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Hip Replacement Manual.doc

  2. 2. This booklet is the original work of John R. Moreland, M.D. Dr.Moreland requests that his material not be reproduced withouthis written permission. Additional booklets can be obtained bycalling or writing his office. January 2008..................................................................... 1 2
  4. 4. WHAT ABOUT OTHER TREATMENTS?........................................ 14WHEN SHOULD I HAVE MY HIP REPLACED?................................. 14CAN I PUT OFF SURGERY?.............................................. 15ARE THERE OTHER SURGICAL TREATMENT ALTERNATIVES?.................... 16WHAT IS THE HISTORY OF HIP REPLACEMENT SURGERY?..................... 16WHY IS IT CALLED A TOTAL HIP REPLACEMENT?........................... 17WHAT ARE THE PROBLEMS WITH CEMENTED HIP REPLACEMENT?................ 18ARE THERE MORE DURABLE ALTERNATIVES?................................ 18WHAT ARE THE PROBLEMS WITH POROUS HIP REPLACEMENT?.................. 19WHAT AFFECTS CHOICE OF PROSTHETIC FIXATION TYPE?.................... 20WHAT ABOUT THE HYBRID HIP REPLACEMENT?.............................. 21SHOULD THE PATIENT DECIDE IMPLANT TYPE?............................. 21WHAT ABOUT SURFACE REPLACEMENT?..................................... 22WHAT ABOUT OTHER NEW TECHNIQUES?.................................... 23WHAT ARE THE COMPLICATIONS OF HIP REPLACEMENT?...................... 24IS WEAR A PROBLEM?.................................................. 25WHAT IS A HIP REPLACEMENT DISLOCATION?.............................. 27WHAT ABOUT OTHER POSSIBLE COMPLICATIONS?............................ 28WHAT ABOUT WRONG SIDE SURGERY?...................................... 29WHAT ABOUT OTHER NEW TECHNIQUES?.................................... 30WHAT ARE THE COMPLICATIONS OF HIP REPLACEMENT?...................... 34INITIAL CONSULTATION WITH DR. MORELAND.............................. 34INITIAL CONSULTATION WITH DR. MORELAND.............................. 35SURGICAL SCHEDULING................................................. 35AUTOLOGOUS BLOOD DONATION........................................... 35WHAT SHOULD I AVOID PRIOR TO SURGERY?............................... 36 4
  5. 5. THE PREOPERATIVE VISIT.............................................. 37WHAT DO I BRING TO THE HOSPITAL?.................................... 37WHAT DO I BRING TO THE HOSPITAL?.................................... 37WHAT HAPPENS THE DAY OF SURGERY?.................................... 37THE HOSPITAL STAY................................................... 39DISCHARGE FROM THE HOSPITAL......................................... 42WHAT ABOUT FOLLOW-UP APPOINTMENTS?.................................. 42HOW CAN I PREPARE MY HOME?.......................................... 43HOW CAN I PREPARE MY HOME?.......................................... 43DR. MORELAND’S HIP OPERATION DATA................................... 45 5
  6. 6. WHERE AND WHAT IS THE HIP?In everyday language the buttock area is usually called the hip. In anatomical terms used byphysicians, however, the hip is actually the ball and socket joint where the femur (thigh bone)meets the pelvis. The top end of the femur is shaped as a round ball (femoral head) whichnormally rotates in a shallow cup or socket (acetabulum) formed by the pelvic bones. In ahealthy hip, the head of the femur is covered with a layer of a smooth and slippery whitesubstance about one-eighth of an inch thick called articular cartilage. The acetabulum is alsolined with this same type of articular cartilage. When the hip joint moves, the cartilage-coveredfemoral head rotates in the cartilage-lined acetabulum. Articular cartilage has no nerve endingsto transmit signals to the brain and thus we are not aware of movement between the twocartilage layers. Little friction is generated and no discomfort is felt. Since cartilage does notstop x-rays and thus does not show up on x-ray film, an x-ray of the hip will normally showabout a one-quarter inch space between the bony edge of the femoral head and the bonyedge of the socket. WHAT MAKES A HIP HURT?In almost all types of hip disease, the articular cartilage has deteriorated and is partially orcompletely absent. Without the articular cartilage layer, the bone of the femoral head will rubon the acetabular bone of the pelvis. X-rays will then show the femoral bone touching theacetabular bone, since the cartilage layers are absent. This bone-on-bone contact usuallycauses pain. Early in the course of hip arthritis the cartilage space will narrow and patientsusually have mild pain. As the disease process progresses, the bones will gradually movecloser together on the x-ray as the cartilage layer is lost. As the bones touch over largerareas, the pain usually will gradually worsen. A hip replacement is just a complicatedreplacement for the missing cartilage.The cartilage-covered femoral head can be compared to a man’s head covered with hair.During the process of balding, the man first gets a thinned area of hair, and then the thin areagradually progresses to a small bald spot. Later, the bald spot enlarges. Cartilage loss fromthe femoral head is similar. At surgery the femoral head usually has large areas devoid ofcartilage, but may still have some peripheral cartilage even though the patient has severesymptoms. 6
  7. 7. Many people are surprised to hear that bones are alive and can hurt. Inside the calciumcrystalline structure of bone are nerve cells, which can transmit pain signals to the brain whenthe bones touch. In addition, this bone-on-bone touching often flattens the femoral head bygrinding away some of the bone surface and releasing bone and cartilage fragments to thejoint cavity. These released fragments irritate the lining of the joint (synovium) and cause apainful inflammation of the joint lining (synovitis).At times patients can even hear a creaking noise (crepitation) coming from the hip caused bythe bone-on-bone contact. The bone surfaces often become highly polished and harder fromthis repetitive rubbing. The body often attempts to heal the diseased joint by forming extrabone at the edges of the joint. These extra bone formations can be seen on the x-ray and arecalled spurs, or more scientifically, osteophytes.As the cartilage layer wears out, normal hip flexibility is often decreased by variousmechanisms (pain, high friction, lack of head roundness, osteophyte formation and musclestiffness). This lack of normal hip flexibility can make it difficult to position the legs whenbending over for tasks such as tying shoes or cutting toenails. Many patients with hip stiffnesscannot separate their legs very well, making sexual intercourse difficult for women. Horsebackriding also is commonly uncomfortable, if not impossible. Stiffness can even be so severe asto interfere with personal hygiene.The hip stiffness can make standing up straight difficult and this stiffness may aggravate backproblems, since extra back movement is needed to compensate for the lack of hip flexibility.Hip stiffness can cause an exaggerated curvature in the lower back called (hyperlordosis) andcan cause spinal curvature (scoliosis). Hip stiffness also can cause the pelvis to be held in atilted position, resulting in extra stress on the lumbar spine and making the leg lengthsfunctionally unequal. WHAT IS ARTHRITIS?Joint pain is called arthritis (arthr means joint and itis means inflammation). Thus, patients witharthritis simply have at least one joint causing pain. There are many types of hip arthritis. Themost common type is called primary osteoarthritis, which results from wearing out the articularcartilage of the joint for no identifiable reason. Secondary osteoarthritis is that due to anidentifiable cause. Secondary osteoarthritis can be due to an old hip injury, to conditions withwhich one is born, such as developmental dysplasia of the hip (DDH: a problem of shallowsockets, usually in women), to conditions that develop during childhood such as slipped capitalfemoral epiphysis (SCFE-usually in boys ages 10-13) and Legg-Calve-Perthes disease (LCP:usually in boys ages 3-9), or to arthrocatydesis (Otto pelvis: a condition usually in youngwomen with extra-deep sockets and usually causing more hip stiffness than pain). Thetendency for the hips to wear out during a patient’s lifetime runs in families.Rheumatoid arthritis (RA) is another frequent cause of hip deterioration. The inflammation ofrheumatoid arthritis is a generalized rather than a localized condition, usually affecting manyjoints in the body as well as causing a general ill feeling. The severity of rheumatoid arthritis isvariable and most RA patients are under the regular care of a rheumatologist (an internalmedicine doctor specially trained in diseases which cause joint problems but who does not dosurgery). Rheumatologists and orthopedists often work together in the care of patients withRA. Certain powerful drugs such as gold, methotrexate, penicillamine and prednisone areoften used by the rheumatologist to control the joint pain and swelling. Patients, who take thesteroid drug, prednisone, need extra amounts of steroid during the surgical period. All these 7
  8. 8. powerful drugs have the potential for significant side effects and require regular follow-up withthe rheumatologist. Over the last several years, some new and quite effective drugs to combatrheumatoid arthritis have come on the market.RA is probably an autoimmune disease (a disorder of the immune system in which thepatient’s tissues come under attack by the patient’s own immune system). Patients with RAsometimes develop deterioration of the neck bones causing spinal instability and have anincreased risk of spinal cord damage during any general anesthesia. Neck stability x-raysbefore surgery and special anesthesia techniques may be necessary. Patients with RA alsosometimes have arthritis of the jaw joint (temporomandibular joint) causing difficulty in openingthe mouth wide enough for the usual anesthesia techniques. Special anesthesia equipmentand techniques may be needed for such patients.Children can get a variation of RA called juvenile rheumatoid arthritis (JRA). These childrensuffer joint inflammation and resultant damage during childhood and may need hipreplacement even as a child but more commonly when they become adults.Ankylosing spondylitis (AS) is another type of inflammatory arthritis that can damage the hips.Ankylosing spondylitis usually affects men. Patients suffer stiffening of the back and neck,making it difficult sometimes to see straight ahead. The neck stiffness of AS can make the jobof the anesthesiologist difficult and special anesthetic techniques and instrumentation may benecessary.Other inflammatory conditions such as systemic lupus erythematosis (SLE or lupus), psoriaticarthritis, and inflammatory bowel arthritis can also cause hip disease. WHAT IS OSTEONECROSIS?Osteonecrosis is a condition in which parts of the femoral head die (osteo means bone andnecrosis means death). If extensive, the dead bone cannot stand up to the stress of walkingand the femoral head loses its roundness, resulting in pain. The most common causes ofosteonecrosis (also called aseptic necrosis and ischemic necrosis) are oral steroid intake (suchas prednisone), excessive alcohol intake and trauma. Other causes are hyperuricemia,systemic lupus erythematosis (SLE), sickle cell syndrome, Gaucher’s disease, pancreatitis,pregnancy, liver disease, the bends, caisson disease, polycythemia, diabetes, obesity, andhyperlipidemia. Sometimes, no reason can be found for osteonecrosis (idiopathicosteonecrosis).It is helpful to understand osteonecrosis by using the analogy of a building. Buildings are deadbut the people inside are alive and maintain the building. Window breakage is repaired androof leaks are fixed as these problems occur. Without such maintenance, buildings will decayand eventually fall down. The calcium crystal structure of the femoral head is not alive but thetiny bone cells in the bone are. These bone cells maintain the bones just as humans maintainbuildings. When a portion of a bone dies, what really happens is bone cell death. Withoutbone maintenance the bone structure usually deteriorates in a year or two. Thus, there isusually a delay between bone death and the onset of symptoms.Very early in the problem of osteonecrosis when the femoral head is still round, a procedurecalled core decompression is sometimes performed in which a hole is drilled up into thefemoral head to decrease an abnormally elevated pressure in the femoral head. Thistreatment may relieve pain as well as allow blood supply to return to the femoral head. Coredecompression is controversial and is not universally accepted by orthopedic surgeons as avalid treatment. 8
  9. 9. When the femoral head loses its roundness from osteonecrosis, the usual treatment is hipreplacement, if the symptoms are sufficiently severe. Rarely, surgery is performed in which thebones are purposely broken (osteotomy) and their position rearranged to take advantage ofthose portions of the femoral ball which are still intact.Bone grafting is also sometimes used for osteonecrosis. Bone from cadavers or from otherparts of the patient’s body (usually the fibula) is placed in the femoral head through a holedrilled into the femoral head. This highly complex, technically difficult, and long (six to eighthours) surgical technique is rarely performed. It involves placing a piece of the fibula with itsblood vessels into the femoral head with the blood vessels then connected to hip area bloodvessels. This procedure, developed at Duke University, is not generally accepted by theorthopedic community and is considered unproven and experimental. WHAT IS OSTEOPOROSIS?The terms osteoporosis (literally “porous bone”) and osteoarthritis are often confused.Osteoarthritis, as explained above, is a problem with a joint. Osteoporosis is a condition of softbones. Osteoarthritis involves pain coming from the joints. Osteoporosis does not hurt unlessthe softened bones fracture, as they frequently do if the osteoporosis becomes severe. WHERE WILL I FEEL HIP PAIN?Pain from the hip joint is usually felt in the groin (in the front of the body where the thigh joinsthe torso). The pain often radiates down the front of the thigh to the knee and sometimes tothe mid-shin. Pain, which is perceived in areas of the body remote from the actual problem, istermed referred pain. You may be aware that referred pain from the heart is usually felt in theleft side of the neck and in the left arm, and referred pain from the diaphragm is felt in theshoulder. The referred pain of the hip to the anterior thigh and knee occurs because the nerveroot supply to the hip and the anterior thigh and knee are the same. In some cases, thereferred pain to the knee area is so prominent that the patient, and sometimes even thephysician, thinks the knee itself is diseased, when really the hip is the problem.Lower back pain is often confused with hip disease. Pain from the spine is usually felt acrossthe low back, in the buttock, down the back of the thigh, and often down to the foot. Painradiating in these areas from the spine is called sciatica. Sciatica is often accompanied bynumbness and tingling, whereas hip pain is not. Most pain felt in the back of the body in thebuttock area is coming from the spine. Most pain felt in the front of the body in the groin and inthe front part of the thigh is coming from the hip. Patients often expect the hip to cause pain inthe buttock, but buttock pain is usually coming from the low back or the sacroiliac joint. Thebuttock is not the anatomical hip, although the buttock is usually referred to as the hip ineveryday language. Patients with hip problems also often have lower back pain since theaccompanying hip stiffness puts extra stress on the spine and since back pain, even withouthip arthritis, is very common.This confusion of hip problems with back and knee problems often obscures and delays thediagnosis of hip disease. Sometimes back or knee operations are tragically done by mistakefor patients when the real problem is the hip.Another disease entity often confused with hip arthritis is greater trochanteric bursitis. This isan inflammation of the soft tissues just superficial to the greater trochanter (the bump of bonein the area of your hip on which you lie when you are on your side). Patients notice pain (oftenburning in character) and tenderness over the greater trochanter. Pain can radiate down the 9
  10. 10. outside of the thigh. Patients can develop a painful and sometimes audible snap or pop overthe greater trochanter with certain movements. Trochanteric bursitis is seen most frequently inyoung adult women. Treatment is usually with NSAIDS, steroid injections and education.Patients often see several physicians before this problem is correctly diagnosed.It is, of course, possible to be bothered by back pain, hip arthritis pain, and trochanteric bursitispain all at the same time, and deciding which is the main problem can be difficult. Fixing anarthritic hip with a total hip replacement often helps the commonly accompanying back pain.Back surgery, on the other hand, will not help an arthritic hip and, in fact, the failure rate ofback surgery (already higher than hip surgery) is increased further for patients who also havean arthritic hip. Thus, patients with an arthritic hip and a bad back are almost always better offhaving the hip replaced before having back surgery. In many instances, the best way torelieve back pain in a patient with hip arthritis is to replace the hip. WHAT ARE THE NON-OPERATIVE TREATMENTS OF HIP ARTHRITIS?The hip is the most important joint of the body for walking and thus, a person with hip pain hasa very serious disability. The more a patient with hip arthritis walks, the more the hip willusually hurt. Often the first one or two steps after prolonged sitting or lying down may beparticularly painful. We call this start-up pain. Patients can minimize hip pain by simplydecreasing life’s activities: the elevator can be used rather than walking stairs, lifting can beminimized, the patient can allow the car driver to let him or her out at the front of destinationsand all long walks can be avoided. Running and playing vigorous sports such as tennis willalmost always significantly increase the discomfort.All exercise involving an arthritic hip joint can increase hip inflammation and consequently,aggravate hip pain. Remember that exercise strengthens muscles but at the same time putsincreased stress on the joints. Many people assume incorrectly that the more exercise thebetter. Exercise may help if you have significant muscle weakness, but the more exercise thebetter is actually not good advice for an arthritic hip. Actually, rest is the most dramatic way ofdecreasing hip pain, since rest will decrease the hip inflammation and thus give pain relief.You may have noticed that if you are not active for a few days, the hip pain is a lot less and ifyou become very active for a period of time, you may have pain at the end of the vigorousactivity or increased pain for the next few days. A sedentary life, besides being inconvenient,can lead to a decrease in muscle and bone strength as well as depress your morale, whichsometimes results in a significant loss of interest in life’s activities.As you probably know, the State of California provides special handicapped parking for peoplewith difficulty walking. Ask our office personnel if you qualify and we will help you submit theproper forms for this. WHAT MEDICATIONS ARE USED FOR HIP ARTHRITIS?A large group of drugs called non-steroidal anti-inflammatory drugs (NSAIDS) can decreasethe inflammation that develops around an arthritic hip and lessen the pain. These drugs do notslow the progression of hip arthritis (nothing really does). No particular one of these NSAIDShas been proven to give better pain relief than the others, but individuals sometimes respondbetter to a certain NSAID. Hence, your physician may try you on several of these NSAIDS in 10
  11. 11. an effort to find the one that suits you best. Periodically, new NSAIDS are introduced to themarket, often with a great fanfare of publicity. So far, none of these drugs have demonstrateddefinite superiority. Some, such as Vioxx and Bextra, have been withdrawn from the marketwhen unforeseen serious side effects occurred with widespread use. It is probably better toavoid new drugs until safety and effectiveness are well established.The three most common NSAIDS are (Advil, Nuprin, and Motrin) and naproxen. They have theadvantage of being inexpensive and available without prescription (over-the-counter drugs).Aspirin and ibuprofen both require frequent dosing. Naproxen (Aleve) has the advantage ofless frequent dosing.Most prescription NSAIDS also have the advantage of less frequent dosing but thedisadvantage of increased cost and, of course, require a prescription. All of the NSAIDScommonly cause stomach upset and have potential for other side effects such as kidney, liver,heart, and bone marrow damage. The best-tolerated form of aspirin is probably Ecotrin (acoated aspirin tablet which protects the stomach by dissolving in the small intestine). AllNSAIDS should be taken with food. Cytotec, Zantac, Tagamet, Pepcid, Nexium, Prevacid andPrilosec are sometimes given with NSAIDS to help the stomach tolerate the NSAIDS. Thesedrugs decrease the amount of acid produced by the stomach.When used in large doses for long periods, NSAIDS require periodic blood tests to detectpossible side effects. If you take NSAIDS this way, your internist or family physician shouldmonitor your NSAID intake with periodic blood tests. The side effects of NSAIDS are usuallyreversible if the problem is detected and the medication stopped in time. Your internist orfamily physician should always be notified if you are regularly taking moderate or large dosesof NSAIDS. NSAIDS can interact negatively with multiple other medications that you may alsobe taking, so always first clear NSAIDS intake with your medical physician.NSAIDS are not narcotics and are not habit forming, nor do patients develop a tolerance forthese drugs, which would make them less effective with time. Still, patients often reportdecreased effectiveness of their NSAID with time. The reason for this is that the diseaseprocess has progressed causing greater pain rather than that the patient has developed drugtolerance.Side effects of NSAIDS depend mostly on the daily dosage. Higher doses are more likely tobe effective but also are more likely to cause problems such as stomach upset and kidneydamage. In the elderly, side effects are more frequent. For these reasons Dr. Moreland rarelyrecommends NSAIDS in the usual prescription doses. He prefers low dose NSAIDS andusually recommends the over-the-counter doses of ibuprofen (Advil: up to six tablets per day)and naproxen (Aleve: up to two per day) since these low doses are effective as well as saferand more economical.The newest NSAIDS are Celebrex (celecoxib), Bextra (valdecoxib), and Vioxx (rifecoxib). Theyare from a new class of NSAIDS called COX-2 inhibitors. These new drugs were supposed tohave fewer side effects than regular NSAIDS, but did not claim to give better pain relief. Vioxxand Bextra have been taken off the market because of associated heart problems. Those whocannot tolerate the other NSAIDS may be able to tolerate Celebrex. It is more expensive thanolder NSAIDS and may cause heart problems also. Unlike the older NSAIDS, Celebrex doesnot cause increased bleeding and, thus, does not have to be stopped during the surgicalperiod. In some situations the Celebrex can be used to help with immediate postoperativepain. Recently, the FDA has warned that all NSAIDS may cause heart problems. 11
  12. 12. Acetaminophen (Tylenol) is not an NSAID. It is a pain reliever but not an anti-inflammatory. Itdoes not share with the NSAIDS their possible side effects. Pain can often be helpedsignificantly with Tylenol and patients may usually safely take six or eight a day. Large dosesof acetaminophen have occasionally been associated with liver toxicity, particularly in patientswho drink large amounts of alcohol. Acetaminophen can be used to supplement the pain reliefof the NSAIDS (acetaminophen and NSAIDS can be taken at the same time). A good over-the-counter regimen for arthritis pain is two Tylenol and two Advil with each meal. WHAT ABOUT NARCOTICS FOR HIP PAIN?Patients with sleep-disturbing hip pain can sometimes benefit from low doses of mild narcoticssuch as Tylenol (acetaminophen) with codeine (Tylenol #3), Vicodin (hydrocodone withacetaminophen), Darvocet (propoxyphene with acetaminophen), Darvon compound(propoxyphene with aspirin) and plain Darvon (propoxyphene). These drugs are habit forming,have the potential for physical and psychological dependence and, like all narcotics, lose theireffectiveness when used regularly. Thus, patients should carefully limit their intake of suchdrugs to no more than one or two a day to maintain the effectiveness and to decrease the riskof addiction. All narcotics tend to cause constipation and stool softeners can help prevent thisproblem. Low dose narcotic use at night, when sleep is disturbed by hip pain, is relativelysafe. Day use is less desirable, since mental alertness is decreased. Operating machinery ordriving a car under the influence of a narcotic should not be done.The stronger narcotics such as Percodan (oxycodone with aspirin), Percocet (oxycodone withacetaminophen), Dilaudid (hydromorphone), Oxycontin (a long acting and very highly addictivenarcotic), Demerol (meperidine) and morphine are almost never indicated for chronic hip painbecause of their strong potential for addiction. All narcotics become gradually less effectivewhen taken for long periods and thus higher and higher doses will be gradually required inorder to continue to get pain relief. The patient then will develop another problem: narcoticaddiction. If the narcotics are stopped or decreased in addicted patients, unpleasantwithdrawal symptoms will develop. In most hip pain circumstances it is better to have hipreplacement rather than to become addicted to large doses of narcotics. Dr. Morelandbelieves that some “Pain” physicians today seem too quick to give patients high doses ofpowerful narcotics for hip arthritis pain and thus create unnecessary and unpleasant addictionin their patients. The management of postoperative pain in heavily addicted patients iscomplicated, since such patients do not get pain relief with ordinary narcotic doses. WHAT ABOUT EXERCISE FOR PEOPLE WITH HIP ARTHRITIS?Patients with hip disease, like everyone, need to exercise for general cardiovascular fitness.Jogging and other exercises resulting in impact loading of the hip will probably cause anincrease in the hip pain and are usually best avoided. The best exercise to maintaincardiovascular fitness for people with hip disease is swimming, since the buoyancy of thewater minimizes the stress on the hip. Bicycling (road bikes or stationary bikes), the ellipticalmachine, and gym stair climbers are also better tolerated than running. The treadmill isintermediate in stressing the hip and many people can tolerate this since there are usuallyhandrails, but again, the exercise bicycle will probably give more cardiovascular exercise withless hip pain. After experimentation each patient usually becomes the best judge of what canbe done with an acceptable level of discomfort. 12
  13. 13. Activity is unlikely to cause deterioration of the hip to a degree that the damage cannot befixed later by hip replacement, so remain as active as your hip allows. Think of activity asirritating your hip, not as damaging your hip. Inactivity can damage the rest of your body sinceactivity is needed to properly maintain your muscles and bones, your cardiovascular systemand your mental health. WHAT ABOUT STEROID HIP INJECTIONS?Occasionally, physicians inject steroids (cortisone) directly into the hip joint to decrease theinflammation and thus the pain. It is difficult, however, to get the drug always in the hip jointcavity since the joint is deep and the capsule is tight. The process of injecting this medicinecan be uncomfortable for the patient and there is a small risk of introducing an infection.Steroid injections do not really treat the cause of the pain. They simply make the hip hurt less.Steroids do not always help the pain and the improvement is always only temporary. Becauseof these problems, Dr. Moreland does not encourage this treatment for the hip.When the patient must have temporary pain relief and surgery cannot be done for somereason, steroid injections can have a place. To insure correct placement of the steroid withmaximum safety and minimum discomfort, Dr. Moreland will arrange for a radiologist to do theinjection under x-ray control. WHAT CAUSES MY LIMP?Most patients with significant hip disease have a limp and it is common for the patient to thinkthat the reason for the limp is shortness of the extremity. Sometimes, the extremity actually isshort, but the limp is usually due to the pain. In fact, when patients limp from a painful hip theyare usually limping because it lessens the pain. The reason it hurts less is that the limping wayof walking allows the patient to contract the hip muscles with less force. This results in less hippain but causes an awkward and inefficient gait. Many patients with early hip diseaserecognize this and note that they can walk without a limp; but that doing so causes more painand that it is easier and more comfortable to limp. With time and the lack of use of certain hipmuscles, weakness results and the limp is then due to the weakness as well as the pain.Sometimes with hip disease, leg shortening occurs from the bones getting closer together asthe cartilage wears out. This slight shortening is actually helpful for the patient, since it iseasier to walk with a painful hip if that extremity is a little shorter. One way of thinking aboutthis is to realize that the short leg is walking downhill all the time and the long leg is walkinguphill. The short leg, therefore, has to put out less effort. If the short leg is the painful leg, thepatient is better off leaving the painful leg short and not using a shoe lift. If the painful leghappens to be the long leg, then shoe lifts can take some of the pressure off the painfulextremity. Dr. Moreland can advise you on the usage of lifts during your examination. WHEN SHOULD A CANE BE USED?When the symptoms worsen to a significant degree, a cane is usually very helpful to patientswith hip problems. The cane should usually be carried in the hand opposite the side that hasthe hip disease. Special platform canes may be useful for people whose hand problems limittheir ability to push on a cane. Patients with rheumatoid arthritis often have this problem. TheHorton and Converse pharmacy on the first floor of our building has a wide selection of canes.There are foldable canes that will fit in a large purse or a briefcase. The cane then can be 13
  14. 14. readily available if unexpected long distance walking is required. The cane should be the rightheight (usually such that the elbow is bent about 20 degrees) and, thus, an adjustable cane isconvenient. We can help you adjust your cane length and instruct you in its use. Mostpatients find the cane useful when going outdoors and for long walks (such as shopping malls,airports, amusement parks and foreign travel). Since the cane gives tremendous mechanicaladvantage when used in the opposite hand, just a little hand pressure will relieve a lot of hippain and control the limp. SHOULD I LOSE WEIGHT?Extra weight will aggravate hip pain. Weight loss will make you more comfortable, but isunlikely to relieve the pain completely. One pound of weight loss decreases hip stress bythree pounds, since the muscles then have to contract with less force and it is the musclecontraction that contributes to most of the hip stress. Obesity also makes surgical treatmenttechnically more difficult for the surgeon and increases the risk of surgical complications for thepatient. It is more difficult with the extra weight for patients to walk on crutches during thehealing period and to move around in bed. This increased risk is rarely of a degree to makereplacement not possible. While weight loss is desirable, we rarely insist upon weight lossbefore surgery, recognizing the well-known difficulty of weight loss, particularly whencompounded by the enforced sedentary lifestyle resulting from the hip pain. WHAT ABOUT OTHER TREATMENTS?Massage, acupuncture, acupressure, ultrasound, diet, vitamins, minerals, magnets, Chineseherbs, copper bracelets, hypnosis, TENS unit, special physical therapy techniques, watertherapy and many other treatment methods are occasionally used. At times some of these canalleviate the pain but cannot correct the basic arthritic condition. Hip pain is often episodic. Alot of activity will often cause a delayed increase in pain from the inflammation stirred up by theactivity. With rest, NSAIDS, and inactivity the pain may completely resolve for a while with orwithout other treatment. This episodic nature of hip pain often confuses patients when they tryto evaluate the effectiveness of various activities and treatments.Health food stores have marketed shark cartilage for arthritis. There are no scientific studiessupporting shark cartilage use for arthritis. Dr. Moreland has seen many patients who havetaken shark cartilage. Few have reported any benefit and Dr. Moreland does not recommendshark cartilage.By far the most popular health food store supplements for arthritis recently have beenglucosamine and chondroitin sulfate, which are usually taken together. Occasionally, patientshave reported some symptomatic relief but most patients report no effect. Definitely, we havenot seen any repair of arthritis damage or slowing of arthritis progression with use of thesepreparations and there is no good scientific evidence of such benefits. Dr. Moreland does notrecommend these health food store supplements or any others. On the other hand, worrisomeside effects have not been reported with glucosamine and chondroitin sulfate. WHEN SHOULD I HAVE MY HIP REPLACED?The decision to have a hip replacement is up to the patient. Hip replacement can commonlybe avoided as long as the patient is willing to put up with the pain and the disability. In fact,most patients, if determined, can put up with one bad hip indefinitely, since the good side can 14
  15. 15. do most of the work. Patients with deterioration of both hips often are under more pressure forsurgery, since such patients literally do not have a good leg to stand on. Since hipreplacement surgery involves some risk, expense, several months of recovery and a temporaryincrease in pain from the surgical procedure and may still not be a permanent solution, surgeryshould not be undertaken unless the symptoms are significant and persistent. If your hipdisease is so bad that you cannot get around without a wheelchair or two crutches or are evenbedridden, then most orthopedists would urge hip replacement, assuming you are physically fitenough to undertake the surgery. If you can walk without a cane or crutch for long distanceswith minimal limp or pain and do not have any sleep disturbance, your symptoms are probablynot severe enough to proceed with replacement.Most patients have their hip replaced when they experience significant and persistent pain,need a cane at least part of the time, are having sleep disturbance, and are regularly takingnon-steroidal anti-inflammatory medications (NSAIDS), assuming such drugs can be tolerated.If your hip is making life miserable, a replacement is usually a reasonable alternative to puttingup with the pain and disability. If the hip problem is only a minor and occasional bother, non-operative treatments are probably more reasonable than surgery. The decision to havesurgery should be based on information acquired from the orthopedist, the family physician,and possibly second opinions. The final decision is always the patient’s. Most patients havehip replacement when the thought of having hip replacement surgery sounds better thanputting up with the pain and disability of the arthritic hip. We hope this hip booklet will givepatients the information needed about hip replacement to make that decision. There is almostnever any urgency for replacement of the hip unless the pain is severe.Patients who have only one painful and stiff hip can usually get by with a sedentary lifestyle byavoiding airports, amusement parks, malls, and travel. The desire to have a more activelifestyle can force surgery at an earlier stage. Many patients find that just at retirement agewhen they finally have the time to travel and enjoy the world, an arthritic hip can make theseactivities difficult, if not impossible. With a hip replacement the patient’s world can beexpanded and the retirement years can be more active.Since introduced in the United States about 1969, hip replacement has gradually beenimproved. In the early years there were problems with short term complications, long termdurability, and a long and uncomfortable recovery period. On all three issues there has beentremendous progress. Today in the hands of an expert surgeon operating in a good hospitalwith competent medical personnel, patients should expect extremely high short term successrates as well as a shorter and more comfortable recovery period. Modern prostheses promisedurability that probably will exceed most patients’ life span. Durability has been so increasedthat patients now are given almost no activity limitations. Patients with modern hipreplacements can do many very vigorous activities such as tennis, skiing, volleyball, handball,racquetball, etc. with little increased risk to the longevity of their hip replacements. Hipreplacement today is truly a medical miracle. CAN I PUT OFF SURGERY?There are some advantages to putting off surgery. Progress in hip replacement surgerycontinues. Thus, if you wait five to ten years, the technology available should be better thanwhat we have currently. If you wait, you will get older and thus need the replaced hip for ashorter period of time. This is important since the major problem with hip replacements hasbeen durability, since loosening and wear occur occasionally. That said, the technology of hip 15
  16. 16. replacement today is so advanced that there is little reason to wait for further improvements.Hip replacement is one of the best, if not the best, elective operations surgeons have to offer.The disadvantages of waiting are the discomfort and disability, the possible loss of muscle andbone strength from inactivity and the decreased mental and physical vigor from the disease-enforced low activity lifestyle.Do not worry that the hip deterioration will get so bad that it cannot be fixed or the chances ofsurgical success will be less later. Such deterioration rarely occurs. Do not worry that you willdamage the other surrounding joints (such as your back, knees, or other hip). While the extrastress on these joints may irritate these areas, it is unlikely damage will occur. Also do notworry you will get too old or too sick to have surgery later. It is very rare for a patient whoneeds surgery to be too old or too sick to have it done. If you are too sick, usually you are soinactive that surgery is not needed. The only valid reason to have hip replacement is a hip thatis giving you persistent and significant pain and disability resulting in a miserable lifestyle. ARE THERE OTHER SURGICAL TREATMENT ALTERNATIVES?Hip disease can be treated by other surgical methods besides hip replacement. Onealternative is hip fusion (arthrodesis). This is a procedure in which the femoral bone is made toattach to the pelvic bone resulting in permanent and complete stiffness of the hip joint. Thelost mobility of the fused extremity is partially compensated for by the mobility of the spine andthe knee. Arthrodesis is rarely performed today because most patients will not accept this hipstiffness. It makes both sitting and standing awkward, and activities involving reaching downto the foot are quite difficult. Occasionally, hip fusion is recommended for young people whoneed to do vigorous labor. Because a stiff hip puts extra stress on the spine and the knee, it iscommon for patients to develop pain and arthritis in these joints as the result of a stiff hip. Oneconcept is to eventually do a hip replacement for a fused hip when the patient is older. Thisproblem of extra stress on the spine and the knee requires the patient to have a normal spine,normal knees and a normal hip on the other side for a hip fusion to be seriously considered.Hip fusion is very rarely done today.Another alternative is termed osteotomy of the pelvic or femoral bone. An osteotomy is aprocedure in which the bone of the femur or the pelvis, or both, is cut, and the bones are thenplaced in a new and different position and then the bones are allowed to heal in this newposition. This results in a redirection of the hip forces in a new and, it is hoped, less painfuland more durable direction. Osteotomies of the hip are much more popular in Europe than inAmerica. Osteotomies require longer recuperation and the results are less predictable thanhip replacement. Patients with shallow sockets from DDH (developmental dysplasia of the hip)are often candidates for this operation but the improved reliability of hip replacement today hasdecreased the need for this operation. WHAT IS THE HISTORY OF HIP REPLACEMENT SURGERY?In 1962 Sir John Charnley, an English orthopedist who was knighted by the Queen of Englandfor his hip replacement contributions, put together the key ingredients of the modern hipreplacement. Charnley’s operation involves removal of the bony femoral head and replacingthis with a smaller metal ball which is attached to a stem which fits into the femur (the thighbone). The femur is basically hollow in its mid-portion and ordinarily there is some bonemarrow in this area. This hollow area is where the stem of the prosthesis is placed. The bone 16
  17. 17. marrow that is removed from that area is not needed. The prosthesis itself must be fixed to thefemur, since movement between the prosthesis and the bone causes pain. In Charnley’soperation it is fixed with plastic cement called methylmethacrylate, which is the same chemicalcompound as Plexiglass and was first developed for human use by dentists. The bony socketsurface is also replaced by a plastic socket fixed into place in the bony socket, also with themethylmethacrylate cement. This cement acts as a grout similar to tile grout and should not beconsidered glue. Cement comes unmixed with powder and liquid components which aremixed together until a dough-like consistency is reached. This dough is then pressed into thebone and the prosthesis is pressed into the dough. The cement then hardens over ten tofifteen minutes into a stone-like consistency. After the hip replacement is assembled, themetal ball will move around in the plastic socket and transmit the force across the hip joint.Since the femoral bone is no longer rubbing on the pelvic bone, the patient gets pain relief.The plastic socket is made of ultra-high molecular weight polyethylene, which has littlefrictional resistance against the metal ball.Wear of hip replacements has always been a problem. In the 1950’s Charnley used Teflon asthe plastic in his hip replacements and had great short term success, only to be disappointedwhen many operations failed because of rapid wear of the Teflon. The modern era of hipreplacement dates to 1962 when Charnley started using ultra-high molecular weightpolyethylene which has a dramatically lower wear rate than Teflon. See the section entitled “ISWEAR A PROBLEM?” on page 25 for more information on wear.Charnley-type total hip replacements were introduced in the United States about 1969. Hipreplacement operations have become routine (over 300,000 hip replacements are done in theU.S. annually) and are considered successful a very high percentage of the time.. WHY IS IT CALLED A TOTAL HIP REPLACEMENT?The term total hip replacement is commonly used by orthopedists but is actually not a goodname for the procedure, since it sounds more radical than the actual operation. A joint is anarea of the body where two bones come together. Orthopedists refer to each bone as being aseparate side of the joint. Thus, the hip joint has the acetabular side and the femoral headside. Surgery done on only one of the two bones, leaving the other bone unchanged, is calleda hemiarthroplasty. Hemi means half and arthroplasty means an operation to make a jointbetter. Hemiarthroplasties of the hip are commonly done for patients with fractures of the hip.The hip usually breaks just below the ball or head of the femur in the narrowed area of thebone called the neck of the femur. Since fractures of that area commonly disrupt the bloodsupply to the femoral ball, surgeons often replace the bony ball with a large metal ball that isattached to a stem fixed inside the femoral canal often with cement. The acetabular bone isactually not changed in this operation. The big metal ball is large enough and of theappropriate size to fit in the original bony acetabulum.When hip replacements began to be done and both bones were operated on, the term total hipreplacement was coined and has come into common usage in the United States. In fact,Charnley referred to his operation as the low friction arthroplasty and in England a hipreplacement is still referred to as a low friction arthroplasty. Charnley liked this term, since itwas his original concept that hip replacements should have low friction. He felt, and wasprobably right, that a small ball rubbing around in a polyethylene socket gave low frictionalresistance and that this was critically important for the hip to do well. 17
  18. 18. Since hip fractures are very common, many thousands of hemiarthroplasties are performed forhip fractures. The hemiarthroplasty operation takes less time than a total hip replacement andhas less blood loss. Patients with a broken hip have extreme pain but with a hemiarthroplastyare usually able to get out of bed and resume their daily functions. On the other hand, thepain relief from hemiarthroplasties is often less complete and less consistent than one getswith a total hip replacement. Patients with pain from a hemiarthroplasty usually have pain inthe groin associated with activity. If patients have persistent and significant pain, some mayrequire conversion to a total hip replacement. WHAT ARE THE PROBLEMS WITH CEMENTED HIP REPLACEMENT?The major long-term problem with the Charnley type cemented hip replacement is the potentialfor development of loosening of the attachment of the plastic cement to the bone. Withloosening, the prosthesis then moves in a gradually increasing degree with respect to thebone. This movement causes irritation to the bone, can cause bone loss, and results in a painsimilar to pain with an arthritic hip. Pain from an arthritic hip is caused by the bone-on-bonecontact. What a hip replacement does is keep the bones from touching, with the movementoccurring only between the two pieces of the hip replacement: the ball moving around in thesocket. The key to making a hip replacement painless is no movement of the hip replacementcomponents with respect to the bone. The components themselves must be securely fixed tothe bone. If there is movement between the component and the bone, irritation of the bonewill occur with resultant pain.If the pain or bone loss from loosening is severe, a second surgery may be necessary, usuallyreferred to as revision surgery. The precipitating reason to proceed with revision surgery of aloose hip replacement is almost always a degree of pain and disability sufficient that thepatient and the surgeon think that revisional surgery is indicated. Many patients have minordegrees of loosening determined by various findings on their radiographs but have minimalsymptomatology and thus do not need a revisional surgery. As the prosthesis loosens, there iscommonly damage to the bone. We are very protective of the bone in the area of a hip sincethe bone quality is a strong determinant affecting the surgeon’s ability to place a new hipreplacement if necessary. If the bones are of poor quality, the surgeon may have difficultygetting a new prosthesis fixed to the bone and in rare cases it is not possible to do so. Somepatients have x-ray changes of severe bone loss but few symptoms. Occasionally, we adviserevisional surgery for such situations, particularly in active patients with long life expectancies. ARE THERE MORE DURABLE ALTERNATIVES?Surgeons have continually tried to develop techniques which will lower the loosening rate andalso give the same excellent pain relief and function of a Charnley type (cemented) hipreplacement. A well proven alternative now is to use a prosthesis which has a surface intowhich or onto which bone can attach and permanently bond the prosthesis to the bone. Forthis technique the methylmethacrylate cement is not used. This is called a cementless hipreplacement. The first cementless hip replacements allowing bone attachment had poroussurfaces or are referred to as porous hip replacements. The innovators of this cementlessconcept began using porous prostheses in the United States about 1978. Several researchersin France such as Judet and Lord began even before that. Today there are multiple types ofcementless hip replacements available in the United States. The oldest one in continuous 18
  19. 19. usage in the United States is the AML hip replacement manufactured by DePuy in Warsaw,Indiana. This device was first used by its innovators in 1978 and is a porous total hip that hasbeen used by Dr. Moreland for many years. About 1983, as the concept of cementlessreplacement became popular with surgeons and patients, many other types of porous hipreplacements were introduced in the United States. Some of these have stood the test of timeand some have not. The reported results of various types of porous hip replacements havevaried greatly depending upon the particular device used, the skill of the surgeons, and thepatient population treated. Many designs have been discontinued or greatly modified. Some(such as the AML) have stood the test of time and are still widely used.There are now also many successful hip replacements with surfaces that allow boneattachment but do not have a porous surface. Some just have a surface roughness that allowsconsistent bone attachment. Some are covered with a material similar to bone calledhydroxyapatite which further promotes bone attachment. WHAT ARE THE PROBLEMS WITH CEMENTLESS HIP REPLACEMENTS?First of all, we should recognize that there is a great difference in the design of the variouscementless hip replacements. There is also a great difference in the design of the variouscemented hip replacements. Today, the original Charnley hip prosthesis is used relativelyinfrequently in the United States, although it is still considered a well-designed prosthesis.Many other designs of cemented prostheses have been introduced to the U.S. market sincethe Charnley replacement came into wide use almost thirty-five years ago. Many of thesenewer cemented hip replacements have proven with time to have higher rates of looseningand other problems compared to the original Charnley prosthesis. As these prostheses havebeen proven to have inferior results compared to the Charnley, their use has been abandoned.As mentioned, a similar situation exists with cementless replacements. The AML is acementless prosthesis that has stood the test of time but there are now other good cementlesship replacements on the market. The AML has one of the longest track records with goodresults. There are many cemented hip replacements also with good track records and incommon use in the United States.Problems with the cementless hip replacements have been the occasional lack of bonyattachment, fracture of the bone on insertion and incomplete pain relief. When mostcementless hip series are compared to the best cemented hip series, the cementless hipshave shown a slightly higher rate of pain. On the other hand, if you compare some cementlesship replacement results against some of the cemented stems of inferior designs, thecementless replacements look better. The important thing is to compare well done (since theresults of surgery varies greatly with respect to the quality of the initial surgery) cemented hipreplacement with a good prosthesis with well done cementless hip replacements withprosthesis of a recognized good design. Such direct comparisons are not readily availablebecause of many difficult to control variables. Still, it is Dr. Moreland’s assessment that if youcompare a large group of well done cemented hip replacements with a good prosthesis to alarge group of well done cementless hip replacements using a good prosthesis, the pain reliefon average, particularly in the first one to two years, would be slightly less complete and lessconsistent with the cementless prosthesis. There would be some patients in the cementedgroup with some aches and pains but more patients in the cementless group with aches andpains. By about one to two years after surgery the pain relief for the two groups is very similar.The rationale behind the cementless replacement being utilized despite this slightly inferior 19
  20. 20. early pain relief is that a more vigorous lifestyle is possible since the cementless bond to thebone is sturdier than the bond of the cement to the bone. There is much less apprehensionand fear of failure for a patient to do such things as playing tennis and snow skiing and othervigorous activities than there is with a cemented implant.The bond in the cemented hip replacement is at its maximum shortly after the operation isdone. The bond of the cementless prosthesis to the bone initially is only via a press-fit inwhich the prosthesis is simply driven into the bone as a nail is into a piece of wood with aninterference fit. Over the next one to two years the bone attaches itself to the prosthesis. Thefemur itself must gradually accommodate and change in response to the different stresses thatare now being applied to the inside of the bone. During this time some patients have someaches and pains usually manifested by feelings of discomfort in the thigh. An occasionalpatient has significant problems. These problems, however, are almost always transitory andof a relatively minor nature and resolve with time as the bone changes in response to theprosthesis.Just as cemented prostheses can get loose, a cementless prosthesis that does not get bonyingrowth may also get loose as the initial interference fit is gradually overcome by the forcesplaced on the prosthesis. This lack of bone fixation to the implant rarely occurs in first time hipreplacements and occurs more often in patients with poor bone quality. Most of the patientswho do not achieve bone attachment have more aches and pains than patients who doachieve bone attachment but most still have less pain than before surgery and are happyenough with the pain relief not to need additional surgery. In fact, Dr. Moreland has beenperforming the AML type cementless hip replacement since 1984 and has done over 3,400 ofthese replacements for patients with hip arthritis. Only 15 (0.4%) patients so far have had tohave a revisional surgery for a component that did not achieve bony ingrowth in first time hipreplacement. With some other implants, surgeons have reported higher rates of theprostheses not achieving bone ingrowth and requiring further surgery. No documented casesof loss of the bony ingrowth have been found, once the AML prosthesis has become ingrown.The cemented hip replacement’s main advantage is consistent, complete and early pain reliefbut with problems with late loosening. The cementless hip replacement’s main advantage isincreased durability to vigorous activities but with the possibility of more aches and pains,particularly in the early postoperative period. One should not label cemented and cementlessreplacements as good or bad. In reality, both types of fixation of the prosthesis to the bonework very well in the hands of a good surgeon and with a well-designed prosthesis. Badprosthetic designs of both types, particularly in the hands of less skilled surgeons, will givehigh failure rates.Surgeons have learned over several decades of hip replacement that different patients havedifferent demands, and hence, both cemented and cementless hip replacements are beingused with the cementless technique increasingly dominating the market. In fact, cementedreplacements now have a small part of the U.S. market and even that portion is declining. Dr.Moreland almost always uses cementless hip replacements WHAT DETERMINES CHOICE OF TYPE OF FIXATION?The most important determining factors with respect to choice of type of replacement are thequality of the bone, the patient’s life expectancy, and the patient’s expected activity level.Many patients develop osteoporosis for various reasons. Bone is not a solid structure, butinstead has small holes in it similar to a sponge. The more holes there are and the larger the 20
  21. 21. holes, the more porotic the bone and the less strong the bone. As we grow older, all of ushave skeletons which are becoming more porotic or osteoporotic. Patients with low activitylevels do not stimulate their skeleton to be strong and often develop osteoporosis. People withlow calcium and vitamin D intake and other metabolic deficiencies will develop osteoporosis.Lighter skinned people have a greater tendency to develop osteoporosis than darker skinnedpeople do. Women as a group have a higher propensity to osteoporosis, which seems toaccelerate after menopause. Thus, lighter skinned women after menopause are at particularrisk for osteoporosis.Osteoporosis can be treated in various ways but treatments are mainly directed againstminimizing further bone loss. All of us should have an adequate calcium intake in our diet andif you do not, calcium supplements should be taken. Some women after menopause takeestrogen for a variety of reasons, one of which is to maintain bone strength. One can detectosteoporosis by a variety of techniques but usually a reasonable assessment of the quality ofthe bones can be made simply by a review of the hip x-rays. Dr. Moreland can tell youwhether you have significant osteoporosis and if so, further consultation and treatment for thiswith the appropriate specialist can be arranged.Cementless implants do not work as well for patients with severe osteoporosis as for thosewith strong bones. Older patients, patients with severely osteoporotic bones, and patients witha limited life expectancy may be well served by a cemented implant. Sometimes the pros andcons of the two different types of replacements sum up to a situation where patient andsurgeon can simply choose either operation and achieve a similar high degree of success.Many surgeons believe that patients with severe osteoporosis do better with a cementedfemoral implant, but the failure rate of cemented hip replacement is also higher in patients withsevere osteoporosis. Even in patients with significant osteoporosis, Dr. Moreland usuallyprefers cementless hip replacements.Patients with a very active lifestyle, such as those who play tennis and snow ski and do othervigorous activities are much better served by a cementless replacement, which has a betterchance of standing up to such activities than would a cemented hip replacement. There aremany patients in their seventies and even eighties still doing very vigorous activities, such asplaying tennis, and who usually have excellent bones. These patients are certainly betterserved with a cementless implant. Young patients are almost always advised to have a porouship replacement, since they will likely benefit from the increased durability. WHAT ABOUT THE HYBRID HIP REPLACEMENT?Hybrid hip replacement is the term used to describe a hip replacement in which onecomponent is fixed with cement and the other is not. Currently, surgeons almost always useporous (cementless) acetabular (socket) components since it is generally agreed that they aremore durable and give the same pain relief. The controversy is mainly over cement versuscementless for the femoral stem component. Patients receiving a cemented femoralcomponent with a cementless acetabular component are said to have had a hybrid hipreplacement. This hybrid concept was more popular 5 to 10 years ago than now. Todaycompletely cementless hip replacements are much more popular than the hybrid hipreplacements. SHOULD THE PATIENT DECIDE IMPLANT TYPE? 21
  22. 22. How well a patient does with a hip replacement depends upon a variety of factors. One factoris prosthetic choice, but the choice of the surgeon and the hospital with its support personneland facilities are very important factors. In fact, the most important factor is how well thesurgery is technically done. The skill of the surgeon is overwhelmingly the most importantfactor as to how well the patient does. While it is interesting and important to discuss types ofprostheses used and various surgical techniques, patients really should concentrate more onmaking sure that they have selected a good surgeon and allow that surgeon to do theoperation in a way with which the surgeon is most confident and familiar. When arrangingpiano music for a party, you would probably spend more time evaluating the pianist thanselecting the piano. A good pianist can get music from a bad piano and a poor pianist cannotget music from the world’s best piano. Surgery is similar. There are many surgeons withexcellent skills and experience with hip replacement and Dr. Moreland would be happy to helpyou locate a good surgeon in your area, if travel to our area is a problem or for any otherreason. WHAT ABOUT SURFACE REPLACEMENT?Before Charnley’s hip replacement was first used in the U.S. around 1969, the most commonoperation for hip arthritis was the cup arthroplasty. In this relatively simple operation, a thinmetal cup was placed over the femoral head after some bone shaping. The metal cup coveredhead was simply placed back in the bony socket (acetabulum). No cement was used toanchor the cup to the femur. When Charnley’s operation proved its dramatic superiority, thecup arthroplasty operation was quickly discarded with the approval of cement by the Food andDrug Administration (FDA) around 1970. Later, when loosening developed in some patientswith Charnley’s operation (particularly in the young, big and active patients), several centersworldwide began using an operation which combined elements of the old cup arthroplasty withelements of Charnley’s operation. The centers were UCLA (Amstutz), Indianapolis (Capello),Michigan (Townley), England (Freeman), Germany (Wagner), Japan, and Italy. In the late1970’s this operation (termed surface replacement in the U.S.) was used widely around theworld. Similar to the cup arthroplasty, the femoral head was maintained rather than beingremoved as in a Charnley type replacement. A metal shell was placed over the femoral head,as in the cup arthroplasty, but in this operation it was cemented in place with the samemethylmethacrylate cement used in the Charnley operation. A thin plastic socket made out ofpolyethylene was also cemented in the bony socket. Since both sides of the hip werereplaced, this was considered a type of total hip replacement. Surgeons worldwide werehopeful surface replacement would be more durable than Charnley’s operation. By the early1980’s multiple centers reported results, not better than the Charnley operation, but muchworse. Surface replacement of the hip was then rarely used for many years.Some investigators continued to work on experimental variations of operations in which thefemoral head is maintained instead of being removed (an intuitively attractive concept) butunacceptable rates of failure continued for several surgical variations of surface replacement.Most authorities believe that the inherent thinness of the polyethylene in surface replacement(thin polyethylene has a high wear rate) was the Achilles heel of surface replacement.Metal-on-metal (no polyethylene at all) surface replacements are now being used in the UnitedStates. This operation has received FDA approval but is not covered by all insurance plans. Arecent report in the orthopedic journal “The Journal of Bone and Joint Surgery” (JBJS)documented a worrisome early failure rate from femoral loosening and femoral neck fracture inpatients given experimental metal-on-metal surface replacements. This article was published in 22
  23. 23. January, 2004 in volume 86-A. In that series of 400 metal-on-metal surface replacements donebetween November, 1996 and November, 2000, 17 hips (4.3%) had already requiredreoperations, mostly for femoral loosening or fracture of the femoral neck and another patienthad known failure when last seen. Dr. Moreland has reviewed his patients having cementlesstotal hips during that same November, 1996 to November, 2000 time frame. There were 859cementless total hips done during that period with only 8 hips (0.9%) requiring reoperations sofar. Please see more detailed hip replacement data on pages 46 and 47 of this booklet.Metal-on-metal surface replacements produce huge numbers of submicroscopic metalparticles. Some of the metal goes into solution and high levels of metal ions in the blood andurine have been measured in patients with metal-on-metal surface replacements. There isconcern that these metal ions could cause cancer or other metabolic abnormalities. There isparticular concern about the safety of metal-on-metal hip replacements in women who maylater have children, since the fetus would be exposed to these metal ions, and in patients withrenal disease, since some of the metal ions are excreted by the kidneys. There have also beenreports from Europe with metal-on-metal hip replacements of pain from metal allergy requiringrevision to metal on plastic in order to relieve the pain.Surface replacement of the hip has been heavily promoted on the internet. Young, athleticpeople with hip arthritis have been attracted to the metal-on-metal surface replacementconcept. As stated, it is intuitively attractive and there have been claims by some that metal-on-metal surface replacements allow a higher level of function for these high activityindividuals. There is no scientific support for this claim. Once a cementless stem type hipreplacement has fully healed, Dr. Moreland places no activity restrictions on the patient.Patients with successful cementless stem type hip replacements can be just as active as thosepatients with surface replacements. Surface hip replacements have a known risk of femoralneck fracture. Dr. Moreland believes there is more risk of failure with vigorous activities withthe surface replacement than with a stem type replacement because of concern about femoralneck fracture. Well-controlled and long-term studies are needed to determine what is best butmost reports available so far show a higher rate of failure with the surface replacement. WHAT ABOUT OTHER NEW TECHNIQUES?Periodically, new implants and surgical techniques are introduced to the orthopedic and laycommunity with great fanfare and claims of superiority to older techniques. In hip replacementsurgery we already have well-established techniques (e.g. Charnley’s operation) that quiteconsistently and reliably give excellent pain relief and function. What has been lacking is anability to give all patients (especially the young, big and active patient) a hip replacement whichwill reliably last the rest of the patient’s life. Thus, any new technique or implant can add to thestate of the art of hip replacement only by proving to be more durable. Durability can only betested by human implantation and long-term observation. Thus, all new techniques andimplants do not automatically represent improvements. The words “new and improved” gohand in hand in most new product introductions such as cars, cell phones, computers, etc. andwe almost treat the words “new and improved” as synonyms. In hip replacement “new” and“improved” are definitely not synonyms but instead “new” really equals unproved, or evenharsher, experimental. Remember that Charnley did the first modern hip replacement only in1962 and we began hip replacement in the United States only in about 1969. If a patient’s lifeexpectancy is many decades, most types of hip replacement for that patient should beconsidered experimental procedures for that patient, since virtually all hip prostheses incommon use today have usage history less than the life expectancy of such a patient. 23
  24. 24. The media, in an effort to increase viewership and thus revenue, often report various newhealth developments in an exaggerated way and, thus, often falsely and cruelly raise thehopes of patients. Some hospitals and some surgeons pay the media to report their supposeddramatic advances in hip replacement surgery in a shameless attempt to attract more patients.The media seems at times to try purposefully to disguise advertising copy as a scientific report,making it difficult to differentiate reports of real scientific advances from simple advertising.Many promising new techniques, such as surface replacement (described above), custom hipreplacements, the Mittelmeir hip (the original ceramic-on-ceramic hip developed in Austria andintroduced many years ago and later taken off the market because of a high failure rate),custom hip prostheses made during surgery, “improved” polyethylene formulations and thethreaded acetabular component have with time proved to be big steps backward and not stepsforward.Hip replacement using a robot and hip replacement with computer guided navigationalsystems have received media attention. Neither the necessity nor practicality of theseexperimental techniques has been proven and cannot be proven for many years despite theglowingly positive media reports propagated by their enthusiasts.Hip arthroscopy (similar to the widely used knee arthroscopy) has little place in the treatment ofhip arthritis. Some surgeons use the lure of a “simple” hip arthroscopy in a “bait-and-switch”way to attract patients. Hip arthroscopy is not a simple procedure like knee arthroscopy andhas a significant risk of complications. As opposed to the knee, the hip is a deep structure anddoes not have a spacious joint cavity into which an arthroscope can be easily inserted. Theleg must be pulled forcibly to distract the femur away from the acetabulum so that thearthroscope can be inserted. Damage to the hip articular cartilage can be done by thearthroscope itself in this process. Also importantly, there is actually very little that anarthroscopist can do to help a patient with hip arthritis.Be wary of self-proclaimed “Institutes or Centers of Excellence in Hip Replacement” withoutwell-established community recognized expertise. There are, unfortunately, no requirementsfor the use of the terms “institute” and “center”. Many institutes are truly substantial, but someconsist only of glossy brochures, an advertising agency, and a phone answering servicerelaying referrals to physicians without particular extra expertise.Dr. Moreland has prepared a report of the results of his primary hip replacements on pages 46and 47 of this booklet. This data may be useful to patients seeking to compare the results ofone surgeon with another. When making comparisons, it is not enough only to know incisionlengths, predictions of rapid recovery and early discharge, and undocumented claims of being“better”. Patients should also compare surgeon hip replacement volume, infection rates,dislocation rates, loosening rates, reoperation rates, perioperative death rates, nerve (femoral,peroneal, posterior tibial, and anterior femoral cutaneous) damage rates, femoral fracturerates, blood clot rates, leg length discrepancy rates, vascular damage rates and heterotopicbone formation rates. WHAT ARE THE SOME COMPLICATIONS OF HIP REPLACEMENT?Hip replacement is very successful and complications are uncommon. There is easily a greaterthan 95% chance that the replacement can be accomplished without serious complications.The most devastating complication is infection. The chances of an infection in a first timeoperation are one out of several hundred. Infection can be introduced into the hip joint at the 24
  25. 25. time of surgery when the wound is open, since there are always bacteria in the air and on thepatient’s skin. Precautions are taken against this occurring by using special operating roomswith extra clean air (laminar flow rooms) and by giving prophylactic antibiotics. Infection alsocan be introduced into the hip by way of the bloodstream at any time after the surgery.Although unlikely, infections in other parts of the body can spread to the hip replacement.Dental work also can release bacteria into the bloodstream which then can travel to a hipreplacement and cause an infection. Thus, patients with hip replacements may need to takeprophylactic antibiotics by mouth shortly before and after some dental work and before othermedical procedures which can cause bacteria in the bloodstream. Before any medical ordental procedures, a patient with a hip replacement should always remind the treatingphysician or dentist that the patient has a hip replacement. Responsibility for givingprophylactic antibiotics is that of the physician or dentist performing the medical procedure.Hip replacement patients should have any bacterial infections, other than those of the hipreplacement itself, treated promptly by their primary care physician. Viral infections, such ascolds, and fungal infections of the skin or nails are not a threat to a hip replacement.Loosening of the fixation of the prosthesis to the bone, as has already been mentioned, is amajor long-term problem with cemented hip replacements. The durability of a cemented hipreplacement is determined by three factors. The skill of the surgeon is the first and mostimportant factor. If the surgery is done well, it will last much longer than if it is done poorly.The second factor is the stress the prosthesis will have to withstand. This is dictated by thepatient’s activity level. Vigorous activities such as running and heavy lifting cause stress to bedelivered to the prosthesis and can cause it to become loose. Thus, patients with cementedhip replacements should avoid stressful activities. Cemented hip replacement patients canparticipate in golf, swimming and bicycle riding but should avoid other more stressful activities.The third factor affecting the rate of loosening is the condition of the individual patient’s bonessince some bones are formed in a way that makes it difficult to get the replacement well fixed.In contrast, once bony ingrowth has been achieved, cementless porous-coated hipreplacements have an almost zero chance of loosening, even with the most stressful activities. IS WEAR A PROBLEM?Wear of the ultra-high molecular weight polyethylene socket had been considered for a longtime a minimal problem. In the 1950’s Charnley experimented with Teflon as the plastic for hissocket and was disappointed to find high rates of failure because of wear. With hisintroduction of the ultra-high molecular weight polyethylene beginning in 1962, wear becamemuch less of a problem and during the 1970’s and 1980’s attention was focused on ways toimprove fixation of the implant. With the improved fixation of an ingrown porous hipreplacement and increased activity levels of the patients, surgeons found that the durability ofthe prosthetic fixation often exceeded the wear potential of the polyethylene. There is someevidence to suggest that wear of the plastic is increased with the cementless devices but thereare many other factors possibly affecting wear (activity level, plastic quality, ball quality, ballsize, cup design, stem design, and the type of metal).Cobalt-chrome alloy balls create much less wear on the plastic than titanium alloy balls whichare no longer used. Ceramic balls also can be used to articulate against the polyethylene.Ceramic has the advantage of being very hard and thus very difficult to scratch and can bepolished to a high degree. Ceramic has the disadvantages of possible fracture (extremely rarewith modern designs) and increased cost. 25
  26. 26. Wear is a problem from two standpoints. The ball can wear its way all the way through theplastic and start to hit the metal shell and cause catastrophic problems. This actually rarelyoccurs with today’s modern designs but did occur occasionally with some earlier designs whichhad a thin layer of polyethylene. The problem today is bone loss which can occur from thewear particles themselves. The body’s tissues can react to the tiny microscopic wear particlesin a way that destroys bone. Most likely the body confuses these tiny wear particles withbacteria and in an effort to clear these particles from the hip, the body’s tissues reabsorb someof the bone. Patients will not necessarily have symptoms from wear until very late in the wearprocess. Thus, patients should be followed by their orthopedist with x-rays every two or threeyears to look for evidence of wear and possible bone destruction from the wear particles. Theplastic lining of the cup and the ball of the stem can usually be relatively easily changedwithout disturbing the cemented or bone ingrown surfaces of the implant. A reoperation forwear is usually a much easier one than a reoperation for loosening.Wear has been the most frequent cause of reoperations at most hip replacement centers inrecent years. Fortunately, significant progress in wear reduction has been made. Severalresearchers working in different centers have developed a new manufacturing process for thepolyethylene which increases the cross-linking of the long chain polyethylene molecule andlowers the laboratory wear rate of the plastic to practically zero. Dr. Moreland has been usingthis highly cross-linked polyethylene formulation routinely since September 1999 and so farvirtually no wear has been found in these patients. Thus, the clinical results are corroboratingthe wear testing in the laboratory. Even in young patients, we now have the potential for life-long hip replacement durability. It is a gratifying time for both hip replacement candidates andhip replacement surgeons.Metal-on-metal hip replacements are also being used but have the disadvantage of metal ionrelease into the blood. Metal-on-metal hip replacements produce huge numbers ofsubmicroscopic metal particles. Some of the metal goes into solution and high levels of metalions in the blood and urine have been measured in patients with metal-on-metal hipreplacements. There is concern that these metal ions could cause cancer or other metabolicabnormalities. There is particular concern about the safety of metal-on-metal hip replacementsin women who may later have children, since the fetus would be exposed to these metal ions,and in patients with renal disease, since some of the metal ions are excreted by the kidneys.There have also been reports from Europe with metal-on-metal hip replacements of pain frommetal allergy requiring revision to metal on plastic in order to relieve the pain.Ceramic-on-ceramic hip replacements have been reintroduced in the U.S. with a lot ofadvertising by some manufacturers, one of which has used the golfer, Jack Nicklaus, as a paidspokesman. Jack probably would be a good source for advice about putters, but his adviceabout prosthetic choice in hip replacement is suspect. An earlier version ceramic-on-ceramichip replacement introduced with similar great fanfare about 15 years ago (the Mittelmeir) wastaken off the market completely a few years later because of a high failure rate. A serious butinfrequent problem with ceramic-on-ceramic hip replacement is fracture of the ceramic itself.This weak material can and has fractured. In addition, there are now frequent reports ofbothersome squeaking sounds coming from ceramic-on-ceramic hip replacements.Today we have three relatively new developments in hip replacement to address the wearproblem: highly cross-linked polyethylene, metal-on-metal articulations, and ceramic-on-ceramic articulations. All look quite good since short term data and laboratory testing showmuch less wear than earlier technology. All three have their advocates but there is actually nodata to prove that one of these three is to be preferred. 26
  27. 27. WHAT ABOUT HIP REPLACEMENT DISLOCATION AND SURGICAL APPROACH?Dislocation of hip replacements (the metal ball coming out of the plastic socket) occursinfrequently. The metal ball is held into the plastic socket by muscle tension and, after the hipmaturely heals, by scar tissue. Thus, patients with poor muscles are more likely to sufferdislocation. During the first few weeks after surgery, before scar forms around the metal balland before muscle strength returns, the hip is more likely to dislocate. During this timeavoidance of certain positions may help to decrease the rate of dislocation. The physicaltherapist can teach you the positions to avoid and how to use your hip replacement safely inthe first few weeks after surgery. If the hip does dislocate, it is usually a relatively simplematter after sedation in the emergency room for the surgeon to pull on the extremity and thehip will pop back into place. Dislocations most commonly occur in the first few weeks aftersurgery, but occasionally patients develop repetitive dislocations requiring corrective surgery.The postoperative dislocation rate varies with the skill of the surgeon, the surgical approachchosen by the surgeon, the size of the ball used and the patient population served. The usualdislocation rate reported in the literature in first time (primary) hip replacement is about 3%. Dr.Moreland’s primary dislocation rate is around 0.4% or about one-eighth of the usual rate.Dislocation is a significant complication, since a dislocation is painful and causes the patient tolose faith in the replacement which can be a significant psychological burden.Several different surgical approaches can be used to obtain the exposure needed to put in ahip replacement. Hip replacements are done with a variety of approaches. Surgicalapproaches can be broadly divided as to whether the hip joint is entered by going anterior (infront of) or posterior (behind) the top end of the femur (thigh bone).. The hip replacementliterature has repetitively documented a much lower dislocation rate for the anteriorapproaches compared to the rate with the posterior approaches. Dr. Moreland has used ananterior approach since 1992 because of the low dislocation rate.Sir John Charnley strongly advocated the transtrochanteric approach. This approach involvesthe temporary removal of the greater trochanter with it being replaced at the end of thesurgery. This approach gives the best view of the hip but is very rarely used today because itrequires the use of wires and has the risk of wire breakage and lack of trochanteric bonehealing. Rarely (less than one case out of a hundred) Dr. Moreland uses the originaltrochanteric removal approach in difficult and complex cases because of its better exposure.Dr. Moreland stopped using this approach routinely many years ago, as did almost all othersurgeons, because its disadvantages outweighed its advantages in the usual primaryreplacement.Anterior approaches can be subdivided into two types. The two differ as to whether the hip isapproached anterior (Smith Peterson approach) or posterior (Watson Jones approach) to thetensor fascia lata muscle. These are both old approaches having been described by twofamous early 20th century English surgeons. The Watson Jones approach (a version of whichDr. Moreland has used for 15 years) has been until recently practically the only type of anteriorapproach used in the United States. The Smith Peterson type of anterior approach has beenadvocated by several surgeons in recent years. Both of these anterior approaches have lowdislocation rates.As mentioned, the head size of the femoral component affects dislocation rates. Larger headsare less likely to dislocate and thus Dr. Moreland today uses heads as large as is practical,limited by technical considerations of prosthetic design. 27
  28. 28. WHAT ABOUT OTHER POSSIBLE COMPLICATIONS?Nerve damage occurs less than 0.1% of the time with a hip replacement. The nerve mostcommonly damaged is the nerve to the muscles which bring the foot up toward the face.Damage to this nerve causes drop foot. Usually if this nerve is damaged, it will slowly recoverover many months but not always. Nerve damage occurs most commonly in association withthe need for significant leg lengthening with the hip replacement, particularly withdevelopmental hip dysplasia patients.Less than 1% of the time, patients develop extra bone formation around the hip joint whichcauses the hip to be significantly stiffer than desired. This is more likely to occur in men withosteoarthritis. Formation of small amounts of extra bone called heterotopic bone occurscommonly around hip replacements and does not cause a problem. A large amount of extrabone causing severe stiffness rarely occurs and can be treated later by surgical removal of thebone after it has matured. Radiation therapy or medications, such as Indocin, are sometimesused to try to prevent bone formation when the surgeon believes the patient is likely to developthis extra bone.Rarely, the femur will fracture during a hip replacement or from later trauma. Sometimes thesefractures can be treated without surgery but sometimes surgery is required to fix the fracturefragments. Healing can almost always be obtained.The prosthesis itself can break. The stem of the component is under very large stresses andis loaded repetitively and may fracture via a mechanism called fatigue fracture. Smallerprostheses are more likely to fracture. Bigger sizes with large diameters are extremely unlikelyto fracture. Manufacturers are very aware of this problem and today produce devices whichare less likely to fracture compared to prostheses used in the past. We are aware of only twostem fractures in over 5,700 hip replacements done by Dr. Moreland in his career.One should not expect a hip replacement to be as good as a normal hip, although manypatients seem virtually normal. The completeness of pain relief and the degree of mobility ispartially determined by the individual patient’s type of problem. Rarely, patients have painafter surgery which cannot be explained and does not resolve.The length of the leg can be changed to some degree by the hip replacement surgery. Gettingthe leg lengths exactly equal is difficult and is not always the object of the operation. Somedifferences in leg lengths after surgery cannot be avoided and shoe lifts may be necessaryafter surgery. Sometimes, some lengthening cannot be avoided because of dislocationproblems.The most common medical complication in hip replacement is blood clots (deep venousthrombosis or DVT) which may develop in the legs and the pelvic area after surgery. As longas the blood clots do not move up to the heart, the only effect is swelling in the leg, sometimeswith calf or thigh pain. Occasionally, the blood clots may move up through the heart to thelungs causing the patient to be short of breath and have chest pain (pulmonary emboli orP.E.). Dr. Moreland’s replacement patients are given Coumadin (warfarin) which thins(anticoagulates) the blood and helps prevent clots after surgery. Very rarely death can occurfrom large clots moving to the heart and lungs. Dr. Moreland, fortunately, has not had apatient die of this problem. Other measures such as compressive support hose (TEDS), bedexercises, and early walking also help prevent blood clots. 28
  29. 29. A fat embolism is another potential complication of hip replacement. There is fat in the cavityof the bone where the femoral prosthesis is placed. Apparently, if this fat is pressurized, someof it can be driven into the veins which then can carry the fat back up to the heart, then to thelungs and somehow also to the brain. This can cause the patient to have difficulty breathingand to develop neurological problems. Evidence now suggests that evacuating the fat out ofthe femur before the prosthesis is placed probably prevents this complication. Patients willusually recover from a fat embolism problem, if measures are taken to support the patient’sbreathing while the tissues are recovering from the insult of the fat.Anesthetic complications can occur and very rarely the patient can die. Your anesthesiologistwill see you before surgery and should explain the risk of anesthesia and your anestheticchoices. There are two broad types of anesthesia which are used for hip replacement: generaland regional. In general anesthesia you are completely asleep and thus totally unawareduring the operation. In this technique an IV is first started in your arm. The anesthesiologistnext puts multiple monitoring devices on you (EKG, stethoscope, pulse oximeter, bloodpressure cuff), lets you breath pure oxygen for a few minutes, and then puts you to sleep byinjecting a sedative through your IV. Your next awareness is usually when you are waking upin the recovery room.In the regional anesthetic, an IV is also started and the same monitoring devices are placed.Then, while on your side on the operating room table, the anesthesiologist injects medicine inyour back next to your spinal nerves. You will then gradually lose feeling from about yourwaist down. There are two types of regional anesthetic: the spinal and the epidural (oftengiven to women in labor). The spinal rarely can cause postoperative headaches. You can beentirely awake with a regional but the anesthesiologist almost always sedates you so that youare completely unaware of the operation. The final decision as to type of anesthesia is theanesthesiologist’s after consultation with the patient and the surgeon. With the advancedanesthetic monitoring techniques available today, anesthesia is safer than ever before. Dr.Moreland strongly prefers the spinal anesthetic since it is associated with less bleeding, alower rate of blood clots, and patients seem to have less postoperative pain.Blood transfusions carry risk. We use many measures to limit the usage of banked blood.Many patients store their own blood before surgery (autologous blood) and with today’stechniques for testing the blood and screening donors, the blood supply today is safer than inthe past.Other complications can occur, but you should keep in mind that the chances of any significantcomplication occurring is small. As with many things we do in life, major surgery cannot bedone without risk. We will do everything we can to minimize the risk you undertake. Keep inmind that the worse your preoperative symptoms are, the more reasonable it is that you takethe risks inherent in having hip replacement surgery. WHAT ABOUT WRONG SIDE SURGERY?Publicity about patients tragically having surgery on the wrong side of the body has mademany patients very anxious about this possibility. Dr. Moreland has done over 5,700 hipreplacements and over 2,600 knee replacements and has never operated on the wrong side.There are many preventative mechanisms in place and you may get tired of being asked whichside is the correct one. Dr. Moreland during your preoperative office visit usually the day 29