Intramedullary versus extramedullary tibial resection in total knee replacement

This study was performed to compare the accuracy of intramedullary versus extramedullary tibial resection in 54 total knee arthroplasties. An intramedullary guide was used in 27 patients[group 1] and an extramedullary guide was used in another 27 patients [group 2]. Femorotibial angles were measured postoperatively with group 1 averaging 7.52-degree valgus in 25 out of 27 patients and 1.5-degree varus in 2 out of 27 patients. In group 2, the average femorotibial angles were 6.92-degree valgus in 26 out of 27 patients and 1.0-degree varus in one patient. The tibial component alignment angles averaged 89.78-degree varus in group I versus 90.85- valgus in group 2. However, 77.8% of the patients were aligned within the range of 7 +/- 2-degree valgus femorotibial angle in group 1 versus 62.96% in group 2