Study　Design:　Alignment　of　the　cervical　spine　(C2-C7　angle)　after　open-door　laminoplasty,　preserving　the　posterior　cervical　ligamentous　complex　and　reattachment　of　the　insertion　of　extensors,　was　investigated　retrospectively　in　patients　with　the　ossification　of　the　posterior　longitudinal　ligament　(OPLL)　with　disease　extent　reaching　the　epistropheus.　Objective:　Methods　of　posterior　decompression　and　extensor　reconstruction　in　the　treatment　of　OPLL　with　disease　extent　reaching　the　epistropheus　are　investigated　in　this　paper.　Methods:　In　10　cases　of　OPLL　with　disease　extent　reaching　C2,　in　which　posterior　cervical　ligamentous　complexes　are　retained,　the　C2　attachment　point　of　extensor　was　reconstituted　and　open-door　cervical　laminoplasty　was　performed,　with　the　decompression　range　of　laminoplasty　being　C2　to　C7.　The　average　follow-up　time　was　14　months.　Observation:　C2　effective　vertebral　canal　sagittal　diameter　before　and　after　the　surgery　was　determined　using　computed　tomography　to　observe　the　degree　of　decompression;　the　C2-C7　angle　before　and　after　the　surgery　were　measured　using　x-ray,　and　the　maintenance　of　the　physiological　curve　was　then　observed;　Japanese　Orthopaedic　Association　scoring　was　conducted　before　and　after　operation,　and　during　the　follow-up.　Results:　The　average　effective　vertebral　canal　sagittal　diameter　before　the　surgery　was　5.6　mm　(4　to　8.8　mm),　whereas　that　after　the　surgery　was　13.4　mm　(10　to　18.2　mm)　(P　＜　0.01　compared　with　that　before　the　operation);　the　C2-C7　angle　of　the　neutral　position　was　6.5　degrees　(-2　to　12　degrees),　whereas　that　after　the　surgery　was　7.4　degrees(3　to　14　degrees),　and　that　during　the　last　follow-up　was　7.0　degrees　(2　to　15　degrees)　(P　＞　0.05　compared　with　that　before　the　operation).　The　Japanese　Orthopaedic　Association　score　before　the　surgery　was　6　to　12,　with　an　average　of　9.6,　whereas　that　after　the　surgery　was　8　to　14,　with　an　average　of　10.9,　and　that　during　the　last　follow-up　was　10　to　17,　with　an　average　of　13.2　(P　＜　0.05　compared　with　that　before　the　operation).　Conclusions:　The　open-door　cervical　laminoplasty　in　which　posterior　cervical　ligamentous　complexes　are　retained　and　the　attachment　point　of　extensor　muscles　is　reconstructed　is　applicable　to　OPLL　with　disease　extent　reaching　the　epistropheus,　and　the　objective　of　complete　decompression　and　the　maintenance　of　the　physiological　curve　of　cervical　vertebra　can　be　achieved.