TY - JOUR
T1 - Tibial tuberosity osteotomy for patellofemoral realignment alters tibiofemoral kinematics
AU - Mani, Saandeep
AU - Kirkpatrick, Marcus S.
AU - Saranathan, Archana
AU - Smith, Laura G.
AU - Cosgarea, Andrew J.
AU - Elias, John J.
N1 - Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2011/5
Y1 - 2011/5
N2 - Background: Tibial tuberosity realignment surgery is performed to improve patellofemoral alignment, but it could also alter tibiofemoral kinematics. Hypothesis: After tuberosity realignment in the malaligned knee, the reoriented patellar tendon will pull the tuberosity back toward the preoperative position, thereby altering tibiofemoral kinematics. Study Design: Controlled laboratory study. Methods: Ten knees were tested at 40°, 60°, and 80° of flexion in vitro. The knees were loaded with a quadriceps force of 586 N, with 200 N divided between the medial and lateral hamstrings. The position of the tuberosity was varied to represent lateral malalignment, with the tuberosity 5 mm lateral to the normal position; tuberosity medialization, with the tuberosity 5 mm medial to the normal position; and tuberosity anteromedialization, with the tuberosity 10 mm anterior to the medial position. Tibiofemoral kinematics were measured using magnetic sensors secured to the femur and tibia. A repeated measures analysis of variance with a post hoc Student-Newman-Keuls test was used to identify significant (P <.05) differences in the kinematic data between the tuberosity positions at each flexion angle. Results: Medializing the tibial tuberosity primarily rotated the tibia externally compared with the lateral malalignment condition. The largest average increase in external rotation was 13° at 40° of flexion, with the increase significant at each flexion angle. The varus orientation also increased significantly by an average of 1.5° at 40° and 80°. The tibia shifted significantly posteriorly at 40° and 60° by an average of 4 mm and 2 mm, respectively. Shifting the tuberosity from the medial to the anteromedial position translated the tibia significantly posteriorly by an average of 2 mm at 40°. Conclusion: After tibial tuberosity realignment in the malaligned knee, the altered orientation of the patellar tendon alters tibiofemoral kinematics. Clinical Relevance: The kinematic changes reduce the correction applied to the orientation of the patellar tendon and could alter the pressure applied to tibiofemoral cartilage.
AB - Background: Tibial tuberosity realignment surgery is performed to improve patellofemoral alignment, but it could also alter tibiofemoral kinematics. Hypothesis: After tuberosity realignment in the malaligned knee, the reoriented patellar tendon will pull the tuberosity back toward the preoperative position, thereby altering tibiofemoral kinematics. Study Design: Controlled laboratory study. Methods: Ten knees were tested at 40°, 60°, and 80° of flexion in vitro. The knees were loaded with a quadriceps force of 586 N, with 200 N divided between the medial and lateral hamstrings. The position of the tuberosity was varied to represent lateral malalignment, with the tuberosity 5 mm lateral to the normal position; tuberosity medialization, with the tuberosity 5 mm medial to the normal position; and tuberosity anteromedialization, with the tuberosity 10 mm anterior to the medial position. Tibiofemoral kinematics were measured using magnetic sensors secured to the femur and tibia. A repeated measures analysis of variance with a post hoc Student-Newman-Keuls test was used to identify significant (P <.05) differences in the kinematic data between the tuberosity positions at each flexion angle. Results: Medializing the tibial tuberosity primarily rotated the tibia externally compared with the lateral malalignment condition. The largest average increase in external rotation was 13° at 40° of flexion, with the increase significant at each flexion angle. The varus orientation also increased significantly by an average of 1.5° at 40° and 80°. The tibia shifted significantly posteriorly at 40° and 60° by an average of 4 mm and 2 mm, respectively. Shifting the tuberosity from the medial to the anteromedial position translated the tibia significantly posteriorly by an average of 2 mm at 40°. Conclusion: After tibial tuberosity realignment in the malaligned knee, the altered orientation of the patellar tendon alters tibiofemoral kinematics. Clinical Relevance: The kinematic changes reduce the correction applied to the orientation of the patellar tendon and could alter the pressure applied to tibiofemoral cartilage.
KW - patellofemoral malalignment
KW - tibiofemoral kinematics
KW - tuberosity osteotomy
KW - tuberosity realignment
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U2 - 10.1177/0363546510390188
DO - 10.1177/0363546510390188
M3 - Article
C2 - 21233407
AN - SCOPUS:79955703223
VL - 39
SP - 1024
EP - 1031
JO - American Journal of Sports Medicine
JF - American Journal of Sports Medicine
SN - 0363-5465
IS - 5
ER -