Complications following surgery for hip fracture

Background Over 10 million hip fractures occur worldwide every year. In the United Kingdom (UK) alone, it is estimated that there are 80,000 hip fractures annually. Mortality, disability, and healthcare costs are substantial after a hip fracture, for which the development of complications may be a key contributory factor. However, the risks of complications are poorly quantified and vary widely across the literature, ranging from 10% to 40%. Given that complications are common, identifying the associated risk factors is an important step towards preventing them from occurring. Furthermore, quantifying their influence on quality of life (QoL), mortality, and health and social care costs will enable the prioritisation of the resources towards interventions that are of high feasibility and impact. Aim and objectives The aim of this dissertation was to understand the interaction between complications, their respective risk factors, and their influence on the patient, and health and social care system. The objectives were to: i. Estimate the risk of complications after hip fracture (Chapters 2 and 4) ii. Identify risk factors associated with the development of complications after hip fracture (Chapter 5) iii. Evaluate the influence of complications on outcomes after hip fracture (Chapter 6) iv. Quantify the costs associated with complications after hip fracture (Chapter 7) Methods A systematic review and meta-analysis of the hip fracture population was conducted to determine the literature-reported risk of complications after hip fracture. Data from the World Hip Trauma Evaluation (WHiTE) study was analysed to estimate the risk of complications, identify risk factors associated with these complications, evaluate the influence of these complications on QoL and mortality, and quantify the health and social care costs incurred due to these complications. The WHiTE study was a multi-centre, prospective observational study that measured outcomes in a comprehensive cohort of older adults with hip fractures in the UK. Results The systematic review and meta-analysis of 95 studies of 2,521,300 hip fracture patients found that the risks of complications were higher than conventional literature-reported estimates. For surgery-specific complications, the 365-day risk of prosthesis dislocation was 1.1%, fixation failure 1.8%, and peri-prosthetic or peri-implant fracture 2.2%; and the 30-day risks of re-operation for any indication was 2.3% and surgical site infection (SSI) 1.7%. For general complications, the 30-day risk of acute kidney injury was 1.2%, blood transfusion 25.6%, lower respiratory tract infection 4.1%, urinary tract infection 7.0%, cerebrovascular accident 0.8%, myocardial infarction 2.0%, and venous thromboembolism 2.2%. Among the 24,523 patients included in the WHiTE study, the risks of surgery-specific and general complications at 120-days after hip fracture were 7.0% and 30.7%, respectively. Several associated risk factors were identified including non-modifiable factors such as age, sex, and co-morbid state, and modifiable factors such as operation type, timing of surgery, and timing of mobilisation post-operation. The development of complications had a significant influence on QoL. Patients who had a prosthesis dislocation, deep SSI or revision surgery experienced similar loss of QoL to those who had a cerebrovascular accident or myocardial infarction. The total health and social care cost for hip fracture across the cohort in the first four months after the injury was £388 million, which was equivalent to £2 billion when projected to the UK population. Complications were associated with higher expenditure, with prosthesis dislocation, deep SSI and revision surgery incurring the greatest health and social care costs. Conclusion The development of complications is likely to be an important mediating factor between risk factors and poor outcomes following a hip fracture. Preventing these complications from occurring can potentially improve patient outcomes and reduce healthcare expenditure. These findings are an important step towards quantifying the scale of problem and developing scope for future research into this topic.