title: How does wrist position affect the length of the distal radioulnar ligament: a three-dimensional image study in vivo?
abstract: OBJECTIVE
  This study was designed to investigate the length changes of the distal radioulnar ligament at different wrist positions and to determine the effect of hyperextension on the distal radioulnar ligament and to find out the most vulnerable position where the distal radioulnar ligament rupture and foveal avulsion.
  
  
  METHODS
  We obtained computed tomography scans of the wrists for 12 volunteers including two groups: hyperextension group and hyperextension with maximal rotation group. The images were reconstructed to the three-dimensional bone structures with customized software. The four portions of the distal radioulnar ligament were measured and analyzed statistically.
  
  
  RESULTS
  No significant differences were noted in the lengths of the each portion of the distal radioulnar ligament among neutral position, wrist hyperextension, and hyper-radial extension. From neutral position to hyperextension with maximal pronation, the lengths of the palmar superficial radioulnar ligament (psRU) and dorsal deep radioulnar ligament (ddRU) decreased significantly, whereas the dorsal superficial radioulnar ligaments (dsRU) and palmar deep radioulnar ligament (pdRU) increased significantly. From neutral position to hyperextension with maximal supination, the lengths of the pdRU and dsRU ligaments decreased significantly, and the lengths of psRU and ddRU ligaments changed little.
  
  
  CONCLUSIONS
  The factor of hyperextension has little effect on the length of the distal radioulnar ligament and the distal radioulnar ligament may be under great tension at the position of hyperextension with maximal pronation. These findings can provide more information to understand the pathomechanics of the triangular fibrocartilage complex injury caused by a fall on the outstretched hand and can provide information relevant to the distal radioulnar ligament restoration.
authors.affiliation: Department of Medical Research Center of Jiangsu Province, Affiliated Hospital of Nantong University Nantong, Nantong, Jiangsu, China.|Department of Hand Surgery, Hand Surgery Research Center, Affiliated Hospital of Nantong University, 20 West Temple Road, Nantong, 226001, Jiangsu, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Medical Research Center of Jiangsu Province, Affiliated Hospital of Nantong University Nantong, Nantong, Jiangsu, China.|Department of Hand Surgery, Hand Surgery Research Center, Affiliated Hospital of Nantong University, 20 West Temple Road, Nantong, 226001, Jiangsu, China.
authors.forename: Yu Cheng
authors.initials: YC
authors.lastname: Sun
authors.affiliation: Department of Medical Research Center of Jiangsu Province, Affiliated Hospital of Nantong University Nantong, Nantong, Jiangsu, China.|Department of Hand Surgery, Hand Surgery Research Center, Affiliated Hospital of Nantong University, 20 West Temple Road, Nantong, 226001, Jiangsu, China.
authors.forename: Qing Zhong
authors.initials: QZ
authors.lastname: Chen
authors.affiliation: Department of Internal Medicine, Affiliated Hospital of Nantong University, Nantong, Jiangsu, China.
authors.forename: Ai Xian
authors.initials: AX
authors.lastname: Zhang
authors.affiliation: Department of Medical Research Center of Jiangsu Province, Affiliated Hospital of Nantong University Nantong, Nantong, Jiangsu, China. 33240338@qq.com.|Department of Hand Surgery, Hand Surgery Research Center, Affiliated Hospital of Nantong University, 20 West Temple Road, Nantong, 226001, Jiangsu, China. 33240338@qq.com.
authors.forename: Jun
authors.initials: J
authors.lastname: Tan
mesh_terms: D000328:Adult; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D021621:Imaging, Three-Dimensional; D008023:Ligaments, Articular / Q000000981:diagnostic imaging / Q000502:physiology*; D008297:Male; D014057:Tomography, X-Ray Computed; D014955:Wrist Joint / Q000000981:diagnostic imaging / Q000502:physiology*; D055815:Young Adult
keywords: Biomechanics; Distal radioulnar ligament; Forearm rotation; Wrist