title: Development of a force amplitude- and location-sensing device designed to improve the ligament balancing procedure in TKA.
abstract: To improve the ligament balancing procedure during total knee arthroplasty a force-sensing device to intraoperatively measure knee joint forces and moments has been developed. It consists of two sensitive plates, one for each condyle, a tibial base plate and a set of spaces to adapt the device thickness to the patient-specific tibiofemoral gap. Each sensitive plate is equipped with three deformable bridges instrumented with thick-film piezoresistive sensors, which allow accurate measurements of the amplitude and location of the tibiofemoral contact forces. The net varus-valgus moment is then computed to characterize the ligamentous imbalance. The developed device has a measurement range of 0-500 N and an intrinsic accuracy of 0.5% full scale. Experimental trials on a plastic knee joint model and on a cadaver specimen demonstrated the proper function of the device in situ. The results obtained indicated that the novel force-sensing device has an appropriate range of measurement and a strong potential to offer useful quantitative information and effective assistance during the ligament balancing procedure in total knee arthroplasty.
authors.affiliation: M E Müller Research Center, University of Bern, 3014 Bern, Switzerland. denis.crottet@memcenter.unibe.ch
authors.forename: Denis
authors.initials: D
authors.lastname: Crottet
authors.forename: Thomas
authors.initials: T
authors.lastname: Maeder
authors.forename: Daniel
authors.initials: D
authors.lastname: Fritschy
authors.forename: Hannes
authors.initials: H
authors.lastname: Bleuler
authors.forename: Lutz P
authors.initials: LP
authors.lastname: Nolte
authors.forename: Ion P
authors.initials: IP
authors.lastname: Pappas
mesh_terms: D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation* / Q000379:methods; D002102:Cadaver; D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D066298:In Vitro Techniques; D007719:Knee Joint / Q000503:physiopathology* / Q000601:surgery*; D008022:Ligaments / Q000503:physiopathology* / Q000601:surgery*; D008954:Models, Biological; D017755:Prosthesis Fitting / Q000295:instrumentation* / Q000379:methods; D013314:Stress, Mechanical; D014160:Transducers, Pressure