Risk factors of adjacent vertebral collapse after percutaneous vertebroplasty for osteoporotic vertebral fracture in postmenopausal women

Kenji Takahara, Mikio Kamimura, Hideki Moriya, Ryohei Ashizawa, Tsuyoshi Koike, Yohei Hidai, Shota Ikegami, Yukio Nakamura, Hiroyuki Kato

Recently percutaneous vertebroplasty (PVP) was frequently performed for treatment of osteoporotic vertebral fractures (VFs). It is widely accepted that new compression fractures tend to occur adjacent to the vertebral bodies, typically within a month after PVP. To determine the risk factors among several potential predictors for de novo VFs following PVP in patients with osteoporosis. We retrospectively screened the clinical results of 88 patients who had been treated by PVP. Fifteen cases were excluded due to non-union. Of the remaining 73 patients, 19 (26.0 %) later returned with pain due to a new vertebral compression fracture. One patient with a non-adjacent fracture and 2 patients with adjacent factures occurring 3 months later were excluded from the study. The 9 male patients were excluded to avoid gender bias. Ultimately, we divided the 61 remaining postmenopausal female patients (mean age: 78.9 years) into the collapse group (14 patients) who had experienced adjacent vertebral collapse after PVP and the non-collapse group (47 patients) who had not. Logistic regression analysis was performed to identify the risk factors for new VFs after PVP. All 14 cases of adjacent VF occurred within the first month after surgery. The collapse group had significantly advanced age, higher urinary N-terminal cross-linking telopeptide of type I collagen, and lower lumbar and hip bone mineral density (BMD) scores as compared with the non-collapse group. The odds ratios for age, lumbar, total hip, femoral neck, and trochanteric BMD were 4.5, 8.2, 4.5, 7.2, and 9.6, respectively. Positive likelihood ratios suggested that age more than 85 years, lumbar BMD less than 0.700 [-2.6SD], total hip BMD less than 0.700 [-1.8SD], neck BMD less than 0.600 [-2.1], and trochanter BMD less than 0.600 conferred an elevated risk of adjacent VF. Our study revealed that advanced age and decreased lumbar and hip BMD scores most strongly indicated a risk of adjacent VF following PVP.