Juncturae Tendinum Exam

  • Juncturae tendinum's fascial edge can be seen and palpated between the metacarpal heads when the patient makes a tight fist. 
  • Juncturae tendinum occur in the intermetacarpal spaces two, three, and four. They are not seen between thumb and index extensors.

  • Juncturae tendinum can mask a laceration of an extensor digitorum communis tendon by providing active extension of the metacarpophalangeal joint when the extensor digitorum communis is actually cut completely.

     

Diagrams & Photos
  • The junctura tendinum move distally as the patient makes a fist. In this position the junctura can be seen as a visible palpable fascial ridge between the metacarpal heads. See the 4-5 junctura at the tip of the pen.
    The junctura tendinum move distally as the patient makes a fist. In this position the junctura can be seen as a visible palpable fascial ridge between the metacarpal heads. See the 4-5 junctura at the tip of the pen.
  • With extension the junctura move proximally and are more difficult to see and palpate. Note the 4-5 junctura and the tip of the pen.
    With extension the junctura move proximally and are more difficult to see and palpate. Note the 4-5 junctura and the tip of the pen.
  • Juncturae Tendinum (Juncturae Tendinae)
    (Juncturae Tendinae)
  • A laceration of the EDM can be masked on active range of motion testing by an intact juncturae tendon (yellow arrow).
    A laceration of the EDM can be masked on active range of motion testing by an intact juncturae tendon (yellow arrow).
Key Points
  • Juncturae tendinum distribute extensor forces, coordinate, and stabilize the extensor digitorum communis slips.
Grading of Muscle Strength
Exam References
Anatomic Abbreviations
Hand Surgery Resource Exams & Signs Library