What is Hip Resurfacing?
Hip Resurfacing an alternative to conventional Total Hip Replacement used for the management of established osteoarthritis. Hip Resurfacing utilizes a bone preserving prosthetic implant with exceptional wear, impact, and dislocation resistance and is commonly recommended in younger and higher activity demand people who are experiencing problematic symptoms that are not adequately controlled by non-surgical therapies.
What are the Differences between Hip Resurfacing and Conventional Total Hip Replacement?
In conventional Total Hip Replacement procedures, the femoral head (ball of the hip) is removed and a stem implant (rod) is placed into the central part of the upper thigh bone. Onto the hip replacement stem, a ball component is placed that is free to move within the prosthetic socket (acetabulum).
In Hip Resurfacing, the femoral head bone is retained and no stem implanted into the upper thigh is necessary. The Hip Resurfacing procedure involves removing the damaged arthritic joint cartilage and re-lining the joint surfaces with prosthetic bearing surfaces (hence the name ‘resurfacing’).
What are the Advantages of Hip Resurfacing?
In modern orthopaedic practice, the main advantage of a Hip Resurfacing compared to conventional Total Hip Replacement is preservation of bone at the top of the thigh bone. Should further surgery be required in the future, preserving this bone makes the subsequent revision procedure less complex, thereby shortening the recovery time and potentially improving the durability of the second operation.
Preserving bone is therefore most important in younger people with higher activity demands, who may potentially out live an artificial joint of any design.
Metal Hip Resurfacing uses impact and wear resistant bearing surfaces that are more suitable for higher grade activity demands including running and impact sports. The incidence of dislocation is much lower for Hip Resurfacing in comparison to conventional Total Hip Replacement.
What are the Disdvantages of Hip Resurfacing?
Not all people are suitable for Hip Resurfacing. People who are less suitable for metal hip resurfacing devices include those with a severe hip deformity or reduced bone strength due to cysts or osteoporosis. Importantly, there is a minimum size requirement for metal hip resurfacing procedures – hip resurfacing is unsuitable for people where the femoral head is of smaller size (this applies to many women).
Traditionally, Hip Resurfacing uses Metal-on-Metal (MoM) bearing surfaces. While MoM bearings have a very low wear rate and are impact resistant, a small number of people may develop allergic-type reactions with this type of bearing. The incidence of this reaction in modern Hip Resurfacing is approximately 0.5% in appropriately selected candidates. Should Hip Resurfacing be recommended then the merits of this implant in comparison to alternative prosthetic designs will be discussed with you in detail.
Unfortunately, the adverse publicity surrounding complications associated with one poorly designed Hip Resurfacing implant has seen a great reduction in the use of all Hip Resurfacing implants in Australia. In suitably selected patients operated on by suitably trained surgeons, the results are excellent.
Associate Professor Harvie underwent Orthopaedic Training on the prestigious Oxford Surgical Training Program and was a former University of Oxford Girdlestone Memorial Scholar in Orthopaedic Surgery. In Bristol, the UK in 2006 he gave a presentation at a meeting solely related to the Biological Implications of Metal-on-Metal Articulations entitled ‘Pseudo-tumour following resurfacing arthroplasty – A case series.’ This was the first occasion in the World that the allergic-type reactions to MoM Hip Resurfacings were announced. He has published several research papers on this subject.
Are Metal on Metal bearing surfaces toxic?
While it is possible to develop local allergic reactions to the cobalt-chromium alloy bearing surfaces used in Hip Resurfacing, the incidence of these reactions with the Birmingham Hip Resurfacing (BHR) and the Adept Resurfacing implants is low in appropriately selected patients (approximately 0.5- 1.0%). Other ‘copy’ devices (in particular metal-metal bearing conventional Total Hip Replacements) have unfortunately demonstrated unacceptably high failure rates, necessitating their withdrawal from use in many countries.
The Birmingham Hip Resurfacing was introduced for clinical use in 1997 with now over 125 000 implantations World-wide and demonstrating excellent 15 year survivorship data.
Do alternative bearing surfaces exist for Hip Resurfacing?
More recently, a ceramic on ceramic Hip resurfacing has been developed and become available for the management of advanced hip osteoarthritis. These implants have only been in clinical use in well controlled research centres since 2018 therefore the long term clinical results are not yet known and these implants are not on general release.
Until longer term performance data is available I recommend MoM Hip Resurfacing in appropriately selected patients.
Who is Suitable for Hip Resurfacing?
Traditionally, the ideal candidate for MoM Hip Resurfacing is a larger framed male less than 65 years of age with severe osteoarthritis of the hip. Increasing evidence does however support the use of Hip Resurfacing in people older than 65, provided they meet all other requirements for the procedure.
Who is Unsuitable for Hip Resurfacing?
People with arthritis due to underlying hip dysplasia (shallow hip socket) are at higher risk of implant failure if treated with Hip Resurfacing. Generally people with significant hip dysplasia are not suitable for hip resurfacing.
Size of the femoral head bone is arguably one of the most important factors determining outcomes after Hip Resurfacing. As smaller implant sizes (less than 48mm for the femoral component) are associated with increased failure rates.
Accordingly, many females with hip osteoarthritis do not meet the skeletal size requirements for resurfacing.
Does resurfacing last longer than THR?
The results documented to date show similar implant survivorship rates between Hip Resurfacing and conventional Total Hip Replacement in appropriately selected patients.
Although the demonstrated 15 year results of Hip Resurfacing are exceptional in the Australian National Joint Registry and other studies, the longer term (>20 year) results have not yet been described (Birmingham Hip Resurfacing was first released for clinical use in 1997).
What surgical approach is used?
Whilst it is possibly to undertake Hip Resurfacing via a Direct Anterior Approach I feel this technique is unnecessarily challenging and conveys no superior benefit. I therefore recommend Hip Resurfacing is implanted using a Posterior Approach to the hip joint.
Do you peform Hip Resurfacing?
Yes. Recommendations for treatment with a particular prosthesis or procedure are made taking into account a number of factors.
I will discuss with you in detail the relative merits of the suitable options after your evaluation in clinic.
Hip Resurfacing provides reliably good results in appropriately selected people.
What are the Risks and Complications?
As with any major surgery, there are potential risks involved. The decision to proceed with the surgery is made because the advantages of surgery outweigh the potential disadvantages. It is important that you are informed of these risks before the surgery takes place. Complications can be medical (general) or local complications specific to the Knee. Medical complications include those of the anesthetic and your general well being. Almost any medical condition can occur so this list is not complete.
Complications include:
- Allergic reactions to medications
- Blood loss requiring transfusion with its low risk of disease transmission
- Heart attacks, strokes, kidney failure, pneumonia, bladder infections
- Complications from nerve blocks such as infection or nerve damage
- Serious medical problems can lead to ongoing health concerns, prolonged hospitalization or rarely death
Infection can occur with any operation. In the hip this can be superficial or deep. Infection rates are approximately 1%. If it occurs, it can be treated with antibiotics but may require further surgery. Very rarely your hip may need to be removed to eradicate infection.
These can form in the calf muscles and can travel to the lung (Pulmonary embolism). These can occasionally be serious and even life threatening. If you get calf pain or shortness of breath at any stage, you should notify your surgeon.
Ideally, your knee should bend beyond 115 degrees but on occasion, may not bend as well as expected. Sometimes manipulations are required. This means going to the operating room where the knee is bent for you while under anesthetic.
The plastic liner eventually wears out over time, usually over 10 to 15 years, and may need to be changed. Alternatively the remainder of your own knee may wear out requiring revision to a Total Knee Replacement.
Fractures or breaks can occur during surgery or afterwards if you fall. To repair these, you may require surgery.
The operation will always cut some skin nerves, so you will inevitably have some numbness around the wound. This does not affect the function of your joint. You can also get some aching around the scar. Vitamin E cream and massaging can help reduce this. Occasionally, you can get reactions to the sutures or a wound breakdown that may require antibiotics or rarely, further surgery.
The knee may look different than it was because it is put into the correct alignment to allow proper function.
Your leg will be restored to it’s original length as the deformity caused by wearing of the knee has been corrected.
There are a number of ligaments surrounding the knee. These ligaments can be torn during surgery or break or stretch out any time afterwards. Surgery may be required to correct this problem. This problem is minimised with Robotic Assistance.
Rarely these can be damaged at the time of surgery. If recognized they are repaired but a second operation may be required. Nerve damage can cause a loss of feeling or movement below the knee and can be permanent.
Discuss your concerns thoroughly with your Orthopaedic Surgeon prior to surgery.
Summary
Surgery is not a pleasant prospect for anyone, but for some people with arthritis, it could mean the difference between leading a normal life or putting up with a debilitating condition. Surgery can be regarded as part of your treatment plan it may help to restore function to your damaged joints as well as relieve pain. Surgery is only offered once non-operative treatment has failed. It is an important decision to make and ultimately it is an informed decision between you, your surgeon, family and GP. Although most people are extremely happy with their new knee, complications can occur and you must be aware of these prior to making a decision. If you are undecided, it is best to wait until you are sure this is the procedure for you.