Spine Surgery and Related Research (Apr 2019)

Risk Factors for Proximal Junctional Fracture Following Fusion Surgery for Osteoporotic Vertebral Collapse with Delayed Neurological Deficits: A Retrospective Cohort Study of 403 Patients

  • Koji Tamai,
  • Hidetomi Terai,
  • Akinobu Suzuki,
  • Hiroaki Nakamura,
  • Kei Watanabe,
  • Keiichi Katsumi,
  • Masayuki Ohashi,
  • Yohei Shibuya,
  • Tomohiro Izumi,
  • Toru Hirano,
  • Takashi Kaito,
  • Tomoya Yamashita,
  • Hiroyasu Fujiwara,
  • Yukitaka Nagamoto,
  • Yuji Matsuoka,
  • Hidekazu Suzuki,
  • Hirosuke Nishimura,
  • Atsushi Tagami,
  • Syuta Yamada,
  • Shinji Adachi,
  • Toshitaka Yoshii,
  • Shuta Ushio,
  • Katsumi Harimaya,
  • Kenichi Kawaguchi,
  • Nobuhiko Yokoyama,
  • Hidekazu Oishi,
  • Toshiro Doi,
  • Atsushi Kimura,
  • Hirokazu Inoue,
  • Gen Inoue,
  • Masayuki Miyagi,
  • Wataru Saito,
  • Atsushi Nakano,
  • Daisuke Sakai,
  • Tadashi Nukaga,
  • Shota Ikegami,
  • Masayuki Shimizu,
  • Toshimasa Futatsugi,
  • Seiji Ohtori,
  • Takeo Furuya,
  • Sumihisa Orita,
  • Shiro Imagama,
  • Kei Ando,
  • Kazuyoshi Kobayashi,
  • Katsuhito Kiyasu,
  • Hideki Murakami,
  • Katsuhito Yoshioka,
  • Shoji Seki,
  • Michio Hongo,
  • Kenichiro Kakutani,
  • Takashi Yurube,
  • Yasuchika Aoki,
  • Masashi Oshima,
  • Masahiko Takahata,
  • Akira Iwata,
  • Hirooki Endo,
  • Tetsuya Abe,
  • Toshinori Tsukanishi,
  • Kazuyoshi Nakanishi,
  • Kota Watanabe,
  • Tomohiro Hikata,
  • Satoshi Suzuki,
  • Norihiro Isogai,
  • Eijiro Okada,
  • Haruki Funao,
  • Seiji Ueda,
  • Yuta Shiono,
  • Kenya Nojiri,
  • Naobumi Hosogane,
  • Ken Ishii

DOI
https://doi.org/10.22603/ssrr.2018-0068
Journal volume & issue
Vol. 3, no. 2
pp. 171 – 177

Abstract

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Introduction: Approximately 3% of osteoporotic vertebral fractures develop osteoporotic vertebral collapse (OVC) with neurological deficits, and such patients are recommended to be treated surgically. However, a proximal junctional fracture (PJFr) following surgery for OVC can be a serious concern. Therefore, the aim of this study is to identify the incidence and risk factors of PJFr following fusion surgery for OVC. Methods: This study retrospectively analyzed registry data collected from facilities belonging to the Japan Association of Spine Surgeons with Ambition (JASA) in 2016. We retrospectively analyzed 403 patients who suffered neurological deficits due to OVC below T10 and underwent corrective surgery; only those followed up for 2 years were included. Potential risk factors related to the PJFr and their cut-off values were calculated using multivariate logistic regression analysis and receiver operating characteristic (ROC) analysis. Results: Sixty-three patients (15.6%) suffered PJFr during the follow-up (mean 45.7 months). In multivariate analysis, the grade of osteoporosis (grade 2, 3: adjusted odds ratio (aOR) 2.92; p=0.001) and lower instrumented vertebra (LIV) level (sacrum: aOR 6.75; p=0.003) were independent factors. ROC analysis demonstrated that lumbar bone mineral density (BMD) was a predictive factor (area under curve: 0.72, p=0.035) with optimal cut-off value of 0.61 g/cm2 (sensitivity, 76.5%; specificity, 58.3%), but that of the hip was not (p=0.228). Conclusions: PJFr was found in 16% cases within 4 years after surgery; independent risk factors were severe osteoporosis and extended fusion to the sacrum. The lumbar BMD with cut-off value 0.61 g/cm2 may potentially predict PJFr. Our findings can help surgeons select perioperative adjuvant therapy, as well as a surgical strategy to prevent PJFr following surgery.

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