What is chronic compression deformity of the t12?

Answer 1

Break down phrases word by word to grasp the meaning. In the phrase, " chronic compression deformity", chronic means long-term. It's usually an injury or condition that is at minimum over 6 months old (to years old). A chronic condition can start at any age. Compression isn't specified here but generally has to do with bone, often spinal vertebra. But it doesn't say 'old compression fracture', which is a common cause of compression of vertebra. Osteoporosis is also a common cause leading to collapse or compressing of one bony structure onto another bony structure. A deformity in medical parlance is any abnormal positioning of a body part. So for example, if your fingers permanently curled into a claw-like position, often caused by severe Arthritis or nerve injury, doctors might refer to that as a "deformity". However, medical people try to get away from older terms like deformity, because it sounds so negatively biased against the person.

So though your question doesn't specify what is "compressed", my best guess would be a long-ago (chronic) injury or circumstance that caused a collapse of a bony structure, most likely of one or more spinal vertebra, that when it healed left the person hunched over, or a body part twisted or in some other abnormal position.

Compression injuries often affect nerves in the area, since nerves pass through or over bony structures. So the deformity could be from long term pressure (compression) on a spinal or peripheral nerve.