Introduction: The Charite Mark 3 disc prosthesis has been used by the senior author for ten years. There has always been a question mark over the wear properties of the high density polyethylene spacer used in this prosthesis.

Methods: Ten patients who have received Charite implants, eight, nine and ten years ago were subjected to helical CT scanning. Slices at 3 mm. intervals were taken across the prosthetic levels. Fifteen prostheses were studied. Four clinicians, two of whom were radiologists and one a spinal fellow, assessed the CT scans against a standard protocol. Since the original heights of the prostheses were known, it was possible to measure prosthetic height and therefore get an estimate of wear. In addition, areas of osteolysis around the prostheses were estimated, again as a sign of wear.

Results: Remarkably little wear or wear debris was noted around the 15 prostheses.

Conclusions: Although this is a small series, it confirms that the medium-term performance of this prosthesis as far as wear is concerned is good.