The Distal Interosseous Membrane: Current Concepts in Wrist Anatomy and Biomechanics
ABSTRACT The distal interosseous membrane (DIOM) of the forearm acts as a secondary stabilizer of the distal radioulnar joint (DRUJ) when the dorsal and palmar radioulnar ligaments of the triangular fibrocartilage complex are cut. Recent anatomical studies revealed that thickness of the DIOM varies widely among specimens and the distal oblique bundle (DOB) exists within the DIOM in 40% of specimens. The DOB originates from the distal one-sixth of the ulnar shaft and runs distally to insert on the inferior rim of the sigmoid notch of the radius. The mean thickness of the DIOM without a DOB was 0.4 mm, which was significantly thinner than 1.2 mm with a DOB. Biomechanical studies have shown that the DOB is an isometric stabilizer of the forearm during pronosupination. The presence of a DOB was shown to have a significant impact on DRUJ stability. Innate DRUJ laxity in the neutral forearm position was greater in the group without a DOB than in the group with a DOB. Ulnar shortening with the osteotomy performed proximal to the attachment of the DIOM had a more favorable effect on stability of the DRUJ compared with the effect of distal osteotomy, especially in the presence of a DOB. The longitudinal resistance to ulnar shortening was significantly greater in proximal shortening than in distal shortening. It also suggested that the DIOM is of great importance in the management of concomitant ulnar-side injuries in distal radius fracture.
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ABSTRACT: Introduction The dorsal capsular imbrication of the distal radioulnar joint (DRUJ) which was performed because of posttraumatic dorsal instability showed promising functional results after the first postoperative years. Therefore, we hypothesized that patients after capsular imbrication are characterized by good subjective and functional outcome measurements after a midterm period. Materials and methods Eleven patients (range 21-50 years of age; median 35 years of age) were examined after capsular imbrication of the DRUJ because of posttraumatic instability with a mean follow-up time of 72 months (range 46-114 months; median 66 months). Examination parameters included the determination of range of motion (ROM), grip strength, pain and functional outcome scores (modified Mayo wrist score (MMWS); Disabilities of the Arm, Shoulder and Hand questionnaire (DASH score)). Results A mean DASH score of 6.7 (range 0-22.5) and mean MMWS of 91.8 (range 75-100) were measured. Grip strength reached 96.7 % of the contralateral hand. Range of motion reached at least 93.1 % of the contralateral hand. Eight of 11 patients regarded functional outcome and pain reduction as excellent. Six of 11 patients did not recognize a diagnosed instability of DRUJ as such. Ulnar-sided wrist pain was the apparent symptom in these cases. Conclusions Capsular imbrication of the DRUJ is a reliable and sufficient treatment option in case of posttraumatic dorsal instability. Since DRUJ instability is seldom recognized by the patients as such, a standardised diagnostic algorithm is mandatory to guarantee reliability and efficacy for identifying DRUJ instability.Archives of Orthopaedic and Trauma Surgery 10/2014; 134(11). DOI:10.1007/s00402-014-2092-7 · 1.31 Impact Factor
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ABSTRACT: Background Loss of forearm rotation is frequently seen after healing of distal radius fractures. Questions/Purposes Our purpose was to determine whether restricted excursion of the pronator quadratus muscle can affect forearm rotation. Methods We evaluated the relationship between pronator quadratus excursion and forearm rotation in a cadaveric model. Eight adult fresh-frozen above-elbow specimens were attached to a mounting device that permitted free rotation of the forearm around its ulnar axis. Forearm rotation was measured with a protractor while alternating pronation and supination loads were applied. Measurements were repeated after restricting the excursion of pronator quadratus by 10, 20, and 30% of its initial length. Results There was a mean 15° loss of supination for each 10% reduction in pronator excursion. There was no significant effect on pronation. Conclusions We conclude that, independent of any bone deformity or nearby joint stiffness, posttraumatic scarring of this muscle may result in a loss of supination.08/2014; 3(3):198-202. DOI:10.1055/s-0034-1384744
The Journal Of Hand Surgery 10/2014; DOI:10.1016/j.jhsa.2014.08.022 · 1.66 Impact Factor