The EKA Femoral Rotation Focus Group has not identified a single best reference method to determine femoral component rotation , but surgeons mostly prefer the measured resection technique using at least two l and marks for cross-checking the rotation .
Malrotation of the femoral component after primary total knee arthroplasty ( TKA ) is one of the most important problems leading to painful TKA requiring revision surgery .
A comprehensive systematic review of the literature was performed to present current evidence on how to optimally place the femoral component in TKA .
Coronal femoral TKA position significantly influences in vivo patellar loading in unresurfaced patellae after primary total knee arthroplasty
Purpose As patellar tracking and loading is influenced by tibial tuberosity and trochlear groove ( TT – TG ) distance , patellar height , thickness and tilt as well as TKA component position , it was our hypothesis that these parameters significantly correlate with patellar BTU intensity and localization in SPECT/CT . The purpose of the study was to investigate whether TKA component position as well as the height , thickness and tilt of the unresurfaced patella influences the intensity and the distribution pattern of BTU in SPECT/CT . Methods A total of 62 consecutive patients who underwent primary TKA without patellar resurfacing were prospect ively included . Demographic data such as age , gender , side and type of primary TKA were noted . All patients underwent clinical and radiological examination  in a specialized knee clinic , including st and ardized radiographs ( anterior – posterior and lateral weight bearing , patellar skyline view ) and Tc-99m-HDP-SPECT/CT before , 12 and 24 months after TKA . SPECT/CT images were analysed on 3D reconstructed images . Rotational , sagittal and coronal position of the tibial and femoral TKA components was assessed using a previously vali date d analysis software . Measurements of BTU including intensity and anatomical distribution pattern were also performed from 3D data . The patellar height , thickness and tilt were measured , and the distance between TT and TG was measured using axial CT images . Univariate analysis was performed to identify any correlations between BTU and TKA component position and patellar measurements ( p < 0.05 ) . Results The highest median BTU was measured in the superior posterior parts of the patella . A statistically significant correlation was found between valgus alignment of the femoral TKA and increased BTU at the lateral patellar regions ( p < 0.05 ) . External rotation of the tibial TKA correlated with increased BTU at the lateral superior joint adjacent part ( p < 0.05 ) . No correlation was found between the tibial TKA  position ( varus – valgus , anterior and posterior slope ) , TT – TG distance , patellar height and patellar BTU values . Conclusions A significant correlation of increased patellar BTU was found with femoral valgus TKA alignment . These findings highlight the importance of femoral TKA position in coronal plane with regard to post-operative patellar tracking . Moreover , these facts might explain anterior knee pain in unhappy TKA with femoral valgus alignment . Level of evidence Diagnostic study , Level II
The EKA Femoral Rotation Focus Group has not identified a single best reference method to determine femoral component rotation , but surgeons mostly prefer the measured resection technique using at least two l and marks for cross-checking the rotation .
Malrotation of the femoral component after primary total knee arthroplasty ( TKA ) is one of the most important problems leading to painful TKA requiring revision surgery .
A comprehensive systematic review of the literature was performed to present current evidence on how to optimally place the femoral component in TKA .