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

Author(s):  
James D. Sires ◽  
Johnathan D. Craik ◽  
Christopher J. Wilson

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.

2021 ◽  
Author(s):  
Xingye Li ◽  
Zheng Li ◽  
Xiaofeng Zhang ◽  
Lele Ding ◽  
Jun Yan ◽  
...  

Abstract Background Total knee arthroplasty (TKA) is an effective and also mature surgical interventions that improves life quality and provides pain relief. Accurate bone cuts are important to prevent TKA malalignment and it requires cautious preoperative plan and precise bone resection. Recently, robotic-assisted TKA techniques have been used to improve the accuracy of bone resection and implantation. However, the system described above suits for only one prosthesis type. Methods Five types (MicroPort_CS, Smith& Nephew_GII, Johnson&Johnson_PFC_PS, kingnow _VLQX_PS and Akmedical_A3GT_PS) implants were included in our study and three Sawbones models were used for each implant. Procedures were performed by experienced joint replacement surgeons using HURWA robotic-assisted TKA system. Results our study indicated that the bone resection error of HURWA robotic-assisted system was below 0.5 mm (with SDs below 0.3 mm), and all of the bone resection angles were below 0.5° (with SDs below 0.3°). The bone resection angles and levels deviation of different brand prosthesis types were below 0.5 mm (with SDs below 0.3 mm) and below 0.5° (with SDs below 0.3°) respectively. Conclusion It suggested that our system may be suitable for different prosthesis types.


2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Osamu Tanifuji ◽  
Tomoharu Mochizuki ◽  
Hiroshi Yamagiwa ◽  
Takashi Sato ◽  
Satoshi Watanabe ◽  
...  

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.


Osteology ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 92-104
Author(s):  
Arne Kienzle ◽  
Sandy Walter ◽  
Yannick Palmowski ◽  
Stephanie Kirschbaum ◽  
Lara Biedermann ◽  
...  

Background: Periprosthetic joint infection (PJI) is a common yet severe complication after total knee arthroplasty (TKA). Surgical intervention and antibiotic therapy are obligatory to achieve successful, infection-free outcome. Compared to the outcomes after primary TKA, prosthesis failure rates are drastically increased after PJI-dependent revision surgery. Recurrent PJI and aseptic loosening are the most common reasons for prosthesis failure after revision TKA. An open question is the influence of the patients’ gender on long-term prosthesis survival after revision surgery. Additionally, it is unknown whether gender-related parameters and risk factors or differences in treatment are responsible for potential differences in outcome after revision arthroplasty. Patients and Methods: In this report, 109 patients that received TKA revision surgery due to PJI were retrospectively analyzed. We used clinical, paraclinical and radiological examinations to study the influence of gender on the long-term complications aseptic loosening and recurrent PJI after PJI-dependent revision arthroplasty. Results: While overall prosthesis failure rates and risk of recurrent PJI did not differ between genders, the long-term risk of aseptic loosening was significantly elevated in female patients. Postoperative coronal alignment was significantly more varus for women later diagnosed with aseptic loosening. Besides coronal alignment, no gender-dependent differences in clinical presentation or treatment were observed. Conclusions: Female patients displayed a significantly increased risk for aseptic loosening after PJI-dependent revision TKA. The observed gender-dependent differences in long-term outcome in our study support theories surrounding the role of bone metabolism in the development of aseptic loosening. Our data suggest that further research on a female design for PJI-dependent revision prostheses is warranted.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Vicente J. León-Muñoz ◽  
Silvio Manca ◽  
Mirian López-López ◽  
Francisco Martínez-Martínez ◽  
Fernando Santonja-Medina

AbstractIndividualized pre-operative assessment of the patterns of the lower extremity anatomy and deformities in patients undergoing total knee arthroplasty seems essential for a successful surgery. In the present study, we investigated the relationship among the coronal alignment and the rotational profile of the lower extremities in the Caucasian population with end-stage knee osteoarthritis. We conducted a prospective study of 385 knees that underwent a pre-operative three-dimensional computed tomography-based model. The lower extremity alignment was determined (mechanical tibiofemoral or hip-knee-ankle angle, supplementary angle of the femoral lateral distal angle, and proximal medial tibial angle). For each case, the femoral distal rotation (condylar twist angle), the femoral proximal version, and the tibial torsion were determined. As the coronal alignment changed from varus to valgus, the femoral external rotation increased (r = 0.217; p < 0.0005). As the coronal alignment changed from varus to valgus, the external tibial torsion increased (r = 0.248; p < 0.0005). No correlation was found between the global coronal alignment and the femoral version. The present study demonstrates a linear relationship between the coronal alignment and the rotational geometry of the distal femur. This correlation also occurs with the tibial torsion. Perhaps outcomes of total knee arthroplasty surgery might be improved by addressing these deformities as well.


2020 ◽  
Author(s):  
Akihito Takubo ◽  
Keinosuke Ryu ◽  
Takanori Iriuchishima ◽  
Masahiro Nagaoka ◽  
Yasuaki Tokuhashi ◽  
...  

Abstract Background When the surgeons perform total knee arthroplasty (TKA), PT and LCL iatrogenic injury are worried because those femoral footprints are relatively close to the bone resection lesion. The purpose of this study was to evaluate the distance between PT or LCL footprint and TKA implant using the three-dimensional (3D) template system.Methods Eighteen non-paired formalin fixed cadaveric lower limbs were used. All the surrounded soft tissue except the PT and knee ligaments were removed from the limb. Careful dissection of the PT and LCL was performed, and those femoral footprints were detected. Each footprint was periphery marked with a K-wire. CT scanning of the whole lower limb was then performed. The CT data was analyzed with 3D template system. Simulated models of TKA were Journey II BCS and Persona PS. The area of each footprint, and the length between most distal or posterior point of femur and the edge of each footprint were measured. When the implant model was matched to the CT image, the shortest length between each footprint and the bone resection were evaluated.Results The area of PT and LCL footprint were, 38.7±17.7mm 2 , and 58±24.6mm 2 , respectively. The length between most distal or posterior point of femur and the edge of the PT footprint were 10.3±2.4mm, and 14.2±2.8mm, respectively. The length between most distal or posterior point of femur and the edge of the LCL footprint were 16.3±2.3mm, and 15.5±3.3mm, respectively. When simulated the TKA, the shortest length between PT footprint and bone resection lesion of Journey II BCS and Persona PS were, 4.3±2.5mm, and 3.2±2.9mm, respectively. The shortest length between PT footprint and bone resection lesion of Journey II BCS and Persona PS were, 7.2±2.3mm, and 5.6±2.1mm, respectively. PT footprint was suffered by the bone resection of Journey II BCS TKA in 3 knees, and also by the Persona PS’s bone resection in 9 knees.Conclusion The PT and LCL femoral footprint existed close to the femoral bone resection lesion of the TKA. Careful attention is needed not to injure the PT and LCL in the surgical procedures.


2017 ◽  
Vol 30 (09) ◽  
pp. 936-942 ◽  
Author(s):  
Yunjie Zhang ◽  
Xiaofeng Wang ◽  
Zongming Wu ◽  
Qing Xia ◽  
Yunchao Shao

AbstractWe aimed to retrospectively investigate the morphology of the resected surfaces of femurs in Chinese patients who underwent total knee arthroplasty (TKA) and to assess the suitability of contemporary femoral components. Measurements on three-dimensional reconstruction after virtual bone cutting were performed on 142 knees from Chinese TKA candidates. The anteroposterior (AP) and mediolateral (ML) dimensions, aspect ratio (ML/AP), and posterior condylar angle (PCA) were measured in the axial plane; the height and length of medial and lateral anterior condyles and the maximal width of the anterior condyles were measured in the frontal plane. Femurs were matched to the prosthesis with the closest AP size. The ML dimensions of femurs were compared with the ML dimensions of the prosthesis. The AP and ML dimensions were significantly larger in male knees (p < 0.01), whereas the difference of aspect ratios was not found to be significantly different between genders (p = 0.26). Both medial and lateral heights of the anterior condyles were significantly higher in men after normalization by AP (p < 0.01 and p < 0.05, respectively). The mean PCA averaged 3.8 degrees for Chinese subjects. The overall prevalence of clinically significant overhang was 6.4% in males and 4.8% in females. The design of femoral prosthesis with alternative ML dimensions of the femoral component is a solution to sufficiently avoid overhang while retaining ideal coverage when dealing with a high variation. Chinese men had higher anterior condyles than women after normalization by AP dimension. The mean PCA was 3.8 degrees for all patients with high variability.


Author(s):  
Kenneth H. Downing

Three-dimensional structures of a number of samples have been determined by electron crystallography. The procedures used in this work include recording images of fairly large areas of a specimen at high tilt angles. There is then a large defocus ramp across the image, and parts of the image are far out of focus. In the regions where the defocus is large, the contrast transfer function (CTF) varies rapidly across the image, especially at high resolution. Not only is the CTF then difficult to determine with sufficient accuracy to correct properly, but the image contrast is reduced by envelope functions which tend toward a low value at high defocus.We have combined computer control of the electron microscope with spot-scan imaging in order to eliminate most of the defocus ramp and its effects in the images of tilted specimens. In recording the spot-scan image, the beam is scanned along rows that are parallel to the tilt axis, so that along each row of spots the focus is constant. Between scan rows, the objective lens current is changed to correct for the difference in specimen height from one scan to the next.


2019 ◽  
Vol 50 (4) ◽  
pp. 693-702 ◽  
Author(s):  
Christine Holyfield ◽  
Sydney Brooks ◽  
Allison Schluterman

Purpose Augmentative and alternative communication (AAC) is an intervention approach that can promote communication and language in children with multiple disabilities who are beginning communicators. While a wide range of AAC technologies are available, little is known about the comparative effects of specific technology options. Given that engagement can be low for beginning communicators with multiple disabilities, the current study provides initial information about the comparative effects of 2 AAC technology options—high-tech visual scene displays (VSDs) and low-tech isolated picture symbols—on engagement. Method Three elementary-age beginning communicators with multiple disabilities participated. The study used a single-subject, alternating treatment design with each technology serving as a condition. Participants interacted with their school speech-language pathologists using each of the 2 technologies across 5 sessions in a block randomized order. Results According to visual analysis and nonoverlap of all pairs calculations, all 3 participants demonstrated more engagement with the high-tech VSDs than the low-tech isolated picture symbols as measured by their seconds of gaze toward each technology option. Despite the difference in engagement observed, there was no clear difference across the 2 conditions in engagement toward the communication partner or use of the AAC. Conclusions Clinicians can consider measuring engagement when evaluating AAC technology options for children with multiple disabilities and should consider evaluating high-tech VSDs as 1 technology option for them. Future research must explore the extent to which differences in engagement to particular AAC technologies result in differences in communication and language learning over time as might be expected.


2010 ◽  
Vol 26 (1) ◽  
pp. 3-10 ◽  
Author(s):  
Nale Lehmann-Willenbrock ◽  
Simone Kauffeld

In research on trust in the organizational context, there is some agreement evolving that trust should be measured with respect to various foci. The Workplace Trust Survey (WTS) by Ferres (2002) provides reliable assessment of coworker, supervisor, and organizational trust. By means of a functionally equivalent translation, we developed a German version of the questionnaire (G-WTS) comprising 21 items. A total of 427 employees were surveyed with the G-WTS and questionnaires concerning several work-related attitudes and behaviors and 92 of these completed the survey twice. The hypothesized three-dimensional conceptualization of organizational trust was confirmed by confirmatory factor analysis. The G-WTS showed good internal consistency and retest reliability values. Concerning convergent validity, all of the three G-WTS dimensions positively predicted job satisfaction. In terms of discriminant validity, Coworker Trust enhanced group cohesion; Supervisor Trust fostered innovative behavior, while Organizational Trust was associated with affective commitment. Theoretical and practical contributions as well as opportunities for future research with the G-WTS are discussed.


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.


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