Orthopedic Infections

Lameness - progressive to NWB

Swelling

Heat

Fever

What are clinical signs of orthopedic infections?

Synovial

Epiphyseal

Physeal

What are three types of orthopedic infections in foals?

Only synovial membrane/fluid is affected

Larger joints like tarsocrural

What is affected in synovial orthopedic infections of foals under 1 week old?

Synovial and subchondral bone affected

Multiple joints affected

Failure of passive transfer

What is affected in epiphyseal orthopedic infections of foals over 1 week old?

Infection of periphery of long bone - can extend to joint

Previous dz history

What is affected in Physeal orthopedic infections of foals?

Joint effusion

No boney abnormality on rads

How can you differentiate synovial orthopedic infections from the others?

Subchondral bone lysis on rads

Joint effusion

How can you differentiate Epiphyseal orthopedic infections from the others?

No joint effusion

Bony lysis,

Widening of growth plates

How can you differentiate Physeal orthopedic infections from the others?

Nothing this is a normal neonatal foal radiograph

What is the problem w/ this radiograph?

Epiphyseal

Identify the type of infection?

Physeal

Identify the type of infection?

Systemic bw - CBC, Chem, SAA

Radiograph all enlarged joints

How can you dx orthopedic infections in foals?

WBC less than 5000

TP less than 2.0g/dL

SAA 20mg/l - or below

What should normal joint fluid look like?

Culture and sensitivity

What is the gold standard for dx of S and E type orthopedic infections?

Joint effusion/ infection - fibrin and fluid pockets seen

What is the u/s identifying?

Broad spectrum - pen G (Can go to oral after 10days after clinical signs)

Local tx

Banamine

Ulcer prevention - always!!!

How is systemic foal Orthopedic infections Treated?

48hrs after NSAIDS have been d/c

When should you discontinue antibiotics for systemic S and E types of Orthopedic infections?

Culture

Lavage (1-3L)

ABX (IV regional for 3 days, PMMA beads, R-gel)

IA HA

How is local S and E types of orthopedic infections treated?

Culture

ABX (IV regional for 3 days, PMMA beads, R-gel)

How are local type P orthopedic infections treated?

Flush from different angles to get all the fibrin out and make sure no corners are missed

Ex. above and below patella in stifle infection

What should you remember when lavaging a joint?

Tourniquet

Inj ABX slowly into a vein

Leave for 30 mins

Tx vein w/ topical anti-inflammatories and bandage

How is IV regional perfusion?

Antibiotic impregnated beads that are placed in a joint (must be removed)

What is PMMA?

Sx debridement

What tx for types E and P can be done?

Arthroscopy - fibrin likely too hard and needs removed

-potentially leave open to drain

If you are unable to lavage a joint what should you do?

Hip - infection likes to hide

If the joint looks like it is healing but is still lame where should you check?

Umbilical infection - can travel through umbilical vein and travel to liver

What is a common cause of orthopedic infection in foals?

Dissect vein out and attach stump to skin so it can drain and be flushed w/ saline

If the umbilical vein is infected to the liver what should you do?

Puncture wounds/ inj

(Rare hematogonous spread)

When do adults typically get orthopedic infection?

Tenoscopy/ synovectomy

Drain

Poss cut annular ligament

How do you tx a septic tenosynovitis?

Trauma to bone (kick) causing a disruption of blood supply to the cortex leading to necrosis that will form a draining tract to push little bone out

What is a sequestrum?

Chronic non-healing wounds over bones

When should we suspect a sequestrum?

Long term ABX

What is conservative tx for sequestrums?

Sx debridement and removal - make sure its loosened

-Can be done standing

-Debride enter tract

What should be done for more serious sequestrums?

a severe infection of bone, bone marrow, and surrounding soft tissue.

What is osteomyelitis?

Biofilms on plates

Long procedures = more time open

Why can animals get post-op infections?

Will see radiolysis above and below implant

How can you tell there in a bone infection with an implant?

ABX prophylactics

Lavage sx site w/ abx contadini fluids

ABX impregnated materials (PMMA, Plaster of Paris)

How is orthopedic infection prevented when applying sx implants?

Lamness lasting longer than expected

Pain not responding to analgesic

Swelling/ inflammation

Drainage

Fever of unknown origins

How do you dx an orthopedic infection post-op?

Remove and debride in sx

How do you tx an unstable infected implant?

Leave implant and do ABX therapy

How do you tx a stable infected implant?