Osteoid Osteoma About the Hip in Children and Adolescents

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.

Osteoid osteomas of the hip: a well-recognized entity with a proclivity for misdiagnosis

OBJECTIVES

The diagnosis of osteoid osteomas (OO) about the hip can be challenging as presenting symptoms can mimic other, more common, periarticular pathologies. Our aims were to identify the most common misdiagnoses and treatments, mean delay in diagnosis, characteristic imaging features and provide tips for avoiding diagnostic imaging pitfalls for patients with OO of the hip.

METHODS

We identified 33 patients (34 tumors) with OO about the hip who were referred for radiofrequency ablation between 1998 and 2020. Imaging studies reviewed included radiographs (n = 29), CT (n = 34), and MRI (n = 26).

RESULTS

The most common initial diagnoses were femoral neck stress fracture (n = 8), femoroacetabular impingement (FAI) (n = 7), and malignant tumor or infection (n = 4). The mean time from symptom onset to diagnosis of OO was 15 months (range, 0.4-84). The mean time from initial incorrect diagnosis to OO diagnosis was 9 months (range, 0-46).

CONCLUSIONS

The diagnosis of OO of the hip is challenging, with up to 70% of cases initially misdiagnosed as a femoral neck stress fracture, FAI, bone tumor, or other joint pathology in our series. Consideration of OO in the differential diagnosis of hip pain in adolescent patients and awareness of the characteristic imaging findings are critical for making an accurate diagnosis.

KEY POINTS

• The diagnosis of osteoid osteoma of the hip can be challenging, as demonstrated by long delays in time to initial diagnosis and high rates of misdiagnoses which can lead to inappropriate interventions. • Familiarity with the spectrum of imaging features of OO, especially on MRI, is imperative given the increase in the utilization of this modality for the evaluation of young patients with hip pain and FAI. • Consideration of OO in the differential diagnosis of hip pain in adolescent patients and awareness of the characteristic imaging findings, including bone marrow edema and the utility of CT, are critical for making a timely and accurate diagnosis.

Intraoperative three-dimensional navigation for surgical treatment of osteoid osteoma in the upper extremity: A series of 19 cases

The surgical treatment for osteoid osteoma (OO) in the upper extremity is challenging due to the difficulty in locating the lesion and the crowding of sensitive structures within the anatomy. This study aimed to describe the outcomes of navigated minimally invasive radiofrequency ablation and those of navigated mini open-intralesional curettage in treating these lesions. Nineteen consecutive patients with OO in the upper limb who underwent navigated surgery were included. The average QuickDASH and Numeric Pain Rating Scale improved from 62.2 ± 23.7 to 11.7 ± 16.9 and from 8.1 ± 1.6 to 0.5 ± 1.8, respectively (p < .01 each) following the procedure. Two complications were recorded: one patient had persistent radial nerve palsy, and one patient had transient partial radial nerve weakness. In conclusion, navigation is an important tool in the surgical treatment of OO in the upper limb. A mini open approach to identify and protect neurovascular structures is recommended.

Evaluation of paediatric hip pain

Hip pain in a child can pose a diagnostic conundrum. In most cases, the cause of a painful hip is often attributed to trauma, but a number of these cases will be atraumatic. The main entities to consider are inflammatory, infective and neoplastic causes. Pathologies such as avascular necrosis and slipped upper femoral epiphysis can also present in a similar manner. A detailed history and clinical examination are crucial in narrowing down the differential diagnosis. In addition, understanding the most appropriate imaging modalities and the characteristic radiological findings is key in ensuring timely treatment and management. This article reviews the various disease processes in children who present with hip pain and outlines the most appropriate assessment and imaging modalities that will aid diagnosis.

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.

Intraoperative three-dimensional navigation for surgical treatment of osteoid osteoma in the foot and ankle - A series of 14 cases

BACKGROUND

The surgical treatment for osteoid osteoma (OO) in the foot and ankle is challenging. It is difficult to locate the lesion and the anatomy is crowded by sensitive structures. The purpose of this study was to describe the outcomes of navigated mini open-intralesional curettage (NMIC) or navigated minimally invasive radiofrequency ablation (NMRFA) in treating these lesions.

METHODS

All patients who underwent surgery for OO in the foot and ankle between 2015 and 2020 were included. O-arm navigation was used in All procedures. The choice of NMIC versus NMRFA was made by the surgeon according to the location of the lesion and its proximity to sensitive anatomic structures.

RESULTS

Fourteen patients were included. Ten were operated by NMRFA and 4 by NMIC. All patients' symptoms related to OO resolved following a single procedure. Average AOFAS score increased by 18.7 (P < .001). Three patients had the following complications: pathologic fracture, superficial infection and transient deep peroneal nerve sensory loss.

CONCLUSION

Navigated surgical treatment of OO in the foot and ankle is accurate, efficient and safe.

An Overlooked Entity in Diagnosing Hip Pain with Neuropathy in an Athletic Young Adult: A Case Report

Hip pain is frequently encountered in the athletic community. Femoro-acetabular impingement (FAI) is a common cause of hip pain in young adults. However, it is important to appreciate the uncommon diagnosis and the role of imaging for unexplained hip pain. The pathology behind a posterior hip pain is often misdiagnosed as the cause of hip pain is non-specific, extensive and elusive. We managed to detect the pathology through magnetic resonance arthrography (MRA) of hip with gadolinium enhancement after a series of inconclusive history, physical examination and imaging findings were completed. This particular case vignettes an overlooked osteoid osteoma that leads to the delay in diagnosis and increase morbidity.

A CT-free protocol to treat osteoid osteoma of the hip region in childhood and adolescence by percutaneous drilling and by hip arthroscopy

INTRODUCTION

It is often difficult to clinically and radiologically diagnose intra-articular osteoid osteomas and osteoid osteomas of the hip joint. Treatment can also be difficult due to complex locational relationships. CT-guided radiofrequency ablation is currently the standard form of treatment.In this paper we report on a minimally-invasive concept for treating osteoid osteomas near the hip joint in children and adolescents which does not involve using computed tomography.

MATERIAL AND METHOD

10 patients with an average age of 12.1 years underwent treatment for osteoid osteomas in the hip joint region. The diagnosis was made using a contrast-enhanced MRI. The osteoid osteomas were marked percutaneously using x-ray and MRI guidance. MRI-guided drilling/curettage was performed in 4 cases and arthroscopic resection in 6 cases.

RESULTS

All lesions were successfully treated using the MRI-guided method. All patients were free of pain after the treatment. There was no instance of recurrence during the follow-up period, which averaged 10 months. The effective dose for marking the lesion was between 0.0186 mSv and 0.342 mSV (mean 0.084 mSV).

CONCLUSIONS

Our MRI diagnostics protocol, the MRI-guided drilling and the minimally invasive hip arthroscopy represent an alternative to CT-guided radiofrequency ablation in the treatment of osteoid osteomas. Radiation exposure can thereby be significantly reduced. Hip arthroscopy can also be used to treat secondary pathologies such as femoroacetabular impingement.

Intra- and juxta-articular osteoid osteoma in children and adolescents

BACKGROUND

Osteoid osteoma (OO) is a common benign tumor in children and adolescents, but intra-and juxta-articular OO is rare and difficult to diagnose. The purpose of this study is to investigate the distinctions between intra- and juxta-articular OO, trying to avoid delaying diagnosis and optimize treatment strategies.

METHODS

Thirty patients diagnosed with OO in the intra- and juxta joint at our institution who underwent surgical resection were included. Clinical and epidemiological factors, preoperative radiograph parameters, including computed tomography (CT), magnetic resonance imaging (MRI), and bone scan, were documented. The outcomes of the involved extremity were evaluated at the final follow-up.

RESULTS

Mean age at diagnosis, interval time, and follow-up time was 8.37±3.79 years old, 4.67±5.88 months, 3.57±2.18 years, respectively. Factors identified to be significantly associated with intra- and juxta-articular OO including pain with activity (P=0.004) and abnormal range of motion (P=0.00). The factor of abnormal range of motion (P=0.03) also influenced the existence of complications. Six children had a secondary operation to cure the recurrence.

CONCLUSIONS

It is essential for clinicians and radiologists to be aware of the atypical clinical and radiographic features of intra- and juxta-articular OO, as the delayed diagnosis can lead to unnecessary pain and further complications after surgeries. The pain with activity and abnormal range of motion is helpful to identify the location of OO. The persistently abnormal range of motion also significantly leads to complications. The open surgeries to resect the nidus in juxta-articular OO were effective.

Osteoid Osteoma of the Proximal Femur: Pitfalls in Diagnosis and Performance of Open Surgical Resection

Aims

Proximal femoral osteoid osteoma (OO) is extremely easy to be misdiagnosed or missed. The purpose of this study was to retrospectively analyze the clinical data of patients with proximal femoral OO in order to determine the clinical manifestation and imaging characteristics of the disease, so as to provide help for the preoperative diagnosis and clinical treatment of proximal femoral OO.

Methods

This was a retrospective study involving 35 patients with proximal femoral OO admitted into our hospital from January 2015 to January 2021. The baseline characteristics of the participants included; 24 males and 11 females, aged between 13 and 25 (mean 16.2) years old, and the course of the disease was 1 to 14 (mean 6.3) months. We used previous medical experience records of the patients to analyze for the causes of misdiagnosis. Moreover, we compared the difference between preoperative and postoperative treatment practices in alleviating pain in OO patients and restoring hip function. Follow-ups were carried out regularly, and patients advised to avoid strenuous exercises for 3 months.

Results

We followed up 35 patients (25 intercortical, 4 sub-periosteal, and 6 medullary) for an average of 41.4 months. We found that 15 patients (42.9%) had been misdiagnosed of synovitis, perthes disease, osteomyelitis, intra-articular infection, joint tuberculosis and hip impingement syndrome, whose average time from symptoms to diagnosis were 6.3 months. Postoperative pain score and joint function score improved significantly compared with preoperative, and complications were rare.

Conclusion

Open surgical resection constitutes an effective treatment for proximal femoral OO by accurately and completely removing the nidus. Wrong choice of examination, and the complexity and diversity of clinical manifestations constitutes the main reasons for the misdiagnosis of proximal femoral OO.

Differential diagnosis of hip pain in children referred to a specialist bone tumour service

OBJECTIVE

To determine the differential diagnosis of bone lesions causing hip pain in children and the association between radiographic features of aggression and MRI appearances with final diagnosis.

METHODS

Retrospective review of children with hip pain referred to a specialist musculoskeletal oncology service between September 2018 and December 2020. Patient demographics, lesion location, the radiographic and MRI features, and the final diagnosis, which was made either by image-guided biopsy, surgical curettage or based on typical imaging features were recorded. Statistical analysis examined the association between the Lodwick-Madewell score (determined from available radiographs) and MRI findings with final diagnosis.

RESULTS

Fifty-nine patients were included, 40 males and 19 females with mean age 10.9 years, (range 3-16 years). Final diagnoses were based on histology in 24 (40.7%) cases and imaging in 35 (59.3%) cases. Eighteen lesions (30.5%) were classed as non-neoplastic, 31 (52.5%) as benign and 10 (16.9%) as malignant, of which four were primary bone sarcomas. There was a significant association between the Lodwick-Madewell score and final diagnosis (p < 0.001). On MRI, bone marrow oedema, presence of a focal lesion, bone expansion and the presence of an extraosseous mass were all significantly associated with final diagnostic classification.

CONCLUSION

The differential diagnosis of hip pain in children presenting to a bone tumour service is wide. Most cases are due to benign or non-neoplastic conditions, with only 10 out of 59 children having a malignant lesion. Radiography complemented by MRI plays a major role in differentiating non-neoplastic, benign neoplastic and malignant lesions and in determining the requirement for needle biopsy.

ADVANCES IN KNOWLEDGE

This is the first study to consider how imaging features relate to diagnosis in suspected paediatric hip tumours. Use of this information can help in determining which cases should undergo needle biopsy.

Comparison of arthroscopy versus percutaneous radiofrequency thermal ablation for the management of intra- and juxta-articular elbow osteoid osteoma: case series and a literature review

BACKGROUND

Today, intra-articular and juxta-articular osteoid osteomas are treated with arthroscopy and radiofrequency thermal ablation. However, for the case of an elbow joint, arguments are made for the use of a minimally invasive technique to be the optimal choice. This study aims to analyse our experiences of arthroscopically treated elbow osteoid osteomas and to compare it with the published results of both techniques.

METHODS

The retrospective study analyses the patients who underwent elbow arthroscopy ablation of an elbow osteoid osteoma at a single institution from January 2014 until March 2020. Clinical and diagnostic features, success and treatment failure rates, complications and tumour recurrence rates were all compared to 13 studies of intra-articular elbow osteoid osteoma arthroscopic ablation and 15 studies involving radiofrequency thermal ablation of intra-articular osteoid osteoma within different joints.

RESULTS

Four males and two females, with a mean age of 19.3 years, were encompassed. All the patients had immediate postoperative pain relief and improved range of motion. No tumour recurrences were observed during a median of 21.7 months. The literature review yielded 86.4% success rate, 68.2% successful biopsies, one minor complication and no recurrences following the arthroscopic ablation of an elbow osteoid osteoma; while radiofrequency thermal ablation of an intra-articular elbow osteoid osteoma yielded 96.3% success rate, 33.3% successful biopsies, no complications and 3.7% recurrence rate.

CONCLUSIONS

Our results are consistent with the published literature proving that arthroscopic ablation is an efficient method with low treatment failure rates and no recurrences in treating intra- and juxta-articular elbow osteoid osteomas. Advantages of arthroscopic ablation stem from the ability to visualise and safely deal with the lesion and the joint's reactive changes resulting in high biopsy rates, no recurrences and better postoperative elbow's range of motion. Still, the technique selection should be personalised considering the medical expertise of every institution.

Which is the optimal minimally invasive treatment for osteoid osteoma of the hip? A systematic review and proportional meta-analysis

BACKGROUND

Osteoid osteomata comprise approximately 10% of benign bone tumours, with 20% of them being located in the proximal femur and 1-3% in the pelvis. In this meta-analysis, we sought to investigate positive and negative outcomes relating to minimally invasive surgery (MIS), which has superseded open resection and conservative measures over the last decades.

METHODS

We searched the PubMed, CENTRAL and grey literature for completed studies published until 10 August 2020. Articles with a minimum of ten patients diagnosed with osteoid osteomata of the proximal femur and/or acetabulum were included. Primary outcomes were success rates, complications and recurrences following treatment. Delays in diagnosis were also recorded. We conducted random effects meta-analysis of success rates for MIS modalities using MedCalc statistical software. Quality was assessed with a modified Delphi checklist.

RESULTS

Sixteen case-series were identified. Success rates for computed-tomography (CT)-guided radiofrequency ablation (RFA), CT-guided percutaneous resection drilling and arthroscopic resection were 98.2% (95% CI 95.8-99.5), p = 0.47; 91.5% (95% CI 81.1-97.9), p = 0.06; and 98% (95% CI 89.3-99.7), p = 0.95, respectively. Both RFA and percutaneous drilling resection were associated with two iatrogenic femoral fractures. Arthroscopic removal was not associated with any complications. Definitive diagnosis was established at least six months after symptom onset in up to 43% of patients.

CONCLUSIONS

RFA could be the most effective treatment options for patients suffering from osteoid osteomata of the hip. Arthroscopy could be potentially as effective as RFA as long as further large-scale studies confirm its efficacy and safety. Reported complications stemming from these modalities were sparse in nature. In order to avoid inordinate diagnostic delays, a high index of suspicion and low threshold for CT scan investigation is required.

Benign Bone Tumors: An Overview of What We Know Today

Nonmalignant bone tumors represent a wide variety of different entities but maintain many common features. They usually affect young patients, and most can be diagnosed through imaging exams. Often asymptomatic, they can be discovered incidentally. Due to their similarities, these tumors may be challenging to diagnose and differentiate between each other, thus the need for a complete and clear description of their main characteristics. The aim of this review is to give a picture of the benign bone tumors that clinicians can encounter more frequently in their everyday work.

OUP accepted manuscript

Osteoid osteoma located on the hip joint presents with atypical symptoms that can be misdiagnosed or missed. Multiple image studies can be made for diagnosis but OO should be suspected to properly choose the right one. Percutaneous resection with CT guidance is a reproducible and accurate technique with the appropriate tools and a specialist team to obtain optimal results.

Osteoid Osteoma of the Scapular Neck: A Cause of Long-lasting Unexplained Pain

Introduction:

Osteoid osteoma (OO) is a common tumor of the diaphysis of long bone, where the reported incidence is up 10% of all benign bone tumors. Its presence in flat bone is seldom mentioned in literature and can be misleading when the bone involved is in proximity to a zone of wide variety of possible pathology. We report a case of a young patient with OO in a very rare location of the body –the scapular neck – that was misdiagnosed for a long period of time before receiving adequate therapy.

Case Report:

A 20-year-old female patient presented to the clinic with chronic left shoulder pain. During the past 2 years, she received medical and physical therapy, to deal with different diagnosis such as cervical spine pathology, muscular spasm, and rotator cuff disease. However, she did not improve. At time of presentation to our clinic, radiographs of the shoulder were done and turned to be inconclusively normal. After negative magnetic resonance imaging of the cervical spine, a computed tomography scan of the shoulder was done and showed a round well-defined lesion localized in the scapular neck with a focal lucent nidus within surrounding sclerotic reactive bone measuring 8.5 mm in largest diameter, compatible with OO. Bone scan showed increased uptake. The patient was given aspirin in an intention to test and treat. The patient had dramatic pain relieve at first, which confirmed the diagnosis of OO. But then, pain became unremitting, so a decision was made for radiofrequency ablation of the lesion which gave excellent results.

Conclusion:

OO is a common benign neoplasm with high variable clinical picture and anatomic localization. Despite being more common in long bone, flat bone OO localization should be always kept in mind. Careful history and physical examination should be done for each patient presenting with unexplained pain; night pain should always raise suspicion of this condition. Radiographs are not always conclusive, and the patient with high suspicion of this condition should undergo more investigation to make the diagnosis.

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.

Cartilage-Preserving Arthroscopic-Assisted Radiofrequency Ablation of Periacetabular Osteoid Osteoma in a Young Adult Hip

Osteoid osteomas are benign bone lesions that commonly occur in the lower extremities and spine, with the radiographic evidence of a central nidus surrounded by circumferential reactive bone. Although nonsteroidal anti-inflammatory drugs can provide symptomatic relief and are used as an important diagnostic tool, surgical intervention is the definitive treatment. Arthroscopic-assisted radiofrequency ablation has been shown to be an effective technique to directly visualize and treat the lesion while minimizing damage to the articular cartilage.

Osteoid osteoma of the hip: imaging features

Osteoid osteoma (OO), a small bone tumor relatively common in young subjects, frequently involves the hip. In addition to typical findings, we emphasize unsuspected clinical and imaging features including painless OO causing limping gait, non-visibility of totally mineralized nidus, absence of hyperostosis or adjacent edema, and recurrence at distance from the initial location. We also discuss the option of medical treatment for some cases of deep hip locations.