Shiro Imagama1,2, Kei Ando1,2, Kazuhiro Takeuchi3,2, Satoshi Kato4,2, Hideki Murakami4,2, Toshimi Aizawa5,2, Hiroshi Ozawa6,2, Tomohiko Hasegawa7,2, Yukihiro Matsuyama7,2, Masao Koda8,2, Masashi Yamazaki8,2, Hirotaka Chikuda9,2, Shigeo Shindo10,2, Yukihiro Nakagawa11,2, Atsushi Kimura12,2, Katsushi Takeshita12,2, Kanichiro Wada13,2, Hiroyuki Katoh14,2, Masahiko Watanabe14,2, Kei Yamada15,2, Takeo Furuya16,2, Takashi Tsuji17,2, Shunsuke Fujibayashi18,2, Kanji Mori19,2, Yoshiharu Kawaguchi20,2, Kota Watanabe21,2, Morio Matsumoto21,2, Toshitaka Yoshii22,2, Atsushi Okawa22,2. 1. Department of Orthopedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan. 2. Japanese Organization of the Study for Ossification of Spinal Ligament (JOSL), Japan. 3. Department of Orthopedic Surgery, National Hospital Organization Okayama Medical Center, Okayama, Japan. 4. Department of Orthopedic Surgery, Kanazawa University, Kanazawa, Japan. 5. Department of Orthopedic Surgery, Tohoku University School of Medicine, Sendai, Japan. 6. Department of Orthopedic Surgery, Tohoku Medical and Pharmaceutical University, Sendai, Japan. 7. Department of Orthopedic Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan. 8. Department of Orthopedic Surgery, University of Tsukuba, Tsukuba, Japan. 9. Department of Orthopedic Surgery, Gunma University Graduate School of Medicine, Maebashi, Japan. 10. Department of Orthopedic Surgery, Kudanzaka Hospital, Tokyo, Japan. 11. Department of Orthopedic Surgery, Wakayama Medical University, Wakayama, Japan. 12. Department of Orthopedics, Jichi Medical University, Tochigi, Japan. 13. Department of Orthopedic Surgery, Hirosaki University Graduate School of Medicine, Hirosaki, Japan. 14. Department of Orthopedic Surgery, Surgical Science, Tokai University School of Medicine, Kanagawa, Japan. 15. Department of Orthopedic Surgery, Kurume University School of Medicine, Kurume, Japan. 16. Department of Orthopedic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan. 17. Department of Orthopedic Surgery, Fujita Health University, Toyoake, Japan. 18. Department of Orthopedic Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan. 19. Department of Orthopedic Surgery, Shiga University of Medical Science, Shiga, Japan. 20. Department of Orthopedic Surgery, Faculty of Medicine, University of Toyama, Toyama, Japan. 21. Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo, Japan. 22. Department of Orthopedic Surgery, Tokyo Medical and Dental University, Tokyo, Japan.
Abstract
STUDY DESIGN: Prospective, multicenter, nationwide study. OBJECTIVE: To investigate perioperative complications and risk factors in surgery for thoracic ossification of the posterior longitudinal ligament (T-OPLL) using data from the registry of the Japanese Multicenter Research Organization for Ossification of the Spinal Ligament. SUMMARY OF BACKGROUND DATA: There is no prospective multicenter study of surgical complications and risk factors for T-OPLL, and previous multicenter retrospective studies have lacked details. METHODS: Surgical methods, preoperative radiographic findings, pre- and postoperative thoracic myelopathy (Japanese Orthopaedic Association [JOA] score), prone and supine position test (PST), intraoperative ultrasonography, and intraoperative neurophysiological monitoring (IONM) were investigated prospectively in 115 cases (males: 55, females: 60, average age 53.1 y). Factors related to perioperative complications and risk factors for postoperative motor palsy were identified. RESULTS: Posterior decompression and fusion with instrumentation with or without dekyphosis was performed in 85 cases (74%). The JOA recovery rate at 1 year after surgery in all cases was 55%. Motor palsy occurred postoperatively in 37 cases (32.2%), with a mean recovery period of 2.7 months. A long recovery period for postoperative motor palsy was significantly associated with a high number of T-OPLL levels (P < 0.0001), lower preoperative JOA score (P < 0.05), and greater estimated blood loss (P < 0.05). Perioperative complications or postoperative motor palsy were significantly related to a higher number of T-OPLL levels, comorbid ossification of ligamentum flavum rate, lower preoperative JOA score, higher preoperative positive PST rate, more surgical invasiveness, a lower rate of intraoperative spinal cord floating in ultrasonography, and higher rate of deterioration of IONM. CONCLUSION: This study firstly demonstrated the perioperative complications with high postoperative motor palsy rate in a nationwide multicenter prospective study. Surgical outcomes for T-OPLL should be improved by identifying and preventing perioperative complications with significant risk factors. LEVEL OF EVIDENCE: 3.
STUDY DESIGN: Prospective, multicenter, nationwide study. OBJECTIVE: To investigate perioperative complications and risk factors in surgery for thoracic ossification of the posterior longitudinal ligament (T-OPLL) using data from the registry of the Japanese Multicenter Research Organization for Ossification of the Spinal Ligament. SUMMARY OF BACKGROUND DATA: There is no prospective multicenter study of surgical complications and risk factors for T-OPLL, and previous multicenter retrospective studies have lacked details. METHODS: Surgical methods, preoperative radiographic findings, pre- and postoperative thoracic myelopathy (Japanese Orthopaedic Association [JOA] score), prone and supine position test (PST), intraoperative ultrasonography, and intraoperative neurophysiological monitoring (IONM) were investigated prospectively in 115 cases (males: 55, females: 60, average age 53.1 y). Factors related to perioperative complications and risk factors for postoperative motor palsy were identified. RESULTS: Posterior decompression and fusion with instrumentation with or without dekyphosis was performed in 85 cases (74%). The JOA recovery rate at 1 year after surgery in all cases was 55%. Motor palsy occurred postoperatively in 37 cases (32.2%), with a mean recovery period of 2.7 months. A long recovery period for postoperative motor palsy was significantly associated with a high number of T-OPLL levels (P < 0.0001), lower preoperative JOA score (P < 0.05), and greater estimated blood loss (P < 0.05). Perioperative complications or postoperative motor palsy were significantly related to a higher number of T-OPLL levels, comorbid ossification of ligamentum flavum rate, lower preoperative JOA score, higher preoperative positive PST rate, more surgical invasiveness, a lower rate of intraoperative spinal cord floating in ultrasonography, and higher rate of deterioration of IONM. CONCLUSION: This study firstly demonstrated the perioperative complications with high postoperative motor palsy rate in a nationwide multicenter prospective study. Surgical outcomes for T-OPLL should be improved by identifying and preventing perioperative complications with significant risk factors. LEVEL OF EVIDENCE: 3.