A different fixation of the femoral component in total knee arthroplasty may lead to preservation of femoral bone stock

Author(s):  
M Barink ◽  
N Verdonschot ◽  
M de Waal Malefijt

Good femoral bone stock is important for the stability of the femoral component in revision knee arthroplasty. However, the primary total knee replacement (TKR) may cause significant loss of bone stock in the distal anterior femur. Earlier stress-induced bone remodelling simulations have suggested that a completely debonded component may save bone stock in the distal anterior region. However, these simulations did not consider the fixation of a debonded implant and possible secondary effects of micromotions and osteolysis at the interface. The current study tries to combine the preservation of bone stock with adequate component fixation. Different bone remodelling simulations were performed around femoral knee components with different sizes of bonding area and different friction characteristics of the debonded area. The fixation of the femoral component with different bonding characteristics is quantified with calculated implant-bone interface stresses. The results show that a bonded femoral component with a debonded inner side of the anterior flange may significantly reduce bone resorption in the endangered distal anterior femur, without jeopardizing the fixation of the femoral implant. This effect may be obtained in vivo by using a femoral component with a highly polished inner side of the anterior flange.

2021 ◽  
Author(s):  
Kosei Ishigaki ◽  
Hideyuki Aoki ◽  
Ryo Takamatsu ◽  
Yuji Nishiwaki ◽  
Hiroshi Takahashi ◽  
...  

Abstract Background: The utility of a bi-cruciate retaining total knee arthroplasty (BCR-TKA) is uncertain. In this study, we performed an in vivo kinematic analysis of squat motion on level ground and on a downward slope in patients treated with BCR-TKA to examine the value of anterior cruciate ligament (ACL) preservation.Methods: The subjects were ten valgus knees that underwent TKA (BCR: 5 knees, CR: 5 knees) at our hospital. We evaluated in vivo kinematics of the knee using fluoroscopy and investigated the femoral component translation relative to the tibial component from extension to maximum flexion, and the rotation angle between the components under the two conditions. Statistical analysis was conducted by Mann-Whitney U test to compare the rotational angle, the location of lateral and medial contact points per flexion angle. Differences in these parameters between the BCR and CR groups across the flexion angles were compared by repeated measures ANOVA.Results: Rotation of the femoral component to the tibial component occurred gradually as flexion continued. On level ground, lateral rotation at 0° to 120° flexion was 14.5±1.95° in the BCR group and 7.9±0.47° in the CR group. Medial translation was 4.1±1.73mm in the BCR group and 2.5±1.64mm in the CR group, and lateral translation was 13.2±1.6mm in the BCR group and 7.1±1.74mm in the CR group. On a forward slope, lateral rotation was 12.7±1.45° in the BCR group and 7.57±0.47° in the CR group. Medial translation was 5.87±1.78mm in the BCR and 2.9±0.81mm in the CR, and lateral translation was 13.6±1.84mm in the BCR and 7.4±0.96mm in the CR.Conclusion: An in vivo kinetics analysis of deep flexion motion was conducted on level ground and on a forward slope to stress the ACL. Under both conditions, kinetics close to screw home movement were found in the BCR group and rotation was significantly larger than that in the CR group. The medial contact point between components was located significantly more anterior in the BCR group. In conclusion, BCR-TKA was found to have in vivo kinetics close to those of a normal knee, in comparison with CR-TKA.


Author(s):  
Jason D. Tegethoff ◽  
Rafael Walker-Santiago ◽  
William M. Ralston ◽  
James A. Keeney

AbstractIsolated polyethylene liner exchange (IPLE) is infrequently selected as a treatment approach for patients with primary total knee arthroplasty (TKA) prosthetic joint instability. Potential advantages of less immediate surgical morbidity, faster recovery, and lower procedural cost need to be measured against reoperation and re-revision risk. Few published studies have directly compared IPLE with combined tibial and femoral component revision to treat patients with primary TKA instability. After obtaining institutional review board (IRB) approval, we performed a retrospective comparison of 20 patients treated with IPLE and 126 patients treated with tibial and femoral component revisions at a single institution between 2011 and 2018. Patient demographic characteristics, medical comorbidities, time to initial revision TKA, and reoperation (90 days, <2 years, and >2 years) were assessed using paired Student's t-test or Fisher's exact test with a p-value <0.01 used to determine significance. Patients undergoing IPLE were more likely to undergo reoperation (60.0 vs. 17.5%, p = 0.001), component revision surgery (45.0 vs. 8.7%, p = 0.002), and component revision within 2 years (30.0 vs. 1.6%, p < 0.0001). Differences in 90-day reoperation (p = 0.14) and revision >2 years (p = 0.19) were not significant. Reoperation for instability (30.0 vs. 4.0%, p < 0.001) and infection (20.0 vs. 1.6%, p < 0.01) were both higher in the IPLE group. IPLE does not provide consistent benefits for patients undergoing TKA revision for instability. Considerations for lower immediate postoperative morbidity and cost need to be carefully measured against long-term consequences of reoperation, delayed component revision, and increased long-term costs of multiple surgical procedures. This is a level III, case–control study.


2011 ◽  
Vol 26 (2) ◽  
pp. 268-273 ◽  
Author(s):  
Hiroki Watanabe ◽  
Ryuichi Gejo ◽  
Yoshikazu Matsuda ◽  
Ichiro Tatsumi ◽  
Kazuo Hirakawa ◽  
...  

The Knee ◽  
2021 ◽  
Vol 30 ◽  
pp. 1-8
Author(s):  
Naoki Nakano ◽  
Yuichi Kuroda ◽  
Toshihisa Maeda ◽  
Koji Takayama ◽  
Shingo Hashimoto ◽  
...  

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