Anatomical MRI study for rotational alignment of tibial component in total knee arthroplasty / 实用医学杂志

ABSTRACT

Objective To compare the difference between a vertical line (AA) drawn to the line connecting the inner edge of the patellar tendon with the mid-point of the ending point in the posterior cruciate ligament, tibial posterior condylar line (PC), tibial plateau anterior line (AC), the maximal mediolateral distance (MMLD) and a vertical line (BB) drawn to aligning the mid-point of ending point in the posterior cruciate ligament with the medial 1 / 3 of the patellar tendon relative to the surigical transepicondylar axis (STEA) by MRI, and to explore a reliable reference to determine tibial component rotation in total knee arthroplasty , and whether it will change in knees with varus deformity. Methods Thirty healthy volunteers (Group1) and thirty osteoarthritis patients (Group2) were enrolled in this study. The angles were measured among the five tibial rotation axes and STEA after MRI. Results The angles were (-1.48 ± 2.38)°, (6.16 ± 4.53)°, (6.45 ± 5.24)° ,(5.08 ± 4.99)° and (3.24 ± 2.68)° respectively in group 1 and (-1.88 ± 2.21)°, (-3.13 ± 4.66)°, (11.13 ± 5.72)°, (4.11 ± 4.15)° and (5.12 ± 4.87)° respectively in group 2. The angle between AA and STEA was not affected by varus deformity (P > 0.05), but the others were (P < 0.05). Conclusion The angle between AA and STEA is the smallest which is used to determine tibial component rotation in knees with varus deformity is the most reliable one.