Q1: What are the features seen on the radiographs (see 301)?

The radiographs of the left elbow show multiple radio-opaque loose bodies of variable size.

Q2: What is the likely diagnosis?

The diagnosis is synovial chondromatosis of left elbow.

Q3: What is the line of management?

If the patient is symptomatic, removal of loose bodies and synovectomy by arthroscopy or arthrotomy is advocated.

Discussion

Synovial chondromatosis is a synovial proliferative disease in which cartilaginous or osteocartilaginous metaplasia occurs within the synovial membrane. It most commonly involves knee and hip joints, but any joint, bursa, or tendon sheath may be affected.¹ Involvement of the elbow joint is very rare.

Patients are observed in their second to seventh decades of life, and usually report gradual onset of pain, stiffness, or an enlarging mass around the affected joint. Limitation of motion is a characteristic finding on clinical examination.

There are three phases of the disease²:

1. Early with synovial chondrometaplasia but no loose bodies.

2. Transitional with active synovial disease and loose bodies.

3. Late with loose bodies but no synovial disease.

Routine roentgenograms may show multiple loose bodies, but especially in the hip, routine films are often normal. Other studies such as arthrography, magnetic resonance imaging, or arthroscopy may be needed.

At surgery multiple loose bodies, both free and attached to the synovium, are visible. Microscopically discrete nodules of disorganised cartilaginous tissue in the synovium, characterised by cellular crowding with cytologic atypia is remarkable. This disordered appearance of primary synovial chondromatosis differentiates it from the more common secondary chondromatosis, which occurs in association with osteoarthritis, traumatic loose bodies, and osteochondritis dissecans. Calcification and endochondral ossification of cartilage nodules may occur.

Treatment is controversial: many advise synovectomy and removal of loose bodies,^{3, 4} others prefer simple removal of loose bodies either by arthroscopy or open operation. Recurrence frequently occurs after surgery and this can progress to osteoarthritis. There are rare reports of malignant transformation to chondrosarcoma.

Final diagnosis

Synovial chondromatosis of the left elbow joint.