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dc.contributor.advisorMaletsky, Lorin
dc.contributor.authorKomosa, Mark C.
dc.date.accessioned2012-06-03T16:36:05Z
dc.date.available2012-06-03T16:36:05Z
dc.date.issued2012-05-12
dc.date.submitted2012
dc.identifier.otherhttp://dissertations.umi.com/ku:11949
dc.identifier.urihttp://hdl.handle.net/1808/9824
dc.description.abstractPatellofemoral joint laxity is a multifactor problem that depends on the active stabilization from the quadriceps muscles, the passive stabilization from the ligaments and retinacular tissue in the PF joint, and the static stabilization from the articular geometries of the distal femur and patella. A custom patellar laxity instrument was designed and built to measure in vitro patellar laxity. The instrument measured patellar laxity envelopes through the knee flexion range for ten cadaveric knees by applying a displacement force to the patella and measuring the resultant displacement of the patella. Distinct load levels were found through the flexion range. The largest amount of patellar laxity occurred in early knee flexion (<20°) and laxity decreased with flexion after 20° knee flexion. The epicondylar width, sulcus angle, lateral trochlear slope, and medial trochlear slope were measured from MR images of the knees to correlate changes in patellar laxity variation with femoral articular geometry. Principal Component models for shift and tilt laxity were developed to assess the variation in patellar laxity. Over 78% of the variation in shift and tilt laxity was explained by the first three Principal Components. The dominant mode of variation for shift and tilt were the overall amount of laxity through the flexion range is attributed to epicondylar width and sulcus angle. Patellar shift ROM was larger through knee flexion when the subjects had smaller epicondylar width and larger sulcus angle. Another cause of variation was medial and stiffness of the PF joint which was correlated to medial trochlear slope. Subjects with more medial stiffness than the mean also had a steeper medial trochlear fact. Variation in the stiffness of the lateral retinaculum may also be contributing to the variation in medial PF joint stiffness.
dc.format.extent85 pages
dc.language.isoen
dc.publisherUniversity of Kansas
dc.rightsThis item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
dc.subjectBiomechanics
dc.subjectBiomedical engineering
dc.subjectMechanical engineering
dc.subjectKnee
dc.subjectLaxity
dc.subjectPatellar laxity
dc.subjectPatellofemoral
dc.titleAssessment of Patellar Laxity in the in vitro Native Knee
dc.typeThesis
dc.contributor.cmtememberFischer, Kenneth J.
dc.contributor.cmtememberLoudon, Janice
dc.thesis.degreeDisciplineBioengineering
dc.thesis.degreeLevelM.S.
kusw.oastatusna
kusw.oapolicyThis item does not meet KU Open Access policy criteria.
dc.rights.accessrightsopenAccess


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