Does computer-assisted surgery influence survivorship of cementless total knee arthroplasty in patients with primary osteoarthritis? A 10-year follow-up study.

PURPOSE: Computer-assisted surgery (CAS) has been proposed to improve the performance of total knee arthroplasty (TKA) by reducing implant mal-position and mechanical axis mal-alignment. However, no clinical study has been performed to evaluate whether CAS improves survivorship of cementless TKA at long-term follow-up. This prospective and comparative study evaluated the outcome and survivorship of a cementless rotating mobile-bearing TKA performed with or without CAS at a minimum 10-year follow-up.

METHODS: A continuous series of 138 TKA (SCORE® , Amplitude, Valence, France) comparing 87 CAS TKA versus 51 conventional mechanical technique (MECA) TKA was prospectively included in our total joint registry.

RESULTS: At 10.5 years after implantation, 95 TKA (59 CAS and 36 MECA TKA) were evaluated. No significant difference was detected in the clinical outcome and mechanical axis between the two groups. The overall 10-year survivorship using revision for any reason as end-point was 91 ± 5 % without significant difference detected between the two groups [86 ± 10 % in the MECA group and 94 ± 5 % in the CAS group (n.s.)]. Using aseptic loosening as end-point, the 10-year survivorship was 100 % in both groups. Using secondary patellar resurfacing as end-point, the 10-year survivorship was significantly higher in the CAS than in MECA group (100 and 85 ± 15 %, respectively; p = 0.0039).

CONCLUSION: With no implant aseptic loosening or mechanical failure at 10.5 years after implantation, the cementless rotating mobile-bearing SCORE® TKA demonstrated favourable survivorship without influence of CAS. However, CAS might influence TKA survivorship by limiting secondary patellar resurfacing.

LEVEL OF EVIDENCE: Therapeutic, Level II.