Arthroscopic Excision of Intra-Articular Osteoid Osteoma of the Hip: A Case Series

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 Osteoma, a Diagnostic Problem: A Series of Atypical and Mimicking Presentations and Review of the Recent Literature

Osteoid osteoma (OO) is a common benign bone tumour, usually affecting young people. Typically, it is localised to the diaphyses or metaphyses of long bones. The classical manifestation includes distinctive night pain, almost always present, responding well to non-steroidal anti-inflammatory drugs, sometimes accompanied by complaints due to physical activity, and a typical picture on additional tests. A characteristic of osteoid osteoma is the presence of a nidus, usually visible on imaging tests. The nidus generally presents as a single, round lytic lesion up to 1 cm in diameter, surrounded by an area of reactive ossification. However, OO is a multifaceted neoplasm, and its diagnosis can cause numerous difficulties. OO can mimic multiple diseases and vice versa, which often leads to a prolonged diagnostic and therapeutic path and associated complications. There are few literature reviews about the differentiation and diagnostic difficulties of osteoid osteoma. Very effective therapies for this tumour are known, such as ablation and resection. Enhanced detection of osteoid osteoma could result in faster diagnosis and less suffering for the patient, avoidance of complications, and reduced costs of incorrect and prolonged treatment.

Posterior ankle arthroscopic treatment of a talar chondroblastoma with allograft and a platelet-rich plasma-fibrin glue: A case report and literature review

Talar chondroblastoma, which is a benign tumor of immature cartilage cells, is an uncommon but easily missed diagnosis of foot pain. Arthroscopic treatment for this condition is a safe, powerful, and promising technique with definitive advantages of visualization and minimal invasion. Here, we report a case of a talar chondroblastoma treated by posterior ankle arthroscopic curettage, allograft bone graft, and platelet-rich plasma-fibrin glue (PRP-FG) application.

Level of evidence

Case Report. Level IV.

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

Purpose

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

Methods

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

Results

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

Conclusion

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

Level of Evidence

Prognostic Level IV study.

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.

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.