Dorsal view left hand
Dorsal view left hand
Volar view left hand
Thumb Metacarpal-phalangeal joint injury usually result from thumb hyperextended with a forced abduction force, commonly during a skiing injury. Chronic over distension may also occur as with an occupational hazard, as classically described as Gamekeepers thumb injury.
Thumb MCP joint extended with hyperabduction
Stress testing MC-P1 joint:
> 15° compared to the contralateral uninjured side indicates instability
Grade I | No laxity |
Grade II | Mild laxity with end point |
Grade III | Laxity with no end point |
Hinterman Classification | |
Type I | Non-displaced, stable in flexion (< 35o stress test) |
Type II | Displaced fracture |
Type III | No fracture, stable in flexion (< 35o stress test) |
Type IV | No fracture, , unstable in flexion (< 35o stress test) |
Type V | Avulsion fracture of Volar plate, stable in flexion |
Type VI | Fragmentation of volar ulnar portion of P1 with associated injury of the UCL |
Thumb spica POP
Dorsoulnar approach:
Incision: 1cm proximal to MCP joint extended in a palmar direction around the ulnar aspect of the joint.
Overlying the ulnar collateral ligament include adductor pollicis aponeurosis & dorsal sensory branch of Radial nerve. Retract nerve & divide adductor pollicis aponeurosis overlying the UCL.
Repair UCL with anchor. Alternatively pass suture fixation to ligament through drill holes of P1 and tie on opposite bone end.
Active wrist ROM after 2 weeks
Finger adduction strengthening
Finger abduction strengthening
Hand grip strengthening