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Basal fractures of the thumb
base
Sudhir Warrier
Mumbai
Thumb CMC joint
• Biconcave – convex saddle joint
• Range of motion :
55° flexion – extension
40° abduction – adduction
• Minimal bony constraints
• Large Cantilever forces
The cantilever forces
The lack of bony constraints
How many ligaments are required to stabilize
one such joint????
16 !
The important ligaments of the thumb
basal joint
The dAOL (beak ligament) DRL and the POL are the main stabilisers
The beak ligament
deep Anterior Oblique Ligament-dAOL
• Restrains the joint and prevents dorsal
translation of the metacarpal
The Dorsal radial Ligament (DRL)
• Covers most of the dorsal aspect
• Is one of the main stabilisers
• Is taut in all positions except extension
These ligaments come into play in
intra-articular fractures
Types
Highly unstable fractures
Antegrade
entry will
jeopardise the
CMC joint
Bennett Fracture
Forces destabilising the metacarpal
As the fracture renders the
ligamentous moorings useless!
There are 25 techniques of treatment
listed in David Greens Book!!!
From 1908 – (Cast and skin traction)
To Tiny Herbert screws!
Closed reduction
• Is used for minimally displaced fractures that
can be reduced
• Unstable fractures are difficult to control in
plaster
• Pinning is more reliable
Function at the time of wire removal
Comminuted unstable basal fractures
Comminuted unstable basal fractures
need multiple wires
Congruity and relocation
Reducing the fragments and achieving
congruity is the key
How to image this area?
AP view
Lateral view
Roberts Pronated True AP view
The supinated AP view –STT joint
Stage V
Stage IV
Pronated and Supinated AP
All of them work so long as
the congruity is maintained.
A UMEX frame
Anatomic reduction
Complex injury!
A CT scan resolves the dilemma
Approach
Trapezium restored
Congruity ensures stability
Non-reconstructable
Sudhir Warrier
Sudhir Warrier
Turn on computer
s
Open a blank “Word” file
Hold the x ray against it
a
Click pic without flash
Whatsapp it NOW !
Sudhir Warrier
Iatrogenic Loss!
Sudhir Warrier
Sudhir Warrier
Sudhir Warrier
Sudhir Warrier
opponensplasty
Sudhir Warrier
Sudhir Warrier
Sudhir Warrier
It functions
But only like a post!
The power of remodeling
What happens if it malunites?
Dome osteotomy and correction
Boxer – chronic injury
The left hook is lethal!
Summary
• Image correctly to identify the severity
• Use the appropriate method to stabilise the
fracture
• Malunion can be symptomatic, requiring
corrective surgery