Complications of fracture repair Flashcards
(46 cards)
Factors to be considered when dealing with fracture complications
Immobilisation
Biology (blood supply, bone viability, periosteum integrity, marrow cells)
Infection
Others (severity of the trauma, defect size, patient related factors)
Direct bone healing
Absolute stability (<2% interfragmentary strain)
No gap or very small gap (<1mm)
Will not result in callus formation
Indirect bone healing
Relative stability (10% interfragmentary strain)
Can occur with larger gaps
Will result in callus formation
How to calculate strain
Strain = deltal L / L
= Gap movement / fracture gap
Delayed union
A fracture that has not healed in the time normally expected for that fracture type to heal
Non-union
Fracture healing stops and union will not occur without surgical intervention
(non-progression for 3mo after fracture should have healed)
Clinical signs of a delayed or non-union
Painful motion at the fracture site
Pseudoarthritis
Progressive deformity
Disuse of the limb
Muscle atrophy
Joint stiffness
Causes of delayed and non-union
Inadequate immobilisation
Inadequate reduction
Loss of blood supply
Infection
Loss of bone from trauma
What is the commonest cause of delayed or non-union?
Inadequate immobilisation of the fracture
Radiological appearance of delayed union
A radiolucent gap between fracture fragments, with a feathery or chewed up appearance of the fracture ends and moderate callus
Radiographic appearance of non-union
No radiological evidence of healing - no callus, ends of bone segment are rounded and the marrow cavity is sealed with dense (sclerotic) trabecular bone.
Bone ends can be enlarged (elephant foot) or narrowed (atrophic).
Two main groups of non-unions
Biologically acitve/viable non-unions
Biologically inactive/non-viable non-unions
Types of biologically active or viable non-unions
Hypertrophic (elephant foot)
Slightly hypertrophic type (horses foot)
Oligotrophic type
Types of biologically inactive or non-viable non-unions
The dystrophic type (torsion wedge)
The necrotic type (necrotic segment)
The defect type (big gap)
The atrophic type
Causes of hypertrophic non-union (biologically active)
Usually a complication of IM pinning of humeral and femoral shaft fractures - caused by rotation at fracture site
Can be a complication of loose cerclage wires or sequestra
A well-developed elephant-foot shaped callus develops which does not bridge the fracture gap
Biology of a hypertrophic non-union
The gap contains cartilage and fibrous tissue
There is sclerosis of the bone ends and later the medullary cavity becomes sealed.
Treatment of hypertrophic non-union
Rigid immobilisation preferably with a compression plate or anti-rotational ESF.
Cartilage and fibrous tissue between bone ends rapidly ossifies so it is not as necessary to freshen the ends or use a bone graft
Remove loose implants or sequestra - necrotic bone is yellowish white in appearance
Following debridement flatten out the ends so they can be compressed
Slightly hypertrophic non-union (horses foot)
Instability following plate fixation
Minimal callus formation
Oligotrophic non-union
No callus formation and the fragments are usually widely separated and joined by fibrous tissue only e.g. avulsion fractures
May benefit from adjusting the biological or mechanical environment
Dystrophic non-union (torsion wedge)
Seen as a complication of comminuted fractures where a poorly revascularised fragment or fragments impedes fracture healing
Necrotic non-union
Seen in commoinuted or infected fractures where non-viable fragments or sequestra at the fracture site impede healing
Defect non-union
A major defect in the bone caused by removal of fragments or sequestra which is too big to be bridged by the normal healing process.
Often seen after severe soft tissue injury or a loss of vascularity in the area - often become atrophic.
Treatment of viable non-union
Remove loose implants
Rigid immobilisation - preferably with a compression plate or with anti-rotational ESF
Biomechanical stimmuli (e.g. shockwave therapy) can stimulate bone healing
Don’t need ends freshening or bone grafts
Treatment of non-viable non-unions
Harder
Fracture site debridement - remove loose implants, sequestra, or unhealthy callus
Exposing viable bone ends - cut back 2-3mm creating two flat surfaces
Compression with DC plate
Opening medullary cavity
Bone graft
Stem cell therapy
Biomechanical stimuli
