LA 13: Simple Eq Fractures

Question 1

Common Fx

Answer 1

Metacarpal/metatarsal II and IV fx - splint bone fx

Distal phalanx (P3) fractures

Question 2

Splint Fx - Facts

Answer 2

Splint bones = head, body, button
FL>HL
2 Mechanisms - internal, external

Question 3

Internal Splint Fx

Answer 3

“Pressure” DT concurrent suspensory desmitis
–splint bones aren’t very WB but intimately related to suspensory
Possible prox sesamoid damage

Question 4

External Splint Fx

Answer 4

Skin/SQ IFX
Sequestration
Tendon, suspensory damage

Question 5

Dx Splint Fx

Answer 5

Palp, nerve blocks, RADS

Suspensory ligament US

Question 6

Tx Splint Fx

Answer 6

If distal 1/3 to 50% then can surgically remove distal fragment
If proximal 1/3 req internal fixation

Question 7

Splint Fx: Proximal Fx req Stabilization

Answer 7

Absence of IFX - just need plates or screws to stabilize IFX
If have an IFX, need to wait and treat the IFX first

Question 8

Why don’t screws need to engage both cortices in a splint fx?

Answer 8

For most equine long bone fx, DO want to engage both cortices
Splint bone fx provides some support but not a major WB bone –> unicortical provides enough stability

Question 9

Splint Fx: callus formation

Answer 9

Reasonable to give horse a chance to heal on it’s own

• -need to warn O that callus formation can cause lameness that req surgery later on
• -ex: can have a fracture that doesn’t start causing lameness until the callus starts to impinge on the suspensory

Question 10

P3 Fx Dx

Answer 10

Hoof testers
Nerve blocks
RADS

Question 11

P3 Fx Healing - foals vs adults

Answer 11

Foals will heal and look radiographically normal

Adults - coffin bones heal with fibrous union, never appear radiographically normal

Question 12

EXAMwhich P3 fractures are articular?

Answer 12

III - sagittal 
II - articular wing fracture
IV - extensor process fx 
V (maybe) - comminuted 
VII *foals*

Question 13

P3 fx: I

Answer 13

Non-articular wing fx

Question 14

P3 fx: II

Answer 14

Articular wing fx

Question 15

P3 Fx: III

Answer 15

sagittal fx - articular. Fixation improves progressions

Question 16

P3 fx: IV

Answer 16

Extensor process fx
Causes lameness but not severe lameness
Can cause major coffin jt OA

Question 17

P3 fx V

Answer 17

Comminuted fx

Maybe articular

Question 18

P3 Fx VI

Answer 18

Solar margin fx
Not articular
Caused by seedy toe, hx of laminitis
Prognosis for healing good but usually assoc with underlying pathology - complicates things

Question 19

P3 fx 7

Answer 19

Foals
Incidental
Can be articular
Don’t usually see lameness

Question 20

P3 Fx Tx - Non-articular

Answer 20

Rest
Shoeing
Neurectomy
Good prog if not complicated by other factors

Question 21

P3 Fx Tx - extensor process (IV)

Answer 21

Bigger they are, prog goes down
Small-medium fragment can be removed arthroscopically as long as don’t have preexisting coffin jt OA
Fixation rarely needed
Good prognosis

Question 22

P3 Fx Tx - other articular fx

Answer 22

Fixation (screw)
Shoeing
Neurectomy (maybe)
Fair to poor prognosis

Question 23

Common Racehorse Fx

Answer 23

Metacarpal/Metatarsal Fx 
--Stress Fx 'Saucer fx' 
--Distal MC3/MT3 'Condylar fx' 
Osteochondral fx 
--carpal 
--prox phalanx P1 
Prox sesamoid bone (PSB) fx

Question 24

Metacarpal Stress Fx

Answer 24

Bucked shin complex - shin splints 
Saucer fx 
Fatigue failure 
--inappropriate training methods 
--microfx

Question 25

Early Phases MC Stress Fx

Answer 25

Sensitive palp, heat, swelling, lame RADS - no fx, sub-periosteal callus, endosteal thickening Mostly front limb

Question 26

Dorsal MC3 Fx

Answer 26

Sensitive to palpation, lame | RADS: dorsolateral cortical fx, endosteal thickening

Question 27

Tx Metacarpal Stress Fx

Answer 27

Drilling 5-7 holes around the fx to increase blood supply, osteoblasts, encourage healing, MSC/open bone marrow NOT A LAG SCREW - just a placement screw --will undergo some bending --More effective than osteosticks Unicortical Recruit additional healing factor Not all need to be repaired sx - if very prox or very distal, generally heal well on their own If in the middle, don't heal well - best to do sx

Question 28

Distal MC3/MT3

Answer 28

Condylar fx CS - lame by the time off track work/race, effusion, very sore to flexion Dx - beware of medial fx - can spiral up cannon bone Lateral condylar fx RARELY spiral Medial condylar WILL spiral

Question 29

Distal MC3/MT3 Fx - Repair

Answer 29

Don't have to repair if $$$ is an issue Displaced = more sore than non-displaced --non-displaced can progress to displaced quickly Alignment with jt most important!!! - arthroscopy Be as close to jt surface as possible Most done under GA but can done standing w/ good sedation and nerve blocks

Question 30

Osteochondral Fx

Answer 30

IA fx - -recurrent synovitis - -osteoarthritis - -shortened athletic career

Question 31

Carpal Osteochondral Fragments

Answer 31

``` Knee chips Etiology: trauma = hyperextension of carpus --distal radiocarpal bone --distal intermediate carpal bone --prox third carpal bone ```

Question 32

Carpal Osteochondral Fragments CS

Answer 32

``` Effusion/lameness after calling out --typically subside within 24-48 hrs --both recur with exercise RADS --4-6 views, both carpi --> lat, flex lateral, D-P, DMPLO, DLPMO, skyline of C3 (flexed separates inner carpal and radiocarpal) ```

Question 33

Carpal Osteochondral Fragments Tx

Answer 33

Arthroscopic sx Fragment removal Debridement

Question 34

Carpal Osteochondral Fragments Prognosis

Answer 34

``` If acute (no OA), and less than 30% cartilage loss, then good for race performance Prog also depends on how quickly address and whether there's pre-existing dz ```

Question 35

Slab Fx

Answer 35

usually involve middle carpal and CMC

Question 36

Chip Fx

Answer 36

Just corners off the cuboidal bones

Question 37

Dorsal, proximal P1 fx

Answer 37

Hyperextension fx RF medial eminence P1 --bilat RADS Lameness, tx, prog as for carpal OC fragments

Question 38

Proximal Sesamoid Bone Fx

Answer 38

6 basic types - -prog decreases as fx becomes more distal (or axial) - -Assess concurrent suspensory desmitis

Question 39

PSB CS

Answer 39

Jt effusion Heat on palp Lameness

Question 40

PSB Tx

Answer 40

Arthroscopic removal Repair: lag screw fixation > circumferential wiring Nothing: retire Prog varies by location --> worse prox to distal

Question 41

Which PSB fx have a good prog?

Answer 41

Apical | Abaxial

Question 42

Which PSB have a poor prog?

Answer 42

Axial Comminuted Esp poor prog if combined with condylar fx

Question 43

Medial and lateral (biaxial) PSB fx

Answer 43

Biaxial fx lead to loss of suspensory apparatus