case_images: PMC7476701_01
case_images: (a-d) Anteroposterior and lateral radiographs of the knee in a young male with anterior knee pain. No gross abnormality was detectable. (c) T2-weighted sagittal magnetic resonance imaging (MRI) section showing patellar edema. (d) T2-weighted axial MRI section showing a hypointense punctate lesion surrounded by a small hyperintense zone near the medial border of patella, close to its articular surface (arrow).
case_images: JOCR-10-29-g001.jpg
case_images: PMC7476701_01_JOCR-10-29-g001.jpg
case_images: F1
case_images: On magnetic resonance imaging (MRI), a hypointense, punctate lesion surrounded by a small hyperintense zone (edema) was noted at medial aspect of patella, close to its articular surface (Fig. 1).
case_images: (a and b) Computed tomography scan of the patient (a) coronal reformat, (b) sagittal reformat, and (c) axial cut showing central nidus surrounded by minimal sclerosis.
case_images: JOCR-10-29-g002.jpg
case_images: PMC7476701_01_JOCR-10-29-g002.jpg
case_images: F2
case_images: A CT scan was done next, which showed the lesion with a central nidus, surrounded by a sclerotic rim, confirming the diagnosis of osteoid osteoma (Fig. 2).
case_images: (a and b) Percutaneous computed tomography-guided radiofrequency ablation (a) insertion of guide wire through the dorsal approach, (b) the guide wire is in position and would be replaced by the radiofrequency probe.
case_images: JOCR-10-29-g003.jpg
case_images: PMC7476701_01_JOCR-10-29-g003.jpg
case_images: F3
case_images: Once the K-wire was in place, it was replaced with a radiofrequency ablation probe, 0.7 cm in diameter and 14.4 cm long (Cool-tipTM, Medtronic) (Fig. 3).
case_images: (a-c) At 1-year follow-up, the patient has no quadriceps wasting, no extensor lag, and full flexion of the knee.
case_images: JOCR-10-29-g004.jpg
case_images: PMC7476701_01_JOCR-10-29-g004.jpg
case_images: F4
case_images: The quadriceps wasting had improved significantly and he had full range of motion (Fig. 4).