wrist and hand Flashcards
What are the bones in the carpal proximal row?
Scaphoid, lunate, triquetrum, pisiform
These bones form the proximal row of the wrist.
What are the bones in the carpal distal row?
Hamate, capitate, trapezoid, trapezium
These bones form the distal row of the wrist.
What are the three regions of the scaphoid?
Distal pole, proximal pole, waist
The proximal pole is poorly vascularized, leading to potential necrosis.
What is the significance of the lunate in the wrist?
Important stabilizer of carpus, very little movement
It is vulnerable to avascular necrosis (Kienbock’s disease).
What are the anatomical features of the hamate?
Proximal pole, hook, and body
It is the site of attachment for the flexor retinaculum.
What is the shape of the trapezium bone?
Saddle-shaped at the base of the thumb
It contributes to the anterior orientation of the thumb with the scaphoid.
What is the largest carpal bone?
Capitate
It is located at the base of the long finger.
What does the trapezoid bone provide for the index finger?
Stable base, important for pinch
It supports the functionality of the index finger.
Which bone is a sesamoid bone in the carpal structure?
Pisiform
It articulates with the triquetrum.
What are the types of wrist joints?
Distal radio-ulnar joint, radio-carpal joint, mid-carpal joint
These joints facilitate various movements of the wrist.
What is the primary function of the distal radioulnar joint?
Pronation and supination
It facilitates load transmission between the radius and ulna.
What are the functions of the Triangular Fibrocartilage Complex (TFCC)?
- Stabilization of DRUJ and ulnar side of carpus
- Cushions ulna on carpus
- Allows axial loading of ulna on forearm
- Increases articular surface of carpus
It includes structures like the dorsal and palmar radioulnar ligaments and the ECU.
What are the intrinsic ligaments responsible for wrist stabilization?
Scapholunate and lunotriquetral ligaments
They have a transverse orientation and are critical for stability.
What is the Terry Thomas sign indicative of?
Scapholunate rupture
It presents as a space between the lunate and scaphoid, resembling a missing tooth.
What happens when the scapholunate ligament is injured?
Makes clicking sound when moving, requires surgery
It indicates a complete rupture with potential capitate collapse.
What do extrinsic ligaments do in wrist stabilization?
Connect carpals to radius or ulna, stabilize carpus during extension
Volar ligaments are stronger than dorsal ligaments.
What is the center of rotation of the hand?
Capitate
It plays a crucial role in hand movements.
What occurs during wrist flexion?
Distal and proximal carpal rows both move in flexion
They act like two cylinders rolling in the same direction.
Which metacarpals have greater mobility?
Ring and little finger metacarpals
Their mobility allows for greater hand function.
What are the finger joints?
MCP, PIP, and DIP
Each joint has distinct movement capabilities.
What are the characteristics of the thumb CMC joint?
Saddle joint, allows flexion/extension, abduction/adduction, circumduction, opposition
It is crucial for hand function.
What is Gamekeeper’s thumb?
Torn ulnar collateral ligament at MCP
It allows the thumb to move radially without restriction.
What is the role of the flexor retinaculum?
Prevents bowstringing of flexor tendons, maintains carpal arch
If compressed, it can lead to carpal tunnel syndrome.
What is DeQuervain’s Tendonitis?
Inflammation of the 1st dorsal compartment of extensor retinaculum
Affects abductor pollicis longus and extensor pollicis brevis.
