Gray Anatomy pics with motor testing and nerve innervation for both volar/dorsal surfaces of hand and forearm
DIP Dislocation: rare, usually dorsal if it does occur. Longitudinal pull, hyperextension with dorsal pressure to base.
PIP Dislocation: much more common. Usually dorsal with volar plate disruption. Usually ulnar deviated. Longitudinal pull. hypertension and dorsal pressure to base after digital block.Splint in 30 degrees flexion. May require surgery later.
MCP Dislocation: Usually dorsal, more subluxation than true dislocation. Reduce by flex the wrist to relax flexor tendons, apply pressure to dorsum of proximal phalanx in distal/volar direction.
Thumb MCP Dislocation: Dorsal from hyperextension with volar plate rupture. Reduce with pressure distal to base of proximal phalanx with metacarpal flexed and abducted.
Gamekeeper’s Thumb / Skier’s Thumb: Gamekeeper from twisting the heads off rabbits. Ulnar collateral ligament rupture from radial deviation of MCP. Pain to ulnar aspect of thumb, weakness of pincer function. Hand surgery referral. Thumb spica splint.
Distal Phalanx Fracture: Protective splinting.
Proximal/Middle Phalanx Fracture: Early protected ROM by buddy taping for nondisplaced/stable fx. Midshaft transverse, spiral, and intra-articular fractures often require internal fixation.
Metacarpal Fractures: Neck fractures due to direct impaction. Little finger (V) referred to as boxer’s fracture. Angulation laxity: II-III: < 15 degrees, IV: < 20 degrees, V: < 40 degrees. Splint in 20 degree extension and MCP flexed at 90 degrees. Metacarpal base fractures usually involve carpal bone fractures.
Bennett Fracture: intra-articular fx by impaction with subluxation/dislocation at CMC. Thumb spica splint.
Rolando Fracture: intra-articular communiated fracture at metacarpal base. Thumb spica splint.
Compartment syndrome: Think about with IV extravasation, arterial punctures.
High-Pressure Injection Injury: Looks benign on the outside, but has extreme high risk of internal damage and morbidity. Treatment early surgical debridement and decompression. Immobilize, elevate, tetanus, and abx. Amputation rate can be 30%.
Q1. What type of thumb fracture has intra-articular involvement with dislocation or subluxation?
A. Bennett Fracture. Wrong answers: Rolando, Skier’s Thumb, Boutonniere, Mallett.
Q2. What is injured in a Gamekeeper/Skier’s Thumb?
A2. Ulnar Collateral liagament. Wrong answers: intraarticular MCP fracture of thumb (Rolando), FDP of second finger (jersey finger), Distal dorsal tendon injury to DIP (mallet finger).
Q3. Show picture of initial injection from high pressure injection injury. Ask for treatment.
A3. Emergent surgical consult, emergent debridement/decompression. Wrong answers, IV antibiotics, admission (Human bite), Splint with close followup (simple tendon/wound laceration), leave open with dressing and close followup (dirty wound, delayed closure).
Tintinalli, Seventh Edition, Chapter 265: Injuries to the Hand and Digits