5.1 Timing of surgery

5.1.1 PREOPERATIVE ASSESSMENT

Patients should be fully evaluated before surgery. Any short, unavoidable, delay can be used to gain improvement in clinical condition, particularly restoration of circulatory volume, and to improve chronic medical conditions.⁶⁵ Short delays prior to surgery may be justified for the correction of such conditions as hypo- and hyperkalaemia, poorly controlled cardiac failure or diabetes, significant anaemia, and for the investigation of cardiac murmurs. However, it is important not to chase unrealistic medical goals with resulting delay. For example, it is not considered appropriate to delay surgery because of infective pulmonary conditions, as real improvement is unlikely in the presence of continued immobility and pain. Evidence level 4

Bone quality should be assessed, especially the possible existence of osteoporosis, osteomalacia or secondary malignant deposits.

5.1.2 EFFECT OF DELAY ON PATIENT OUTCOMES

As well as causing distress to the patient, delay in operative fixation is associated with increased morbidity and mortality, and with reduced chance of successful internal fixation and rehabilitation.^{66, 67} A delay of more than 24 hours between admission and operative fixation of fracture has been shown to be associated with increased mortality.⁶⁶ Better functional results at three months have been shown when the mean delay to surgery was 29 hours compared to 57 hours.⁶⁷ Early surgery (within 24 hours) reduces the risk of deep vein thrombosis (DVT)⁶⁸ and of fatal pulmonary embolism (PE) after hip fracture.⁶⁹ Delay in surgery may also lead to an increased incidence of pressure damage.⁷⁰ Surgery should be performed as soon as the medical condition of the patient allows, provided that appropriate staffing and facilities are available.^70,71,72 However, it has also been demonstrated that surgical treatment conducted as a night-time emergency increases mortality.^65,73 Evidence level 2+

Patients should be operated on as soon as possible (within 24 hours), during standard daytime working hours, including weekends, if their medical condition allows.

Delay to surgery is common,⁷⁴ and when it is due to inadequate facilities or poor organisation rather than any medical reason, the underlying problems should be addressed, and solutions identified by the clinicians and hospital management.

5.2 Preoperative traction

A Cochrane review has examined the use of traction (both skin and skeletal) applied to the injured leg from the time of admission until surgery.⁷⁵ This time-honoured practice is intended to relieve pain and make subsequent surgery easier. Data from the six trials included in the latest update to the review was limited, for instance in the recording of long term complications such as the rates of avascular necrosis of the femoral head or fracture healing. However there was no evidence of any benefit in pain relief or fracture reduction from the routine use of preoperative traction in hip fracture patients. The small numbers and limitations of the studies cannot exclude possible advantages of traction for specific fracture types. Evidence level 1+

Similarly, further larger studies would be needed to assess more clearly the risks of complications from traction, such as pressure sores.

The routine use of traction (either skin or skeletal) does not appear to have any benefit and is not recommended prior to surgery for a hip fracture.

Foam gutter splints can be used to alleviate heel pressure.

5.3 Prophylaxis against infection

Patients with hip fractures are also at risk of infections of the chest, urinary tract, and wound.⁷⁶ Although bacteriuria is common on admission in patients with a hip fracture, it is very rare for the same organism to be associated with a postoperative wound infection.⁷⁷

A systematic review of randomised trials⁷⁸ indicates that the administration of antibiotic prophylaxis in patients undergoing surgery for a hip fracture is associated with a reduced incidence of superficial and deep wound infection, urinary tract infection and respiratory infection. Evidence level 1+

The antibiotic should be given as a single dose intravenously at anaesthetic induction.⁷⁸ However, if surgery takes longer than two hours or there is blood loss greater than two litres (which are both unlikely during hip surgery but possible in complex cases), a second dose may be administered during the operation.⁷⁹

All patients undergoing hip fracture surgery should receive antibiotic prophylaxis.

Bacteriuria should not be a reason to postpone surgery for hip fracture.

5.3.1 METHICILLIN RESISTANT STAPHYLOCOCCUS AUREUS

Methicillin Resistant Staphylococcus Aureus (MRSA) infection poses substantial problems for hip fracture patients. Patients may be admitted with MRSA colonisation or infection. Local hospital guidelines should be written for the detection, management, decolonisation and treatment of MRSA.⁸⁰

Infected or colonised patients should be isolated by following hospital infection control guidelines in consultation with the infection control team.

Active infection should be treated in consultation with Infection Specialists.

Decolonisation should not be attempted before all wounds are healed and any urinary catheter removed.

5.4 Antithrombotic prophylaxis

Antithrombotic prophylaxis is discussed in the SIGN guideline on prophylaxis of venous thromboembolism.⁸¹ The following is extracted from this document.

Hip fracture surgery carries high risks of asymptomatic deep vein thrombosis (DVT) (45%), symptomatic DVT (1-11%), symptomatic pulmonary embolism (PE) (3-13%) and fatal PE

(1-7%) in the absence of venous thromboembolism (VTE) prophylaxis.⁸² The pilot SIGN guideline on thromboprophylaxis,⁸³ considering published evidence up to early 1994, identified traumatic (e.g. hip fracture) orthopaedic surgery as "high risk" in the absence of prophylaxis. However, the recent literature has challenged the view that fatal PE is common. A recent review has highlighted the declining incidence of fatal PE in major orthopaedic surgery, due to increasing use of spinal or epidural anaesthesia (see section 6.2), early mobilisation, and use of mechanical prophylaxis.⁸⁴

5.4.1 MECHANICAL PROPHYLAXIS

A meta-analysis of four randomised controlled trials involving 422 patients of mechanical methods (two trials of intermittent pneumatic compression (IPC) and two of foot pumps; no trials of graduated elastic compression stockings (GECS) were identified) observed that the incidence of asymptomatic DVT was reduced from 19% to 6% (NNT=7.2).⁸⁵ There was insufficient data to establish the effects of these devices on symptomatic VTE or mortality. In the PEP trial,⁸⁶ use of GECS (by 30% of patients, non-randomised) was not associated with reduction in symptomatic VTE. Evidence level 1+

Mechanical prophylaxis (IPC or foot pumps) should be considered to reduce the risk of asymptomatic DVT after hip fracture. There is no evidence for efficacy of GECS in hip fracture patients.

5.4.2 ANTIPLATELET DRUGS (ASPIRIN)

A meta-analysis of randomised controlled trials (mainly the PEP study of aspirin⁸⁶) in patients undergoing surgery for hip fracture observed that aspirin reduced the risk of asymptomatic DVT (42% to 36%), symptomatic DVT (1.5% to 1.0%), all PE (1.6% to 0.8%) and fatal PE (0.8% to 0.4%), with no effect on total mortality. The excess risk of bleeding was small (one additional transfused bleed per 1,000 patients who were not receiving concomitant heparin prophylaxis).⁸⁶ Evidence level 1++

All patients with hip fracture should receive aspirin (150 mg orally, started on admission and continued for 35 days) unless contraindicated.

5.4.3 HEPARINS

A meta-analysis of unfractionated heparin (UFH) and low molecular weight heparin (LMWH) in hip fracture surgery showed that heparins reduced the risk of asymptomatic DVT from 39 to 24% (NNT=6.5). Unlike elective hip arthroplasty, no studies of recurrent asymptomatic DVT (venography at 4-5 weeks) or prolonged prophylaxis were identified. There was insufficient data to establish the effects of heparins on symptomatic VTE, mortality, or bleeding.⁸⁵ Evidence level 1++

In a multivariate analysis of predictors of death in a multicentre regional audit, mortality was lower among patients receiving pharmacological prophylaxis for VTE.⁷⁶ However, use of heparin prophylaxis (18% UFH, 26% LMWH, non-randomised) was not associated with reduction in symptomatic VTE in the PEP trial.⁸⁶ The additional benefit of UFH or LMWH compared to routine early mobilisation, mechanical prophylaxis and aspirin is therefore unclear.⁸² Evidence level 1++, 3

Heparin should be reserved for selected patients at high risk of VTE after hip fracture due to: multiple risk factors* contraindications to routine mechanical prophylaxis and/or aspirin.

* More than one of the following: age >80 years, obesity (BMI >30 kg/m2), varicose veins, previous VTE, thombophilias, heart failure, recent MI or stroke, severe infection, inflammatory bowel disease, nephrotic syndrome, polycythaemia, paraproteinaemia, Bechet's disease, paroxysmal nocturnal haemoglobinuria, hormone replacement therapy, tamoxifen, paralysis, malignancy.

5.4.4 ORAL ANTICOAGULANTS AND DEXTRANS

These methods also reduce the risk of VTE after surgery,⁸⁷ but are not widely used in the UK⁸⁸ due to logistic problems, and risks of bleeding (oral anticoagulants) and anaphylaxis (dextrans).

5.5 Fluid and electrolyte balance

Fluid and electrolyte balance problems are common in the course of hip fracture management in the elderly. Awareness of these risks is part of preoperative assessment. At particular risk are older, frailer patients, especially those in whom identification of hip fracture and hence admission has been delayed.⁸⁹ Evidence level 4

Patients should have clinical and laboratory assessment of possible hypovolaemia and electrolyte balance, and deficiencies appropriately and promptly corrected.

5.6 Supplementary oxygen

It has been reported that persistent hypoxia may be present in all hip fracture patients from the time of admission until up to five days postoperatively.^90,91 Evidence level 1+, 3

Oxygen saturation should be checked on admission. Supplementary oxygen should be administered to all patients with hypoxaemia.