**2. Preoperative evaluation**

A detailed history and clinical examination is necessary in all cases of hip fractures. Particular care must be made to identify pre-existing medical comorbidities and regular anticoagulants being taken by the patient. A comprehensive discussion should take place with the patient and their relatives in relation to any proposed management strategy. Morbidity and mortality associated with femoral neck fracture care should be discussed. Mortality is 10% within the first 30 days reflecting the compromised status of many of these patients. Mortality rates rise to approximately 40% at 12 months.

Examination may reveal a shortened, externally rotated lower extremity. The neurovascular status of the lower limb should be evaluated and documented, and a secondary survey should be completed to rule out associated injuries.

Appropriate imaging should take the form of plain film radiographs of the pelvis and femur in anterior-posterior and lateral planes. The pelvis should be held in neutral with both femurs clearly visible and the feet held in internal rotation. Preoperative estimates of magnification on X-rays are frequently incorrect and can lead to mismatching of implant sizes, limb length discrepancies, and disturbance of the biomechanical parameters of the hip joint. The magnification factor for pelvic imaging normally ranges from 109 to 128%. Radioopaque calibration spheres can be sited midline to femurs and proximally towards the pubic symphysis to aid in digital templating of the preoperative X-rays. The contralateral hip should be used as a surrogate for templating in the trauma setting. Digital templating is essential to determine the location of the neck cut, size of the prosthesis, appropriate offset, and depth of insertion. If there is a concern for pathological fracture, appropriate imaging of the whole femur should be obtained in the first instance, and intraoperative histological samples should be sent for analysis.

All patients with a hip fracture should have a preoperative electrocardiogram, and in those over the age of 65, a chest X-ray should also be performed. It has been determined by the Association of Anaesthetists of Great Britain and Ireland (AAGBI) that a preoperative echocardiogram should not delay the passage of a patient with a hip fracture to theatre and should rather be performed, if necessary, during the postoperative period. Routine preoperative blood tests may reveal preoperative anaemia which occurs in 30–40% of patients and may be attributable to the fracture itself, haemodilution or a pre-existing condition. The acute response to trauma may lead to neutrophilia or leucocytosis. It is noteworthy that electrolyte imbalances are not uncommon in this cohort of patients, especially hyponatremia and hypokalemia. Hyperkalemia may also be an indicator of rhabdomyolysis occurring secondary to a prolonged period of immobilisation following the initial traumatic event.

Neuraxial anaesthesia is often the preferred form of anaesthesia for treatment of femoral fractures. The suspicion of aortic stenosis on clinical examination often precludes neuraxial anaesthesia. Despite this, general anaesthesia is also a safe option, and the Sprint Audit has shown no significant difference in mortality between these modes of anaesthesia [29]. Combined neuraxial anaesthesia and general anaesthesia has shown a trend towards increased mortality. This is most likely related to the 'double hit' hypotensive effects of both modalities of anaesthesia.
