1. Anatomy of wrist and Hand 1
Assistant professor
Dr. Alaa A. Alharba
Orthopedic &Hand Surgeon

2. The Hand as a Functional Unit

3. At the distal end of the upper limb is the important prehensile organ __ the Hand.
The hand is the primary means through which human beings physically interact with the environment around them.
Much of the importance of the hand depends on the pincer action of the thumb, which enables us to grasp objects between the thumb and index finger. The extreme mobility of the first metacarpal bone makes the thumb functionally as important as all the remaining four fingers combined.

4. The hand serves three basic functions:
Sensory perception: in the form of pain, light touch, vibration, temperature recognition, and proprioception
Pincer function: (precise function).
Power grip: (making a fist). Fist is made by flexing the MCP joints and IP joints with extension of the wrist. Making a ‘strong fist’ with the wrist flexed is very difficult.

5. The hand has two basic positions:
(a) Position of rest (relaxation): wrist and fingers are in flexion position.
(b) Position of function: the wrist extended, fingers in flexion, and the thumb in opposition. This slight wrist flexion make the long flexor and extensor tendons of the fingers are working to their best mechanical advantage.

6. Bones:
There are 8 CARPAL BONES made up of two rows of four:
Proximal( lat. to med.): scaphoid, lunate, triquetral, and pisiform.
Distal: trapezium, trapezoid, capitate, and hamate.

7. Bones:
Metacarpals:
There are five metacarpal bones each of which has a base, shaft, and head. The first metacarpal of the thumb is the shortest and most mobile, it does not lie in the same plane as the others but occupies a more anterior position.
The bases of metacarpal bones articulate with the distal row of the carpal bones, while the heads articulate with the proximal phalanges

8. Bones:
Phalanges:
There are three phalanges for each finger, but only two for the thumb.

9. Joints of the Hand and Fingers

10. Intercarpal Joints:
Articulation between the individual bones of the proximal carpal row ; between the individual bones of the distal carpal row; and finally, the midcarpal joint: between the proximal and distal carpal rows.
Ligaments: the carpal bones are united by strong anterior, posterior, and interosseous ligaments.

11. Intercarpal Joints: Capsule: it surrounds each joint.
Synovial membrane: it lines the capsule and attached to the margins of the articular surfaces. The joint cavity of midcarpal joint extends between the two rows and between the individual bones forming the proximal ad distal rows.
They are plane synovial joints allow a small gliding movement.

12. Carpometacarpal joint of the Thumb
It is an articulation between the base of the first metacarpal and the trapezium.
It is synovial saddle joint.
It allows flexion, extension, adduction, abduction, and rotation (opposition).
Other carpometacarpal joints are plane joints.

14. Metacarpophalangeal (MCP)Joints:
It is an articulation between the head of metacarpal bone and the base of the proximal phalanx. They are synovial condyloid joints allow flexion, extension, abduction and adduction ( except in the thumb the adduction and abduction are in the carpometacarpal joint).

15. Metacarpophalangeal Joints:
Ligaments:
The collateral ligaments: are cord-like bands present on each side of the MCP joints. These ligaments are lax in extension allow abduction and adduction of fingers, and become taut in flexion making abduction and adduction more difficult.
Capsule: surronds the joint.
Synovial membrane: lines the capsule and is attached to the margins of the articular surfaces.

16. Interphalangeal Joints
They are synovial hinge joints that have structure similar to that of the metacarpophalangeal joints. There are proximal (PIP) and distal (DIP) joints.

17. The Palm of the Hand

18. Skin of the palm
It is thick and hairless. It is bound down to the underlying deep fascia by numerous fibrous bands. The skin show many flexure creases at the sites of skin movement, which are not necessarily placed at the site of joints. Sweet glands are present in large numbers.

19. Hand Skin Creases:
Proximal and Distal flexion creases of fingers: mark the approximate locations of PIP & DIP joints respectively.
Web flexion creases: at the level of midpoint of the proximal phalanges.
Proximal & Distal transverse palmar flexion creases: cross the palm transversely mark the level of MCP joints.
Longitudinal interthenar crease.
Proximal & distal wrist creases
DIP
PIP
Web crease 3 4 5

20. The Palm of the Hand: Skin:
Nerve Supply: the sensory supply of palm skin are:
Palmar cutaneous branch of the median nerve: supplies the lateral aspect of the palm.
palmar cutaneous branch of the ulnar nerve: supplies the medial aspect of the palm.
Deep Fascia:
Is thickened to form the flexor retinaculum and palmar aponeurosis