Joint Fractures and Traumatic Luxations

Question 1

describe articular fractures

Answer 1

fractures involving the articular cartilage and subchondral bone

Question 2

describe the diagnostic tools that may be indicated to make an accurate diagnosis and appropriate treatment plan

Answer 2

1. radiographs! when stable, collimated, orthogonal views
2. may augment orthogonal rads with stress views (helpful if suspicious of joint instability, if can open joint spaces may indicate ligament injury), oblique views (to combat superimposition), and contralateral (for comparison) views
3. CT is more sensitive than rads

all may be required!

Question 3

what are the 3 treatment options of articular fractures?

Answer 3

1. fracture repair: ideal if possible
2. salvage options: next best if repair not possible
3. conservative/amputation: avoid if possible!

Question 4

list the fundamental principles of articular fracture repair (4)

Answer 4

must achieve anatomic reduction AND RIGID internal fixation to:

-promote PRIMARY bone healing; don’t want callus formation!
-promote EARLY return to function
-and mitigate development of degenerative joint disease

Question 5

describe methods of articular fracture repair (3)

Answer 5

interfragmentary compression can be helpful to minimize the fracture gap and optimize primary bone healing! achieve by

1. manual compression with reduction forceps (skeletally immature animals, have softer bone so easier to achieve compression this way)
2. screws place in lag fashion
3. pin and tension band wire fixation; converts distractive forces from ligaments pulling on bone into compressive forces and rigid stability

Question 6

describe considerations of articular fractures in juvelines (2)

Answer 6

1. gentle tissue handling is key! minimize disruption of blood supply and minimize further injury to growth plate
2. do NOT span physis with a rigid implant; prevents further growth! cross pins are often sufficient (smooth and as perpendicular as you can so growth plate can still grow around pins

Question 7

what are the 3 salvage options if cannot achieve anatomic reduction and rigid fixation?

Answer 7

1. joint replacement: provides optimal function
2. joint fusion (arthrodesis): with a plate, no mobility in joint but usually good limb function and other joints compensate
3. hip joint: femoral head ostectomy (excision arthroplasty); not as optimal function

Question 8

describe post-traumatic osteoarthritis

Answer 8

1. an inevitable consequence of articular fractures (cartilage injury)

minimize progression by:
1. limiting iatrogenic trauma (minimal invasive)
2. performing surgery early (within 3 days if possible)
3. adhering to fundamental principles of anatomic reduction and rigid fixation
4. promoting early return to function: controlled weight bearing, PROM, PT
5. initiate osteoarthritis management

Question 9

describe the main complications and adverse sequelae associated with articular fractures

Answer 9

like with any fracture repair:
1. infection: can lead to septic arthritis!
2. implant failure/migration
3. delayed, mal, nonunion

for articular fractures specifically:
1. osteoarthritis
2. reduced ROM/joint function

Question 10

describe traumatic joint luxations

Answer 10

1. dislocation of a bone from a joint secondary to trauma
2. describe the position of the distal bone in relation to proximal bone
3. tyically involves joint capsule rupture and disruption of ligament(s)

Question 11

describe joint laxatiy/subluxation

Answer 11

1. used to describe partial dislocation
2. soft tissue injury typically less severe than with complete luxation

Question 12

describe presentation and diagnosis of traumatic luxation

Answer 12

presentation: acute onset +/- history of trauma, typically non weight bearing

diagnosis:
1. ortho exam; use anatomic landmarks! (pelvic triangle)
2. orthogonal radiographs: +/- stressed views for subluxation/instability

Question 13

describe treatment principles of traumatic joint luxations (3)

Answer 13

1. restore normal anatomic relationship
2. provide stability to joint (NOT rigid!)
3. preserve normal joint ROM

Question 14

describe treatment options of traumatic joint luxations

Answer 14

preferred if possible:
1. closed reduction, no sx: attempted if acute (3-5 d)
2. open reduction and stabilization: if chronic (contracture), failed closed reduction or reluxation

salvage options: consider if severe OA, intra-articular fragments, and/or sx complications
1. joint replacement
2. arthrodesis
3. excision arthroplasty

not ideal but may be acceptable: if severe financial constraints and/or complications
1. amputation
2. medical management

Question 15

what does treatment option of traumatic joint luxations depend on? prognosis?

Answer 15

1. the joint involved
2. the chronicity
3. concurrent diseases/injuries
4. owner and patient compliance
5. owner expectations and finances

prognosis is similarly variable, dependent on severity, chronicity, and treatment option

Question 16

describe shoulder luxation, preferred treatment options, salvage options, and post-reduction coaptation

Answer 16

can be in medial, lateral, caudal, or cranial direction; medial is most common, lateral is more likely in large breed dogs

preferred tx options:
1. closed reduction and coaptation: often successful if performed early
2. open reduction and stabilization: prosthetic ligaments, biceps tendon transposition

salvage options:
1. excision arthroplasty (glenoid excision, better in smaller dogs)
2. arthrodesis

post-reduction coaptation (2-4 weeks)
1. medial:
-velpeau sling forces humeral head lateral
-hobbles (immobilizes)
2. lateral:
-spica splint forces humeral head medial
-hobbles: immobilizes

Question 17

describe elbow luxation, preferred treatment options, salvage options, and post-reduction coaptation

Answer 17

direction: most often (>90%) lateral, often with large breed dogs, see typical stance (elbow adducted and antebrachium externally rotated) on slide and orthogonal views are hella important!

preferred:
1. closed reduction and coaptation: often successful if performed early, lower success in cats (higher chance to reluxate, probs just go straight to sx) than dogs
2. open reduction and stabilization: prosthetic ligaments

salvage:
1. athrodesis

post-reduction coaptation: 2-4 weeks
spica splint, maintains elbow in extension

Question 18

describe antebrachiocarpal luxation, preferred treatment options, salvage options, and post-reduction coaptation

Answer 18

direction: dorsal or palmar;
-usually due to major trauma in dogs, both collateral ligaments as well as the palmar support structures if hyperextension
-often due to less severe trauma in cats, can occur due to rupture of the medial collateral ligament alone! often results in palmar luxation

preferred treatment options:
(a note): closed reduction and coaptation is often unsuccessful
1. open reduction and stabilization: prosthetic ligaments can be successful IF injury is isolated to collateral ligaments (more common in cats than dogs)
2. pancarpal arthrodesis: required if palmar support structures are affected (most dogs)

post-op copatation: 2-4 weeks
palmar splint bandage

Question 19

describe sacroiliac luxation, preferred treatment options, salvage options, and post-reduction coaptation

Answer 19

direction: craniodorsal; typically associated with 2 or more pelvic fractures
radiographs: need to see straight! VD pelvis is most helpful, follow medial contour of ilial wing

treatment options:
1. open reduction and stabilization: use a sacroiliac screw (lag or positional)
2. conservative management: strict crate rest (6-8 weeks)

Question 20

when do you recommend surgery for a sacroiliac luxation? how?

Answer 20

when: decision should be made within 5-7d of injury bc over time sx becomes significantly more challenging bc so much muscle around pelvis = lots of contracture

how:
1. >50% displaced or highly unstable
2. >50% pelvic canal narrowing, especially in cats concernec about ability to defecate
3. neuro status: if present, operate
4. pain: severe pain or unwilling to use limb after 3-5 days operate
5. polytrauma: affecting ability to ambulate (case-dependent)

Question 21

describe hip luxation, preferred treatment options, salvage options, and post-reduction coaptation

Answer 21

direction: craniodorsal (75%) or caudoventral (15%)
-caudoventral luxations occur due to forced limb abduciton (splayed); associated with fracture of greater trochanter; femoral head can be displaced in obturator foramen = painful!

diagnosis:
1. thumb test: stick thumb in depression behind greater trochanter, externally rotate greater trochanter and thumb should get pushed out, if not is luxated
2. pelvic triangle

preferred treatment:
1. closed reduction +/- coaptation: successful if perform early, more success if caudoventral than craniodorsal
2. open reduction and stabilization: toggle rod

salvage: both indicated if underlying hip disease
1. total hip replacement: large breed dogs, when owner expects normal hip function, dog is active, sport/working
2. FHO (excisional arthroplasty): financial constraints, companion pets (small breed dogs cope better with this); some large breed dogs can tolerate

post-op coaptation: 4-6!!! weeks
1. ehmer sling: craniodorsal luxation
2. hobbles (prevent splaying): caudoventral luxation

Question 22

describe stifle luxation, preferred treatment options, salvage options, and post-reduction coaptation

Answer 22

deranged stifle: disruption of at least 2 major ligaments (collaterals, cruciates)

complete luxation: hella rare, more likely in cats, requires disruption of all 4 ligaments, vascular integrity of distal limb must be carefully evaluated (often compromised)

preferred treatment options:
1. open reduction and stabilization: prosthetic ligaments, extracapsular suture, temp immobilization with trans-articular ESF

salvage: arthrodesis

Question 23

describe tarsocrural luxation, preferred treatment options, salvage options, and post-reduction coaptation

Answer 23

typically involved disruption of both medial and lateral supporting structures (malleolar fracture, collateral ligament rupture(s), shearing injury, medial side more commonly affected)

preferred treatment:
1. closed reduction and coaptation: often unsuccessful
2. open reduction and stabilization: prosthetic ligaments, malleolar fracture repair, transarticualr ESF (if severe shearing injury)

salvage: arthrodesis

post-op copatation 2-4 weeks:
lateral splint bandage

Question 24

describe digit luxation, preferred treatment options, salvage options, and post-reduction coaptation

Answer 24

relatively common

preferred treatment options:
1. closed reduction and coaptation: often unsuccessful
2. open reduction and stabilization: may be preferred over closed in working dogs, suture repair +/- prosthetic ligament

salvage: arthrodesis

post-reduction coaptation: palmar/plantar splint bandage

Question 25

compare and contrast the common preferred treatments (2) to the salvage treatments (3) for all the joints

Answer 25

preferred:
1. closed reduction: reasonable first line treatment for acute luxations of shoulders, hips, elbows, and digits

2. open reduction and stabilization: reasonable for all joints (if no severe underlying disease)

salvage:
1. joint replacement: reasonable salvage option for hips

2. arthrodesis: very reasonable salvage option for carpus and tarsus
   -shoulders, elbows, and stifles can do okay but will have mechanical lameness
3. excision arthroplasty: very reasonable salvage option for hips, shoulders can do okay