Exam III - Diagnosis and Treatment of diseases & injuries of the Stifle I & II, and of the elbow

Question 1

stifle

Identify findings for CrCL disease:
signalment
history
orthopedic exam

Answer 1

History: For history, you will usually hear “we were jut at the dog park, I didn’t even see what happened”. They could aos have a history of lameness.
* Lameness may be prolonged, intermittent and mild (partial tear). Lameness may be acute and severe (complete tear). Lameness may partially improve then becomes and stays severe (secondary meniscal injury).

Signalment: Could also be a young (skeletally immature) athletic dogs where they have an acute avulsion injury (structure will be softer and weaker at this age)
Early neuter (growth plates stay open longer) or straight legged conformation are potentially put at a higher risk
Dogs with a higher than average tibia plateau angle are at a higher risk.
For small breed dogs, happens when they are older and overweight, its usually an acute complete rupture and may be secondary to MPL*

During the orthopedic exam you may see:
Gait: significant lameness and a positive sit test
Standing: muslce atrophy and medial buttress
stifle manipulation: pain on ROM, crepitus/clicks, and (cranial draw test) instability. Can also do the flexor thrust.

cranial thrust may not always be present with injury

Question 2

stifle

How do you calculate the tibia plateau angle?

Answer 2

you a draw a vertical line between the eminence and middle of weight bearing surface on the distal side, which is the mechanical functional access of the tibia.

then you draw a line that cross the tibia plateau perpendicular to the function axis. The tibia slope itself in the tibia plateau angle.

The average is 25-30 degrees
and excessive is over 35.

Question 3

stifle

Why is it important to know a patient’s TPA before treatment?

Answer 3

If a dog has a TPA of greater than 40 degrees, they are poor candidates for conservative management, ExCap, and TTA.

They are treated best with TPLO

Question 4

stifle

What other soft tissue injury is often associated with CrCL?

Answer 4

a meniscal injury. There will often be damge to the caudal pole of the medial meniscus because it is tagged down on the tibia by a firm ligament.

The lateral meniscus does not get run over becasue it is attached to the femur and “moves freely”

This injury has a 50-90% incidence rate.

Question 5

stifle

True or false: During arthotomy or arthroscopy, you’ll always be able to visualize enough to make a diagnosis.

Answer 5

False, probing increases accuracy by 8 times.

Question 6

stifle

From best to less, the best surgical approach for a CrCL between TPLO, Excap, TTA, and conservative management is:

When it comes to return of comfortable function

Answer 6

TTA>TPLO>ExCap>Conservative

Question 7

stifle

When it comes to unilateral CrCL ruptures, what should we tell the owner?

and prognosis

Answer 7

~50% Contralateral CrCL
rupture within
12-18 months

All surgical techniques
quote 80-90% return to
‘normal’ function

Question 8

stifle

What are some causes of primary malalignment of the extensor mechanis, (i.e the stifle)?

Answer 8

shallow trochlear groove (patella never in right place so groove is never formed)
malpositioning of the tibial tuberosity
distal femoral varus (or valgus)
excessive laxity and fibrosis of soft tissues

Question 9

stifle

Would you expect a large breed dog to have medial or lateral patella luxation?

may be tricky question

Answer 9

medial patella luxation is most common across all breeds but especially in small breeds and if you see lateral patella luxation, it’s usually in large breed dogs

Question 10

stifle

what are the different grades of MPL?

Answer 10

grade 1:
* Subluxates with digital pressure,
but spontaneously reduces
* Rare spontaneous luxation &
lameness
* Normal in cats?

grade 2:
* Luxates manually &
spontaneously
* Can be manually reduced
or spontaneously reduces
* “Spends most of its time in
the groove”
* Intermittent lameness or
“skipping lameness.”

grade 3:
* Patella is luxated, but can
be manually reduced
* May walk crouched with
stifle semi-flexed
* Patella spends more time
“out than in”

grade 4:
* Permanently luxated & cannot be
reduced
* May carry limb or walk crouched
* Severe gait changes (hand-stands)

in grade 4, the patella is almost 90 degree to where it should be

Question 11

stifle

What grade of MPL would you recommend surgery?

Answer 11

2-3, 4 is challenging - may not get ideal function in with best efforts.