Intramedullary versus extramedullary alignment guides on total knee arthroplasty: a meta-analysis.

Aim: A meta-analysis concentrated on the effect of intramedullary and extramedullary systems on total knee arthroplasty. Method: Potential academic articles were identified from Cochrane Library, Medline, PubMed, Embase, ScienceDirect, CNKI, WanFang, VIP and other databases. The STATA version was used to analyze the pooled data. Results: There are obvious significant differences in drainage volume and transfusion rate. There was no significant difference in lower limb coronal alignment, coronal and sagittal alignment of the femoral component, operation time, postoperative knee score and complications. Conclusion: Our meta-analysis shows that the alignment of the extramedullary distal femur osteotomy is as accurate as intramedullary systems. Furthermore, extramedullary distal femur osteotomy without invading the femoral medullary cavity could reduce postoperative bleeding and the transfusion rate. Furthermore, research is required to test the robustness of our findings when more data is available and by undertaking both Bayesian and frequentist methods. When more data are available, the heterogeneity can be further explored through sensitivity analysis, and the available data can be combined to verify the hypothesis.