Postoperative femoral anteroposterior position while standing correlates with the posterior tibial slope and posterior femoral condylar offset in medial pivot total knee arthroplasty

2021 ◽  
pp. 1-14
Author(s):  
Yuki Takahashi ◽  
Takashi Sato ◽  
Tomoharu Mochizuki ◽  
Satoshi Watanabe ◽  
Osamu Tanifuji ◽  
...  

BACKGROUND: After total knee arthroplasty (TKA), the femur tends to be located posteriorly under weight-bearing (WB) conditions, and a paradoxical femoral anterior motion occurs, leading to joint instability. OBJECTIVE: We aimed to clarify factors which affect the postoperative femoral anteroposterior position relative to the tibia under WB conditions (A-P position) in medial pivot (MP) TKA. METHODS: Among 126 knees (81 women) with primary TKA using MP prosthesis for varus osteoarthritic knees, 70 knees had cruciate-retaining inserts (CR) with the reduced conformity and 56 knees had cruciate-substituting inserts (CS) with the full conformity. Using the three-dimensional (3D) assessment system, the associations between the A-P position and the factors including pre- and postoperative lower extremity alignment, component positions, and posterior femoral condylar offset (PCO), were assessed regarding the type of inserts. RESULTS: Significant correlations were seen between the A-P position and posterior tibial slope (PTS), medial PCO, and lateral PCO. Regarding the difference between the two inserts, the PTS, medial PCO, and lateral PCO significantly correlated with the A-P position in the CR, but only the PTS correlated in the CS. CONCLUSIONS: The increased PTS and decreased PCO were the dominant factors for the A-P position in MP TKA.

2020 ◽  
Vol 9 (11) ◽  
pp. 761-767
Author(s):  
Masaru Hada ◽  
Hideki Mizu-uchi ◽  
Ken Okazaki ◽  
Koji Murakami ◽  
Takao Kaneko ◽  
...  

Aims This study aims to investigate the effects of posterior tibial slope (PTS) on knee kinematics involved in the post-cam mechanism in bi-cruciate stabilized (BCS) total knee arthroplasty (TKA) using computer simulation. Methods In total, 11 different PTS (0° to 10°) values were simulated to evaluate the effect of PTS on anterior post-cam contact conditions and knee kinematics in BCS TKA during weight-bearing stair climbing (from 86° to 6° of knee flexion). Knee kinematics were expressed as the lowest points of the medial and lateral femoral condyles on the surface of the tibial insert, and the anteroposterior translation of the femoral component relative to the tibial insert. Results Anterior post-cam contact in BCS TKA was observed with the knee near full extension if PTS was 6° or more. BCS TKA showed a bicondylar roll forward movement from 86° to mid-flexion, and two different patterns from mid-flexion to knee extension: screw home movement without anterior post-cam contact and bicondylar roll forward movement after anterior post-cam contact. Knee kinematics in the simulation showed similar trends to the clinical in vivo data and were almost within the range of inter-specimen variability. Conclusion Postoperative knee kinematics in BCS TKA differed according to PTS and anterior post-cam contact; in particular, anterior post-cam contact changed knee kinematics, which may affect the patient’s perception of the knee during activities. Cite this article: Bone Joint Res 2020;9(11):761–767.


Author(s):  
O-Sung Lee ◽  
Jangyun Lee ◽  
Myung Chul Lee ◽  
Hyuk-Soo Han

AbstractThe posterior tibial slope (PTS) is usually adjusted by less than 5 degrees, without considering its individual difference, during posterior cruciate-substituting (PS) total knee arthroplasty (TKA). The effect of these individual changes of PTS would be important because clinical results depending on postoperative PTS were reported conflictingly. We investigated the effect of the change in PTS on the postoperative range of motion (ROM) and clinical scores after PS TKA. We retrospectively reviewed 164 knees from 107 patients who underwent PS TKA with a 2-year follow-up. We analyzed the preoperative and postoperative PTS, ROM, visual analog scale pain scale, Western Ontario and McMaster University Index (WOMAC), Hospital for Special Surgery Knee Score, Knee Society Score, and Forgotten Joint Score (FJS). The association of the absolute change in PTS with ROM and clinical scores was analyzed using correlation analysis and multiple regression analysis. As a result, the mean PTS and mean ROM changed from 9.6 ±  3.4 and 120.1 ±  15.4 degrees preoperatively to 2.0 ±  1.3 and 128.4 ±  9.3 degrees postoperatively, and the mean PTS change was 7.6 ±  3.5 degrees. The PTS change had no statistically significant association with the postoperative ROM and clinical scoring systems, although it did have a weak positive correlation with WOMAC function, No 10 (difficulty in rising from sitting) (correlation coefficient = 0.342, p = 0.041), and moderate positive correlation with the FJS, No. 6 (awareness when climbing stairs) (correlation coefficient = 0.470, p = 0.001). The authors concluded that the amount of change in PTS did not affect the postoperative ROM and clinical scores, although proximal tibial resection with a constant target of PTS resulted in individually different changes in the PTS after PS TKA,


2018 ◽  
Vol 33 (12) ◽  
pp. 3778-3782.e1 ◽  
Author(s):  
Toshitaka Fujito ◽  
Tetsuya Tomita ◽  
Takaharu Yamazaki ◽  
Kosaku Oda ◽  
Hideki Yoshikawa ◽  
...  

Orthopedics ◽  
2019 ◽  
Vol 43 (1) ◽  
pp. e21-e26
Author(s):  
James L. Howard ◽  
Mina W. Morcos ◽  
Brent A. Lanting ◽  
Lyndsay E. Somerville ◽  
James P. McAuley

2019 ◽  
Vol 16 (1) ◽  
pp. 25-30
Author(s):  
Takenori Tomite ◽  
Hidetomo Saito ◽  
Hiroaki Kijima ◽  
Kimio Saito ◽  
Hiroshi Tazawa ◽  
...  

2008 ◽  
Vol 23 (4) ◽  
pp. 586-592 ◽  
Author(s):  
Jae Ho Yoo ◽  
Chong Bum Chang ◽  
Kwang Sook Shin ◽  
Sang Cheol Seong ◽  
Tae Kyun Kim

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