Mid-Flexion Instability After Total Knee Arthroplasty: Diagnosis, Implant Design, and Outcomes

Orthopedics. 2023 Jan-Feb;46(1):e13-e19. doi: 10.3928/01477447-20220719-01. Epub 2022 Jul 25.

Abstract

Mid-flexion instability (MFI) in total knee arthroplasty refers to a distinct clinical entity where the knee is stable at full extension and 90° of flexion, but unstable somewhere between these 2 points. The presentation of MFI is often vague, and studies defining objective clinical or intraoperative measurements are limited. In this review, we aim to properly define the condition, describe diagnostic criteria and risk factors contributing to MFI, review current implant design, and present outcomes of revision surgery performed for MFI. [Orthopedics. 2023;46(1):e13-e19.].

Publication types

  • Review

MeSH terms

  • Arthroplasty, Replacement, Knee* / adverse effects
  • Humans
  • Joint Instability* / diagnosis
  • Joint Instability* / etiology
  • Joint Instability* / surgery
  • Knee Joint / surgery
  • Knee Prosthesis* / adverse effects
  • Range of Motion, Articular
  • Reoperation / adverse effects