1. A patient wholly insensitive to painful stimuli as judged by psychical, physical, reflex and autonomic responses, showed multiple arthropathies.

2. Biopsy specimens of skin and periosteum from the region of the hip joint showed free nerve terminals similar in morphology to endings considered to subserve pain in normal subjects. The abnormality related to defective pain sensation therefore appears not to be due to a defect in the peripheral nerve endings for pain, but to be located more centrally in the nervous system.

3. In this patient, and in some patients with syringomyelia, arthropathy is associated with selective impairment of pain sensibility of the involved joints. It appears that tissue damage from the wear and tear of normal activity of a joint, if this damage is unheralded because of impairment of pain sense, can lead to arthropathy.

4. It is noted that further experimental evidence is still required to elucidate the role of various modalities of innervation in the maintenance of normal structure and function of joints.