Fast-Track Total Hip Replacement
Fast-track total hip replacement is a term that describes a process of rapid rehabilitation after hip replacement surgery. The principle is to discharge a patient after surgery in the same physical condition as they would have demonstrated had they received a more traditional approach and stayed in hospital for seven to ten days. Fast-track hip replacement surgery is not open to every patient but is based upon three concepts:
- Patients generally prefer to be at home than in hospital.
- Mobility in the early stages after hip replacement surgery reduces the chance of complications, deep vein thrombosis (DVT) in particular.
- Rapid rehabilitation improves a patient's confidence in their replaced joint.
The fast-track system involves a number of modifications to the hip replacement process. These involve pre-operative assessment, modified surgical techniques, modified anaesthetic techniques and modified rehabilitation under physiotherapy guidance.
Pre-operative Assessment
Pre-operative assessment will normally take place between ten days and three weeks before surgery. It is critical to the success of the fast-track system that planning for discharge is made before a patient is admitted for their operation. There is little point in being in hospital only to find that the procedure has gone well but that the facilities do not exist at home for the patient to be discharged. The object of pre-operative assessment is therefore not only to ensure that a patient is fit for surgery but also to be certain that their home environment is prepared and ready for discharge. For example, are any special items of equipment required? If so, have they been ordered? Who is going to do the cooking? Is there enough food in the house? Pre-operative assessment also gives a patient the opportunity to ask further questions and, if necessary, to see an anaesthetist. From a surgical viewpoint, the medical staff need to know whether a patient is sufficiently fit to cope with a major operation and whether any associated conditions might delay discharge. For example, sometimes diabetes requires a slightly extended stay in hospital or, perhaps, a patient has a previous history of DVT and might therefore need to be in hospital a little longer than normal.
Surgical Technique
In order to help a patient to mobilise rapidly after surgery, the surgical incisions are kept as small as possible. This is the so-called minimal incision technique of hip replacement. Clearly, the less soft tissue that is involved in an operation, the better the rehabilitation potential for a patient. Special instruments, which have been specifically designed for small incisions, are used for these procedures. As a rough guide, incisions will be 10cms or less in length, although safety is never compromised, so if the surgeon needs to make an incision longer than this in order to gain access to a tricky part of the hip, he will do so. A longer incision does not necessarily mean that a patient will take longer to rehabilitate. Patients who are significantly overweight should be aware that it is sometimes impossible to undertake minimal incision hip replacement for them.
Anaesthetic Technique
If a general anaesthetic can be kept fairly light during an operation, a patient will recover more rapidly and be more awake, with less nausea straight after the procedure. This will allow them to mobilise more rapidly, often within a few hours of the operation. In order to keep an anaesthetic light, local anaesthetic techniques can be used either as a substitute for, or a supplement to, general anaesthesia. There is a variety of such techniques but the broad principle is that a local anaesthetic nerve block can be used which will eliminate a patient's pain but not hinder them from walking. The lumbar plexus block is very popular in this respect. This is a challenging anaesthetic technique and is not always applicable to every patient. Nevertheless, the principle is to allow a patient to wake up rapidly after surgery and, only a matter of hours later, to encourage them to walk fully weight bearing with little or no pain at all. Largely the lumbar plexus block provides the post-operative pain relief. This allows the medical staff to avoid the use of morphine-based drugs, which are good at relieving pain but also sedate a patient. A sedated patient tends not to mobilise very quickly.
Principles of Rehabilitation
To take advantage of the small surgical incision and special anaesthetic technique, it is important that a patient mobilises as soon after their operation as possible. Intensive physiotherapy is therefore provided with a patient gradually progressing through a series of stages, of increasing complexity, until they are ready for discharge. Generally, a patient is ready for discharge when they are able to get in and out of their bed without assistance and to ascend and descend stairs, supported by crutches, but again without assistance. For many patients this stage is reached within 24 hours of hip replacement surgery although clearly not every patient will mobilise so quickly. The time of discharge is determined not by the number of days after the procedure but by the physical abilities of the patient. Everyone goes at their own pace and the medical staff recognise this. However, as soon as a patient is sufficiently confident and capable they are discharged. The aim is for a patient to be as mobile after 24 hours as they would have been after 5 days using a more traditional hip replacement regimen.
The Future
Minimal incision surgery has obviously captured the imagination of patients, managers and surgeons. However, it must be realised that the size of the incision is only one part of the overall procedure. An increasing number of surgeons would say that incision size is irrelevant. Anaesthesia and physiotherapy are key aspects to modern hip replacement surgery. Hence the term ‘fast-track’, attempting to describe the holistic approach to this common operation, an approach that is critical to the early discharge of a happy patient to their familiar, home surroundings.
Typical Fast-Track Sequence
D-14: Pre-operative Assessment (interview, examination, tests, further questions answered, discharge planning)
D0: 0600hrs: admission to hospital
0700hrs: surgery
0900hrs: return to ward
1300hrs: drain removed, X-ray taken, blood count checked
1400hrs: rehabilitation starts
D+1: Rehabilitation continues. Fast mobilisers will be discharged by the afternoon, supported by two crutches.
It must be stressed that the decision to discharge a patient is based entirely on how they are mobilising. No patient will be discharged until they are ready and safe to do so. However, the majority of patients will have been discharged by the third post-operative day (D+3).