News Category: Hip

Patients who undergo total hip arthroplasty (hip replacements) can be given one of several types of manufactured hips or hip parts. One commonly used type of hip is promoted by the manufacturers as having a wear rate reduction of 40 percent to 100 percent; these are lined with cross-linked polyethylene, a type of resin or plastic.

As these types of replacements have been used in real-life, doctors have found that this strength against fatigue break-down may have a trade off in the mechanical trait of the joint. They have found that the joints may not be as able to bear weight and last as long as other types. The researchers in the study examined 4 separate acetabular, or “cup sockets” that were used as hip replacements in 2 separate patients.

Both patients were women, one was 98 kilograms, with a body mass index of 34, and the other was 91 kg, with a body mass index of 32. The first woman had the first arthroplasty of the right hip when she was 52 years old because she had progressive arthritis after having had a fracture and repair of the hip. After receiving the first hip, with the plastic lining in the socket, despite it working, the woman did experience several hip dislocations. About 10 months after the replacement, she began to have difficulty with the dislocations and there was clicking when she put weight on her hip. One month later, the patient underwent a second arthroplasty with a larger shell (54 mm vs the original 48 mm). After 14 months, there were changes in the joint detected by x-ray. By 18 months, the patient was, once again, experiencing dislocations of the hip. Yet another replacement was performed 23 months after the first one had been done.

The second patient had her initial arthroplasty performed because she had a valgus arthritic dysplastic right hip. Seven months after the surgery, she experienced hip clicking when she put weight on the hip. She had revision surgery with a slightly larger shell (56 mm versus 52 mm). She again began noticing dislocations after 22 months and had to undergo another replacement.

When the researchers examined the hip replacements that were removed, they found in the first patient that the first liner was cracked and the second one had fragments near the top. In the second patient’s replacements, the researchers found that the second replacement was also fragmented near the top.

The area of the fragmentation was consistent with damage from stress, the researchers said. However, “the importance of the moderate wear seen in the articular surface of the liners is not clear,” they added. It could be due to the plastic deformation after implantation. Because the researchers used fairly large implants, the lining was thinner than it may be in others. This may have played a role in the outcomes.

The authors conclude that although they have these findings, further research needs to be done on the prevalence of the failure.

X-rays are an excellent diagnostic tool for assessing hip problems. X-rays can be taken from the front (anterior view) or from the side (lateral view). An oblique view is taken at an angle between the front and side or back and side.

In this study, researchers use the frog-leg lateral view to look for hip impingement. The frog-leg view is taken with the patient lying down. The hip and knee are both bent or flexed. The hip is rotated outward. The upper leg and knee are moved out to the side, away from the body. The foot stays close to the body along the inside of the opposite knee.

Impingement means some structure is getting pinched or pressed up against the bone. One particular type of impingement called cam impingement is the focus of this study.

With a cam impingement, the round head of the femur (thigh bone) presses up against the front rim of the acetabulum (hip socket). There is a thin layer of cartilage called the labrum along the rim of the acetabulum. The pinched labrum causes painful symptoms.

Cam impingement occurs if the femoral head is flattened or not quite spherical or round-shaped. This is described as aspheric. A change in the shape of the femoral head also alters the femoral head-neck angle. These factors contibute to the development of impingement.

Standard anterior-posterior (AP) views don’t show the decreased head-neck angle. For this reason, lateral views are used most often to diagnose cam impingement. But according to the results of this study, the frog-leg view gives the most accurate visualization of the aspherical femoral head. Frog-leg views also show the change in the head-neck angle that occurs in patients with cam impingement.

Two groups of patients were included in this study. The first group had back or leg pain. There was no evidence of a hip problem. This was the control group. The second group had groin pain and signs of impingement.

AP, lateral, and frog-leg lateral X-rays were taken for all patients in both groups. The frog-leg view was most likely to show an aspheric femoral head in patients who had impingement. The AP view was a better way to show aspheric heads in the control group.

The authors point out that all three views are helpful in diagnosing hip impingement. But the frog-leg lateral view readily shows hip impingement. It is a reliable and inexpensive diagnostic tool.

Although hip arthroplasties, or replacements, have been done for quite a while now, doctors and researchers are still debating the best ways to do the replacements. A minimally invasive approach to replacing hips has been developed, meaning that incisions are smaller and thought to provide a quicker and more efficient recovery from surgery.

Studies have been done about the different approaches to replacing hips with some surgeons saying that a minimally invasive total hip replacement is better than the traditional one, and other doctors disagreeing. However, it still isn’t known what benefits a minimally invasive procedure would have on the patients. The authors of this study wanted to investigate how patient education, accelerated rehabilitation, and improved pain control affected patient recuperation following surgery. To do this, they enrolled 94 patients who were going to undergo hip replacement. The patients were divided into four groups. Twenty-five patients (group A) received the standard surgery and participated in the standard post-surgery protocol; 23 (group B) received the small incision and used the standard protocol; 25 (group C) received the standard incision and used the accelerated protocol; and 21 (group D) received the small incision and used the accelerated protocol.

Patients were not allowed to participate if they had a body mass index of over 30 kg/m2 or if they had any cognitive impairment or psychiatric illnesses. The patients were between 18 and 75 years old and had been diagnosed with osteoarthritis.

Before the surgery, the patients in standard protocol groups were given information about the replacement and the patient-controlled analgesia, a method that allows the patient to give him or herself pain medication through an intravenous with the push of a button, was explained. They were told they would be walking with help every day, beginning the day after surgery. Three or four days after surgery, they would be discharged to home or to a rehabilitation center. Any patients who were taking nonsteroidal anti-inflammatories (NSAIDs) were told to stop two weeks before the scheduled surgery. They were not told what size the incision would be.

The patients in the accelerated protocol groups were told that they would be given a “fast track” surgery and they would be receiving pills for pain in addition to an intravenous medication needed. They were told that they would be up walking on the day of the surgery and the importance of early movement was impressed on them. The patients were told that they were more than likely to be able to walk and even climb stairs already by the second day after surgery. On discharge, it was preferred that they go home rather than to a rehab, and that patients would receive physiotherapy to help teach them how to walk (gait training) and for exercises. For medications, the patients were to take celecoxib, a medication often given for arthritis pain. Finally, the patients were told that their surgery would involve a small incision.

When undergoing the surgery, all patients had spinal anesthesia, none had a general anesthetic. All received antibiotics before surgery and a blood thinner for six weeks after surgery. If blood was needed, those who had donated blood for later use were given it; others received blood donated from others. As well, all patients were seen for social service to see if they needed help after surgery. This resulted in some patients who were expected to go home going to rehabilitation instead.

The results showed that the patients in the standard group used their patient-controlled analgesia for at least two days. Other medications could be added if needed. They were visited by a physiotherapist the day after surgery. They sat up in a chair, walked if possible, and attempted to do stairs on the third day if able.

In the accelerated group, the patients took oral pain relievers, as well as celecoxib again, once per day, if they could tolerate it. If intravenous medication was needed, it was available. They were seen by a physical therapist a few hours after surgery when the patients were assisted into a chair or they walked if able. That was repeated twice a day after.

In order to measure the functional outcome of the surgeries, the patients were tested by the linear analog scale assessment, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the Short Form-36 (SF-36), the Harris hip score, and the lower extremity functional score.

The researchers found a big difference between the patients in all groups when they were assessed by all scales and patients who were in the accelerated protocol group did have a significantly better outcome, regardless of whether the incision was small or large. The patients in these groups walked earlier and farther than those in the standard protocol. However, there were no differences between groups when assessing the amount of pain medication used, with the exception of the narcotic or opioid medications. The accelerated group used more. There was no difference in patient groups regarding if blood was needed. In terms of hospital stay length, those in the accelerated program were discharged, mostly to home, after an average of 3.5 days, with a range from 2 to 5 days. In the standard group, the average was 4.2 days with a range from 3 to 8 days.

Of interest, the researchers point out that in a survey from 2004, surgeons said that they had changed some of their routine with hip replacements, including giving pain medications before pain is severe, improving patient education, using different types of anesthetic and different surgical equipment, and being more aggressive with the rehabilitation after surgery.

There are some weaknesses in the study. Because there are several differences between the standard and the accelerated protocols, it’s not possible to tell if any one specific change had more influence than any other. However, the study does emphasize the importance of patient education, receiving pain medication before it is absolutely needed, and a more aggressive rehabilitation period after surgery.

Tenderness without inflammation alongside the hip is called greater trochanteric pain syndrome (GTPS). This condition is not the same as hip bursitis, which does have inflammation.

In this study, researchers look at how often (prevalence) GTPS occurs in a group of adults ages 50 to 79 with hip pain. Anyone with a total hip replacement was not included.

The secondary goal of the study was to find out if GTPS is linked with sex, weight, or other problems in the lower limb. It’s possible that GTPS may be more likely to occur in people with low back pain or knee osteoarthritis. At the same time, the authors looked to see if hip internal motion or level of physical activity were limited in patients with GTPS.

After examining over 3,000 adults with hip pain, they found that about nine per cent of men and 24 per cent of women had GTPS. This makes GTPS a common problem. Factors linked with GTPS appear to be female sex, tenderness over the iliotibial band (ITB), and knee osteoarthritis. The ITB is a band of connective tissue along the outside of the upper leg. The ITB goes from the hip to the knee. Knee pain and low back pain were also associated with GTPS.

This study could not say if the GTPS came first or if knee pain and arthritis, low back pain, and obesity were caused by GTPS. Longer studies are needed to identify cause and effect. This study did not answer the question of how to treat this problem. Future research to find out about the final outcomes of intervention are also needed.

Younger adults with hip arthritis have more treatment options now thanks to a procedure called hip resurfacing. Instead of removing the damaged head of the femur (thighbone), the surface can be smoothed and rounded again. A metal cap is placed over the new surface. Sometimes the hip socket is also replaced with a thin metal cup.

New designs of hip resurfacing have decreased the failure rates by up to 30 per cent. This news was presented at the 2007 Annual Meeting of the American Orthopaedic Association.

Since the first resurfacing implants were used, the type and design have improved. The surgical tools used to do the operation are better. And surgeons are choosing patients more carefully. These changes have made it possible for long-term success of hip resurfacing.

Patient selection for this procedure is limited to those patients who are younger than 65 years old. They must not have osteopenia, a decrease in bone mineral density. A low risk index is desirable.

The risk index used is called the surface arthroplasty risk index (SARI). It is a tool that scores patients based on the number of risk factors for implant failure. A total score should be less than three before the person is considered a candidate for hip joint resurfacing.

Hip resurfacing has its own pros and cons. These are different from total joint replacement. The risk of femoral neck fracture is much higher with resurfacing. Metal ion release can cause problems later with loosening of the implant.

But the faster recovery and improved function make this a desirable option for hip arthritis in younger adults. Returning to full function and getting back to work sooner are major benefits of this operation.

In the short time since hip replacements were first introduced, the procedure has changed and improved in many ways. One of those developments has been the hip resurfacing arthroplasty. Hip resurfacing arthroplasty is a type of hip replacement that replaces the arthritic surface of the joint but removes far less bone than the traditional total hip replacement.

Because the hip resurfacing removes less bone, it may be preferable for younger patients that are expected to need a second, or revision, hip replacement surgery as they grow older and wear out the original artificial hip replacement.

In this review article, surgeons from the UT Southwestern Medical Center in Dallas, Texas bring us up-to-date on the latest information about hip resurfacing. How well do they work? What are the potential problems or complications? First, let’s take a look at a little bit of history around this procedure. It was first used in the 1970s, but there were too many hip fractures and the components used didn’t hold up.

So, the procedure fell out of favor in the United States. But surgeons in Australia and Europe continued to improve the surgical technique, instrumentation, and implant design. During that time, two generations of hip resurfacing systems have been developed. Since 2006, the Food and Drug Administration (FDA) has approved two different implant systems: the Birmingham Surface Replacement (BSR) System and the Cormet design.

There are some studies now to help us look back and see how effective these implants have been and what problems are still left to deal with. Using data from the 1000s of hips done outside of the United States along with studies done in the states, it’s clear that the overall revision rate is still higher for resurfacing than for standard total hip replacements. But the rate is still small enough to make it worth having the procedure for the many patients who aren’t ready yet for a complete total hip replacement.

Studies show that women are more likely to have a failed resurfacing procedure. So are patients who’ve had a previous hip surgery or anyone who has osteonecrosis (loss of blood supply to the top of the femur or thighbone causing death of bone cells). And anyone with inflammatory arthritis or developmental dysplasia of the hip is at increased risk for implant failure.

Based on this information, surgeons are careful when choosing patients for the resurfacing procedure. For example, patients are younger and more often male than female. Anyone who is obese is not considered for the procedure. Patients in good overall health are more likely to receive hip resurfacing. As a result, implant survival is up and complications are down. Rates of re-operations are also lower for surgeons with extensive experience with the hip resurfacing procedure.

So how successful is hip resurfacing compared to a standard hip replacement? Early results suggest that patients receiving hip resurfacing implants have better overall function with greater motion and higher activity levels compared with patients who had a total hip replacement. Patients with hip resurfacing implants also have better waling speed and hip kinematics (movement).

In some ways, it’s difficult to compare outcomes of hip resurfacing versus total hip implants. Patients in the hip resurfacing groups tend to be much more active. Many are involved in sports at least four hours a week. Implant survival in both groups is probably affected by activity level (high versus low).

What about complications? How do these compare between the two procedures? Fracture of the femoral neck is the most common problem associated with hip resurfacing. In fact, it’s the number one cause of implant failure. Again, studies support the idea that women and obese patients are at increased risk for these types of fractures.

Besides eliminating these patients as potential recipients of the procedure, studies of cadavers (hip specimens saved for study after death) have added some more helpful guidelines. Using different surgical techniques and then loading the specimens until they failed, researchers found that how the implant is placed in the hip makes a difference. Tilting the implant slightly off center (valgus position) reduced the fracture rate considerably.

Other surgeons have focused their attention on the effects of different surgical approaches when resurfacing the joint. They found that using a posterolateral approach (from the back and side) reduces blood flow to the femoral head. Using an anterolateral (from the front and side) approach may yield better results.

Computer-assisted surgery may help improve results with hip joint resurfacing. Computer navigation has the advantage over manual techniques of a more accurate placement of the implant. Getting the best component position costs more, but it might be worth it if the revision rate can be substantially reduced.

And one last concern about hip resurfacing: metal ion release. Because the component parts of the implant are metal, tiny pieces of metal ions flake off and get trapped inside the joint forming a tumor-like cyst or entering the blood stream. This could become a problem for anyone with metal hypersensitivity or for very active adults. Increased activity has been shown to increase ion levels in the blood. As a result, implant failure may require conversion to a total hip replacement.

Is joint resurfacing superior to a standard total hip replacement? That question remains unanswered. The authors conclude that this new technology bears watching. A high-degree of surgeon skill is required, so it’s not something every surgeon is going to be able to offer. Computer navigation systems may help further refine the procedure. The jury is still out until safety concerns about metal exposure and the development of pseudotumors are answered.

Early signs of hip osteoarthritis (OA) in young adults has puzzled surgeons for years. Hip dysplasia (shallow hip socket) is a common cause of OA. But these patients don’t have dysplasia. Genetics and overload of the joint were two other popular theories. But no proof has been found to support these ideas.

More recently, a new theory has emerged. Femoroacetabular impingement (FAI) may be the cause of hip pain (and later OA) in these patients.

FAI is the abnormal contact between the femoral neck and the acetabular rim (hip socket). The femoral neck is the supporting structure between the femur (thigh bone) and the round head of the femur that fits into the hip socket.

Minor changes in the anatomy of the femur or acetabulum may be at fault. The result of these changes is the pattern of abnormal contact described. Over time the bone starts to rub along the cartilage of the hip and the acetabular rim called the labrum.

The femoral head can get jammed into the acetabulum during normal motion. Tears in the cartilage start to develop. The cartilage under the labrum may pull away from the bone. These lesions eventually progress to form degenerative joint disease.

The patient reports groin pain that comes and goes with activity. Walking long distances especially aggravates the condition. The pain may travel from the hip to the knee. The diagnosis can be difficult to make. Special tests and careful attention to X-rays and MRIs may be helpful.

Treatment begins with conservative care. This includes changing activities to avoid aggravating the condition. Anti-inflammatory drugs may be used. Symptoms can be controlled but usually surgery is needed to allow full activity in these young patients.

The surgeon dislocates the hip. The bone is shaved to restore the normal rounded anatomy. The surgeon is careful to preserve the blood vessels and balance the hip joint anatomy. The torn labrum is repaired if possible or removed. The hip is put back in the socket.

The authors describe the operation in detail using several different surgical methods. Open incision, arthroscopic surgery, and the anterior approach are included. New ways to use traction to dislocate the hip are also being studied.

There’s a general trend toward more patients having total hip or total knee replacements at a specialty hospital instead of a general hospital. In this study, results of joint replacement surgery for Medicare patients were compared for these two locations.

The use of specialty care hospitals for surgery of this type has come under sharp criticism. Some people suspect patients who go to a specialty center have more money. They may be healthier, so their risk of complications is less. The center makes more money because they don’t treat the poor and needy.

Others claim that specialty centers can focus on improving their results at a reduced cost compared to a general hospital. The results of this study support the idea that patients at a specialty hospital come from a more affluent background (based on zip codes).

Over 50,000 Medicare patients who had a total hip replacement were included. There were also nearly 100,000 Medicare patients reviewed who received a total knee replacement reviewed.

Results were measured by how many problems occurred within 90 days of the surgery. Infection, hemorrhage, blood clots, and death were tracked. Length of hospital stay was recorded. And they looked to see if patients had to be transferred from the hospital to another facility to handle special problems.

After careful analysis, they found that patients using the specialty hospitals had better outcomes compared to patients in the general hospitals. The death rate was lower. They were less likely to have the complications listed. This may be explained by the fact that they were less likely to have general health problems such as diabetes, heart disease, or kidney failure.

The authors offer several other explanations for the better results in specialty hospitals. It could be just the sheer volume of cases gives them the edge. Or perhaps the staff has greater experience and expertise in the specialty hospitals. Communication among the clinical teams could be a key factor as well.

On the other hand, patients were transferred from the specialty hospital to another acute-care hospital more often than patients who were treated in a general hospital first. The reason for this may be the lack of staff and equipment to handle special problems. Or perhaps they transferred patients who were more complicated and expensive. They lose money under the current Medicare payment system with delayed discharge.

The authors suggest more study is needed to understand the reasons behind the differences in results between specialty and general hospitals. It would be good to do this same study with patients who aren’t on Medicare. This would help show how much that factor plays a role in the results.

While many people associate joint replacements with older people, many younger people end up needing them as well. Unfortunately, this is one time when young age may actually work against someone. Many orthopedic surgeons are reluctant to do full hip replacements on patients who are under 50 years old because of their active lifestyles and life expectancy. These two factors can bring about the need to revise the hip replacement at a later date, causing another surgery. IN an effort to reduce the use of full replacements, surgeons are now doing a metal-on-metal sort of hybrid partial replacement, called resurfacing total hip arthropasty (THA). It appears to have a longer lasting outcome. This procedure doesn’t involve the whole hip and is easier to remove than a full replacement, if needed.

The authors, believing that resurfacing THA is better for younger, active adults, compared the findings of patients below 50 years old with those over 50 years. The 576 patients in this study had a hybrid metal-on-metal resurfacing and were split into group 1, patients below 50 years (350 hips in 295 patients, average age was 41.2 years) and group 2, over 50 years of age (336 hips in 281 patients, average age was 57.4 years). Three quarters of the patients were men.

The patients were followed up at 6 weeks, 4 months, and 1 year, and yearly after that for x-rays. The researchers found no differences in the state of the hips between the patients in either group. Measurements using University of California Los Angeles (UCLA) hip scores showed an improvement for pain, walking, function, and activity, with no difference in ages. After 5 years, the survivorship of the bones was 97.8 percent, showing that the metal-on-metal resurfacing THA performed well.

The authors pointed out that metal-on-metal resurfacing THA is relative new still, only 10 years, so long-term results are not yet available.

Today’s modern adult is active and on the go. And many adults are wearing out their hips and knees. Total hip replacements have been reserved for older adults. This leaves younger adults with pain from arthritis without many options until now. A new orthopedic procedure called total hip resurfacing may be changing all that.

Hip resurfacing is a type of hip replacement that replaces the arthritic surface of the joint. But it removes much less bone than the usual total hip replacement. Instead of cutting off the femoral head and replacing it, a metal cap is put on the outside of the femoral head. The femoral shaft is never disturbed. This means that when a revision is needed, the femoral shaft can be used to hold the femoral implant. It’s as if there has never been an artificial joint. The bone in this area has not been cut away or cut down.

Total hip resurfacing can improve hip range of motion. But by how much? In this study, surgeons from the Joint Replacement Institute in California look at hip motion before and after hip resurfacing. All patients were followed for one full year.

Results showed that a person’s preoperative hip motion gave an indication of the postoperative results. Those patients with higher degrees of hip flexion had better flexion after the procedure. Patients with less motion did regain more total range of motion. No increase in motion was seen after six months.

The authors conclude that hip resurfacing is a good alternative to total hip replacement. Young patients can avoid some of the stiffness and loss of motion that comes with putting off surgery because of their age. Now hip motion can be restored to normal or near-normal amounts.

A snapping hip can cause deep groin pain, burning in the groin, or a popping/snapping sensation that can be quite painful. It often doesn’t respond to conservative treatments like rest, stretching exercises, ultrasound, or anti-inflammatory drugs.

The snapping can be caused by one of three injuries inside the hip. The most common cause is a layer of connective tissue that begins on the outer side of the hip joint and goes down to the shin may catch on the greater trochanter, a spot on the top of the femur that attaches several muscles. A snapping hip can also be caused by tears in the tissue in the hip joint or a tendon may catch and snap across the femoral head.

Researchers have been looking at the most effective way to treat snapping hips, relieving the pain and increasing hip movement and range of motion. One study looked at the results of a 6-8 week program of hip stretching, however, it showed that only 36 percent of the patients improved without having to progress to surgery. Another trial in which patients took part in a 3-month study found that 63 percent of the patients improved with this non-invasive treatment.

Surgery has been the last option for treatment of painful hip snapping and involves tension-release or lengthening of the muscle and tendon. Following surgery, patients have to rest for about 3 months. Surgery introduces the possibility of complications, reportedly in 43 percent to 50 percent of patients. In one study, 12 percent of the patient complications were directly related to the surgical incision itself, and another study showed 11 percent of incision-related complications.

In this study, researchers followed 6 patients who complained of chronic snapping hips and who had previously received at least 6 months of treatment that involved rest, stretching, strengthening, and NSAIDs (non-steroidal anti-inflammatory drugs), but did not experience relief. The study began with 45 patients, but only the 6 who were followed met all the criteria and chose to remain in the study.

All 6 patients’ hips were evaluated by magnetic resonance arthrography. To do this, doctors inject liquid into the hip joint and look at images that are made by radio waves. During the procedure, the patients received an anesthetic injection to the hip to see if this would relieve the pain.

When the paint was not relieved, the patients underwent an ultrasound of their affected hip and were given another anesthetic injection, directly into the tissue at the front of the hip, called the psoas bursa. The patients then followed a rehabilitation protocol of using crutches for 5 weeks, gradually increasing weight bearing as the strength of the hip increased.

At 1-year follow-up, all of the patients reported 100 percent relief from pain and that the hip snapping had not returned. Two patients did complain of slight pain occasionally, but they still rated their pain relief at 100 percent. The also agreed that they had no complications from the procedure and that the repaired hip was just as strong as the other.

The authors of the study concluded that using ultrasound to evaluate the location of the injury and to guide the anesthetic injection is a safe outpatient procedure that provides relief from snapping hips.

In recent years, resurfacing arthroplasty for the hip has become possible. Hip resurfacing arthroplasty is a type of hip replacement that replaces the arthritic surface of the joint but removes far less bone than the traditional total hip replacement.

The advantage of hip resurfacing is that by removing less bone it is possible to do a total hip replacement (THR) later. But surgeons are wondering if this type of revision is really possible? How often does it happen? There haven’t been any studies on this conversion since 1980. And many things about the devices and the procedures have changed since then.

In this study, surgeons at the Joint Replacement Institute in Los Angeles, California review a group of 20 adults who had the resurfacing procedure (the study group). All patients with resurfacing arthroplasty received the same metal-on-metal implant. The femoral head portion was cemented in place for all patients. The stem was only cemented in about 40 per cent of the cases.

They compared the results with a similar group of patients who had a THR (the control group). Pain, walking, function, and activity were used as the measures of results. X-rays were also reviewed for both groups.

They found no differences between the groups. Outcome measures were the same. Operative time, blood loss, and bone loss were also equal between the two groups. The number of complications was the same between the two groups.

The authors conclude that the proposed advantage of resurfacing arthroplasty (easy revisability) is real. Successful conversion to a THR is possible. They suggest a larger study needs to be done to confirm these findings. Longer follow-up time is also advised.

Fracture during or after an uncemented total hip replacement (THR) is a serious complication. There may be a new way to prevent this from happening. In this study, Dr. S. F. Harwin from the Albert Einstein College of Medicine in New York reports on using the skylight sign to prevent fractures.

The skylight sign is a thinning of the bone seen by light coming through the bone. Thinning of the bone from bone loss can occur as a result of a natural defect in the bone or from other causes such as osteoporosis and arthritis. If this sign is present, the surgeon must be careful to avoid reaming (removing) bone from this area.

Bone is usually removed from inside the shaft of the femur (thigh bone) during the THR operation. This makes room for the stem of the implant to fit down into the femur. By checking for the skylight sign, Dr. Harwin was able to reduce the number of fractures in his THR patients.

In a study of 420 hips, 23 percent of the patients had the skylight sign. Wire cables were used around the femur before the bone was prepared. The cables were left in place when fractures or defects were observed. The cables gave stability to the bone and protected it during rehab. The surgeon can also change the size, shape, and type of implant used when the skylight sign is seen.

Even with these steps taken, eight per cent of the patients with skylight sign fractured during the operation. The authors conclude it isn’t always possible to prevent femoral fractures during THR. This complication can be reduced by screening for skylight sign and making necessary adjustments during the operation.

There’s a report that says about 200,000 total hip replacements (THRs) are done each year. But how do they know that? Well, the Agency for Healthcare Research and Quality (AHRQ) gathers data from hospitals across the United States and reports on it.

In this report, over eight million hospital records from one database and nine million from five different states were reviewed. The number of total, partial, or revision hip replacements were identified.

It turns out that besides the 200,000 THRs done, there were also 100,000 partial hip replacements, and 36,000 revision hip replacements. Although this seems like a large number of operations, THR is only one per cent of all surgeries done in the U.S.

Patients having any of the hip replacement surgeries were usually 65 years old (or older). Surgery was elective (planned) for most people up to age 75. After age 75, 80 per cent of the patients were emergency operations.

Three-fourths of all patients had one or more other diseases or problems at the time of the hip surgery. Most often they had diabetes, heart failure, or kidney problems.

Number of complications and deaths were tracked for the first 30 and then 90 days after the hip surgery. The most common problems were blood clots, pressure ulcers, and infections. Sometimes excessive bleeding and hip dislocation were post operative problems, too.

Patients getting a partial hip replacement had the highest number of complications. They were often older, sicker, and treated in smaller hospitals where fewer hip replacements were done routinely.

And finally, the study showed that most patients having a THR have a main diagnosis of osteoarthritis. Partial hip replacements are done most often on patients with a hip fracture. In particular, there is a break in the neck of the femur (thigh bone). Revision hip replacement is usually done when something has gone wrong with the original implant or graft.

Besides reducing hip pain, many patients hope to walk better after a total hip replacement (THR). We know that overall function is closely linked to the ability to walk during daily activities. In this study from the Netherlands, researchers looked for a way to test gait (walking) recovery after THR.

All patients expecting to have a THR were tested six weeks before the surgery. There were three parts to the test. Patients walked 20 meters at three different speeds (regular pace, fast, slow) while counting backwards from 50 by threes. Adding a mental task helps measure the ability to walk and do something else at the same time.

Everyone was retested six months after surgery. This time frame was used because many studies show that most of the improvement in walking comes in the first six months after the THR. A computer program was used to analyze walking speed, step length, and endurance.

The authors report significant improvement in all three measures of speed, step length, and endurance. Everyone could walk farther in six minutes after the surgery compared to before.

Half the group had additional support. They watched a video and received telephone calls to give them extra information. This group did not have better results compared with the group who did not receive the extra attention.

This study confirms the benefit of using a three-part test to measure gait recovery after THR. This test gives better results than just using one test to measure walking at the patient’s preferred pace. Assessing gait at different speeds should be part of the before and after testing with THR patients.

Hip resurfacing arthroplasty (HRA) is being done on young, active adults with advanced arthritis. HRA is a type of hip replacement that replaces the arthritic surface of the joint but removes far less bone than the traditional total hip replacement.

Maintaining vascular supply (blood flow) to the hip during HRA is important. Reduced blood flow can cause early failure of the implant. In this study, blood flow to the femoral head is measured before, during, and after the HRA procedure in 10 patients.

All patients had a surgical dislocation required for hip resurfacing. The femoral head was dislocated anteriorly (forward). A laser probe was placed in the head of the femur to measure blood flow. Measurements were taken. The procedure was carried out, and a final blood flow reading was taken.

The results showed a 70 per cent decrease in blood flow to the head of the femur after standard reaming and preparation for the HRA. This study shows that hip resurfacing interferes with the blood supply. The risk of implant loosening and bone fracture increases with decreased blood flow to this area.

Although blood flow to the femoral is not disrupted when it is dislocated, the cylindrical reamer cuts off all of the reticular vessels entering the femoral head. Reticular describes a network of blood vessels along the surface of the bone.

The authors advise surgeons to direct the cylindrical-shaped tool used as a reamer superolaterally (up and out). At the same time, it’s best to stay as close to the inferomedial (lower, inner) neck of the femur. Suggestions were also made to use a larger femoral implant. Problems with this solution are discussed.

In this case report, Dr. Lachiewicz from the University of North Carolina at Chapel Hill described a 60-year old man with a large mass in his thigh. The problem developed many years after a total hip replacement (THR).

Twelve years ago, the patient had a revision operation of a cemented THR that had come loose. At the time of his recent exam, he was not in any pain or distress but walked with a moderate limp. The mass in his thigh was not tender or painful. He was not very active due to a serious lung problem.

Testing with X-rays, CT scans, and lab work helped the physician make a diagnosis. The mass was a fluid-filled pseudotumor. When it was drained and examined it was found to be filled with tiny debris material from the polyethylene hip implant. The mass filled up with fluid again within 10 days.

Even though the patient was pain free, because the problem kept coming back, the decision was made to reoperate and revise the hip replacement. The implant was not loose, so the socket and the screws were not removed. The mass was cut out. The polyethylene liner and head of the femur were replaced. The old liner showed signs of discoloration where it was next to the mass.

This patient’s problem of a fluid-filled mass in the thigh 12-years after a hip replacement is rare but treatable. Results were excellent after revision surgery. The patient could walk without a limp. The mass did not come back.

Hip fracture can be a devastating injury in the older adult. Osteoporosis or brittle bones makes bones more likely to break. Trying to repair a broken hip by using pins or screws to hold it in place can be difficult when the bone is osteoporotic.

There is a class of medication called bisphosphonates that can help improve bone strength. In this study, surgeons from Italy tested the idea that screw fixation could be improved by having patients with hip fractures take bisphosphonates.

Women 65 years old and older with a hip fracture were divided into two groups. All patients were treated with surgery (pin fixation) within 48 hours of the injury. Group A was given an oral bisphosphonate (alendronate, also known as Fosamax) for three months after the fracture. Group B did not receive the drug.

X-rays were used to show the position of the screws and the condition of the bone around the hardware. Fixation strength was also measured using an extraction torque gauge. This tool gives the surgeon an idea of how much force it would take to pull the pin out of the bone.

The results showed that in Group A, the extraction torque improved over time. In Group B the extraction torque remained the same. The authors concluded there was a positive effect of alendronate on screw fixation for osteoporotic patients with a hip fracture.

Ballet dancers often report a snapping sound or sensation in the hip. It may or may not be painful. In this study, real-time ultrasound (US) is used to identify the cause of the snapping. Dancers were also examined by a doctor and a physical therapist.

Real-time ultrasound allows the tendon to be examined as it moves across the hip joint. Abnormal or jerky movements of the iliopsoas tendon and iliotibial band (ITB) were of special interest. The iliopsoas muscle and tendon help flex or bend the hip. The ITB is a band of connective tissue that goes from the hip to the knee along the outside of the thigh.

Twenty-six (26) dancers from a professional ballet company and school were included. Most of the dancers had symptoms of snapping hip on both sides. Half reported the snapping started when they were 14 to 16 years old. Many could make the hip snap on purpose. Some dancers snap the hip to make the pain go away. For others, snapping is a habit.

US results showed that the iliopsoas tendon moving over the bone caused the snapping in almost two-thirds of the cases. Sometimes the tendon rolled over the bone and got stuck in the muscle. Only a small number of dancers (four per cent) had a snapping ITB. US was unable to identify the cause in the remaining one-third of the dancers.

Examiners were unable to identify the exact cause of the snap without an US. Even with US, it’s not clear if later hip problems develop because of the snapping. Dancers do not seem disabled by this problem as much as it is annoying.

Future studies are needed to follow dancers for years to see what happens naturally. It may be possible to identify dancers at risk for snapping hip syndrome and prevent it. This is especially important if it turns out that any amount of disability occurs as a long-term result of snapping hip.

For 30 years researchers have looked for ways to reduce bone loss after total hip replacement (THR). The stiff implant results in atrophy of the bone. This reaction occurs as the bone reacts to the mismatch in materials where the implant meets the bone. Bone resorption of this type is called stress shielding.

Many studies have tried to identify the cause of stress shielding. Stiffness of the femoral stem could be the problem. The femoral stem fits down into the femur (thigh bone). It is attached to the new ball-shaped femoral head that fits into the hip socket.

Or perhaps the cause of bone resorption is the type of material used to make the implants. Other scientists have studied the shape and angles of the stem looking for an answer. The goal is to find a way to reduce postoperative bone loss. Stress shielding can cause fractures further compounding the problem.

New femoral designs are the subject of this article. The authors ask the question, Do they influence stress shielding? Only studies using dual-energy X-ray absorptiometry (DEXA) were included. DEXA allows measurement of bone loss both before and after surgery.

The results of different types of stem design were reviewed. The following findings are reported: