In vivo kinematics of gait in posterior-stabilized and bicruciate-stabilized total knee arthroplasties using image-matching techniques.

PURPOSE: This study aimed to evaluate the effects of two types of total knee arthroplasty (TKA) designs: posterior-stabilized (PS) and bicruciate-stabilized (BCS) on in vivo kinematics during gait.

METHODS: Continuous X-ray images of the gait were taken using a flat panel detector for 23 PS and BCS TKAs. We analyzed the tibiofemoral implant flexion angle, anteroposterior (AP) translation, axial rotation, and anterior/posterior cam-post contact using image-matching techniques.

RESULTS: Double knee actions were demonstrated for the PS and BCS design (35 and 61%, respectively, p = 0.08). The tibiofemoral AP positions were significantly more posterior at peak extension (- 1.7 ± 2.2 and 1.0 ± 2.5 mm, respectively, p < 0.01) and anterior at peak flexion (1.3 ± 2.3 and - 0.8 ± 2.8 mm, respectively, p = 0.01) for the PS design than for the BCS design, with a significant difference in AP translation (3.0 ± 3.9 mm anterior and 1.7 ± 2.8 mm posterior, respectively, p < 0.01). Anterior/posterior tibial post contacts were found in 83/4% and 74/30% for the PS and BCS designs, respectively, with a significant difference in posterior contact (p = 0.72/0.04, respectively).

CONCLUSION: The knee flexion pattern, tibiofemoral AP translation, axial rotation, and cam-post contact during gait varied, depending on the type of implant, the PS and BCS designs.