Accuracy Of Tibial Extramedullary Localization In Patients With Knee Varus In Total Knee Arthroplasty

Objective: to explore the anatomic landmarks closest to the center of ankle joint,and to provide a good basis for accurate positioning of coronal tibial force line in total knee arthroplasty(TKA)Methods: 32 patients with varus knee arthroplasty(knee varus angle in the range of 6-15 °)were selected.The body surface markers such as tibial spine,lateral edge of tibialis anterior muscle tendon,dorsal pedis artery and axis of the second metatarsal shaft were marked on the skin surface The results were statistically analyzed to determine the most ideal anatomical mark of ankle joint center point.Results: The average deviation((?) ± s)from the projection point of each body surface marker on the talus to the center of the bone apex was:(5.03 ± 3.11)mm at the projection point A of the tibial anterior ridge,(7.38 ± 4.30)mm at the projection point B of the lateral edge of the tibial anterior muscle tendon,(-4.30 ± 2.78)mm at the projection point C of the dorsal pedis artery,and(6.07 ± 3.53)mm at the projection point D of the axis of the second metatarsal shaft.The dorsalis pedis artery and anterior tibial spine were close to the ankle joint center,and the difference between the two groups was statistically significant(P < 0.05).Conclusion: 1.The dorsalis pedis artery as the intersection point with the transverse striation of the ankle is the body surface location mark of the ankle joint in the extramedullary localization of total knee arthroplasty,which is the closest to the theoretical ankle joint center among the above four body surface anatomical markers.2.It is theoretically the most accurate,convenient and feasible to fluoroscopy and mark the center of ankle joint before surgical disinfection.