Hinge Implants

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 (Jones, Clin Orthop Relat Res 94:50–57, 1973). 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 (Jones, Clin Orthop Relat Res 94:50–57, 1973). 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 (Habermann et al., Clin Orthop Relat Res 94:72–84, 1973). Like soft tissue arthroplasty, the clinical results of early, hinged prosthesis were poor. Prosthetic loosening, fracture, and deep infection were common (Jones, Clin Orthop Relat Res 94:50–57, 1973; Habermann et al., Clin Orthop Relat Res 94:72–84, 1973; Jackson and Elson, Clin Orthop Relat Res 94:104–114, 1973; Freeman, Clin Orthopaed Relat Res 94:85–91, 1973; Bain, Clin Orthop Relat Res 94:65–71, 1973; Wilson et al., J Bone Joint Surg Am 62(4):497–503, 1980; Hui and Fitzgerald, J Bone Joint Surg Am 62(4):513–519, 1980; Arden, Clin Orthop Relat Res 94:92–103, 1973; Shiers, J Bone Joint Surg 36-B(4):553–560, 1954; Shiers, Rheumatism 1961(17):54–60, 1961; Phillips, Clin Orthop Relat Res 94:122–127, 1973; Brady and Garber, J Bone Joint Surg Am 56(8):1610–1614, 1974; Lettin et al., J Bone Joint Surg 60-B(3):327–332, 1978; Karpinski and Grimer, Clin Orthop Relat Res 220:185–191, 1987; Jones et al., Clin Orthop Relat Res 140:145–152, 1979; leNobel and Patterson, J Bone Joint Surg 63-B(2):257–260, 1981; Bargar et al., J Bone Joint Surg Am 62(4):504–512, 1980). 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 have 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 combined with the use of porous metal cones holds promise for improved survivorship in complex knee reconstruction.