There was a trend towards a protective effect  with PSCB for the risk of femoral component outliers , but the opposite was observed for the tibial component .
Conclusions This meta- analysis found no evidence that using patient-specific cutting blocks provides superior accuracy to using manual instrumentation during TKA
Purpose Because published studies on the accuracy achieved with patient-specific guides during total knee arthroplasty ( TKA ) contradict each other , this systematic review and meta- analysis sought to compare radiological TKA outcomes when patient-specific cutting blocks ( PSCB ) were used to the outcomes when st and ard manual instrumentation was used .
Contribution of patient-specific cutting guides to lower limb alignment for total knee arthroplasty.
UNLABELLED Patient-specific cutting guides ( PSCG ) are an extension of preoperative planning for total knee arthroplasty ( TKA ) . We wanted to evaluate their contribution to postoperative lower limb alignment . This study involved primary TKA cases being performed with PSCG between 10/05/2010 and 05/03/2013 and then followed prospect ively . The analysis involved the PSCG usage and postoperative measurement of the patient 's HKA , medial distal femoral joint angle ( MDFA ) and medial proximal tibia joint angle ( MPTA ) .  Of the 104 eligible cases , 68 were included ; 11 of these cases were not performed completely with the PSCG as initially planned . Thus we compared these 11 cases with the 57 where PSCG were used . The preoperative HKA in the included cases was 175.8 ° ± 7.8 ; the postoperative angles on average were 179.2 ° ± 2.9 for the HKA , 89.9 ° ± 1.6 for the MDFA and 89.0 ° ± 2.3 for the MPTA . The average postoperative deviation from the target values was 2.22 ° ± 2.14 for the HKA angle , 1.07 ° ± 1.15 for the MDFA and 1.66 ° ± 1.90 for the MPTA . There were no significant differences between the two groups in any of the measurements . The lower limb alignment goal was achieved in 50 cases ( 73 % ) , with 41 of these achieved with PSCG ( 82 % ) . Of the 18 cases where the target was not achieved , PSCG were used 16 times ( 88 % ) . In this study cohort , lower limb alignment was not significantly closer to an HKA of 180 ° or achieved more often with the use of PSCG versus st and ard instrumentation . Since the results of the two groups can be superimposed , we found no evidence that use of PSCG  improves postoperative lower limb alignment . LEVEL OF EVIDENCE IV . STUDY TYPE Cohort
There was a trend towards a protective effect  with PSCB for the risk of femoral component outliers , but the opposite was observed for the tibial component .
Conclusions This meta- analysis found no evidence that using patient-specific cutting blocks provides superior accuracy to using manual instrumentation during TKA
Purpose Because published studies on the accuracy achieved with patient-specific guides during total knee arthroplasty ( TKA ) contradict each other , this systematic review and meta- analysis sought to compare radiological TKA outcomes when patient-specific cutting blocks ( PSCB ) were used to the outcomes when st and ard manual instrumentation was used .