日本整形外科学会, 日本脊椎脊髄病学会監、日本整形外科学会診療ガイドライン委員会, 脊柱靱帯骨化症診療ガイドライン策定委員会編：脊柱靱帯骨化症診療ガイドライン2019．南江堂、2019.
岩﨑幹季：脊椎脊髄病学 第3版．金原出版，2022.
Shunji Matsunaga, Makoto Kukita, Kyoji Hayashi, Reiko Shinkura, Chihaya Koriyama, Takashi Sakou, Setsuro Komiya
Pathogenesis of myelopathy in patients with ossification of the posterior longitudinal ligament.
J Neurosurg. 2002 Mar;96(2 Suppl):168-72.
Abstract/Text
OBJECT: The goal of this study was to clarify the pathogenesis of myelopathy in patients with ossification of the posterior longitudinal ligament (OPLL) based on the relationship between static compression factors and dynamic factors.
METHODS: There was a total of 247 patients, including 167 patients who were conservatively followed for a mean of 11 years and 2 months and 80 patients who had myelopathy at initial consultation and underwent surgery. The changes in clinical symptoms associated with OPLL in the cervical spine were examined periodically. During the natural course of OPLL in the cervical spine, 37 (22%) of 167 patients developed or suffered aggravated spinal symptoms. All of the patients with a space available for the spinal cord (SAC) less than 6 mm suffered myelopathy, whereas the patients with an SAC diameter of 14 mm or greater did not. No correlation was found between the presence or absence of myelopathy in patients whose SAC diameter ranged from 6 mm to less than 14 mm. In patients with myelopathy whose minimal SAC diameter ranged from 6 mm to less than 14 mm, the range of motion of the cervical spine was significantly greater.
CONCLUSIONS: These results indicate that pathological compression by the ossified ligament above a certain critical point may be the most significant factor in inducing myelopathy, whereas below that point dynamic factors may be largely involved in inducing myelopathy.
Shunji Matsunaga, Takashi Sakou, Kyoji Hayashi, Yasuhiro Ishidou, Masataka Hirotsu, Setsuro Komiya
Trauma-induced myelopathy in patients with ossification of the posterior longitudinal ligament.
J Neurosurg. 2002 Sep;97(2 Suppl):172-5.
Abstract/Text
OBJECT: In these prospective and retrospective studies the authors evaluated trauma-induced myelopathy in patients with ossification of the posterior longitudinal ligament (OPLL) to determine the effectiveness of preventive surgery for this disease.
METHODS: The authors studied 552 patients with cervical OPLL, including 184 with myelopathy at the time of initial consultation and 368 patients without myelopathy at that time. In the former group of 184 patients retrospective analysis was performed using an interview survey to ascertain the relationship between onset of myelopathy and trauma. In the latter group of 368 patients prospective examination was conducted by assessing radiographic findings and noting changes in clinical symptoms apparent during regular physical examination. The follow-up period ranged from 10 to 32 years (mean 19.6 years). In the retrospective investigation, 24 patients (13%) identified cervical trauma as the trigger of their myelopathy. In the prospective investigation, 70% of patients did not develop myelopathy over a follow-up period greater than 20 years (determined using the Kaplan-Meier method). Of the 368 patients without myelopathy at the time of initial consultation, only six patients (2%) subsequently developed trauma-induced myelopathy. Types of ossification in patients who developed trauma-induced myelopathy were primarily a mixed type. All patients in whom stenosis affected 60% or greater of the spinal canal developed myelopathy regardless of a history of trauma.
CONCLUSIONS: Preventive surgery prior to onset of myelopathy is unnecessary in most patients with OPLL.
Shunji Matsunaga, Takashi Sakou, Eiji Taketomi, Setsuro Komiya
Clinical course of patients with ossification of the posterior longitudinal ligament: a minimum 10-year cohort study.
J Neurosurg. 2004 Mar;100(3 Suppl Spine):245-8.
Abstract/Text
OBJECT: Ossification of the posterior longitudinal ligament (OPLL) may produce quadriplegia. The course of future neurological deterioration in patients with radiographic evidence of OPLL, however, is not known. The authors conducted a long-term follow-up cohort study of more than 10 years to clarify the clinical course of this disease progression.
METHODS: A total of 450 patients, including 304 managed conservatively and 146 treated by surgery, were enrolled in the study. All patients underwent neurological and radiographical follow-up examinations for a mean of 17.6 years. Myelopathy was graded using Nurick classification and the Japanese Orthopaedic Association scale. Fifty-five (17%) of 323 patients without myelopathy evident at the first examination developed myelopathy during the follow-up period. Risk factors associated with the evolution of myelopathy included greater than 60% OPLL-induced stenotic compromise of the cervical canal, and increased range of motion of the cervical spine. Using Kaplan-Meier analysis, the myelopathy-free rate in patients without first-visit myelopathy was 71% after 30 years. A significant difference in final functional outcome was not observed between nonsurgical and surgical cases in which preoperative Nurick grades were 1 or 2. In patients with Nurick Grade 3 or 4 myelopathy, however, only 12% who underwent surgery eventually became wheelchair bound or bedridden compared with 89% of those managed conservatively. Surgery proved ineffective in the management of patients with Grade 5 disease.
CONCLUSIONS: Results of this long-term cohort study elucidated the clinical course of OPLL following conservative or surgical management. Surgery proved effective for the management of patients with Nurick Grades 3 and 4 myelopathy.
Motoki Iwasaki, Yoshiharu Kawaguchi, Tomoatsu Kimura, Kazuo Yonenobu
Long-term results of expansive laminoplasty for ossification of the posterior longitudinal ligament of the cervical spine: more than 10 years follow up.
J Neurosurg. 2002 Mar;96(2 Suppl):180-9.
Abstract/Text
OBJECT: The authors report the long-term (more than 10-year) results of cervical laminoplasty for ossification of the posterior longitudinal ligament (OPLL) of the cervical spine as well as the factors affecting long-term postoperative course.
METHODS: The authors reviewed data obtained in 92 patients who underwent cervical laminoplasty between 1982 and 1990. Three patients were lost to follow up, 25 patients died within 10 years of surgery, and 64 patients were followed for more than 10 years. Results were assessed using the Japanese Orthopaedic Association (JOA) scoring system for cervical myelopathy. The recovery rate was calculated using the Hirabayashi method. The mean neurological recovery rate during the first 10 years after surgery was 64%, which declined to 60% at the last follow-up examination (mean follow up 12.2 years). Late neurological deterioration occurred in eight patients (14%) from 5 to 15 years after surgery. The most frequent causes of late deterioration were degenerative lumbar disease (three patients), thoracic myelopathy secondary to ossification of the ligamentum flavum (two patients), or postoperative progression of OPLL at the operated level (two patients). Postoperative progression of the ossified lesion was noted in 70% of the patients, but only two patients (3%) were found to have related neurological deterioration. Additional cervical surgery was required in one patient (2%) because of neurological deterioration secondary to progression of the ossified ligament. The authors performed a multivariate stepwise analysis, and found that factors related to better clinical results were younger age at operation and less severe preexisting myelopathy. Younger age at operation, as well as mixed and continuous types of OPLL, was highly predictive of progression of OPLL. Postoperative progression of kyphotic deformity was observed in 8% of the patients, although it did not cause neurological deterioration.
CONCLUSIONS: When the incidence of surgery-related complications and the strong possibility of postoperative growth of OPLL are taken into consideration, the authors recommend expansive and extensive laminoplasty for OPLL.
Motoki Iwasaki, Shin'ya Okuda, Akira Miyauchi, Hironobu Sakaura, Yoshihiro Mukai, Kazuo Yonenobu, Hideki Yoshikawa
Surgical strategy for cervical myelopathy due to ossification of the posterior longitudinal ligament: Part 1: Clinical results and limitations of laminoplasty.
Spine (Phila Pa 1976). 2007 Mar 15;32(6):647-53. doi: 10.1097/01.brs.0000257560.91147.86.
Abstract/Text
STUDY DESIGN: Retrospective study of 66 patients who underwent laminoplasty for treatment of cervical myelopathy due to ossification of the posterior longitudinal ligament (OPLL).
OBJECTIVES: The present study describes surgical results of laminoplasty for treatment of cervical myelopathy due to OPLL and aims to clarify 1) factors predicting outcome and 2) limitations of laminoplasty.
SUMMARY OF BACKGROUND DATA: During the period 1986 and 1996, laminoplasty was the only surgical treatment selected for cervical myelopathy at our institutions.
METHODS: We reviewed data obtained in 66 patients who underwent laminoplasty for treatment of cervical myelopathy due to OPLL. Mean duration of follow-up was 10.2 years (range, 5-20 years). Surgical outcomes were assessed using the Japanese Orthopaedic Association (JOA) scoring system for cervical myelopathy.
RESULTS: Surgical outcome was significantly poorer in patients with occupying ratio greater than 60%. Multiple regression analysis showed that the most significant predictor of poor outcome after laminoplasty was hill-shaped ossification, followed by lower preoperative JOA score, postoperative change in cervical alignment, and older age at surgery.
CONCLUSIONS: Laminoplasty is effective and safe for most patients with occupying ratio of OPLL less than 60% and plateau-shaped ossification. However, neurologic outcome of laminoplasty for cervical OPLL was poor or fair in patients with occupying ratio greater than 60% and/or hill-shaped ossification.
Motoki Iwasaki, Shin'ya Okuda, Akira Miyauchi, Hironobu Sakaura, Yoshihiro Mukai, Kazuo Yonenobu, Hideki Yoshikawa
Surgical strategy for cervical myelopathy due to ossification of the posterior longitudinal ligament: Part 2: Advantages of anterior decompression and fusion over laminoplasty.
Spine (Phila Pa 1976). 2007 Mar 15;32(6):654-60. doi: 10.1097/01.brs.0000257566.91177.cb.
Abstract/Text
STUDY DESIGN: Retrospective study of 27 patients who underwent anterior decompression and fusion (ADF) for treatment of cervical myelopathy due to ossification of the posterior longitudinal ligament (OPLL).
OBJECTIVES: To compare surgical outcome of ADF with that of laminoplasty.
SUMMARY OF BACKGROUND DATA: During the period 1986 and 1996, laminoplasty was the only surgical treatment selected for cervical myelopathy at our institutions. According to surgical results of laminoplasty performed during this period, we have performed either laminoplasty or ADF for patients with OPLL since 1996.
METHODS: We reviewed clinical data obtained in 27 patients who underwent ADF between 1996 and 2003. Mean duration of follow-up was 6.0 years (range, 2-10 years). Surgical outcomes were assessed using the Japanese Orthopedic Association (JOA) scoring system for cervical myelopathy. Surgical results of ADF were compared with those of laminoplasty, which was performed in 66 patients during the period 1986 and 1996.
RESULTS: ADF yielded a better neurologic outcome at final follow-up than laminoplasty in patients with occupying ratio > or =60%, although graft complications occurred in 15% and additional surgical intervention was required in 26%. Neither occupying ratio of OPLL, sagittal shape of ossification, nor cervical alignment was found to be related to surgical outcome of ADF.
CONCLUSIONS: Although ADF is technically demanding and has a higher incidence of surgery-related complications, it is preferable to laminoplasty for patients with occupying ratio of OPLL > or =60%.
T Matsuoka, I Yamaura, Y Kurosa, O Nakai, S Shindo, K Shinomiya
Long-term results of the anterior floating method for cervical myelopathy caused by ossification of the posterior longitudinal ligament.
Spine (Phila Pa 1976). 2001 Feb 1;26(3):241-8.
Abstract/Text
STUDY DESIGN: Results of the anterior floating method used to decompress ossification of the posterior longitudinal ligament were studied for an average postoperative interval of 13 years.
OBJECTIVE: To investigate the long-term results of the anterior floating method used to manage ossification of the posterior longitudinal ligament.
SUMMARY OF BACKGROUND DATA: The anterior floating method is a technique that differs from the extirpation method used to manage ossification of the posterior longitudinal ligament. Reports of the long-term results from anterior decompression used to manage cervical ossification of the posterior longitudinal ligament are rare.
METHODS: The anterior floating method was used to decompress cervical ossification of the posterior longitudinal ligament in 63 patients. These patients were followed for more than 10 years with neurologic evaluations using a scoring system proposed by the Japanese Orthopedic Association (JOA score).
RESULTS: The recovery rate was 66.5% at 10 years and 59.3% at 13 years, the time of the final survey. Operative outcomes most closely reflected the preoperative duration and severity of myelopathy (JOA score) and the preoperative cross-sectional area of the spinal cord. There was no correlation with the canal narrowing ratio or the thickness of ossification of the posterior longitudinal ligament. Delayed deterioration was attributed to an original inadequate decompression and progression of ossification of the posterior longitudinal ligament outside the original operative field. There was no evidence of significant recurrent ossification of the posterior longitudinal ligament within the margins of prior decompression.
CONCLUSIONS: The anterior floating method appears to yield adequate long-term outcomes when used to manage ossification of the posterior longitudinal ligament.
I Yamaura, Y Kurosa, T Matuoka, S Shindo
Anterior floating method for cervical myelopathy caused by ossification of the posterior longitudinal ligament.
Clin Orthop Relat Res. 1999 Feb;(359):27-34.
Abstract/Text
Ossification of the posterior longitudinal ligament lessens the sagittal diameter of the cervical canal and compresses the spinal cord anteriorly, and may produce severe disabling myelopathy. The anterior floating method is one of the anterior decompression and reconstructions used in the treatment of cervical myelopathy caused by ossification of the posterior longitudinal ligament. This procedure consists of subtotal resection of vertebral bodies and discs, with slight thinning and release of the ossified ligament using air instrumentation. This is followed by reconstruction of the cervical spine using autogenous strut bone graft accompanied by postoperative application of a halo vest. This method is indicated for patients who present with moderate or severe myelopathies, and especially in those where the canal narrowing ratio exceeds 60%. This radical procedure causes decompression of the spinal cord and restores its function by enlarging the neural canal with anterior migration of the ossified ligament. The procedure minimizes the extent of surgical invasions and avoids damage to the neural tissue, because it does not require the removal of the ossification of the posterior longitudinal ligament. It also stops postoperative regrowth of the ossification. The operative results with long term followup indicate a 71% average recovery rate based on the criteria established by the Japan Orthopedic Association.
Yonenobu K, Nakamura K, Toyama Y(ed)：OPLL；ossification of the posterior longitudinal ligament. 2nd ed. Tokyo：Springer, 2006.
