HIP RESURFACING
SURGERY
The hip is a ball and socket joint. The BIRMINGHAM HIP Resurfacing (BHR) System is a conservative approach to replacing this joint, in which the moving surfaces (bearing surfaces) are made of metal. The BHR replaces the surface of the femoral head (ball) and acetabulum (socket), but preserves the bone within the rest of the femur including the neck.
Benefits of Hip Resurfacing
The BHR is particularly suited to active male patients requiring hip replacement. Hip resurfacing tends to be a better match to the size of the patient’s own hip. This reduces the risk of dislocation and some patients report the hip feels more ‘normal’. Resurfacing patients often report a quicker post-operative recovery in the short term and patients with a hip resurfacing are more likely to go back to sporting activities including competitive sports.
Features of the BHR include:
Less bone resection than conventional total hip replacement
Excellent, long-term clinical outcomes
Less risk of dislocation compared to total hip replacement in active patients
The results of the BHR are well documented through independent clinical studies and national joint registries. On average, more than 90% of hip resurfacings in men are still working well after ten years.
Birmingham Hip Resurfacing can only be used in male patients with a hip measuring greater than 50mm, this is because the complication rate including failure is higher amongst females and patients with smaller hips. Active males with osteoarthritis of the hip are most suitable for this treatment and seem to have the best results, with failure rates around 0.5-2% at 10 years.
The approach to the hip varies, but most surgeons tend to use a so called “posterior approach” (through the side of the hip and buttock area). Hip resurfacing procedures can cause a scar that may be slightly longer than a standard hip replacement as it is necessary to work around an intact femoral neck. The acetabulum (cup) is prepared as for a hip replacement and a metal shell inserted with a friction fit. The worn surface of the head is then carefully reshaped, and a metal cap applied with cement.
After surgery, you will start walking with the help of two crutches for up to 6 weeks to allow soft tissue healing and getting used to your new hip. You will be discharged home after passing the physiotherapist assessment and when it is safe to go home. Your hip wound will be checked at approximately 2 weeks and if necessary any stiches or clips removed. We tend to see you routinely in clinic at 6 weeks, unless there is any problem, in which case, you should call the ward which looked after you. You can also contact the consultant secretary if you cannot get through to the ward staff.
Risks and Complications
The vast majority of patients make a rapid recovery after hip resurfacing and experience no serious problems. However it is important you understand that a hip resurfacing is a major operation and that complications can occur.
Venous Thromboembolism (VTE)
Blood clots in the leg veins (deep vein thrombosis) and blood clots in the lungs (pulmonary embolus) are a risk associated with hip resurfacing surgery. The simplest way of reducing this risk is early mobilisation (exercises and walking). Whilst in hospital you will also be prescribed blood thinning treatment, usually in the form of injections, to reduce the risk of clot formation. If you are already receiving anti-coagulant therapy will be assessed and advised accordingly.
Infection
Where possible, the wound dressing will stay on until the removal of your clips or stitches. After discharge, if you have any concerns about your wound, please call the ward or the secretaries.
A deep infection of the joint most often starts when bacteria gain access to the tissues at the time of surgery and great lengths are taken in theatre to reduce the risks of this happening. Operations are carried out in an ultra- clean air theatre and sterile clothing is worn by the surgical team. You will be given preventative antibiotics at the time of surgery. Despite all the precautions taken, infections can still occur. An early deep infection may rarely occur and this would require a further operation to clean the hip resurfacing. Occasionally it would be necessary to take out the hip resurfacing to resolve the infection. It is likely you would require a long course of antibiotics.
An infection can occur at any stage in the life of a hip resurfacing. The reason for this is that any infection in the body can circulate in the blood and settle on the surface of the new hip joint. Once there it forms its own environment, or ‘bio-film’, which makes it difficult to treat with antibiotics alone. Although the symptoms of infection can often be suppressed with antibiotics the only way to eliminate this deep infection is to remove the artificial implant.
Remember infection is a serious complication. If you develop any new redness around the wound or if the wound leaks after leaving hospital, it is important that you let us know.
Urinary problems
Some patients, particularly those who may have previously experienced difficulty passing water, may sometimes need a catheter to be inserted into the bladder prior to or after the operation. Except in certain circumstances, this should be removed the morning after surgery or prior to discharge.
Bleeding and Bruising
Bleeding occurs during and after surgery. However, this is usually relatively limited and controlled and simply causes local bruising.
It is common to see bruising around the hip in the days after surgery and, occasionally, this bruising will extend down the leg, sometimes into the foot.
Blood transfusion following hip resurfacing is rarely needed. If your blood count is very low or if you are showing symptoms of anaemia (low blood count), we may recommend a blood transfusion.
Very rarely if there is a lot of scarring around the hip a major blood vessel can be injured leading to a risk of life or limb threatining bleeding.
Nerve damage
The skin over the outer side of the hip wound can feel numb for up to 12 months until the nerve fibres recover - this is normal.
Very occasionally one of the main nerves that run past the hip can be damaged during the operation. This can cause a foot-drop or paralysis of other muscle groups in the leg. Although the nerve often recovers over a period of months the paralysis can persist.
Leg swelling
Leg swelling is a normal response to the operation and will settle week by week as your body absorbs the bruising. Exercises and walking can help reduce the swelling but standing unnecessarily should be avoided. If the swelling increases or if it is accompanied by tenderness in the calf or groin, a temperature or breathing problems you should ask your GP for advice.
Other general medical problems
Complications such as heart attack, stroke or death can occur after hip resurfacing as with other forms of major surgery. These complications are rare and the anaesthetist will not allow the operation to proceed if it is felt that the risks are significantly higher than normal. In this circumstance, it may be that you are sent for further tests or treatment prior to surgery being performed.
Cement syndrome
This is rare and is caused by the cement used to fix your hip resurfacing causing problems with your circulation. Although this can be serious it is most commonly treated with extra oxygen therapy.
Metallosis
The Birmingham Hip Resurfacing procedure has been tarnished by copy metal on metal resurfacing implants which through various design changes reduced the success of the procedure. As a result the government issued guidance that means all patients with metal on metal implants are kept under long term surveillance (https://www.gov.uk/drug-device-alerts/all-metal-on-metal-mom-hip-replacements-updated-advice-for-follow-up-of-patients). Birmingham Hip Resurfacing has retained its original design and remains one of the hip resurfacing implants of choice with some of the best results. However, a small proportion of patients can develop so called “metallosis”. In metallosis small metal particles rub off from the implant and can lead to inflammation, allergy and damage to the local soft tissues and bone. This can cause ongoing pain and often steadily worsens. The treatment is to replace the metal bearing with an alternative implant typically a conventional hip replacement.
Dislocation
Dislocation occurs in a very small number of patients undergoing hip resurfacing. This may require a manipulation under anaesthetic to restore the alignment of the joint. If it kept happening then it may require redo surgery.
Fractures
Very rarely, fractures (breaks) of the bone can occur during the course of surgery. These are almost always identified during surgery or on the check x-ray after the surgery. Occasionally, this requires further surgery or the surgeon may simply slow down your activities for several weeks to allow the fracture to heal.
Avascular necrosis
Sometimes the blood supply to the hip is damaged and the bone around the resurfacing then fails. This is rare but would usually require redo surgery to a conventional hip replacement if it occurred.
Leg length
The surgeon will try to ensure that your legs are of equal length but cannot guarantee this. Small differences may not cause any problems but if the difference is significant it can be corrected by using a shoe insert or heel-raise on the appropriate side.
Aching in the joint and stiffness
Most are delighted with their hip resurfacing. Some people describe aching or stiffness in the joint or have a limp which does not improve. This is rare and will be investigated thoroughly by the team looking after you.
Ectopic bone or heterotopic ossification (extra bone formation) The body may form new bone in the tissues around the hip in response to the trauma of the operation. This tends to occur only in the immediate recovery phase and may lead to long-term stiffness of the joint.
Tendinopathy
Some patients develop tendinopathy after surgery. This can manifest as pain either over the side of the hip (gluteus medius tendon) or in the groin (psoas tendon). The pain can often be helped with physiotherapy and exercises but in some cases can be persistent for months or even years.