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 .
Patient-specific instrumentation does not shorten surgical time: a prospective, randomized trial.
The primary purpose of this prospect i ve , r and omized study was to determine if patient-specific instrumentation ( PSI ) for total knee arthroplasty ( TKA ) shortened surgical time . Secondarily the number of instrument trays and alignment were also compared to cases performed with traditional instrumentation ( TI ) .  Fifty-two cases ( 26 per group ) were r and omized and videotaped to measure the length of surgery , as well as each individual surgical step . Component alignment and mechanical axis was measured radiographically for each patient . Total surgical time was over 4 minutes shorter for patients in the TI group ( 57.4 minutes vs. 61.8 minutes ; P<0.01 ) . More instrument trays were used in the TI group ( 7.3 vs. 2.5 ; P<0.001 ) . There was no significant difference in mechanical alignment between groups on postoperative long alignment radiographs ( P=0.77 ) . In conclusion , PSI did not shorten surgical time or improve alignment compared with TI in this prospect i ve , r and omized trial , but did reduce the required number of trays
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 .