Complications From Fractures

Fracture is a common event: most of us will experience at least one during a lifetime. In modern times, with medical and surgical assistance, the majority heal without problem or significant loss of function. However, complications can pose risk to limb and even life.

Complications of fractures tend to be classified according to whether they are local or systemic and when they occur - early or late.
Early complications occur at the time of the fracture (immediate) or soon after. Early local complications tend to affect mainly the soft tissues.

Fractures of the limbs can cause severe ischaemia, even without damage to a major blood vessel. Bleeding or oedema in an osteofascial compartment increases pressure within the compartment, reducing capillary flow and causing muscle ischaemia. A vicious circle develops of further oedema and pressure build-up, leading swiftly to muscle and nerve necrosis. Limb amputation may be required if untreated.
Compartment syndromes can also result from:

• Crush injuries caused by falling debris or from a patient’s unconscious compression of their own limb.
• Swelling of a limb inside an over-tight cast.

Compartment syndrome can occur in any compartment, e.g. the hand, forearm, upper arm, abdomen, buttock, thigh, and leg. 40% occur following fracture of the shaft of the tibia (with an incidence of 1-10%) and about 14% following fracture of a forearm bone. Risk is highest in those under 35 years.²

Presentation

• Signs of ischaemia (5 P's: Pain, Paraesthesia, Pallor, Paralysis, Pulselessness) - but diagnosis should be made before all these features are present. The presence of a pulse does not exclude the diagnosis.
• Signs of raised intracompartmental pressure:
  • Swollen arm or leg
  • Tender muscle - calf or forearm pain on passive extension of digits
  • Pain out of proportion to injury
  • Redness, mottling and blisters
• Watch for signs of renal failure (low-output uraemia with acidosis)

Where the diagnosis is uncertain, measure intracompartmental pressure directly. The pressure at which fasciotomy becomes mandatory is controversial.³

Management

• Remove/relieve external pressures
• Prompt decompression of threatened compartments by open fasciotomy
• Debride any muscle necrosis
• Treat hypovolaemic shock and oliguria urgently
• Renal dialysis may be necessary

Complications

• Acute renal failure secondary to rhabdomyolysis
• DIC
• Volkmann's contracture (where infarcted muscle is replaced by inelastic fibrous tissue)

This is a relatively uncommon disorder that occurs in the first few days following trauma with a mortality rate of 10-20%.⁴ Fat drops are thought to be released mechanically from bone marrow following fracture, coalesce and form emboli in the pulmonary capillary beds and brain, with a secondary inflammatory cascade and platelet aggregation. An alternative theory suggests that free fatty acids are released as chylomicrons following hormonal changes due to trauma or sepsis.⁵ Risk of Fat Embolism Syndrome (FES) increases with number of fractures, but is also seen following severe burns, CPR, bone marrow transplant and liposuction.⁶

Risk factors

• Closed fractures
• Multiple fractures
• Pulmonary contusion
• Long bone/pelvis/rib fractures⁷

Presentation

• Sudden onset dyspnoea
• Hypoxia
• Fever
• Confusion, coma, convulsions
• Transient red-brown petechial rash affecting upper body, especially axilla

Management

• Supportive treatment
• Corticosteroid drugs (used in treatment, more controversial in prevention)
• Surgical stabilisation of fracture⁸

Non-union is where there are no signs of healing after >3-6 months (depending upon site of fracture). Non-union is one endpoint of delayed union. Malunion occurs when the bone fragments join in an unsatisfactory position, usually due to insufficient reduction.
Causes of delayed union include:

• Severe soft tissue damage
• Inadequate blood supply
• Infection
• Insufficient splintage
• Excessive traction

Causes of non-union are similar but also include:

• Too large a space for bony remodelling to bridge
• Interposition of periosteum, muscle or cartilage

Non-union occurs in approximately 1% of all fractures but is more common in lower leg fractures (19% non-union) or where there is motion at the fracture site.

Presentation

• Pain at fracture site
• Non-use of extremity
• Tenderness and swelling
• Joint stiffness (prolonged >3 months)
• Movement around the fracture site (pseudarthrosis)

Investigations

• Absence of callous (remodelled bone) or lack of progressive change in the callous suggests delayed union.
• Closed medullary cavities suggest non-union.
• Radiologically, bone can look inactive, suggesting the area is avascular (known as atrophic non-union) or there can be excessive bone formation on either side of the gap (known as hypertrophic non-union).

Management

Non-surgical approaches such as early weight bearing and casting may be helpful for delayed and non-union.
Surgical treatments include:

• Debridement to establish a healthy infection-free vascularity at fracture site
• Internal fixation to reducing and stabilize fracture.
• Bone grafting to stimulate new callous formation.

Myositis ossificans is where calcifications and bony masses develop within muscle and can occur as a complication of fractures, especially in supracondylar fractures of the humerus.⁹ It tends to present with pain, tenderness, focal swelling, and joint/muscle contractions. Avoid excessive physio, rest joint until pain subsides, NSAIDs may be helpful and consider excision after the lesion has stabilized (usually 6-24 months). It may be difficult to distinguish for osteogenic sarcoma.¹⁰

Sudeck's atrophy is a form of reflex sympathetic dystrophy (or complex regional pain syndrome type 1), usually found in the hand or foot. 89% of reflex sympathetic dystrophies follow trauma, notably fractures.¹¹ A continuous, burning pain develops, accompanied at first by local swelling, warmth and redness which progresses to pallor and atrophy . Movement of the afflicted limb is very restricted.
Treatment is usually multi-pronged:

• Rehabilitation - physio and occupational therapy to decrease sensitivity and gradually increase exercise tolerance.
• Psychological therapy
• Pain management - often difficult and with a disputed evidence-base. Approaches used are neuropathic pain medications (e.g. amitriptyline, gabapentin, opioids), steroids, calcitonin, IV bisphosphonates and regional blocks.¹²

Casts

• Pressure ulcers
• Thermal burns during plaster hardening
• Thrombophlebitis

Prolonged cast immobilisation, or 'cast disease', can create circulatory disturbances, inflammation, and bone disease resulting in osteoporosis, chronic oedema, soft-tissue atrophy, and joint stiffness. Good physiotherapy should avoid these problems.

Traction

Traction prevents patients mobilising causing additional muscle wasting and weakness. Other complications include:

• Pressure ulcers,
• Pneumonia/UTIs
• Permanent footdrop contractures
• Peroneal nerve palsy
• Pin tract infection
• Thromboembolism

External fixation

Problems include:

• Pin tract infection
• Pin loosening or breakage
• Interference with movement of joint
• Neurovascular damage due to pin placement
• Misalignment due to poor placement of the fixator