Computer-assisted navigation system (CAS) in total knee arthroplasty (TKA) has been shown to improve mechanical alignment and prosthesis positioning as compared to conventional TKA. However, the evidence with regard to whether CAS-TKA has better patient function over conventional TKA is not clear. This systematic review and meta-analysis compares functional outcomes of CAS vs conventional TKA at longer follow-up periods.
This study was conducted in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. PubMed, Embase, gray literature, and clinicaltrials.gov were searched up to April 30, 2018. All prospective original studies (only level 1 and 2) that compared functional outcomes of CAS-TKA vs conventional TKA, with minimum 2-year follow-up, were included. The research question and eligibility criteria were established a priori. Pertinent data were extracted and random-effects model was used.
A total of 18 studies with 3060 knees were included; of which 1538 underwent TKA with CAS and 1522 underwent conventional TKA. Studies were grouped based on the follow-up reported into: (1) ≥2 years to <5 years; (2) ≥5 years to <8 years; (3) >8 years. Pooled mean Western Ontario and McMaster Universities Osteoarthritis Index scores (P < .001) and Knee Society Score-function score (P = .03) were better in the CAS-TKA group in the 5- to 8-year follow-up. For the remaining follow-ups, there was no difference between the 2 groups.
The meta-analysis concluded that there is limited evidence that CAS-TKA improves functional outcomes at 5- to 8-year follow-up as measured by Western Ontario and McMaster Universities Osteoarthritis Index and Knee Society Score-function scores. More prospective studies with larger sample size and longer-term follow-up are required to support the trend toward better functional outcomes with CAS.