title: Vortical flow in human elbow joints: a three-dimensional computed tomography modeling study.
abstract: The human elbow joint has been regarded as a loose hinge joint, with a unique helical motion of the axis during extension-flexion. This study was designed to identify the helical axis in the ulnohumeral joint during elbow extension-flexion by tracking the midpoint between the coronoid tip and the olecranon tip of the proximal ulna in a three-dimensional (3D) computed tomography (CT) image model. The elbows of four volunteers were CT-scanned at four flexion angles (0°, 45°, 90°, and 130°) at neutral rotation with a custom-made holding device to control any motion during scanning. Three-dimensional models of each elbow were reconstructed and a 3D ulnohumeral joint at 45°, 90°, and 130° was superimposed onto a fully extended joint (0°) by rotating and translating each 3D ulnohumeral joint along the axes. The midpoints of the olecranon and coronoid tips were interpolated using cubic spline technique and the dynamic elbow motion was plotted to determine the motion of the helical axis. The means and standard deviations were subsequently calculated. The average midpoint pattern of joint motion from extension to flexion was elliptical-orbit-like when projected onto a sagittal plane and continuously translated a mean 2.14 ± 0.34 mm (range, 1.83-2.52 mm) to the lateral side during elbow extension-flexion. In 3D space, the average midpoint pattern of the ulnohumeral joint resembles a vortical flow, spinning along an imaginary axis, with an inconsistent radius from 0° to 130° flexion. The ulnohumeral joint axis both rotates and translates during elbow extension-flexion, with a vortex-flow motion occurring during flexion in 3D model analysis. This motion should be considered when performing hinged external fixation, total elbow replacement and medial collateral ligament reconstruction surgery.
authors.affiliation: Department of Orthopedic Surgery, Asan Medical Center, University of Ulsan, Seoul, Korea.
authors.forename: Arnold
authors.initials: A
authors.lastname: Adikrishna
authors.forename: Aashay L
authors.initials: AL
authors.lastname: Kekatpure
authors.forename: Jun
authors.initials: J
authors.lastname: Tan
authors.forename: Hyun-Joo
authors.initials: HJ
authors.lastname: Lee
authors.forename: Maria Florencia
authors.initials: MF
authors.lastname: Deslivia
authors.forename: In-Ho
authors.initials: IH
authors.lastname: Jeon
mesh_terms: D001696:Biomechanical Phenomena; D004551:Elbow Joint / Q000000981:diagnostic imaging* / Q000502:physiology; D006801:Humans; D006811:Humerus / Q000000981:diagnostic imaging; D021621:Imaging, Three-Dimensional; D016059:Range of Motion, Articular; D014057:Tomography, X-Ray Computed; D014457:Ulna / Q000000981:diagnostic imaging
keywords: computer-aided design; three-dimensional; ulnohumeral; vortex-flow motion
references.citation: J Orthop Res. 2000 Mar;18(2):195-202
references.pmid: 10815819
references.citation: J Bone Joint Surg Am. 1976 Jun;58(4):501-8
references.pmid: 1270470
references.citation: Comput Methods Biomech Biomed Engin. 2002 Jun;5(3):261-73
references.pmid: 12186718
references.citation: J Orthop Res. 2003 May;21(3):399-404
references.pmid: 12706011
references.citation: J Shoulder Elbow Surg. 2004 Jul-Aug;13(4):441-7
references.pmid: 15220886
references.citation: J Shoulder Elbow Surg. 2012 Aug;21(8):1006-12
references.pmid: 22036537
references.citation: J Biomech Eng. 2005 Apr;127(2):311-7
references.pmid: 15971709
references.citation: Am J Sports Med. 2013 Apr;41(4):894-902
references.pmid: 23439107
references.citation: J Orthop Trauma. 2000 Jan;14(1):41-7
references.pmid: 10630802
references.citation: Orthop Clin North Am. 2008 Apr;39(2):141-54, v
references.pmid: 18374805