PURPOSE: The aim of this study was to analyse the clinical and radiographic results of 208 e-Motion® posterior cruciate-retaining, mobile bearing prostheses (BBraun-Aesculap, Tuttlingen, Germany) fitted using computer navigation, for knee osteoarthritis with a genu varum greater than 10°. METHODS: One hundred ninety-two patients were operated on with 208 e-Motion® prostheses fitted, between January 2006 and December 2011, using the OrthoPilot® computer navigation system. Average pre-operative IKS score was 70 ± 27 points (6-143) with a function score of 38 ± 20.5 (0-90) and a knee score of 32.5 ± 13 (0-63). Average flexion was 116.5° ± 13° (65-140°). Average pre-operative HKA angle was 166° ± 3° (154-169°). RESULTS: 2Results are available for 134 patients, with a total of 150 knees operated on (38 lost to follow-up and 20 deceased). Average follow-up was 104.5 months (60-116 months). On last follow-up, the average IKS was 180 ± 22 points (95-200) with 86.5 ± 16 points (25-100) for the function score and 93.5 ± 8 points (55-100) for the knee score. Knee flexion was 116° ± 10.5° (80-135°) and average HKA angle was 179° ± 2° (175-184°). The pre-operative objective was achieved in 90.5% of knees. CONCLUSION: The e-Motion® mobile bearing posterior cruciate-retaining prosthesis, fitted using computer navigation, offers excellent results after an average of 8.5 years follow-up. These results are at least equivalent, even superior, to those of the posterior-stabilised prostheses usually used for this type of deformity.