Agreement in component size between preoperative measurement, navigation and final implant in total knee replacement

Abstract

Summary Background One of the possible causes of dissatisfaction reported by many patients after total knee replacement (TKR) is the lack of agreement between component size and bone structure. To avoid this complication and facilitate the procedure, preoperative planning with digitized templates is recommended. Surgical navigation indicates the best position and the most adequate size of arthroplasty and may therefore replace preoperative radiographic measurement. The objective of the study was to check agreement between the sizes of TKR components measured before surgery with digitized templates, the size recommended by the navigation and sizes actually implanted. Methods In 103 patients scheduled for TKR, preoperative full-limb radiography was performed to measure the mechanical and anatomical axes of the limb, femur and tibia. The most adequate size of the femoral and tibial components was planned by superimposing digitized templates. The size recommended in navigation and the size of the finally implanted components were also recorded. Results A high level of agreement was found between the sizes of femoral and tibial components measured by X-rays and in navigation (0.750 and 0.772, respectively) (intraclass correlation and Cronbach's alpha). Agreement between the sizes recommended by X-rays and navigation and those finally implanted was 0.886 for the femur and 0.891 for the tibia. Agreement levels were not different in cases with prior deformities of limb axis. Conclusions The high level of agreement found in component sizes between radiographic measurement with digitized templates and navigation suggests that preoperative X-ray measurement is not needed when navigation is used for placement of implants during TKR. The translational potential of this article Computer-assisted surgery may avoid preoperative measurement with templates in TKR.

A computational tool for automatic selection of total knee replacement implant size using X-ray images

“…Comparing the results to those available in the literature for manual planning/templating, the size prediction accuracy of the tool was shown to be considerably better than the average reported across the 10 studies summarized by Hernández-Vaquero et al (2019) . This was also true when compared to studies that utilized CT data for manual templating ( Vaishya et al, 2018 ; Kobayashi et al, 2012 ).…”

“…Despite the importance of achieving a good fit, the accuracy of manual X-ray assessment and templating, for both femur components and tibia plates, can be poor. Hernández-Vaquero et al (2019) summarized the reported accuracies from 10 different studies and found mean selection accuracies of 59.2% for femur components and 60.7% for tibia plates. With ±1 size permitted, mean scores of 97.4% and 96.4% were recorded respectively.…”

Accuracy and clinical role of digital templating for total knee arthroplasty performed on haemophilic knees

“…In many studies that investigating the value and clinical role of preoperative templating, statistical modelling has assessed the success of the templated size in precisely matching the applied size, as well as the success of sizes one size larger and smaller than the templated size in matching the applied implant size. 5,11,16,30,31 While we also presented this data, it was not the primary focus of our statistical approach.…”

Artroplastía total de rodilla bilateral en un tiempo quirúrgico asistida por computadora

“…El resultado del eje mecánico obtenido en nuestros pacientes coincide con los resultados de varios metaanálisis, 14 proponiendo esta técnica de elección en deformidades en varo o valgo mayores de 10 o para aumentar la precisión del eje mecánico final y el posicionamiento de los componentes protésicos de tibia y fémur. 15,16 En nuestro estudio no incluimos los valores preoperatorios del eje mecánico para hacer una comparación objetiva, sólo pudimos comprobar que al utilizar esta técnica existen mejorías significativas tanto en funcionalidad, dolor y alineación del eje mecánico a mediano y largo plazo. Consideramos la necesidad de seguir a los pacientes por un período más largo para poder emitir resultados a largo plazo.…”