Prospective recording of complications of conservatively and surgically treated fragility fractures of the pelvis as part of the multicenter of-pelvis study - F.C. Kohler; P. Schenk; P. Schanderl; B. Ullrich; G. Osterhoff; V. Zimmermann; M. Naisan; E. Wegner; M. Müller; F. Hartmann; K.J. Schnake; S. Klunk; et al. (Brain and Spine)