The distribution of implant fixation for femoral components of TKA: a postmortem retrieval study.
Aseptic loosening of total knee arthroplasty (TKA) components is the foremost cause of implant failure in the long term. While tibial component loosening is of primary concern, femoral loosening may become a clinical problem due to younger, more active patients seeking TKA, and also high-flexion designs. In this study, we analyzed the fixation for 19 non-revised, postmortem retrieved, femoral components of TKA with time in service ranging from 1 to 22 years. We found that the average total contact fraction for cemented components was 9.5% and had a power law response (decrease) with years in service. The average initial interdigitation depth was 0.7mm, and the average current interdigitation depth was 0.13mm. Loss of interdigitation was 81%. Over all, minimal fixation seems necessary for long-term success of TKA femoral components.
Department of Orthopaedic Surgery, SUNY Upstate Medical University, Syracuse, New York.
Karen I
KI
Howard
Department of Orthopaedic Surgery, SUNY Upstate Medical University, Syracuse, New York.
Mark A
MA
Miller
Department of Orthopaedic Surgery, SUNY Upstate Medical University, Syracuse, New York.
Timothy A
TA
Damron
Department of Orthopaedic Surgery, SUNY Upstate Medical University, Syracuse, New York.
Kenneth A
KA
Mann
D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects* / Q000379:methods*; D001843:Bone Cements / Q000627:therapeutic use; D002102:Cadaver; D005260:Female; D005269:Femur / Q000601:surgery*; D006801:Humans; D007720:Knee Prosthesis / Q000009:adverse effects*; D008297:Male; D008670:Metals; D008875:Middle Aged; D016348:Osseointegration; D011474:Prosthesis Design; D011475:Prosthesis Failure / Q000209:etiology*; D016059:Range of Motion, Articular; D013977:Tibia / Q000601:surgery
D001843:Bone Cements; D008670:Metals
aseptic loosening; cementation; fixation; interdigitation depth; total knee arthroplasty