Over the last ten years, hip resurfacing has become increasing popular, and many patients have received excellent results from hip resurfacing. Although an excellent procedure, not all patients with hip arthritis are suitable for hip resurfacing. As with any operation, it is important to be accurately informed about the procedure and the alternatives available.
Hip resurfacing is an artificial joint replacement used for the treatment of severe arthritis.
Many patients with early hip arthritis are able to adequately control their arthritis symptoms without requiring surgery (see 'Non-Surgical Treatments'). Some patients may benefit from hip arthroscopy (key-hole surgery) or other joint preserving surgical procedures. For patients who require artificial joint replacement, the alternatives are hip resurfacing or Total Hip Replacement (THR). I will recommend a particular treatment based on your requirements.
Yes. Hip resurfacing provides reliably good results in appropriate patients.
In Total Hip Replacement (THR), the ball and socket of the hip joint which have become worn as a result of arthritis are replaced. The femoral head is removed, and a stemmed component is placed into the central part of the upper thigh bone (see Figure 1). A hip resurfacing is similar, however instead of removing the femoral head completely, only the damaged cartilage and a small amount of bone is removed, and a metal cap is placed on top (see Figure 2).
In modern orthopaedic practice, the main advantage of a hip resurfacing compared to a total hip replacement is preservation of bone at the top of the thigh bone (see Figure 2). Should the further surgery be required in the future for loosening of the artificial joint replacement, preserving this bone makes the revision surgery less complex, shortening the recovery time and improving the durability of the second operation. Preserving bone is therefore most important in younger patients with higher activity demands, who may potentially outlive an artificial joint replacement of any design. Hip resurfacings utilise impact and wear resistant bearing surfaces, suitable for higher grade activity demands. The incidence of dislocation after hip resurfacing is reduced in comparison to total hip replacement.
 |
 |
Figure 1 |
Figure 2Hip Resurfacing |
Hip resurfacings can fail in ways which are not seen with a total hip replacement. In particular, as the bone at the top of the thigh is retained in a resurfacing, weakening of this bone can result in a fracture (bone break) or collapse. This complication occurs in approximately 2% of resurfacings. Fractures usually require further surgery, and often involve revising the resurfacing to a total hip replacement. In addition to the risk of fracture, resurfacings are only available with Metal-on-Metal (MoM) bearing surfaces. While MoM bearings have a very low wear rate and are impact resistant, there are theoretical risks associated with this type of artificial joint replacement. Should a MoM bearing be recommended then the advantages and disadvantages of this implant will be discussed with you in detail.
Generally, the ideal candidate for hip resurfacing is a male patient less than 60 years of age with high activity demands and severe osteoarthritis of the hip.
Patients over the age of 65, particularly females, are generally better managed with a total hip replacement. Patients with arthritis due to hip dysplasia (shallow hip socket) or avascular necrosis are at higher risk of implant failure if treated with hip resurfacing.
Yes. While your hip may not be ideally suited to resurfacing, there are alternatives available which are similar to hip resurfacing which may be considered. These may include a 'microplasty' total hip replacement (short femoral stem) or a 'Birmingham Mid-Head Resection' (BMHR) arthroplasty. 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 any given option prior to surgery.
| Table 1: Comparison of Hip Resurfacing v Total Hip Replacement. | ||
|
|
Hip Resurfacing | Total Hip Replacement (THR) |
|
Indication |
Severe arthritis. Pain not controlled by other methods | Severe arthritis. Pain not controlled by other methods. |
|
Design features |
Ball and socket both replaced. Only damaged cartilage and surface bone removed from femur (ball). | Ball and socket both replaced. Stemmed femoral component (150mm rod) placed into hollow centre of thigh bone (femur). |
| Bearing surface | Metal on Metal (MoM) only. | Any bearing surface (including MoM bearings identical to a resurfacing) can be selected |
| Advantages | Future revision of femoral component simplified. | Lower early complication rate. |
| Disadvantages | Early fracture requiring revision 2%. Risks of MoM bearing surface. | Removes more bone from femur. Revision of femoral component can be difficult. |
| Durability | Durability >15 years uncertain, but unlikely to be better than total hip replacement. | Long term results (>20 years) well documented. |
| Pain relief | Excellent pain relief is reliably predicted. | Excellent pain relief is reliably predicted. |
| Leg Length | Limited ability to correct significant inequality in leg length | Able to correct significant variations in leg length |
| Table 2: Patient suitability for hip resurfacing | ||
|
Good Candidate |
Borderline Candidate |
Poor Candidate |
|
Age <60 years Male High activity level Osteoarthritis |
Female Metal allergy Avascular necrosis Hip dysplasia Future pregnancy |
Age >65 years Kidney disease Osteoporosis |
|
|
Table 3: Common misunderstandings about hip resurfacing | |
| Resurfacing is an appropriate option for 'early intervention' | No. Artificial hip joint replacement is a major procedure with potential risks. Like total hip replacement, the decision to use an artificial joint replacement should only be made on the basis of ongoing symptoms which are not adequately relieved by other methods. | |
| Resurfacing has a unique Metal-on-Metal (MoM) bearing surface | No. The bearing surface is not unique to resurfacing. An identical bearing can be chosen for THR. See information sheet 'Bearing surfaces in hip joint replacement'. | |
| Resurfacing lasts longer than THR | No. Although the results after resurfacing are promising, the Australian National Joint Registry shows that resurfacing has a slightly higher early failure rate compared to THR. | |
| Resurfacing has a lower dislocation rate than THR | Depends. Dislocation is an uncommon complication after artificial joint replacement of any design. Many factors influence the risk of dislocation, and design of the joint replacement is only one of these factors. Joint replacements such as resurfacings which use a larger diameter ball and socket generally do have a lower dislocation rate, however modern THR designs may also use an identical diameter ball and socket. | |
| Resurfacing allows patients to be more active compared to THR | Depends. Resurfacing implants use metal on metal bearing surfaces which are both wear and impact resistant. Some hip replacement designs may also use this bearing surface. Both resurfacing and THA provide reliably good pain relief and improvement in function. | |
| Young, active patients who require an artificial hip joint should have a resurfacing | Depends. Hip resurfacing may be a good option, however modern THR should also be considered. I will recommend a particular treatment based on your individual requirements. | |
This information has been written by Dr Patrick Weinrauch for the purposes of patient education. The details provided are of general nature only and do not substitute for professional recommendations based an individual clinical assessment.
