Orthopaedic Surgeon
specialising in Hip and Knee
Replacements

TOTAL HIP REPLACEMENT (THR)

THR involves replacing the worn parts of the hip joint. The normal hip is a ball-and-socket joint. Both the socket and the ball parts of the joint are replaced during a total hip replacement. There are three aspects to the new joint which are of importance;

·       FIXATION

o   The new implants are fixed into bone by one of two means. The first method involves the use of bone cement which secures the implants to the bone by acting like a combination of glue and grout. The second way is relatively newer and relies on the surface finish and lining of the implants. It does not require cement. The properties of the implant mean that your own bone grows onto the implant thus securing it in place. Both methods have long term successful data supporting their use.

·       SIZE OF THE JOINT

o   The larger the diameter of the ball-and-socket joint better the range of movement. The size that can be used is limited by the size of the original joint as well as the materials used.

·       MATERIALS MAKING UP THE JOINT

o   The combination of materials making up the joint can be broadly divided into two. So called hard-on-soft bearings are made of a metal or ceramic ball and plastic socket part. Most long term studies are based on this combination and show success rates in excess of 90% at 20 years.

Your suitability for a THR will be determined as a joint decision with your surgeon. This will depend on your symptoms, findings on examination and expectations from treatment. An X-ray examination is an essential part of this decision process.

The results of total hip replacement are generally excellent. People who undergo the procedure have significant pain relief and restoration of physical function. Patients are usually admitted to hospital on the day of surgery and on average stay for2 days in hospital. All necessary pre-operative investigations (blood tests, ECG and x-rays) are carried out in the weeks preceding the procedure in a special PRE-ASSESSMENT clinic by specialist nurses.

The Anaesthetic

Total hip replacement is carried out under anaesthesia. This may involve either a general anaesthetic (where you are asleep) or a regional anaesthetic (injection into the back- epidural or spinal). You will have a chance to discuss your suitability to one of these methods and choice with the anaesthetist on the day of surgery.

Most patients find regional anaesthesia a scary prospect before, but are very satisfied with it after the event.

The Operation

The goal of hip replacement surgery is to relieve pain in order to allow an active life. This relies on the correct placement of the implants in the pelvis and the femur. The position of the implants also has a major influence on how long the implants would be expected to last.

During the operation exposure and access to the bones is very important for correct positioning of the implant. One of the ways in which this is done is by the “posterior approach”, where the hip joint is reached through the back. This allows the surgeon to have excellent access to all parts of the hip joint and to have a full view of the bones. The posterior approach allows the surgery to be carried out with very little damage to the soft tissues surrounding the hip. It also lets the surgeon carry out the operation through a small incision.

The bones making up the hip joint are then shaped, using reamers and broaches to accept the implants. These are then either cemented or impacted into the bones. The small muscles cut are then repaired using sutures. Throughout this process the stability of the joint and the leg length are repeatedly checked.

The wound is closed using sutures under the surface of the skin. There will not be any stitches to take out after the wound has healed.

Early Post-Operative Period

Following surgery, you will return to the ward. Most people are able to eat and drink straight away. You will be able to stand and take a few steps once the anaesthetic has worn out.

On the day after your surgery you will be seen by the physiotherapists. They will show you how to walk safely using supports and the exercises you have to do when you are sitting or lying down. You will also have an X-Ray examination of your hip.

Over the next few days you will be progressively more mobile and will be able to go home whenever you are able to walk up and down stairs. This usually takes 2 days.

After Discharge

You do not routinely need physiotherapy after discharge. However, if it is felt that you may benefit from this an appointment will be made before you go home. You will be given a sheet of instructions to follow at home. It is important that you continue exercising at home as this will ensure the best result from your operation.

It takes about 6 weeks for you to notice a big improvement in your hip. This is when we remove all restrictions with regards your activities. You should be able to drive after 4-6 weeks. After about 3 months you will be able to do most things. Overall it takes 1 year for you to reach maximum recovery.

Follow-up

Your first routine follow-up appointment will be at 3 months. This is to ensure that your wound has healed up and that you are progressing with your mobilisation.

You will have a second appointment at 1 year following surgery. You will have an x-ray of your knee at this stage.