Handheld, accelerometer-based navigation versus conventional instrumentation in total knee arthroplasty: a meta-analysis.

Background: Precise and accurate alignments in total knee arthroplasty are important predictors for survivorship and functional outcomes. We aim to compare accelerometer-based navigation (ABN) to conventional instrumentation (CONV), patient-specific instrumentation (PSI) and computer-assisted surgery (CAS) in published literature.

Methods: A systematic search of publications from databases (MEDLINE, EMBASE and Cochrane) was obtained from inception to 15 August 2018. A random-effects meta-analysis was used to pool odd ratios for outliers greater than 3° for the hip-knee-ankle, coronal and sagittal femoral and tibial angles (CFA, CTA, SFA, STA). Secondary outcomes included procedural characteristics and functional outcomes.

Results: Thirteen studies, involving 1566 patients, met inclusion that compared ABN (50.2%) to CONV (49.8%) and five comparing ABN to CAS/PSI. The pooled odds ratios for percent outliers of greater than 3° from the mechanical axis for the hip-knee-ankle (relative risk 0.58, P = <0.05) and CFA (relative risk 0.42, P = 0.02) was significantly lower for ABN compared to CONV. The pooled odds ratios for CTA, SFA and STA were not significantly different. No differences were identified in comparison to PSI/CAS. There was no statistically significant difference in procedural characteristics and functional outcomes.

Conclusions: The use ABN in total knee arthroplasty is a successful method of increased precision and accuracy for the restoration of the mechanical axis. In addition, there is no significant compromise in procedural or functional outcomes.