures, limiting options for limb salvage and increasing rates of local recurrence. Our aim is to improve understanding of these rare tumors to reduce misdiagnosis and decrease the occurrence of inappropriate or unwarranted procedures. MethodsWe retrospectively analysed a prospectively maintained database of 288 new referrals to the West of Scotland regional musculoskeletal oncology service for osseous lesions of the foot, ankle and lower leg over a 10-year period. An analysis of patient demographics, presentation, anatomical location, diagnosis, classification, management and outcomes was performed. ResultsOf all new referrals, 52.4 % were diagnosed with primary benign osseous tumors, 8.7 % with primary malignant osseous tumors, 9.7 % with metastatic osseous lesions, and 29.2 % pseudotumors. The most common primary benign tumor in our population was osteoid osteoma (18.5 %), primary malignant tumor was osteosarcoma (32 %) and metastatic osseous lesions were from small cell lung cancer primary (14.3 %). In the foot and ankle, malignant bone tumors most commonly presented in the distal tibia and fibula (20 %). Rest pain was the most common symptom at presentation in all groups, followed by swelling. The average duration of symptoms was 5 months for malignant lesions before primary referral. ConclusionBone tumors in the foot and ankle remain a diagnostic challenge. We hope to have increased understanding of these rare lesions and have recommended a management protocol in order to reduce the number of inappropriate procedures performed, optimising clinical outcomes and reducing the cost of litigation to healthcare services. Level of EvidenceLevel III- Cross-sectional observational study

Arthroscopic Chondral Nail Fixation for Treating Acetabular Cartilage Delamination Results in Improved Pain Relief at Minimum 2-year Follow-up in Patients with Femoroacetabular Impingement Syndrome: A Propensity-Matched Study

PurposeTo investigate the clinical outcomes following arthroscopic chondral nail fixation for acetabular cartilage delamination (ACD) in patients with femoroacetabular impingement syndrome (FAIS), and the presentation of ACD on MRI at follow-up. MethodsA retrospective review was performed between March 2021 and March 2022 at our institute. Patients undergoing primary hip arthroscopy for FAIS and diagnosed with ACD intraoperatively were included. Exclusion criteria were incomplete data or loss of minimum 2-year follow-up, and concomitant hip conditions including hip osteoarthritis with a Tönnis grade > 1, avascular necrosis, Legg-Calvé-Perthes disease, osteoid osteoma, synovial chondromatosis, pigmented villonodular synovitis, and developmental dysplasia of the hip (DDH). Patients who underwent chondral nail fixation were matched 1:1 with a control cohort of patients who only underwent simple debridement. Preoperative and minimum 2-year postoperative patient-reported outcome (PRO) scores including Visual Analog pain Scale (VAS), modified Harris Hip Score (mHHS), and percentage of achieving minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) were collected and compared. MRI was performed preoperatively and at final follow-up to assess ACD. ResultsFifty-eight patients were included in the study (29 patients in each group). Both groups demonstrated improved VAS and mHHS following surgery (all with P < .05). The chondral nail group demonstrated better postoperative VAS (P = .022) compared to the control group, while the postoperative mHHS was comparable between the two groups (P = .852). No significant difference was found in the achievement of MCID between the two groups (all with P > .05). More patients in the chondral nail group achieved PASS of VAS compared to the control group (75.9% vs 48.3%, P = .030). No patient underwent revision surgery or conversion to total hip arthroplasty (THA). The chondral nail group demonstrated significantly higher rate of ACD healing on MRI compared to the control group (P < .001). ConclusionPatients undergoing arthroscopic chondral nail fixation for treating ACD demonstrated significant pain relief, more achievement of PASS of VAS, and higher rate of ACD healing on MRI compared to those undergoing simple debridement. Level of EvidenceLevel III; retrospective cohort study.

Surgical results in cases of osteoid osteoma: a single-center retrospective study

Aims: This study aims to evaluate the clinical, radiological, and histological findings of patients who were treated for osteoid osteoma and discusses the diagnostic stages and surgical results of patients treated for osteoid osteoma. Methods: A retrospective examination was made of 38 patients who were treated in the Orthopedics and Traumatology Clinic of the 3rd Step University Hospital and diagnosed with osteoid osteoma between January 2010 and January 2023. The patients' demographic data and clinical, radiological, and histopathological evaluations were recorded. Results: In the surgical treatment of the 38 patients in this study, the nidus was excised with the en-bloc resection method or burr-down-assisted intralesional curettage. In the follow-up examination, a patient had a superficial wound site infection on the 14th day postoperatively, and daily dressings and antibiotic treatment were recommended. A significant decrease in pain was observed in 35 patients at the end of the month. In 2 patients, the pain had not recovered at the end of 6 months follow-up. After the second operation, all patients experienced significant relief from pain. Conclusion: Osteoid osteoma is a benign osteoblastic tumor primarily affecting young adults. Despite its benign nature, it often presents with localized nocturnal pain that is relieved by anti-inflammatory drugs. Treatment must be the complete removal of the nidus. Treatment options are evaluated according to the anatomical localization of the lesion.

Cryoablation of osteoid osteomas: Is it a valid treatment option?

Osteoid osteoma is a benign bone tumor with characteristic clinical symptomatology. The selected method for its treatment is percutaneous radiofrequency ablation. However, percutaneous cryoablation is an alternative method with certain advantages. To evaluate percutaneous computed tomography (CT)-guided cryoablation for the treatment of osteoid osteoma in young patients and adults. A total of 25 patients were treated with percutaneous CT- guided cryoablation for osteoid osteomas between October 2020 and March 2023 at a single institution. All patients were above 14-years-old (mean age, 24-years-old), and all procedures were performed under local anesthesia. Of the 25 patients, 8 were female and 17 were male. Tumor sites included the femur (n = 9), medial malleolus (n = 4), sacral ala (n = 4), facets (n = 4), humerus (n = 3), and tibia (n = 1). One cryoprobe was used in each procedure and, when possible, the lesion was covered by the ice-ball using an extraosseous position without penetrating the nidus. All necessary thermal protective techniques were used depending on the anatomical structure at risk. All patients treated had complete response (100% clinical success rate) starting on the day of the procedure. Technical success was achieved in all cases. Visual analog scale (VAS) scores at 1 year were 0, compared to a mean VAS score of 8.5 ± 1 (SD) before the procedure. No recurrences were reported at the 1-year follow-up and no complications were observed. In 11/25 cases, an extraosseous position of the cryoprobe was used with less procedural time achieving technical and clinical success and no complications with less patient discomfort. All patients were discharged from the hospital on the same day as the procedure. Cryoablation of osteoid osteomas is an efficacious and safe procedure with durable clinical results. Its greatest advantage is that the procedure can be performed under local anesthesia using an extraosseous position of the cryoprobe when possible.

Our Single Center Experience in Osteoid Osteoma Patients Treated with CT-Guided Percutaneous Radiofrequency Ablation Treatment and Follow-up.

Introduction Osteoid osteoma (OO) is a painful benign bone tumor. Typically, it causes pain that is most noticeable during the night, which is improved by nonsteroidal anti-inflammatory drugs. In the treatment of symptomatic lesions, open surgery for nidus removal is the gold standard. However, surgical technical difficulties and morbidities vary by location. Percutaneous radiofrequency ablation (RFA) therapy guided by computed tomography (CT) is now a popular treatment option for OO. This study aims to assess our single-center experience with the technique, complications, and procedure effectiveness. Materials and Methods The study included fifteen patients who were treated between 2017 and 2021. A retrospective analysis was carried out on archive images and file records. The lesions' location, nidus width, and affected area (cortical, medullary) were all recorded. The procedure and technical success, as well as postoperative complications and the need for repeat ablation, were all documented. Results A total of 20 patients, 18 men, and 2 women, were included in the study, and 12 of them were pediatric patients. The patients' mean age was 16.9±7.3 years old, and the mean nidus diameter was 7.1±8.7 mm. There were 13 cortical niduses, 2 intramedullary niduses, and 5 corticomedullary niduses. The lesions were in the femur (n=12), tibia (n=6), scapula (n=1), and vertebrae (n=1). Two recurrences (10%) were observed in our patients during the follow-up. Patient with a femoral OO, the pain started again 12 weeks after the procedure and we performed additional RFA. The patient with vertebral OO had fewer symptoms and full recovery was not achieved. Therefore, the vertebral OO was ablated again 4 months later, and clinical success was achieved. One patient had a minor burn at the entry site that went away on its own after a short period of time. Except for the patient who was scheduled for a repeat RFA, no recurrence has been observed so far. The primary and secondary success rates are, respectively, 90% (18/20) and 100% (20/20). Conclusion RFA has a high success rate in treating OO. The procedure failure and recurrence rates are low. There are possibilities for posttreatment pain relief, early discharge, and a quick return to daily life. For inappropriate lesion localization, the RFA process replaces surgical treatment. The procedure-related complication rate is low. On the other hand, the burn during the procedure can be a serious problem.

Advantages and disadvantages of methods of visualization in the surgical treatment of osteoid osteoma in children

Advantages and disadvantages of methods of visualization in the surgical treatment of osteoid osteoma in children

Meta-analysis of application of minimally-invasive ablation methods and classical surgical approach in osteoid osteoma and osteoblastoma

Abstract Osteoblastoma and osteoid osteoma are rare benign bone tumours, sometimes considered variations of the same pathologic process. However, they differ in location, incidence, age group, and size. The gold standard treatment is surgical excision for osteoblastoma and radiofrequency ablation for both. Minimally invasive techniques, including radiofrequency ablation, microwave ablations, cryoablation, ultrasound ablation, and laser ablation, are increasingly used. This meta-analysis aimed to review current treatments, focusing on minimally invasive methods versus traditional surgical excision. A data comparison of 17 original articles from the PubMed database (2014-2024) was conducted, examining treatment methods, patient numbers, success rates, pre/post-operative pain scores, and complication rates. New ablation methods achieve similar clinical results to traditional surgery for treating osteoid osteoma and osteoblastoma while minimizing invasiveness. Most procedures have technical success rates near 100%. Both invasive and non-invasive methods significantly reduce preoperative pain. Classical surgery has higher minor complication rates compared to minimally invasive treatments. Among ablation techniques, magnetic resonance guided focused ultrasound surgery is the least invasive, avoiding radiation and antibiotic-related complications. However, in ablation methods caution is needed to prevent thermal damage to nearby joints and nerves. Protective methods, such as skin protection, hydrodissection, gas dissection, and intraoperative neurostimulation, are recommended. New ablation methods provide less invasive alternatives to surgery, with high clinical and technical success rates and lower complication rates. Among these, magnetic resonance guided focused ultrasound surgery is the least invasive and most promising, though more clinical data is needed due to its recent development.

Novel Delivery of Cryoablation Through Transoral Surgical Approach for Atypical Presentation of Osteoid Osteoma of the C1 Lateral Mass: Technical Case Illustration

BACKGROUND AND IMPORTANCE: Neurosurgical literature rarely explores cases of osteoid osteomas of the atlas. Traditionally, neurosurgeons performed en bloc surgical resection for refractory osteoid osteomas in the subaxial and lumbar spine, but minimally invasive ablation therapies have gained favor. Complete lesioning of the nidus, either by surgical or minimally invasive therapies, produces curative results with recurrence only developing after partial lesioning. CLINICAL PRESENTATION: We discuss the case of a 16-year-old adolescent boy who presented with neck and occipital pain refractory to multimodal pain management. Prolonged workup demonstrated a subtle radiographic lesion of the left C1 lateral mass. Interventional radiologists attempted a posterior approach percutaneous computed tomography-guided radiofrequency ablation but aborted due to proximity of the vertebral artery. Surgeons then pursued an open transoral approach to provide a corridor for cyclical cryoablation therapy, which proceeded without complication. The patient was discharged on postoperative day one with remission of occipital pain at the 10-month follow-up. No clinical or radiographic evidence of instability appeared on postoperative cervical films. CONCLUSION: No reports exist in the literature of an osteoid osteoma of C1 treated by an open anterior approach and with cryoablation. The transoral approach is a safe, effective method to access ventral pathologies of C1. The transoral approach may minimize blood loss and reduce the risk of craniocervical instability, allowing for preserved cervical mobility and improved patient outcomes. Surgeons may especially consider cryoablation when the nidus is within proximity to critical neural structures.

Association between surgical results and recurrence in benign and intermediate osteogenic spine tumors – osteoid osteomas and osteoblastomas

Association between surgical results and recurrence in benign and intermediate osteogenic spine tumors – osteoid osteomas and osteoblastomas

Elongated morphology of osteoid osteoma is associated with radiofrequency ablation failure in children.

To compare the frequency of elongated morphology of osteoid osteoma (OO) in children compared to adolescents and to determine if this elongated morphology is associated with radiofrequency ablation treatment failure. Retrospective review of first-time CT-guided radiofrequency ablation performed for presumed OO in patients < 21years old between 1990 and 2023. Children were considered 0 to 10years old, and adolescents were considered 11 to 20years old. Treatment failure was considered symptomatic recurrence requiring follow-up intervention. The largest tumor dimensions in three orthogonal planes were measured using multiplanar reformatted technology. Maximum tumor dimension, tumor volume, and eccentricity index were calculated. Elongated morphology criteria were (a) largest dimension > 10mm and (b) eccentricity index ≥ 3. Lesion locations were recorded. Statistical analyses included the chi-square test, Fisher's exact test, nonparametric Wilcoxon rank-sum test, receiver operating characteristic analysis, and Spearman's nonparametric rank correlation. Of 366 included patients (median 15years, IQR 11-18years, 254 male), there were 86 (23.5%) children, 280 (76.5%) adolescents, and 24 (6.6%) cases of treatment failure. Elongated morphology was more common in children (19.7%) than adolescents (8.6%) (p = 0.004) and associated with younger age (p = 0.009). Elongated morphology was associated with treatment failure in children (p = 0.045) but not adolescents (p > .99) or all patients (p = 0.17). Treatment failure was not associated with age, largest dimension, eccentricity index, volume, or location. Elongated morphology of OO is associated with younger age and radiofrequency ablation treatment failure in children. Identifying this morphology may assist with counseling and treatment planning.

Ribbing disease of the femur: a rare entity.

Ribbing disease is a rare benign bone dysplasia characterized by progressive cortical thickening of the diaphyses of long bones in adult patients. The literature provides limited insight into its natural radiological progression and anatomical distribution. Single-bone involvement is particularly uncommon, with prior cases exclusively affecting the tibia. This case report outlines the unique presentation of Ribbing disease in a 20-year-old male, localized to the left femur. The patient's history revealed intermittent left thigh pain persisting for more than 2 years, with no identifiable triggers or relief factors. Early radiographic imaging revealed no significant abnormalities, but subsequent imaging, conducted 1 year after the initial presentation, revealed focal fusiform widening and cortical thickening of the mid-diaphysis of the left femur. MRI further revealed circumferential cortical thickening with bone marrow edema, corroborated by CT, which revealed cortical thickening with near-complete obliteration of the intramedullary cavity. The patient was managed with nonsteroidal anti-inflammatory drugs and activity modifications. Misinterpretation of the radiographic findings of the osteoid osteoma led the patient to undergo radiofrequency ablation. This case highlights the challenges in diagnosing Ribbing disease and emphasizes the importance of considering it in the differential diagnosis of chronic limb pain. Continued reporting of cases contributes to enhancing our understanding and management of this rare skeletal dysplasia.

Intra-articular Osteoid Osteomas: Imaging Manifestations and Mimics.

Osteoid osteoma (OO) is the third most prevalent benign bone neoplasm in children. Although it predominantly affects the diaphysis of long bones, OO can assume an intra-articular location in the epiphysis or the intracapsular portions of bones. The most common location of intra-articular OO is the hip joint. The presentation of intra-articular OOs often poses a diagnostic enigma, both from clinical and radiologic perspectives. Initial symptoms are often vague and nonspecific, characterized by joint pain, stiffness, and limited range of motion, which frequently contributes to a delayed diagnosis. Radiographic findings range from normal to a subtle sclerotic focus, which may or may not have a lucent nidus. In contrast to their extra-articular counterparts, intra-articular lesions have distinct features at MRI, including synovitis, joint effusion, and bone marrow edema-like signal intensity. While CT remains the standard for identifying the nidus, even CT may be inadequate in visualizing it in some cases, necessitating the use of bone scintigraphy or fluorine 18-labeled sodium fluoride PET/CT for definitive diagnosis. Radiologists frequently play a pivotal role in suggesting this diagnosis. However, familiarity with the unique imaging attributes of intra-articular OO is key to this endeavor. Awareness of these distinctive imaging findings of intra-articular OO is crucial for avoiding diagnostic delay, ensuring timely intervention, and preventing unnecessary procedures or surgeries resulting from a misdiagnosis. The authors highlight and illustrate the different manifestations of intra-articular OO as compared with the more common extra-articular lesions with respect to clinical presentation and imaging findings. ©RSNA, 2024 Supplemental material is available for this article.