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

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.


Author(s):  
M Swank ◽  
J R Romanowski ◽  
L L Korbee ◽  
S Bignozzi

Total knee arthroplasty (TKA) remains one of the most successful procedures in orthopaedic surgery. Complications certainly exist and are often related to failure of knee ligament balance. This asymmetry subsequently leads to component mal-alignment and loosening often secondary to deviation of the lower extremity mechanical axis. Understanding knee mechanics is essential, and recent technological advances have begun to minimize postoperative problems. A tensioning device that respects the native patellofemoral anatomy as well as the natural ligamentous strains has been developed. The surgical integration of computer-assisted navigation has allowed for enhanced accuracy and subsequently better results. The purpose of the current paper is to discuss the evolution of an improved ligament tensioning device, in the setting of classic mechanical guidance versus computer assistance and its postoperative impact on total knee outcomes in terms of manipulation rates and two-year radiographic alignment data. Based on a single surgeon series, mechanically guided arthroplasties resulted in a 16 per cent manipulation rate. Computer assistance with spacer blocks decreased the manipulation rate to 14 per cent, while using a novel tensioner device further decreased the manipulation rate to 7 per cent, a significant difference of p <0.01. Radiographic data illustrate all TKAs with the tensioner to be within 4° of the desired position.



2019 ◽  
Vol 34 (01) ◽  
pp. 047-056
Author(s):  
Takao Kaneko ◽  
Norihiko Kono ◽  
Yuta Mochizuki ◽  
Masaru Hada ◽  
Shinya Toyoda ◽  
...  

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.





2014 ◽  
Vol 32 (5) ◽  
pp. 619-626 ◽  
Author(s):  
Masami Ishimaru ◽  
Yoshitaka Shiraishi ◽  
Satoru Ikebe ◽  
Hidehiko Higaki ◽  
Kazunori Hino ◽  
...  


Author(s):  
Shuhei Hiyama ◽  
Tsuneari Takahashi ◽  
Katsushi Takeshita

AbstractKinematically aligned total knee arthroplasty (KATKA) was developed to improve the anatomical alignment of knee prostheses, assisting in restoring the native alignment of the knee and promoting physiological kinematics. Early clinical results were encouraging, showing better functional outcomes than with mechanically aligned total knee arthroplasty (MATKA). However, there have been concerns about implant survival, and follow-up at 10 years or more has not been reported. In addition, randomized controlled trials (RCTs) comparing KATKA with MATKA have reported inconsistent results. The current meta-analysis of RCTs with a minimum of 2 years of follow-up investigated the clinical and radiological differences between KATKA and MATKA. A systematic review of the English language literature resulted in the inclusion of four RCTs. The meta-analysis found no significant difference in any of the following parameters: postoperative range of motion for flexion (mean difference for KATKA − MATKA [MD], 1.7 degrees; 95% confidence interval [CI], −1.4 to 4.8 degrees; p = 0.29) and extension (MD, 0.10 degrees; 95% CI, −0.99 to 1.2 degrees; p = 0.86); Oxford Knee Score (MD, 0.10 points; 95% CI, −1.5 to 1.7 points; p = 0.90); Knee Society Score (MD, 1.6 points; 95% CI, −2.8 to 6.0 points; p = 0.49); and Knee Function Score (MD, 1.4 points; 95% CI, −4.9 to 7.8 points; p = 0.66). In addition, there was no significant difference between KATKA and MATKA in the rate of complications requiring reoperation or revision surgery (odds ratio, 1.01; 95% CI, 0.25–4.09; p = 0.99) or in the length of hospital stay (MD, 1.0 days; 95% CI, −0.2 to 2.2 days; p = 0.092). KATKA did not increase the number of patients with poor clinical results due to implant position, particularly for varus placement of the tibial component. In this meta-analysis based on four RCTs with a minimum of 2 years of follow-up, KATKA were only relevant to cruciate retaining TKA and could not be extrapolated to posterior stabilized TKA. Patient-reported outcome measures with KATKA were not superior to those with MATKA.



Author(s):  
LiMing Liu ◽  
Kai Lei ◽  
Xin Chen ◽  
HuaQuan Fan ◽  
Liu Yang ◽  
...  

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.



Author(s):  
Mehmet Emin Simsek ◽  
Mustafa Akkaya ◽  
Safa Gursoy ◽  
Özgür Kaya ◽  
Murat Bozkurt

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.



2021 ◽  
Vol 12 ◽  
pp. 215145932199663
Author(s):  
Mustafa Kaçmaz ◽  
Zeynep Yüksel Turhan

Introduction: Femoral Nerve Block (FNB) and Adductor Canal Block (ACB) methods, which are regional analgesic techniques, are successfully used in postoperative pain control after total knee arthroplasty. This study aimed to compare adductor canal block method that was preoperatively used and femoral nerve block method in total knee arthroplasty (TKA) patients who underwent spinal anesthesia in terms of factors effecting patient satisfaction and determine whether these methods were equally effective or not. Methods: A total of 80 patients between the ages of 60 and 75 who were in the American Society of Anesthesia (ASA) physical status of I-III were prospectively included in this randomized study. Patients (n = 40) who received FNB were called Group FNB and patients (n = 40) who received Adductor Canal Block were called Group ACB. Results: Although mean postoperative VAS values were lower in FNB group only in the first hour (p = 0.02) there was no significant difference between the groups in the third, fifth, seventh, ninth, 12th and 24th hours (p≥0.05). Although Bromage scores were lower in FNB group in the first, second, third, fourth and fifth hours there was no statistically significant difference between the groups (p≥0.05). When mobilization time, patient satisfaction level, time of first analgesia, intraoperative sedation need, and recovery time of sensorial block were compared no statistically significant difference was found (p≥0.05). Discussion: When ACB and FNB that are used for postoperative analgesia in patients who undergo total knee arthroplasty are compared in terms of factors affecting patient satisfaction it is observed that they result in the same level (non-inferiority) of patient satisfaction. Conclusion: We recommend the routine use of ACB method with FNB in total knee arthroplasty. More studies focusing especially on measuring patient satisfaction are needed.



Author(s):  
Masanori Tsubosaka ◽  
Tomoyuki Kamenaga ◽  
Yuichi Kuroda ◽  
Koji Takayama ◽  
Shingo Hashimoto ◽  
...  

AbstractSeveral studies have reported better clinical outcomes following kinematically aligned total knee arthroplasty (KA-TKA) than mechanically aligned TKA. Consistent reproduction of a KA-TKA is aided by accurate tibial bone resections using computer navigation systems. This study compares an accelerometer-based portable navigation system with a conventional navigation system on tibial bone resection and clinical outcomes in KA-TKA. This study included 60 knees of patients who underwent primary KA-TKA between May 2015 and September 2017. They were randomly assigned to the OrthoPilot and iASSIST groups. A tibial bone cut was performed with 3 degree varus and 7 degree posterior slope in relation to the mechanical axis in all cases. The tibial component angle (TCA) and posterior slope angle (PSA) were evaluated by postoperative radiography, and those that deviated more than 2 degree were set as outliers. The clinical outcomes were the knee range of motion (ROM) and 2011 Knee Society Score (KSS) evaluated at 1 year postoperation. The groups were compared in terms of the TCA, PSA, number of outliers, ROM, and 2011 KSS (p < 0.05). No significant difference was observed between the groups in terms of the mean TCA, PSA, number of outliers, ROM, and categories of the 2011 KSS (objective knee indicators, symptoms, satisfaction, expectations, and functional activities). Although tibial bone cuts were performed with 3 degree varus and 7 degree posterior slope, no significant difference was observed between the OrthoPilot and iASSIST groups in terms of the accuracy of cuts or postoperative clinical result. The iASSIST was found to be a simple and useful navigation system for KA-TKA.



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