Wrist joint Bones taking part
Proximally
Table of Contents
- The distal articular surface of the radius, and
- Articular disc of inferior radioulnar joint.
Distally
- Scaphoid, lunate, triquetral bone, and
- Interosseous ligament.
In the neutral position of the wrist, only the scaphoid and lunate are in contact with the radius and articular disc. The triquetrum comes in contact only in full adduction of the wrist joint.
Read And Learn More: Anatomy Notes And Important Question And Answers
Wrist joint Classification
Structural ABS
- Axis: Biaxial
- The number of bones is 4, forming a compound joint
- Shape: Ellipsoid variety of synovial joint
Functional: Diarthrosis.
Wrist joint Ligaments
1. Capsule
Attachments
Proximally: It is attached close to the peripheral margin of the inferior surface of a distal end of
- Radius and
- To the margins of the articular disc, and
- Styloid process of the ulna.
Distally: It is attached to the proximal surface of
- Scaphoid,
- Lunate, and
- Triquetral.
The capsule is thickened to form by following ligaments
- Palmar radiocarpal,
- Palmar ulnocarpal,
- Dorsal radiocarpal,
- Radial collateral, and
- Ulnar collateral.
Features
- It blends with the palmar and dorsal radiocarpal ligaments.
- It is lined by a synovial membrane.
- It is separate from the distal radioulnar and intercarpal joint.
- A recess is present anterior to the articular disc. It ascends close to the styloid process of the radius. It is called recessus sacciformis.
2. Radial collateral ligament: It is the thickening of the lateral part of the capsule. It extends from the styloid process of radius to the scaphoid and trapezium.
3. Ulnar collateral ligament: It extends from styloid process of ulna to the triquetral and pisiform bone.
Wrist-joint Relations
1. In front: The tendons are arranged in three groups (from lateral to medial). They are
Superficial
- Flexor carpi radialis,
- Palmaris longus, and
- Flexor carpi ulnaris.
Intermediate
- Radial artery,
- The median nerve, and
- Flexor digitorum superficialis (MR)
(Tendons of middle and ring fingers are arranged superficially and tendons of index and little fingers are arranged deeply).
Deep: Flexor pollicis longus, anterior interosseous vessels and nerve, flexor digitorum profundus.
2. Behind: Beneath the extensor retinaculum, there are 6 osseofibrous compartments. These are arranged from lateral to medial as
1st compartment
- Abductor pollicis longus
- Extensor pollicis brevis
2nd compartment
- Extensor carpi radialis longus
- Extensor carpi radialis brevis
3rd compartment
- Extensor pollicis longus
- Tubercle of Lister
4th compartment
- Extensor digitorum and
- Extensor indicis,
- Posterior interosseus nerve, and
- Anterior interosseus artery.
5th compartment: Extensor digiti minimi
6th compartment: Extensor carpi ulnaris.
Wrist joint Movements
1. Movements of the wrist joint are associated with movements of midcarpal joint because they are produced by the same group of muscles.
2. Combination of the wrist and mid-carpal joints is called the link joint.
Joint Movements (READ)
- Radiocarpal: Extension and Adduction.
- In the Radiocarpal joint, the movements are Extension and Adduction.
- Midcarpal: Flexion and abduction.
- In the mid-carpal joint, the movements opposite to the radiocarpal occur.
Muscles bring movements
Wrist joint Blood supply
1. Palmar carpal arch, and
2. The dorsal carpal arch which is derived from
- Anterior interosseous artery,
- Posterior interosseous artery,
- Anterior carpal (branch of radial and ulnar arteries),
- Posterior carpal (branch of radial and ulnar arteries), and
- Recurrent branches of a deep palmar arch.
Wrist joint Nerve supply
- Anterior interosseous nerve (branch of the median nerve), and
- Posterior interosseous nerve (branch of radial nerve).
Wrist joint Applied Anatomy
Colles’ fracture (dinner fork deformity)
- It is due to fall on an outstretched hand,
- It involves the distal end of the radius,
- Here fracture is transverse,
- Force displaces the lower segment upwards and backwards, and
- The distal articular surface is inclined posteriorly.
1. Cause, site, age group and clinical manifestations of Colles’ fracture by “D”
2. Site: It is a fracture of the Distal part of the radius.
3. Cause: It is due to a fall on an outstretched hand.
4. Age-ElDerely due to osteoporosis
5. Manifestations:
- It presents as Dorsally Displaced hand,
- Dorsally angulated
- Physical examination shows a Deformed Dinner fork hand.
- The patient has tenderness at the Distal part of the forearm.
6. Treatment:
- In stable condition, closed reDuction and cast.
- In unstable conditions, open reduction with internal fixation.
- Closed reduction with percutaneous pinning.
Smith’s fracture: It is the reverse of Colles’ fracture:
- It is produced by a fall on the back of the hand.
- Here distal fragment is displaced forward and upward.
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