OPLL (2nd ed.)

Ossification of the posterior longitudinal ligament (OPLL) is a hyperostotic condition of the spine with severe neurological deficits. In 1975 the Investigation Committee for OPLL, under the auspices of the Japanese Ministry of Health and Welfare, established diagnostic criteria for the condition, and with growing awareness of OPLL among Japanese researchers and spinal surgeons, the number of patients diagnosed with the condition in Japan has increased in recent years. As knowledge of OPLL has s