Hinge implants

Abstract

The origin of knee arthroplasty can be traced to 1863 and Vernuil's attempt to relieve arthritic knee pain through the surgical interposition of joint capsule.1 Soft tissue substrates such as muscle, fat, fascia, and pig bladder were later used. However, the outcomes of each were equally as unsatisfactory as Vernuil's original procedure. Eventually biologic or tissue arthroplasty substrates were abandoned in favor of acrylics and metal alloys in the form of a hinge.1 The constraint to motion inherent in the hinge design was thought necessary to allow a stable physiologic range of motion and prevent dislocation of the prosthetic joint.2 Like soft tissue arthroplasty, the clinical results of early, hinged prosthesis were poor. Prosthetic loosening, fracture, and deep infection were common.1-17 Newer generations of the hinge design were developed to combat perceived design flaws but met with little success. Continued poor results led to disfavor of the hinge design, and the adoption of newer, more successful, unlinked arthroplasty designs. As total knee arthroplasty has expanded, specific indications for both an unconstrained and a highly constrained arthroplasty design have become apparent, and the development and evolution of the linked hinge prosthesis has continued. Further design modifications include multiple sizing, component modularity, hinge rotation, ingrowth surfaces, polyethylene bearings, and the manufacture of fracture-resistant superalloys. The resultant generation of linked, rotating, hinged prostheses holds promise for improved survivorship in complex knee reconstruction. © 2005 Springer Science+Business Media, Inc. All rights reserved.