Joint destruction caused by damage to the nervous system which prevents the patient feeling sensations in the joint. Due to the nerve damage, pain and damage to the joint often goes unnoticed as the joint deteriorates even further. The knee and ankle are the most common joints affected. The condition is usually caused by an underlying diseases which affects the nerves e.g. diabetic neuropathy, syringomyelia, spinal cord injury and pernicious anemia. See also Arthropathy, Neurogenic