title: A new device to measure knee laxity during weightbearing and non-weightbearing conditions.
abstract: The Vermont knee laxity device (VKLD) was developed to evaluate anterior-posterior (A-P) displacement of the tibia relative to the femur (A-P laxity) during weightbearing and non-weightbearing conditions. The purposes of this study were to determine the repeatability and reliability of the VKLD measurements of A-P laxity and to compare them with two devices currently in clinical use: the KT-1000 knee arthrometer and planar stress radiography. Two independent examiners tested six subjects with no history of knee injury. A-P laxity was measured on three separate days with the KT-1000 and the VKLD. With the VKLD, A-P laxity was measured in the weightbearing and non-weightbearing conditions. In addition, one examiner measured A P laxity in each subject on each day using a planar stress radiography technique. Similar A-P laxity values were obtained with the KT-1000 and the VKLD; however, the planar stress radiography technique measured less A-P laxity compared to the VKLD (9.2+/-2.2 mm versus 13.3+/-2.9 mm, P = 0.0004). None of the three devices showed significant differences in measuring A-P laxity between days. During weightbearing, A-P laxity was reduced by 65-70% compared to the non-weightbearing condition (P = 0.0001). Future investigations will use the VKLD to study subjects that have suffered injury to the anterior and posterior cruciate ligaments.
authors.affiliation: Department of Orthopaedics and Rehabilitation, McClure Musculoskeletal Research Center, University of Vermont, Burlington 05405-0084, USA.
authors.forename: B S
authors.initials: BS
authors.lastname: Uh
authors.forename: B D
authors.initials: BD
authors.lastname: Beynnon
authors.forename: D L
authors.initials: DL
authors.lastname: Churchill
authors.forename: L D
authors.initials: LD
authors.lastname: Haugh
authors.forename: M A
authors.initials: MA
authors.lastname: Risberg
authors.forename: B C
authors.initials: BC
authors.lastname: Fleming
authors.forename: B S
authors.initials: BS
authors.lastname: Un
mesh_terms: D000293:Adolescent; D000328:Adult; D004864:Equipment and Supplies; D005260:Female; D005269:Femur / Q000502:physiology*; D006801:Humans; D007717:Knee / Q000502:physiology*; D008297:Male; D013977:Tibia / Q000502:physiology*; D016474:Weight-Bearing