Interval 9: Hand and Foot Flashcards
At the wrist, the carpal bones articulate proximally with the radius and ulna at the _______ and _______ joints and distally with the metacarpals at the __________ joints.
- radio carpal
- ulnocarpal
- carpometacarpal
What forms the radiocarpal joint?
-distal end of the radius and the scaphoid and lunate
What forms the ulnocarpal joint?
-distal end of ulna, an articular disk, and the triquetrum
What movements do the radiocarpal and ulnocarpal joints permit?
-flexion, extension, abduction (radial deviation) and adduction (ulnar deviation)
Colles’ fracture
- fracture of the distal end of the radius resulting from a fall on the outstretched hands
- posterior placement of distal surface producing “dinner fork” deformity
Colles’ facture usually occurs in what patient population?
-patients older than 50
Name the proximal and distal carpal bones from lateral to medial
- scaphoid
- lunate
- triquetral
- pisiform
- trapezium
- trapezoid
- capitate
- hamate
The pisiform is really a sesamoid bone in the tendon of the _________.
-flexor carpi ulnaris
Any bone prominens on the proximal row of carpal bones?
-scaphoid tubercle
What is unique about the trapezium?
-characterized by an elongated tubercle on its palmar surface that the tendon of the flexor carpi radialis passes through
What is the largest carpal bone?
-capitate
The hamate is characterized by its flattened, hook like process, the _______.
-Hamulus
What is the most commonly dislocated carpal bone? What issues may arise from this?
- lunate
- typically dislocated anteriorly into the carpal tunnel
- dislocation may cause carpal tunnel syndrome
What forms the arch of the carpal tunnel?
-the flexor retinaculum
Describe the ulnar and radial attachments of the flexor retinaculum.
- ulnar proximal: pisiform
- ulnar distal: hook of hamate
- radial proximal: tubercle of scaphoid
- radial distal: medial side of trapezium
Contents of the carpal tunnel
- tendons of the flexor pollicis longus and its own synovial sheath
- tendons of the flexor digitorum superficialis
- tendpns of flexor digitorum profundus
- median nerve
Position of median nerve in the carpal tunnel
-lies superficial to the long flexor tendons against the deep surface of the flexor retinaculum
Where is the canal of Guyon and what passes through it?
- a space on the anterior surface of the flexor retinaculum covered by superficial slip of fascia lateral to pisiform
- ulnar nerve and artery pass through this just lateral to pisiform
In each of the 4 fingers, a metacarpal and the 3 phalanges form what 3 joints?
- metacarpophalangeal joint (MP joint)
- proximal interphalangeal joint (PIP joint)
- distal interphalangeal joint (DIP joint)
Metacarpophalangeal joints allows movement in what direction?
- flexion-extension
- abduction-adduction
- condyloid joints
What movements do the phalangeal joints permit?
- flexion and extension
- they are hinge joints
Insertion of flexor carpi ulnaris
-pisiform
At the PIP joints the ______ phalanges articulate with the ________ phalanges. At the DIP joints, the ______ phalanges articulate with the ________ phalanges.
- proximal; middle
- middle; distal
3 joints of the thumb
- carpometacarpal joint
- MP joint
- interphalangeal joint
What type of joint is the carpometacarpal joint of the thumb and what actions does it permit?
- saddle joint formed by first metacarpal and the trapezium
- flexion, extension, abduction, adduction, and rotation
Borders of the anatomical snuffbox
- lateral: extensor pollicis brevis and abductor pollicis longus
- medial: extensor pollicis longus
- floor: scaphoid and trapezium bones
The ________ travels through the snuffbox, and the ______________ innervates skin over the snuffbox
- radial artery
- superficial branch of the radial nerve
What is the most commonly fractured carpal bone? Signs exhibited in patients?
- scaphoid
- pain and tenderness localized over anatomic snuffbox
Avascular necrosis and the scaphoid
-proximal part may undergo avascular necrosis because the blood supply to the bone supplies the distal part first and then the proximal part
The wrist is an ________ joint conveying what movements?
- ellipsoid joint
- flexion, extension, abduction, adduction, and circumduction
Can the wrist rotate?
-no, but supination and pronation in the forearm compensate for this inability
___________ arise from the brachial artery in the cubital fossa and supply the forearm and the hand.
-Radial and ulnar arteries
The common interosseous artery arises from the __________ in the cubital fossa. What does it branch into and supply?
- ulnar artery
- branches into anterior and posterior interosseous artery which supplies deep muscles in anterior and posterior forearm
The ulnar artery and its branches supply ______.
-the medial side of the forearm and hand
Superficial arch
-continuation of the ulnar artery which forms the superficial palmar arch in the palm of the hand and branches into palmar metacarpal arteries which supply the hand and digits
Deep branch of the ulnar artery
-anastomoses with the medial part of the deep palmar arch
What does the radial artery supply?
-lateral side of the forearm and the hand
Superficial branch of the radial artery
- arises from radial artery at wrist
- anastomoses with lateral part of the superficial palmar branch
Distal part of the radial artery
- courses dorsal to the wrist and crosses the floor of the anatomic snuffbox
- enters the deep part of the palm after passing between the 2 heads of the first dorsal interosseous muscle
- forms the deep palmar arch that branches into dorsal metacarpal arteries, which supply the hand and digits
5 muscles/groups of muscles that are intrinsic to the hand
- adductor pollicis
- thenar muscles
- hypothenar muscles
- interossei
- lumbricals
Unlike the extrinsic muscles that originate in the forearm, insert in the hand, and function in forceful gripping, the intrinsic muscles _______.
-occur entirely in the hand and mainly execute precision movements with the fingers and thumb
All intrinsic muscles are innervated by the _________ EXCEPT for _________.
- deep branch of the ulnar nerve
- EXCEPT the three thenar muscles and 2 lateral lumbricals
3 thenar muscles and 2 lateral lumbricals are innervated by ______.
-median nerve
Name the muscles of the thenar compartment and their innervation
- abductor pollicis brevis
- flexor pollicis brevis
- opponens pollicis
- innervated by recurrent branch of the median nerve
Abductor pollicis brevis function and innervation
- abduction of the thumb at metacarpophalangeal joint
- recurrent branch of median nerve
Flexor pollicis brevis function and innervation
- flexion of thumb
- recurrent branch of median nerve
Opponens pollicis function and innervation
- opposes and flexes the thumb
- recurrent branch of median nerve
Lumbricals arise from and are innervated by what?
- take origin from tendons of the flexor digitorum profundus muscle
- 1st and 2nd lumbricals are innervated by median nerve
- 3rd and 4th by ulnar nerve
Muscles and innervation of hypothenar compartment
- abductor digiti minimi
- flexor digiti minimi brevis
- opponens digiti minimi
- deep branch of ulnar nerve
Abductor digiti minimi function and innervation
- abduction of digit 5 at MP joint
- deep branch of ulnar nerve
Flexor digiti minimi brevis
- flexion of digit 5 at MP joint
- deep branch of ulnar nerve
Opponens digiti minimi
- lateral rotation of metacarpal 5
- deep branch of ulnar nerve
4 muscles of the central compartment and their innervation(s)
- lumbricals: medial 2 by deep branch of ulnar n and lateral 2 by digital branches of the median nerve
- Adductor pollicis: deep branch of ulnar nerve
- Dorsal interossei: deep branch of ulnar nerve?
- Palmar interossei: deep branch of ulnar nerve?
Lumbrical function and innervation
- flex the MP joints and extend the proximal and distal IP joints of digits 2-5
- medial 2: deep branch of ulnar nerve
- lateral 2: digital branches of median nerve
Adductor pollicis function and innervation
- adducts thumb
- innervated by deep branch of ulnar nerve
Dorsal interossei function
- abducts at MP joint, flexes at MP joint, extends at PIP and DIP joints
- DAB* :dorsal abducts
Palmar interossei function
- adducts the MP joint, flexes at MP joint, extends at PIP and DIP joints
- PAD*: palmar adducts
What kind of nerve branches of the radial nerve are found in the hand?
-only sensory; it does not innervate any intrinsic muscles of the hand
As the flexor and extensor tendons pass across the wrist joint, they are all surrounded by synovial sheaths and bound to both the dorsal and palmar aspects of the wrists by ________.
-retinacula
Where does the flexor carpi radialis travel through?
-it has a separate compartment formed by a split of the retinaculum
Which tendons of the palmar wrist are completely covered by synovial sheaths?
- flexor carpi radialis
- flexor pollicis longus
What is the sheath of the flexor pollicis longus called? What is the common flexor sheath for the other fingers called?
- radial bursa
- ulnar bursa
If the radial bursa and ulnar bursa are separate, how can sometimes the inflammation of one lead to pain and inflammation of the other?
-in about 10-15% of people, there is a communication between the radial and ulnar bursae
Although synovial sheaths perform an important function, they also can be negative. Give an example of when this is true.
-they also act as easy pathways for the spread of infection
Palmar fascia also contributes to the spread of infection. What are the 3 compartments the palmar fascia is divided into?
- thenar fascia covering muscles of the thenar compartment
- hypothenar fascia covering muscles of the hypothenar
- palmar aponeurosis, a thickened portion of the deep fascia over the middle compartment
Proximally the palmar aponeurosis is continuous with the ____________. What occurs to it distally?
- flexor retinaculum and palmaris longus muscle
- distally it breaks up into 4 slips that are joined together by superficial metacarpal ligaments. Each slip passes distally to fuse with the fibrous flexor sheath, the capsules of the MP joints and the proximal phalanx
Dupuytren’s contracture
- permanent flexion deformity of ring and little finger
- can be due to hypertrophy and retraction of the palmar aponeurosis, usually to ring and little finger, leading to this permanent flexion deformity involving the MP and PIP joints
Central part of the palm, which lies deep to the flexor aponeurosis and between the thenar and hypothenar compartments, is divided further into 2 fascial spaces by an ___________ from the deep surface of the palmar aponeurosis to the 3rd metacarpal bone. What are the 2 spaces called?
- intermediate palmar septum
- more lateral space is called thenar or adductor space
- more medial space is called the mid-palmar fascial space
Structures found in the thenar vs. midpalmar space
Thenar: flexor pollicis longus, long flexor tendons of the index fingers, and 1st lumbrical
Midpalmar: long flexor tendons of the 3rd, 4th, and 5th fingers and the 2nd, 3rd, and 4th lumbricals
What should be noted about the 2 fascial spaces of the central compartment (thenar and midpalmar space)?
- potential areas for gravitation of pus, blood, or serum after injury or infection in palm and the hand
- require surgical drainage
What can cause infections in the thenar and midpalmar spaces?
Thenar: infections that rupture from tendon sheaths of the index finger and thumb
Midpalmar: purulent tenosynovitis of synovial sheaths of the middle, ring, and little fingers can rupture into midpalmar space
-10-15% of these infections can pass from one space to another
Retrotendinous (subtendinous) space of Parona
-potential space on the palmar surface of the wrist the lies between the tendon of the flexor digitorum profundus and flexor pollicis longus anteriorly, and the pronator quadratus posteriorly
Potential consequence of retrotendinous space of Parona frequently connecting with thenar and midpalmar spaces more distally.
-collections within the palmar spaces may extend proximally into the distal part of the forearm
3 “types” of bones in the foot
- tarsal bones
- metatarsal bones
- phalanges
What is the largest bone of the foot? What does it articulate with?
- calcaneous
- articulates above with the talus and in front with the cuboid bone
The medial surface of the calcenous possesses a large shelflike ridge called the ___________ that assists in the support of the talus.
-sustenaculum tali
What ligament runs between the sustenaculum tali and the navicular?
-spring or plantar calcaneonavicular ligament
What forms the talo-crural (ankle) joint?
-the talus articulating with the tibia and fibula
What forms the subtalar joint?
the talus articulating inferiorly with the calcaneus
What forms the talocalcaneounavicular joint?
-the talus articulating anteriorly with the sustenaculum tali and navicular
Are any muscles attached to the talus?
-no, but many important ligaments are
The navicular possesses a prominent tubercle for the insertion of the main part of the ____________.
-tibialis posterior muscle
The ankle joint includes what 3 joints?
- talocrural joint
- subtalar joint
- transverse tarsal joints
What forms the talocrural joint? What kind of joint is it? What movements does it permit?
- articulation between the trochlea of the talus and the lateral and medial malleoli of the fibula and tibia, respectively
- hinge joint
- dorsiflexion and plantar flexion of the foot
Is the foot more stable in the dorsiflexed or plantar flexed position? Why?
- dorsiflexed position
- the anterior part of the superior surface of the trochlea of the talus is wider than the posterior part of the talocrural joint
Which tendons enter the sole of the foot after passing posterior and inferior to the medial malleolus?
- tibialis posterior
- flexor digitorum longus
- flexor hallucis longus
Which tendons enter the sole of the foot after passing posterior and inferior to lateral malleolus?
- fibularis longus
- fibularis brevis
What 2 ligaments strengthen the talocrucal joint and which is stronger of the 2?
- deltoid (medial) ligament and lateral ligaments
- deltoid is stronger
Deltoid ligament
-has 4 components that extend from the tibia to the talus, navicular, and calcaneous
Lateral ligament
-has 3 components that extend from the fibula to the talus and calcaneous
Are inversion or eversion ankle sprains more common?
-inversion
The __________ part of the lateral ligament is commonly torn in inversion ankle sprains.
-Anterior talofibular lateral ligament (ATFL)
Subtalar joint
- ball and socket joint formed by articulation between the talus and calcaneus
- permits supination and pronation
Describe supination and pronation of the ankle offered by subtalar joint
Supination: plantar flexion, inversion, and adduction
Pronation: dorsiflexion, eversion, abduction
What forms the transverse tarsal joints?
-articulations of the talus with the navicular and calcaneus with the cuboid
What does the transverse tarsal joint contribute to?
-inversion and eversion with the subtalar joint
The sole of the foot contains short abductors and flexors of the great toe and little toe, respectively, but lacks….
-eminences and opponens muscles
Quadratus plantae is a plantar muscle with no counterpart in the hand; what does it do?
-acts to straighten out the oblique pull of flexor digitorum longus tendons
2 arches of the foot
-longitudinal and transverse arches
Longitudinal arch
- comprises tarsus and metatarsus
- medial side is higher than the lateral side
- both of these components share a common posterior pillar, the tuberosity of the calcaneous
The _____ is the keystone of the longitudinal arch and receives the body weight that is then distributes to both components of the arch (lateral and medial). Therefore, where is the body weight distributed?
- talus
- transmitted to the ground through the calcaneus and heads of the metatarsal bones, the 1st taking more weight that the others
2 ways the foot deals with heavy body weight
- arch give foot resilience and ability to change shape
- subcutaneous tissue in weight bearing areas is relatively thick
- numerous loculi of adipose tissue surrounded by fibrous capsules that have a large amount of elastic fibers
What ligaments are thought to be the first line of defense in maintaining the integrity of the arches? What is believed to provide additional support?
- plantar aponeurosis
- plantar calcaneonavicular (spring) ligament
- long and short plantar ligaments in sole
- interosseous ligaments between individual tarsal bones
- extrinsic and intrinsic muscles of the foot (tibialis anterior and posterior, peroneus longus, and flexor hallucis longus)
The principal joint for inversion and eversion is the _____________.
-talocalcaneonavicular articulation
What are the main invertors and evertors of the foot?
- invertors: tibialis anterior and tibialis posterior
- evertors: fibularis longus and brevis, fibularis tertius
What supplies the dorsal and plantar side of the foot?
- anterior tibial artery does dorsal
- posterior tibial artery does plantar
Anterior tibial artery enters the anterior compartment of the leg proximal to the…
-interosseous membrane between tibia and fibula
The anterior tibial artery courses with the __________ and supplies the anterior compartment of the leg. It continues as the __________ on the dorsal aspect of the foot. This artery then branches into what?
- deep fibular nerve
- dorsalis pedis
- dorsalis pedis branches into the arcuate artery which supplies the toes via digital branches and the deep plantar artery which contributes to a plantar arterial arch on the sole of the foot
The posterior tibial artery arises from the ______ and courses through the posterior leg compartment with the _______.
- popliteal artery
- tibial nerve
Posterior tibial artery gives rise to the ___________ which supplies the posterior compartment of the leg and sends perforating branches into the lateral compartment of the leg to supply what muscles in the posterior leg?
- fibular artery
- fibularis longus and brevis muscles
The posterior tibial artery passes into the foot behind the medial malleolus adjacent to the tendons of _____________ and it then divides into the medial and plantar arteries, which supply the sole of the foot.
- tibialis posterior
- flexor digitorum longus
The intrinsic muscles of the plantar side of the foot are innervated by?
-medial or lateral plantar nerves, both branches of the tibial nerve
Intrinsic muscles of the foot are divided into ___ layers.
4
Layer 1 components
- abductor digiti minimi
- flexor digitorum brevis
- abductor hallucis
Layer 2 components
- lumbricals
- quadratus plantae
Layer 3 components
- flexor digiti minimus brevis
- flexor halluces brevis
- adductor halluces
Layer 4 components
- plantar interossei
- dorsal interossei of foot
Abductor digiti minimi function
-abducts and flexes digit 5
Flexor digitorum brevis function
-flexes lateral 4 digits
Abductor hallucis
-abducts and flexes the great toe
Lumbricals
-flex proximal phalanges, but extends middle and distal phalanges because they insert on the dorsal digital expansions of digits 2-5
Quadratus plantae
-assists flexor digitorum longus in flexing lateral 4 digits
Flexor digiti minimi brevis
-flexes the proximal phalanx of digit 5
Flexor halluces brevis
-flexes the proximal phalanx of hallux
Adductor halluces
-adducts the hallux
Plantar interossei
-adducts digits 3-5 and flexes the metatarsophalangeal joints of digits 3-5
Dorsal interossei of foot
-abducts digits 2-4 and flexes the metatarsophalangeal joints
Where is the tarsal tunnel located?
-medial aspect of foot
Name the structures that pass through the tarsal tunnel (inferior and posterior to medial malleolus)
- Tibialis posterior
- Flexor digitorum longus
- posterior tibial artery
- posterior tibial vein
- tibial nerve
- flexor hallucis longus
