BPC179
Free Paper (Best Paper Session)
Prediction of Revision Surgery After Balloon Kyphoplasty Based on a Novel Computed Tomography-Based Endplate Injury Classification for Osteoporotic Vertebral Fractures
Masayoshi Iwamae, MD, PhD1, Shinji Takahashi, MD, PhD1*, Yuta Sawada, MD, PhD1, Shoichiro Ohyama, MD, PhD2, Yoshifumi Takahashi, MD3, Hiroyuki Yasuda, MD, PhD4, Takamitsu Haku, MD5, Yusuke Hori, MD, PhD6, Akito Yabu, MD, PhD6, Masatoshi Hoshino, MD, PhD5, Masaki Terakawa, MD6, Ryo Sasaki, MD1 4, Hiroshi Kono, MD, PhD3, Tadao Tsujio, MD, PhD8, Sadahiko Konishi, MD, PhD4, Minori Kato, MD, PhD1, Hiromitsu Toyoda, MD, PhD1, Akinobu Suzuki, MD, PhD1, Koji Tamai, MD, PhD1, Yuki Okamura, MD1, Yuto Kobayashi, MD1, Masato Uematsu, MD1, Hiroshi Taniwaki, MD1, Yuki Kinoshita, MD1, Masashi Tsujino, MD1, Hiroaki Nakamura, MD, PhD1, Hidetomi Terai, MD, PhD1
1Department of Orthopaedic Surgery, Osaka Metropolitan University Graduate School of Medicine, Osaka, Japan 2Department of Orthopaedic Surgery, Nishinomiya Watanabe Hospital, Hyogo, Japan 3Department of Orthopaedic Surgery, Ishikiri Seiki Hospital, Osaka, Japan 4Department of Orthopaedic Surgery, Osaka General Hospital of West Japan Railway Company, Osaka, Japan 5Department of Orthopaedic Surgery, Saiseikai Nakatsu Hospital, Osaka, Japan 6Department of Orthopaedic Surgery, Osaka City General Hospital, Osaka, Japan 7Department of Orthopaedic Surgery, Osaka Rosai Hospital, Osaka, Japan 8Department of Orthopaedic Surgery, Shiraniwa Hospital, Nara, Japan
Study Design: Case-control study. Objective: This study aimed to develop a computed tomography (CT)-based endplate injury classification and a scoring system reflecting the risk of revision surgery after balloon kyphoplasty (BKP) for fresh osteoporotic vertebral fractures (OVF). Summary of Background Data: BKP is a minimally invasive option for OVF, providing immediate pain relief. However, postoperative complications such as adjacent fractures, cement loosening, or cement dislodgement can require reoperation. Although the fracture morphology is related to reoperation, detailed classification of endplate injury has not been established. Methods: This study included 108 patients without any reoperation and 33 patients who required revision surgery after BKP. Revision surgery was defined as additional posterior fusion surgery that included the previously BKP-treated vertebra. The CT-based endplate injury classification was categorized as: (1) isolated endplate (none, unilateral, bilateral); (2) endplate injury (none, unilateral, bilateral, split type); and (3) endplate defect (none, ≥3-mm defect). Logistic regression identified independent risk factors for revision surgery, and a point-based risk score was developed using regression coefficients. The point-based risk score was validated using receiver operating characteristic (ROC) analysis. Results The CT-based endplate injury classification showed excellent reliability (intra-observer κ = 0.82–0.91; inter-observer κ = 0.81–0.86). Independent risk factors included unilateral isolated endplate (1 point), bilateral isolated endplates (2 points), split-type fracture (2 points), endplate defect ≥3 mm (2 points), and intervertebral instability ≥10° (1 point). The optimal cutoff score was 1.5 points; patients with scores of ≥2 had a significantly increased risk of revision surgery after BKP (p < 0.001). The area under the ROC curve for the risk score was 0.870. Conclusions The novel CT-based endplate classification is simple and reliable. A scoring system combining isolated endplate, split-type fracture, endplate defect, and vertebral instability can predict reoperation risk and guide surgical decision-making in patients with severe OVF.