Ans. is 'a' i.e., Neuropathy o Another name given to joint affected by neuropathic arthropathy is charcot's joint.Neuropathic joint (CharcqaCslomt)o It is a progressive destructive arthritis associated with loss of pain sensation, proprioception or both, in addition normal muscular reflexes that modulate joint movements are decreased,o Without these protective mechanisms, joints are subjected to repeated trauma, resulting in progressive cartilage and bone damage.a It is most commonly caused by diabetes meliitus.Pathophysiologyo At least two underlying mechanisms are believed to be involved in the pathogenesis of neuropathic arthritis.An abnormal autonomic nervous system is thought to be responsible for the increased blood flow to the joint and subsequent resorption of bone.With the loss of deep pain, proprioception and protective neuromuscular reflexes, the joint is subjected to repeated injuries including ligamental tears and bone fractures.Pathologyo The pathological changes seen in charcoal's joints are similar to those found in severe osteoarthritic joint.o There is fragmentation and eventual loss of articular cartilage with ebu motion of the underlying bone.o Osteophytes are found at the joint margins.o With more advanced diseases, erosions are present on the joint surface. Fractures, devitalized bone, and intraarticular loose bodies may be present. Joint effusions are prominent.Clinical manifestationso Usually begins in a single joint and then progresses to involve other joints.o The involved joints progressively becomes enlarged from bony overgrowth and synovial effusion.o Loose bodies may be palpated in the joint cavity.o Joint instability, subluxation and crepitus occur.o The joint pain experienced by the patient is less than that would be anticipated based on the degree of joint involvement.Causes of Neuropathic joint disease (Chareoat's joint)o Diabetes mellitus (most common)o Tabes Dorsaliso Meningomyeloceleo Syringomyeliao Amyloidosiso Leprosyo Congenital indifference to paino Peroneal muscular atrophy