[Are computer assisted total knee replacements more accurately placed? A meta-analysis of comparative studies].

Computer-assisted surgery (CAS) has become established in many hospitals throughout the world, especially in the form of computer navigation for total knee replacement (TKR). Analysis of the studies available revealed 18 comparative studies examining the precision of implantation of knee endoprostheses following CAS and after implantation by the conventional technique. In a meta-analysis of 13 studies in which the same safe zone of +/-3 from neutral alignment was defined for the leg axis, a total of 1,784 TKR were performed. In the group of patients in whom the conventional technique was used, 75.6% (654/865) of TKR were implanted within the safe zone. In the CAS group 93.9% (863/919) of the prostheses were implanted within the safe zone (p<0.0001). The differences between the groups were statistically significant in 11 of the 13 studies, and the difference between groups for the entire patient population is highly significant. Only limited clinical results were ascertained in these comparative studies; there were no great differences between the treatment groups in clinical course.