title: Incidence, predictors, and effects of residual flexion contracture on clinical outcomes of total knee arthroplasty.
abstract: Patients who present with large flexion contracture (FC) but have well maintained maximum flexion tend to have a flexion-extension gap mismatch, which can cause residual FC or flexion instability after TKA. We routinely use posterior-stabilized implants, perform soft tissue balancing and additional distal femur resection, and determine the polyethylene insert thickness based on flexion-extension gap difference to avoid postoperative FC and flexion instability. We retrospectively reviewed 911 TKAs performed with this protocol to determine the incidence, predictors and effects of postoperative FC on clinical outcomes. Knees with postoperative FC ≥10° were identified, and their clinical outcomes were compared with knees without FC. The average follow-up period was 35months (range, 24-72months). Eighteen (2.0%) of the 911 knees presented with postoperative FC. The occurrence of postoperative FC was associated with preoperative FC and anterior knee pain, but not with a flexion-extension gap mismatch. A mild to moderate postoperative FC does not increase pain, but may be detrimental to quality of life.
authors.affiliation: Department of Orthopaedic Surgery, Uijeongbu St. Mary's Hospital, The Catholic University of Korea College of Medicine, Uijeongbu, Gyeonggi-do, Korea.
authors.forename: In Jun
authors.initials: IJ
authors.lastname: Koh
authors.forename: Chong Bum
authors.initials: CB
authors.lastname: Chang
authors.forename: Yeon Gwi
authors.initials: YG
authors.lastname: Kang
authors.forename: Sang Cheol
authors.initials: SC
authors.lastname: Seong
authors.forename: Tae Kyun
authors.initials: TK
authors.lastname: Kim
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee; D003286:Contracture / Q000453:epidemiology* / Q000209:etiology*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology* / Q000209:etiology*; D011379:Prognosis; D012189:Retrospective Studies; D016896:Treatment Outcome