Microstructure and biomechanical characteristics of bone substitutes for trauma and orthopaedic surgery

Seven calcium phosphate cements (BoneSource？, Calcibon？, ChronOS？, Eurobone？, HydroSet？, Norian SRS？, and Ostim？), one calcium sulphate cement (MIIG？ X3), and one bioactive glass cement (Cortoss？) were tested. Structural characteristics were measured by micro-CT scanning. Compression strength and stiffness were determined following unconfined compression tests.Each bone substitute had unique characteristics. Mean total porosity ranged from 53% (Ostim？) to 0.5% (Norian SRS？). Mean pore size exceeded 100 μm only in Eurobone？ and Cortoss？ (162.2 ± 107.1 μm and 148.4 ± 70.6 μm, respectively). However, 230 μm pores were found in Calcibon？, Norian SRS？, HydroSet？, and MIIG？ X3. Connectivity density ranged from 27/cm3 for HydroSet？ to 0.03/cm3 for Calcibon？. The ultimate compression strength was highest in Cortoss？ (47.32 MPa) and lowest in Ostim？ (0.24 MPa). Young's Modulus was highest in Calcibon？ (790 MPa) and lowest in Ostim？ (6 MPa).The bone substitutes tested display a wide range in structural properties and compression strength, indicating that they will be suitable for different clinical indications. The data outlined here will help surgeons to select the most suitable products currently available for specific clinical indications.Treatment of bone defects is a continuous challenge in skeletal trauma and orthopaedic trauma surgery. Bone graft represents the second most common transplanted tissue, with blood being number one [1]. Worldwide, more than 2.2 million bone grafting procedures are performed annually for the repair of bone defects in orthopaedic traumatology, neurosurgery, and dentistry [2-4]. Approximately 10% of all skeletal reconstructive surgical interventions require bone grafting [4]. Large defects resulting from, among others, trauma, infection, or tumor resection often do not heal spontaneously, and require surgical intervention. In addition, the treatment of posttraumatic skeletal complications such as delayed unions, nonunions, or malunions freque