Dislocation

What it means

A joint is the place where two bones meet, held in position by ligaments, a capsule, and surrounding muscle. A dislocation is when those bones move out of their normal alignment. A complete dislocation means the surfaces no longer touch at all; a subluxation means the bones are partly out of place but still in contact. Some joints (shoulder, finger, kneecap) dislocate relatively easily; others (hip, large joints of the spine) take significant force and almost always come with other injuries.

Why it appears on a CT or MRI report

Reports name the joint, the direction of displacement (anterior, posterior, inferior), and whether it is a full dislocation or a subluxation. The radiologist looks for associated injuries: fractures of nearby bone, torn ligaments, damaged cartilage (labrum, meniscus), trapped soft tissue, and nerve or vessel involvement. On the spine, dislocation is described in terms of vertebral alignment and any narrowing of the spinal canal. CT shows bones best; MRI shows the soft-tissue damage around the joint.

What it usually means

Most acute dislocations need reduction — the bones put back into place — as soon as it is safe to do so, often in an emergency department. The longer a joint stays out, the higher the risk of damage to cartilage, blood vessels, or nerves. Some joints, like the shoulder, dislocate repeatedly once it has happened the first time, and management may shift toward physical therapy or surgical stabilization. Subluxation is generally less urgent: it may resolve on its own with rest, bracing, and rehabilitation, especially when it reflects underlying joint laxity rather than a single injury. Hip dislocations, knee dislocations involving the femur and tibia, and spine dislocations are treated as emergencies because of the risk to nearby blood vessels and the spinal cord. Old or chronic dislocations that have been present for a long time are sometimes left alone if the joint has stabilised and surgery would do more harm than good.

When to follow up

If this is on an emergency scan, the team will already be planning reduction. For outpatient findings, talk to your doctor or orthopaedic specialist promptly to plan treatment. Seek urgent care for a joint that looks visibly out of place, severe pain that does not settle, numbness or pins-and-needles below the joint, a cold or pale limb, inability to move the joint, or rapidly worsening swelling. After reduction, follow rehabilitation advice carefully to reduce the chance of it happening again.

A plain-language way to picture it

Think of a door hinge. Normally the pin sits cleanly inside the loops and the door swings smoothly. A full dislocation is the pin slipping all the way out — the door hangs uselessly until someone reseats it. A subluxation is the pin half out, still catching on the loop but not lined up correctly. Either way, the door doesn't move the way it should until the hinge is back where it belongs.