Total hip replacement
Mr Steffen Breusch and Dr Carlo Alonzi discuss what GPs can expect to see after this operation
Mr Steffen Breusch and Dr Carlo Alonzi discuss what GPs can expect to see after this operation
Total hip replacement is one of the most successful, cost-effective surgical operations. It has been practised widely in the UK for the past 25 years and numbers are rising, with about 40,000 procedures performed by the NHS annually. As its popularity increases, the number of post-operative complications outside the hospital setting is also rising.
Upon discharge, both the patient and GP should be given a copy of the discharge summary, which should outline the procedure carried out and any immediate peri-operative complications. Regular medications should be prescribed along with any additional analgesics that are needed. Instructions on the type and duration of thromboprophylaxis should also be included in the discharge letter.
Before discharge, patients will have been assessed by occupational therapists to ensure that their home environment is suitable, and advised by physiotherapists about manoeuvres to avoid and whether or not further physiotherapy is required (it is not normally).
The patients will usually have been informed about postoperative management and precautions during pre-admission, and will have been given an information booklet and contact phone numbers.Exercise levels should be increased gradually in the post-operative period. Generally speaking, if the hip allows, most activities can be performed.
Depending on the orthopaedic unit's preference, different advice may be given to patients locally. Patients may still be advised not to sleep on their side for six weeks or to bear only part of the weight of non-cemented implants for six weeks. But there is no evidence in the literature to support such caution.
To reduce the risk of dislocation, heavy housework should be avoided in the first four to six weeks. Patients are normally able to return to sedentary work at around this time, whereas a more active or manual job may require 12-16 weeks' recuperation. In either case, a gradual return should be recommended.
Driving should not be undertaken less than four to six weeks after surgery, but the determining factor is whether the patient is able to perform an emergency stop without worrying about any pain. Informing the insurance company before driving is always advisable.
It is important for the patient to realise that these are only rough guides and that people will recover at different rates. It may take up to six to 12 months to recover fully from a hip replacement.
As with all surgery, total hip replacement has risks and complications, which must be kept in mind when carrying out a patient review. It is important to differentiate between a normal post-operative finding and a potentially serious complication.Local guidelines and policies should be adhered to as different orthopaedic units will have their own mechanisms for following up patients and dealing with potential complications.
Swelling of the leg in question is a normal post-operative finding and is caused by fluid retention, deep haematoma and impairment of lymphatic drainage. Post-operative swelling tends to be minimal on getting up in the morning and becomes more noticeable as the day progresses.
Patients should be encouraged to perform continuous mechanical prophylaxis against a deep vein thrombosis. It is advisable that patients wear provided compression stockings for around two to six weeks post-operatively and lie down for 30-60 minutes on a daily basis with their legs raised to help reduce this. However, swelling must be differentiated from swelling caused by a DVT. Warning signs of a more sinister cause include:
• associated pain
• swelling that is not improved by elevation
• erythematous changes in the overlying skin
• tenderness (in the calf and sole of foot)
• associated shortness of breath or pleuritic chest pain, which are both indicative of pulmonary embolism.
If a DVT is suspected, the patient should be referred for urgent Doppler ultrasound or venography. Studies using venography have shown that thrombosis can be demonstrated in 30 to 60% of cases at any level, and 10 to 20% of cases proximally if no anticoagulant therapy is given.
Thromboprophylaxis regimens differ between orthopaedic departments and surgeons. Studies have demonstrated that aspirin, as used by some centres, should generally be continued for six weeks post-operatively. Higher-risk patients may be asked to continue low molecular weight heparin (LMWH) injections upon discharge for four to six weeks. Shorter courses of LMWH may produce a rebound effect and are counterproductive.
Most patients are able to self-inject, but it is advisable to assess their ability to comply with the regimen4. Weekly platelet tests are recommended to detect the rare but significant complication of heparin-induced thrombocytopenia. It is normal for the wound to be swollen and tender in a post-operative patient. These symptoms commonly settle after two weeks.
Any erythema – and particularly any wound discharge that lasts longer than a week – should raise the index of suspicion. The diagnosis of an infection can be extremely difficult. A superficial infection may occur, but a deep infection should be suspected until proven otherwise. Deep periprosthetic infection occurs in approximately 0.5 to 2% of cases, and is more likely in patients with other co-morbidities such as chronic renal failure or diabetes6. Signs that suggest an infection include:
• persistent or increasing pain
• spreading erythema
• systemic upset
• wound breakdown or leakage (wound should be dry a week post-op).
Systemic upset may occur. Equally it may be absent, and in some cases joint pain and a persistently elevated C-reactive protein may be the only features. CRP levels should be back to normal after three weeks.If an infection is suspected it is extremely important that antibiotics are not given.
An essential measure in treating an infection of a prosthetic joint successfully is identifying the causative organism. This involves obtaining an aspirate (in the case of the hip, requiring either imaging guidance or obtaining a sample at surgical washout). Antibiotic administration makes culture of the infecting organism difficult or impossible, and should be withheld while a prompt referral to an orthopaedic unit is made.
Pain is to be expected after any major operation, especially once the patient has been discharged, as their activity levels increase and analgesia is curtailed. Wound-related painful swelling usually subsides after two weeks. Deeper muscular pain may take six to 12 weeks to resolve fully.
Worsening pain should always be taken seriously (it may be a sign of infection) and sudden onset of severe pain may be the presentation of a prosthetic dislocation. Dislocation rates vary according to surgical approach and technique, but are in the region of 1 to 3%.
The first six to eight weeks after hip replacement is a high-risk period for dislocation, so patients should be advised to avoid movements that make this event more likely. Simple measures, such as not crossing legs, avoidance of internal rotation and avoidance of flexion to more than 90 degrees should be reinforced.
Patients who had a posterior approach (curved incision towards buttock) are more at risk, and should be advised to maintain external rotation of the feet during sitting down or rising – a simple memory aid is the image of Charlie Chaplin.
In the longer term, pain may mean a prosthesis is loosening. This is an uncommon complication in the first 10 years and the acetabular component is at fault more often than the femoral component. Signs of this may include pain radiating to the groin or thigh/knee, which is generally worse on walking.
The recurrence of pain after three to six weeks is a warning of the possibility of late infection. Suspected infection should lead to urgent referral to the orthopaedic team. Delay or injudicious use of antibiotics before the pathogen is isolated is potentially disastrous.
It is vital the GP liaises with the surgical team and that patients are referred urgently.If there is any concern that a patient is not progressing as planned, or if there is clinical suspicion of a developing problem, most orthopaedic surgeons would prefer that the patient is reviewed sooner rather than later.
This is best done by telephone, directly or by contacting the arthroplasty helpline. Written re-referrals for an acute or serious problem may lead to potentially hazardous delays for the patient. If in doubt, and there are concerns that there may be an infection, the patient should be seen urgently by the orthopaedic team and antibiotics should be withheld.
Mr Steffen Breusch is consultant orthopaedic surgeon at the New Royal Infirmary, Edinburgh
Dr Carlo Alonzi is a senior house officer in orthopaedics and trauma at the New Royal Infirmary, Edinburgh
Competing interests: None declared
• Low-impact activities (walking, cycling)
• High-impact activities (running, jumping)
• Superficial wound infection – cellulitis and infected fat necrosis possibly limited to the area external to the fascia lata. The question is, what lies beneath? The patient needs urgent referral, antibiotics to be withheld or (probably) early surgical debridement with deep tissue samples for culture.
• Inflammation around surgical staples – depending upon age of wound, remove all or every second clip using Steri-strips to reinforce wound.
• Seroma – sterile collection of plasma usually superficial to the fascia lata. If the wound is dry and non-erythematous they should be left to resorb. If persistent leakage is interfering with wound healing they should be referred for drainage and pressure dressing.
• Haematoma – a potent bacterial culture medium that should be drained if fluctuant. It occurs more commonly in warfarinised patients. It can mimic the erythema of deeper infection before it is resorbed.
• Blisters – these are usually caused by stretching the dressings and shearing the epidermal layer. If sterile they should be left intact, but if infected they should be de-roofed and dressed.