Neurogenic acceleration of degenerative joint lesions

A severe form of degenerative joint lesion (neuropathic arthropathy) is known to complicate a variety of diseases that are associated with sensory abnormalities. We studied the relationship between sensory deficits and the development of degenerative joint lesions in dogs in two complementary experiments. In Experiment 1, dogs that were subjected to unilateral dorsal-root ganglionectomy (fourth lumbar to first sacral vertebra) failed to show biochemical, gross, or histological evidence of degenerative joint lesions in ipsilateral femoral condylar cartilage after sixteen months. In Experiment 2, five of six dogs that were subjected to transection of the anterior cruciate ligament two weeks after deafferentation of the ipsilateral limb showed striking gross or histological lesions, or both, of the femoral condylar cartilage three weeks after ligament transection (five weeks after ganglionectomy). We concluded that the neuromuscular mechanisms that protect normal joints from damage are inadequate to protect unstable joints from becoming rapidly and severely damaged.