人工关节松动后的组织学观察

Histological Findings After Loosening of TotalHip Arthroplasty

将再次行人工关节置换术的２４例患者分为人工关节松动组（Ｌ组，１５例）和非松动组（ＮＬ组，９例）。术中取组织标本行组织学观察，并与家兔膝关节内注入的多聚甲基丙烯酸树脂（ＰＭＭＡ，Ｐ组）和高密度聚乙烯粉末（ＨＤＰ，Ｈ组）引起的组织学反应进行比较。临床Ｌ组与动物实验Ｐ组的组织学表现极为相似，巨噬细胞和泡沫细胞的浸润十分明显；而ＮＬ组虽然炎性反应轻，但可见组织变世和坏死，尤以假体远端的组织为甚，提示：ＰＭＭＡ及其与骨水泥单体混合后产生的热效应及骨水泥单体的毒性和腐蚀作用，可能是导致骨折和人工关节松动的主要因素。

Abstract Tweenty five revised joint replacements were clas-sified as loosening group(15 cases)and non-looseninggroup(10 cases).The periprosthetic tissue specimenswere taken during operation for histological investiga-tions, and compared with the histological reaction in-duced by polymethyl methacrylate (PMMA,P group)and high density polyethylene (HDP,H group )thathad been injected into the rabbit knee joint.The histo-logical appearances in loosening group were very simi-lar to those in P group,which showed that the inva-sion of macrophages and foam cell s were evident. Al-though the histological reaction in non-loosening groupwas mild, the degeneration and necrosis of theperiprosthetic tissues could be seen , especially at theextremity of femoral prosthesis, It revealed thatPMMA might be the main factor causing histologicalreaction and the heat effect, cytotoxicity and corrosionafter mixing PMMA with bone cement monomer mightbe one of factors inducing fracture and loosening ofprosthesis.