Lecture 1: Small Animal Carpus and Forepaw Flashcards
What bones make up the carpus
Proximal carpal bones: ulnar, intermedioradial, accessory
Distal carpal bones: 1-4
What are the 3 sections of metacarpal bones from proximal to distal
Base, body, head
The 4th and 5th metacarpal bones articulate with which carpal bone
4th carpal bone
What are the 3 phalanges from proximal to distal
Proximal phalanges, middle phalanges, and distal phalanges
How many phalanges does the dewclaw have
2
What is the purpose of sesamoid bones
Provide a smooth surface for fascia and act as levers/anchors and redistribute forces
what bones are indicated by red box
Carpal bones
what bones are indicated by the red box
Metacarpal bones
What bones are indicated below the red line
Phalanges
Case example: 8 month old, NM lab had box dropped on foot, immediately non-weight bearing lame. The following X-ray was took. What is causing lameness
Fractures to metacarpals 2-5
What are the primary weight bearing metacarpals
3rd and 4th
What are the secondary weight bearing metacarpals
2nd and 5th
When assessing the prior case with fractures to metacarpals 2-5, what digits are most important to stabilize and why
3rd and 4th as they are the primary weight bearing metacarpals
What can we do to treat the metacarpal fractures
Variety of options: pin, plate +/-splint
What would be the best treatment option for fractures to metacarpals 2 and 5 and why
Can just splint as they are not weight bearing toes
What two carpal ligaments are important for proper rotation of carpus
Medial and lateral collateral ligaments
what carpal ligament is indicated by the arrow
Medial collateral ligament
what carpal ligaments are indicated by arrows (red vs purple dot to distinguish sides)
Red: medial collateral ligament
Purple: lateral collateral ligament
What structure prevents hyperextension of carpus and keeps paw in state of flexion
Palmar carpal fibrocartilage
what is indicated by the blue arrow
Palmar carpal fibrocartilage
What is indicated by blue arrow
Palmar carpal fibrocartilage
Case example: 4yr, NM golden retriever jumped off 15ft sea well and acutely lame on right front. Right carpus is painful on flexion/extension and hyperextension of right carpus. X-ray shows the following. What could be the problem
Damage to carpometacaral joint, subluxation
What are the three carpal joints
- Antebraciocarpal (radial)
- Intermediate (middle) carpal
- Carpometacarpal
Which carpal joint permits majority of the flexion and extension of carpus
Antebrachiocarpal joints
What two carpal joints lack mobility
Intermediate (middle)
Carpometacarpal
identify the arrows most proximal to distal
- Antebrachiocarpal joint
- Intermediate (middle) carpal joint
- Carpometacarpal joint
How can you treat a subluxated Carpometacarpal joint
Can pin joint in place as it does not naturally have much mobility
Case example: 3 month old, Great Dane, progressive forelimb lameness. The following picture represents the position of Buster’s forelimbs. What could be wrong
Carpal joints are hyperflexing—> carpal laxity syndrome
In what dogs is carpal laxity syndrome most common
Young growing dogs who have either over or under supplemented diets, poor footing and improper exercise in growing puppies
During carpal laxity syndrome there is weakness and irregular tension between what muscle groups
Extensor and flexor muscle groups
What is the treatment of carpal laxity syndrome
Nutritional food, appropriate exercise, PT, generally resolves over time
Identify 1-5 flexors of carpus
- Superficial digital flexor
- Flexor carpi ulnaris
- Flexor carpi radialis
- Deep digital flexor
- Flexor retinaculum
What nerves innervate the carpal flexors
Median and ulnar nerves
identify the following extensors of carpus 1-3 and 6-7
- Extensor carpi radialis
- Common digital extensor
- Lateral digital extensor
- Abductor pollicus Longos
- Extensor retinaculum
What nerves innervate the extensors of carpus
Radial nerve
What nerves must be blocked for declawing procedure
Radial, median and dorsal cutaneous branch of ulnar nerve
What is the correct site of declawing
Removal of third phalanx
What is polydactyly
Elongated 1st digit, additional digits on medial side of paw
What is the most important food pad for weight bearing
Metacarpal pad
What layer of skin is burned off and what kind of burn
Epidermis is burned off, dermis still present—> partial thickness burn
What is the angular limb deformity seen in this photo
Carpal valgus
what angular limb deformity is seen in this photo
Carpal varus
what percent of radial and ulnar growth comes from the following growth plates
Humeroradial plate: 40% of radial growth
Radiocarpal growth plate: 60% of radial growth
Olecranon growth plate only makes olecranon longer
Ulnar carpal growth plate: 85% of ulnar growth
What happens to growth plates that can result in carpal valgus
Premature distal ulnar physeal closure therefore radial growth is unabated and results in angular changes
What artery is a commonly used for blood pressure
Median artery
what artery is indicated by #3
Median artery
