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Small Animal Medicine and Surgery: Orthopedics: Pediatrics

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Why are fractures and puppies and kittens generally very gratifying to treat?
- Because they heal so rapidly and well
How long does of fracture take to Unite in adults?
- 6 to 8 weeks
How long might one expect a fracture to unite in a five-month-old?
- 3 to 4 weeks
In general when might external coaptation be a successful treatment for Many fractures?
- If the fracture is below the level of the elbow and stifle

-
How much hardware is needed if external or internal surgical fixation is used in a young animal?
- less and a young animal than older
Letter specific problems to worry about in young fractures?
1. Limb shortening, growth deformity and joint dysplasia


2. Osteopenia, impeded growth of immobilized bones, and ligamentous laxity (fortunately this latter is usually transitory)

3. Quadriceps contracture

4. Marked joint stiffening (or excessive joint laxity!)

5. Excessive callus formation
Why may limb shortening, growth deformity and joint dysplasia occur?
resulting from premature closure of a fractured growth plate
Why may osteopenia, impeded growth of the mobilized bones, and ligamentous laxity occur?
due to splinting or casting of limbs in puppies and kittens
Whining marked joint stiffening occur Or excessive joint laxity occur?
resulting from external coaptation
When my quadriceps contracture ocher?
- following distal femoral fracture repair
What is the problem with excessive callus formation?
causing decreased muscle/tendon mobility or joint impingement
If the young animal comes in limping what are two Differentials you should be thinking about?
1. Septic arthritis

2. fracture
what kind of fractures are common in young animals?
- Green stick

- fissures

- folding fractures with minimal displacement
What are key points to keep in mind in order to avoid complications in paediatrics ?
1. Frequent monitoring

2. Aggressive physical rehabilitation

3. early surgical intervention if quadriceps contractor or growth deformities are detected
What should be involved in frequent monitoring?
1. splints should be changed at least weekly;

2. radiographs
How often should radiographs be taken?

Why might you consider taking radiographs several months beyond the point of fracture union?

Why might you radiograph the opposite limb?
- should be taken every two weeks

- radiography should continue for several months beyond the point of fracture union if there is a concern about growth deformity occurring

- Radiographing the opposite normal limb for comparison can be very helpful here
give an example where aggressive physical rehabilitation is important?
Distal femoral fractures
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From what area do long bones only grow longer from?
- Growth plates

=physes: these form the metaphyses and diaphyses
What does articular cartilage form?
- The bone of the epiphyses
What are the different Physeal zones?
- Reserve layer/ germinal layer

- zone of proliferation

- zone of hypertrophy

- zone of calcification
What is the resting her reserve layer?

on what side does bone get laid down?
- The cells that have to be present and active for growth to continue live here

- the cells are busy reproducing

- reserve layer is right up against the epiphysis → so bone gets laid down on the metaphyseal side, effectively pushing the metaphysis away from the epiphysis
If a fracture occurs through growth plate in what zone is the fracture likely to occur through?

Why is the bone so capable of continued growth as a result?
- The zone of hypertrophy

- this leaves the reserve cells clinging to the epiphysis
Which side of the growth plate do you need to be very gentle with if you are repairing a physeal fx?
- the epiphyseal side

- No scooping out hematoma, no scraping the fracture surfaces so thst you can fit things together better
IMAGE normal anatomy
Salter 1

Describe a Salter 1 fracture? what is that also known as
- straight across the physis.

- Also known as an epiphyseal slip fracture
What is the ideal location for this fracture Salter 1 in the growth plate? Why?
- within the zone of hypertrophy or at the junction between the zone of hypertrophy and the zone of calcification

- this is a good thing, because it leaves the germinal cells uninjured and allows new bone formation to continue.
What areas are prone to Salter I fractures?
- Fractures of the distal radius

- capital femoral physis
Salter II
What is a salter 2 fx?

what is the prognosis for growth and function of the bone once it heals?

what area is this fracture common in?
- Across the physis part way and then up the metaphysis on one side

- Similar prognosis (generally good for function and continued growth) to Salter 1 fractures

- Most fractures of the distal femoral physis
What is a Salter III fracture?
- Goes from the articular surface up through the epiphysis and then across the physis
What is the main concern about a Salter III fracture? What is the consequence of this?
- fracture is articular

- so the chance for osteoarthritis is high unless you achieve a nice, perfect, rigid reduction and fixation
What a common areas for Salter III fractures?
- Distal tibia's
Salter IV
What is a salter IV fx?
- Goes from the articular surface to the metaphysis and thus crosses perpendicular to the growth plate
Do Salter 4 fx cause growth plate closure?

What is a concern about such fractures?

What bones most commonly have this fracture?
- No

- their articular

- distal humerus, usually on the lateral side of the condyle
Salter 5 fx
What is a Salter 5 fx?

does this fracture generally produced displacement? Is it visible on radiographs?

When you usually conclude that there is such a fractured present?
- is a crushing injury to the physis

- doesn't usually produce displacement and indeed may not be visible on initial radiographs

- Only when bone stops growing prematurely and deformities result
What areas are bones are most common to have a Salter five fx?
- Canine distal ulnas
Why a canine distal ulna's common sites for Salter 5 fx?

compare this to a cat ulna? What kind of fracture and a more prone to?
- as their conical shape make them prone to getting smushed

- Cat ulnas have straight physes and thus are prone to Salter 1 fractures here instead
Salter 6 fx:

What is a Salter 6 fx?

What is the consequence?
- A crushing or bridging injury involving only part of a physis

- The uninjured part keeps growing, and a deformity results
What determines whether or not a growth plate will close prematurely after his been fractured?
1. The nature of the fracture

2. method used to repair it
Which Salter Harris fracture type is less likely to produce premature closure?

Give an example of the location where there might be some crushing component to the example?
- Salter-Harris Type 1 fractures, where the epiphysis merely "slips" away from the metaphysis along the line of the growth plate

- are less likely to produce premature closure than crushing injuries, but in reality even Type 1 fractures in certain locations (like the capital femoral physis) seem to have some crushing component to them
In what circumstances are physeal fractures less likely to close Prematurely?
1. if they are held in place with external coaptation (ideal in theory but difficult to accomplish in many locations)

2. with pins placed parallel to the plane of growth
What effect will cross spinning have on growth plates?
allows for some growth but will ultimately produce compression of the physis.
what are other repair methods that reliably produce premature closure of the growth plate?
- spanning the fracture site with plates, screws, or tension band fixation
what determine the nature of the problem or deformity resulting in premature closure of the growth plate?
- If it (GP) is a single bone system such as the femur or humerous or two bones system
Describe one bone system and gross deformity? What is usually a consequence?
- What typically happens with premature physeal closure in single bones is simple limb shortening.
Is limb shortening a concern?

What may or may not happen in some patients to make up for some the femoral deficits?
- This is often not as big a problem as you might think, since up to 20 % shortening of a femur is tolerated before a visible gait deficit will be noted


- If your patient is lucky (or maybe enterprising) there will be compensatory overgrowth of the tibia that will help make up for some of the femoral deficit
What might premature closure of the distal femoral physis in the dog up to five months cause?

what should be done in such cases?
- may cause crippling shortening of the limb

- so in these cases measures (like distraction osteogenesis) should be taken to lengthen the limb during the animal's growth phase.
When might you get a bending bone even in a one bone system?
got asymmetric closure of a growth plate
Describe the two bone system And premature physeal closure?
much more of a pain in the butt
What is the concern if one bone in the 2 bone system grows faster than another?
1. angular and rotational deformities

2. has the potential to trash joints involved with the two disparate bones
In premature closure in 2 bone systems, what actually causes the persistent lameness seen?
Joint incongruity
With the radius and ulna, which joint tends to take the biggest hit in asymmetric growth?
- The elbow
What are most common Locations of growth deformities of the dog? Why?
- Radius and ulna

- the radius has two growth plates contributing to the length of the diaphysis (so if one is injured, the other can take up some of the slack), but the ulna only has one growth plate contributing to diaphyseal length
What is the concern about the one growth plate in the Ulna in the dog?
- cone-shaped nature of the epiphysis makes this growth plate particularly prone to crushing injury, with disastrous effects
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What is the only effective treatment for premature physeal closure and joint problems resulting from them?
Surgery
What are different categories of surgical treatments for growth deformities?
1. Preemptive procedures

2. Distraction osteogenesis
What are Preemptive procedures?

When are they usually done?

what goal is hopefully achieved?
- relatively simple operations done early in the course of the disease (think 3-5½ months of age)

- hopes that continued growth after the operation will prevent joint incongruity and allow for self-correction of any deformity present
Give an example of the most common preemptive procedure and dogs?
ulnar ostectomy
What is an ulnar ostectomy?
removal of a segment of ulna along with its periosteum, sometimes with some fat placed in the gap to slow healing

—to prevent the tethering effect of an ulna with distal physeal closure on the growth of the radius.
what is distraction osteogenesis?

what kind of fixators are often used in this process?
- This involves making a cut in the cortex (at least) of the shortened bone and slowly moving the two resultant fragments away from each other while bone forms in between them

- Circular external fixator
What can distraction osteogenesis result in?
- "grow" a bone longer

- can also be used to correct angular and rotational deformities
When can a distraction osteogenesis be done? 2
- either during the growth phase or after the animal has reached skeletal maturity
why are we concerned about the presence of deformities?
Because of the effects on the elbow
What are examples of breeds in which we breed them specifically for the forelimb deformities?
- Shih tzus

- basset hounds
What are the main concerns regarding the elbow, when it comes to the radius and ulna growing at different rates?
- subluxation of the elbow
What can subluxation of the elbow lead to?
- Persistent joint pain and osteoarthritis
What kind of procedure may help to deal with elbow incongruity?
dynamic proximal ulnar osteotomy

- either lengthening the shorter bone or shortening the longer bone
described definitive repair of a deformity?
performed after the rapid growth phase, when simpler preemptive procedures are unlikely to be effective
How may a definitive repair be accomplished?
- distraction osteogenesis

- with a bewildering variety of corrective osteotomies held in place with either bone plates or external fixators.
When does radius curvuus occur?
Premature closure of the distal ulnar physis
How much of the growth in length of the entire ulna does the distal ulnar physis account for?

what happens if the distal ulna physis stops growing is?
- 85% , also growth from the elbow distally

- so does the ulna, which serves as a "string" to the "bow" of the growing radius
Describe how radius curvuus occurs?
- distal ulna physis stops growing → ulna stops growing → Serves as a string to the bow of the growing radius

- growing radius pushes the humerus away from the ulna in the elbow joint

- radius crosses over the ulna in the forarm, and as it grows it causes external rotation of the foot as well as valgus angulation of the distal forelimb.

- the limb is shorter than it ought to be.
What is humeroulnar subluxation?

wise it the biggest problem in radius curvuus?
- growing radius pushes the humerus away from the ulna in elbow joint

- causes osteoarthritis in the elbow
What are treatments for radius curvuus?
1. Segmental ulnar ostectomy

2. Dynamic proximal ulnar osteotomy

3. Corrective radial osteotomy
Describe segmental ulnar ostectomy?
This is often all you need if the dog is less than 6 months of age
Describe dynamic proximal ulnarOsteotomy?

Does it correct the pain? What may prevent?
Won't correct the deformity

but it will get rid of the elbow pain and (if done early enough)

may prevent elbow osteoarthritis.
Describe the corrective radial osteotomy?

what does it need to be combined with? why?
- This alleviates the deformity

- it needs to be combined with something like dynamic proximal ulnar osteotomy to address the elbow subluxation
What problems does premature closure of the distal or proximal radial physis produce? you get angular deformities?
- usually produces minimal or no angular deformity of the limb (if you get one, it's usually a varus deformity of the carpus)

- A problem is elbow joint→ produces humeroradial subluxation
What is the treatment for distorted proximal radial physis premature closure?
1. Distraction osteogenesis of the radius → especially if the animal is quite young when premature radial physial closure occurs

2. radial osteotomy

3. ulnar ostectomy → make the ulna shorter
when might you do radial osteotomy?
- : In an older animal you may be able to just cut the proximal radius, distract it, and fix it in position
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Describe asymmetric closure of the distal radial physis?
- More common than you think

- produces a simple angulation of the carpus without rotational malalignment

- usually elbow is spared
How is an asymmetric closure of the distal radial phsysis treated?
- Corrective radio osteotomy

- can be done either as a one step procedure or distraction osteogenesis
What is radioulnar synostosis?
- doesn't involve premature closure of a physis, but the results can be even more devastating to the elbow joint

- when the radius and ulna weld together after a fracture of both → A good reason to follow radius/ulna fx in young animals very carefully long after union has been achieved
Why does radioulnar synostosis occur?

what is the end result?
- The proximal radial physis continues to produce radial growth above the level of the synostosis but since the ulna cannot grow above the synostosis it stays where it is

- As a result, the radius pushes the humerus away from the ulna, producing an amazing degree of humeroulnar subluxation
What is the tx for radioulnar synostosis?
: ulnar osteotomy above the level of the synostosis
What is Pes Varus?

What does this seem to be due to?

What is the end result? Is there any rotational alignment?
-Most common dachshunds, can occur sporadically and other dogs

either:

1. an asymmetric closure of the distal tibial physis

2. or a disparity on growth between the distal tibial and fibular physes

end result is varus angulation of the foot with no rotational malalignment
What is the treatment for Pes varus?
classic fix for this is an opening wedge osteotomy of the tibia held in place with a hybrid external fixator.
What is Delayed closure of tibial tuberosity physis?

in what dogs doesn't seem to be most common in?
- Can cause significantly lameness and deformity

- the proximal tibial physis fails to mineralize by its usual time of 9-11 months of age, or it does so asymmetrically


- This seems to be most common in dogs spayed/neutered before 5 months of age
What is the end result from the lack of mineralization of the tibial physics?

what kind of appearance does the limb have?
- can be a progressive caudomedial sloping of the tibial plateau → resulting in excessive strain on (and eventual rupture of) the cranial cruciate ligament as well as medial bowing of the tibia to produce a bowlegged appearance of the limb
What is the treatment for delayed closure of the tibial tuberosity?

what is the advantage or disadvantage of either of these procedures?
1. Screw closure of tibial tuberosity growth plate → this won't correct excessive sloping that is already present, but it will prevent more sloping from occurring.


2. ToTibial plateau leveling osteotomy (TPLO) is the way to correct excessive tibial plateau slope.
When does delayed closure of capital femoral epiphysis occur?
- seen in cats

- Neutering of male cats before sexual maturity delays the closure of their capital femoral growth plates
What cats are Delayed closure of capital femoral epiphyses Commonly seen in?

Does it involve one or both sides?
- neutered male cats between 1 and 2 years of age, and the problem is frequently bilateral
What happens to the femoral head and neck as the fractures become more chronic?
- take on the lytic appearance often seen with Legg-Perthes disease (we'll get to that in another lecture).
How do cats commonly present?
- painful hips

- cow hocked waddling gait
What is the treatment?
femoral head exision
What is puppy carpal flexural deformity? What is the signalment usually?
- primarily in large breed dogs during their rapid growth phase

- may affect one or several pups in a litter,

- generally occurring when they are between 8 and 12 weeks of age
How do puppies with Carpal Flexural Deformity present?

is it painful?
- buckle forward at their carpi

- sometimes to the point that they are almost walking on the medial aspect of their feet

- They do not seem to be painful
Why does this puppy carpal flexural deformity occur?
- thought to be due to slow growth of the flexor carpi ulnaris tendon relative to the bones and extensor tendons.
What is the treatment for puppy carpal flexural deformity? What is the prognosis?
- reliably self-corrects over a period of a couple of weeks to a couple of months.

- Treatment: Moderate physical activity on good footing with lots of friction. There is no real need for splinting.

- Example she given class, dog had a splint for less than 18 hours and showed significant improvement
What is puppy carpal hyperextension?

What is the signalment?

What is the treatment?

What is the prognosis?

Is there pain?
- is usually seen in large breed dogs, usually a little later in life (4-5 months) than the flexural deformity is

- Sometimes it is accompanied by tarsal hyperflexion

- This also usually gets better with time, controlled diet and good footing, although it does not always completely go away:

- some laxity may remain for life. It does not seem to be associated with pain
What is swimmer puppy to syndrome?
- Affected puppies slither around on their bellies with their limbs—at least the hind ones—splayed out to their sides as if they are trying to be particularly inefficient lizards

- They usually have flattened chests as well.
What is the signalment for puppy swimmer syndrome?
- frequently affects several pups in a litter,

- usually the tub-o-lard individuals

- It may be a bit more common in small breed dogs
What is the treatment for swimmer puppy syndrome?
1. carefully monitor weight and slim porky individuals down so there's a reasonable amount of weight for those limbs to bear.

2. Make sure footing is good (like lambskin rather than newspaper).

3. Tape hobbles can be applied to the limbs to prevent splaying

4. physical therapy should be instituted to build up adductor muscles

5. One method is to build a little chute with walls just a little wider than the puppy, and have him walk down it several times a day
What is the prognosis for swimmer puppy syndrome?
This condition usually self corrects if proper measures are taken
What is ectrodactyly?
- to missing bones in a limb

- its most common manifestation is as a split-foot syndrome

- It's usually unilatera

- cause unknown → there's a hereditary basis for most cases in people, but it can also be induced by administration of certain drugs (including nonsteroidal antiinflammatories) during pregnancy in rats.
What deformities are seen commonly with ecrodactyly?
- the radius or ulna, with corresponding elbow incongruities

- Frequently, carpal bones are missing
What case of poorer prognosis?
animals with radius and ulna affected have a poorer prognosis than those with just the split foot and carpu
you have your puppies with ectrodactyly commonly present?
start out weightbearing on the odd limb but have a slowly progressive lameness as joint incongruities and carpal strain develop
How is ectrodactyly tx?
- depends upon the degree and level of the deformity

- And Many animals can be helped with creative partial or pancarpal arthrodesis combined with soft tissue repairs to unite the "feet."
Describe Club foot and forelimb flexor contracture?

Where do they bear wieght as a result?
- individuals have a 90 degree medial deviation and 90 degree external rotation of the hind foot, so that when they walk they bear weight on what turns out to be the bottom of their talus
What age group and animal does this occur CFFFC?
- kitten problem
What is seen on rads with CFFFC?
- luxations (or at least extreme laxities of) the talocentral and calcaneoquartal joints with corresponding resultant contractures of tendons and ligaments so that the feet are held in the abnormal position.

- Occasionally one or both forelimbs is flexed at the carpus
How is CFFFC tx?
- usually correct given time and physical therapy

- Have owners massage the limbs into position several times a day

- splinting for contracted forelimbs may be needed ( sometimes hindlimb) in extension

- theoccasional older kitten with club foot may need to have the contracted tendons cut so that the foot can be returned to a normal position.


occasional older kitten with club foot may need to have the contracted tendons cut so that the foot can be returned to a normal position.
What is a tx method Dr. Linn finds useful?
the splint on for about 5 days and then off for 2-3 before repeating the cycle