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Mechanical Axis Deviation of both Treatment Groups Measured by Orthoroentgenogram and Navigation Systems
Source publication
The purpose of this study is to compare and analyze the precision of optical and electromagnetic navigation systems in total knee arthroplasty (TKA).
We retrospectively reviewed 60 patients who underwent TKA using an optical navigation system and 60 patients who underwent TKA using an electromagnetic navigation system from June 2010 to March 2012....
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Objective:
To determine the ideal angle for making the distal femoral cut in total knee arthroplasty in a Brazilian population.
Methods:
Panoramic radiographs of the lower limbs bearing weight from 79 patients (57 women and 22 men) were studied, totaling 107 knees with an indication for total knee arthroplasty. The femoral anatomical axis, femor...
Citations
... Several resection planning and validation tools are currently available, each with its own advantages and limitations [22][23][24][25][26][27]. At the most basic level, surgical cutting jigs can be configured to guide a bone saw to produce a planar resection surface on either the distal femur or the proximal tibia whose orientation in space is fully specified with respect to the three standard anatomical planes (sagittal, coronal, and transverse). ...
... radio frequency) navigation to achieve accuracy better than AE1 [28]. Increased operating room (OR) time for registration and planning as well as high capital costs are, however, distinct barriers to widespread adoption [22,[24][25][26][27][29][30][31][32][33][34][35][36][37]. Robot-assisted knee surgery also provides an opportunity for both specifying and validating resection plane orientation, offering tibial alignment accuracy on the order of AE1 , but like tracked navigation requiring significant capital investment and imposing a learning curve on OR time [38][39][40]. ...
Coronal plane alignment in total knee arthroplasty (TKA) is an important predictor of clinical outcomes including patient satisfaction and device longevity. Radiography and computer assisted navigation are the two primary technologies currently available to surgeons for intraoperative assessment of alignment; however, neither is particularly well-suited for use in this increasingly high volume procedure. Herein we propose a novel gyroscope-based instrument for intraoperative validation of tibia coronal plane alignment, and provide initial analytical and experimental performance assessments. The gyroscope-based alignment estimate is derived from simplified joint geometry and verified experimentally using a custom tibial trial insert containing a consumer-grade inertial measurement unit (IMU). Average accuracy of the gyroscope-based tibia coronal angle estimate was found to be within ±1º in mechanical leg jig and cadaver testing. These results indicate that the proposed gyroscope-based method shows promise for low cost, accurate intraoperative validation of limb alignment in TKA patients. Integrating IMU technology into the TKA surgical workflow via low-cost instrumentation will enable surgeons to easily validate implant alignment in real time, thereby reducing cost, operating room time, and future revision burden.
... They are widely employed in the field of otorhinolaryngology [149] and dental navigation systems [150], [151] as well. The main application in the orthopaedic field include spine surgery [152], pedicle screw fixation [153], alignment of long-bone fractures, alignment of knee and hip implants [154] [155], and osteotomy [156]. Optical-based systems have also been used in Anterior Cruciate Ligament Reconstruction (ACLR) surgery [157]. ...
... In [154] the authors compared optical (OrthoSoft, Zimmer CAS) and electromagnetic-based (AxiEM, Medtronic) SNSs application accuracy versus preoperative radiological measurements for tracking the mechanical alignment in total-knee arthroplasty. The discrepancy with radiological measurement was more evident for electromagneticbased SNSs, even if the authors did not find statistical differences between the two tracking systems. ...
... . The study showed little differences in the accuracy of optical and electromagnetic tracking systems [154] OrthoSoft (optical SNS) and AxiEM (electromagnetic SNS) ...
Optical and electromagnetic tracking systems represent the two main technologies integrated into commercially-available surgical navigators for computer-assisted image-guided surgery so far. Optical Tracking Systems (OTSs) work within the optical spectrum to track the position and orientation, i.e. pose of target surgical instruments. OTSs are characterized by high accuracy and robustness to environmental conditions. The main limitation of OTSs is the need of a direct line-of-sight between the optical markers and the camera sensor, rigidly fixed into the operating theatre. Electromagnetic Tracking Systems (EMTSs) use electromagnetic field generator to detect the pose of electromagnetic sensors. EMTSs do not require such a direct line-of-sight, however the presence of metal or ferromagnetic sources in the operating workspace can significantly affect the measurement accuracy. The aim of the proposed review is to provide a complete and detailed overview of optical and electromagnetic tracking systems, including working principles, source of error and validation protocols. Moreover commercial and research-oriented solutions, as well as clinical applications, are described for both technologies. Finally a critical comparative analysis of the state of the art which highlights the potentialities and the limitations of each tracking system for a medical use is provided.
Optical surgical navigation system has been a hot research topic because of its high accuracy. This paper focuses on identifying and tracking multiple surgical instruments to meet the requirements of applying multiple surgical instruments in clinical medicine. The methods of instrument identification based on the marker's geometrical arrangement and instrument tracking based on markers’ motion vector were applied in the proposed algorithm. The experiments of multiple instruments’ identification and tracking, the instruments’ stability, the space distance and rotation of a pair of instruments at the same tracking time were performed to verify the proposed algorithm. The stereoscopic camera is applied to capture images, and two 850 nm filters are added in front of the binocular camera. The tracking experiment shows that ten instruments can be fully and accurately identified, and then all of them can be quickly and accurately tracked at the same time. A pair of instruments is simultaneously measured in the stability test, such as the typical surgical instrument (TSI) and the miniature surgical instrument (MSI). The ranges of standard deviations (SD) of the stability test for the TSI in the X-, Y-, and Z- axes are from 0.016 mm to 0.127 mm, from 0.011 mm to 0.090 mm, and from 0.124 mm to 0.901 mm, respectively. And the ranges of SDs for the MSI’s stability test are from 0.011 mm to 0.133 mm in the X-axis, from 0.010 mm to 0.106 mm in the Y-axis, and from 0.093 mm to 0.932 mm in the Z-axis. The sub-millimeter SDs show that the proposed algorithm has a high stability. Moreover, the space distance test and the rotation test were performed for simultaneously tracking TSI and MSI. All experimental results indicate the proposed algorithm is able to meet the clinical accuracy requirements.
Purpose:
In modern craniofacial surgery, the accuracy of osteotomies plays a central role in surgical technique. To reach a higher level of accuracy, many centers use virtual presurgical planning. In the past decade, some surgeons also have applied navigational approaches to craniofacial procedures. In this work, a novel protocol for surgical planning and intraoperative navigation is described and validated in a preclinical setting to determine its accuracy in guiding osteotomies.
Materials and methods:
This study was based on planning a set of osteotomies using 3-dimensional models of computed tomographic images of human skulls. The planned osteotomies were reproduced on real skulls using an optical infrared navigation system. Positions of the performed osteotomies and planned osteotomies were compared. Results were described as the mean positional error and as a Lin concordance coefficient. The Bland-Altman interval of agreement also was defined to assess a range that could include 95% of possible errors.
Results:
The mean error was 0.044 mm (95% confidence interval [CI], -0.128 to +0.216), the Lin concordance interval was 0.999 (95% CI, 0.999-1.000), and the Bland-Altman limit of agreement ranged from -1.500 to +1.589 mm.
Conclusions:
These results show a submillimetric mean error and a very narrow interval of agreement, providing preclinical validation of this new protocol and suggesting that it could be applied in a clinical setting.
Purpose:
To examine, with a navigation, whether the final component alignments correlate with alignment of the bone resection surfaces in cemented total knee arthroplasty (TKA), and to evaluate the factors affecting alignment deviation.
Methods:
A total of 222 patients (276 knees) who underwent navigation-assisted TKA between September 2012 and January 2014 due to osteoarthritis were retrospectively reviewed. The deviation between the alignment of bone resection surfaces and the final alignment of femoral and tibial components was measured. Factors associated with alignment deviation of greater than 2° (outliers) were evaluated. These included age, sex, body mass index, bone mineral density (T score), preoperative and postoperative mechanical femorotibial angle, preoperative and postoperative flexion contractures, and the difference between medial and lateral gaps in knee extension or flexion.
Results:
Outliers consisted of 24 cases (8.6%) on the femoral coronal plane, 4 cases (1.4%) on the tibial coronal plane, and 48 cases (17.4%) on the tibial sagittal plane. In the coronal plane (femur and tibia), the outliers were associated with preoperative [p < 0.001; odds ratio (OR) 0.774; 95% confidence interval (CI) 0.672-0.891] and postoperative (p < 0.001; OR 0.240; 95% CI 0.123-0.468) flexion contractures; a difference of 3 mm or more between the medial and lateral gaps in knee extension (p < 0.041; OR 5.805; 95% CI 1.075-31.343); and a T score of less than -2.5(p < 0.024; OR 5.899; 95% CI 1.258-27.664). In the sagittal plane of the tibia, the outliers were associated with preoperative (p < 0.001; OR 0.886; 95% CI 0.829-0.946) and postoperative (p < 0.031; OR 0.803; 95% CI 0.659-0.980) flexion contractures.
Conclusion:
There was a deviation between the alignments of the bone resection surfaces and the final alignments of components. With larger preoperative and postoperative flexion contractures in the coronal and sagittal planes, there were more outlier risks. The outliers in the coronal plane were associated with a difference of 3 mm or more between the medial and lateral gaps in knee extension and poor bone quality. Awareness of such alignment deviation and related factors can help diminish the outliers after TKA.
Level of evidence:
IV.
Purpose
This meta-analysis was designed to evaluate the effects of computer navigation on blood conservation after total knee arthroplasty (TKA) by comparing postoperative blood loss and need for allogenic blood transfusion in patients undergoing computer navigation and conventional primary TKAs.
Methods
Studies were included in this meta-analysis if they compared change in haemoglobin concentration before and after surgery, postoperative blood loss via drainage or calculated total blood loss, and/or allogenic blood transfusion rate following TKA using computer navigation and conventional methods. For all comparisons, odds ratios and 95 % confidence intervals (CI) were calculated for binary outcomes, while mean difference and 95 % CI were calculated for continuous outcomes.
Results
Twelve studies were included in this meta-analysis. The change in haemoglobin concentration was 0.39 g/dl lower with computer navigation than with conventional TKA (P = 0.006). Blood loss via drainage was 83.1 ml (P = 0.03) lower and calculated blood loss was 185.4 ml (P = 0.002) lower with computer navigation than with conventional TKA. However, the need for blood transfusion was similar for the two approaches (n.s.).
Conclusions
The primary TKA with computer navigation was effective in reducing haemoglobin loss and blood loss, but had no effect on transfusion requirement, compared with conventional primary TKA. These findings suggest the importance of analysing several blood loss parameters, because each may not always accurately reflect true postsurgical bleeding.
Level of evidence
Meta-analysis, Level III.
