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

Abstract

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.

Keywords: Osteoid osteoma (OO); children; delayed diagnosis; intra-articular.

Figure 1

Schematic diagram of the skeleton showing the relative frequency of OO lesions at various locations. OO, Osteoid osteoma.

Figure 2

A 14-year-old boy, complaining of right leg pain with activity, was admitted to the orthopedics department. The X-ray (A,B) was negative, CT scan (C) illustrating osteoproliferation near the femoral neck, coronal T2-weighted MRI (D) of the right hip showing synovitis and joint effusion, but no obvious lesion was seen. Bone scan (E) showing the abnormally increased radiotracer uptake. So, we performed the diagnostic surgery, and the pathological outcome was also positive. After the surgery, the pain was released. Sixteen months later, the same patient came to us again with the same complaints as before. Bone scan (J) showing the abnormally increased radiotracer uptake. The radiolucent nidus (white arrow) was seen in the Anteroposterior radiograph (F), axial CT scan (G), and MRI (H,I). After the surgery, the pathological outcome confirmed the OO diagnosis, and until now, the child resumed normal physical activities without recurrence. CT, computed tomography; MRI, magnetic resonance imaging; OO, Osteoid osteoma.