1. extensor
   1. Subtopic 1
      1. extensor expansion (dorsal expansion, dorsal hood): extensor tendon will expand to form a hood, which covers the back and sides of the head of the metacarpal and the proximal phalanx then devides to 3 bands
         1. I. lateral bands pass on either side of the proximal phalanx and stretch all the way to the distal phalanx
            1. Attach to the 1.lumbricals 2.extensor indicis muscle,3. dorsal & palmar interossei
            2. Subtopic 1
            3. Subtopic 2
         2. II. central slip attach to the dorsal of the middle phalanx
         3. III. retinacular ligament runs obliquely along the middle phalanx, and connects the fibrous digital sheath on the anterior side of the phalanges to the extensor expansion.
   2. Subtopic 2
   3. extebsir zibes: Zone 1 (distal interphalangeal [DIP] joint) Zone 2 (middle phalanx) Zone 3 (proximal interphalangeal [PIP] joint) Zone 4 (proximal phalanx) Zone 5 (metacarpophalangeal [MCP] joint) Zone 6 (dorsum of hand) Zone 7 (wrist) Zone 8 (dorsal forearm)
2. Kirchmayr tendon laceration repair suture
   1. Kirchmayr tendon laceration repair suture technique.
   2. Subtopic 2
   3. Subtopic 3
3. Main Topic 3