title: Effect of arthroscopic procedures on the acromioclavicular joint.
abstract: The objective of the current study was to determine the effect of arthroscopic acromioplasty, and combined acromioplasty and distal clavicle resection on joint kinematics and in situ forces in response to an anterior, posterior, and superior load of 70 N. The loading conditions were applied to 10 fresh-frozen cadaveric shoulders using a robotic and universal force and moment sensor testing system. Translations in response to a posterior load increased by approximately 30% after combined acromioplasty and distal clavicle resection when compared with the intact and acromioplasty conditions. The in situ force in the trapezoid and conoid ligaments increased significantly from 13 +/- 15 N to 40 +/- 25 N and 13 +/- 13 N to 38 +/- 28 N, respectively, between the intact and combined acromioplasty and distal clavicle resection conditions during anterior loading. The results suggest that an arthroscopic acromioplasty alone does not significantly affect the mechanics of the acromioclavicular joint with these loading conditions. However, an acromioplasty combined with a distal clavicular resection does result in significant increases in joint motion and ligament forces. In some circumstances, such as after a previous joint separation, the increased forces in the coracoclavicular ligaments could result in additional damage to weak ligaments.
authors.affiliation: Musculoskeletal Research Center, Department of Orthopaedic Surgery, University of Pittsburgh, 210 Lothrop Street, E1641 BST, PO Box 71199, Pittsburgh, PA 15213, USA. genesis1@pitt.edu
authors.forename: Richard E
authors.initials: RE
authors.lastname: Debski
authors.forename: James A
authors.initials: JA
authors.lastname: Fenwick
authors.forename: Albert
authors.initials: A
authors.lastname: Vangura
authors.forename: Freddie H
authors.initials: FH
authors.lastname: Fu
authors.forename: Savio L-Y
authors.initials: SL
authors.lastname: Woo
authors.forename: Mark W
authors.initials: MW
authors.lastname: Rodosky
mesh_terms: D000173:Acromioclavicular Joint / Q000502:physiology / Q000601:surgery*; D000368:Aged; D000704:Analysis of Variance; D001182:Arthroscopy / Q000379:methods*; D001696:Biomechanical Phenomena; D002102:Cadaver; D004867:Equipment Design; D005260:Female; D006801:Humans; D016018:Least-Squares Analysis; D008023:Ligaments, Articular / Q000502:physiology; D008297:Male; D008875:Middle Aged; D012371:Robotics; D013314:Stress, Mechanical