Survivorship analysis and results of total condylar knee arthroplasty. Eight- to 11-year follow-up period.

This study deals with survivorship of total condylar knee arthroplasties in 87 consecutive patients (112 knees) with follow-up periods of up to 11 years. The end point of the survivorship was defined as: (1) the need for revision due to septic or aseptic loosening; (2) roentgenographic loosening evidenced by a shift of component position; or (3) radiolucency extending under the condyle of the tibial component and partially along the peg, when associated with clinical symptoms. Life table calculations predict 88.7% survivorship of total condylar knee arthroplasty. Using revision for septic or aseptic loosening and recommendation for surgery as an end point, the survivorship was 94.1% 11 years after operation in this series. Seventy-two patients (90 knees) of 87 were available for clinical and roentgenographic study at eight to 11 years. Eight patients (12 knees) had died and seven patients (ten knees) were lost to follow-up study. The results were excellent to good in 93%, fair in 3%, and poor in 4%. Roentgenographic evaluation revealed well-fixed components in 36 knees (40%). Radiolucencies of varying degrees were present in 54 knees (60%). Of the 54 knees, seven had radiolucency under the tibial condyle in Zones I-IV and partially along the peg in Zones V and VI. Two knees had component loosening, one with a loose patella and the other a loose tibial component; both of these patients were symptomatic. Variables such as the patient's age, sex, diagnosis, alignment and position of the prosthesis, and level of bone cut did not correlate with the development of radiolucencies at the cement-bone interface.(ABSTRACT TRUNCATED AT 250 WORDS)