Case Study: 14-year-old with Tuberculosis of the Patella

Although osteoarticular tuberculosis (TB), or TB of the bones, is no longer common in Western countries, migrant populations and people who are immunocompromised have brought about a resurgence of the disease.

Osteoarticular TB can occur in the knee - one study found of 1074 cases, 8.3 percent - or 90 cases - affected the knee. However, among those affecting the knee, only 1 involved the patella, or kneecap. Therefore, it is a rare occurrence.

In this case, a 14-year-old boy presented to the doctor with a 2-month history of pain and swelling of his left knee. After testing for TB, the doctor found by x-ray a lesion of bone deterioration on the patella. Because of the TB test results, the doctor diagnosed osteoarticular TB. The lesion on the knee was biopsied (tested) and no cancer was found. The area was surgically cleaned and the patient was given a course of anti-TB medications.

The authors of this case note that early diagnosis of osteoarticular TB, although rare, is important in order to prevent the disease from spreading beyond the initial area. Although the knee is considered to be the third most common site for TB, the patella is not.

In conclusion, the authors suggest treatment should include biopsy to rule out cancer, cleaning and debriding of the lesion, and a prompt start to medication for treatment.