Preoperative planning of total knee arthroplasty: reliability of axial alignment using a three-dimensional planning approach

2021 ◽  
pp. 028418512110290
Author(s):  
Stefan Tiefenboeck ◽  
Stefan Sesselmann ◽  
Dominic Taylor ◽  
Raimund Forst ◽  
Frank Seehaus
Keyword(s):  
Preoperative Planning ◽  
Three Dimensional ◽  
Posterior Condylar Axis ◽  
Observer Reliability ◽  
Epicondylar Axis ◽  
Inter Observer Variability ◽  
Clinical Epicondylar Axis ◽  
Posterior Condylar ◽  
Total Knee ◽  
Axial Ct

Background Preoperative templating of total knee arthroplasty (TKA) can nowadays be performed three-dimensionally with software solutions using computed tomography (CT) datasets. Currently there is no consensus concerning the axial orientation of TKA components in three-dimensional (3D) planning. Purpose To assess intra-/inter-observer reliability of detection of different bony landmarks in planning axial component alignment using axial CT images and 3D reconstructions. Material and Methods Intra- and inter-observer reliability of determination of four predefined axial femoral and tibial axes was calculated using data from CT scans. Axes determination was performed on the axial slices and on the 3D reconstruction using preoperative planning software. In summary, 61 datasets were analyzed by one medical student (intra-observer reliability) and 15 datasets were analyzed by four different observers independently (inter-observer reliability). Results For the femur, clinical epicondylar axis and posterior condylar axis showed the best reliability with an inter-observer variability of 0.7° and 0.5°, respectively. For the tibia, posterior condylar axis provided best reliability (inter-observer variability: 1.7°). Overall variability was greater for tibial than for femoral axes. Reliability of axis determination was more accurate using axial CT slices rather than 3D reconstructions. Conclusion The femoral clinical epicondylar axis is highly reliable. Landmarks for the tibia are not as easily identifiable as for the femur. The tibial posterior condylar axis presents the axis with highest reliability. Based on these results, clinical epicondylar axis for orientation of the femoral TKA component and posterior condylar axis for the tibial implant, both defined on axial slices can be recommended.

Incidence of Femoral Component Malrotation Using Posterior Condylar Referencing in Total Knee Arthroplasty

2019 ◽  
Vol 33 (10) ◽  
pp. 971-977
Author(s):  
Diana K. Lee ◽  
Matthew J. Grosso ◽  
David P. Trofa ◽  
Julian J. Sonnenfeld ◽  
H. John Cooper ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Femoral Component ◽  
Knee Arthroplasty ◽  
External Rotation ◽  
Prognostic Impact ◽  
Posterior Condylar Axis ◽  
Femoral Component Rotation ◽  
Component Rotation ◽  
Posterior Condylar ◽  
Total Knee

AbstractProper femoral component rotation in total knee arthroplasty (TKA) is important, given the prognostic impact of a poorly positioned component. The purpose of this observational study was to determine the incidence of femoral component malrotation using posterior condylar axis (PCA) referencing. A total of 100 knees in 92 patients with varus gonarthritis of the knee undergoing primary TKA using a standard medial parapatellar approach were evaluated intraoperatively. After distal femoral resection, the standard femoral sizing guide referencing the posterior condylar axis was used to set femoral component rotation. This was then compared with both the transepicondylar (TEA) and trochlear anteroposterior axes (TRAx). Disparites were recorded and corrected in line with the epicondylar axis. Rotational adjustment for addition of further external rotation was made in 13 (13.0%) cases. In seven cases, the medial pin sites were raised between 1 and 3 mm, and in six cases, the lateral pin site was lowered between 1 and 3 mm (based on risk of notching the femoral cortex). It is critical to not rely exclusively on the PCA to confirm rotational positioning of the femoral component as predicted by posterior condylar referencing guides. Intraoperative adjustment and confirmation using the TEA and TRAx occurred in 13% of primary TKA cases, which might have, otherwise, had a significant effect on the clinical outcome.

Anatomic Rotational Relationship of Distal Femur in Indian Population and its Implication in Total Knee Arthroplasty: A Magnetic Resonance Imaging Based Study

2021 ◽  
Author(s):  
Balgovind S Raja ◽  
Kshitij Gupta ◽  
Sukhmin Singh ◽  
Abdusamad V ◽  
Hawaibam Nongdamba ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Magnetic Resonance ◽  
Indian Population ◽  
Distal Femur ◽  
External Rotation ◽  
Bony Landmarks ◽  
Clinical Epicondylar Axis ◽  
Posterior Condylar ◽  
Total Knee ◽  
Relationship Of

Abstract Background Bony landmarks for referencing distal femoral rotation may differ with ethnic populations. The study aims to find out the relationship of the bony landmarks of distal femur for rotational alignment of femoral component in total knee arthroplasty in Indian population and compare it with other ethnic groups. Methods Rotational relationship of distal femoral bony landmarks was studied using magnetic resonance images of 141 knees. The condylar twist angle (CTA), Whiteside's-posterior condylar axis angle (WL/PCL), Whiteside's-anatomical epicondylar angle (WL/A-EA) and difference between the two epicondylar axes (S-EA/A-EA) were measured. The effect of gender, side and age of these relationships was analyzed. Results The mean CTA, WL/A-EA/WL/PCL and A-EA/S-EA was found to be 5.59 ± 2°, 89.38 ± 2.66°, 5.44 ± 2.88°, 3.11 ± 0.54° respectively. A-EA/S-EA was found to be lower in younger population as compared to the older population. Rest none of the variables showed any significant difference when compared against age, sex or side. Conclusion The posterior condylar axis was 5.59˚ externally rotated in relation to clinical epicondylar axis. About 2.5° of added external rotation is required in jigs using the conventional 3° of inbuilt external rotation, if clinical epicondylar axis is taken as reference for apt placement of the femoral component.

scholarly journals Intra- and inter‐observer reliability of implant positioning evaluation on a CT-based three‐dimensional postoperative matching system for total knee arthroplasty

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Shotaro Watanabe ◽  
Ryuichiro Akagi ◽  
Yuki Shiko ◽  
Yoshimasa Ono ◽  
Yohei Kawasaki ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Image Matching ◽  
Mechanical Axis ◽  
Three Dimensional ◽  
Reference Points ◽  
Ct Image ◽  
Implant Position ◽  
Observer Reliability ◽  
Total Knee ◽  
Implant Alignment

Abstract Background The evaluation of postoperative total knee arthroplasty (TKA) alignment mainly relies on measurement data obtained from plain radiographs. The aim of this retrospective observational study was to document the intra- and inter-observer reliability in assessment of TKA component positioning after surgery using a three-dimensional (3D) computed tomography (CT) image matching system. Methods Fourteen knees from 14 patients who received primary TKA were included, and images were analyzed by blinded readers not associated with the surgeries. The examiner digitized the reference points according to defined landmarks, and the designated size component was superimposed to the 3D reconstructed CT model for measurement. In addition to the evaluation of implant position against the coronal and sagittal lower limb mechanical axes that were defined based on bony landmarks, implant position against axes connecting implant-based reference points that are easier to indicate was evaluated. Results The overall intra- and inter-observer reliabilities determined by the intraclass correlation coefficients (ICC) of the implant alignment measurement for both femoral and tibial components were good (ICC > 0.60), except in the direction of femoral flexion and extension, for both mechanical and implant-based axes. The difference between implant alignment measurements according to the traditional mechanical axis and the implant-based axis ranged between means of 0.08o and 1.70o and were statistically significantly different. Conclusions The postoperative evaluation of implant position in the coronal and sagittal planes using 3D-CT image matching is reliable and has good reproducibility except for the sagittal alignment assessment of the femoral component. The measured implant position according to the traditional mechanical axis and the implant-based axis were slightly but significantly different.

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