Case report: Osteoid osteoma of the acetabulum treated with arthroscopy-assisted radiofrequency ablation

Intra-articular Osteoid Osteoma of the Intermediate Cuneiform Bone Causing Articular Degeneration: A Rare Case and Literature Review

Osteoid osteoma of the cuneiform bone is an exceedingly rare and easily missed cause of foot pain. The uncharacteristic and nonspecific radiographs of such intra-articular osteoid osteoma further increase difficulty in making the diagnosis. To date, there has been no description of intra-articular osteoid osteoma of the intermediate cuneiform bone causing articular degeneration in any published literatures. We present a case of intra-articular osteoid osteoma of the intermediate cuneiform bone causing articular degeneration, who underwent curettage, allograft bone graft, and navicular-cuneiform arthrodesis. The patient presented with radiographic bone union, full motor function recovery and pain-free at the 22-month follow-up. This report adds to the existing literature. Intra-articular osteoid osteoma of the intermediate cuneiform bone causing articular degeneration is an exceedingly rare and easily missed cause of foot pain. It proves a complicated and challenging task to identify intra-articular osteoid osteoma. Clinicians should be particularly careful not to exclude the possibility of arthritis and, thus, vigilant when choosing the surgical option.

Intra-articular hip joint osteoid osteoma: Challenging diagnosis and percutaneous radiofrequency ablation treatment

Atypical intra-articular osteoid osteoma can be difficult to diagnose and challenging to treat. We report a case of a right acetabular subchondral intra-articular osteoid osteoma in a young male patient which was initially diagnosed as femoroacetabular impingement due to its atypical clinical and radiological presentations. After fully working up the patient the lesion was successfully treated with percutaneous CT-guided low-power bipolar radiofrequency ablation using several per procedural articular cartilage thermal protective measures including intra-articular thermocouple, and continuous per procedural joint space cooling with Dextrose 5% solution. A precise RFA electrode placement, using the No-touch technique, and applying different passive and active thermal protective measures were helpful in avoiding collateral damage of the hip joint articular cartilages. atypical intra-articular osteoid osteomas necessitate pertinent correlation between the clinical and radiological presentations. As far as intra-articular or subchondral nidus ablation is concerned, thermal protective measures should be considered.

Hip arthroscopy has good clinical outcomes in the treatment of osteoid osteoma of the acetabulum

BACKGROUND

Osteoid osteoma (OO) of the acetabulum is a relatively rare disease. However, the the clinical outcomes of hip arthroscopy for treatment of OO of the acetabulum are still uncertain.

METHODS

We evaluated consecutive patients who were diagnosed with OO of the acetabulum and who underwent hip arthroscopy at our hospital between January 2013 and March 2020. All patients underwent a preoperative physical examination. Preoperative supine anteroposterior hip radiography, cross-table lateral radiographs, computed tomography (CT), and magnetic resonance imaging were performed in all patients. The alpha angle and lateral center-edge angle were measured before surgery. Supine anteroposterior hip radiography and CT were performed in all patients postoperatively. Preoperative patient-reported outcomes (PROs), including Visual Analog Scale (VAS), the International Hip Outcome Tool-12 (iHOT-12) and modified Harris Hip Score (mHHS), and PROs at final follow-up were evaluated.

RESULTS

A total of 6 patients (mean age, 18.7 years; age range, 6-31 years; 5 males and 1 females) were included in this study. The average follow-up period after surgery was 28.3 months (range, 6-90 months). Before surgery, the mean mHHS was 45.2 ± 10.5 (range, 33-56), the mean iHOT-12 was 33.3 ± 14.5 (range, 13-49), and mean VAS was 8.2 ± 1.0 (range, 7-9). At one month after surgery, mean mHHS was 78.7 ± 1.9 (range, 77-81), iHOT-12 was 71.0 ± 4.5 (range, 68-80), and mean VAS was 0. At the final post-operative follow-up, mean mHHS was 89.2 ± 2.1 (range, 86-91), iHOT-12 was 93.5 ± 5.0 (range, 88-98), and mean VAS was 0. All results, except VAS between one month after surgery and at final follow-up, demonstrated statistically significant improvement (P < 0.05). One patient underwent revision surgery.

CONCLUSIONS

Hip arthroscopy has good clinical outcomes in the treatment of OO of the acetabulum. Further study on the mechanism of secondary femoroacetabular impingement (FAI) caused by OO of the acetabulum is needed. More cases of arthroscopic excision and longer follow-up are also needed to better prove the clinical outcomes of hip arthroscopy for OO of the acetabulum.

Acetabula Osteoid Osteoma Mimicking Juvenile Idiopathic Arthritis and Chronic Recurrent Multifocal Osteomyelitis

Osteoid osteoma (OO) is a benign bone tumor that usually presents between 10 and 35 years of age. The metaphysis and diaphysis of the femur and tibia are the typical locations. The diagnosis is usually straightforward when images reveal a radiolucent nidus surrounded by reactive sclerosis. However, the diagnosis is more difficult when it occurs at atypical locations with nonspecific and misleading appearance on images. OO may mimic juvenile idiopathic arthritis (JIA), bone infection, or malignancy. We present a 14-year-old male with a 4-month history of left hip pain. His pain was worse with playing hockey and lacrosse and in the morning and sometimes woke him up at night. His examination was significant for pain with flexion and external rotation of the left hip and for mild limitation of full external rotation. Blood work revealed normal complete blood count, erythrocyte sedimentation rate, and C-reactive protein. Left hip X-ray was unremarkable. Left hip MR arthrogram showed marked edema of the medial and posterior walls of the left acetabulum. CT-guided biopsy of the left acetabulum showed unremarkable flow cytometry and chronic inflammatory component raising concern about chronic recurrent multifocal osteomyelitis (CRMO). Bone scan revealed focal increased uptake in the left acetabulum and no additional abnormality. Repeat MRI with intravenous contrast showed a left hip effusion, focal synovial enhancement in the medial left hip, and acetabula edema. The patient failed treatment for presumed JIA and CRMO with nonsteroidal anti-inflammatory drugs (NSAIDs), steroids, methotrexate, and adalimumab. CT scan of the left hip was performed for further evaluation of the bone and showed 11 × 6 mm low attenuation focus with subtle internal nidus in the posteromedial aspect of the acetabular rim, suggestive of intra-articular OO. Radiofrequency ablation was performed with no complications, and the left hip pain improved. The atypical location resulted in delay of diagnosis for 12 months after presentation. We highlight the diagnostic pitfalls observed in atypical OO locations and the difficulties this creates with making the diagnosis. OO mimicking JIA has previously been described. We submit CRMO as another differential diagnosis which may be mimicked and demonstrate the vital role of CT scan in the diagnosis.

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.

Arthroscopic removal of osteoid osteoma with gamma probe assistance in the hip joint

AIM

The aim was to present the surgical technique and clinical outcome in a series of patients treated with gamma-probe-assisted arthroscopic removal of osteoid osteoma in the hip joint.

METHODS

The case series consisted of 10 patients diagnosed with osteoid osteoma of the hip, who were treated by arthroscopic nidus removal. An endoscopic gamma probe was used intraoperatively to locate the nidus and to control the extent of its removal. Residual osteoma cavities were additionally treated with an arthroscopic radiofrequency ablator. Microfracturing was performed when the osteochondral defect was in the weight-bearing area and osteochondroplasty was done in cases of concomitant cam deformity. Nonarthritic Hip Score (NAHS), Tegner activity score, quality of life questionnaire (EQ-5D) and postoperative magnetic resonance imaging (MRI) were used for evaluation before and post-surgery, with a minimum follow-up of 2 years.

RESULTS

The relative reduction of the gamma irradiation count immediately after removal of the nidus was 44.9% (range 33.3-54.5%). Postoperatively, all patients experienced prompt pain relief and a significant improvement according to all patient reported outcomes. Control MRI revealed fibro-cartilaginous tissue repair of post-osteoma osteochondral defects in the weight-bearing area; 1 patient showed signs of early degeneration.

CONCLUSIONS

The results of this case series demonstrated the safety and high efficacy of gamma-probe-assisted arthroscopic removal of the osteoid osteoma from the hip joint. Endoscopic gamma probe was recognised as a very useful device for locating the nidus of the osteoid osteoma exactly and preventing incomplete or excessive removal of the bone.

Arthroscopic Management of Osteoid Osteoma of the Ankle Joint: A Systematic Review of the Literature

Osteoid osteomas (OOs) are rare benign bone tumors that may occur in various joints including the ankle. These tumors are generally removed via open surgical excision or radiofrequency ablation. However, when they occur intra-articularly, these treatments are more difficult to perform because of more difficult access and the increased risk of damaging articular cartilage. Therefore, some have advocated for the use of arthroscopy to treat these cases. This systematic review aims to investigate the safety and efficacy of arthroscopic treatment for intra-articular OO of the ankle. Using Medline and Embase, we systematically reviewed the literature as of May 31, 2017. All articles published on and before that date were reviewed by 2 independent reviewers. Seventeen articles containing a total of 27 cases were included in the review. Most reported cases were in the talar neck, followed by the distal tibia. Of all the cases, only 2 recurrences were reported (in the same patient), and no complications were reported. Therefore, these cases demonstrate arthroscopic excision of intra-articular OO of the ankle as a safe and effective alternative to open surgical excision and radiofrequency ablation, with a success rate of 96%. However, all articles found were case studies or small case series owing to the rarity of this disease. In the future, analyses of case series with larger case collections should be performed.

Osteoid Osteoma About the Hip in Children and Adolescents

BACKGROUND

The etiology of hip pain in pediatric and adolescent patients can be unclear. Osteoid osteoma (OO) about the hip in children has only been described in case reports or small studies. The present study assessed the clinical presentation and diagnostic course, imaging, and treatment approaches in a large cohort of pediatric cases of OO about the hip.

METHODS

Medical record and imaging results were reviewed for all cases of OO identified within or around the hip joint in patients <20 years old between January 1, 2003, and December 31, 2015, at a tertiary-care pediatric center. Demographic, clinical, and radiographic data were analyzed.

RESULTS

Fifty children and adolescents (52% female; mean age, 12.4 years; age range, 3 to 19 years) were identified. Night pain (90%) and symptom relief with nonsteroidal anti-inflammatory drugs (NSAIDs) (88%) were common clinical findings. Sclerosis/cortical thickening was visible in 58% of radiographs, although a radiolucent nidus was visible in only 42%. Diagnostic imaging findings included perilesional edema and a radiolucent nidus on 100% of available magnetic resonance imaging (MRI) and computed tomography (CT) scans, respectively. Initial alternative diagnoses were given in 23 cases (46%), the most common of which was femoroacetabular impingement (FAI). Delay in diagnosis of >6 months occurred in 43% of patients. Three patients underwent operative procedures for other hip diagnoses, but all had persistent postoperative pain until the OO was treated. Of the 41 patients (82%) who ultimately underwent radiofrequency ablation (RFA), 38 (93%) achieved complete post-RFA symptom resolution.

CONCLUSIONS

Initial misdiagnosis, the most common of which was FAI, and delayed correct diagnosis are common in pediatric OO about the hip. Presenting complaints were variable and nonspecific MRI findings were frequent. Night pain and relief with NSAIDs were present in the vast majority of cases. CT scans provided definitive diagnosis in all patients who received them. As increasing numbers of young, active patients are being evaluated for various causes of hip pain, such as FAI, OO should not be overlooked in the differential diagnosis.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Percutaneous radiofrequency ablation in osteoid osteoma: Tips and tricks in special scenarios

OBJECTIVES

To define specific characteristics of osteoid osteomas treated with radiofrequency ablation, that may benefit from special technical recommendations.

METHODS

Retrospective analysis of all radiofrequency ablations performed by our group from January 2001 to March 2015. A descriptive study was conducted. We compared our results with the available literature to determine the most frequent special scenarios.

RESULTS

207 radiofrequency ablations were performed in 200 patients. We defined the following scenarios: osteoid osteomas located in the spine, close to neurovacular structures, osteoid osteomas in small bones (hands and feet), intra-articular, deeply located or superficial and lesions with extensive periosteal reaction.

CONCLUSIONS

The scenarios defined required special considerations and technical variations. Implementing the different tips and tricks shown in the article, the most complex osteoid osteomas could be successfully ablated.

Clinical presentation of intra-articular osteoid osteoma of the hip and preliminary outcomes after arthroscopic resection: a case series

Intra-articular osteoid osteoma (IAOO) of the hip is a relatively rare diagnosis, but one that can closely mimic symptomatic presentation of femoroacetabular impingement (FAI). Although there are multiple case reports of osteoid osteoma (OO) in the hip, we present the largest case series of hip IAOO treated with hip arthroscopy and discuss limited patient-reported outcomes after treatment with hip arthroscopy. We retrospectively identified patients diagnosed with IAOO of the hip with confirmatory computed tomography, magnetic resonance imaging or biopsy diagnoses of OO. We analyzed lesion location, main presenting symptoms, symptom duration and treatment undertaken. For the patients who underwent hip arthroscopy for treatment of their IAOO, we reviewed patient-reported outcome scores when available.

Forty patients with confirmed IAOO were identified. Thirteen underwent excision with hip arthroscopy. The most common presenting symptom was groin pain. In limited patients who had pre- and post-operative outcome scores, we found significant improvements in modified Harris Hip Score (mHHS), Hip Outcome Score-Activity of Daily Living (HOS-ADL) and international Hip Outcomes Tool (iHot33) scores. Compared with patients undergoing hip arthroscopy for FAI alone, baseline mHHS, HOS-ADL, Hip Outcome Score–Sport-Specific Subscale and iHot33 scores were almost identical. We found that the presenting symptoms of hip IAOO closely mimic symptomatic FAI, including groin pain and anterior hip pain, so it is important to keep IAOO of the hip in the differential diagnosis of hip pain. Based on our experience, arthroscopy can be an effective treatment option for excision of intra-articular OO and is especially effective in patients with concomitant FAI in treating both pathologies.

Osteoid osteoma of the acetabulum: diagnosis and medical treatment

We describe the medical management of an acetabular osteoid osteoma in an 11-year-old girl. There was a 2-year delay until proper diagnosis of the patient's pathology was made. Accurate localization of the nidus in the subchondral bone, involving the cartilage, is difficult on the basis of plain radiographs. All imaging methods, including computed tomography, MRI, and bone scintigraphy, were used to confirm the diagnosis. We proposed medical treatment to avoid possible severe complications from surgical intervention. At the patient's latest follow-up visit, after 2 years of medical treatment with NSAIDs, there is complete healing of the osteoid osteoma and there is no sign of recurrence.

Osteoid osteoma of the acetabulum successfully treated with computed tomography-guided resection and ablation using a standard electrosurgical generator: a case report

Background

Osteoid osteoma accounts for approximately 10% of all benign bone tumors. The most common sites of osteoid osteoma are the subcortical shaft and metaphyses of long bones, but any other skeletal bone site can be involved. The acetabulum is a rare site according to past reports. This site presents challenges to optimal management because it is anatomically difficult to approach, and because its rarity leads to limited experience with therapeutic procedures. Here, we report for the first time a rare case of osteoid osteoma in the acetabulum that was successfully treated via resection of the nidus and ablation using a standard electrosurgical generator under computed tomographic guidance.

Case presentation

A 9-year-old Japanese girl presented at a clinic with left hip pain without apparent cause for 1 month. She was diagnosed as having coxitis simplex. However, her pain did not change for 1 year and she was admitted to another hospital where osteoid osteoma in her left acetabulum was suspected. She was then referred to our hospital approximately 1 year after first symptom presentation, where she presented with severe left hip pain and was completely unable to walk. Computed tomography examinations revealed a well-demarcated 5 mm mass with bone sclerosis in her left acetabulum. The mass was characterized by low intensity on T1 and high intensity on T2 magnetic resonance images. These findings were consistent with osteoid osteoma of left acetabulum. She underwent computed tomography-guided resection of nidus and ablation using a standard electrosurgical generator. A histological examination confirmed acetabular osteoid osteoma. Complete pain relief was achieved after the procedure and she experienced no complications. She could walk without any pain at the final follow-up 1 year post-treatment and no local recurrence was observed.

Conclusions

We successfully treated acetabulum osteoid osteoma without any symptom recurrence by computed tomography-guided resection and ablation using a standard electrosurgical generator. In addition, we preserved our patient’s sciatic nerve and triradiate cartilage. Our report provides evidence that a computed tomography-guided procedure should be considered the treatment of choice for osteoid osteoma of the acetabulum because it is a less invasive alternative to en bloc resection.

Hip arthroscopy for excision of osteoid osteoma and for the application of a collagen cartilage implant: Case report in a professional athlete, and literature review

BACKGROUND

Osteoid osteoma is an osteoblastic benign bone tumor usually affecting young adolescents. Intra-articular lesions are not common; usually the diagnosis is delayed. A lot of studies report difficulties and complications in the management of osteoid osteoma of the hip joint using imaging guided techniques or open surgical procedures. Only few published cases have described that it can be treated precisely using hip arthroscopy. Additionally, the use of hip arthroscopy to apply the Chondrofiller®, an acellular collagen matrix for the management of articular cartilage defects of the hip joint, has not yet been described.

CASE PRESENTATION

This report presents an osteoid osteoma of the femoral neck. A 20-year-old female professional basketball player presented with pain in the left groin since more than 12 months. On magnetic resonance and computed tomography imaging, an osteoid osteoma was suggested. The lesion was successfully removed using arthroscopy. During surgery, a concomitant grade 4 cartilage lesion on the femoral head was detected. For the treatment of this severe defect we used the Chondrofiller®, which is a new acellular collagen implant for auto-regeneration of articular cartilage. This matrix was filled into the prepared and dried defect using CO2 arthroscopy. After the hardening of the matrix the surgery was finished. The patient was pain free shortly after the operation and returned to sports within 16 weeks. Return to high-performance sports 8 months after surgery was without of any sign of complaints.

CONCLUSIONS

This article demonstrates that hip arthroscopy is a valuable tool for biopsy and excision of intra-articular osteoid osteoma affecting the hip joint, as well as for addressing other concomitant pathologies such as a severe synovitis or cartilage defects. CO2 arthroscopy provided good conditions for the drying and filling of the cartilage defect with the Chondrofiller®.

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.

What are the current indications for use of radiofrequency devices in hip arthroscopy? A systematic review

The role of radiofrequency energy (RFE) devices has been minimally studied in hip arthroscopy. The purpose of this study was to determine the role of RFE devices in hip arthroscopy through a systematic review of the literature. We searched the PubMed database using the following Medical Subject Heading terms: hip arthroscopy, hip radiofrequency, thermal capsulorrhaphy, thermal chondroplasty and radiofrequency debridement. Two authors independently reviewed the literature and included articles based on predetermined inclusion criteria. We excluded review, technique and experimental articles. After title and abstract review, we selected 293 articles for full-text review. Ten articles met the inclusion and exclusion criteria. For the included articles, a total of 305 hips underwent arthroscopy with concomitant RFE treatment at a mean age of 25.7 years. Eight articles presented patient-reported outcome (PRO) instruments, one study did not report an outcome instrument but utilized an evaluation of postoperative range of motion (ROM) and 1 year magnetic resonance image (MRI) and computed tomography (CT) imaging. The remaining article measured only the ROM pre- and postoperatively. Only one of the articles reviewed reported complications. Current evidence on the safety and indications for use of RFE devices in hip arthroscopy is insufficient. The literature shows mixed results regarding its use in hip arthroscopy. Although the use of thermal energy is not without risk, if used judiciously and appropriate precautions are taken to avoid damage to adjacent tissues, those devices can be useful for the treatment of certain intra-articular hip pathologies arthroscopically.

Osteoid osteoma of the glenoid: Arthroscopic treatment

Osteoid osteoma is a benign tumor that is rarely found in the scapula. We report a clinical case involving a 36-year-old female patient who suffered from progressive pain in her right shoulder for 1 year. This patient was initially diagnosed with impingement syndrome and was treated unsuccessfully with medication and physical therapy for approximately 2 months. Based on imaging exams, a juxta-articular osteoid osteoma of the glenoid was identified. The patient underwent a shoulder arthroscopy that included tumor removal and treatment of the resulting chondral lesion. At 6-, 12- and 36-month assessments, the patient was asymptomatic, with a normal range of motion and experienced a pain intensity corresponding to 0 points on the Visual Analog Scale (VAS) and 35 points on the University of California, Los Angeles (UCLA) Scale. A postoperative MRI indicated the absence of any residual tumor tissue or inflammatory signs. We believe that the approach described in this paper allows juxta-articular osteoid osteomas to be accessed in a minimally invasive manner and permits not only adequate resection but also the treatment of chondral lesions that could remain after tumor resection.

Arthroscopic excision of acetabular osteoid osteoma in a 7-year-old patient

The purpose of this study was to present the case report of a 7-year-old patient who was treated with hip arthroscopy for an acetabular osteoid osteoma. A 7-year-old patient was referred to our clinic with hip pain. In the assessment of the patient, an acetabular osteoid osteoma was detected in his right hip; it was adjacent to his triradiate cartilage. An arthroscopic surgery was planned as an alternative to open safe hip dislocation. The osteoid osteoma was completely removed with hip arthroscopy. Postoperative CT scanning and histopathological analysis confirmed the diagnosis. Exposure of the acetabulum can be problematic in paediatric patients due to the potential risks of open safe dislocation. Hip arthroscopy can safely be used for benign hip lesions in paediatric patients. Level of evidence Case report, Level V.

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.

Arthroscopic Excision of Acetabular Osteoid Osteoma: Computer Tomography-Guided Approach

Osteoid osteoma is a benign osteoblastic tumor that occurs in the subcortical shaft and metaphysis of the long bones of the lower extremities; however, intra-articular lesions are also possible. Intra-articular osteoid osteomas are rare, and clinical symptoms are often less specific and, thereby, may lead to misdiagnosis. The definitive treatment for osteoid osteoma is the excision of the nidus. We present the case of a 23-year-old man with a 4-year history of right anterior hip pain, subsequently diagnosed with a subarticular osteoid osteoma located in the right anterior acetabulum. Hip arthroscopic excision of the juxta-articular osteoid osteoma is presented as an effective treatment, with the advantage of less potential damage to normal bone and cartilage, as well as the additional benefits available with hip arthroscopy.

Arthroscopic treatment of recurrent acetabulum osteoid osteoma

In this case report, arthroscopic treatment of a recurrent osteoid osteoma in the posterior column of the pelvis extending to the acetabular fovea in a young adolescent is being presented.