Advantage of minimal anterior knee pain and long-term survivorship of cemented single radius posterior-stabilized total knee arthroplasty without patella resurfacing.
BACKGROUND
The single radius total knee prosthesis was introduced with the advantage of reduced patellar symptoms; however, there is no long-term follow-up study of the same. The purpose of this study was to determine the survival rate of single radius posterior-stabilized total knee arthroplasty and patellofemoral complication rates in a consecutive series.


METHODS
Seventy-one patients (103 knees) who underwent arthroplasty without patellar resurfacing using a single radius posterior-stabilized total knee prosthesis were followed up for a minimum 10 years. Clinical evaluation using Knee Society knee and function scores and radiologic evaluation were performed at regular intervals. Anterior knee pain as well as patellofemoral complications were evaluated with a simple questionnaire. The Kaplan-Meier product-limit method was used to estimate survival.


RESULTS
Seventeen patients (23 knees) were excluded due to death (12 knees) or lost to follow-up (11 knees). Of the 80 knees enrolled, all femoral components and 78 tibial components were well fixed without loosening at final follow-up. Two revisions were performed because of tibial component loosening and periprosthetic joint infection. One patient with tibial component loosening refused to have revision surgery. No obvious tibial insert polyethylene wear was observed. The survivorships at 132 months were 96.7% using revision or pending revision as end points. Anterior knee pain was present in 6 patients (6 knees, 7.5%) at the latest follow-up. No patellofemoral complication requiring revision was encountered.


CONCLUSIONS
The single radius posterior-stabilized total knee prosthesis demonstrated an excellent minimum 10-year survivorship. The low rates of implant loosening and 7.5% of anterior knee pain as a patellofemoral complication are comparable with those reported for other modern total knee prosthesis.
Department of Orthopedic Surgery, Ajou University Medical Center, Seoul, Korea.
Hyung-Min
HM
Ji
Department of Orthopaedic Surgery, Chung-Ang University College of Medicine, Seoul, Korea.
Yong-Chan
YC
Ha
Department of Orthopaedic Surgery, Chung-Ang University College of Medicine, Seoul, Korea.
Ji-Hoon
JH
Baek
Department of Orthopaedic Surgery, Chung-Ang University College of Medicine, Seoul, Korea.
Young-Bong
YB
Ko
D000368:Aged; D018771:Arthralgia / Q000601:surgery*; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation* / Q000379:methods*; D002484:Cementation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000601:surgery*; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D010329:Patella / Q000601:surgery; D011475:Prosthesis Failure; D012189:Retrospective Studies; D016896:Treatment Outcome
Arthroplasty; Knee; Replacement; Single-radius; Survival rate