An updated meta-analysis comparing complications, functional, clinically relevant and radiological outcomes of accelerometer based portable navigation and conventional technique of total knee arthroplasty.

Introduction: Since previous studies, including small-scale meta-analyses comparing accelerometer-based portable navigation (APN-TKA) and conventional techniqueof total knee arthroplasty (CONV-TKA), have reported divergent results, there is a need for an updated meta-analysis to compare complications, functional outcomes, clinically relevant outcomes and radiographic alignment of components. Methods: This meta-analysis was conducted as per PRISMA guidelines. Randomised controlled trials, and non-randomised comparative cohort studies in English language on primary TKA were included. The complications compared were Deep Vein Thrombosis (DVT), Pulmonary Embolism (PE), infection, manipulation under anaesthesia (MUA) for postoperative knee stiffness, re-operation and mortality. The functional outcomes compared were the Knee Society Knee Score, Knee Society Score function, Oxford Knee Score, Knee Injury and Osteoarthritis Outcome Score and Western Ontario and McMaster Universities Arthritis Index. The evaluated clinically relevant outcomes were surgical time, blood loss, drop in haematocrit, tourniquet time, postoperative knee flexion and complications). The number of radiological outliers; as well as the absolute values of the alignment of the overall prosthesis, femoral and tibial components in both coronal and sagittal planes, was assessed. Results: Twenty-five studies were included. Both the groups were comparable in terms of preoperative demographic features. There was no difference in complications and functional outcomes. Operation time was longer in APN-TKA (p < 0.00001) but there was no difference in rest of the clinically relevant outcomes. Restoration of the lower limb mechanical axis (p = 0.003) and coronal femoral alignment angle (p = 0.0002) was better with APN. APN also significantly reduced the risk of the odds of outliers of lower limb mechanical axis (p < 0.0001), coronal femoral alignment (p = 0.03), coronal tibial alignment (p < 0.0001) and sagittal tibial alignment (p = 0.0001). Conclusion: The improvement in the accuracy of implantation by the use of APN-TKA, as determined by the overall alignments of prosthesis, or femoral and tibial components, does not necessarily translate into lesser complications and better functional and clinical outcomes. Level of evidence: Therapeutic study, Level II.