NAIHS Rishi Pokhrel joints forearm wrist radioulnar

1. JOINTS OF FOREARM
MAJ RISHI POKHREL
NAIHS
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2. • Carpel tunnel syndrome?

3. • Radioulnar joints
• Proximal
• Distal
• Intermediate
• Wrist Joint

4. Joint
• Introduction
• Articulating surfaces
• Ligaments
• Synovial membrane
• Special feature e.g. disc, meniscus
• Blood supply & innervation
• Movements & muscles
• Applied

5. Proximal Radioulnar Joint
• Type: Uniaxial pivot joint.
• Articulating surfaces
– Circumference of the radial head
– Fibro-osseous ring formed by
ulnar radial notch & annular
ligament

6. Ligaments
• Fibrous capsule
– continuous
with that of
elbow joint &
attached to
the annular
ligament

7. Ligaments
• Annular ligament
– Strong band, 4/5th of ring
– Encircles the radial head, holding it against radial notch of the
ulna.
– Attached to anterior margin of the notch and rough ridge at or
behind the posterior margin of the notch

8. Ligaments
• Quadrate ligament
– thin, fibrous
– stretches between neck of the radius & upper part
of the supinator fossa of the ulna
– covers the synovial membrane on the distal
surface of the joint
– maintains constant tension throughout pronation
and supination.

11. Synovial membrane
• continuous with that of elbow
joint
• Covers proximal radio-ulnar joint
& elbow joint as 1 synovial cavity
• Prevented from herniation
between anterior & posterior free
edges of the annular ligament by
the quadrate ligament

12. Vascular supply
Periarticular anastomosis around elbow joint

13. Innervation
• Small branches from
– Musculocutaneous
– Median
– Radial
– Ulnar
• Hilton’s law

14. Factors maintaining stability
• Prime stabilizing factor - annular ligament
• Encircles the radial head and holds it against
the radial notch of the ulna

15. Applied anatomy
• Pulled elbow
• Subluxation of the radial head through annular
ligament arising from a sudden jerk
• common injury in young children
• annular ligament has vertical sides in children
compared with more funnel-shaped sides in
adults
• Reduction by forcefully supinating and flexing
elbow which snaps the ligament back into place.

18. Distal Radioulnar Joint
• Uniaxial pivot joint
• Articulating surfaces
– convex distal head of ulna & concave ulnar notch
of the radius
– connected by an articular disc.

19. Ligaments
• Fibrous capsule
– Thicker anteriorly and posteriorly
– Proximal part of the capsule is lax.

20. • Articular disc
– Fibrocartilaginous
– Binds distal ends of ulna &
radius
– Thick periphery, centre thin
or sometimes perforated.
– Triangular in shape
– Apex attached to depression
between styloid process and
distal articular surface of ulna
– Base attached to prominent
edge between ulnar notch
and carpal articular surface of
the radius

21. Synovial membrane
• Projects proximally between radius & ulna - ‘recessus
sacciformis’ in front of distal part of the interosseous
membrane
• Does not communicate with wrist joint

22. • Blood supply
– palmar and dorsal br of the ant interosseous A
with post interosseous & ulnar A
• Innervation
– Branches of ant & post interosseous N

23. Intermediate Radioulnar Joint
• Interosseous membrane
• Type: Syndesmosis type of
Fibrous joint

24. Movements
• Pronation
– Pronator quadratus
– pronator teres
• Supination
– Supinator
– Biceps brachii

26. Wrist / Radiocarpal jt
• Type: synovial, biaxial,
ellipsoid
• Articulating surfaces:
– distal end of radius &
triangular fibrocartilage
– scaphoid, lunate and
triquetral

28. Ligaments
• Fibrous capsule
• Palmar radiocarpal & ulnocarpal
• Dorsal radiocarpal
• Radial and ulnar collateral ligaments

29. • Synovial membrane: lines the fibrous capsule
• Vascular supply
– Ant interosseous A
– Ant & post carpal br of radial and ulnar arteries
– Palmar & dorsal metacarpal A
– Recurrent rami of the deep palmar arch.
• Innervation
– Ant & post interosseous
– median, ulnar & radial N.

30. Movements & muscles

31. Range of movements
• flexion (85°),
• extension (85°),
• adduction or ulnar deviation (45°),
• abduction or radial deviation (15°)
• circumduction

32. Muscles
• Flexion
– FCR, FCU, Palmaris longus
– assisted by FDS, FDP, FPL
• Extension
– ECRL, ECRB, ECU,
– assisted by ED, EDM, EI and EPL
• Adduction
– FCU, ECU
• Abduction
– FCR, ECRL, ECRB,
– abductor pollicis longus and extensor pollicis brevis