This is a case of tuberculous arthritis with osteomyelitis, soft tissue abscesses and cellulitis of the right hip joint.

Musculoskeletal tuberculosis is a less common manifestation of tuberculosis, accounting for only 1-2% of all tuberculous cases ¹.

Tuberculous arthritis is a form of monoarthritis that affects the large weight-bearing joints such as the hip joints ¹, as in our case. This disease is usually diagnosed when there is peri-articular osteoporosis, peripherally located bony erosions and gradual diminution of the joint space (parameters that comprise the Phemister’s triad) ^1-3.

MRI shows proliferation of the synovium, which is typically T2W hypointense and shows vivid enhancement after administration of gadolinium. MRI is also useful in the demonstration of marrow and soft tissue changes, joint effusion, cartilage and bone erosions. Thus, MRI can show associated abnormalities such as osteomyelitis, myositis, cellulitis, paraarticular abscesses, tenosynovitis, bursitis, skin ulceration or sinus tract formation. 

For our particular case, osteopenia, bony erosions and flattening of the femoral head with subsequent narrowing of the right hip joint space are demonstrated. MRI revealed hyperintense bone marrow signals involving the right femur and acetabulum. Similar hyperintense signals with evidence of peripheral enhancement are noted in the hip joint space, surrounding muscles (specifically the right gluteus minimus and medius, proximal right vastus lateralis, tensor fascia lata and rectus femoris as well as the distal iliopsoas and pectineus muscles) and subcutaneous soft tissues which are consistent with abscess formations. T2W hyperintense and T1W hypointense reticular or lace-like patterns are seen in the surrounding subcutaneous fat with overlying skin thickening indicative of cellulitis.