TITLE:
Patient-specific instruments as a standard procedure in total knee arthroplasty: Logistics and postoperative radiological results in 70 patients
AUTHORS:
Dominik Drnek, Nicolas Haffner, Armin Sadjed, Peter Ritschl
KEYWORDS:
Patient-Matched Instrumentation; Patient-Matched Cutting Blocks; Total Knee Arthroplasty; Radiological Results
JOURNAL NAME:
Case Reports in Clinical Medicine,
Vol.3 No.1,
January
21,
2014
ABSTRACT: Serous
Purpose: There is limited information in the literature surrounding the use of
patient-specific instrumentation (PSI) by a large number of surgeons. This
prospective observational study was therefore designed to evaluate the
logistics of using PSI for total knee arthroplasty (TKA) in a multi-surgeon
environment, as well as its accuracy in positioning components. Methods: Of
73 patients enrolled in this study, 3 were excluded after the surgeon decided
intraoperatively to switch to conventional instrumentation. Results: Mean
operative time was 77.6 minutes. The component size had to be changed in 19
patients and bone cuts corrected in 12. In 65 of the 70 cases (92.9%),
mechanical alignment was within the optimal range from 3° varus to 3° valgus,
with the remaining 5 cases considered outliers (7.1%). Mean overall mechanical
alignment was 0.3° varus (standard deviation, ±2°). There was a distinct
variance with regard to the position of the tibial component in the sagittal
plane. Conclusions: PSI can be effectively incorporated in larger, multisurgeon
practices. Although high accuracy was observed for overall mechanical
alignment and component positioning in the frontal and sagittal planes, further
attention must be paid to the tibial slope. We highly recommend the use of the
extramedullary alignment rod to the proper position of the tibial block, as
well as double-checking the slope before performing bone cuts.