Elbow joint replacement

Question 1

what are the primary and secondary indications for elective elbow joint replacement

Answer 1

1. pain relief

2. restoration of stability

Question 2

what do most elective patients suffer from

Answer 2

RA

Question 3

what are the primary functions of the elbow

Answer 3

positioning of the hand in space
allowing the forearm to act as a lever

it may also act as a weight bearing joint for certain people e.g. those who use a walking aid

Question 4

name the 3 articulations of the elbow joint

Answer 4

humeroulnar
humeroradial
proximal radioulnar

Question 5

what part of the joint generally carries most of the load

Answer 5

humeroulnar articulation

Question 6

in anatomical position whats the alignment of the forearm in relation to the upper arm?

Answer 6

10-15 degrees of valgus angulation

with flexion this reduces

Question 7

For activities of daily living how much flexion, pronation and supination should the elbow allow?

Answer 7

30 - 130 flexion

50 of both pronation and supination

Question 8

what provides most stability at the elbow joint - congruity of joint surfaces or soft tissues?

Answer 8

both equally!

Question 9

what ligament is particularly important to elbow stability and why

Answer 9

MCL
because in most activities of daily living the elbow is flexed, and the MCL provides over half of the joint stability in flexion

Question 10

what other joint can affect the loadings on the elbow

Answer 10

shoulder joint

• stiffness at the shoulder increases rotational stresses at the bone-cement interface if the person attempts internal or external rotation
• this is a reason why shoulder replacement may be given priority over the elbow

Question 11

what does the Dee prosthesis consist of

Answer 11

3 cobalt chrome parts

• humeral component
• ulnar component
• axis pin

Question 12

why did the Dee prosthesis not have good long term results

Answer 12

single axis motion is unnatural to the joint&raquo_space; high shear forces at bone-cement interface
also high amount of metal wear from metal-on-metal articulations

Question 13

what can 2nd gen prostheses be divided into

Answer 13

semiconstrained metal-to-polyethylene hinge

unconstrained metal-to-polyethylene resurface types

Question 14

when is semi-constrained type more suitable than unconstrained

Answer 14

when there is some soft tissue insufficiency and loss of bone stock bc it adds some stability

Question 15

how much valgus and varus motion does the tri-axial semiconstrained prosthesis allow?

Answer 15

around 5 degrees varus and 6 degrees valgus laxity

Question 16

name an example of an unconstrained prosthesis and what does it consist of

Answer 16

souter-strathclyde

• humeral component replaced with vitallium
• ulnar component replaced with HDP

Question 17

what is the advantage of radial head resurfacing

Answer 17

load transmission stability offered by the humeroradial artic.

Question 18

name a design that uses radial head resurfacing

Answer 18

pritchard replacement