Hiroshi Watanabe

Publications (2)2.71 Total impact

• Article: Contribution of the interosseous membrane to distal radioulnar joint constraint.

  Hiroshi Watanabe, Richard A Berger, Lawrence J Berglund, Mark E Zobitz, Kai-Nan An
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  ABSTRACT: Although forearm injuries are accompanied frequently by rupture to the interosseous membrane (IOM) diagnosis of the extent of IOM injury is difficult. In this study we evaluated distal radioulnar joint (DRUJ) laxity caused by both partial and complete IOM disruption and compared these quantitative measurements with the common clinical manual evaluation of DRUJ laxity and dislocatability. Human cadaveric forearms (n = 8) were used in this study. Skin, muscles, and tendons were removed. The specimens were mounted on an experimental apparatus that allowed the radius to move freely about the fixed ulna. Tests were performed in neutral rotation, 60 degrees pronation, and 60 degrees supination. Under various conditions of IOM sectioning testing was performed by volary and dorsally translating the radius relative to the ulna in the coronal plane of the radius. Testing was performed both qualitatively as would be performed in the clinic and quantitatively with an instrumented probe. Our results show that dorsal dislocation of the radius relative to the ulna strongly suggests distal IOM rupture. Disengagement of the radius from the DRUJ indicated injury to the distal and middle IOM. The distal IOM constrained volar and dorsal laxity of the radius at the DRUJ in all forearm rotation positions. The midportion of the IOM constrained laxity except in the volar direction of the pronated forearm. The proximal IOM did not constrain the proximal radius except dorsally for the pronated forearm position. The IOM, in particular the distal IOM, plays an important role in constraining dorsal dislocation of the radius at the DRUJ.
  The Journal Of Hand Surgery 12/2005; 30(6):1164-71. · 1.35 Impact Factor
• Article: Stability of the distal radioulnar joint contributed by the joint capsule.

  Hiroshi Watanabe, Richard A Berger, Kai-Nan An, Lawrence J Berglund, Mark E Zobitz
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  ABSTRACT: The distal radioulnar joint (DRUJ) capsule is assumed to be an important stabilizer of the DRUJ. There are few published data regarding the capsule and its specific contribution to stability of the DRUJ. We analyzed the contribution of the joint capsule to DRUJ stability in a biomechanical study consisting of collection of force/displacement data from 16 adult human cadaveric upper extremities. Each specimen was subjected to anteroposterior translation testing of the radius relative to the ulna in 3 positions of forearm rotation (neutral, 60 degrees pronation, 60 degrees supination) by serial sectioning of the DRUJ capsule. The experimental conditions tested included intact capsule, sectioned dorsal capsule, sectioned volar capsule, and repaired capsule. Isolated dorsal capsule sectioning resulted in volar instability of the radius to the ulna primarily in the maximum pronated position. Significant dorsal instability of the radius was observed after isolated volar capsule sectioning in the maximum supinated position. The restabilizing effect of capsule shortening was observed near the maximums of forearm rotation. The additional stability owing to capsule shortening surpassed that of the distal radioulnar ligament at these positions. We showed the effect of capsular injury on DRUJ joint stability and the restabilizing effect of capsule shortening. The importance of the capsule to DRUJ stability should be considered when planning surgical procedures to restore the unstable DRUJ.
  The Journal Of Hand Surgery 12/2004; 29(6):1114-20. · 1.35 Impact Factor