title: Results of total knee replacement with a cruciate-retaining model for severe valgus deformity--a study of 48 patients followed for an average of 9 years.
abstract: The objectives of the present study were to find out the results and the factors affecting survival after primary knee arthroplasty with a cruciate-retaining prosthesis in severe valgus deformity. Forty-eight patients (52 knees) participated in the current follow-up study. All patients were followed at least 5 years or to first revision. Mean follow-up time was 9 years (range, 1 to 17 years).The Kaplan-Meier analysis revealed 79% (95% CI 68% to 91%) survival rate with revision for any reason and 81% (95% CI 70% to 93%) survival rate with revision for instability as an endpoint at 10 years. Preoperatively TFA was 23° (range, 15°-51°) in valgus and 7° (range, 21° valgus-4° varus) in valgus postoperatively. Of the 14 re-operated patients, eight were revised because of progressive postoperative medial collateral ligament instability. All re-operations were performed during the first 4 years of the follow-up. The mean TFA was 15.5° valgus postoperatively for those eight and the odds ratio for a revision was 2 (95% CI 1-3, p = 0.025) when compared to the rest of the study population. The residual valgus deformity increases the risk of re-operation and it should be avoided. If proper soft-tissue balance cannot be achieved or there is no functional medial collateral ligament present more constrained implants should be used. In selected cases where both bony correction and ligament balancing have properly been achieved the use of a cruciate-retaining type of prosthesis is justified.
authors.affiliation: ORTON Research Institute, ORTON Foundation, Helsinki, Finland. esakos@utu.fi
authors.forename: Esa
authors.initials: E
authors.lastname: Koskinen
authors.forename: Ville
authors.initials: V
authors.lastname: Remes
authors.forename: Pekka
authors.initials: P
authors.lastname: Paavolainen
authors.forename: Arsi
authors.initials: A
authors.lastname: Harilainen
authors.forename: Jerker
authors.initials: J
authors.lastname: Sandelin
authors.forename: Kaj
authors.initials: K
authors.lastname: Tallroth
authors.forename: Jyrki
authors.initials: J
authors.lastname: Kettunen
authors.forename: Pekka
authors.initials: P
authors.lastname: Ylinen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007593:Joint Instability / Q000000981:diagnostic imaging / Q000209:etiology / Q000601:surgery*; D007719:Knee Joint / Q000503:physiopathology / Q000601:surgery; D008297:Male; D017888:Medial Collateral Ligament, Knee / Q000601:surgery*; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D011859:Radiography; D016059:Range of Motion, Articular; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome