Plain Radiograph Fails to Reflect the Alignment and Advantages of Navigation in Total Knee Arthroplasty (original) (raw)
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Background: The purpose of this study was to assess the degree of mismatch between intraoperative navigation data using imageless computer navigation and post-operative CT scan measurements with respect to bone cuts, component and limb alignment during TKA. Methods: Intraoperative navigation data including bone cut verification and overall limb alignment during TKA was compared to postoperative CT measurements of component and limb alignment according to the Perth protocol. The proportion of cases with mismatch between navigation and CT measurements at two and three degree thresholds was identified. Results: In a total sample of 50 primary TKAs, 20% of cases showed a mismatch of more than two degrees between navigation and CT obtained measurements for coronal femoral alignment, 42% for femoral rotation, 16% for tibial component coronal alignment and 32% for overall limb alignment. Conclusion: Mismatch between intraoperative navigation data and postoperative CT measurements suggests that postoperative CT scan alignment data should be interpreted with caution. A surgeon should consider a multitude of factors when analysing component and limb alignment postoperatively.
Canadian journal of surgery. Journal canadien de chirurgie, 2014
Few studies have compared the effect of different computer navigation systems on postoperative alignment in patients who have had total knee arthroplasty (TKA). We examined 2 computed tomography (CT)-free computer navigation systems by comparing the accuracy of intraoperative measurements to postoperative alignment. Patients underwent unilateral TKA performed by a single surgeon using 1 of 2 CT-free navigation systems. We compared final intraoperative tibial and femoral coronal angles and mechanical axis with the same angles measured on standing postoperative radiographs. Groups of 31 and 50 patients underwent TKA with the 2 systems, respectively. We noted a significant difference in the coronal tibial implant angle (1.29º ± 1.35º) and in the mechanical axis (1.59º ± 2.36º) for one navigation system (both p < 0.001), while only the coronal tibial implant angle showed a significant difference (1.17º ± 1.65º, p < 0.001) for the second system. The number of radiographic outliers ...
Maedica, 2018
The aim of this second part is to review the existing described methods for measuring postoperative total knee arthroplasty (TKA) alignment in sagital and axial plane as well as the existing literature regarding the axial plane evaluation with the use of computer tomography. Given that the most frequent mistakes when positioning the total knee arthroplasty components are made in the axial plane, it is necessary to know what are the limits of radiographic evaluation, for which CT scan is the most valuable tool in assessing the rotation of the components.
Alignment in total knee arthroplasty
The Journal of Bone and Joint Surgery, 2004
Restoration of neutral alignment of the leg is an important factor affecting the long-term results of total knee arthroplasty (TKA). Recent developments in computer-assisted surgery have focused on systems for improving TKA. In a prospective study two groups of 80 patients undergoing TKA had operations using either a computer-assisted navigation system or a conventional technique. Alignment of the leg and the orientation of components were determined on post-operative long-leg coronal and lateral films. The mechanical axis of the leg was significantly better in the computer-assisted group (96%, within ±3° varus/valgus) compared with the conventional group (78%, within ±3° varus/valgus). The coronal alignment of the femoral component was also more accurate in the computer-assisted group. Computer-assisted TKA gives a better correction of alignment of the leg and orientation of the components compared with the conventional technique. Potential benefits in the long-term outcome and fun...
Role of full length weight bearing radiograph in assessing the Alignment in Total Knee Arthroplasty
IOSR Journal of Dental and Medical Sciences, 2016
Various factors contribute to the decrease in the longevity of the total knee arthroplasty. Of these various factor, mal-alignment of the components and hence the axial alignment of limb is well within the control of the operating surgeon. The aim of the study is to compare the axial alignment of the lower extremity before and after surgery in patients undergoing total knee replacement by assessing the mechanical axis in the full length weight bearing radiograph taken preoperatively and post operatively. And to correlate the midterm results with reference to the mechanical axis. While in all the patients in the study group showed a statistically significant improvement between the preoperative and postoperative knee scores, the unfavorable group did not show any significant improvement in the knee scores. In midterm follow up we conclude that a strong correlation exists between the functional outcome and the axial alignment of the extremity postoperatively. And hence full length weight bearing radiograph is a valuable tool in determining the mechanical axis.
The Variability of Femoral Rotational Alignment in Total Knee Arthroplasty
The Journal of Bone and Joint Surgery (American), 2005
Background: Several reference axes are used to establish femoral rotational alignment during total knee arthroplasty, but debate continues with regard to which axis is most accurately and easily identified during surgery. Computerassisted navigation systems have been developed in an attempt to more accurately and consistently align implants during total knee arthroplasty, but it is unknown if navigation systems can improve the accuracy of femoral rotational alignment as compared with that achieved with more traditional techniques involving mechanical guides. The purposes of the present study were to characterize the variability associated with femoral rotational alignment techniques and to determine whether the use of a computer-assisted surgical navigation system reduced this variability.
International Journal of Orthopaedics Sciences, 2019
The main aim of this study is to radiologically assess the components alignment in various planes in total knee replacement and to assess its relationship to the functional outcome using the knee society score. Materials and Methods: This hospital based prospective observational study of 30 patients was conducted in the department of Orthopaedics at Maharaja Agrasen Hospital, New Delhi on patients who underwent elective primary Total Knee Arthroplasty and the period of study being 24 months from June 2016 to May 2018. All patients were assessed clinically and functionally using the Knee Society Score pre and post operatively for a follow up period of 6 months. Results: The mean coronal alignment and rotational alignment of femoral component in our study was 5.87 degrees and 2.99 degrees of external rotation respectively. The mean tibial component coronal and rotational alignment in our study was 90 degrees and 17.77 degrees respectively. The mean preoperative flexion of 81.33 degrees increased to 113.5 degrees postoperatively with a significant p value of <0.001. There was significant improvement of Knee Clinical Score and Knee Functional Score following Total Knee Arthroplasty with a p value <0.001. Conclusion: In our study the use of conventional extra medullary guide for tibia and intramedullary guide for femur to align a total knee replacement provided acceptable alignment and gives a good functional outcome as measured by knee society score.
The Journal of Bone and Joint Surgery (American), 2008
Background: Computer navigation systems generally establish the rotational alignment axis of the femoral component on the basis of user-defined anatomic landmarks. However, navigation systems can also record knee kinematics and average alignment axes established with multiple techniques. We hypothesized that establishing femoral rotational alignment with the use of kinematic techniques is more accurate and precise (repeatable) than the use of anatomic techniques and that establishing femoral rotational alignment by averaging the results of different alignment techniques is more accurate and precise than the use of a single technique.
The Journal of Arthroplasty, 2010
The best operative technique for achieving appropriate postoperative alignment following total knee arthroplasty (TKA) remains controversial, with proponents of extramedullary, intramedullary and computer-assisted techniques. One hundred ninety-two consecutive patients undergoing TKA were prospectively evaluated with full-length lower extremity radiographs. Patients underwent cemented TKA using femoral and tibial intramedullary instrumentation. Digital radiographs were analyzed using PACS (AGFA Healthcare, Ridgefield Park, NJ) software. Tibial component alignment was measured in the coronal and sagittal planes. Tibial component slope averaged 3.89°+ 1.96 for the cruciate-retaining components and averaged 1.7°+ 1.92 for PS components. The average coronal tibial component alignment was 90.00°, and 99% were within 3°o f neutral mechanical alignment with only 2 (1%) outliers. Intramedullary instrumentation resulted in excellent postoperative tibial component and lower extremity alignment.
Effect of Rotation and Knee Flexion on Radiographic Alignment in Total Knee Arthroplasties
Clinical Orthopaedics and Related Research, 1996
A synthetic femur and tibia were used to create a model resurfacing total knee arthroplasty. The femoral component was placed in 7" valgus; the tibial component was placed in 2" varus with a 5" posterior slope. The overall anatomic alignment was 5" valgus. A series of radiographs were taken on 14 inch x 17 inch plates, in full extension and 10" flexion, with the limb rotated, in 5" increments, from 20" external rotation to 25" internal rotation. Seven orthopaedic surgeons independently measured the tibiofemoral angle and tibial alignment for each series of radiographs; interobserver variability was insignificant. Average radiographic anatomic alignment ranged from 2.29' valgus in 20" external rotation and 10" flexion, to 6.73" valgus in 25" internal rotation and 10" flexion. Limb rotation and knee flexion of lo", either alone or in combination, had a highly statistically significant effect on measured values of the anatomic alignment. Tibia1 alignment ranged from 5" varus in 20" external rotation to 3" valgus in 25" internal rotation, with the knee flexed 10". The variability associated with changes in rotation was statisti-From the Arthritis Management Service,