scholarly journals Comparison of post-operative three-dimensional and two-dimensional evaluation of component position for total knee arthroplasty

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Osamu Tanifuji ◽  
Tomoharu Mochizuki ◽  
Hiroshi Yamagiwa ◽  
Takashi Sato ◽  
Satoshi Watanabe ◽  
...  
Keyword(s):  
Tibial Component ◽  
Sagittal Alignment ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Component Position ◽  
Operative Planning ◽  
Operative Evaluation ◽  
Total Knee ◽  
The Difference ◽  
3D Evaluation

Abstract Purpose The purpose of this study was to evaluate the post-operative three-dimensional (3D) femoral and tibial component positions in total knee arthroplasty (TKA) by the same co-ordinates’ system as for pre-operative planning and to compare it with a two-dimensional (2D) evaluation. Materials and methods Sixty-five primary TKAs due to osteoarthritis were included. A computed tomography (CT) scan of the femur and tibia was obtained and pre-operative 3D planning was performed. Then, 3D and 2D post-operative evaluations of the component positions were performed. KneeCAS (LEXI, Inc., Tokyo, Japan), a lower-extremity alignment assessment system, was used for the 3D post-operative evaluation. Standard short-knee radiographs were used for the 2D post-operative evaluation. Differences between the pre-operative planning and post-operative coronal and sagittal alignment of components were investigated and compared with the results of the 3D and 2D evaluations. Results According to the 3D evaluation, the difference between the pre-operative planning and actual post-operative sagittal alignment of the femoral component and the coronal and sagittal alignments of the tibial component were 2.6° ± 1.8°, 2.2° ± 1.8° and 3.2° ± 2.4°, respectively. Using the 2D evaluation, they were 1.9° ± 1.5°, 1.3° ± 1.2° and 1.8° ± 1.4°, making the difference in 3D evaluation significantly higher (p = 0.013, = 0.003 and < 0.001). For the sagittal alignment of the femoral component and the coronal and sagittal alignment of the tibial component, the outlier (> ± 3°) ratio for the 3D evaluation was also significantly higher than that of the 2D evaluation (p < 0.001, = 0.009 and < 0.001). Conclusions The difference between the pre-operative planning and post-operative component alignment in the 3D evaluation is significantly higher than that of the 2D, even if the same cases have been evaluated. Two-dimensional evaluation may mask or underestimate the post-operative implant malposition. Three-dimensional evaluation using the same co-ordinates’ system as for pre-operative planning is necessary to accurately evaluate the post-operative component position.

scholarly journals Improved Component Placement Accuracy with Robotic-Arm Assisted Total Knee Arthroplasty

2020 ◽  
Author(s):  
Ormonde Mahoney ◽  
Tracey Kinsey ◽  
Nipun Sodhi ◽  
Michael A. Mont ◽  
Antonia F. Chen ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Tibial Component ◽  
Three Dimensional ◽  
Dimensional Accuracy ◽  
Robotic Arm ◽  
Component Position ◽  
Absolute Deviation ◽  
Total Knee ◽  
Study Center

AbstractComponent position of total knee arthroplasty (TKA) has been shown to influence prosthetic survivorships and clinical outcomes. Our objective was to compare the three-dimensional accuracy to plan of robotic-arm assisted TKA (RATKA) with conventional TKA for component position. We conducted a nonrandomized, prospective study comparing 143 RATKA with 86 conventional TKA operated at four U.S. centers between July 2016 and October 2018. Computed tomography (CT) scans obtained approximately 6 weeks postoperatively were analyzed using anatomical landmarks. Absolute deviation from surgical plans were defined as the absolute value of the difference between the CT measurements and surgeons' femoral and tibial component mechanical varus/valgus alignment, tibial component posterior slope, and femoral component internal/external rotation. Differences of absolute deviations were tested using stratified Wilcoxon's tests that controlled for study center. Patient-reported outcome measures collected through 1 postoperative year were modeled using multiple regression controlling for age, sex, body mass index, study center, and the preoperative score. RATKA demonstrated greater accuracy for tibial component alignment (median [25th, 75th percentiles] absolute deviation from plan of all centers combined for conventional vs. RA, 1.7 [0.9, 2.9] vs. 0.9 [0.4, 1.9] degrees, p < 0.001), femoral component rotation (1.5 [0.9, 2.5] vs. 1.3 [0.6, 2.5] degrees, p = 0.015), and tibial slope (2.9 [1.5, 5.0] vs. 1.1 [0.6, 2.0] degrees, p < 0.001). In multivariable analyses, RATKA showed significantly greater Veterans RAND 12-item health survey (VR-12) physical component scores (adjusted mean difference [95% confidence interval (CI)]: 2.4 [0.2, 4.5] points, p = 0.034) and qualitatively greater Knee Society (KS) composite functional scores (3.5 [−1.3, 8.2] points, p = 0.159), though not statistically significant. Compared with conventional instrumentation, RATKA demonstrated greater three-dimensional accuracy to plan for various component positioning parameters and clinical improvements in physical status and function with no major safety concerns during the first postoperative year. These results may be attributed to the preoperative CT scan planning, real-time intraoperative feedback, and stereotactic-guided cutting that takes into consideration patient-specific bony anatomy. These findings support the use of RATKA for enhanced arthroplasty outcomes.

Preoperative CT-Based Three-Dimensional Templating in Robot-Assisted Total Knee Arthroplasty More Accurately Predicts Implant Sizes than Two-Dimensional Templating

2018 ◽  
Vol 32 (07) ◽  
pp. 642-648 ◽  
Author(s):  
J. R. T. Pietrzak ◽  
F. E. Rowan ◽  
B. Kayani ◽  
M. J. Donaldson ◽  
S. S. Huq ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Tibial Component ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Robot Assisted ◽  
Ct Guided ◽  
Digital Templating ◽  
Preoperative Ct ◽  
Total Knee

AbstractPatient dissatisfaction after total knee arthroplasty (TKA) is a concern. Surgical error is a common, avoidable cause of failed TKA. Correct femoral and tibial component sizing improves implant longevity, clinical outcomes, knee balance, and pain scores. We hypothesized that preoperative three-dimensional (3D) templating for robot-assisted TKA (RA-TKA) is more accurate than two-dimensional (2D) digital templating. Prospectively collected data from 31 RA-TKAs were assessed to determine accuracy pertaining to implant sizing and positioning. All cases undergoing RA-TKA undergo preoperative CT-scans as per protocol. Three blinded observers retrospectively templated these knees for TKA using standard radiographs. We compared whether 2D templating was as accurate as CT-guided templating. Postoperative radiographs were then evaluated for sizing and positioning. Intraclass correlation coefficients (ICCs) and the effect of learning curve were assessed. Preoperative femoral component 3D templating and retrospective blinded 2D templating accuracies were 96.6% and 52.9%, respectively (χ 2: 17.965; odds ratio [OR]: 24.957, 3.250–191.661; p < 0.001). Tibial component 3D and 2D templating accuracies were 93.1% and 28.7%, respectively (χ 2: 36.436; OR: 33.480, 7.400–151.481; p < 0.001). ICC for the three radiograph observers was 0.920 (95% confidence interval [CI]: 0.652–0.890; p < 0.001) for the femur and 0.833 (0.717–0.911; p < 0.001) for the tibia, showing excellent agreement. We conclude that preoperative CT-based templating for RA-TKA more accurately predicts the size of implants compared with traditional 2D digital templating. This may improve operating room efficiency and cost containment.

Theory of ultrasonic attenuation in one and two dimensional metals

1976 ◽  
Vol 54 (14) ◽  
pp. 1454-1460 ◽  
Author(s):  
T. Tiedje ◽  
R. R. Haering
Keyword(s):  
Ultrasonic Attenuation ◽  
Three Dimensional ◽  
Electronic Systems ◽  
Two Dimensional ◽  
Temperature Dependent ◽  
One Dimensional ◽  
The Difference

The theory of ultrasonic attenuation in metals is extended so that it applies to quasi one and two dimensional electronic systems. It is shown that the attenuation in such systems differs significantly from the well-known results for three dimensional systems. The difference is particularly marked for one dimensional systems, for which the attenuation is shown to be strongly temperature dependent.

Midterm Comparison of Tibial Fixation between Posterior Cruciate-Retaining and Substituting Porous Tantalum Total Knee Arthroplasty: Three-Dimensional Computed Tomography Analysis

2019 ◽  
Vol 34 (01) ◽  
pp. 047-056
Author(s):  
Takao Kaneko ◽  
Norihiko Kono ◽  
Yuta Mochizuki ◽  
Masaru Hada ◽  
Shinya Toyoda ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Total Knee Arthroplasty ◽  
Bone Quality ◽  
Knee Arthroplasty ◽  
Tibial Component ◽  
Three Dimensional ◽  
Porous Tantalum ◽  
Cruciate Retaining ◽  
Significant Difference ◽  
Total Knee

AbstractPorous tantalum tibial component is durable with excellent bone ingrowth, higher knee scores, and long-term survivorship. However, to our knowledge, the effect of posterior cruciate-retaining (CR) and posterior cruciate-substituting (PS) porous tantalum tibial component has not been reported. The aim of the current study was to investigate the prosthetic bone quality between CR porous tantalum tibial component and PS using three-dimensional multi-detector-row computed tomography (3D-MDCT). Porous twenty-two (22) CR total knee arthroplasties and 22 PS received 3D-MDCT at every 6 months up to 5.5 years postoperatively to assess prosthetic bone quality (bone marrow contents/tissue volumes [BMC/TV, mg/cm3]) underneath the pegs of porous tantalum modular tibial component. Clinical outcomes (Knee Society score [KSS], Western Ontario and McMaster Universities (WOMAC), FJS-12, Patella score) were evaluated at a minimum follow-up period of 5.5 years. No statistically significant differences were found in age, gender, body mass index, KSS, and BMC/TV volumes in the proximal tibia between the two groups before total knee arthroplasty (TKA). There were also no significant differences between the CR and PS groups with regard to BMC/TV at every 6 months up to 5.5 years after TKA. At 5.5 years postoperatively, there was no significant difference between the two groups in terms of the KSS, WOMAC, forgotten joint score (FJS-12), and Patella score. The present study revealed that the prosthetic bone quality of the CR porous tantalum tibial component and PS were equivalent at every 6 months up to 5.5 years after TKA. This study reflects level II evidence.

scholarly journals Numerical and Experimental Study of Topographic Speed-Up Effects in Complex Terrain

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3896 ◽  
Author(s):  
Takanori Uchida ◽  
Kenichiro Sugitani
Keyword(s):  
Wind Tunnel ◽  
Complex Terrain ◽  
Three Dimensional ◽  
Wind Tunnel Experiment ◽  
Dimensional Structure ◽  
Spanwise Direction ◽  
Two Dimensional ◽  
Wind Tunnel Experiments ◽  
Wire Probe ◽  
The Difference

Our research group is developing computational fluid dynamics (CFD)-based software for wind resource and energy production assessments in complex terrain called RIAM-COMPACT (Research Institute for Applied Mechanics, Kyushu University (RIAM)-Computational Prediction of Airflow over Complex Terrain), based on large eddy simulation (LES). In order to verify the prediction accuracy of RIAM-COMPACT, we conduct a wind tunnel experiment that uses a two-dimensional steep ridge model with a smooth surface. In the wind tunnel experiments, airflow measurements are performed using an I-type hot-wire probe and a split film probe that can detect forward and reverse flows. The results of the numerical simulation by LES are in better agreement with the wind tunnel experiment using the split film probe than the results of the wind tunnel experiment using the I-type hot wire probe. Furthermore, we calculate that the two-dimensional ridge model by changing the length in the spanwise direction, and discussed the instantaneous flow field and the time-averaged flow field for the three-dimensional structure of the flow behind the model. It was shown that the eddies in the downwind flow-separated region formed behind the two-dimensional ridge model were almost the same size in all cases, regardless of the difference in the length in the spanwise direction. In this study, we also perform a calculation with a varying inflow shear at the inflow boundary. It was clear that the size in the vortex region behind the model was almost the same in all the calculation results, regardless of the difference in the inflow shear. Next, we conduct wind tunnel experiments on complex terrain. In the wind tunnel experiments using a 1/2800 scale model, the effect of artificial irregularities on the terrain surface did not significantly appear on the airflow at the hub height of the wind turbine. On the other hand, in order to investigate the three-dimensional structure of the airflow in the swept area in detail, it was clearly shown that LES using a high-resolution computational grid is very effective.

The Sahara

2017 ◽  
Author(s):  
Barbara E. Barich
Keyword(s):  
Human Body ◽  
Manufacturing Process ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Dimensional Representation ◽  
Three Dimensional Representation ◽  
The Difference ◽  
Symbolic Content ◽  
The Relationship

This chapter discusses the collection of objects, in clay and stone, from various pastoral Saharan sites whose original core area lay between Libya (Tadrart Acacus) and Algeria (Tassili- n-Ajjer). The chapter starts from the general theme of the relationship between the figurines and the subjects they represent, and the difference between two-dimensional and three-dimensional representation. It goes on to discuss the manufacturing process of the clay specimens (dating from between 7000 and 4000 years ago) and the significance of the changes introduced by the Neolithic. Most of the items studied fall into the category of zoomorphic figurines, with only two anthropomorphic examples, and find in the depiction of cattle their most striking subject. These representations possess an evident symbolic content which must be framed within the pastoral ideology of the Saharan Neolithic. In the anthropomorphic figurines the representation of the human body also plays the role of recapturing the sense of wholeness.

Accuracy assessment of surgical planning and three-dimensional-printed patient-specific guides for orthopaedic osteotomies

2017 ◽  
Vol 231 (6) ◽  
pp. 499-508 ◽  
Author(s):  
Gwen Sys ◽  
Hannelore Eykens ◽  
Gerlinde Lenaerts ◽  
Felix Shumelinsky ◽  
Cedric Robbrecht ◽  
...  
Keyword(s):  
Accuracy Assessment ◽  
Average Distance ◽  
Three Dimensional ◽  
Patient Specific ◽  
Second Phase ◽  
Experimental Setup ◽  
Operative Planning ◽  
The Difference ◽  
Two Phases ◽  
Improved Accuracy

This study analyses the accuracy of three-dimensional pre-operative planning and patient-specific guides for orthopaedic osteotomies. To this end, patient-specific guides were compared to the classical freehand method in an experimental setup with saw bones in two phases. In the first phase, the effect of guide design and oscillating versus reciprocating saws was analysed. The difference between target and performed cuts was quantified by the average distance deviation and average angular deviations in the sagittal and coronal planes for the different osteotomies. The results indicated that for one model osteotomy, the use of guides resulted in a more accurate cut when compared to the freehand technique. Reciprocating saws and slot guides improved accuracy in all planes, while oscillating saws and open guides lead to larger deviations from the planned cut. In the second phase, the accuracy of transfer of the planning to the surgical field with slot guides and a reciprocating saw was assessed and compared to the classical planning and freehand cutting method. The pre-operative plan was transferred with high accuracy. Three-dimensional-printed patient-specific guides improve the accuracy of osteotomies and bony resections in an experimental setup compared to conventional freehand methods. The improved accuracy is related to (1) a detailed and qualitative pre-operative plan and (2) an accurate transfer of the planning to the operation room with patient-specific guides by an accurate guidance of the surgical tools to perform the desired cuts.

scholarly journals Radiographic evaluation of tibial component alignment in total knee arthroplasty following extramedullary and intramedullary tibial referencing

2017 ◽  
Vol 3 (6) ◽  
pp. 1199
Author(s):  
B. Harikrishnan ◽  
Anjan Prabhakara ◽  
Gururaj R. Joshi
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Tibial Component ◽  
Radiographic Evaluation ◽  
Component Alignment ◽  
Tibial Component Alignment ◽  
Knee Deformity ◽  
Total Knee ◽  
The Difference

<p class="abstract"><strong>Background:</strong> Long term survivorship of total knee arthroplasty (TKA) is significantly dependant on prostheses alignment. The debate on optimal referencing for femoral component is largely resolved with Intra-medullary jigs reproducing superior alignment. However there is still a contention about whether intramedullary or extramedullary jigs are better for tibial referencing. This study aims to compare the accuracy of tibial component alignment in TKA using intramedullary and extramedullary tibial referencing jigs.</p><p class="abstract"><strong>Methods:</strong> Between December 2012 and September 2014, 66 primary conventional cemented TKAs were performed using Nexgen-LPS Flex (Zimmer) implants in 55 patients, 50-80 y old (mean 65.54 y) with osteoarthritis/rheumatoid arthritis. Intramedullary and extramedullary tibial referencing was used in alternate patients undergoing TKA after excluding patients with BMI <span style="text-decoration: underline;">&gt;</span>35 kg/m<sup>2</sup>, knee deformity <span style="text-decoration: underline;">&gt;</span>15<sup>0</sup>,excessive tibial bowing, previous fractures/surgeries/retained metalwork around knee. Postoperatively, tibial component alignment (TCA) in coronal plane was assessed using AP radiograph of leg. A 3<sup>º</sup> cutoff from neutral mechanical axis (i.e., 90<sup>o</sup>±3<sup>o</sup>) was considered acceptable.<strong></strong></p><p class="abstract"><strong>Results:</strong> The intramedullary group (n=33) had 4 outliers (TCA &gt;93<sup>º</sup> or &lt;87<sup>º</sup>) whereas the extramedullary group (n=33) had 7 outliers (p=0.511). The difference in mean TCA between intramedullary and extramedullary groups was not statistically significant [90.70±2.43 and 90.55±2.17 (p=0.790)]. There were no significant per-operative/post-operative complications in either group.</p><p><strong>Conclusions:</strong> We conclude that both intramedullary and extramedullary tibial referencing guides can be used to achieve desired tibial component alignment (90±3<sup>º</sup>) in TKA. However the surgeon should appreciate the benefits and deficiencies of either types of tibial referencing and use whichever is suited in a particular case. </p>

Accuracy of Bone Resection in MAKO Total Knee Robotic-Assisted Surgery

2019 ◽  
Author(s):  
James D. Sires ◽  
Johnathan D. Craik ◽  
Christopher J. Wilson
Keyword(s):  
Polyethylene Wear ◽  
Three Dimensional ◽  
Revision Arthroplasty ◽  
Absolute Difference ◽  
Future Research ◽  
Coronal Alignment ◽  
Bone Resection ◽  
Total Knee ◽  
The Difference ◽  
Preoperative Plan

AbstractAccurate component positioning and planning is vital to prevent malalignment of total knee arthroplasty (TKA) as malalignment is associated with an increased rate of polyethylene wear and revision arthroplasty. The MAKO total knee robotic arm-assisted surgery (Stryker, Kalamazoo, MI) uses a preoperative computed tomography scan of the patient's knee and three-dimensional planning to size and orientate implants prior to bone resection. The aim of this study was to determine the accuracy of the MAKO Total Knee system in achieving the preoperative plan for bone resection and final limb coronal alignment. A series of 45 consecutive cases was performed using the MAKO Total Knee system and Triathlon Total Knee implant (Stryker) between April 2018 and May 2019. The difference between what was planned and what was achieved for bone resection and coronal limb alignment was calculated. A total of 37 patients had their data captured using the MAKO system software. Mean difference from the plan for distal femoral cuts was 0.38mm (0.32) deep/proud, anterior femoral cuts 0.44mm (0.27) deep/proud and tibial cuts 0.37mm (0.30) deep/proud. In total, 99 out of 105 (94.29%) of bone resections were within 1mm of the plan. Mean absolute difference in final limb coronal alignment was 0.78° (0.78), with 78.13% being ≤1.00° of the plan, and 100% being ≤3.00° of the plan. The accuracy in achieving preoperatively planned bone resection and final limb coronal alignment using the MAKO Total Knee system is high. Future research is planned to look at whether this is associated with decreased rates of polyethylene wear and revision arthroplasty.

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