Bertrand Boyer1, Barbara Bordini2, Dalila Caputo2, Thomas Neri3, Susanna Stea2, Aldo Toni2. 1. Laboratorio di Tecnologia Medica, Istituto Ortopedico Rizzoli, Via di Barbiano, 1/10, 40136 Bologna, Italy; Inserm, U1059, 42270 St-Étienne, France. Electronic address: bertrand.boyer@chu-st-etienne.fr. 2. Laboratorio di Tecnologia Medica, Istituto Ortopedico Rizzoli, Via di Barbiano, 1/10, 40136 Bologna, Italy. 3. LIBM, CHU de Saint-Étienne, 42055 St-Étienne, France.
Abstract
BACKGROUND: Bilateral cases, representing at least 25% of total knee arthroplasties (TKA), could convey a statistical bias linked to dependency. Registries allow exploring this issue, susceptible to question surgeon validated protocols. Do bilateral total knee arthroplasties behave differently than unilateral knees in terms of implant survival? HYPOTHESIS: Bilateral TKA have a better survival than unilateral TKA. PATIENTS AND METHODS: A number of 14,652 bilateral and 27,440 unilateral TKAs were compared. Influencing factors were tested with hazard ratios applied on bilateral knees. RESULTS: Bilateral knees had a better survival (p<0.001). Delay between first and second side surgeries had an influence on survival of the first knee: if below a year, the first knee survival was superior to the second knee; more than three years between both arthroplasties significantly decreased the survival of the first implant. If the first knee was revised, the hazard ratio for revision of the second implant was 3.5. DISCUSSION: Series should include separate evaluations of bilateral cases, because they have a better survival than unilateral knees. A long delay between both knee replacements could impact both implant survivals. Level of Evidence III, Cohort Comparative Study.
BACKGROUND: Bilateral cases, representing at least 25% of total knee arthroplasties (TKA), could convey a statistical bias linked to dependency. Registries allow exploring this issue, susceptible to question surgeon validated protocols. Do bilateral total knee arthroplasties behave differently than unilateral knees in terms of implant survival? HYPOTHESIS: Bilateral TKA have a better survival than unilateral TKA. PATIENTS AND METHODS: A number of 14,652 bilateral and 27,440 unilateral TKAs were compared. Influencing factors were tested with hazard ratios applied on bilateral knees. RESULTS: Bilateral knees had a better survival (p<0.001). Delay between first and second side surgeries had an influence on survival of the first knee: if below a year, the first knee survival was superior to the second knee; more than three years between both arthroplasties significantly decreased the survival of the first implant. If the first knee was revised, the hazard ratio for revision of the second implant was 3.5. DISCUSSION: Series should include separate evaluations of bilateral cases, because they have a better survival than unilateral knees. A long delay between both knee replacements could impact both implant survivals. Level of Evidence III, Cohort Comparative Study.
Authors: Abdullah O Bawazir; Hossein A Filimban; Nawaf Halabi; Salman W Bafageeh; Rayan Halabi; Saeed Albukhari; Eyad A Alakkas; Habib Al Etani; Abdullah Basalaim; Ahmed Alturkistan; Bander Hetaimish Journal: Saudi Med J Date: 2022-03 Impact factor: 1.422