News Category: Hip

Everyone loves a good mystery, but some need to be solved sooner than later. A lack of bone union after a total hip replacement (THR) is one of those mysteries that needs to be solved now. In some surgeries to put in a new hip joint, the surgeon removes the greater trochanter. The greater trochanter is the bony bump that you can feel on the side of your leg near the top of the hip. The piece of bone is wired back in place after the new hip joint is in place.

In some patients the bone doesn’t heal bacl together. This can happen to anyone and often for more than one reason. The most common causes are poor bone quality and putting too much weight too soon on the new hip.

Doctors in France are trying a new device called a trochanteric claw plate to hold the bone together. Made of stainless steel, it’s designed to match the shape and size of the bone. Wires are also used to give better bone contact by pressing the bone together. The plate and wires help the bone heal.

This study reports the results of the claw plate’s use in 71 patients. The average age of the patients was between 66 and 76 years. There were an equal number of men and women. Results were measured using X-rays to look at bone position and healing. Pain and how much a person limped were also measured. Patients were followed for five years.

Doctors considered this treatment method a success. Almost 90 percent of the hips treated healed properly. Patients were able to walk pain-free and without a limp. The authors conclude that the trochanteric claw is the treatment of choice when a THR procedure calls for the removal of the greater trochanter.

A new hip joint can be put in with or without cement. In either case the implant can come loose. If so, the patient may need another operation to revise the hip. Doctors keep track of how often implants fail and what caused the failure. But they don’t stop there. They also pay attention to what happens to the revised hip. This study looks at the long-term results of failed uncemented hips revised with the use of cement.

When an uncemented implant fails, doctors and patients may prefer a cemented revision. Cement holds right away, giving the patient quick pain relief. Using cement may also give the patient with a failed uncemented implant some peace of mind.

Even with a cemented revision, however, doctors found a high rate of failure after the revision. The failure rate was greater than when cement was used in the first place. In fact almost a third of the uncemented implants revised with cement came loose again.

The researchers think this poor result happens for several reasons. It’s sometimes hard to get the cement to ooze into the tiny pores of the bone. This means that the cement fails to make a good connection with the bone. Without this bond the strength of the cement to bone is much lower. There’s also a lot of bone loss that occurs during loosening. And there’s even more bone that is lost during the revision operation. Using a longer stem in the thigh side of the implant has fewer failures. Older patients (greater than 70 years) seem to fare better.

The authors conclude that, in general, revising a hip replacement is best done with cement. The doctor needs to factor in other considerations, such as age, activity level, medical status, and pattern of bone loss already present. Uncemented implants are a good option when little bone remains inside the thighbone.

Some people spend more time picking out ceramic tile for their bathroom than they do choosing the right hip replacement. Thanks doctors and researchers around the world, we don’t have to spend hours and hours figuring out which implant is best.

This study from Austria compares ceramic and metal hip implants. Researchers looked at implant loosening and measured migration of the socket using X-rays. Patients were followed for two years. Hip replacements keep changing as researchers find new and better materials and designs. This makes it hard to compare one type of implant with another over more than a few years at a time.

In this study all patients received the same basic implant design. Some had a socket made of metal; others had one made of polyethylene (a manmade plastic). The ball portion of the hip joint was made of metal for the metal cup and ceramic for the polyethylene cup.

The authors report better results with the metal-on-metal implant. There was less loosening and less movement or migration. These findings were noted at six and 12 months. However, after three years there was no difference in the amount of migration between the two groups.

Migration is one way to tell if the hip implant will fail. The goal is to find a hip implant that doesn’t move once it’s been put in place. Researchers also want to find an implant that doesn’t produce debris (bits of plastic or metal). Debris is also a major factor in joint loosening. When these two issues are addressed, the best hip implant will be obvious. Doctors and patients will be able to spend less time choosing the right implant, and more time thinking about the positive changes after surgery.

Osteonecrosis is the death of bone. Osteonecrosis can cause the hip to collapse. This condition affects the ball on top of the thighbone (femoral head) when the blood supply is cut off. Adults between the ages of 20 and 50 years are at risk for osteonecrosis if they abuse alcohol, take steroids over a long time, or have some kind of trauma to the hip.

Treatment with surgery for early disease is usually successful. The goal is to prevent collapse of the femoral head. If it collapses, treatment is much more difficult. Total hip replacement is the most common treatment for patients over 50 years with bone collapse due to osteonecrosis. For patients younger than 50 with mild to moderate disease, the goal is to restore the round ball of the femur and to save the joint surface. This must be done to prevent collapse and before arthritic changes occur.

Doctors at the University of North Carolina at Chapel Hill propose using open surgery to inject cement into the damaged femoral head. The idea is that the cement will harden and support the area so it won’t collapse. In general, pain is relieved, and mobility improves. If collapse occurs the ball can still be replaced. The results of this proposed treatment are being studied.

In the first study of 22 hips, the long-term results are still unknown. Right after surgery everyone in the study had pain relief and improved motion. After one to three years, six patients ended up needing a hip replacement. Patients with more advanced disease had the worst results.

There are five stages of osteonecrosis from stage 0 (at risk but no signs of disease) to stage IV (bone death with arthritic changes). At stage III, an X-ray or CT scan will show partial flattening of the ball. The authors suggest that patients under 40 with stage III disease could benefit with the cement treatment. But more work is needed to find ways to treat advanced stages of osteonecrosis.

Doctors helping patients with hip replacements face a special problem. The use of some types of hip sockets can lead to bone loss around the implant. For instance, designs that have metal backing in the hip socket and that are not implanted using cement have a tendency to loosen round the implant. Too much bone loss causes the implant to come loose.

Doctors know they need to monitor these patients closely. But there’s no reliable way to measure the amount of bone loss. Often the patient has no symptoms, and it’s too late before the doctor finds the problem. The patient may end up in surgery again.

A major revision operation is expensive and complicated. X-rays to show bone loss around the implant aren’t accurate. CT (computed tomography) scans are affected by the metal, which can cause errors when the images are read.

A new kind of CT scan to measure bone loss is being studied. It’s called spiral CT scanning. This study reports that spiral CT scans allow a precise and reliable measure of metal-backed hip implants. Researchers used special computer software to reduce the extra signals that were showing up in a regular CT scan.

The use of this method to measure amount of bone loss is still in the experimental phase. It has only been tested on animals and cadavers (human bodies preserved for study after death). Still, it’s a very promising start.

Total hip replacements (THRs) don’t last forever. But how long do they last? Most doctors tell patients to expect about 15 years of good service. Some doctors are keeping track to find out the long-term results.

This report updates the results of an ongoing study. Doctors at the Walter Reed Army Medical Center in Washington, DC, started using cementless total hip replacements back in 1983. They’ve been keeping track of the results ever since.

Reports have been published after two, five, and 10 years. This is the 15-year report. Pain (hip or thigh), limp, and use of walking aids were used as measures of success or failure. Doctors also kept track of how many implants came loose and had to be revised.

At 10 years, 96 percent of the patients had no hip pain (or only slight pain). The same results were found at 15 years for 72 percent of cases. Decline in function was thought to be more a result of the aging process than the THR.

More than one-third of the implants loosened because of bone loss. Not all implants had to be revised. The implants that were revised showed quite a bit of wear when removed. The authors of this study suggest that the durability of the early cementless implants was the long-term problem in their series.

They conclude that today’s cementless THR are of better quality. With improved surgical techniques, cementless THR will continue to be a good choice. Better, more durable results can be expected in future studies.

When total hip replacements were done in the 1970s, trochanteric osteotomy was almost always part of the operation. In this procedure, the bony projection along the outside edge of the head of the femur (the upper part of the thighbone) is cut. The incision through the bone may be up-and-down or side-to-side. Cutting into this piece of bone gives the doctor better access to the joint.

Trochanteric osteotomy is no longer used routinely because of the added time it takes and problems that occur after surgery. However, it may be needed during surgery for difficult cases, or when a hip implant must be revised or repaired. By cutting away a portion of the bone, the surgeon can get in and remove cement from a past hip replacement. This approach also provides a clear view of the inside of the femur, making it easier to prepare and implant the replacement stem.

There are three ways to cut the bone. This article reviews all three methods, their uses, and problems with each one. Details of each operation are provided for doctors doing this kind of surgery.

Plicae are folds in the membrane that surrounds a joint. A plica doesn’t necessarily cause problems. However, a plica can sometimes get caught in the joint as it moves, causing clicking, pain, and problems with some movements. Plicae are often found in the knee. So far it has been rare to find plicae in the hip.

These authors report on the case of a hip plica in a 19-year-old cross-country runner. Running had become painful for her, even though she had not had a specific injury. Her hip clicked as it moved, and she had problems standing up from a crouch. MRIs showed some abnormalities in her hip joint, so the doctor did an arthroscopy. Arthroscopy involves inserting a tiny camera into the joint through a small incision. The camera lets a doctor actually see the inside of the joint.

In this case, the arthroscope very clearly showed a plica in the runner’s hip joint. It also showed damage to the cartilage where the plica had been sticking in the joint. Her doctor used the arthroscope to remove the plica. Six months later, the patient had returned to running without pain. She could use her hip normally, and there was no clicking when it moved.

The authors note that there are only five reported cases of hip plicae that caused pain. But they think that hip plicae might go undiagnosed most of the time. As more doctors use arthroscopes in the hip, they believe that more hip plicae will be found. That is what happened with the knee. Knee plicae were once thought to be rare, but now they are often found when doctors use an arthroscope during knee surgery.

When it comes to total hip replacements (THRs), a lot has changed in the past ten years. Patients go home from the hospital much sooner now. New technology, better rehab, and preparing the patient for surgery make this possible. Insurance companies also pay for fewer days in the hospital.

Physical therapists at the Center for Clinical Outcomes Research in New York have been keeping track of THRs for the past 11 years. They report other changes over the years, too. More patients are discharged to rehab centers; fewer go home alone.

When skills are measured, patients are less able to walk or get in and out of bed upon discharge today compared to 10 years ago. The authors report length of stay (LOS) in the hospital may depend on the diagnosis. Patients with hip fractures stay the longest. Patients with osteoarthritis are released the earliest. Ten years ago, men were more likely to leave the hospital sooner than women. Today, LOS and day of discharge is the same for men and women.

The results of this study point out the need for more rehab after discharge. The authors think the reasons for this are the short stay and decreased skill level at discharge. Rehab may have to be done at home or a skilled nursing facility, depending on the patient’s physical needs.

The world of orthopedics is full of unusual problems. Osteonecrosis of the femoral head in young adults is one of the more difficult challenges. Osteonecrosis means bone death. The femoral head is the round ball at the top of the thighbone that fits into the hip socket.

Osteonecrosis can be caused by steroid use, alcohol, trauma, and blood-clotting problems. In some cases, no cause can be found. The first goal in treating osteonecrosis of the femoral head is to save the bone. The second goal is to keep function while relieving pain.

Doctors can use a bone graft from the fibula (the small bone next to the shin bone) in the lower leg to preserve the femoral head. Taken from the cortical bone, the pieces harvested from the fibula have their own blood (vascular) supply. This helps the bone survive in its new location. There, the graft reinforces the outside border of the femoral head. The graft is called a free vascularized fibular graft (FVFG).

If the FVFG fails, the bone will collapse causing even more problems. A total hip replacement may be the next step. However, in a young adult, the implant may not last more than 15 years. That’s why the FVFG is done first to prolong the life of the bone.

The authors of this study took on several tasks. They reviewed and summarized different types of implants used to treat patients with osteonecrosis. They also reviewed results based on the cause of the necrosis. Patients with osteonecrosis from steroid or alcohol use had the worst outcomes.

Pain levels and function were measured for patients who had a FVFG before having a total hip replacement. The researchers compared these results with patients who were treated for osteonecrosis without FVFG. As predicted, the younger patients had the worst results.

Revision of the joint implant is common in patients with osteonecrosis. Over 20 percent of the patients had a second operation after total hip replacement. The authors point this out as the main reason to preserve the femoral head with FVFG for as along as possible before replacing the joint.

Early detection of loosening is important with hip joint replacements. With early detection, the doctor can save the implant with only minor surgery to replace damaged parts. The patient is better off not having the implant completely removed and replaced.

This case report shows how early changes in the joint implant don’t always show up. This 53-year-old man had a total hip replacement eight years earlier. He had hip pain for the last two years. All lab work, X-rays, and bone scans were normal.

The doctors decided to try using positron-emission tomography (PET) scan. A special form of PET, called F-FDG-PET, was used. This test shows areas of inflammation, a possible sign of implant wear.

In this case, the scan was used to look at the soft tissues around the implant. It showed increased glucose uptake. The inflammatory cells use glucose as a source of energy. The presence of glucose tipped the doctors off that a reaction to implant wear was taking place.

The authors conclude that the specialized PET scan is sensitive enough to show tissue reaction to wear. Identifying wear before loosening occurs may help the doctor decide what kind of operation is needed. Another study with more patients is the next step to confirming this finding.

Everyone runs a high temperature after a surgery. It is part of the body’s normal healing response. But infections after surgery can also cause a high temperature. The temperature caused by infection is not normal. It is the signal that the infection needs to be treated.

In the case of total joint replacement surgeries, infections after the surgery are very serious. Doctors must watch any high temperature closely and run lots of tests to be sure there is no infection. It would be very useful for doctors to know what body temperatures are normal for patients who have had joint replacement surgery.

These authors have taken a step toward understanding the way body temperature fluctuates after joint replacement. They studied the records of 88 patients who had a total hip replacement (THR) without any major problems. Temperatures were taken the old-fashioned way, using mercury thermometers under the tongue, because it is considered the most accurate method.

Results showed the expected changes in body temperature over five days after THR surgery. Body temperature actually dropped to an average of 97 degrees F right after surgery; some patients’ temperatures dropped much lower still. This is a known response to anesthesia. Soon after surgery, body temperatures climbed. The highest temperatures were recorded on the day after surgery. Most THR patients ran a temperature higher than 100.4 degrees F in the first five days after surgery, with some patients showing significantly higher temperatures.

This is baseline information. More study is needed to find ways to tell the difference between a high temperature caused by surgery and a high temperature caused by infection. The authors say that the next step would be to look at the temperatures of patients who had complications after THR.

We don’t like to think about it, but problems can occur after an operation. Problems after a total hip replacement (THR) are the focus of this study. Broken wires, bone thinning, implant loosening, and hip dislocation are just a sampling of what can go wrong. One doctor at the Center for Hip and Knee Replacement at Columbia University in New York is working to change this.

Dr. Nay S. Eftekhar compared two groups of patients receiving a THR. The major difference between the two groups was the surgical approach used. In other words, the new joint was put in from the side (trochanteric) or at an angle from the back side of the hip (posterolateral).

The authors of this study found a much lower number of problems with the posterolateral approach. In fact, THR by posterolateral approach had 18 times fewer problems after the operation.

Wire breakage seemed to be the most common problem when the new hip was placed from the side. Using the posterolateral approach avoided this problem. Other studies report a higher rate of hip dislocation with the posterolateral approach. The results of this study don’t support that finding.

Dr. Eftekhar outlines the benefits of using a posterolateral approach with THR, including a shorter time for the operation, less blood loss, and easier placement by the surgeon. According to this study, the posterolateral approach to THR shows improved results compared to operating from the side of the hip.

Hip joint replacements these days are faring well, but they still don’t last long enough. Researchers are designing new joint surfaces to combat wear and tear. Lab tests must be done to see if the changed designs show less wear.

Researchers can measure wear and tear on implant surfaces using new technology. Two- and three-dimensional digital X-ray findings are entered into a computer for analysis. In 2-D, X-rays can’t see everything. Sometimes the edges of the implant (where problems occur) aren’t shown. 3-D studies can overcome this problem, but more X-rays are usually needed. The angle of the extra X-rays makes the view of poor quality.

Researchers at the University of Chicago Hospitals compared 2-D and 3-D computer analysis of joint implant wear. Wear rates were measured every year for an average of eight years. The research team found that the 3-D analysis finds 10 percent more wear. But there’s one major drawback with 3-D analysis. Repeating the test to verify the findings is much harder using this method.

The position of the hip cup (the acetabulum) after it is implanted in the bone can affect the amount of wear occurring in the implant. In this study, the angle and tilt of the cup, called acetabular anteversion, was linked by 3-D analysis to wear that doesn’t show up in 2-D studies.

Are you 55 years old or older and still pain free? Chances are you have osteoarthritis and don’t know it. X-rays show arthritic changes in eight out of every 10 adults age 55 and older.

Knees, hips, and spines are affected most, in that order. Older adults with leg pain may have arthritic changes in both the hip and spine. They sometimes have a total hip replacement (THR) only to develop groin and buttock pain next. Or suddenly they have muscle weakness that isn’t related to the THR.

In these cases, lumbar spinal stenosis (LSS) may be the problem. LSS occurs when age-related changes narrow the canal where the spinal cord and nerves travel. Bone spurs, thickened ligaments, and worn-down joints are just some of the changes leading to LSS.

These doctors from Baylor College of Medicine offer other orthopedic surgeons some guidance. They say that when a patient with a recent THR has severe pain after the operation, look for infection, an unstable implant, or LSS. Location of the pain is a key to diagnosing the cause of the problem.

Groin pain is likely caused by loosening of the implant socket. Muscle inflammation or LSS are two other possibilities. Thigh or knee pain often comes from loosening of the implant at the top of the thighbone. Any sign of nerve injury should suggest LSS. The patient may need a second operation to take the pressure off the spinal nerves. This is called lumbar stenosis decompression.

In older adults considering a THR, the doctor should look for lumbar stenosis. If testing shows both hip arthritis and LSS, the authors advise doing a THR first. Decompression surgery is only done if the patient has symptoms or problems related to the stenosis.

Young athletes are facing some old problems. Piriformis syndrome in older adults has been around for years. Now some young sports enthusiasts are experiencing the same problem.

The piriformis muscle rotates the hip out. It can also help move the hip outward. The sciatic nerve passes through an opening in the pelvic bone and runs along the underside of the piriformis muscle. (In some people, the sciatic nerve goes through or over the top of the muscle.) When the piriformis muscle contracts, it may squeeze the sciatic nerve. The result can be mild to severe buttock pain, called piriformis syndrome. Sports injuries can cause piriformis syndrome in young athletes.

Doctors in Japan have found a way to release this muscle using arthroscopy. An arthroscope is a slender tool with a tiny TV camera on the end. The doctor passes the arthroscope through the skin and muscle to view the sciatic nerve. The lining around the nerve is released by cutting it lengthwise. The piriformis muscle is cut at the tendon. A cavity is formed around the nerve to keep the area open. This operation takes pressure off the nerve.

The procedure is considered minimally invasive, meaning there’s only a tiny puncture hole needed to insert the arthroscope. The doctor doesn’t have to make a big incision to get to the nerve. This operation is done with local anesthesia. The athlete often gets pain relief right away and usually returns to sports quickly after the surgery.

This is the first report of arthroscopic release of the piriformis muscle under local anesthesia. The operation is patterned after the same one used for carpal tunnel syndrome. The patient can report results of the surgery right away.

Hip joint replacements are watched very carefully in patients younger than 50 years old. This is because the implant may not last more than 10 to 15 years. Researchers are keeping track of which implants last the longest and recording the number and type of problems.

Thirteen doctors in several centers pooled their patients to create a larger study group. The first study included about six years of follow-up after the joint was replaced. This second report from the group reports on them after 10 years.

In both studies, information about the patients was gathered. Age, diagnosis, gender, and pain levels were recorded. Use of support during walking, walking distance, and ability to climb stairs were also measured. X-rays were taken, and failure rate was recorded.

The authors report a high rate of wear and loosening of the cup on the socket side of the hip. Almost half of the hips showed signs of failure. Results from other studies are very similar.

Researchers think the cup needs to be redesigned to decrease breakdown of the bone, called osteolysis. Osteolysis and wear on the implant lead to cup loosening. When the cup loosens, a new operation is needed to replace the cup and its liner.

Ongoing research such as this gives doctors and researchers helpful information. In this case, the high rate of hip joint revisions alerted doctors to the need for changes in the implant design. Redesign has already happened, including cups made using highly cross-linked polyethylene. The goal is to decrease polyethylene wear and osteolysis. Results of studies with the same group of patients will be reported at regular intervals in the future.

Bone fracture in young adults often heals in about six weeks. But the aging adult with bone loss or poor bone quality may not have the same result.

Hip fracture is a common problem in older adults. The thighbone (femur) has a wide area of bone just before it angles to the hip socket. On either side are two bumps called the lesser trochanter and greater trochanter. A break that forms a line between these two bumps is called an intertrochanteric fracture. Failed treatment of fractures in this part of the hip is the subject of this study.

Whenever possible the bone is allowed to heal on its own. Sometimes an attempt is made to repair the fracture. A metal plate with screws can be used to hold the bone together during the healing phase. This is called salvage with internal fixation. It can save the patient’s bone.

However, the fracture may collapse if there is bone loss or poor bone quality. Total hip replacement is the next step. The authors of this study looked at the results and problems with hip replacement after salvage internal fixation.

They report that hip replacement is a good treatment option if earlier treatment of an intertrochanteric fracture fails in the older patient. Most of the patients got relief from pain and could get around much better. Before surgery, these patients had poor walking ability or were unable to walk at all. With the hip joint replacement, walking at home and in the community improved. Many patients could walk without support or by using a cane or walker.

The implants that are used to replace the hip joint are made of ceramic, metal, or plastic. The use of ceramic for the femoral head (the round ball at the top of the thighbone) started about 30 years ago. Ceramic is very smooth but sometimes creates problems when used as a hip joint replacement. Ceramic is weak and brittle compared to metal. The early ceramic implants were prone to fracture. With better materials, there are fewer fractures now–only one in 10,000, compared to one in 2,000 early on.

Many people have ceramic hip implants. A group of doctors in France looked at the results of treatment after fracture of the femoral head portion of the implant. They compared the success and problems using different treatment methods. The authors of this study were able to find three factors affecting results of treatment when repairing a fracture in the ceramic femoral head.

The material used to replace the femoral head is important. A new ceramic head can be used. One made of cobalt-chromium is also acceptable. Stainless steel is not advised for the femoral head. Too many patients end up with uneven wear and tear with this material.

Replacing the cup (socket) at the same time the head is revised is also important. The authors say that the cup should be removed and replaced even if it looks normal. Tiny ceramic particles may be embedded in the cup.

Finally, complete removal of the synovium is advised. The synovium is a thin layer of tissue lining the joint. Removing this tissue removes as much of the ceramic debris as possible.

The authors conclude by saying that although fracture of a ceramic head is rare now, the results can be disastrous for the patient. Treatment to revise the fractured implant isn’t always successful. Doctors should follow the three suggestions during revision for a good result.

Alcohol abuse can cause bone death in the hip joint among adults of all ages, especially younger adults. The term for this condition is osteonecrosis. It occurs when the top of the hipbone loses its blood supply. Other factors such as steroid use and fractures can also cause this problem.

Some bones are at greater risk for osteonecrosis than others. One of these is the thighbone (femur). The blood supply to the head on top of the femur (the femoral head) is fairly small. Changes from too much alcohol, drugs, or fractures can reduce the blood flow even more.

Without enough blood, the bone cells start to die. The femoral head may collapse. When this happens, a hip joint replacement (called arthroplasty) may be needed.

In the past, total hip arthroplasty (THA) often failed in patients with osteonecrosis. In fact, there’s a higher rate of implant failure for patients with osteonecrosis than any other hip disorder. The stem that holds the new femoral head is placed down into the femur, and it often comes loose.

This study reviews this problem and updates success with new implant designs and better surgery methods. Two groups of patients received hip implants. Anyone with a single hip replacement had a cementless stem. Patients who had both hips replaced got one with cement and one without.

In all cases, patients were soon able to walk without a limp and without walking aids or support. Activities such as putting on shoes, cutting toenails, and using stairs were much improved. Results were the same for implants that were put in place with or without cement.

The authors conclude that patients with alcohol- or steroid-induced osteonecrosis have a better outcome with the newer joint replacements. Better implant design and improved surgical and cementing techniques seem to be the main reasons for the good results.