This guide has been written to help patients understand why they need a hip resurfacing or ‘Birmingham hip’, what the resurfacing involves and how they might be expected to recover.
What is a hip resurfacing?
Hip resurfacing is a type of hip replacement which replaces the surfaces of the hip joint. The procedure preserves more bone than a total hip replacement. The head of the femur or ‘ball’ is not removed but is reshaped to allow a metal cap to be cemented on top of it. The surface of the acetabulum “the socket” is also replaced with a metal implant which is wedged directly into the bone. The resurfacing is made of a cobalt chrome which is highly finished to produce very low wear rates.
Who is a candidate for hip resurfacing?
Hip resurfacing is primarily intended for use in patients who need a hip replacement but are rather younger than the normal patient. The indications for hip resurfacing are identical to those of hip replacement. The threshold for requiring surgery does vary somewhat from patient to patient but generally when patients reach the stage of having night pain where their pain and/or hip stiffness significantly restricts their activities and conservative measures such as pain killers, hip block or walking stick are unable to control symptoms adequately.
Hip resurfacing procedure is only available for patients who have adequate bone quality in the neck and ball of the hip joint. For this reason, patients are generally younger with a cut off in men of between sixty to sixty five and in ladies of fifty to fifty five. The decision whether to resurface or replace your hip must be made on an individual basis and also is influenced by your size, your weight, whether or not you smoke and whether there are any other risk factors that might make your bone softer than expected, for example being on steroids.
Patients who are above the age of sixty and have a conventional primary total hip replacement are likely to do extremely well and their prosthesis has a very good chance of lasting their lifetime. For this reason, as patients get a little older the potential advantages of hip resurfacing reduce.
What is the advantage of hip resurfacing?
Hip resurfacing procedure is more conservative with less bone taken away. A revision of a resurfacing hip to a conventional total hip replacement is a relatively straight forward procedure compared to revising a total hip.
Younger more active patients are likely to wear out their conventional hips more rapidly and therefore be at greater risk of requiring revision surgery in the future. By resurfacing a hip, hopefully any future surgery would be more straight forward.
What are the results of hip resurfacing?
Hip resurfacing is a relatively new procedure although some results are now available for patients operated eight to ten years ago. The results of hip resurfacing are similar to those of a total hip replacement in patients of similar ages. The long term reliability of the implant will not be known until it has been in widespread usage for fifteen to twenty years and therefore there is no available evidence as yet to demonstrate that the hip will last longer than a conventional hip.
The resurfacing provides the patient with a large ball and socket which reduces the risk of dislocation, allowing greater range of movement of the hip joint.
What are the disadvantages of hip resurfacing?
Hip resurfacing is not a small procedure. The scar is often a little larger than in a hip replacement. The long term results of hip resurfacing are as yet not known.
Some concerns have been raised about the release of metal ions from the body in metal on metal hip resurfacing, but there is no established evidence to suggest that this has any clinical significance. A very small percentage of patients have been described as having local allergic response to metal release which requires revision surgery.
Other risks associated with resurfacing of the hip are similar to those of a hip replacement, namely, infection 1%; dislocation, leg length discrepancy, venous thrombosis and fracture. The most common cause for failure of resurfacing is a fracture of the femoral neck, hence the importance of appropriate patient selection.
What does the operation involve?
Hip resurfacing as far as the patient is concerned very similar to hip replacement. As our resurfacing patients are generally younger, fitter and more active, however their length of stay is certainly shorter than that for a hip replacement and I have had a handful of patients who have gone home the day after surgery. The average patient is in hospital for three and a half days.
Patients are admitted on the day of surgery, theatre lists often run all day and unfortunately this necessitates a degree of waiting around. Pre-operatively you will be asked to wear a gown, will be seen by the Surgeon and the Anaesthetist and occasion given pre-operative sedation. You will be taken down to theatre where the Anaesthetist will send you to sleep or perform a regional anaesthetic having discussed this with you beforehand. The surgery itself lasts about an hour and a half, after which time you will spend a short time in recovery and then return to the ward.
The day after surgery, you will be got out of bed with the physiotherapist and instructed on how to walk. Some patients need to protect their hip for six weeks with crutches but the vast majority of resurfacing patients are allowed to fully weight bear from day one. Once you are able to walk up and down stairs, and the wound is entirely clean and dry, the Surgeon and physiotherapist are happy, you will be discharged. You will be seen again in six weeks time.
How soon will I recover?
Patients vary enormously, by six weeks most hip resurfacing and replacement patients are walking comfortably and at greater speed and distance than prior to their operation. Many patients will have returned to work by this stage. Your recovery will continue for four to six months after your operation. At six weeks you will be reviewed usually by our unit physiotherapist. Resurfacing patients will be kept under review in the long term and you will be seen yearly, three yearly and then five yearly intervals.
What about work?
Most patients return to work at about the six week stage. More physical jobs may require a longer time off work. Some patients return to work considerably sooner than this.
What about driving?
Patients following resurfacing arthroplasty ought not to drive for six weeks following surgery. It is important that in an emergency you are able to stop the car safely.
What about sports?
Resurfacing patients should avoid jumping upon their hip, certainly for the first three to six months, impact loading such as jogging and running, similarly should be avoided for this time to reduce the risk of a fracture. Most patients are able to return to a high level of activity following their hip surgery. Activities that involve deep bending of your hip such as certain yoga movements are best avoided. After three months, golf, riding, etc should be fine.
What about day to day activities?
Whilst on the ward your physiotherapist will teach you how to get in and out of bed safely, give you advice on dressing, toileting, etc. Do not be frightened to resume normal sexual relations, being careful not to force your hip into an uncomfortable position. Patients are encouraged to wait until they are discharged from the ward.
You will be shown how to get in and out of bed on the ward, advised to sleep on your back for six weeks, etc. Further information on activities to avoid can be seen in the section on hip replacement surgery.