title: Calculating the Position of the Joint Line of the Knee Using Anatomical Landmarks.
abstract: Restoration of the joint line of the knee during primary and revision total knee arthroplasty is a step that directly influences patient outcomes. In revision total knee arthroplasty, necessary bony landmarks may be missing or obscured, so there remains a lack of consensus on how to accurately identify and restore the joint line of the knee. In this study, 50 magnetic resonance images of normal knees were analyzed to determine a quantitative relationship between the joint line of the knee and 6 bony landmarks: medial and lateral femoral epicondyles, medial and lateral femoral metaphyseal flares, tibial tubercle, and proximal tibio-fibular joint. Wide variability was found in the absolute distance from each landmark to the joint line of the knee, including significant differences between the sexes. Normalization of the absolute distances to femoral or tibial diameters revealed reliable spatial relationships to the joint line of the knee. The joint line was found to be equidistant from the lateral femoral epicondyle and the proximal tibio-fibular joint, representing a reproducible point of reference for joint line restoration. The authors propose a simple 3-step algorithm that can be used with magnetic resonance imaging, computed tomography, or radiography to reliably determine the anatomical location of the joint line of the knee relative to the surrounding bony anatomy. [Orthopedics. 2016; 39(6):381-386.].
authors.forename: Gavin C
authors.initials: GC
authors.lastname: Pereira
authors.forename: Ericka
authors.initials: E
authors.lastname: von Kaeppler
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Alaia
authors.forename: Kenneth
authors.initials: K
authors.lastname: Montini
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Lopez
authors.forename: Paul E
authors.initials: PE
authors.lastname: Di Cesare
authors.forename: Derek F
authors.initials: DF
authors.lastname: Amanatullah
mesh_terms: D000465:Algorithms; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D005269:Femur / Q000000981:diagnostic imaging* / Q000601:surgery; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging* / Q000601:surgery; D008279:Magnetic Resonance Imaging / Q000379:methods*; D013977:Tibia / Q000000981:diagnostic imaging* / Q000601:surgery; D014057:Tomography, X-Ray Computed