This type of replacement is reserved for active young male patients with good quality bone ie: no osteoporosis. There is no advantage for a patient over the age of 50 to have a hip resurfacing.
Modern day resurfacings have been around for the past 14 years. The Birmingham Hip Resurfacing Replacement (Smith & Nephew Inc: www.smith-nephew.com) is the most successful of the Resurfacings on the market and has the longest track record (over 12 years) We have learned a great deal about resurfacings and the literature (including the Australian Joint Registry www.dmac.adelaide.edu.au/aoanjrr/) has outlined the best patients that are suited for this procedure.
Important facts to know about hip resurfacing
Hip resurfacing patients take longer to recover than conventional total hip surgery patients. The reason for this is that in order to preserve the femoral head for resurfacing, more muscle and ligaments need to be released internally to allow the socket to be prepared. Patients are also advised to partial weight bear for 4 weeks post operatively to allow the bone to adapt to the new implant and not fracture. Conventional hip replacement patients are allowed to full weight bear immediately.
Hip Range of Motion in Resurfacing replacements is less than conventional total hip replacements using the same size ball and socket. The reason for this is that the resurfacing sits on the patient’s femoral head and neck and as such in maximal motion the femoral neck may impinge on bone preventing maximum movement compared to a ball that sits on a stemmed hip because the stemmed hip has a narrow neck allowing more impingement free motion.
A good functioning hip resurfacing is very durable and whilst it is not recommended, there have been many reports of patients running and doing triathlons with resurfacings.
All hip replacements, resurfacing or conventional, allow the patient to partake in sporting activities including:
- Backyard running with the kids
As a general rule orthopaedic surgeons do not recommend high contact sports with any type of replacement (resurfacing or conventional) including rugby, competition soccer, competition basketball etc.
What's the advantage of having resurfacing?
Resurfacings preserve the femoral shaft and there are reports that some patients feel that the resurfaced hip “feels more natural”
It allows the possibility of a future revision to be done without to much difficulty, however, it is likely that a well done standard total hip replacement with a modern day bearing will not need revising anyhow.
The biggest issue with metal on metal resurfacings is accuracy in surgical technique. This fact has only recently come to our attention as it was thought that metal on metal implants are as “forgiving” as metal on plastic implants. Recent literature has shown that the metal on metal implants (and ceramic on ceramic bearings) are very susceptible to mal-alignment and if this occurs then these implants may fail.
Cemented or Uncemented prosthesis:
There is no difference in the revision rates of either a cemented or uncemented femoral component (the hip stem that sits on the thigh bone). A well implanted cemented stem works just as well as a well implanted uncemented stem. As outlined above the key to longevity is in the bearing and NOT whether the stem is cemented or uncemented. A surgeon will choose what stem fits best into your bone quality. In general softer osteoporotic bone with thin cortices do better when cement is used to fixate the implant.
Most acetabular components (sockets) are uncemented and the bone will grow into the component. The lining is then placed in the metal shell and this lining is either plastic, ceramic or metal. Occasionally the bone is so soft that a plastic liner is cemented onto the bone instead of using and uncemented shell.
My approach and recommendations to patients requiring a hip replacement:
This is a guide only and each patient’s individual needs are taken into account before a final implant decision is made. An individual assesement is made as to what surgical approach is best for you.
Patients over the age of 75 usually have an uncemented stem (if bone quality good) or cemented stem (if bone quality poor) with an uncemented socket and polyethelene (plastic) liner. A metal head is used. This hip should last a lifetime
Patients between 65-75 usually have an uncemented stem and socket with either a ceramic on ceramic liner or ceramic on polyethelene liner. This hip should last a lifetime
Males under the age of 55 who are active and have excellent bone quality are candidates for a resurfacing, however we discuss the pros and cons of resurfacing vs total hip replacement with a ceramic bearing according to the patients individual circumstances.
Females under age 65 usually have an uncemented stem and socket with a ceramic on ceramic bearing
Males between 55-75 usually have an uncemented stem and socket with the bearing appropriate for their age.
Before surgery you will need to attend a pre-admission clinic at the hospital where you will meet a clinical nurse who will go over the basic admission process and post operative course. In addition there are routine pre-operative blood tests and an ECG that are performed. Occasionally a chest X-ray is needed.
If any significant abnormality is detected in your pre-operative visit, the appropriate action/referral will occur to investigate and treat any issue needing attention.
If you see a cardiologist routinely and are on a regular blood thinner, please advise your cardiologist you are having a joint replacement and that you need to stop blood thinners such as warfarin, plavix/clopidigrol and aspirin. I am happy to perform the replacement under low dose aspirin (100mg) if your cardiologist insists.
The final word
I hope I have enlightened you on the basic facts about hip replacement surgery. I would summarize as follows:
- Choose a surgeon who is well experienced in Hip Replacement Surgery
- Be guided by the information presented above as to the types of hip replacements available, bearing options and operative approaches.
- Do not be fooled by all of the advertising and marketing hype surrounding institutions. Take your time to learn about your surgeon before making your decision.