Case 65: Mono-articular Knee Arthropathy

48-years old with progressive knee pain

---

Case:

48 years old had progressive knee pain.

Radiograph (Fig. 1) shows large articular margin erosions (arrows) along the peripheral margins with mild periarticular osteopenia.

Fig. 1

The T2 sagittal image (Fig. 2) shows large synovial nodules (arrows), T2 dark with an enlarged popliteal node (red arrow).

Fig. 2

The PD fat sat coronal image (FIg. 3) shows marrow edema with free margin erosions and large central erosions (arrows).

Fig. 3

The erosions (arrows) are much better appreciated on the T1 coronal image (Fig. 4).

Fig. 4

This is a mono-articular arthropathy. While tenosynovial giant cell tumor (see case below) may occur with T2 dark large intra-articular nodules, they rarely produce free edge erosions and marrow edema.

A mono-articular arthopathy should be assumed to be infective unless proven otherwise and this pattern is commonly seen with tuberculosis.

A biopsy confirmed the diagnosis.

This case also shows Phemister’s triad.

---

Other Tuberculosis Cases

---

Index and Table of Contents

---

Previous Post

---

Content So Far

• 65 Cases

• 16 Cases of the Day

• 5 Lectures