Aim: To demonstrate that a novel tricalcium phosphate bone cement (Biobon) could be effectively used to þll the dorsal metaphyseal defect after unstable distal radial fractures in the osteopenic wrist, and to conþrm with biomechanical studies that its mechanical properties were incompatible with its sole use. Methods: Compression and Biaxial ßexure testing was performed under both dry and wet conditions of physiological Saline and Ringers Lactate solutions at 37ûC. 9 female patients with a mean age of 65 years sustaining Frykman grade VIII fractures of the distal radius between 1999 and 2000 underwent open reduction and internal þxation with supplementation of the dorsal metaphyseal defect with Biobon. Results: Youngs Modulus (E) and the Ultimate compressive strength (UCS) for the two solutions were identical at 10 hours (406 MPa and 3.24 MPa respectively), reaching a maximum for Ringers Lactate solution. The Biaxial ßexure stress also reached a maximum value at 10 hours for Saline at 37û C (3.96 MPa). A signiþcant improvement of radiographic parameters were observed post-operatively (Mean volar tilt = + 1.1û; Mean radial length = 10.4mm: Mean radial inclination = 20.5û) and remained so at the time of assessment (Mean volar tilt = +2.5û; Mean radial length = 10.4 mm; Mean radial inclination = 21.8û).Conclusion: The use of a tri-calcium phosphate bone cement is an effective means of addressing the dorsal comminution sustained after unstable distal radial fractures. Its biomechanical properties precludes its sole use for the treatment of distal radial fractures.