Synonyms: Connexus intertendinei, Intertendinous connections
Plural: Juncturae tendinae
Location: Intermetacarpal spaces in dorsum of hand between the extensor digitorum tendons
Morphologic types:
The usual pattern is that it gets thicker from radial to ulnar side.
- Type 1: Thin filamentous (square, rhomboidal or triangular) – present only in 2nd metacarpal space
- Type 2: Thicker rhomboidal and more distally located than type I – present only in 2nd and 3rd metacarpal spaces
- Type 3: Tendon slips (longest, narrowest and thickest) – occur in 3nd and 4th intermetacarpal spaces (most common in 4th intermetacarpal space)
- 3y: splits into 2 equal halves and insert into adjacent tendons (present only in 3rd and 4th metacarpal spaces
- 3r: more oblique (present only in 3rd and 4th metacarpal spaces)
Clinical relevance
1. EIP doesn’t have junctura tendinum (identification point)
2. Lacertation of middle finger communis tendon over metacarpal just proximal to junctura may result in only partial extension loss of middle finger
Reference:
- Surgical Anatomy of the Hand and Upper Extremity edited by James R. Doyle
- Campbell’s Operative Orthopedics – 13th Edition
