Piraino D, Richmond B, Freed H, Belhobek G, Schils J, Stulberg B
Department of Radiology, Cleveland Clinic Foundation, OH 44195-5021.
AJR Am J Roentgenol. 1990 Sep;155(3):555-8. doi: 10.2214/ajr.155.3.2117356.
One technique for replacing the articular surface of the patella in total knee replacement is the use of a cementless porous-coated metal-backed polyethylene component. Anteroposterior, lateral, and Merchant or skyline radiographs in 10 cases of porous-coated metal-backed components that failed were evaluated for component alignment, component displacement, radiolucencies, loose beads, and integrity of the patellar component. Component failure was documented by surgery in all 10 cases. Seven cases of failure involved the patellar pegs or junction of the pegs with the metal backing and three cases involved the polyethylene portion. In the seven cases of peg-metal backing failure, three cases showed loose beads before failure and seven cases showed displacement of the metal backing at time of failure. All three cases of polyethylene failure showed narrowing or displacement of the polyethylene portion. Our experience shows that displacement of the metal backing, displacement of the polyethylene, and disruption of patellar pegs are seen in failed porous-coated metal-backed patellar components. Loose beads may be seen before peg-metal backing failure.
全膝关节置换术中一种用于置换髌骨关节面的技术是使用无骨水泥多孔涂层金属背衬聚乙烯组件。对10例多孔涂层金属背衬组件失败病例的前后位、侧位以及Merchant位或髌股关节切线位X线片进行评估，观察组件的对线情况、组件移位、透亮线、松动的珠子以及髌骨组件的完整性。所有10例病例均通过手术记录了组件失败情况。7例失败涉及髌骨固定钉或固定钉与金属背衬的连接处，3例涉及聚乙烯部分。在7例固定钉-金属背衬失败的病例中，3例在失败前出现了松动的珠子，7例在失败时出现了金属背衬移位。3例聚乙烯失败的病例均显示聚乙烯部分变窄或移位。我们的经验表明，在失败的多孔涂层金属背衬髌骨组件中可见金属背衬移位、聚乙烯移位以及髌骨固定钉断裂。在固定钉-金属背衬失败前可能会出现松动的珠子。
