A Patient’s Guide to Hip Resurfacing
Contents Hip Replacement
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Hip Resurfacing
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Who is a Candidate for Hip Resurfacing
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Results of Hip Resurfacing
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Disadvantages of Hip Resurfacing
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Diseases of the Hip
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Hip Resurfacing: Pre-Op and Surgery Day
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Preventing Post-Operative Complications
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NICE Guidelines
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A Patient’s Guide to Hip Resurfacing
Hip Replacement Conventional Total Hip Replacement is a very successful procedure for the treatment of Hip Arthritis. The purpose of total hip replacement is to remove the two damaged and worn parts of the hip joint - the hip socket (acetabulum) and the ball (femoral head) - and replace them with smooth, artificial implants called prostheses, which will help make the hip strong, stable, and flexible again. For younger, more active people needing a hip replacement there is a high chance that a traditional hip replacement will wear out during their lifetime and need to be replaced again - a second replacement (revision) is much more difficult and consequently may last a shorter time than the original replacement. In addition, high impact activities and activities requiring extreme positions traditionally have not been recommended following total hip replacement.
Hip Resurfacing Hip Resurfacing is a type of hip replacement which replaces the two surfaces of the hip joint. The procedure is very bone conserving as the head of the femur is retained. Instead of removing the head completely, it is shaped to accept an anatomically sized metal sphere. Advantages include saving bone, less bone loss over time from the absence of a stem down the femur (thigh bone), a lower risk of dislocation compared to traditional total hip and the potential for a higher activity level. The resurfacing components are made of ‘as-cast’ cobalt chrome which is finely machined to produce a very high quality surface with a low friction finish, hence low wear. The BIRMINGHAM HIP™ Resurfacing System (BHR™) from Smith & Nephew has the largest independently verified clinical history of any resurfacing device available today.
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Total Hip Replacement
Hip Resurfacing
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A Patient’s Guide to Hip Resurfacing
Who is a Candidate for Hip Resurfacing This operation is primarily intended for use in people who are in need of a hip replacement at a younger age. There are certain causes of arthritis of the hip which mean that this technique cannot be used - namely those which have resulted in extreme deformity of either the head of the femur or the acetabulum. For people needing a replacement under the age of 55, regular consideration is given for this procedure. People aged between 55 and 65 who are very active and otherwise fit may also be suitable and this will be determined by their bone quality and activity level. The procedure is rarely considered for people over the age of 65 however because a conventional type of hip replacement in somebody of this age group stands an extremely good chance of lasting them the rest of their lives. Patients who need to have hip replacements under the age of 50 - 55, assuming they have normal life span, have a very high chance that the conventional hip replacement will wear out and need to be replaced during their lifetime - hence the resurfacing procedure offers potentially significant advantages in this group.
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Results of Hip Resurfacing The long term results of this procedure are not yet known as it has only been in clinical usage in its current form for 10 years, however, the results over this period have been very good and all at least as good as conventional hip replacement. The long term reliability of the implant will not be known until it has been in widespread usage for 15 to 20 years. The historical metal on metal devices which share their metallurgical heritage with the BIRMINGHAM HIP™ Resurfacing System have been shown to last in excess of 30yrs. Only a small number of these historical devices have survived however, due to the inconsistencies in manufacturing at that time. With modern manufacturing and quality control techniques we are confident in the BIRMINGHAM HIP Resurfacing product.
Disadvantages of Hip Resurfacing The main disadvantage lies in not knowing the long term results. The results to date indicate that the success rate of hip resurfacing after the first 5-10 years is better than those of conventional total hip replacement. Although the operation for hip resurfacing is similar to a conventional total hip replacement, in some ways it is a more demanding surgical technique which requires special training. Some concerns have been raised about the release of metal ions into the body, however, to date no statistical correlation with long term systemic problems have been demonstrated, although work is still on going. It is worth noting that in the patients with historical metal on metal devices, some of which have been implanted for very long periods, no adverse reactions have been highlighted. The usual risks associated with any hip replacement therefore apply - there is a very low risk of major complications due to infection or early loosening - thus leading to the need for further surgery. There is a lower risk of leg lengths being different. There is also a very low risk of major medical complications such as thrombosis, heart attack or stroke. This is the same for any surgery requiring an anaesthetic.
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A Patient’s Guide to Hip Resurfacing
Socket
Rough bone
Ball
Bone spurs
Smooth weightbearing surfaces
Smooth cartilage
Irregular weightbearing surfaces
Femur
Worn cartilage
Narrowed joint space
Diseases of the Hip There are four primary diseases of the hip that may indicate the need for BIRMINGHAM HIP™ Resurfacing.
Osteoarthritis Osteoarthritis of the hip is a disease which wears away the cartilage between the femoral head and the acetabulum, eventually causing the two bones to scrape against each other, raw bone on raw bone. When this happens, the joint becomes pitted, eroded and uneven. The result is pain, stiffness and instability, and in some cases, motion of the leg may be greatly restricted. Patients with osteoarthritis often develop large bone spurs, or osteophytes, around the joint, further limiting motion. Osteoarthritis is a common, degenerative disease, and although it most often occurs in patients over the age of 50, it can occur at any age, especially if the joint is in some way damaged. Causes Osteoarthritis of the hip is a condition commonly referred to as “wear and tear” arthritis. Although the degenerative process may accelerate in persons with a previous hip injury, many cases of osteoarthritis occur when the hip simply wears out. Some experts believe there may exist a genetic predisposition in people who develop osteoarthritis of the hip. Abnormalities of the hip due to previous fractures or childhood disorders may also lead 8
to a degenerative hip. Osteoarthritis of the hip is the most common cause for both total hip replacement and hip resurfacing. Symptoms The first and most common symptom of osteoarthritis is pain in the hip or groin area during weight bearing activities such as walking. People with hip pain usually compensate by limping, or reducing the force on the arthritic hip. As a result of the cartilage degeneration, the hip loses its flexibility and strength, and may lead to the formation of bone spurs. Finally, as the condition worsens, the pain may be present all the time, even during non weight-bearing activities.
Rheumatoid Arthritis Unlike osteoarthritis, which is a “wear and tear” phenomenon, rheumatoid arthritis is a chronic inflammatory disease that results in joint pain, stiffness and swelling. The disease process leads to severe, and at times rapid, deterioration of multiple joints, resulting in severe pain and loss of function. Causes Although the exact cause of rheumatoid arthritis is unknown, some experts believe that a virus or bacteria may trigger the disease in people having a genetic predisposition to rheumatoid arthritis. Many doctors think rheumatoid arthritis is an autoimmune disease in which the synovial tissue of the joint is attacked by one’s own immune system. The onset of rheumatoid arthritis occurs most frequently in middle age and is more common among women. Symptoms The primary symptoms of rheumatoid arthritis are similar to osteoarthritis and include pain, swelling and the loss of motion. In addition, other symptoms may include loss of appetite, fever, energy loss, anaemia, and rheumatoid nodules (lumps of tissue under the skin). People suffering with rheumatoid arthritis commonly have periods of exacerbation or “flare ups” where multiple joints may be painful and stiff.
Developmental Dysplasia of the Hip Developmental dysplasia of the hip (DDH), also called hip dysplasia, is a lifelong condition, shared by one in 1,000 people. Because DDH patients are born with an altered hip anatomy, the joint doesn’t develop the normal wear patterns over the years. This leads to “wear and tear” arthritis at a relatively early age. 9
A Patient’s Guide to Hip Resurfacing Causes The most significant risk factor for DDH is a family history of the disorder. Women have a higher rate of DDH, as do first-born children and babies delivered breech. Diagnosis Developmental dysplasia of the hip often can be diagnosed in the first year of life. Symptoms include diminished leg movement in the affected hip, shortening of the leg on the affected side, or asymmetry in leg positions. One or both hips may have DDH.
Avascular Necrosis Avascular necrosis (AVN) of the hip results when poor blood circulation starves the bones that form the hip joint. In time, the starved bone dies, and the hip joint collapses. AVN, sometimes called hip osteonecrosis, is most prevalent in younger or middle-aged adults. Causes Alcoholism and corticosteroids are by far the leading causes of AVN. In rarer cases, AVN can result from a blockage in blood vessels from sickle cell anaemia or fat particles, or from dislocation of the hip due to trauma. Symptoms Hip pain, especially after standing or walking, is the most common symptom. Hip AVN most commonly afflicts the femoral head, where the femur (or thighbone) attaches to the pelvis (or hip bone). The femoral head may weaken and collapse.
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Hip Resurfacing: Pre-op and Surgery Day Once you and your orthopedic surgeon decide that hip resurfacing is right for you, the days and weeks leading up to surgery, as well as the day of surgery, require preparation. The following is a description of what you may expect.
Pre-operative Procedure You and your orthopedic surgeon may participate in an initial surgical consultation. This appointment may include pre-operative X-rays, a complete medical and surgical history, physical examination, and a comprehensive list of medications and allergies. During this visit, your orthopedic surgeon will likely review the procedure and answer any questions.
Surgery The Surgeon will start the operation with a technique to approach the hip joint. There are several different surgical approaches which can be used and an individual Surgeon will choose that which he finds suits his experience the best. There are subtle nuances in each of these approaches and these will result in slight variations with the post operative regimes used in the recovery and rehabilitation from the surgery. This is normal and correct. The bone preparation part of the operation is carried out using the specialist instruments supplied by Smith & Nephew. The head of the femur is prepared to receive the resurfacing component and the socket is shaped to accept the new resurfacing cup. Once this is accomplished the socket is inserted in a position to give stability to the hip and allow the bone to grow around it encouraging long term security, the resurfacing component is then fixed into position using bone cement. Following a careful inspection of all components the Surgeon will then ‘close’ the surgical approach path and finally the skin with either sutures or metal staples. It is common to have a drainage tube exiting from just below the wound for a couple of days although in some cases it is not required.
Recovery Your recovery program usually begins the day after surgery. Many patients walk a few steps the day following surgery with an appropriate assistive device (usually crutches or walking sticks) and this is acceptable permitting it is within the limits of your comfort.
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A Patient’s Guide to Hip Resurfacing The surgeon will determine how much weight you can bear on your new hip. In certain instances where the surgery has been more difficult, as is often the case with more advanced hip disease, the Surgeon will advise you on walking and any further rehabilitation measures. This may mean a period of several weeks on crutches to allow full healing. For young, healthy patients, full weight-bearing is often allowed within the first week and normal walking resumes by 4-6 weeks. It should be noted that the first 6 months post-operation are the most vulnerable period for the joint as it is during this period that the bone initially remodels to ‘grip’ the implant. During this period impact at the joint should be avoided.
Further Progress You will generally be discharged from the hospital after five to seven days with an assistive walking device. While at home, continue to walk with an assistive device unless directed by your surgeon to discontinue use. You must also remember to strictly follow the hip precautions and weight-bearing instructions during the first few months following surgery. In the weeks after your surgery, it is important to continue to walk on a regular basis to further strengthen your hip muscles. An exercise and walking program helps to enhance your recovery from surgery and helps make activities of daily living easier to manage. Driving may be commenced around 4-5 weeks after surgery although it is recommended that you do not drive unless you have been approved by your doctor. Sexual relations can normally resume at around four to six weeks, however, you should take care to avoid extreme movements of the hip until around three months. The following guidelines are important during your recovery; 1. Take regular walks when able 2.Continue the exercises the physiotherapist has shown you 3.Lie flat on your back for an hour every day to encourage the stretching of your hip muscles and ligaments 4.Ensure that you rest after walking to enable the soft tissues to recover 5.Avoid weights or resistive exercises until your first follow-up visit (usually at 6 weeks).
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Preventing Post-Operative Complications As with any major surgical procedure, post-operative complications can occur following hip resurfacing surgery. To follow is a list of precautions which must be taken to prevent any complications occurring; 1. No heavy lifting, weights or resistive exercise 2.Do not twist or squat while lying or standing 3.Avoid extreme movements of the new hip 4.Do not cross your legs 5.Do not lift your knee higher than your hip on the operated side You should not attempt sporting activities (including Golf) other than swimming until given clearance by your Surgeon.
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A Patient’s Guide to Hip Resurfacing
NICE Guidelines In April 2002, the National Institute for Clinical Excellence, the government body which reviews and gives judgement on all products associated with the medical and pharmaceutical industries, issued guidance that recommended the selective use of metal-on-metal hip resurfacing. The main points of the guidance state that; • Hip resurfacing is considered as an option for people with advanced hip disease who would otherwise receive and are likely to outlive a conventional primary total hip replacement. • Hip resurfacing arthroplasty should only be performed by a Surgeon who is trained specifically in the technique. • The informed consent of the patient should include information about the safety and reliability of the device and the likely outcome of revision surgery in comparison to conventional total hip replacement. Additionally, due to the need to gather clinical effectiveness and cost data on the use of this technology, details of all patients should be submitted for inclusion in the UK national joint register. The full NICE ‘Final Appraisal Determination on metal on metal hip arthroplasty’ is available on the NICE website at www.nice.org.uk
Summary Although Hip Resurfacing is relatively new procedure, it holds out great promise for the younger more active high demand patient as it retains the maximum amount of your own bone and in many cases will allow return to a very high activity level. The modern generation of metal-on-metal resurfacing implants stem from the concept of Mr Derek McMinn FRCS. Over a period of some years he honed the design of metal-onmetal resurfacing into the BIRMINGHAM HIP™ Resurfacing System, leaving behind the deficiencies of the earlier developmental designs. Today the only device endorsed by Mr McMinn is the BIRMINGHAM Hip Resurfacing from Smith & Nephew.
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A Patient’s Guide to Hip Resurfacing
Acknowledgments Smith & Nephew gratefully acknowledges the assistance of Mr P W Howard FRCS (Derby) and MR J N O’Hara FRCS (Royal Orthopaedic Hospital, Birmingham) in the production of this booklet.
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Smith & Nephew Orthopaedics Ltd 1 Kingmaker Court Warwick Technology Park Gallows Hill Warwick CV34 6WG United Kingdom Telephone +44 0 1926 482400 Fax +44 0 1926 482492 www.smith-nephew.com
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12/06
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