Double-concave deformity of the polyethylene tibial post in posterior stabilized total knee arthroplasty

Yasuo Niki, Hideo Matsumoto, Fumihiro Yoshimine, Yoshiaki Toyama, Yasunori Suda, Scott A. Banks

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


This report describes a unique case of bilateral total knee arthroplasty necessitating revision of the polyethylene insert, which showed prominent marks on the tibial post resulting from repeated seiza-style sitting. The patient presented 7 years postoperatively with knee pain and flexion disturbance due to continuous joint effusion persisting for more than 4 months. Proliferating synovia throughout the joint revealed reactive synovitis to polyethylene particles. The retrieved polyethylene inserts displayed double-concave deformity of the tibial post with burnishing and creep in tibiofemoral articulation. The damage pattern of retrieved polyethylene inserts reflected the data from tibiofemoral contact location obtained using a shape-matching technique in the early postoperative phase. This case provides an example of damage to the polyethylene tibial post caused by a floor-sitting lifestyle and the potential clinical sequelae.

Original languageEnglish
Pages (from-to)497.e7-497.e10
JournalJournal of Arthroplasty
Issue number3
Publication statusPublished - 04-2010
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Orthopedics and Sports Medicine


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