Accelerometer-based navigation (ABN) is a novel navigation system that attempts to combine the accuracy of computer-assisted surgery (CAS) with the familiarity of conventional instrumentation (CON). No studies have compared the clinical outcomes of this new technology with existing techniques to date.
From July 2013 to April 2014, 152 consecutive patients (152 knees) underwent total knee arthroplasty using ABN (n = 38), CAS (n = 38), or CON (n = 76). We prospectively matched the groups in a 1:1:2 ratio for age, gender, body mass index, preoperative range of motion, Knee Society Score, Oxford Knee Score, Short-Form 36 Physical and Mental Component Scores, and preoperative deformity using preoperative data in isolation, thus controlling for potential confounding factors. All patients were prospectively followed for 2 years.
The ABN and CAS groups had a significantly improved mean mechanical axis (P = .018), femoral (P = .050) and tibial component alignment (P = .008) compared to the CON group. There were significantly less mechanical axis outliers in the ABN and CAS groups (P = .034). The duration of surgery for the ABN group (83.9 ± 21 min) was significantly shorter than the CAS group (101 ± 11 min; P < .001) but similar to the CON group (76.6 ± 17 min; P = .131). There was no significant difference in functional outcomes, quality of life measures or satisfaction rates between the 3 groups at 2 years (P > .05).
Although bone cuts were as accurate as CAS and operation time was similar to CON, the use of ABN failed to demonstrate any advantages in clinical outcomes following total knee arthroplasty at 2 years follow-up.