We report a case of ossification of the patellar tendon in a high school baseball player. The patient is a 16-year-old boy started to play baseball when 7-years-old. He had been feeling pain in his right knee for 4 years prior to presentation.
On examination, a hard mass was palpable on the lateral aspect of the right patellar tendon. Radiographs, CT and MRI, showed bone-like shadow on the patellar tendon, but laboratory data were normal. Surgery revealed ossification of the patellar tendon. Pathological investigation revealed this to be bone tissue. The ossification may have been due to abnormal repair of patellar tendonitis.
