We conclude that PSI does not improve the accuracy of alignment of the components in TKR compared with conventional instrumentation
Intra-operative results and radiological outcome of conventional and patient-specific surgery in total knee arthroplasty: a multicentre, randomised controlled trial
Purpose This prospect i ve , double-blind , r and omised controlled trial was design ed to address the following research questions : firstly , is there a significant difference in outliers in alignment in the frontal and sagittal plane between PSG TKA and conventional TKA . Secondly , is there a significant difference in operation time , blood loss and length of hospital stay between the two techniques . We hypothesise that there will be fewer outliers with PSG TKA and that operation time , blood loss and length of hospital stay can be significantly reduced with PSG . Methods A total of 180 patients were r and omised for PSG TKA ( group 1 ) or conventional TKA ( group 2 ) in two centres . Patients were stratified per hospital . Alignment of the mechanical axis of the leg and flexion/extension and varus/valgus of the individual prosthesis components were measured on digital , st and ing , long-leg and st and ard lateral radiographs by two independent outcome assessors in both centres . Percentages of outliers ( > 3 ° ) were determined . We compared blood loss , operation time and length of hospital stay . Results There was no statistically significant difference in mean mechanical axis or outliers in mechanical axis between groups . No statistically significant difference was found for the alignment of the individual components in the frontal plane nor for the percentages of outliers . There was a statistically significant difference in outliers for the femoral component in the sagittal plane , with a higher percentage of outliers in the group 1 ( p = 0.017 ) . No such significant result was found for the tibial component in that plane . All interclass correlation coefficients were good . Blood loss was 100 mL less in group 1 ( p < 0.001 ) . Operation time was 5 min shorter in group 1 ( p < 0.001 ) . Length of hospital stay was identical with a mean of 3.6 days ( p = 0.657 ) . Conclusions The results in terms of obtaining a neutral mechanical axis and a correct position of the prosthesis components did not differ between groups . A small reduction in operation time and blood loss was found with the PSG system . Future research should especially focus on cost-effectiveness analysis and functional outcome of PSG TKA.Level of evidence
We conclude that PSI does not improve the accuracy of alignment of the components in TKR compared with conventional instrumentation