J. M. Spencer, S. K. Chauhan, K. Sloan, A. Taylor, R. J. Beaver.
J Bone Joint Surg Br, Apr 2007; 89-B: 477 – 480
Computer navigation for Total Knee Arthroplasty is a fairly new technique which promises to deliver precise bony cuts, enhance soft-tissue balancing and improve accuracy of alignment which have the potential to translate into superior clinical outcomes.
Spencer et al have compared the component alignment in total knee replacement using a computer-navigated technique versus a conventional jig-based method. 71 patients were randomised to undergo either computer-navigated or conventional replacement. The patients were then followed up post-operatively for two years, using the Knee Society score, the SF 36 health survey, the Western Ontario and McMaster Universities osteoarthritis index, the Bartlett Patellar pain questionnaire and the Oxford knee score, to assess functional outcome. Patients were reviewed by physiotherapists, blinded to the group assigned for the study and independent of the surgeons who performed the surgical procedure.
At two years post-operatively 60 patients were available for assessment, 30 in each group and 62 patients completed a postal survey. All variables were analysed for differences between the groups either by Student’s t-test or the Mann-Whitney U test. At two years postoperatively, the frequency of mild to severe anterior pain was similar for both groups. There was no statistical difference between the Bartlett Patellar score and the Oxford knee scores. No patient in either group had undergone revision. Differences between the two groups did not reach significance for any of the outcome measures at any time point.
This study was sufficiently high in sample size to assess functional outcomes. Though the period of follow-up was short (2 years), these results are certainly a forerunner of long-term outcomes. Power analysis was not performed for the functional variables thus, these may need further analysis. Long-term outcome analysis needs to be undertaken at the end of 5 and 10-year post-operative intervals. However for the present, the functional outcomes between the computer-navigated and conventional groups appears to be no different despite the superior alignment achieved radiologically using computer-navigation procedures.