A Comparison of Percutaneous Kyphoplasty with High-Viscosity and Low-Viscosity Bone Cement for Treatment of Osteoporotic Vertebral Compression Fractures: A Retrospective Study oleh Wenhao Wang MM, Hao Liu MM, Zhikai Wu MM, Yun Teng MM, Yixue Huang MM, Tao Liu MD, PhD, Huilin Yang MD, PhD