This document provides an overview of distal radius fractures, including: - The history and key descriptions of these fractures dating back to the 18th century. - Distal radius fracture demographics, including higher rates in certain age groups and genders. - Surgical anatomy of the distal radius and surrounding ligaments. - Biomechanics of the distal radius including measurements like radial inclination and ulnar variance. - Pathomechanisms of posteriorly and anteriorly displaced distal radius fractures. - Principles and techniques for implants used in distal radius fracture treatment, including ligamentotaxis, plating approaches, and K-wire fixation.

1. INTRODUCTION, SURGICALANATOMY/APPLIED
ANATOMY, DEMOGRAPHICS OF DISTAL RADIUS
FRACTURES, BIOMECHANICS OF FRACTURES AND
IMPLANTS
DR.AKHILESWARI
I I YR PG

2. HISTORY
• First surgeon to recognize these injuries was Pouteau in
1783.
• Later Abraham Colles in 1814 gave the classic
description of fracture
• Dupuytren brought to the world attention that it is a
fracture rather than a dislocation as it was previously
assumed.
• Barton in1838 described wrist subluxation consequent to
intraarticular fracture of radius which could be dorsal or
volar.
• Smith described fracture of distal radius with ‘forward’
displacement.

3. INTRODUCTION:
• Distal radius fractures represent approximately one
sixth(20%) of all fractures
• Distal radius fractures occur through the distal metaphysis of
the radius
• May involve articular surface
• frequently involves the ulnar styloid

4. SURGICAL ANATOMY:
ARTICULAR SURFACE OF DISTAL RADIUS :
• Triangular in shape . The base of the triangle is formed by
the sigmoid notch and apex by the radial styloid
• Has scaphoid and lunate fossae which articulate with the
scaphoid and lunate bones respectively.
• The articular surface is inclined both in a volar and ulnar
direction
• The sigmoid notch is semi cylindrical in shape allowing
rotation of the radius around the ulnar head

6. PALMAR SURFACE OF RADIUS:
• Concave from proximal to distal
• Smooth-easy contouring of plates
• Provides attachment to radiocarpal ligaments-acts as
restraints to the normal tendency of carpus to slide in a
volar and an ulnar direction
DORSAL SURFACE:
• Convex and irregular
• Most prominent area- LISTER’S tubercle
• Grooves – form the floors of extensor compartments

7. Cross-sectional anatomy of the radial metaphysis. Note that the
dorsal surface is much more irregular than the palmar surface. The
V-shape dorsally caused by Lister's tubercle (arrow) makes it
difficult to contour a plate to fit the dorsum of the radius

9. • Metaphysis has thinner cortical bone dorsoradially
Fracture typically collapses dorsoradially
• Greatest trabecular density lies in the palmar ulnar cortex
• Radial styloid rotates palmarly 150 off the axis of the
radius(makes capture difficult from a dorsal approach)

10. The cross sectional anatomy of radius with comminution dorsally and
radially. The tendency to dorsal collapse is the result of dorsal
comminution and the collapse at the midcarpal joint

11. LIGAMENTOUS ANATOMY:
• The extrinsic ligaments of the wrist play a major role in the
use of indirect reduction techniques
• The palmar extrinsic ligaments are attached to the distal
radius, and it is these ligaments that are relied on to reduce
the components of a fracture using closed methods.

12. • There are two factors about these ligaments that make
them significant for reduction
1. orientation of the extrinsic ligaments from the
radial styloid is oblique relative to the more
vertical orientation of the ligaments attached to
the lunate facet.
2. thicker palmar ligaments when compared to
the thinner dorsal ligaments

13. Dorsal ligaments are oriented in a relative “z” orientation,
which allows them to lengthen with less force than the more
vertically oriented palmar ligaments
Distraction will result in the palmar ligaments becoming taut
before the dorsal ligaments.
Palmar cortex is brought out to length before the dorsal
cortex
Difficult to achieve reduction of the normal 12 degrees of
palmar tilt using distraction alone

14. Z shaped orientation of the palmar ligaments. Compared to the
palmar ligaments the dorsal ligaments must stretch further to
achieve reduction of the palmar tilt.

15. ROLE OF TFCC
• Also known as as ulnoligamentous complex
• It consists of
 The triangular fibrocartilage (TFC or articular disk),
 Meniscal homologue,
 Ulnocarpal [ulnolunate (UL) and lunotriquetral]
ligaments,
 The dorsal and volar radioulnar ligaments,
 Ulnar collateral ligament, and
 The extensor carpi ulnaris (ECU) subsheath
• TFCC is the main stabiliser of distal radioulnar joint in
addition to contributing to ulnocarpal stability

16. • TFCC normally not only stabilises the ulnar head in
sigmoid notch of radius but also acts as a buttress to
support proximal carpal row
• During axial loading the radius carries the majority of
load(82%),and the ulna a smaller load(18%)
• Increasing the ulnar variance to a positive 2.5mm
increases the load transmission across the TFCC to 42%
• The TFCC excised the radial load increases to 94%

17. UL- ulno lunate
ligament
UT- ulno triquetral
ligament
TFC- triangular
fibrocartilage or articular
disc
ECU- extensor carpi
ulnaris sheath

19. APPLIED ANATOMY:
• Jakob and his co-
authors interpreted the
wrist as consisting of
three distinct columns,
each of which is
subjected to different
forces and thus must
be addressed as
discrete elements

20. • The radial column consists of
the scaphoid fossa and the radial
styloid.
• Because of the radial inclination
of 22 degreees, impaction of the
scaphoid on the articular surface
results in a shear moment on the
radial styloid causing failure
laterally at the radial cortex.
• The radial column, therefore, is
best stabilized by buttressing the
lateral cortex
RADIAL/LATERAL COLUMN:

21. • Consists of the lunate fossa and the sigmoid notch(DRUJ)
• Cornerstone of the radius because it is critical for both
articular congruity and distal radioulnar function.
• Failure - occurs as a result of impaction of the lunate on
the articular surface with dorsal comminution.
• The column is stabilized by a direct buttress of the dorsal
ulnar aspect of the radius
INTERMEDIATE COLUMN:

22. MEDIAL COLUMN:
The ulnar column consists of the distal ulna
with the triangular fibrocartilage complex

23. DEMOGRAPHICS
• Incidence is both age and gender dependent
• There are three main peaks of fracture distribution
 children aged 5-14 years,
 male aged under 50 years and (athletic and high
energy injuries)
 females over the age of 40 years (fragility
fractures)
• Majority of fractures in the elderly are extraarticular and
there is higher incidence of intra articular fractures in the
younger patients

24. BIOMECHANICS
RADIAL INCLINATION:
• Inclination of radius towards the ulna
• measured by the angle between a line drawn from the
tip of the radial styloid to the medial corner of the
articular surface of the radius and a line drawn
perpendicular to the long axis of the radius
Normal 220
Acceptable range - <50 loss

25. • Measured by a line drawn perpendicular to the long axis
of the radius and tangential to the most distal point of the
ulnar head and a line drawn perpendicular to the long axis
of the radius and at the level of the tip of the radial styloid
• Average : 11 mm (8-18)
Acceptable <4mm loss compared to
opp wrist
>4mm increased load on lunate facet
RADIAL LENGTH:

26. DORSAL/PALMAR TILT:
 A line is drawn
connecting the most
distal points of the volar
and dorsal lips of the
radius. The dorsal or
palmar tilt is the angle
created with a line
drawn perpendicular
along the longitudinal
axis of the radius

27. • A line parallel to the medial corner of the articular surface
of the radius and a line parallel to the most distal point of
the articular surface of the ulnar head, both of which are
perpendicular to the long axis of the radius
• Measure of radial shortening
• Normal : -2 to +2 mm
ULNAR VARIANCE:

28. • In lateral view, one line is drawn along the long axis of
the capitate and one down the long axis of the radius. If
the carpus is aligned, the lines will intersect within the
carpus. If not, they will intersect outside the carpus.
CARPAL MALALLIGNMENT:

29. PATHOMECHANISM OF POSTERIORLY
DISPLACED FRACTURE
• The usual cause is fall on the hyperextended wrist
• A)THE THEORY OF COMPRESSION
IMPACTION
In hyperextension proximal carpal bones come and
impact dorsal aspect of radius and body weight is
transmitted through long axis of radius to distal end and
compression occur at dorsal aspect of distal radius leading
to fracture

30. B)THE AVULSION THEORY-
The indirect force presented by the
body weight is transmitted through humerus, ulna, radius and
then to volar wrist ligaments. Fracture occurs by avulsion
mechanism applied by the tensile forces transmitted by the
volar wrist ligaments

31. THE INCURVATION THEORY-
Depends on position of
the hand, the extent of the area of impact, the magnitude of
the applied force

32. PATHOMECHANISM OF ANTERIORLY
DISPLACED FRACTURE
1. Axial stress on the radius with a backward fall on the
palm of the hand. Wrist in extension and without
displacement of the body over the hand. The radius
sustains compression force on the volar cortex and
tensile forces on the dorsum
2. Forced flexion where direct compression stress on volar
cortex combined with traction exerted by the dorsal
ligament

33. BIOMECHANICS OF IMPLANTS
LIGAMENTOTAXIS:
It is the principle of molding fracture
fragments into allignment as a result of tension applied
across a fracture by the surrounding intact soft tissues.it
neutralises the axial load placed on the distal radius by
physiological activity of forearm musculature

34. OPEN REDUCTION AND INTERNAL FIXATION
Dorsal plating:
The fixation is on the compression side of the
fracture and provides a buttress against collapse.A. buttress
plate applies a force to the bone which is
perpendicular(normal) to the flat surface of the plate

35. Volar non locked plating—the primary indication is shear
fracture of the volar lip. It may be unable to maintain fracture
reduction in the presence of dorsal comminution
Volar locked plating---it has been shown to stabilize distal
radius fracture with dorsal comminution
K-WIRE FIXATION:generally used to supplement short
arm casting and for achieving palmar tilt in uniplanar
ligamentotaxix

36. THANK YOU