scholarly journals Bony Landmarks for Determining the Mechanical Axis of the Femur in the Sagittal Plane during Total Knee Arthroplasty

2009 ◽  
Vol 1 (3) ◽  
pp. 128 ◽  
Author(s):  
Jai-Gon Seo ◽  
Byung-Kuk Kim ◽  
Young-Wan Moon ◽  
Jong-Hyun Kim ◽  
Byeong-Ho Yoon ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Mechanical Axis ◽  
Sagittal Plane ◽  
Bony Landmarks ◽  
Total Knee

Comparative Study for Alignment of Extramedullary Guides versus Portable, Accelerometer-Based Navigation in Total Knee Arthroplasty

2017 ◽  
Vol 31 (01) ◽  
pp. 092-098 ◽  
Author(s):  
Kazu Matsumoto ◽  
Masashi Fukuta ◽  
Nobuyuki Mori ◽  
Haruhiko Akiyama ◽  
Hiroyasu Ogawa
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Mechanical Axis ◽  
Sagittal Plane ◽  
Sagittal Alignment ◽  
Coronal Alignment ◽  
Technical Improvement ◽  
Primary Tkas ◽  
Total Knee ◽  
Alignment Angle

AbstractThe use of portable, accelerometer-based navigation (PN) devices for positioning of the components of total knee arthroplasty (TKA) is emerging as an alternative to standard extramedullary (EM) systems, which was needed to the image intensifier. The aim of our study was to compare the accuracy of component positioning in TKA using an EM and PN systems. Data from 100 consecutive primary TKAs, performed by multiple surgeons in 87 patients between October 2010 and June 2015, were analyzed. Coronal and sagittal plane alignments of the TKA components, relative to the mechanical axis of the limb, were evaluated by radiography. The mean postoperative coronal alignment angle of the femoral (α) and tibial (β) components was comparable between the groups (α: PN, 89.9 ± 2.2 degrees; EM, 89.9 ± 1.6 degrees and β: PN, 90.1 ± 1.4 degrees; EM, 89.6 ± 1.3 degrees). Groups were also comparable with regard to mean postoperative sagittal alignment angle of the femoral and tibial components (γ: PN, 2.3 ± 3.3 degrees; EM, 1.8 ± 1.7 degrees and σ: PN, 89.7 ± 2.5 degrees; EM, 90.1 ± 1.3 degrees). The incidence rate of a component malalignment > 3 degrees in the coronal and sagittal planes of the mechanical axis of the knee was comparable between the groups. In conclusion, the coronal and sagittal alignments for the femoral components was less accurate compared with tibial component alignment, especially in the PN group, and the sagittal alignment of the femoral component was less accurate than coronal alignment for both groups. Both the PN and EM systems provide satisfactory coronal and sagittal component alignments in TKA. Further technical improvement of the PN system could further improve its application for accurate component implantation in TKAs.

scholarly journals Pros and cons of navigated versus conventional total knee arthroplasty—a retrospective analysis of over 2400 patients

2021 ◽  
Author(s):  
Matthias Meyer ◽  
Tobias Renkawitz ◽  
Florian Völlner ◽  
Achim Benditz ◽  
Joachim Grifka ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Retrospective Analysis ◽  
Outcome Measures ◽  
Knee Arthroplasty ◽  
Mechanical Axis ◽  
Complication Rates ◽  
Total Knee ◽  
One Year ◽  
Navigated Tka ◽  
Surgery Duration

Abstract Introduction Because of the ongoing discussion of imageless navigation in total knee arthroplasty (TKA), its advantages and disadvantages were evaluated in a large patient cohort. Methods This retrospective analysis included 2464 patients who had undergone TKA at a high-volume university arthroplasty center between 2012 and 2017. Navigated and conventional TKA were compared regarding postoperative mechanical axis, surgery duration, complication rates, one-year postoperative patient-reported outcome measures (PROMs) (WOMAC and EQ-5D indices), and responder rates as defined by the criteria of the Outcome Measures in Rheumatology and Osteoarthritis Research Society International consensus (OMERACT-OARSI). Results Both navigated (1.8 ± 1.6°) and conventional TKA (2.1 ± 1.6°, p = 0.002) enabled the exact reconstruction of mechanical axis. Surgery duration was six minutes longer for navigated TKA than for conventional TKA (p < 0.001). Complication rates were low in both groups with comparable frequencies: neurological deficits (p = 0.39), joint infection (p = 0.42 and thromboembolic events (p = 0.03). Periprosthetic fractures occurred more frequently during conventional TKA (p = 0.001). One-year PROMs showed excellent improvement in both groups. The WOMAC index was statistically higher for navigated TKA than for conventional TKA (74.7 ± 19.0 vs. 71.7 ± 20.7, p = 0.014), but the increase was not clinically relevant. Both groups had a similarly high EQ-5D index (0.23 ± 0.24 vs. 0.26 ± 0.25, p = 0.11) and responder rate (86.5% [256/296] vs. 85.9% [981/1142], p = 0.92). Conclusion Both methods enable accurate postoperative leg alignment with low complication rates and equally successful PROMs and responder rates one year postoperatively. Level of evidence III. Retrospective cohort study.

scholarly journals Postoperative laxity of the lateral soft tissue is largely negligible in total knee arthroplasty for varus osteoarthritis

2021 ◽  
Vol 29 (1) ◽  
pp. 230949902110020
Author(s):  
Seikai Toyooka ◽  
Hironari Masuda ◽  
Nobuhiro Nishihara ◽  
Takashi Kobayashi ◽  
Wataru Miyamoto ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Soft Tissue ◽  
Knee Arthroplasty ◽  
Mechanical Axis ◽  
Varus Deformity ◽  
Varus Knee ◽  
Before And After ◽  
Knee Deformity ◽  
Varus Stress ◽  
Total Knee

Purpose: To evaluate the integrity of lateral soft tissue in varus osteoarthritis knee by comparing the mechanical axis under varus stress during navigation-assisted total knee arthroplasty before and after compensating for a bone defect with the implant. Methods: Sixty-six knees that underwent total knee arthroplasty were investigated. The mechanical axis of the operated knee was evaluated under manual varus stress immediately after knee exposure and after navigation-assisted implantation. The correlation between each value of the mechanical axis and degree of preoperative varus deformity was compared by regression analysis. Results: The maximum mechanical axis under varus stress immediately after knee exposure increased in proportion to the degree of preoperative varus deformity. Moreover, the maximum mechanical axis under varus stress after implantation increased in proportion to the degree of preoperative varus deformity. Therefore, the severity of varus knee deformity leads to a progressive laxity of the lateral soft tissue. However, regression coefficients after implantation were much smaller than those measured immediately after knee exposure (0.99 vs 0.20). Based on the results of the regression formula, the postoperative laxity of the lateral soft tissue was negligible, provided that an appropriate thickness of the implant was compensated for the bone and cartilage defect in the medial compartment without changing the joint line. Conclusion: The severity of varus knee deformity leads to a progressive laxity of the lateral soft tissue. However, even if the degree of preoperative varus deformity is severe, most cases may not require additional procedures to address the residual lateral laxity.

scholarly journals Bone Cement Solidifiliation Influence the Limb Alignment and Gap Balance during TKA

2015 ◽  
Vol 2015 ◽  
pp. 1-3 ◽  
Author(s):  
Dongquan Shi ◽  
Xingquan Xu ◽  
Anyun Guo ◽  
Jin Dai ◽  
Zhihong Xu ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Bone Cement ◽  
Knee Arthroplasty ◽  
Mechanical Axis ◽  
Statistical Significance ◽  
Mechanical Alignment ◽  
Early Loosening ◽  
Flexion Extension ◽  
Before And After ◽  
Total Knee

Introduction. Mechanical alignment deviation after total knee arthroplasty is a major reason for early loosening of the prosthesis. Achieving optimum cement penetration during fixation of the femoral and tibial component is an essential step in performing a successful total knee arthroplasty. Bone cement is used to solidify the bone and prosthesis. Thickness imbalance of bone cement leads to the deviation of mechanical alignment. To estimate the influence of bone cement, a retrospective study was conducted.Materials and Methods. A total of 36 subjects were studied. All the TKA were performed following the standard surgical protocol for navigated surgery by medial approach with general anaesthesia. Prostheses were fixed by bone cement.Results. We compared the mechanical axis, flexion/extension, and gap balance before and after cementation. All the factors were different compared with those before and after cementation. Internal rotation was reached with statistical significance (P=0.03).Conclusion. Bone cement can influence the mechanical axis, flexion/extension, and gap balance. It also can prompt us to make a change when poor knee kinematics were detected before cementation.

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.

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