Wrist and Ankle

Question 1

Joints of forearm, wrist and hand

Accepted Answer

1. Forearm a) Distal radioulnar joint and interosseous membrane - articulation between the head of the ulna and the ulnar notch of the radius - seperation from the radiocarpal joint by a fibrocartilaginous disc - surrounded by a loose fibrous capsule and synovial membrane 2. Wrist a) Radiocarpal (wrist) joint - synovial ellipsoid joint between the concave distal radius and the convec scaphoid, lunate and triquetrum - fibrous capsule and a fibrocartilaginous disc between the head of the ulna and the carpal bones - Stability: laterally and medially by radial and ulnar collateral ligaments, anteriorly and posteriorly by palmar and dorsal ligaments 3. Hand a) Midcarpal and Intercarpal and carpometacarpal joints - Midcarpal between the prox. and distal row of carpal bones (Flexion/Extension; Abduction/adduction) - Intercarpal between all carpal bones (plane synovial joints) - Carpometacarpal between the distal carpal bones and the metacarpals (plane synovial joints) --> Carpometacarpal joint of the thumb (synovial saddle joint) - between trapezium (saddle shape) and 1st metacarpal allowing Abduction/Adduction, Flexion/Extension and Opposition - Metacarpophalangeal (synovial ellipsoid joint of 2nd-5th finger) --> Flexion/Extension, Abduction/Adduction - Interphalangeal (synovial hinge joints)

Question 2

Joints of the leg, ankle and foot

Accepted Answer

1. Leg a) Proximal tibiofibular joint - synovial plane gliding joint between the head of the fibula and the lateral tibial condyle b) Distal tibiofibular joint - fibrous syndesmosis joint between the fibular notch of the tibia and the fibula --> strong c) Interosseous membrane - unites tibia and fibula - seperation of muscles into anterior and posterior compartments - provides attachment for muscles 2. Ankle - the ankle joint includes three joints: talocrural joint (proper ankle joint), subtalar joint, inferior tibiofibular joint - synovial hinge joint between the distal tibia, the two malleoli and the body of the talus - joint capsule weak anteriorly and posteriorly + synovial membrane - Stability: Medial (deltoid) collateral ligament (medial malleolus - talus, calcaneus, navicular), Later collateral ligament (lateral mallelolus - talus, calcaneus) --> Lateral ligament is weaker, most ankle sprains involve it 3. Foot a) Intertarsal joints - subtalar (talocalcaneal), talocalcaneonavicular, calcaneocuboid --> their gliding produces eversion/inversion of the foot --> Stability: talocalcaneal ligament (talus - calcaneus), dorsal and plantar ligaments, calcaneoclavicular ligament/Spring ligament(calcaneus - navicular), Long and short plantar ligament (calcaneus - cuboid) b) Tarsometatarsal c) Intermetatarsal d) Metatarsophalangeal e) Interphalangeal

Question 3

Muscles of the forearm

Accepted Answer

1. Anterior department a) Superficial layer (medial -> lateral) - Flexor carpi ulnaris (Med.epicondyle - Pisiform) --> Flexion+Adduction (wrist) --> Ulnar nerve - Palmaris longus (Med.epicondyle - palmar apaneurosis) --> Flexion (Wrist) --> Median nerve - Flexor carpi radialis (Med.epicondyle - 2nd/3rd metacarpal) --> Flexion+Abduction(wrist) --> Median nerve - Pronator teres (med.epicondyle - lat.radius) --> Pronation --> Median nerve b) Intermediate layer - Flexor digitorum superficialis (Med.epicondyle+surface radius - middle phalanges of 2nd-5th digit) --> Flexion (prox.interphalangeal joint, metacarpophalangeal joint,wrist) --> Median nerve c) Deep layer (medial -> lateral) - Flexor digitorum profundus (Anterior ulna - distal phalanges of 2nd-5th digit) --> Flexion (interphalangeal joint, metacarpophalangeal joint, wrist) --> Median+Ulnar nerve - Flexor pollicis longus (Ant. radius - distal phalanx thumb) --> Flexion (thumb+wrist) --> Median nerve 2. Posterior compartment a) Superficial layer (lateral -> medial) - Brachioradialis (lat.supracondylar ridge - styloid process radius) --> Flexion(elbow) --> Radial nerve - Extensor carpi radialis longus (Lat.supracondylar ridge - 2nd metacarpal) --> Extension+Abduction(wrist) --> Radial nerve - Extensor carpi radialis brevis (Lat-epicondyle - 3rd metacarpal) --> Extension+Abduction (wrist) --> Radial nerve - Extensor carpi ulnaris (Lat.epicondyle - 5th metacarpal) --> Extension+Abduction (wrist) --> Radial nerve - Extensor digitorum (lat.epicondyle - dist.phalanges digits 2-5) --> Extension (phalanges+wrist) --> Radial nerve - Extensor digiti minimi (Lat.epicondyle - dist.phalax little finger) --> Extension (wrist+little finger) --> Radial nerve --> All extensor are supplied by the posterior interosseous nerve (branch of radial nerve) b) Deep layer (lateral -> medial) - Abductor pollicis longus (post.radius+ulna - 1st metacarpal) --> Abduction+Extension (thumb) --> Radial nerve - Extensor pollicis brevis (post.ulna+radius - prox.phalanx thumb) --> Extension (thumb) - Extensor pollicis longus (post. ulna - dist.phalanx thumb) --> Extension (thumb) --> Radial nerve - Extensor indicis (post.ulna - 2nd phalanx) --> Extension (Index finger+wrist) --> Radial nerve

Question 4

Muscles of the leg

Accepted Answer

1. Posterior compartment a) Superficial layer - Gastrocnemius muscle (Med./Lat.epicondyle - calcaneus) --> Plantarflexion, Inversion, Flexion(knee) - Soleus muscle (prox.tibia+fibula - calcaneus) --> Plantarflexion, Inversion - Plantaris muscle (Lat.epicondyle - Calcaneus) b) Deep layer - Flexor hallucis longus (middle fibula - along med. foot to dist.phalanx toes) --> Plantarflexion, Flexion (toe) - Flexor digitorum longus (middle tibia - along med. foot with 4 tendons to dist.phalanges 2-5) --> Plantarflexion, Flexion (toes) - Popliteus muscle (lat.epicondyle - med.tibia) --> Unlocking of the knee - Tibialis posterior (tibia/fibula/interosseous membrane - along med. foot to plantar surface to Navicular/med.cuneiform) --> Inversion --> All innervated by tibial nerve 2. Anterior compartment - Extensor hallucis longus (middle fibula - base dist.phalanx hallux) --> Dorsiflexion, Extension (toe) - Extensor digitorum (tibia/fibula/interosseous membrane - digits 2-5) --> Dorsiflexion, Extension (digits 2-5) - Tibialis anterior (lat.tibia - along med.foot to med.cuneiform+1st metacarpal) --> Dorsiflexion - Peroneus tertius (inferior anteromedial fibula - 5th metatarsal) --> Eversion --> all innervated by deep peroneal nerve 3. Lateral compartment - Peroneus longus (head fibula - along lateral malleolus to plantar surface and 1st metatarsal) --> Plantarflexion, Eversion - Peroneus brevis (middle fibula - behind lat.malleolus to 5th metatarsal) --> Eversion, Plantarflexion --> innervated by superficial peroneal nerve

Question 5

Anatomical spaces - carpal tunnel

Accepted Answer

- anterior aspect of the wrist 1. Borders - flexor retinaculum 2. Contents - four tendons of flexor digitorum profundus and flexor digitorum superficialis - Tendon of Flexor carpi radialis - Tendon of Flexor pollicis longus - Median nerve 3. Syndromes - swelling deep to the flexor retinaculum (e.g. synovitis) can lead to compression on the median nerve --> carpal tunnel syndrome

Question 6

Anatomical spaces - anatomical snuffbox

Accepted Answer

- lateral dorsal aspect of the wrist 1. Borders - Lateral = tendons of extensor pollicis brevis and abductor pollicis longus - Medial = tendon of extensor pollicis longus - Floor = Scaphoid bone 2. Contents - radial artery - cutaneous branches of the radial nerve

Question 7

Innervation of forearm

Accepted Answer

1. Ulnar nerve - arises from the spinal root values C7-T1 from the medial cord of the brachial plexus a) Muscle innervation - Anteromedial muscles of the forearm and hand: Flexor carpi ulnaris, Flexor digitorum profundus, Hypothenar muscles, interosseous muscles and medial lumbricals b) Sensory - Medial aspect of hand and medial 1,5 digit --> Dermatome C8 2. Median nerve - arises from the spinal root values C5-T1 from the lateral and medial cords of the brachial plexus a) Muscle innervation - muscles of anterior compartment of the forearm: - Pronator teres,Palmaris longus, flexor carpi radialis, flexor digitorum superficialis - Thenar and lumbrical muscles (1+2) - Anterior interosseous nerve: Flexor digitorum profundus, flexor pollicis longus, pronator quadratus b) Sensory - Lateral hand and lateral 3,5 digits - Palmar cutaneous branch: Thenar eminence --> Dermatomes C6,C7

Question 8

Innervation of the leg

Accepted Answer

1. Tibial nerve - spinal root values L4-S3, lies in the popliteal fossa - divides into the medial and plantar nerves of the foot (behind medial malleolus) a) Muscle innervation - Muscles in the posterior compartment of the leg and foot: Popliteus,Gastrocnemius, Soleus, Plantaris, Flexor digitorum longus, Flexor hallucis longus - Via Medial and plantar nerves: muscles at the sole of the foot b) Sensory - Medial and lateral aspects of the sole of the foot (med.+lat. plantar nerve) --> Dermatomes L4,L5,S1 2. Common peroneal nerve, Superficial & Deep peroneal nerve - spinal nerve values L4-S2, emerges from the sciatic nerve, curves posteriorly around the head of the fibula to lie anteriorly where it divides into the deep and superficial peroneal nerve a) Superficial peroneal nerve - Muscles: lateral compartment of the leg: Peroneus longus, peroneus brevis - Sensory: anterolateral distal 1/3 of leg + dorsal surface of foot --> Dermatome L5/S1 b) Deep peroneal nerve - Muscles: Anterior compartment of the leg and foot: Tibialis anterior, extensor digitorum brevis, extensor hallucis longus, peroneus tertius, Extensor digitorum brevis - Sensory: Adjacent sides of 1st and 2nd toes --> Dermatomes: L5 3. Sural nerve - between tibial nerve and common peroneal nerve - Sensory: lateral ankle and lateral foot --> Dermatome S1,S2

Anatomy (Locomotor) (Fach) / Wrist and Ankle (Lektion)