Dislocations (prosthetic and non-prosthetic)

Understanding this condition

A dislocation is the complete loss of contact between the two surfaces of a joint. In a native joint, it most often results from a significant trauma (hip, knee, or ankle dislocation). In a prosthetic joint, it can occur during an extreme movement or a fall, and sometimes with a moderate effort when the alignment of the components is not optimal.

Dislocations are emergencies because the prolonged position can damage nearby vessels and nerves, as well as joint structures.

Symptoms

Very acute pain, visible deformity, absolute inability to mobilise the joint. The position of the limb is characteristic according to the type of dislocation.

The examination systematically looks for vascular or nerve injury (the diagnosis is clinical, supplemented by X-rays to confirm and look for associated lesions).

How can it progress?

A dislocation that is not reduced promptly can lead to permanent vascular and nerve damage, bone necrosis, and major joint sequelae. For a dislocated prosthesis, failure to reduce can damage the prosthetic components.

Treatment options

Urgent reduction, most often under general anaesthesia (or sedation). X-ray check following reduction, then immobilisation to allow healing of the damaged structures.

In cases of repeated prosthetic dislocations, surgical revision may be necessary (component exchange, repositioning). A specialist consultation is essential. For any acute dislocation, attending an emergency department is imperative.