Is Valgus Cut Angle Based on Radiographic Measurements in Total Knee Arthroplasty Really Inaccurate? A Comparison of Two- and Three-Dimensional Measurements

2021 ◽  
Author(s):  
LiMing Liu ◽  
Kai Lei ◽  
Xin Chen ◽  
HuaQuan Fan ◽  
Liu Yang ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Mechanical Axis ◽  
Three Dimensional ◽  
Anatomical Landmarks ◽  
Radiographic Measurements ◽  
Significant Difference ◽  
Total Knee ◽  
Femoral Mechanical Axis ◽  
Anatomical Axis

AbstractRadiographs are widely used to measure distal femoral valgus cut angle (VCA) in total knee arthroplasty (TKA), but its accuracy is controversial. This study used three-dimensional (3D) reconstruction models to verify the accuracy of VCA measurements on radiographs, and explore the correlation of VCA with hip–knee–ankle (HKA) angle and lateral femoral bowing angle (FBA). A total of 444 osteoarthritis knees of 444 patients from August 2016 to June 2018 was included retrospectively. On radiographs, two-dimensional VCA (VCA-2D) was measured between the femoral mechanical axis and the distal femoral anatomical axis, and HKA was measured between the femoral mechanical axis and the tibial mechanical axis. On the coronal projection of computed tomography 3D models, the anatomical landmarks used for VCA-3D measurements were the same as those on the radiographs, FBA was measured between the proximal and distal femoral anatomical axis. The distributions of VCA-2D and VCA-3D were evaluated by means and variances. The correlation between HKA and VCA and between FBA and VCA was explored. There was a statistical difference between VCA-2D and VCA-3D (p < 0.001), but the deviation was very small (0.15 ± 0.69 degrees), 83.3% of the deviations were less than 1 degree. VCA would increase both in 2D and 3D with increasing of FBA and HKA varus. There was no statistically significant difference between VCA-2D and VCA-3D in patients with moderate varus knees (0–8 degrees of varus) and mild bowing femurs (FBA <5 degrees). Overall, the deviation caused by using radiography to measure VCA was negligible. VCA measurements using radiographs were accurate in patients with moderate varus knees and mildly bowed femurs. This study reflects level of evidence III.

scholarly journals Robotic Arm-Assisted Total Knee Arthroplasty in the Setting of Combined Extra-articular Deformities of the Femur and Tibia

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Sharma Cook-Richardson ◽  
Rasesh Desai
Keyword(s):  
Total Knee Arthroplasty ◽  
Surgical Treatment ◽  
Treatment Option ◽  
Knee Arthroplasty ◽  
Mechanical Axis ◽  
Robotic Arm ◽  
Implant Positioning ◽  
Total Knee ◽  
Anatomical Axis ◽  
Bone Deformities

In this case, we will describe a 68-year-old man with combined femoral and tibial bone deformities who underwent robotic arm-assisted total knee arthroplasty (RATKA) to treat his severe osteoarthritis in the setting of extra-articular deformities that altered the native anatomical axis and the kinematics of the deformed extra-articular bony structures which chronically generated a neomechanical axis. The combination of severe osteoarthritis with extra-articular deformities made the RATKA method the best surgical treatment option taking into account altered kinematics of the native joint which conventional jig-based total knee arthroplasty would not have prioritized during bony cuts and implant positioning. The patient underwent successful knee arthroplasty with robotic arm-assisted technology with restoration of the mechanical axis.

Evaluation and Analysis of the Onlay Patellar Component in Total Knee Arthroplasty

2010 ◽  
Vol 97-101 ◽  
pp. 3773-3776 ◽  
Author(s):  
Chien Wei Liu ◽  
Chia Chi Lo ◽  
Ching Sung Wang ◽  
Chen Tung Yu
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Three Dimensional ◽  
Element Model ◽  
Clinical Results ◽  
Original Design ◽  
Design Modification ◽  
Patellar Component ◽  
Significant Difference ◽  
Total Knee

Complications in total knee arthroplasty (TKA), which may include the inaccuracy of the implantation and the poor component design, can cause major failures in the TKA. Therefore, the present investigation studies the onlay knee implants commonly used clinically to find the major causes of the damage to artificial patella by the computer aided analysis of the three-dimensional finite element model of the artificial patello-femoral joint built through reverse engineering. Results showed that although a significant difference is found in the condition and the state of the stress distribution generated as the patello-femoral joint changes with the flexion of the knees, this variation is still within the tolerable range; but the patellar lateral tilt is something that caught our attention. Furthermore, through the comparison between the study and the clinical results, this investigation concludes that the bone cement on the implant interface is the major cause for the breaking of the pegs, and is not related to the original design of the patella. This study also discovers that slight design modification on the parts of commonly used artificial joints may effectively reduce surgical failure rate; therefore, a more robust design configuration for patellar pegs is proposed.

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 Patient-specific instrumentation improved three-dimensional accuracy in total knee arthroplasty: a comparative radiographic analysis of 1257 total knee arthroplasties

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Leo Pauzenberger ◽  
Martin Munz ◽  
Georg Brandl ◽  
Julia K. Frank ◽  
Philipp R. Heuberer ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Mechanical Axis ◽  
Three Dimensional ◽  
Mobile Bearing ◽  
Patient Specific ◽  
Limb Alignment ◽  
Patient Specific Instrumentation ◽  
Conventional Instrumentation ◽  
Total Knee

Abstract Background The purpose of this study was to compare restoration of mechanical limb alignment and three-dimensional component-positioning between conventional and patient-specific instrumentation in total knee arthroplasty. Methods Radiographic data of patients undergoing mobile-bearing total knee arthroplasty (n = 1257), using either conventional (n = 442) or patient-specific instrumentation (n = 812), were analyzed. To evaluate accuracy of axis restoration and 3D-component-positioning between conventional and patient-specific instrumentation, absolute deviations from the targeted neutral mechanical limb alignment and planned implant positions were determined. Measurements were performed on standardized coronal long-leg and sagittal knee radiographs. CT-scans were evaluated for accuracy of axial femoral implant rotation. Outliers were defined as deviations from the targeted neutral mechanical axis of > ± 3° or from the intraoperative component-positioning goals of > ± 2°. Deviations greater than ± 5° from set targets were considered to be severe outliers. Results Deviations from a neutral mechanical axis (conventional instrumentation: 2.3°± 1.7° vs. patient-specific instrumentation: 1.7°± 1.2°; p < 0.001) and numbers of outliers (conventional instrumentation: 25.8% vs. patient-specific instrumentation: 10.1%; p < 0.001) were significantly lower in the patient-specific instrumentation group. Significantly lower mean deviations and less outliers were detected regarding 3D-component-positioning in the patient-specific instrumentation compared to the conventional instrumentation group (all p < 0.05). Conclusions Patient-specific instrumentation prevented from severe limb malalignment and component-positioning outliers (> ± 5° deviation). Use of patient-specific instrumentation proved to be superior to conventional instrumentation in achieving more accurate limb alignment and 3D-component positioning, particularly regarding femoral component rotation. Furthermore, the use of patient-specific instrumentation successfully prevented severe (> 5° deviation) outliers.

scholarly journals Difference between Mechanical Alignment in Navigation and Scanogram during Total Knee Arthroplasty

2019 ◽  
Vol 2019 ◽  
pp. 1-5 ◽  
Author(s):  
Rohan Bhimani ◽  
Fardeen Bhimani ◽  
Preeti Singh
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Mechanical Axis ◽  
Computer Navigation ◽  
Primary Total Knee Arthroplasty ◽  
P Value ◽  
Mechanical Alignment ◽  
Significant Difference ◽  
Total Knee ◽  
The Mean

Introduction. Malpositioning of the implant results in polyethylene wear and loosing of implant after total knee arthroplasty. Scanogram is often used for measurement of limb alignment. Computer navigation provides real time measurements and thus, the aim is to see any association pre- and postoperatively between coronal alignments measured on scanogram to computer navigation during total knee arthroplasty. Material and Methods. We prospectively gathered data of 200 patients with advanced degenerative symptomatic arthritis, who were consecutively selected for primary total knee arthroplasty with computer navigation. Every patient’s pre- and postoperative scanogram were compared to the intraoperative computer navigation findings. Results. The results show that the preoperative mean mechanical axis on navigation was 10.65° (SD ± 6.95) and on scanogram it was 10.38° (SD ± 6.89). On the other hand, the mean postoperative mechanical axis on navigation was 0.69° (SD ± 0.87) and on scanogram it was 2.73° (SD ± 2.10). Preoperatively, there was no significant difference (p value = 0.46) between the two. However, the postoperative outcomes suggest that there was a noteworthy difference, with no correlation between the mean Hip-Knee Ankle Axis (HKA) and intraoperative mechanical axis (p value <0.0001). Conclusion. Postoperative mechanical alignment values after total knee arthroplasty are lower on navigation than measured on standing full length hip to ankle scanogram.

Static Mediolateral Tilt of the Joint Line after Total Knee Arthroplasty Does Not Reflect Dynamic Tilt during a Stair Ascent Activity

2021 ◽  
Author(s):  
Kazuma Yabu ◽  
Shinichiro Nakamura ◽  
Shinichi Kuriyama ◽  
Kohei Nishitani ◽  
Hiromu Ito ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Weight Bearing ◽  
Three Dimensional ◽  
Joint Line ◽  
Initial Contact ◽  
Stair Ascent ◽  
Radiographic Measurements ◽  
Total Knee ◽  
Matching Techniques

AbstractThe correlation between static and dynamic mediolateral (ML) tilts of the joint line in the coronal plane remains unknown after total knee arthroplasty (TKA). The purpose was to evaluate the ML tilt as measured by two-dimensional to three-dimensional registration during stair ascent in TKA patients, and to examine the correlation between the dynamic ML tilt and radiographic measurements of static indices. Thirty-two knees that underwent TKA using the mechanical alignment method were included. Continuous sagittal fluoroscopy was taken from before initial contact (IC) until after the toe-off (TO) phase during the stair ascent. The ML tilt of the tibial component relative to the ground was analyzed in terms of dynamic alignment using image-matching techniques, whereas static alignment was measured using standing long-leg radiographs. The correlation between static and dynamic ML tilts was evaluated. In the fluoroscopic analysis, the joint line was neutral (0.0 degree, standard deviation [SD] = 3.4 degrees) around IC phases, then was tilted valgus (5.5° valgus, SD = 2.6 degrees) in the mid-stance (MS) phase. After the TO phase, the joint line became almost neutral (0.4 degrees valgus, SD = 3.1 degrees). The dynamic ML tilt was significantly more varus during the IC phase and significantly more valgus in MS and TO phases than the static ML tilt (1.4 degrees valgus, SD = 2.0 degrees). No correlation was found between static and dynamic ML tilts in weight-bearing phases. During stair ascent, the static tilt had no correlation with the dynamic tilt in weight-bearing phases despite being in the same range. Static lower limb alignment does not reflect coronal alignment during motion. Further research should be conducted to determine whether the horizontal dynamic ML tilt can improve long-term durability and clinical outcomes after TKA.

Radiographic Findings in Flexion Instability after Total Knee Arthroplasty

2021 ◽  
Author(s):  
Cole M. Howie ◽  
Simon C. Mears ◽  
C. Lowry Barnes ◽  
Erin M. Mannen ◽  
Jeffrey B. Stambough
Keyword(s):  
Total Knee Arthroplasty ◽  
Soft Tissue ◽  
Knee Arthroplasty ◽  
Revision Surgery ◽  
Tibial Slope ◽  
Joint Line ◽  
Radiographic Findings ◽  
Radiographic Measurements ◽  
Significant Difference ◽  
Total Knee

AbstractFlexion instability (FI) is one of the leading causes of knee pain and revision surgery. Generally, the biomechanical etiology is considered to be a larger flexion than extension gap. This may be due to mismatch of components sizes to the bone or malalignment. Other factors such as muscle weakness may also play a role, and the diagnosis of FI after total knee arthroplasty (TKA) relies on a combination of patient's complaints during stair descent or walking and physical examination findings. Our study examines the role of implant positioning and sizes in the diagnosis of FI. A retrospective review of 20 subjects without perceived FI and 13 patients diagnosed with FI after TKA was conducted. Knee injury and osteoarthritis outcome scores (KOOS) were documented, and postoperative radiographs were examined. Measurements including included tibial slope, condylar offset, femoral joint line elevation along with surrogate soft-tissue measures for girth and were compared between groups. The FI group was found to have a significantly lower KOOS score compared with the non-FI group (55.6 vs. 73.5; p = 0.009) as well as smaller soft-tissue measurements over the pretubercle region (6.0 mm vs. 10.6 mm; p = 0.007). Tibial slope, condylar offset ratios, and femoral joint line elevation were not significantly different between the FI and non-FI groups. We noted a significant difference in tibial slope in posterior-stabilized implants in subjects with and without FI (6.4° vs. 1.5°; p = 0.003). Radiographic measurements consistent with malalignment were not indicative of FI. X-ray measurements alone are not sufficient to conclude FI as patient symptoms, and clinical examinations remain the key indicators for diagnosis. Radiographic findings may aid in surgeon determination of an underlying cause for an already identified FI situation and help in planning revision surgery.

scholarly journals Is Robotic TKA Having Added Advantage over Conventional TKA? A Comparative Study of Functional and Radiological Outcome of Robotic versus Conventional Total Knee Arthroplasty

2021 ◽  
Author(s):  
Himanshu Panchal ◽  
Ashwini S. Patel
Keyword(s):  
Total Knee Arthroplasty ◽  
Soft Tissue ◽  
Knee Arthroplasty ◽  
Functional Outcomes ◽  
Mechanical Axis ◽  
Statistical Significance ◽  
Radiological Outcome ◽  
Soft Tissue Management ◽  
Significant Difference ◽  
Total Knee

Abstract Objective Total knee arthroplasty (TKA) is most commonly performed procedure in patients who are not showing improvement in pain, activities of daily living, and quality of life by conservative modalities. Precise component implantation and soft tissue management is required to achieve desired outcome following TKA. 1.3% patients remain disappointed due to persistent pain, 24% due to instability, and 2.5% due to malalignment following TKA. Robotic TKA is associated with the use of customized implants and bone cuts leading to precise component implantation and reduced deviation from mechanical axis in coronal, transverse, and sagittal plane and proper soft tissue management. This study compares conventional against robotic TKA in terms of clinical, functional, and radiological outcome. Materials and Methods  This is a prospective randomized control trial carried over period of 3 years where patients were selected on the basis of inclusion and exclusion criteria and were randomly divided into both groups and compared using their pre- and postoperative radiological and functional outcomes as well as intraoperative and postoperative complications and statistical significance of difference was calculated. Results There was no significant difference in terms of ROM, KOOS (Knee Injury and Osteoarthritis Outcome Score), (Knee Society Score) KSS, Eq. 5D, (Western Ontario and McMaster Universities Osteoarthritis Index) WOMAC, and (visual analog scale) VAS scores while we found significant difference in mechanical axis deviation, femoral and tibial implant alignment in both planes. Discussion Advantages of using robotic TKA are customized preoperative planning, implants, cuts, accuracy of the intraoperative procedure, and radiological superiority with no significant differences in clinical and functional outcomes. In fact, robotic TKA is associated with steep learning curve, increased cost, and operative time. Still there are no added complications caused by it.

Does Kinematic Alignment Improve Short-Term Functional Outcomes after Total Knee Arthroplasty Compared with Mechanical Alignment? A Systematic Review and Meta-analysis

2017 ◽  
Vol 31 (01) ◽  
pp. 078-086 ◽  
Author(s):  
Yanhong Li ◽  
Yuliang Wang ◽  
Mingxuan Yang ◽  
Shuanke Wang
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Functional Outcomes ◽  
Mechanical Axis ◽  
Meta Analysis ◽  
Mechanical Alignment ◽  
Short Term ◽  
Significant Difference ◽  
Total Knee

AbstractThis meta-analysis was conducted to study whether kinematically aligned total knee arthroplasty (TKA) improves short-term functional outcomes compared with mechanical alignment without changing the hip–knee–ankle angle. Prospective cohort studies were searched from electronic literature databases, including PubMed, Web of Science, Embase (Ovid interface), and Cochrane Library (Ovid interface). Total 1,159 records were identified. Six trials involving 561 patients were eligible for data extraction and meta-analysis. The included studies recorded outcomes in the follow-up range from 6 to 34 months. Primary outcomes were to assess the functional outcomes in follow-up, and KA group achieved better performance on WOMAC score (mean difference [MD] = −18.82, 95% CI: −16.06 to −5.58), knee function score (MD = 7.23, 95% CI: 0.52–13.94), Oxford knee score (MD = 4.76, 95% CI: 0.40–9.12), and knee range of flexion (MD = 4.48, 95% CI: 2.09–6.86), whereas other parameters including Knee Society score, knee range of extension, VAS pain score, and the occurrence of the complications were without significant difference (p > 0.05). Second outcomes evaluated the perioperative clinic indexes. Our meta-analysis showed that KA group had a shorter time of operation (MD = −15.44, 95% CI: −27.47 to −3.71) and a longer walk distance before discharge (MD = 53.24, 95% CI: 21.32–85.15) when compared with the MA group, whereas the change in hemoglobin, incision length, knee range of flexion before discharge, and length of stays were without significant difference (p > 0.05). Third outcomes were used to analyze the alignment data. Our study showed that KA had larger angles of femoral component and mechanical axis of the femur (MD = −1.95,95% CI: −2.77 to −1.13), tibial component and mechanical axis of tibia (MD = 2.06, 95% CI: 1.43–2.70), anatomic knee angle (MD = −0.72, 95% CI: −1.33 to −0.11), and operative limb alignment (MD = −1.97, 95% CI: −2.50 to −1.45,) compared with the MA group, but the hip–knee–ankle angles between the two groups were similar. KA provided better functional outcomes and better flexion following short-term follow-up of TKA. However, longer-term follow-up and larger sample studies are needed to put into research in the future.

Low-Degree Tibial Slope Angle Prevents Component Overhang by Enlarging the Lateral Plateau Surface Area in Total Knee Arthroplasty

2020 ◽  
Author(s):  
Mehmet Emin Simsek ◽  
Mustafa Akkaya ◽  
Safa Gursoy ◽  
Özgür Kaya ◽  
Murat Bozkurt
Keyword(s):  
Total Knee Arthroplasty ◽  
Surface Area ◽  
Knee Arthroplasty ◽  
Tibial Plateau ◽  
Slope Angle ◽  
Three Dimensional ◽  
Tibial Slope ◽  
Total Knee ◽  
Lateral Plateau ◽  
Gender Groups

AbstractThis study aimed to investigate whether overhang or underhang around the tibial component that occurs during the placement of tibial baseplates was affected by different slope angles of the tibial plateau and determine the changes in the lateral and medial plateau diameters while changing the slope angle in total knee arthroplasty. Three-dimensional tibia models were reconstructed using the computed tomography scans of 120 tibial dry bones. Tibial plateau slope cuts were performed with 9, 7, 5, 3, and 0 degrees of slope angles 2-mm below the subchondral bone in the deepest point of the medial plateau. Total, lateral, and medial tibial plateau areas and overhang/underhang rates were measured at each cut level. Digital implantations of the asymmetric and symmetric tibial baseplates were made on the tibial plateau with each slope angles. Following the implantations, the slope angle that prevents overhang or underhang at the bone border and the slope angle that has more surface area was identified. A significant increase was noted in the total tibial surface area, lateral plateau surface area, and lateral anteroposterior distance, whereas the slope cut angles were changed from 9 to 0 degrees in both gender groups. It was found that the amount of posteromedial underhang and posterolateral overhang increased in both the asymmetric and symmetric tibial baseplates when the slope angle was changed from 0 to 9 degrees. Although the mediolateral diameter did not change after the proximal tibia cuts at different slope angles, the surface area and anteroposterior diameter of the lateral plateau could change, leading to increased lateral plateau area. Although prosthesis designs are highly compatible with the tibial surface area, it should be noted that the component overhangs, especially beyond the posterolateral edge, it can be prevented by changing the slope cut angle in males and females.

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