Accelerometer-Based Portable Navigation System Is Useful for Tibial Bone Cutting in Modified Kinematically Aligned Total Knee Arthroplasty

2019 ◽  
Author(s):  
Masanori Tsubosaka ◽  
Tomoyuki Kamenaga ◽  
Yuichi Kuroda ◽  
Koji Takayama ◽  
Shingo Hashimoto ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Clinical Outcomes ◽  
Knee Arthroplasty ◽  
Navigation System ◽  
Slope Angle ◽  
Posterior Slope ◽  
Tibial Bone ◽  
Significant Difference ◽  
Portable Navigation ◽  
Total Knee

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.

scholarly journals Gap difference in navigated TKA: a measure of the imbalanced flexion-extension gap

SICOT-J ◽  
2018 ◽  
Vol 4 ◽  
pp. 30 ◽  
Author(s):  
Zi-Yang Chia ◽  
Hee-Nee Pang ◽  
Mann-Hong Tan ◽  
Seng-Jin Yeo
Keyword(s):  
Total Knee Arthroplasty ◽  
Social Functioning ◽  
Clinical Outcomes ◽  
Knee Arthroplasty ◽  
Computer Calculation ◽  
Bodily Pain ◽  
Significant Difference ◽  
Flexion Extension ◽  
Total Knee ◽  
The Mean

Introduction: The success of Total Knee Arthroplasty (TKA) hinges on balanced flexion-extension gaps. This paper aims to evaluate the correlation between imbalanced gaps and clinical outcomes, and hence help quantify the imbalanced gap in navigation-assisted total knee arthroplasty. Methods: We studied 195 knees with an average follow-up of two years. Flexion-extension gaps were obtained from computer calculation upon cementation of implants in both flexion (90°) and extension. The gap difference (GD) was defined as the measured difference between the gaps in flexion and extension. Results: At 2 years after surgery, the mean ROM in the balanced group, with GD less than or equal to 2 mm, was 115.1° ± 16.6° and the mean ROM in the imbalanced group was 116.7° ± 12.1°. This was not statistically significant with p-value 0.589. Balanced flexion-extension gaps also did not show significant difference in terms of mechanical alignment, with 0.29 ± 0.89 in the balanced group at 2 years, and 0.65 ± 1.51 in the imbalanced group with p-value 0.123. Balanced gaps however, were associated with improved outcomes in terms of physical functioning, bodily pain, social functioning, Oxford and Knee scores at 6 months and improved social functioning scores at 2 years. Conclusions: Computer navigation is a useful tool for assessing the gap balance in TKA. Balanced flexion-extension gaps, with gap differences of less than or equal to 2 mm, is associated with improved clinical outcomes at 6 months.

scholarly journals The iAssist Navigation System Demonstrated Superior Radiological Outcomes in Restoring Mechanical Alignment and Component Sagittal Positioning in Total Knee Arthroplasty

2020 ◽  
Author(s):  
Jiaxiang Gao ◽  
Yunfei Hou ◽  
Zhichang Li ◽  
Runjun Li ◽  
Yan Ke ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Clinical Outcomes ◽  
Knee Arthroplasty ◽  
Navigation System ◽  
Clinical Parameters ◽  
Mechanical Alignment ◽  
Absolute Deviation ◽  
Total Knee ◽  
The Absolute

Abstract Background: This study aimed to determine whether the iAssist navigation system (NAV) could improve the accuracy of restoring mechanical axis (MA), component positioning, and clinical outcomes compared to conventional (CON) total knee arthroplasty (TKA). Methods: A total of 301 consecutive patients (NAV: 27, CON: 274) were included. A 1:4 propensity score matching (PSM) was performed between the two groups according to preoperative demographic and clinical parameters. The postoperative MA, femoral coronal angle (FCA), femoral sagittal angle (FSA), tibial coronal angle (TCA) and tibial sagittal angle (TSA) were compared. Absolute deviations of aforementioned angles were calculated as the absolute value of difference between the exact and ideal value and defined as appropriate if within 3°, otherwise regarded as outliers. Additional clinical parameters, including the Knee Society knee and function scores (KSKS and KSFS) and range of motion (ROM), were assessed at the final follow-up (mean follow-up time was 21.88 and 21.56 months respectively for NAV and CON group). Results: A total of 98 patients/102 knees were analyzed after the PSM (NAV: 21 patients/24 knees, CON: 77 patients/78 knees). In the NAV group, the mean MA, FCA and TSA were significantly improved (p = 0.019, 0.006, <0.001, respectively). Proportions of TKAs within a ±3°deviation were significantly improved in all the postoperative radiological variables except for TCA (p = 0.003, 0.021, 0,017, 0.013, respectively for MA, FCA, FSA, and TSA). The absolute deviations of FSA and TSA were also significantly lower in the NAV group (p = 0.016, 0.048, respectively). In particular, no significant differences were found in either mean value, absolute deviation or outlier ratio of TCA between two groups. For the clinical outcomes, there were no significant differences between two groups, although KSKS, KSFS and ROM (p<0.01, respectively) dramatically improved compared to baseline. Conclusions: We suggested that the iAssist system could improve the accuracy and precision of mechanical alignment and component positioning without significant improvement of clinical outcomes. Further long-term high-quality studies are necessary to validate the results.

scholarly journals Ángulo de pendiente tibial posterior “Slope” en prótesis total de rodilla. Diferencias entre alineación Intra o Extramedular y su repercusión sobre el rango de movilidad postoperatorio.

2019 ◽  
pp. 143-148
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Slope Angle ◽  
Tibial Slope ◽  
Posterior Tibial Slope ◽  
Posterior Slope ◽  
Posterior Tibial ◽  
Total Knee ◽  
The Mean ◽  
Posterior Slope Angle

Introduction: The aim of this work was to compare the posterior tibial slope of the tibial component after performing a total knee arthroplasty, as an intramedullary or extramedullary guide was used during the surgical technique, as well as comparing the range of mobility obtained according to the Instrumentation used. Material and methods: We conducted a descriptive, retrospective, observational study of a series of 57 patients operated in our Center during 2012 and 2013, with the same model of total knee arthroplasty (Sigma PS® DePuy), divided into two homogeneous groups in terms of age, sex, degree of osteoarthritis evolution, the first with patients operated by extramedullary guidance and the second by intramedullary guidance. A radiographic study was performed, measuring the posterior slope angle in the sagittal plane. The range of mobility achieved after arthroplasty and implant survival was studied. Results: Together, in both groups, measurements of the posterior slope angle were made, which was 4.35º preoperative average. In groups, the mean postoperative posterior fall angle was 4.04 ° in the patients who underwent an EM guide, while those who underwent an IM guide the mean was 1.76 °; the differences being statistically significant. The range of mobility in the ATRs operated by intramedullary guidance was 102.7º on average (range 80-125º), while in the group where the extramedullary guide was used, it was 104.3º (range 80-130º) no these differences being statistically significant. Regarding the survival of the implant, during the study period two cases of patients undergoing surgery for the replacement of prostheses were found, both of which belonged to the “Extramedullary guide” group. Conclusion: The posterior drop angle, for the same PS prosthesis model, was statistically different according to the guide used, being within the 3-7º range in the group where the extramedullary guide was used; but despite these differences, no impact on the range of mobility was observed. Currently, it is recommended to restore the patient's posterior tibial slope, and in cases with a slope greater than 10º use a PS ATR.

scholarly journals Effects of Different Prosthetic Instrumentations on Tibial Bone Resection in Total Knee Arthroplasty

2020 ◽  
Author(s):  
Yufeng Lu ◽  
Xuechao Yuan ◽  
Feng Qiao ◽  
Yangquan Hao
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Knee Prosthesis ◽  
Tibial Slope ◽  
Full Length ◽  
Bone Resection ◽  
Tibial Bone ◽  
Significant Difference ◽  
Total Knee ◽  
Alignment Angle

Abstract Objective For total knee arthroplasty (TKA) tibial bone resection, various manufacturers provide cutting blocks with fixed angles. But the accuracy of these angles is uncertain. Our aim was to assess the accuracy of the obtained posterior tibial slope (PTS) with a fixed angle cutting block.Methods 247 TKAs in 213 patients were reviewed. We included 104 Legion Prosthesis, 76 U2 Knee Prosthesis, 46 NexGen LPS-Flex Prosthesis, and 21 Vanguard Knee System products. Preoperative and postoperative PTS were measured via expanded lateral tibia radiographs. The tibial component coronal alignment angle (TCCA) was measured on postoperative standing full-length anteroposterior radiographs, and the tibia length was measured on preoperative standing full-length radiographs. Results For postoperative PTS, the Legion group had significantly smaller slopes than the U2 Knee group and Vanguard group. However, there was no significant difference between the Legion and NexGen groups, and no significant difference among the NexGen, U2 Knee, and Vanguard groups. One sample t-test indicated that only the NexGen group showed no statistical difference from the 7° PTS and 90° TCCA it aimed to provide. Multiple linear regression showed that the different tibial lengths and preoperative PTS had statistically significant effect on postoperative PTS. However, there were weak correlations between the tibial length and PTS, and between preoperative and postoperative PTS.Conclusion For TKA, using conventional tibial bone resection technology with different tibial cutting instrumentations provided by various manufacturers can obtain safe PTS. However, the PTS is not completely consistent with the angle of the cutting block.

Usefulness of an accelerometer-based portable navigation system in total knee arthroplasty

2017 ◽  
Vol 99-B (8) ◽  
pp. 1047-1052 ◽  
Author(s):  
T. Ikawa ◽  
S. Takemura ◽  
M. Kim ◽  
K. Takaoka ◽  
Y. Minoda ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Navigation System ◽  
Portable Navigation ◽  
Total Knee
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