Ortho complications (Dujo)

Question 1

Tension side depends on

Answer 1

• overlying soft tissue
• fracture
• forces action on bone

*exceptions: big defect

Question 2

Delayed unions

Answer 2

• Fracture takes longer to heal than anticipated
  
  • adequate time but incomplete healing
  • healing progressing slower rate than expected
• bone should be healed by
  
  • 3-4 months in adults
  • 1-2 months in growing animals

Question 3

Delayed unions

biological causes

Answer 3

• Poor vascularity
  
  • usually secondary to trauma
  • most common biological cause
• presence of infection
• Escessive postoperative activity
• Systemic dz
• Drugs

Question 4

Delayed union

Biological causes

Systemic dz

Answer 4

• Examples of systemic dz
  
  • Primary hyperthyroidism
  • Hyperadrenocorticism
  • Diabetes mellitus
  • Renal dz
  • Intestinal malabsorption

Question 5

Delayed union

Biological causes

Drugs

Answer 5

• Examples of drugs
  
  • corticosteroids
  • antineoplastic drugs
  • anticonvulsant drugs

Question 6

Inadequate fracture fixation can result in

Answer 6

• Instability and motion
  
  • results: prevention of callus maturation and bone healing

Question 7

DX of delayed union

Answer 7

• Slightly subjective
  
  • serial rads
• Eval mechanical and biological factors
  
  • fracture margins distinct
  • pseudoarthrosis
  • sealed marrow cavity
  • arrest or regression of healing

Question 8

TX of delayed unions

Answer 8

• Autogenous cancelous bone graft
• Vascularized graft or bone forage
• More rigid fixation
• Remove implants in infection
  
  • make sure there is enough healing

Question 9

Nonunion

Answer 9

• All healing processes have stopped with bone unhealed
• two main types
  
  • viable
  • nonviable
• surgical intervention necessary
• etiology same as delayed union
  
  • plus seequestration

Question 10

Viable

(biologically active)

Answer 10

• Hypertrophic
• Slightly hypertrophic
• Oligotrophic

Question 11

Nonviable

(Biologically inactive)

Answer 11

• Dystrophic
• Necrotic
• Defect
• Atrophic

Question 12

Intraoperative findings of non-unions

Answer 12

• usually combo of
  
  • fibrous tissue
  • instability

Question 13

Hypertrophic non unions

Answer 13

• abundant hypervascularized callus
• usually seen in unstable fractures

Question 14

mildly hypertrophic nonunions

Answer 14

• Inadequate callus
• mild sclerosis of medullary cavity at fracture site
• associated with rotational instability

Question 15

Oligotrophic nonunions

Answer 15

• No visible callus
  
  • ends of medullary cavity sealed at fracture site
  • rounding of fragment ends
  • fibrous tissue and blood vessels between the fragment edges
  • still capable of a biologic response
  • seen in significant displacement of fracture fragments

Question 16

nonviable nonunions

dystrophic nonunion

Answer 16

• dystrophic nonunion
  
  • occur when secondary fragment has healed
• main fragment is healed and devoid of callus

*kind of looks like the oligotrphic non-union

Question 17

Nonviable nonunions

Necrotic nonunion

Answer 17

• Seen in highly comminuted fractures in poorly vascularized areas
• Major fragments eventually die without being incorporated in the callus

Question 18

Nonviable nonunions

Defect nonunion

Answer 18

• Results from
  
  • loss of fragments at time of injury or
  • resorption of fragment

Question 19

Nonviable nonunions

Atrophic nonunion

Answer 19

• Atrophic nonunion
  
  • dystrophic, necrotic and defect nonunions can all lead to atrophic nonunions
  • characterized by bone resorption and osteoperosis

Question 20

Factors leading to nonunion

Answer 20

• Infection
• Inadequate fracture reduction
• soft tissue disruption
• poor surgical decision making

Question 21

DX of nonunions

Answer 21

• Serial rads 3-6 weeks apart
• compare for
  
  • periosteal bone formation
  • callus formation
  • changes in gap width
  • blunting of bone fragments

Question 22

Radiographic signs of nonunion

Answer 22

• Sclerosis of bone ends at fracture site
• no progression/changes over 3 months
• progressive bowing at fracture site
• bone atrophy
  
  • fracture ends become thinner and reabsorb
• excess callus around fracture site with radioluscent lines in callus

Question 23

TX guidelines nonunion

Answer 23

• Consider underling causes
  
  • lack of stability
  • lack of blood supply
• debridement of necrotic bone
• open medullary canal
• rigid fixation
• autogenous bone graft
  
  • can add allograft

Question 24

Malunion

Answer 24

• Healing of bone in abnormal position
  
  • functional
  • nonfunctional
• causes
  
  • inadequate fracture reduction/stabilization
  • nonanatomic positioning
• Resulting deformities
  
  • angular
  • rotational
  • distracted
  • over-riding

Question 25

Treatment of malunion

Answer 25

• corrective osteotomy
• realignment
• rigid fixation
• surgery
  
  • imparied limb function
  • stenosis of pelvic canal
  • jaw malocclusion
  • patellar luxation

Question 26

Osteomyelitis

Answer 26

• Hematogenous spread
• spread from adjacent soft tissue infection
• secondary to penetrating wound
• infection associated with contaminated implant

Question 27

Pathophys of osteomyelitis

Answer 27

• Factors
  
  • blood supply
  • soft tissue disruption
    
    • tissue necrosis
• Bacteria form biofilm
  
  • adhere to implant
  • host defense can’t adequately reach bacteria
  • antibiotics less effective against biofilms

Question 28

Osteomyelitis

organisms

Answer 28

• staph
• fungal
  
  • blasto
  • crypto
  • coccidiomycosis
  • nocardia
  • actinmyces

Question 29

Radiographic findings

Osteomyelitis

Answer 29

• Soft tissue swelling
• irregular periosteal reaction far from fracture line
• long zone of transition
• can resemble a tumor

*To diagnose do bone core, submit for cultures

Question 30

Sequestrum

Answer 30

• avascular/nonviable bone fragment
• typically has sharp margins
• can impede healing
• can cause disfunction

Question 31

Ivolucrum

Answer 31

• Periosteal reaction around a sequestrum
  
  • membrane around sequestrum

Question 32

Cloaca

Answer 32

• Opening ininvolucrum
  
  • results in drainage

Question 33

External fixaters are really good at

Answer 33

• Preserving the biology

Question 34

Bandage disasters

Answer 34

• Ischemic bandage injuries
  
  • loss of tissue
  • excessive skin compression
  • tourniquet effect

Question 35

causes bandage disasters

Answer 35

• Inadequate application of the bandage
• Insufficient padding
• Pre-existing vascular injury
• Bandage changes not frequent enough

Question 36

Quadriceps contracture

Answer 36

• young growing dogs
• femoral fracture
• excessive fibrous tissue
  
  • rigid and unfixable extension
• secondary to
  
  • quadriceps muscle trauma
  • inadequate fixation and instability
  • prolonged immobilization

Question 37

Quadriceps contracture

Prevention

Answer 37

• Early fracture treatment
• Rigid fixation
• Early return to function
• Temporary immobilization

Question 38

Minimizing infection

Answer 38

• No reason to use antibiotics more than 24 hours post-op prophylactically
• Use
  
  • cefazolin 30-60 minutes prior to induction
  • then every 1.5-3 hours post-op
• Don’t be fast and sloppy in sx
  
  • be efficient and plan out sx

Question 39

Minimizing infection

Contaminated surgical site

Answer 39

• debride as much tissue as possible
• irrigate with saline
• obtain intraoperative cultures
  
  • positive cultures don’t mean a patient will develop an infection