Midflexion instability in revision total knee arthroplasty.
Midflexion instability is a new concept associated with revision total knee arthroplasty. It appears as rotational instability with combined external rotation and valgus stress in a knee flexed between 45 degrees and 90 degrees. Three main factors contribute to this instability: anterior medial collateral ligament attenuation, femoral-tibial articular geometry, and tibial post-femoral box geometry. Rotational stress should be included when assessing stability intraoperatively to identify those patients who may require additional constraint.
McPherson
Edward J
EJ
Los Angeles Orthopaedic Institute, Los Angeles, California, USA.
Cuckler
John
J
Lombardi
Adolph V
AV
D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D006801:Humans; D007593:Joint Instability / Q000175:diagnosis / Q000209:etiology* / Q000517:prevention & control*; D007720:Knee Prosthesis / Q000009:adverse effects*; D012086:Reoperation / Q000009:adverse effects