Total Hip Replacement (THR)
Other popular names
- Minimally Invasive Total Hip Replacement
- Hip Arthroplasty
- Cemented Hip Replacement
- Cementless Hip Replacement
- Hybrid Hip Replacement
Who does it affect?
Osteoarthritis of the hip is the most common reason for a hip replacement. Osteoarthritis is caused by the wear and tear of aging. It causes the cartilage covering the joint surfaces to wear out, resulting in pain and stiffness.
Other conditions that can cause destruction of the hip joint include loss of the blood supply to the head of the thighbone (osteonecrosis), rheumatoid arthritis, injury, infection, and developmental abnormalities of the hip. Patients with arthritis may also have brittle bones (osteoporosis), but there is no direct relationship between bone density and the development of arthritis of the hip.
Hip arthritis typically causes pain that is dull and aching. The pain may be constant or it may come and go. Pain may be felt in the groin, thigh, and buttock, or there may be referred pain to the knee. Walking, especially for longer distances, may cause a limp.
Some patients may need a cane, crutch, or walker to help them get around. Pain usually starts slowly and worsens with time and higher activity levels.
Patients with hip arthritis may have difficulty climbing stairs. Dressing, tying shoes, and clipping toenails can be difficult or impossible. Pain may also interfere with sleep.
Your consultant will readily be able to diagnose hip arthritis. This will be done through a physical examination, supported by X-ray. The x-ray may show loss of the cartilage space in the hip socket and a "bone-on-bone" appearance. Bone spurs and bone cysts are common.
Depending upon the extent of your condition, you may be referred for an MRI, which will provide a greater level of detail to your consultant.
Hip arthritis is never life threatening, the main aim of treatment is therefore symptomatic for pain and to try to keep mobility and range of movement of the joint. Treatment follows a progression from simple measures to major surgical intervention. There are a range of non-surgical approaches to be exhausted prior to the need for surgical intervention:
- Exercise – Low impact exercise such as walking, swimming and cycling keeps muscle strength and tone. Hip joint stretches to keep the hip supple are beneficial. A consultation with a physiotherapist for education and a home exercise program can be useful.
- Walking stick – Using a walking stick in the opposite hand reduces load in the hip and usually increases your walking distance. A strong stick of correct length with a non-slip rubber end is best.
- Paracetamol – A simple but safe analgesic when used correctly. Often needs to be used 3 or 4 times a day (1000mg / 2 tablets on each occasion). This can be safely used by most people at prolonged periods at these doses.
- Natural remedies – Often not proven but some people gain relief from various naturopathic potions, magnets, acupuncture and the like. This affect may be placebo but some plant substances have proven anti-inflammatory effects. You should check the use of these with your local Doctor as some may react with other medicines or be dangerous.
- Glucosamine and Chondroitin Sulphate – The most common arthritis remedies at the present time. There is some early evidence that over time they may help to maintain articular cartilage and slow progression of Osteoarthritis. Nothing can ‘put cartilage back’ after Osteoarthritis is established. Some people also report a reduction in arthritis symptoms when taking these substances. Their main side effect is diarrhoea. They should not be taken if you are pregnant or allergic to shellfish.
- Fish oils – Have been associated with some improvement in cartilage quality and may be beneficial.
- Anti-inflammatories (NSAID’s) – Several types of Non-steroidal anti-inflammatory drugs are available. They can be very effective in reducing pain and swelling associated with osteoarthritis. All these medications have potential side effects and are not always tolerated. The most common effects are: exacerbating asthma, stomach upset (ulcers etc), increased blood pressure and ankle swelling.
- Weight loss – There is no doubt that if you are above ideal weight, weight loss can have a significant impact in reducing pain from osteoarthritis. Weight loss can also reduce the risk of anaesthetic complications and wound healing. Many people after losing weight no longer need surgery for their Osteoarthritis. You may be given an ideal weight to attain prior to consideration for surgery. Consulting a dietician may be beneficial.
- Injections – A hip injection is often used by your orthopaedic consultant to differentiate between back pain and hip joint pain. An injection is given to ‘numb’ the hip and you then keep a record of the pain experienced. Sometimes steroids are used to provide longer relief of pain. The procedure is done under X-ray guidance with a small risk of infection.
Pain and mobility may worsen with hip osteoarthritis, even when all of the recommended nonsurgical treatments have been tried. If this happens, your consultant may recommend surgery. Surgical options include:
- Arthroscopy. Arthroscopy of the hip is a minimally invasive procedure that is relatively uncommon. Your consultant may recommend this it if the hip joint shows evidence of torn cartilage or loose fragments of bone or cartilage.
- Osteotomy. Candidates for osteotomy include younger patients with early arthritis, particularly those with an abnormally shallow hip socket (dysplasia). The procedure involves cutting and realigning the bones of the hip socket and/or thighbone to decrease pressure within the joint. In some people, this may delay the need for replacement surgery for 10 to 20 years.
More often, you will require hip replacement. There are a number of options available and types of implants.
Traditional Hip Replacement
Traditional hip replacement surgery involves making a 10- to 12-inch incision on the side of the hip and takes 60 – 90 minutes. The muscles are split or detached from the hip, allowing the hip to be dislocated.
Once the joint has been opened up and the joint surfaces exposed, the surgeon removes the ball at the top of the thighbone, or femur. The hip socket is prepared by removing any remaining cartilage and some of the surrounding bone. A cup-shaped implant is then pressed into the bone of the hip socket. It may be secured with screws. A smooth plastic bearing surface is then inserted into the implant so the joint can move freely.
Next, the femur is prepared. A metal stem is placed into the femur to a depth of about 6 inches. The stem implant is either fixed with bone cement or is implanted without cement. Cementless implants have a rough, porous surface. It allows bone to adhere to the implant to hold it in place. A metallic ball is then placed on the top of the stem. The ball-and-socket joint is recreated.
(Left) The individual components of a total hip replacement. (Center) The components merged into an implant. (Right) The implant as it fits into the hip.
X-rays before and after total hip replacement. In this case, non-cemented components were used.
Minimally Invasive Hip Replacement
Minimally invasive hip replacement surgery allows the surgeon to perform the hip replacement through one or two smaller incisions.
Candidates for minimal incision procedures are typically thinner, younger, healthier, and more motivated to have a quick recovery compared with patients who undergo the traditional surgery.
The artificial implants used for the minimally invasive hip replacement procedures are the same as those used for traditional hip replacement. Specially designed instruments are needed to prepare the socket and femur and to place the implants properly.
The surgical procedure is similar, but there is less soft-tissue dissection. A single minimally invasive hip incision may measure only 3 to 6 inches. It depends on the size of the patient and the difficulty of the procedure.
The incision is usually placed over the outside of the hip. The muscles and tendons are split or detached, but to a lesser extent than in the traditional hip replacement operation. They are routinely repaired after the surgeon places the implants. This encourages healing and helps prevent dislocation of the hip.
Two-incision hip replacement involves making a 2- to 3-inch incision over the groin for placement of the socket. A 1- to 2-inch incision is made over the buttock for placement of the stem.
To perform the two-incision procedure, the surgeon may need guidance from X-rays. It may take longer to perform this surgery than it does to perform traditional hip replacement surgery.
Benefits of minimally invasive hip replacement include:
- Less pain
- Improved cosmetic appearance
- Less muscle damage
- Rehabilitation is faster
- Hospital stays are shorter
For traditional hip replacement, hospital stays average 3 to 5 days. Many patients need extensive rehabilitation afterward. With less-invasive procedures, the hospital stay may be as short as 1 or 2 days. Some patients can go home the day of surgery.
Early studies suggest that minimally invasive hip replacement surgery streamlines the recovery process, but the risks and long-term benefits of less-invasive techniques have not yet been documented.
The anaesthetic will wear off after approximately 6 hours. Simple analgesia (pain killers) usually controls the pain and should be started before the anaesthetic has worn off. Typical post-surgery may be:
- Day 1: Mobilise with physiotherapy and a frame/crutches.
- Day 2: Mobilise with physiotherapy and independently with elbow crutches/walking sticks.
- Day 3-5: Return home. Before leaving hospital you will be given an appointment for the outpatients clinic. This appointment is a routine check-up to ensure that you are making satisfactory progress. It is likely that you will also be offered physiotherapy to aid your rehabilitation and improve your recovery time. Once you return home, you may need to continue to take your painkillers if you need to, as advised by your surgeon. You may also be advised to continue to wear compression stockings. Walking without the aid of a stick is often possible from four to six weeks following surgery, although this will be determined by your confidence and progress and you should follow the advice from your surgeon and physiotherapist. You will be fully weight bearing six weeks following surgery and it is important that if you have any problems that you contact your surgical team immediately. Six weeks following your surgery you may return to driving, low impact sports and work although this may depend on your employers’ liability insurance. Some patients experience swelling of the thigh on the operated side, but this usually disappears within three months. A few patients may experience clicking or other sounds from their new hip, but this rarely causes problems and usually disappears after a few months.
The large is normally removed 24-48 hours after surgery.
Sutures are removed after 10 days.
Return to normal routine
Bathing and showering
The wounds should be kept clean and dry until the wound has sealed. Showering is fine and the waterproof dressings can be changed afterwards. Bathing is best avoided until the wounds are sealed, typically 10 days after surgery.
In summary, whilst the wounds are wet - keep them dry and when the wounds are dry, you can get them wet!
Surgery is followed by a prolonged course of physiotherapy. This requires a commitment to undertake this rehabilitation in order to achieve the best possible result (at least half an hour per day for 6 months). It is vitally important to stay within the post-operative activity restrictions an physiotherapy guidelines to avoid damaging stretching your reconstructed ligament.
Return to work
The timing of your return to work depends on the type of work and your access, however, the following is a general guide:
- Desk work: as soon as pain allows and you can travel easily to and from work (2 weeks)
- Light duties: if the job allows partial use of crutches or limited walking (2-5 weeks). If the job involves standing for prolonged walking, bending, lifting, stairs but no squatting (7-8 weeks)
- Heavy duties: full squatting, heavy lifting, digging, in and out of heavy machinery, ladder work etc (3-4 months)
When you can walk without crutches or a limp and be in control of your vehicle (about 4-6 weeks).
Failure of Hip Replacement
Hip replacements can fail in the early stage because of infection and this can occur within the first two years and requires further surgery to remove the infection and then implant a new hip.
A previously well-functioning hip replacement that then becomes painful in later years fails either because the bearing surface wears out or the implant becomes loose from the bone.
Wear - As can be seen in this X-ray here – the plastic bearing is actually very thin at the top.
Aseptic loosening - This presents with a hip replacement that was pain free for many years and then pain develops in the groin and the thigh. The X-ray shows the left hip socket has actually flipped out of the bone altogether. In this example, the stem is loose from the cement and has sunk within the bone, the cement has fractured and the femur is weak (lytic).
Treatment Options - With aseptic loosening and wear of the component the only treatment option is surgery and this is very commonly done and very successfully done and Mr Tony Maury spent a very enjoyable year in Toronto, Canada working for a world expert in revision joint surgery.
The following X-ray shows how the loose joint can be replaced and the area of thin bone can be bypassed with modern contemporary devices:
Hip replacement surgery, whilst being one of the most successful operations in the whole of surgery, is still a major operation with complications.
Nonetheless, the vast majority of patients are delighted with the outcome because their pain goes and they can expect at least ten to twenty pain free years before further surgery is necessary.
There are risks of:
- Leg length discrepancy
- Infection causing early loosening of the components and wear of the components.
- There is also a small risk of blood clots in the legs (DVT).
All these risks are uncommon and in total, the chance of you or your hip being worse off in the long term is about or less than 1%.