HUMERUS: 51

Question 1

main nerves of the humerus and their location

Answer 1

MEDIAL: CAUD TO CRAN: caudal cutaneous antebrachial, ulnar, median, muscolocutaneous

LATERAL: radial nerve (most vulnerable in the distal portion of the humerus where it passes cranio lateral.

Question 2

difference in the distal humerus between cat and dog

Answer 2

cat does not have a supratrochlear foramen but have a supracondylar foramen (proximal to medial epicondyle), through wich passes median nerve and brachial artery

Question 3

proximal humerus: time to phiseal closure and most common S-H type fractures

Answer 3

7,5-12 M DOG
19-26 M CAT

S-H type 1/2 most common

Question 4

how are fractures entering the supratrochlear foramen classified?

Answer 4

supracondylar fractures

fractures of the distal part of the diaphysis do not communicate with the supratrochlear foramen!

Question 5

how to place a cerclage on the humeral shaft and what should be kept in mind?

Answer 5

diaphysis is thinner in the middle and bigger at the ends, so cerclage will tend to slide distally when placed proximally and viceversa.

Question 6

optimal pin diameter for intramedullary pin insertion in the humerus

Answer 6

36-45% of craniocaudal medullary canal measured at distal 80% of the humeral length

Question 7

optimal distal location for intramedullary pin

Answer 7

should be directed in to the medial epicondyle medullary canal.

in cats usually there isn’t enough space so could be directed in the area proximal to the supratrochlear foramen (only if there aren’t fractures of the distal humerus)

Question 8

where to pay attention in pin insertion in the supracondylar region

Answer 8

DOG: radial nerve laterally

CAT: median nerve and brachial artery on the medially placed supracondylar foramen

Question 9

more common site to fracture in the distal humeral condyle and type of fracutures

Answer 9

lateral side

usually are S-H 3/4

Question 10

is it necessary to remove the implants to guarantee a homogeneous bone growth in the distal phisis?

Answer 10

it doesn’t seem necessary because even if the implant crosses the growth plate there isn’t a shortened humerus

Question 11

possible additional implants other than transcondylar lag screw

Answer 11

bone plate, single screw, antirotational pin

Question 12

sequence of operation when appiying a bilateral plate for T-Y intracondylar fractures

Answer 12

1) medial part of the humerus stabilizet to he diaphysis
2) reposition dog in lateral recumbency and stabilize lateral part of the humerus with a lag screw
3) place the lateral plate

most common complication occurred by placing the medial aspect of the condyle in a varus position

Question 13

phisiologic time to humeral condyle centers of ossifications closure

Answer 13

8-12 weeks

Question 14

percentage of correlated FCP in dogs with HIF/IOHC

Answer 14

23,5/25%