We did not find any differences between PSI and SI with respect to any other parameters .
Conclusions PSI  has advantages in axial alignment of the femoral component , operative time , and perioperative blood loss relative to SI .
No significant differences were found between PSI and SI with respect to alignment of the remaining components , number of outliers , or length of hospital stay .
Purpose The purpose of the present study was to compare patient-specific instrumentation ( PSI ) with st and ard instrumentation ( SI ) in patients undergoing total knee arthroplasty ( TKA ) .
PSI is hypothesized to have advantages with respect to component alignment ; number of outliers ( defined as alignment > 3 ° from the target alignment ) ; operative time ; perioperative blood loss ; and length of hospital stay .
This new surgical technique is expected to exhibit superior performance .
Patient-Specific CT-Based Instrumentation versus Conventional Instrumentation in Total Knee Arthroplasty: A Prospective Randomized Controlled Study on Clinical Outcomes and In-Hospital Data
Total knee arthroplasty ( TKA ) is a frequently performed procedure in orthopaedic surgery . Recently , patient-specific instrumentation was introduced to facilitate correct positioning of implants . The aim of this study was to compare the early clinical results of TKA performed with patient-specific CT-based instrumentation and conventional technique . A prospect i ve , r and omized controlled trial on 112 patients was performed between January 2011 and December 2011 . A group of 112 patients who met the inclusion and exclusion criteria were enrolled in this study and r and omly assigned to an experimental or control group . The experimental group comprised 52 patients who received the Signature CT-based implant positioning system , and the control group consisted of 60 patients with conventional instrumentation .  Clinical outcomes were evaluated with the KSS scale , WOMAC scale , and VAS scales to assess knee pain severity and patient satisfaction with the surgery . Specified in-hospital data were recorded . Patients were followed up for 12 months . At one year after surgery , there were no statistically significant differences between groups with respect to clinical outcomes and in-hospital data , including operative time , blood loss , hospital length of stay , intraoperative observations , and postoperative complications . Further high- quality investigations of various patient-specific systems and longer follow-up may be helpful in assessing their utility for TKA
We did not find any differences between PSI and SI with respect to any other parameters .
Conclusions PSI  has advantages in axial alignment of the femoral component , operative time , and perioperative blood loss relative to SI .
No significant differences were found between PSI and SI with respect to alignment of the remaining components , number of outliers , or length of hospital stay .
Purpose The purpose of the present study was to compare patient-specific instrumentation ( PSI ) with st and ard instrumentation ( SI ) in patients undergoing total knee arthroplasty ( TKA ) .
PSI is hypothesized to have advantages with respect to component alignment ; number of outliers ( defined as alignment > 3 ° from the target alignment ) ; operative time ; perioperative blood loss ; and length of hospital stay .
This new surgical technique is expected to exhibit superior performance .