Flexor Forearm and Palm Flashcards
Four principal movements at radiocarpal joint
- Flexion
- Extensioin
- Adduction/ulnar deviation
- Abduction/radial deviation
Bones of the radiocarpal joint
Distal radius, and scaphoid and lunate bones
Nursemaid’s elbow
Sublixation (partial dislocation) of radio-ulnar joint
- Head of radius displaced from encirclement by anular ligament
Tennis elbow
Lateral epicondylitis
- Inflammation of common extensor tendon of wrist
- Caused by overuse or trauma
Golfer’s elbow
Medial epicondylitis
- Inflammation of common flexor tendon of the wrist (originates at medial epicondyle of humerus)
- Cause is overuse or trauma
Muscles involved in avulsion of medial epicondyle of humerus
Flexors of forearm all have origin on medial epicondyle of humerus
- Pronator teres
- Flexor carpi radialis
- Flexor carpi ulnaris
- Flexor digitorum superficialis
- Palmaris longus
The medial epicondyle has its own growth plate on the humerus which is why it can be involved in avulsion in youth
Structures in anterior wrist that are at risk with wrist cutting
Radial/lateral cuts
- Injure median nerve, radial artery, flexor carpi radialis tendon, and palmaris longus tendon
Ulnar/medial cuts
- Injure ulnar nerve, ulnar artery, and flexor carpi ulnaris tendon
Colle’s versus Smith’s fracture
Colle’s, radius displaced posteriorly
Smoth’s, radius displaced anteriorly
Both occur in FOOSH with children
Mallet/Baseball finger
Injury of extensor digitorum longus tendon at the distal interphalangeal (DIP) joint
- Causes inability to extend the DIP joint (permanently stuck in a little bit of flexion)
Clinical assesment of median nerve
- Oppose thumb
- Make OK sign
- Forearm pronation (and resist supination)
- Wrist flexion
Clinical assesment of anterior interosseous nerve branch
Branch of median nerve in cubital fossa (motor, not sensory)
Clinical assesment
- Cannot touch tips of fingers together (can only do pads)
- Localized pain in forearm but no sensort loss
Carpal tunnel syndrome and treatment
Compression of median nerve due to inflammation of transverse carpal ligament/flexor tendons
- Pain and tingling in lateral half of hand
Treatment involves surgery where you cut the transverse carpal ligament to “release” the pressure on the median nerve
10 structures going through the carpal tunnel
- Median nerve
- Flexor pollicus longus tendon
- Flexor digitorum profundus tendons (4)
- Flexor digitorum superficialis tendons (4)
Tendons through ulnar bursa (common flexor sheath)
Tendons of flexor digitorum superficialis and flexor digitorum profundus
Tendons through radial bursa
Tendons of flexor pollicis longus
Thenar muscles
- Abductor pollicis brevis
- Flexor pollicis brevis
- Opponens pollicis
All innervated by recurrent median nerve
Hypothenar muscles
- Abductor digit minimi
- Flexor digiti minimi brevis
- Opponens digiti minimi
All innervated by deep branch of ulnar nerve
Volkmann ischemic contracture
Deformity of wrist, fingers, and hand caused by injury to muscles of the forearm
- Ischema due to obstruction of brachial artery, compartment syndrome, or supracondylar fracture of humerus
- Prolonged ischemia leads to muscle and nerve damage leading to shortened, fibrotic muscle fibers
- The shortened muscles pull on joint but the joint is stiff so you get contracture
Flexor digitorum profundus (and sometimes pollicis longus) are effected
Dupuytren’s contracture
Painless thickening and fibrosis of palmar fascia
- Etiology is unknown
- Affects both hands symmetrically and causes progressive fixed flexion deformity of MCP joints, PIP joints, but rarely DIP joints
