Mechanical evaluation of potential ceramic implant materials for use in minimally invasive anterior interbody fusion

While autologous bone grafts are highly suitable for use in spinal arthrode sis, their use is also associated with problems (traumatization, complicati ons). Ceramic bone substitute materials provide an attractive alternative f or lumbar interbody spinal fusion. The aim of the present study was to inve stigate the mechanical properties of various types of ceramic using a speci fic fusion method. Ten specimens each of 7 different types of ceramic were tested using a hydraulic testing machine with two different sample holders: polyurethane foam (mechanical properties similar to cancellous bone) and a luminium. The parameters axial compression and axial torque were investigat ed. With the polyurethane foam holders, none of the ceramic implants failed und er compression, while under axial rotation, two types of ceramic failed. Wi th the aluminium holders, 3 ceramics showed no failure up to 25 kN under co mpression, while under torsion all the ceramics failed. One type of ceramic showed specific fracture properties with a higher load-bearing capacity af ter failure in comparison with all the other types studied.