Comparative Incidence of Patellofemoral Complications Between 2 Total Knee Arthroplasty Systems in a Multicenter, Prospective Clinical Study

J Arthroplasty. 2017 Sep;32(9S):S187-S192. doi: 10.1016/j.arth.2017.04.014. Epub 2017 Apr 20.


Background: Cumulative incidence rates (CIRs) of patellofemoral complications (PCCs) and patellofemoral symptomatic crepitus (SC) using a new knee system-total knee arthroplasty (NEW-TKA) were compared with those of a currently available product-total knee arthroplasty (CA-TKA).

Methods: Twenty-two investigators prospectively enrolled 704 patients into a study using CA-TKA; 364 received a posterior-stabilized configuration. Twenty-three investigators (19 from the CA-TKA study) enrolled 1138 patients with NEW-TKA; 584 received a posterior-stabilized configuration. CIRs were estimated with Kaplan-Meier methods.

Results: CA-TKA had 32 PCCs (6.15% CIR at 1 year and 8.26% at 2 years). NEW-TKA had 19 PCCs (3.15% CIR at 1 year and 4.11% at 2 years). CA-TKA had 15 SCs, 12 before 2 years (CIR = 3.67%); NEW-TKA had 5 SCs before 2 years (CIR = 1.21%). NEW-TKA had a statistically lower CIR of overall PCC and SC (log-rank P values = .018 for PCC and .017 for SC).

Conclusion: Interim 1- and 2-year CIRs of PCC and SC in NEW-TKA were less than half of those for CA-TKA, which is a promising trend for this new implant.

Keywords: complication; pain; patellofemoral complications; patellofemoral crepitus; symptomatic crepitus; total knee arthroplasty.

Publication types

  • Comparative Study
  • Multicenter Study

MeSH terms

  • Aged
  • Arthroplasty, Replacement, Knee / methods*
  • Female
  • Femur / surgery
  • Humans
  • Incidence
  • International Cooperation
  • Kaplan-Meier Estimate
  • Knee Joint / surgery
  • Male
  • Middle Aged
  • Patella / surgery
  • Postoperative Complications / epidemiology*
  • Prospective Studies
  • Treatment Outcome