Skeleton and long tendons of the hand Flashcards
What are the carpal bones?
Scaphoid -> tubercle, Lunate, Trapezium -> tubercle, Pisiform -> in FCU, Trapezoid, Triquetrium, Capitate, Hamate -> hook of hamate.
What is the clinical significance of the carpal bones?
Fracture of scaphoid common -> slow recovery, poor blood supply to proximal part: avascular necrosis.
Where is the wrist (radiocarpal) joint?
Between radius + disc and 1st carpal row
The radiocarpal joint is reinforced by which ligaments?
Ulnar + radial collateral ligaments -> limits abduction / adduction.
Ligaments on palmar/dorsal surfaces (limits extension / flexion).
Origin: styloid processes of radius / ulna. extend to either tubercle on scaphoid or triquetral bones.
What are the movements of the radiocarpal joint?
Flexion/extension, abduction/adduction, circumduction
What type of joint is the carpometacarpal joint and what are its movements?
Plane joints -> limited movement.
Except for saddle joint between trapezium + metacarpal of d1 -> enables opposition.
Extension, flexion, abduction, adduction, opposition, reposition.
What type of joint is the metacarpophalangeal joint and what are its movements?
Condylar joints
Flexion/extension, abduction/adduction
Deep transverse metacarpal ligaments -> unifies metacarpals, not between d1 + 2
What are the interphalangeal joints, its type and its movements?
Hinge, flexion/extension.
Proximal interphalangeal joint -> PIPs
Distal interphalangeal joint -> DIPs.
What is the palmar aponeurosis and what is it continuous with and what is its clinical significance?
Thickened deep fascia, triangular
Continuous with palmaris longus
Forms longitudinal + transverse fibres
Dupuytren’s contracture
What are the long flexor tendons, which digits do they pass to and which structures is it associated with?
From muscles in anterior forearm Pass through carpal tunnel Flexor digitorum superficialis pass to d2-5 Flexor digitorum profundus (d2-5) Flexor pollicis longus (d1) Synovial sheaths surround tendons Flexor retinaculum (transverse carpal ligament) -> prevents bowing of tendons. Median nerve
What are the flexor tendon insertions and which structures are found underneath?
Fibrous digital sheaths -> formed of alternating fibrous annular (A1-A5 pulley’s) + cruciate ligaments.
Synovial sheath
Tendons of flexor digitorum superficialis + profundus for each digit.
Flexor digitorum superficialis -> heads towards PIP, inserts to base of middle phalanx. flexes wrist, metacarpophalangeal joints + PIPs.
Flexor digitorum profundus -> inserts to base of distal phalanx. flexes wrist, metacarpophalangeal joints, PIPs + DIPs of digit that it’s inserting.
(Vinculae attach tendons to phalanges).
What are the long extensor tendons associated with digits 2-5?
Extensor digitorum
Extensor indicis
Extensor digit minimi
What are the long extensor tendons associated with digit 1?
Extensor pollicis longus
Extensor pollicis brevis
Abductor pollicis longus
What is the insertion of the extensor digitorum and what is the function of the extensor hood?
Medial band (into middle phalanx) Lateral band (into distal phalanx) Tendons of extensor digitorum extend wrist, metacarpophalangeal joint (d2-5) and proximal + distal interphalangeal joints (d2-5). Extensor hoods -> attachment for intrinsic muscles.
