Intra-articular fragments

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Intra-articular fragments are a form of intra-articular bodies that result from traumatic injuries such as fractures, dislocations and chondral injury.

Clinical presentation

Symptoms are variable and also depend on the underlying cause and extent of the injury, but usual complaints are pain, limited motion, clicking, locking, snapping, and/or swelling.

Pathology

Intra-articular fracture fragments consist of bone, cartilage and bone, or pure cartilage depending on the extent and etiology of the injury.

If intra-articular chondral or osteochondral fragments are not identified and removed, they can progress to post-traumatic osteoarthritis .

Etiology

Typical etiologies of intra-articular fracture fragments:

articular fractures especially if multifragmentary or even comminuted
dislocations and fracture-dislocations
osteochondral fractures
chondral fractures

Radiographic Features

Osseous fragments are usually radiodense structures with sharp edges located within the joint space.

Plain radiograph

They are under many occasions difficult to detect on plain radiography due to the superposition of other bony structures .

CT

Osseous or osteochondral fragments are easily detected on CT scans, which should be performed before and after surgery in case of fracture-dislocations or complex and/or comminuted articular fractures . Pure chondral fragments, however, are not easily detectable on conventional CT.

MRI

Osseous or osteochondral fragments show thin sclerotic edges and may have parts of trabecular bone. Pure chondral fragments are of intermediate signal intensity in T1 and proton density-weighted images and are hypointense in T2 and fat-saturated proton density-weighted images. They are best detected on normal non-fat saturated proton density or T2-weighted images due to the improved contrast versus synovial fluid .

Treatment and prognosis

Intra-articular fracture fragments are usually treated operatively or arthroscopically and need to be removed or adapted if they are suitable for rescue and technical fixation . Otherwise, they can cause chondral damage and eventually leading to early osteoarthritis .