In-vivo alignment comparing patient specific instrumentation with both conventional and computer assisted surgery (CAS) instrumentation in total knee arthroplasty

J Arthroplasty. 2014 Feb;29(2):343-7. doi: 10.1016/j.arth.2013.06.029. Epub 2013 Aug 29.


Patient specific instrumentation (PSI) was developed to increase total knee arthroplasty (TKA) accuracy and efficiency. The study purpose was to compare immediate post-operative mechanical alignment, achieved using PSI, with conventional and computer assisted surgery (CAS) instruments in high volume TKA practices. This prospective, multicenter, non-randomized study accrued 66 TKA patients using PSI. A computed tomography (CT) based algorithm was used to develop the surgical plan. Sixty-two percent were females, 99% were diagnosed with osteoarthritis, average age at surgery was 66 years, and 33 was the average body mass index. A historical control group was utilized that underwent TKA using conventional instruments (n=86) or CAS (n=81), by the same set of surgeons. Postoperative mechanical alignment was comparable across the groups. Operative time mean and variance were significant.

Keywords: customized cutting blocks; customized patient instrumentation patient specific; instrumentation; mechanical alignment; surgical time; total knee arthroplasty.

Publication types

  • Comparative Study
  • Multicenter Study

MeSH terms

  • Aged
  • Arthroplasty, Replacement, Knee / instrumentation*
  • Bone Malalignment / prevention & control*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Osteoarthritis, Knee / surgery
  • Prospective Studies
  • Surgery, Computer-Assisted
  • Time Factors