Neuropathic osteoarthropathy (NOAP) describes a spectrum of destructive changes in bones and joints as a result of a neurosensory deficit. 1 Neuropathic osteoarthropathy is known by various other names, including but not limited to neuro-osteoarthropathy, neuropathic arthropathy, Charcot arthropathy, Charcot joint, or neuropathic joint. A combination of sensory, motor, and autonomic dysfunction culminates in loss of joint proprioception and loss of sensation in the joint. 2 The loss of pain perception and altered biomechanics ultimately result in joint dissolution. This disorder most commonly affects the weight-bearing joints of the lower limb and, to a lesser extent, the upper extremities and the spine. The neuropathic joint is predisposed to arthrosis, alignment deformities, fractures, and infections. [1][2][3] The location and extent of changes depend on whether the neuropathy is central or peripheral and the degree of loss of sensory, motor, and autonomic function. Various neuropathic conditions have a predilection for specific joints. Consequently, with this knowledge the radiologist often is able to suggest the correct etiology for the radiographic findings.
PathophysiologyTwo main theories are proposed to explain the pathophysiology of neuropathic osteoarthropathy-neurotraumatic and neurovascular.