Comparison of laminoplasty and posterior fusion surgery for cervical ossification of posterior longitudinal ligament
Authors: Nakashima Hiroaki , Imagama Shiro , Yoshii Toshitaka , Egawa Satoru , Sakai Kenichiro , Kusano Kazuo , Nakagawa Yukihiro , Hirai Takashi , Wada Kanichiro , Katsumi Keiichi , Fujii Kengo , Kimura Atsushi , Furuya Takeo , Kanchiku Tsukasa , Nagamoto Yukitaka , Oshima Yasushi , Nagoshi Narihito , Ando Kei , Takahata Masahiko , Mori Kanji , Nakajima Hideaki , Murata Kazuma , Matsunaga Shunji , Kaito Takashi , Yamada Kei , Kobayashi Sho , Kato Satoshi , Ohba Tetsuro , Inami Satoshi , Fujibayashi Shunsuke , Katoh Hiroyuki , Kanno Haruo , Li Yuanying , Yatsuya Hiroshi , Koda Masao , Kawaguchi Yoshiharu , Takeshita Katsushi , Matsumoto Morio , Yamazaki Masashi , Okawa Atsushi ,   Japanese Multicenter Research Organization for Ossification of the Spinal Ligament, Nakashima Hiroaki , Imagama Shiro , Yoshii Toshitaka , Egawa Satoru , Sakai Kenichiro , Kusano Kazuo , Nakagawa Yukihiro , Hirai Takashi , Wada Kanichiro , Katsumi Keiichi , Fujii Kengo , Kimura Atsushi , Furuya Takeo , Kanchiku Tsukasa , Nagamoto Yukitaka , Oshima Yasushi , Nagoshi Narihito , Ando Kei , Takahata Masahiko , Mori Kanji , Nakajima Hideaki , Murata Kazuma , Matsunaga Shunji , Kaito Takashi , Yamada Kei , Kobayashi Sho , Kato Satoshi , Ohba Tetsuro , Inamia Satoshi , Fujibayashi Shunsuke , Katoh Hiroyuki , Kanno Haruo , Koda Masao , Kawaguchi Yoshiharu , Takeshita Katsushi , Matsumoto Morio , Yamazaki Masashi , Okawa Atsushi 
Published: January 2022

This prospective multicenter study, established by the Japanese Ministry of Health, Labour and Welfare and involving 27 institutions, aimed to compare postoperative outcomes between laminoplasty (LM) and posterior fusion (PF) for cervical ossification of the posterior longitudinal ligament (OPLL), in order to address the controversy surrounding the role of instrumented fusion in cases of posterior surgical decompression for OPLL. 478 patients were considered for participation in the study; from among them, 189 (137 and 52 patients with LM and PF, respectively) were included and evaluated using the Japanese Orthopaedic Association (JOA) scores, the JOA Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), and radiographical measurements. Basic demographic and radiographical data were reviewed, and the propensity to choose a surgical procedure was calculated. Preoperatively, there were no significant differences among the participants in terms of patient backgrounds, radiographical measurements (K-line or cervical alignment on X-ray, OPLL occupation ratio on computed tomography, increased signal intensity change on magnetic resonance imaging), or clinical status (JOA score and JOACMEQ) after adjustments. The overall risk of perioperative complications was found to be lower with LM (odds ratio [OR] 0.40, p = 0.006), and the rate of C5 palsy occurrence was significantly lower with LM (OR 0.11, p = 0.0002) than with PF. The range of motion (20.91° ± 1.05° and 9.38° ± 1.24°, p < 0.0001) in patients who had PF was significantly smaller than in those who had LM. However, multivariable logistic regression analysis showed no significant difference among the participants in JOA score, JOA recovery rate, or JOACMEQ improvement at two years. In contrast, OPLL progression was greater in the LM group than in the PF group (OR 2.73, p = 0.0002). Both LM and PF for cervical myelopathy due to OPLL had resulted in comparable postoperative outcomes at 2 years after surgery.