- See:
- Zone I injuries
- Zone II injuries
- Zone III injuries
- Zone IV and Zone V:
- Discussion:
- FDS serves as an isolated activator of middle phalanx;
- function is determined by holding adjacent phalanges in extension so that flexor profundi cannot move;
- this is works for index & long fingers & usually ring finger;
- little finger should be tested by simultaneously flexing ring finger, since little finger may have a single muscle belly w/ tendons
to each of digits;
- Advantages of Superficialis Repair:
- repaired FDS increases digit strength;
- improved flexion at PIP joints
- preserves short vincula which provides blood supply to FDP and improves healing potential;
- acts as pulley for repaired profunda that provides improved excursion and strength;
- intact FDS prevents PIP hyperextension and DIP hyperflexion;
- Indications for FDS Sacrifice:
- when tendon repair requires sacrifice of pulleys
- when both tendons are lacerated & need to be immobilized at same level;