Intramedullary and Extramedullary Combined Alignment System for Tibial Component Placement in Total Knee Arthroplasty

ABSTRACT

PURPOSE: The purpose of this study is to assess the usefulness of combined intramedullary and extramedullay tibial resection guide system. MATERIALS AND METHODS: 277 consecutive total knee arthroplasties were performed using three different alignment systems.: extramedullary system(group 1 ; 89 cases) , intramedullary system(group 2;134 cases), combined system(group 3;54 cases). We compared the differences of these groups in terms of preoperative femorotibial angle, postoperative femorotibial angle and postoperative tibial component alignment angle, respectively. RESULTS: Preoperatively, the three groups were similar in diagnosis, patient age, and preoperative femorotibial angle(p>0.05). Postoperative tibial component alignment angle and femorotibial angle were similar in each group(p>0.05). The optimal tibial component alignment angle was defined within 2 degree of the 90 degree and it was achieved in 51.7% in group 1, 47.8% in group 2 and 59.3% in group 3(p>0.05). The the optimal femorotibial angle was defined by the range from valgus 5 degrees+/-2 and it was achieved in 54.5% in Group 1, 54.5% in Group 2 and 55.6% in Group 3(p>0.05). CONCLUSION: This study demonstrated that the accuracy of the extramedullary system, intramedullary system, and combination system for tibial resection were similar. So the combination system can be one of the acceptable method for cutting the proximal tibia, because it utilizes the strength of the extramedullary system as well as the intramedullary system.