Fracture Complications Flashcards
Fracture complications
Non-healing
Implant failure
Infection
OA
Delayed union
Fracture that has not healed when adequate period of time has elapsed for that particular fracture to achieve union
Non-union
Cessation of all reparative processes of bone healing
Union not possible without intervention
*Failure of progressive change in radiographs for at least 3 mo
Causes of delayed/non-union
Inadequate reduction
Inadequate stabilization
Loss of blood supply
Infection
Systemic factors
Blood supply in bones
Separation blood supply for epiphysis and metaphysis
Periosteum highly vascular
Main blood supply: nutrient artery
Metaphysis anastomose with diaphysis
Periosteal supply outer 1/3 of cortex
Post-fracture blood supply
Primary: extra osseous - surrounding soft tissue to early callus
Secondary: medullary takes over after some healing
Weber-Cech Classification of Non-Union Fractures
Viable (biologically active, variable proliferative reaction)
Non-viable (avascular, non-reactive) - less common
Viable Non-unions
Hypertrophic
Moderately Hypertrophic
Oligotrophic
Non-viable non-unions
Dystrophic
Necrotic
Defect
Atrophic
Viable hypertrophic non-union
“Elephant foot”
Abundant callus unable to bridge gap
Cause: inadequate stabilization/excessive motion
Viable moderately hypertrophic non-union
“Horse foot”
Moderate callus that doesn’t bridge fracture site
Somewhat subjective (relative to hypertrophic classification)
Usually due to inadequate stabilization/excessive motion
Viable oligotrophic non-union
Viable without radiographic evidence of biological activity (hard to distinguish from non-viable)
Callus absent/minimal
Fuzzy/hazy appearance of bone ends
Cause: excessive motion + lack of cellular activity; loose implants in area of fracture healing
Non-viable dystrophic non-union
One or both sides of fracture ends are non-viable
Fracture fragment that has healed to one main fragment but not the other
Most often distal radius/ulna of toy/mini breeds
Non-viable necrotic non-union
Fracture fragment with no blood supply (sequestrum)
Sharp edges - become more sclerotic with time
Non-viable defect non-union
Fracture gap too large for normal biological activity
> 1.5 x bone diameter
Open fractures, high velocity gun shot fracture
Non-viable Atrophic non-union
End result of other non-viable non-unions
Resorption/rounding of edges, complete cessation of osteogenic activity
Most difficult to resolve
Clinical signs of delayed/non-union
Persistence of:
Pain at fracture site
Lameness
Disuse atrophy of limb
Movement at fracture site
Radiographic signs of non-union
Fracture gap
No activity at fracture ends
Obliteration of marrow cavity
Osteopenia of surrounding bond
Non-bridging callus
Treatment of delayed/non-unions
Allow more time
Increase rigidity of stabilization
Enhance blood supply
Bone graft
Treat underlying condition (infection, gap, metabolic health of animal)
Surgery on a delayed/non-union
Apply rigid fixation
Culture + sensitivity testing —> antibiotics
Cancellous bone graft (blood supply)
Malunion
Fracture that heals in a non-anatomic position
Results of malunion/non-union
Angular limb deformities
Limb shortening
Degenerative joint disease
Disuse muscle atrophy
Gait abnormalities
Never weight bears/uses limb —> amputation
Goals of post-op fracture assessment
Determine if adequate repair method chosen applied
Confirm progression of healing
Guide for clinical recommendations
Detect complications ASAP
Surgeon growth
Radiographs of fracture sites
Joints above + below
Two orthogonal views
Assess quality/technique, soft tissue, fracture repair/healing/implant integrity
