PURPOSE: Rotating hinge knee prostheses are known to provide inherent stability. Yoke fractures of the hinged tibial insert of modern generation rotating hinge devices are a matter of continued concern. The aim of this study was to describe incidence and management of yoke fracture of the LPS™ hinged tibial insert. METHODS: Retrospective data analysis of two institutions identified 40 patients with a LPS™ total knee arthroplasty. Implant survival and prosthetic complications was calculated according to Kaplan-Meier. RESULTS: Out of the group of 40 patients, four fractures of the metal yoke occurred in four cases (failure rate: 10%). Furthermore, a second fracture occurred in two patients. The overall revision-free prosthetic survival was 57% at 38 months, while prosthetic survival until yoke fracture was 86% at 38 months. CONCLUSION: Handling yoke fractures as mechanical complication includes replacing the hinged insert, stabilization of the joint and joint line height preservation in order to decrease the cantilever effect at the insert-base plate interface.
PURPOSE: Rotating hinge knee prostheses are known to provide inherent stability. Yoke fractures of the hinged tibial insert of modern generation rotating hinge devices are a matter of continued concern. The aim of this study was to describe incidence and management of yoke fracture of the LPS™ hinged tibial insert. METHODS: Retrospective data analysis of two institutions identified 40 patients with a LPS™ total knee arthroplasty. Implant survival and prosthetic complications was calculated according to Kaplan-Meier. RESULTS: Out of the group of 40 patients, four fractures of the metal yoke occurred in four cases (failure rate: 10%). Furthermore, a second fracture occurred in two patients. The overall revision-free prosthetic survival was 57% at 38 months, while prosthetic survival until yoke fracture was 86% at 38 months. CONCLUSION:Handling yoke fractures as mechanical complication includes replacing the hinged insert, stabilization of the joint and joint line height preservation in order to decrease the cantilever effect at the insert-base plate interface.
Authors: Eric R Henderson; John S Groundland; Elisa Pala; Jeremy A Dennis; Rebecca Wooten; David Cheong; Reinhard Windhager; Rainer I Kotz; Mario Mercuri; Philipp T Funovics; Francis J Hornicek; H Thomas Temple; Pietro Ruggieri; G Douglas Letson Journal: J Bone Joint Surg Am Date: 2011-03-02 Impact factor: 5.284
Authors: Jacob Bickels; James C Wittig; Yehuda Kollender; Robert M Henshaw; Kristen L Kellar-Graney; Issac Meller; Martin M Malawer Journal: Clin Orthop Relat Res Date: 2002-07 Impact factor: 4.176