Polyethylene failure of the patellar component in New Jersey low-contact stress total knee arthroplasties.
In a postoperative 5- to 12-year follow-up study of 598 New Jersey low-contact stress total knee arthroplasties, 32 required revision. All retrieved patellar components were examined for polyethylene damage. These 32 cases had 3 types of failure: split rupture (7 cases), peripheral wear (21), and cantilevering breakage (4), respectively 75%, 64.3%, and 100% of which showed subluxation and/or tilting of the patellar component on the prerevision roentgenograms. Misalignment at the joint contact surfaces and rotational blockage of the mobile patellar component were considered the major causes of the failure. A design of a flatter metallic button (giving larger focal thickness of the polyethylene) and a dome-shaped polyethylene (reducing stress concentration at the pinnacle) may alleviate the failure driving mechanism should subluxation or tilting of the patellar component take place.
Huang
Chun-Hsiung
CH
Department of Orthopaedic Surgery, Mackay Memorial Hospital, Taipei, Taiwan.
Liau
Jiann-Jong
JJ
Ho
Fang-Yuan
FY
Lin
Chia-Yin
CY
Young
Tai-Horng
TH
Cheng
Cheng-Kung
CK
D019645:Arthroplasty, Replacement, Knee; D005500:Follow-Up Studies; D006801:Humans; D007720:Knee Prosthesis; D010329:Patella; D020959:Polyethylene; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012086:Reoperation
D020959:Polyethylene