- Central slip that extends the PIP (attaches to dorsal middle phalanx)
- 2 lateral bands that extend the DIp (attaches to dorsal distal phalanx)
- Flexor digitalis superficialis flexes the PIP (attaches to base of middle phalanx)
- Flexor digitalis profundus flexes the DIP (attaches to base of distal phalanx)
There are also collateral ligaments (at the side) and volar plate (at base) providing support for the fingers.
Common finger injuries involving tendons & ligaments
Evaluating FDP injury: profundus & superficialis test
Evaluating collateral ligament injury: valgus & varus test
Types of splint used:
Extension splint for extensor tendon injuries
Note that patient should keep finger in extension for 6 weeks.
- Splinting has to be restarted if patient flexes the finger.
- Hyperextension can cause circulatory impairment. A blanched finger = too much extension. Allowing the skin to “breathe” for 10 to 20 minutes between splint changes minimizes the risk of maceration.
Buddy splint for collateral ligament injury
Progressive extension splint for volar plate injury (using dorsal aluminium splint)
JEFFREY C. LEGGIT, CHRISTIAN J. MEKO. Acute Finger Injuries: Part I. Tendons and Ligaments. Am Fam Physician