In order to discuss the surgical approaches used in surgery fbr ossification of the cervical longitudinal ligament ( OPLL ) , we undertook retr 〔 〕spective study of 240 cases with OPLL operated on in the past l 7 years . The patients were grQuped imo 3categories dcpending upon the approaches adopted in the operation , Those were anterior decompression group ( A ) , posterior decompression group ( P ) and combined group( C ) , In group A , anterior fusion was carried out , after removal of OPLL

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... ia 血 e anterior approach . In group P , laminectomy or laminoplasy was pe ormed , In group C , both anterior and posterior decompression were pe formed in a two stage operation . There were l 81men and 59 women with a mean age of 56. 3 years old , Group P had a significantly higher mean age than group A and C . Preoperative neuro } ogy indicated 〔 hat myelopa 血 y had became more severe in group P than in group A and more severe in group C than in group P. Preoperative neuroradiologica 且studies indicated thauhe OPLL extended longer rostro − caudally in group C than in group A and longer in group P than in group C . CT − myelography ( CTM )showed the thickest part of the OPLL in group A − Fas less than SO% of the A − P dis 旺mce of the spinal canal , while the stenotic ratio was over 50% in group P and C . Extent of anterior fusion was with 血 2intervertebral spaces in 78 , 3 % of group A and 60 % of group C 、 Anterior f廿sion of more than 3 intervertebral space was carried out in 40% of group C . Cervical canal stenosis was complicated in 8, 7, 24. 6 and 34% in group A , P and C , respectively . Thus it was evident tha [ patients in group A had smaller OPLL 乱nd were neurologically less affected compared to group P and C . The operation proved effective in more than 89% of the patients in this group . Neurologically , patients in group C had the severest myelopathy and had larger OPLL than patients of group A . The rostro −caudal extent of OPLL was the largest in group P though myelopathy was less severe than that in group C . lncidence of sequel was 7, 6 , 4 . O and l 8% in group A , P and C , respectively . In group C , all the sequelac were provoked in the anterior approach . Altemative techniques to improve the results among group C patients were discussed , The results suggested that posterior decornpression was the safest approach in the surgical management of OPLL . Key Words ; OPLL , surgical treatment , anteric } r decompression, posterior decompression , osteoplastic laminotomy .