title: Structure modeling of the glenoid: Relevance to shoulder arthroplasty.
abstract: We applied shape modeling and principal component analysis (PCA) to discover glenoid bone structural relationships relevant to improving glenoid prosthesis features, fixation, and instrumentation. Knowledge of external bone morphology guides prosthesis shape and positioning, while internal bone morphology and bone density influence fixation. CT-based modeling defined nonarthritic glenoid subchondral bone surface and internal structure. First and second principal shape components were related to size and density. Reproducible structural parameters and glenoid feature relationships were discovered. Subchondral bone surface was approximated by a circle inferiorly and a triangle superiorly with the circle's center at a reproducible point along a superior-inferior line. Glenoid vault's maximum depth was at the circle's center, and the highest bone density was in posterior glenoid. Glenoid subchondral bone surface version varied from superior to inferior, but not by sex or side. Male subchondral bone surfaces were larger and more retroverted. Even if subchondral bone surfaces are deformed by arthritis, glenoid morphology can be identified by extra-articular landmarks, permitting location of the glenoid center and scapular orientation (glenoid version). Knowledge obtained from this study directs design of novel prosthesis features and instrumentation for use without pre-op CT or computer aided surgery.
authors.affiliation: Emory Spine and Orthopaedic Center, Atlanta, Georgia, 30329; Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, 30030; Schulich School of Engineering, Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, AB, T2N 1N4, Canada.
authors.forename: Gulshan B
authors.initials: GB
authors.lastname: Sharma
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: McMahon
authors.forename: Douglas D
authors.initials: DD
authors.lastname: Robertson
mesh_terms: D000328:Adult; D000368:Aged; D019643:Arthroplasty, Replacement; D003198:Computer Simulation; D005260:Female; D061165:Glenoid Cavity / Q000033:anatomy & histology / Q000503:physiopathology*; D006801:Humans; D021621:Imaging, Three-Dimensional; D007595:Joint Prosthesis; D008297:Male; D008875:Middle Aged; D025341:Principal Component Analysis; D011474:Prosthesis Design; D015203:Reproducibility of Results; D012782:Shoulder / Q000601:surgery*; D012785:Shoulder Joint / Q000601:surgery; D014057:Tomography, X-Ray Computed
keywords: glenoid; glenoid prosthesis; shape modeling; surgical instrumentation; total shoulder arthroplasty