Rationale and impact
These sections briefly explain why the committee made the recommendations and how they might affect practice.
The committee discussed the clinical evidence on total hip arthroplasty versus hemiarthroplasty. They agreed that although some studies showed greater benefits for total hip arthroplasty, this was not clinically or statistically significant for most outcomes. However, a combination of the clinical evidence and the health economic model developed as part of the guideline indicated that total hip arthroplasty may have some benefits and be more cost effective than hemiarthroplasty beyond 2 years. The committee noted that although recommendation 1.6.2 states that clinicians should offer arthroplasty (either total hip arthroplasty or hemiarthroplasty) to people with a displaced intracapsular hip fracture, hemiarthroplasty tends to be used more often than total hip arthroplasty. The evidence was not strong enough for them to recommend total hip arthroplasty for everyone with a displaced intracapsular fracture.
Based on their clinical knowledge and experience, the committee discussed how the long-term outcomes considered in the health economic model were important but may not be relevant to some people. For example, older people may not live long enough to experience the long-term benefits of total hip arthroplasty, and people who are not very mobile may be less concerned about the potential consequences of having a hemiarthroplasty, such as wear on the acetabulum. The committee agreed that hemiarthroplasty was a less complicated procedure than total hip arthroplasty and could result in lower dislocation rates and less blood loss.
The health economic evidence on the long-term cost effectiveness and potential clinical benefits of total hip arthroplasty led the committee to recommend that clinicians should consider the procedure for those who are most likely to benefit from it beyond 2 years. The list of criteria in the recommendation represents the past (a person's level of independence before the fracture), present (how they currently present in hospital and if they are fit for the procedure on that day) and future (how much they are likely to benefit beyond 2 years). Including this list gives clinicians more discretion over who to offer total hip arthroplasty to and prevents the procedure being offered to some people who may get the same, or more, benefit from hemiarthroplasty.
The committee discussed how some people with significant cognitive impairments may be at increased risk of dislocations and could be less likely to benefit from total hip arthroplasty. However, they agreed that the evidence for this was too limited to make a specific recommendation for this population. The risk of dislocation can also vary depending on the severity and type of cognitive impairment, or how much support the person has. They agreed that cognitive impairment is one of many important comorbidities that should be considered when making treatment decisions. It is more important for clinicians to think about comorbidities in the context of functionality rather than whether or not a person has them. The committee also agreed that decisions about whether someone is likely to benefit most from total hip arthroplasty or hemiarthroplasty would normally be made as part of a multidisciplinary team.
The committee discussed the potential long-term benefit of total hip arthroplasty in specific groups of people, in particular younger age groups with fewer or less severe comorbidities. As the evidence did not provide much long-term data, and results were not reported for different age categories, it was agreed that further research should be carried out to inform future recommendations. A recommendation for research on long-term effectiveness of total hip replacement was therefore included to highlight the importance of comparing the effectiveness of total hip arthroplasty with hemiarthroplasty in the long term and determining the effect of each type of arthroplasty on different population subgroups.
The recommendation allows clinicians to use their discretion in deciding who is offered total hip arthroplasty. It should prevent people with mild forms of cognitive impairment being excluded from total hip arthroplasty unnecessarily. As more data becomes available on the long-term benefits of total hip arthroplasty in specific subgroups, there may be an increase in the number of people who are considered for total hip arthroplasty.
The committee discussed the evidence on people who had been given Thompson, Exeter/Unitrax or Exeter Trauma Stem (ETS) components and agreed that health‑related quality of life, mobility, mortality, unplanned return to theatre and adverse-event outcomes were similar across all groups. The committee noted that although there were no cost-effectiveness studies, there was a large amount of variability in femoral component costs across the country for a given type of femoral component and between different types of femoral component.
The Thompson component was cheaper than the ETS or Exeter/Unitrax component, but the committee were aware of future regulatory changes requiring data about implants, meaning that some older designs are unlikely to be used in the future. Without further evidence on other cemented components currently in use, they were unable to recommend one femoral component over another.
To choose the most cost-effective option, the committee agreed it was important for hospitals to consider not only the cost of the component itself, but also the cost of training needs when switching to a new component, alongside any future costs relating to adverse outcomes. There may also be other considerations, in addition to costs. For example, some hospitals may choose to use a femoral component that is suitable for both hemiarthroplasty and total hip arthroplasty to allow consistency and greater efficiency in practice. The committee thought it was important from a training and development perspective that medical teams become familiar with implanting 1 single type of component as standard. They agreed that more research was needed on the effectiveness of different components.
The committee agreed that although the observational evidence was for femoral components not used in the UK, it did emphasise the importance of registry data in exploring longer-term adverse outcomes such as periprosthetic fracture in trauma patients who had undergone hemiarthroplasty. Recording data on hemiarthroplasties for submission to a national registry, such as the National Joint Registry, will help to provide real-world data on the long-term effectiveness and safety of different femoral components in trauma patients.
The committee commented that the 2011 recommendation to use a proven femoral component design (based on Orthopaedic Device Evaluation Panel ratings) came from evidence of people having elective surgery. They queried whether femoral component designs for elective patients who have arthritis were appropriate for trauma patients, given that arthritis often puts people at greater risk of fractures. Therefore, the committee drafted a recommendation for research on femoral component design that would allow data for this fragility fracture population to be captured. Registry data could also be used to evaluate long-term effectiveness in specific subpopulations such as people from different ethnic backgrounds and other groups for which there is currently no evidence.
By recommending 1 femoral component as standard for hemiarthroplasties, surgical teams will become familiar operating with this prosthesis and need less training in different components. Hospitals or trusts will also choose a component that provides the best value for money, but within the context of training requirements, team familiarity and overall costs.
The National Joint Registry already collects data on total hip arthroplasties. Collecting data on hemiarthroplasties in this, or a similar database, may require some extra administrative work. But the real-world data will be valuable in helping future decision makers choose the most clinically and cost-effective femoral component. Having further research on the effectiveness of different femoral components in people from different population groups will also help inform decisions and address health inequalities in this area.