Hand MP Joint Implant Arthroplasty: The State of the Art. Vantages and Disadvantages of the Most Common Implant Arthroplasties

Abstract

The Authors on the ground of their personnel experience and of most recent literature data, review and analyze indications, advantages, disadvantages and limits of the most used metallic hinged prosthesis, cemented and semiconstrained prosthesis, and plastic interposition devices for MP joint restoration: in particular cemented and semiconstrained implants, even if show an acceptable clinical performance, generally assuring a painfree, stable functional range of motion, present the great problem of durability and salvageability linked to the rigidity of the implant and to the use of cement. Bone absorption and matherial breakdown often negate at long term follow-up many of the early good results obtained, so that these implants are preferably used in older patients. The method of Swanson silicone arthroplasty since 20 years assures long documented maintainance of functional results, not high incidence of complications and essential salvageability. However this method, either in our or in other Authors experience has shown a not very good clinical performance due to the limited average range of motion in flex/ext. and to a not infrequent tendence to rotation and subdislocation which are only minimally limited by the grommets use’s artifice. A promising step towards an ideal prosthesis which should be painfree, mobile, stable, durable, salvageable and of technical facility could be obtained with alumina or hydrossiapatitis implant matherial, fixed by tissue ingrowth system, or by a bioceramic resurfacing of the actually “well-functioning” devices to avoid problems of bone intolerance.