Extramedullary versus intramedullary tibial alignment guides for total knee arthroplasty.

This retrospective study evaluated whether intramedullary or extramedullary tibial alignment guides are more accurate in assuring correct tibial component positioning in total knee arthroplasties (TKAs). Fifty-five TKAs were performed with the only difference being whether an intramedullary (31) or extramedullary (24) cutting guide was used. Pre- and postoperative tibiofemoral angle, tibial component alignment angle, and femoral component alignment angles were measured and the results were statistically analyzed. We also performed a subgroup analysis on the preoperative varus knees to determine if the presence of a varus deformity would have better results with either the intramedullary or extramedullary cutting guide. The 2-sample t test was used to compare the results of the two groups. The results showed no statistical difference in alignment of the tibial component when using the intramedullary or extramedullary guides.