We found that there was no significant benefit from using PS instrumentation in primary knee arthroplasty to aid in the positioning of either the tibial or femoral components .
Furthermore sagittal plane tibial component positioning was worse in the PS than the traditional ST group .
Our results suggest that at present PS instrumentation is not superior to ST instrumentation in primary total knee arthroplasty .
OBJECTIVE The aim of this study was to review the radiological alignment outcomes of patient Specific ( PS ) cutting blocks and St and ard Instrumentation in Primary Total Knee Arthroplasty .
METHODS We hypothesized that the use of PS techniques would significantly improve sagittal , coronal and rotational alignment of the prosthesis on short term .
Patient-specific Guides Do Not Improve Accuracy in Total Knee Arthroplasty: A Prospective Randomized Controlled Trial
Background Recently , patient-specific guides ( PSGs ) have been introduced , cl aim ing a significant improvement in accuracy and reproducibility of component positioning in TKA . Despite intensive marketing by the manufacturers , this cl aim has not yet been confirmed in a controlled prospect i ve trial . Questions / purpose sWe ( 1 ) compared three-planar component alignment and overall coronal mechanical alignment between PSG and conventional instrumentation and ( 2 ) logged the need for applying changes in the suggested position of the PSG . Methods In this r and omized controlled trial , we enrolled 128 patients . In the PSG cohort , surgical navigation was used as an intraoperative control . When the suggested cut deviated more than 3 ° from target , the use of PSG was ab and oned and marked as an outlier . When cranial-caudal position or size was adapted , the PSG was marked as modified . All patients underwent long-leg st and ing radiography and CT scan .  Deviation of more than 3 ° from the target in any plane was defined as an outlier . Results The PSG and conventional cohorts showed similar numbers of outliers in overall coronal alignment ( 25 % versus 28 % ; p = 0.69 ) , femoral coronal alignment ( 7 % versus 14 % ) ( p = 0.24 ) , and femoral axial alignment ( 23 % versus 17 % ; p = 0.50 ) . There were more outliers in tibial coronal ( 15 % versus 3 % ; p = 0.03 ) and sagittal 21 % versus 3 % ; p = 0.002 ) alignment in the PSG group than in the conventional group . PSGs were ab and oned in 14 patients ( 22 % ) and modified in 18 ( 28 % ) . Conclusions PSGs do not improve accuracy in TKA and , in our experience , were somewhat impractical in that the procedure needed to be either modified or ab and oned with some frequency . Level of Evidence Level I , therapeutic study . See instructions for authors for a complete description of levels of evidence
We found that there was no significant benefit from using PS instrumentation in primary knee arthroplasty to aid in the positioning of either the tibial or femoral components .
Furthermore sagittal plane tibial component positioning was worse in the PS than the traditional ST group .
Our results suggest that at present PS instrumentation is not superior to ST instrumentation in primary total knee arthroplasty .
OBJECTIVE The aim of this study was to review the radiological alignment outcomes of patient Specific ( PS ) cutting blocks and St and ard Instrumentation in Primary Total Knee Arthroplasty .
METHODS We hypothesized that the use of PS techniques would significantly improve sagittal , coronal and rotational alignment of the prosthesis on short term .