SA: Muscle, Tendon, and Ligament Injuries

Question 1

What is the healing capacity of vascular tendons?

Answer 1

Triceps, achilles
Good prognosis
Have paratenon (loose connective tissue with blood vessels)

Question 2

What is the healing capacity of avascular tendons?

Answer 2

Digital flexors, biceps
Poor prognosis
Vessels penetrate tendon sheath (hypovascular)

Question 3

Define: Strain

Answer 3

Tendon injury

Question 4

Define: Sprain

Answer 4

Ligament injury

Question 5

Define: Tendon

Answer 5

Muscle-tendon units activate joint motion by contraction
Variably vascular with variable but significant healing capacity

Question 6

Define: Ligament

Answer 6

Support and stabilize joints
Incapable of contracting, tolerate minimal elongation
Relatively avascular = less healing capacities

Question 7

What are the general concepts of muscle and tendon healing?

Answer 7

Tensile forces create gap
Gap healing results in scar tissue
Scar tissue = poor function

Question 8

What are the steps of vascular tendon healing?

Answer 8

Tendon and paratenon (blood supply) laceration
Collagen synthesis within days
Collagen fibers realign in 3-4 weeks
80% normal in 1 year

Question 9

What are the steps of avascular tendon healing?

Answer 9

Tendon and sheath (avascular) laceration
Tendons distract in sheath = gap
Failure to do surgery = nonunion of tendon ends

Question 10

First Degree MT Injury

Answer 10

Hemorrhage but intact fibers (contusion-bruise)

Question 11

Second Degree MT Injury

Answer 11

Hemorrhage and partial fiber disruption (variable elongation)

Question 12

Third Degree MT Injury

Answer 12

Complete rupture of avulsion of attachments

Question 13

Clinical Signs: First Degree MT Injury

Answer 13

Acute pain, inflammation, swelling
Should resolve over 7-14 days (improve without you)

Question 14

Clinical Signs: Second Degree MT Injury

Answer 14

Acute pain, inflammation, swelling
Doesn’t resolve or recurs

Question 15

Clinical Signs: Third Degree MT Injury

Answer 15

Complete dysfunction with strain or joint instability with sprain (luxation)

Question 16

How are ligament injuries diagnosed?

Answer 16

Visible instability/injury/stance abnormalities
Clinical progression (1 v 2 v 3 degree)
Palpation (pain, swelling)
Ultrasound/MRI
Stress radiographs

Question 17

What are the 3 locations that MT injuries can occur?

Answer 17

Origin and insertion (avulsion)
Muscle belly
Tendon

Question 18

Where do MT injuries most commonly occur?

Answer 18

Musculotendinous junction

Question 19

Answer 19

MT injury at superglenoid tubercle (where biceps tendon attaches)

Question 20

How are low-grade MT injuries diagnosed?

Answer 20

Palpate musculotendinous junction while ‘stretching’ muscles individually
Passive flexibility = opposite of function to elastic end feel

Question 21

Why does scar tissue form?

Answer 21

Proliferation of fibrous tissue
Endomysium intact = fiber regeneration
Endomysium damaged = scar tissue
The less vascular supply available, the more scar tissue will form

Question 22

What are the surgical goals of MT repair?

Answer 22

Minimal gap formation: anatomic apposition and maintain that position
Preserve blood supply: minimal trauma/implants

Question 23

How can we preserve blood supply with surgical MT repair?

Answer 23

Atraumatic tissue handling
Mobilization of healthy tendon ends
Skin incision not over injury
Close peratenon if feasible

Question 24

What is important about gap length in MT repair?

Answer 24

Gaps > 3mm impairs healing

Question 25

What is the suture pattern of choice for MT repair?

Answer 25

3 loop pulley - *preferred for larger tendons* Baseball/locking loop - *flat tendons*

Question 26

How long should a patient be immobilized after tendon repair? What is the best solution to this?

Answer 26

6 weeks *Tendon heals better with some ROM* Ideal solution: gradually increase tension across tendon repair with walking bar cast combined with early PT

Question 27

How do we repair SDF/DDF injuries?

Answer 27

Make sure wound is clean (wet-dry bandages if needed) Repair each tendon separately!! *DDF/SDF most important - digit 3 and 4* 3 loop pulley if possible or small tendons with locking loop

Question 28

What is the post-operative care for SDF/DDF tendon repair?

Answer 28

Walking bar for 6 weeks followed by soft padded for 2 weeks thereafter Rehab in walking cast - carpal flexion bandage, orthosis

Question 29

What makes up the common calcaneal tendon?

Answer 29

Biceps femoris tendon Gracillis tendon Semitendinosus tendon Gastrocnemius SDFT

Question 30

What are the 2 types of achilles tendinopathies?

Answer 30

Acute, traumatic injury = true laceration (treat like other tendon laceration) Chronic, degenerative injury = hunting dogs, frequently bilateral (apposition of healthy tendon difficult)

Question 31

What stance is indicative of achilles tendinopathy?

Answer 31

Plantigrade stance Flat paw w stifle in extension = complete rupture of ALL components of the common calcaneal tendon Crab-claw like stance = SDF is intact

Question 32

Answer 32

SDF is intact

Question 33

Answer 33

Complete rupture of all components of the common calcaneal tendon

Question 34

What are the general guidelines for traumatic achilles tendinopathy repair?

Answer 34

Repair each tendon individually if possible 3 loop pulley pattern, prolene suture Hock maintained in extension post-op