Evidence-based guidelines for fixing broken hips: an update

Hip fracture is a commonly encountered clinical problem, with the prevalence of proximal femur fractures in Australia predicted to double between 1996 and 2026.1 Hip fractures are associated with a 12-month mortality rate of about 25%, and most patients who survive do not return to the level of mobility and independence they had before the fracture.2,3

Evidence-based clinical practice guidelines, based on the published literature up to December 1995, were published in the Journal in 1999.4 These guidelines were implemented and evaluated in a study utilising clinical pathway methodology.5 In brief, we were able to show that implementing the guidelines changed some processes of care, but that there was minimal impact on longer-term outcomes (4-month mortality and nursing home placement).

Here, we update the 1996 guidelines. Hip fractures should be treated according to the most up-to-date evidence to ensure the best possible outcomes and optimal utilisation of limited resources.

We identified randomised controlled trials (RCTs) and meta-analyses of interventions for hip fracture management by searching electronic databases (MEDLINE, EMBASE and CINAHL) from January 1996 to September 2001. The Cochrane Database of Systematic Reviews was searched up to Issue 2, 2002. Search terms were “hip fractures” together with specific interventions, which had been identified in the previous review.4 Searches were limited to RCTs, meta-analyses, subjects aged 50 years or over, and proximal hip fractures not related to metastatic disease. Primary studies which had already been included in Cochrane Collaboration reviews at the time of our literature searching were not re-reviewed.

All articles were read independently by two assessors. Results and data on study quality were recorded on a pro forma developed according to Cochrane Collaboration guidelines for assessment of study quality.6 Disagreements were resolved by a third, independent assessment and a consensus meeting.

Individual study results and an assessment of the quality of each study’s methods were summarised in a table format with author, year, number of subjects, interventions tested, ranking of bias (low, moderate, high), adequate concealment of allocation of patients to groups, and summary of results with relative risk, 95% confidence intervals and conclusions regarding treatment.

These tables were then used to generate a summary for each intervention, which included the previous recommendation, a summary of the evidence provided by the new studies and any new recommendations.

Evidence-based guidelines were then developed, with National Health and Medical Research Council (NHMRC) levels of evidence listed for each recommendation.7

Ninety-three new studies were identified, of which 82 met our inclusion criteria. Eleven studies were excluded for one of the following reasons: the majority of patients were involved in high-impact trauma (1 study),8 they were not randomised trials (5 studies),9-13 and they were published in a language other than English and did not meet our other inclusion criteria (5 studies).14-18 Fifteen studies were not re-read, as they were included in Cochrane Collaboration reviews at the time of searching.19-33

No new RCTs or meta-analyses were found relating to the following interventions: time to surgery, oxygen therapy, pressure-gradient stockings, and urinary catheterisation.

Two new issues in hip fracture management — postoperative blood transfusion and surgical swabs — were included in our review, because studies addressing these issues are now avail-able.

The updated evidence-based guidelines are summarised in the Box (page 492).

The NHMRC recommends regular review of established guidelines.7 Our study updates previously published guidelines for the treatment of proximal femoral fractures.4

Although we identified a number of new studies and Cochrane Collaboration reviews, there have been few changes to previous recommendations. Recommendations regarding nutritional status and surgical fixation of fractures have been altered to incorporate new evidence. We have also included new recommendations for postoperative blood transfusion and surgical swabs (Box).

Our recommendations are similar to those of the Scottish Intercollegiate Guidelines Network (SIGN), which updated its hip fracture management guidelines in 2002.120 One difference is in the recommendation for thromboprophylaxis. The SIGN guideline recommends that all patients receive aspirin unless contraindicated. Having found little evidence for the benefit of heparin for the clinically important outcomes of pulmonary embolism, mortality, and bleeding, and benefit over routine early mobilisation, mechanical prophylaxis and aspirin, the SIGN group concluded that heparin be reserved for patients at high risk of venous thromboembolism. Patients are considered high risk according to multiple risk factors or contraindications to routine mechanical thromboprophylaxis and/or aspirin.

Although we have reviewed the same evidence as the SIGN group, we would argue for the use of either low molecular weight heparin (LMWH) or unfractionated heparin in most patients. Patients undergoing surgery for hip fracture are known to be at high risk for venous thromboembolism, with comparatively high rates of deep venous thrombosis and pulmonary embolism.121,122 In the East Anglian audit, the use of pharmacological prophylaxis was associated with a reduced risk of fatal pulmonary embolism.123 A meta-analysis of heparin in hip-fracture surgery has shown that heparin is protective against deep venous thrombosis, with a relative risk reduction of almost 60%. While this did not extend to a significant protective effect against pulmonary embol-ism, we would expect that with larger trials there would be sufficient statistical power to demonstrate this. Indeed, meta-analysis of orthopaedic and surgery trials has shown that heparin reduces the risk of pulmonary embol-ism, with similar risk reductions across different surgical specialties.124 Extrapolating these data to hip-fracture patients, we would expect the benefit to be high in these patients, in whom the rates of pulmonary embolism are high.

According to the recommendations of SIGN, a significant number of patients would be receiving aspirin as their only pharmaceutical prophylaxis against pulmonary embolism, even though LMWH has been shown to be superior to aspirin in preventing deep venous thrombosis, the precursor to pulmonary embolism.52

Despite a number of studies investigating the use of heparin for thromboprophylaxis in hip-fracture patients, it is apparent that its role has not yet been clearly defined.

Regional anaesthesia is still recommended for most patients during proximal femoral fracture fixation. Potential complications which may have limited its use include hypotension and spinal haematoma. There is new evidence to support a number of interventions aiming to reduce the incidence of hypotension.62-66,68 In the recent Pulmonary Embolism Prevention trial,56 no occurrences of spinal haematoma were documented in the 4603 hip-fracture patients who received regional anaesthesia (including those with and without aspirin and other anticoagulant therapy).

Our study has some limitations. Guidelines date quickly. In developing wide-ranging systematic reviews and guidelines, it inevitably takes consider-able time to review the primary studies and formulate recommendations. Publishing in a peer-reviewed journal also adds to the time from literature search to date of publication. Summarising complex issues in a review, such as this, can also be difficult. Although guidelines provide a useful resource for clinicians, it is still unclear whether the use of evidence-based guidelines improves outcomes.

Our study has updated previously published guidelines for the management of proximal femoral fractures. Reviewing the evidence accumulated in the 6 years since the last guidelines were produced required substantial effort. Since the development of the original guidelines, the Cochrane Collaboration Musculoskeletal Injuries Group has published reviews or protocols for planned reviews addressing most areas covered by our guidelines. Future updates may be able to draw on the reviews of this group rather than review studies individually, making the future guideline development a more manageable task. Guideline updates also require adequate financial resourcing to identify and appraise all relevant material.