Osteoid Osteoma of the Calcaneus Mimicking Os Trigonum Syndrome: A Case Report

Intra-articular osteoid osteoma of the calcaneus: a case report and review

“…Osteoid osteoma in unusual locations may complicate the diagnostic process, with some patients being previously misdiagnosed as having os trigonum syndrome, calcaneal stress fracture, avulsion injury of the calcaneofibular ligament, subtalar arthritis, or ankle sprain [7], [8], [9], [10]. Many authors have reported cases of calcaneal osteoid osteoma being located in the intra-articular area, at which the tumor can be very difficult to diagnose [8], [9], [10], [11]. Typical findings in normal osteoid osteomas include a radiolucent lesion with a nidus appearance surrounded by bone scleroses [3], [5].…”

“…When calcaneal osteoid osteoma is accompanied by severe inflammatory changes, such as subtalar arthritis joint effusion and edema of the calcaneal bone marrow and surrounding soft tissue, the nidus may be masked impeding proper diagnosis. We have reviewed cases of calcaneal osteoid osteoma initially misdiagnosed based on MRI performed 3 months after the onset of symptoms [7], [9], [11]. Yang et al.…”

“…Moreover, after 5 months, the CT image demonstrated a bony lesion surrounded by sclerotic bone marrow, confirming a diagnosis of osteoid osteoma. Sanhudo [9] reported that 3 months after initial presentation, the MRI revealed increased signal changes around the large os trigonum, and 7 months after symptom development, it demonstrated a smaller lesion. In the present case, 4 months after symptom onset, the MRI only showed intramedullary bone marrow edema of the calcaneus and signal changes in the subtalar joint.…”

“…To the best of our knowledge, MRI scans in all cases of calcaneal osteoid osteoma reported till 3 months after the injury exhibited a nidus, with cases being treated only 3 months after initial presentation [7], [8], [9], [10], [11]. Therefore, we believe that calcaneal osteoid osteoma should be considered as a differential diagnosis in patients undergoing MRI 3 months after symptom presentation.…”

Cortical Osteoid Osteomas of the Calcaneus Managed by En Bloc Resection and Autogenous Iliac Bone Grafting

“…The most common sites of osteoid osteomas are the femur, especially the intertrochanteric or intracapsular regions of the hip, which are affected in two thirds of cases [2,3] the other common sites are the diaphyseal parts of the tibia and the humerus. This osteoid osteoma is not common in the foot and its incidence ranges from 4% to 16%, the preferred locations in the foot are the talus which ranges from 31% to 59% followed by the calcaneus which ranges from 12.5% to 22% of all osteoid osteomas of the foot [3][4][5]. There are frequent difficulties in the diagnosis and the localization of osteoid osteomas in the foot and also difficulties for the standard x-ray films to detect the tumor especially if there are extensive sclerosis in cortical lesion or arthrititic changes in subarticular regions in the small tarsal bone [3][4][5][6].…”