scholarly journals Accurate implant fit and leg alignment after cruciate-retaining patient-specific total knee arthroplasty

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Jörg Arnholdt ◽  
Yama Kamawal ◽  
Konstantin Horas ◽  
Boris M. Holzapfel ◽  
Fabian Gilbert ◽  
...  
Keyword(s):  
Knee Arthroplasty ◽  
Tibial Slope ◽  
Joint Line ◽  
Patient Specific ◽  
Cruciate Retaining ◽  
Custom Made ◽  
Ankle Angle ◽  
Total Knee ◽  
Replacement System ◽  
Hip Knee Ankle Angle

Abstract Background For improved outcomes in total knee arthroplasty (TKA) correct implant fitting and positioning are crucial. In order to facilitate a best possible implant fitting and positioning patient-specific systems have been developed. However, whether or not these systems allow for better implant fitting and positioning has yet to be elucidated. For this reason, the aim was to analyse the novel patient-specific cruciate retaining knee replacement system iTotal™ CR G2 that utilizes custom-made implants and instruments for its ability to facilitate accurate implant fitting and positioning including correction of the hip-knee-ankle angle (HKA). Methods We assessed radiographic results of 106 patients who were treated with the second generation of a patient-specific cruciate retaining knee arthroplasty using iTotal™ CR G2 (ConforMIS Inc.) for tricompartmental knee osteoarthritis (OA) using custom-made implants and instruments. The implant fit and positioning as well as the correction of the mechanical axis (hip-knee-ankle angle, HKA) and restoration of the joint line were determined using pre- and postoperative radiographic analyses. Results On average, HKA was corrected from 174.4° ± 4.6° preoperatively to 178.8° ± 2.2° postoperatively and the coronal femoro-tibial angle was adjusted on average 4.4°. The measured preoperative tibial slope was 5.3° ± 2.2° (mean +/− SD) and the average postoperative tibial slope was 4.7° ± 1.1° on lateral views. The joint line was well preserved with an average modified Insall-Salvati index of 1.66 ± 0.16 pre- and 1.67 ± 0.16 postoperatively. The overall accuracy of fit of implant components was decent with a measured medial overhang of more than 1 mm (1.33 mm ± 0.32 mm) in 4 cases only. Further, a lateral overhang of more than 1 mm (1.8 mm ± 0.63) (measured in the anterior-posterior radiographs) was observed in 11 cases, with none of the 106 patients showing femoral notching. Conclusion The patient-specific iTotal™ CR G2 total knee replacement system facilitated a proper fitting and positioning of the implant components. Moreover, a good restoration of the leg axis towards neutral alignment was achieved as planned. Nonetheless, further clinical follow-up studies are necessary to validate our findings and to determine the long-term impact of using this patient- specific system.

Influence of Posterior Tibial Slope on Kinematics After Cruciate-Retaining Total Knee Arthroplasty

2018 ◽  
Vol 33 (12) ◽  
pp. 3778-3782.e1 ◽  
Author(s):  
Toshitaka Fujito ◽  
Tetsuya Tomita ◽  
Takaharu Yamazaki ◽  
Kosaku Oda ◽  
Hideki Yoshikawa ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Tibial Slope ◽  
Posterior Tibial Slope ◽  
Cruciate Retaining ◽  
Posterior Tibial ◽  
Total Knee

Reproducing the Native Posterior Tibial Slope in Cruciate-Retaining Total Knee Arthroplasty: Technique and Clinical Implications

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
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Tibial Slope ◽  
Posterior Tibial Slope ◽  
Clinical Implications ◽  
Cruciate Retaining ◽  
Posterior Tibial ◽  
Total Knee

scholarly journals Intra-Operative Experience using Magnetic Resonance Imaging (MRI) Based Patient Specific Cutting Guides during Total Knee Arthroplasty

2016 ◽  
Vol 9 (2) ◽  
pp. 22-26
Author(s):  
Ryan K. Albrecht ◽  
Alexander C.M. Chong ◽  
Paul H. Wooley ◽  
Tarun Bhargava
Keyword(s):  
Total Knee Arthroplasty ◽  
Magnetic Resonance ◽  
Knee Arthroplasty ◽  
Total Joint Replacement ◽  
Tibial Slope ◽  
New Technique ◽  
Patient Specific ◽  
Cutting Guides ◽  
Total Knee ◽  
Operative Experience

Background. The incidence of malalignment in total knee arthroplasty(TKA) using conventional instrument has beenreported as high as 25%. A relatively new TKA system involvesthe use of a preoperative magnetic resonance image(MRI) to obtain accurate implant placement more consistently.For broad acceptance of this new technique, it iscrucial to analyze the initial intra-operative experience. Thespecific aim of this study was to evaluate the initial intra-operativeexperience of a single surgeon using this new technique. Methods. A total of 15 knees (12 patients: 6 female and 6male) were reviewed from TKA procedures using the selectedmanufacturer’s patient specific cutting guides between January2011 and April 2013 at a single institution. Patient demographicand specific parameters and intra-operative alterationsof component positioning were recorded and evaluated.Results. The preoperative plan was able to predict correctly thesize of the implanted femoral component in 87% (n = 13) andtibial component in 80% (n = 12) of the cases. However, 60% (n= 9) of cases required additional intra-operative corrections onfemoral resection, and 73% (n = 11) required an additional 2 - 4mm correction on the tibial proximal resection. Twenty percent(n = 3) required additional tibial varus/valgus correction, butthere were no tibial slope corrections for any of the 15 cases. Conclusions. The initial intra-operative experience of a singlesurgeon using current patient specific cutting guides for a selectedmanufacturer to align femoral and tibial components duringTKA has raised some concerns. We agreed with previous studiesthat caution should be taken when using patient specific cuttingguides without supportive data. The findings of this study providedadditional evidence to contest the accuracy of patient specificcutting guides with respect to the initial experience of an orthopaedicsurgeon who is trained in total joint replacement. Theresults provided more evidence to assist orthopaedic surgeonsin the decision of whether to use these patient specific systemsversus conventional TKA methods. KS J Med 2016;9(2):22-26.

scholarly journals Effect of Joint Line Elevation after Posterior-stabilized and Cruciate-retaining Total Knee Arthroplasty on Clinical Function and Kinematics

2015 ◽  
Vol 128 (21) ◽  
pp. 2866-2872 ◽  
Author(s):  
Song-Jie Ji ◽  
Yi-Xin Zhou ◽  
Xu Jiang ◽  
Zhi-Yuan Cheng ◽  
Guang-Zhi Wang ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Joint Line ◽  
Posterior Stabilized ◽  
Cruciate Retaining ◽  
Total Knee

scholarly journals Outcomes and component-positioning in total knee arthroplasty may be comparable between supervised trained surgeons and their supervisor

2020 ◽  
Vol 32 (1) ◽  
Author(s):  
Kazumi Goto ◽  
Yozo Katsuragawa ◽  
Yoshinari Miyamoto
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Tibial Component ◽  
Operative Time ◽  
Case Series ◽  
Level Of Evidence ◽  
Ankle Angle ◽  
Total Knee ◽  
The Mean ◽  
Hip Knee Ankle Angle

Abstract Purpose There are concerns that malalignment in total knee arthroplasty (TKA) occurs with less experienced surgeons. This study investigates the influence of surgical experience on TKA outcomes. Materials and methods Nineteen patients (38 knees) who underwent bilateral TKA between 2011 and 2015 were included. A supervisor performed knee replacements associated with lower Knee Society Scores (KSS); trainee surgeons operated on the other knee. Knees were categorized into two groups: operations by the supervisor (group S) versus operations by trainee surgeons (group T). Range of motion (ROM), KSS, operative time, hip–knee–ankle angle, and femoral and tibial component angle were evaluated. Results The mean operative time was 92.5 min in group S and 124.2 min in group T (p < 0.01). The mean postoperative maximal flexion was 113.2° in group S and 114.2° in group T (not significant). The mean postoperative KSS was 92.9 in group S and 93.9 in group T (not significant). No significant differences between groups in terms of proportion of inliers for the hip–knee–ankle angle, femoral component angle, or tibial component angle were observed. Conclusions Although operative time was significantly longer for trainee surgeons versus the supervisor, no significant differences in ROM, KSS, or component positioning between supervisor and trainee surgeons were observed. Level of evidence IV (retrospective case series design).

scholarly journals Comparison of Kinematics in Cruciate Retaining and Posterior Stabilized for Fixed and Rotating Platform Mobile-Bearing Total Knee Arthroplasty with respect to Different Posterior Tibial Slope

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Kyoung-Tak Kang ◽  
Yong-Gon Koh ◽  
Juhyun Son ◽  
Oh-Ryong Kwon ◽  
Jun-Sang Lee ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
External Rotation ◽  
Mobile Bearing ◽  
Tibial Slope ◽  
Posterior Stabilized ◽  
Rotating Platform ◽  
Cruciate Retaining ◽  
Posterior Tibial ◽  
Total Knee

Reconstructed posterior tibial slope (PTS) plays a significant role in kinematics restoration after total knee arthroplasty (TKA). However, the effect of increased and decreased PTS on prosthetic type and design has not yet been investigated. We used a finite element model, validated using in vitro data, to evaluate the effect of PTS on knee kinematics in cruciate-retaining (CR) and posterior-stabilized (PS) fixed TKA and rotating platform mobile-bearing TKA. Anterior-posterior tibial translation and internal-external tibial rotation were investigated for PTS ranging from -3° to 15°, with increments of 1°, for three different designs of TKA. Tibial posterior translation and external rotation increased as the PTS increased in both CR and PS TKAs. In addition, there was no remarkable difference in external rotation between CR and PS TKAs. However, for the mobile-bearing TKA, PTS had less effect on the kinematics. Based on our computational simulation, PTS is the critical factor that influences kinematics in TKA, especially in the CR TKA. Therefore, the surgeon should be careful in choosing the PTS in CR TKAs.

scholarly journals Accuracy of Patient Specific Cutting Blocks in Total Knee Arthroplasty

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Naeder Helmy ◽  
Mai Lan Dao Trong ◽  
Stefanie P. Kühnel
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Computer Assisted Surgery ◽  
Tibial Slope ◽  
Patient Specific ◽  
Computer Assisted ◽  
Success Rates ◽  
Term Survival ◽  
Margin Of Error ◽  
Total Knee

Background.Long-term survival of total knee arthroplasty (TKA) is mainly determined by optimal positioning of the components and prosthesis alignment. Implant positioning can be optimized by computer assisted surgery (CAS). Patient specific cutting blocks (PSCB) seem to have the potential to improve component alignment compared to the conventional technique and to be comparable to CAS.Methods.113 knees were selected for PSI and included in this study. Pre- and postoperative mechanical axis, represented by the hip-knee-angle (HKA), the proximal tibial angle (PTA), the distal femoral angle (DFA), and the tibial slope (TS) were measured and the deviation from expected ideal values was calculated.Results.With a margin of error of ±3°, success rates were 81.4% for HKA, 92.0% for TPA, and 94.7% for DFA. With the margin of error for alignments extended to ±4°, we obtained a success rate of 92.9% for the HKA, 98.2% for the PTA, and 99.1% for the DFA. The TS showed postoperative results of 2.86 ± 2.02° (mean change 1.76 ± 2.85°).Conclusion.PSCBs for TKA seem to restore the overall leg alignment. Our data suggest that each individual component can be implanted accurately and the results are comparable to the ones in CAS.

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