Natural Course of OPLL in the Cervical Spine

One hundred and twelve patients of OPLL in the cervical spine who had been treated conservatively were followed up clinically and radiologically. The progression of the ossification was seen in 46 of 63 cases followed up more than 5 years (73%) and in 28 of 49 cases less than 5 years (57%).In those who showed the progression of ossification, worsening or development of mye-lopathy were found likely to happen at the higher rate.