News Category: Knee

Most total knee replacements (TKRs) last 10 to 15 years. In this study, long-term results of the low contact stress (LCS) meniscal-bearing knee replacements were reviewed. Wear pattern and survival rates are reported at the 15-year follow-up and beyond.

All patients were older men from a Veterans’ Hospital in Kentucky. Surgery for a TKR was indicated by pain from arthritis. The pain could not be controlled by conservative measures. X-rays were used during the follow-up period to look for implant loosening and position.

The most common reason for failure of the mobile-bearing knee replacements was loosening. Uncemented parts were more likely to come loose. Infection, fracture or dislocation of the polyethylene (plastic) liner, and instability were the other modes of failure reported.

The authors make note that fracture of the liner was the most common reason for implant failure after 10 years. In the LCS meniscal-bearing TKR, a bearing fracture occurs when the bearing is subluxed (shifted back) while the knee is bent.

The overall survival rates of the LCS TKR were 90 per cent at nine years and 71 per cent at 15 years. After 15 years, the survivor rates declined dramatically. These results are similar to reports by the groups who first designed and studied the LCS implant.

Osteonecrosis (death of bone tissue) of the knee often requires management by a knee arthroplasty, or replacement. Spontaneous osteonecrosis usually occurs on in one compartment or section of the knee, while secondary osteonecrosis – caused by disease or medical therapy – affects more than one compartment. Spontaneous osteonecrosis usually occurs in patients older than 55 years, while secondary osteonecrosis can occur at any age.

Total knee arthroplasties replace the whole knee, while unicompartmental knee arthroplasties (UKA) only replace a part of the knee. The authors of this study wanted to examine whether UKA was effective in relieving pain and improving knee function for people with spontaneous osteonecrosis, if the lower leg would be aligned properly, and if the UKA is as durable as a total replacement.

To perform the study, researchers reviewed 30 patients, average 71 years (range: 51-88 years), who had 31 knees treated with UKA. Twenty one knees had spontaneous osteonecrosis and 10 had secondary. The researchers used Knee Society scores to evaluate pain and function, and they evaluated lower leg alignment and durability of the implant through imaging tests. All patients were seen before surgery, at 3 months after surgery and then yearly until the last follow up.

The results showed an improvement in knee function by final follow-up assessment. On a scale of 100, the average pre-operative score was 56 for the pain and 50 for function. At the end of the study, the average was 95 for pain and 88 for function. Seventeen patients were enthusiastic about their experience, 11 were satisified, 1 did not notice any change and 1 was dissatified.

When assessing the alignment of the lower leg, the researchers found that 27 of the 31 knees achieved an acceptable alignment. Finally, the 12-year survival rate of the UKA was almost 97 percent.

The authors wrote that there were some drawbacks to the study. They indicated there was no control group, for example. However, they said that by using their selection criteria, they felt that the UKA is a viable option for both spontaneous or secondary osteonecrosis of the knee if it is contained to one section or compartment.

Originally, total knee arthroplasty (TKA), or replacements, were for older people who had often begun to slow down or limit physical activities. However, the population of patients undergoing TKA is getting younger and more active – and more ethnically and culturally diverse, requiring the ability to flex the replacement in ways previously not needed.

The authors of this study wanted to identify articles in the literature that reviewed the postoperative range of motion of TKA. Among the articles one reviewed TKAs for stiffness and flexion (bending) contracture before the surgery. The findings of that study were that the more limited the flexion and the stiffer the joint before surgery, the more reduced the flexion would be after surgery.

Another study, looking at physiotherapy after surgery, determined that postoperative physiotherapy was particularly important, especially now that hospital stays after surgery are shorter than they have been in the past. The study also notes that the effective use of pain medications to encourage mobilization and flexion plays a role, as does patient motivation. It was also found that the patient’s state of mind after surgery can also have a significant effect.

Some studies looked at technical errors during surgery, while other examined motion of the implants. Finally, some studies reviewed the actual type of TKA design, how it is attached to the bones and how it operates.

The authors discuss the findings of the different studies in relation to the need of the receiving population, some of whom require the knee to be very flexible due to the need to squat or bend, for example. The researchers say, however, that merely the choice of the prosthesis will not ensure that the patient will regain suitable flexion of the knee because of the many variables that come into play, as evidenced by the studies that were reviewed.

What was once thought to be a procedure only for older people, knee arthroplasties (replacements) are becoming more necessary for younger, active patients. Currently there are other surgical options for patients under 55 years old who have arthritic disease, causing pain and immobility to the joints, particularly the knee and hip.

Although other options for treatment exist, many don’t provide long-term relief and may affect the function of the knee. However, many surgeons are still reluctant to opt for arthroplasty with the younger patients, citing higher failure rates than with older patients and the need for surgery revisions later on. The authors of this study investigated whether a total knee arthroplasty (TKA) would be better and stronger for this population if it was a cemented arthroplasty.

Researchers used a registry for joint replacements to find patients, over a 14-year period, who had had knee arthroplasty. The patients had to have been under 55 years old at the time of surgery. The researchers identified 1047 knee arthroplasties with follow up of between 0 to 171 months. Endpoint for the study was revision surgery of the replacement, which could be removal, exchange, or the addition of a component.

Interestingly, the researchers noted that, through the course of the study, the total percentage of the registry’s population became younger: those under 55 years represented 4.6 percent in 1991; this rose to 17.1 percent by 2005.

The arthroplasties performed were cemented, cementless, a hybrid, or unicompartmental (UKA). The results showed that 73 patients required revisions over the study period. Over the 14 years, there was a 74.5 percent survival for the arthroplasties. The cemented group had the highest survival rate, followed by the UKA and cementless groups, which had similar rates.

The patients with cementless implants were 2.7 times as likely to need revisions compared with cemented implants, while those with the UKA were 2.9 times as likely. Loosening of the implant occurred in 31.5 percent of the cases needing revisions, wear and tear on the bone (osteolysis) in 19.2 percent, and progression of arthritis in 13.7 percent.

One the information was analyzed, the researchers concluded that because delaying TKA in younger patients can result in increased pain and limited ability to function, use of TKA in this age group is warranted. They write that that they found “acceptable survival in our registry of cemented TKA implants of various designs at 14 years.”

Total knee arthroplasties (TKA), or knee replacements, may need to be revised or replaced in some patients due to malfunction of the hardware or other problems. Doctors have noted that patients who understand the reasons for the initial replacement and the revisions tend to have realistic expectations regarding the outcomes than do those who are not better informed. This can extend to the rate of complications and unexpected outcomes, as well.

Studies have been done that looked into the issue of unexpected complications, however, they are most often performed on patients who underwent hip replacements rather than knee replacements. The authors of this study examined the level of understanding the patients had before the surgery and their level of satisfaction with the revision and the reason for the revision.

Researchers contacted 408 patients who had undergone first-time TKA revisions; 238 patients responded and consented to participate in the study. The patients were asked 10 questions about their experience, which covered topics such as the reason why they went for a revision, what they thought the cause for the revision was, if they had been told about any potential complications, how satisfied they were with the pre-operative reaching, the results of their initial replacement surgery, and how long the replacement lasted before they needed the surgery.

The patients’ surgeons were also contacted and were asked the reasons for the revisions. When compiling the data, the researchers included the demographic data, such as age, gender, education, and overall health status.

When reporting the reason for the revision, 38 percent of the patients reported that they were having pain, 25 percent said their knee was unstable, 18 percent said they had an infection, 1 percent experienced a trauma to the knee, and 12 percent had “other reasons.” When the surgeons reported their reasons for the revision, they stated that hardware loosening occurred in 40 percent of patients, bone breakdown and loss in 22 percent, instability of the joint in 12 percent, infection in 12 percent, and unknown diagnosis in 3 percent. When asked if the revision was expected, 37 percent of the patients said that it was no expected, but they did know that it could be a complication. Ten percent said the failure was a manufacturing defect or failure, 8 percent said it was due to trauma, 11 percent blamed the surgeon, and 14 percent said it was unknown.

The researchers confirmed patient expectations were indicative of what the outcome was likely to be. The findings suggested that many patients who underwent the revision surgery did not have realistic expectations, with many believing the revision would last longer than their initial replacement. The surgeons, on the other hand, felt differently. When the patients were asked to rate their satisfaction with the education they received before surgery, only 62 percent were satisfied, 19 percent somewhat satisfied, and 19 percent were not satisfied. However, when asked about their satisfaction about the surgery itself, only 51 percent were satisfied, 12 percent somewhat satisfied, and up to 37 percent were not satisfied. When asked to rate their satisfaction regarding how long the TKA worked, only 44 percent were satisfied, 16 percent somewhat satisfied, and 40 percent were unsatisfied.

There was a marked difference between the patients who had to have a revision within 10 years of the initial replacement and those whose revision lasted longer.

The authors of the study point out that there were some limitations, particularly the small participation group and that the questionnaires were asked about events that had already passed. The authors note that there was a wide discrepency between the patient and surgeon about why the initial surgery failed and why the revision was necessary. They concluded that patient education and counseling needs to be realistic and documented in order to ensure the patients understand the risks and causes of failures.

Treatment of meniscal tears has changed over the years. It was once thought that the meniscus wasn’t really important. The cartilage was removed if it developed a tear. Now surgeons try to save as much of the tissue as possible.

The operation has also changed from an open incision to arthroscopic repair. Arthroscopic repair or partial meniscectomy is now defined as today’s standard of care.

In this article, the authors reviewed past studies done on arthroscopic repair of meniscal tears. The goal was to find trends in results. Factors linked with good and bad results were of particular interest. Each study was evaluated for proper research and statistical methods.

Results of their analysis showed that the type of patient (age, sex) wasn’t strongly linked with results. The type of tear is far more important to the final outcome. For example, flap tears take longer to heal compared with bucket handle tears. Athletes with flap tears return to sports much slower than those with other types of tears.

It doesn’t seem to matter which side of the joint the meniscus is torn on. There was no difference in results for medial (side closest to the other knee) versus lateral (outside half of knee) meniscal tears. The natural anatomical knee alignment and angle may improve the results for some patients.

Measures used to determine results can also yield differences in outcomes. X-rays may show a good outcome but patient satisfaction may be low. And the results of the surgeon’s findings after the operation may not match up with the patient’s symptoms. In other words, exam results can be considered normal when patients are having significant pain or loss of motion.

Overall, arthroscopic partial meniscectomy is a successful procedure for both medial and lateral tears of the meniscus. The results are better if less than half the meniscus is removed. Patients with both a torn anterior cruciate ligament (ACL) and a torn meniscus have the worst results.

These results are based on studies extending as far as 15 years after the surgery. Researchers will continue to follow these patients for 20 years or more to see the long-term effects.

Improved quality and safety of allograft (donor) tissue has made it possible to use this tissue for more knee surgeries. Ligament repair and reconstruction tops the list of common uses for allograft tissue. Repair of the meniscus (knee cartilage) and osteochondral (cartilage to bone interface) are also on the rise.

The use of allografts in knee surgery is the focus of this article. The authors review how the tissue is obtained, sterilized, and stored. Risk factors and incidence of infection are discussed. Nucleic acid testing is used to detect HIV and hepatitis C. Proper sterilization is a must to avoid bacterial infection.

Various groups have been set up to help control the quality and safety of allograft tissues. Regulation of the supply is not completely standardized. Some groups such as the American Association of Tissue Banks (AATB) has standards that are voluntary and not mandatory.

Other groups such as the Musculoskeletal Transplant Foundation (MTF) have high standards for screening and selection of donors. They have a perfect record when it comes to infection. There have been no reported cases of infection in more than two million cases of tissue transplantation.

Autografts (patient’s own tissue) are still best for competitive athletes who want to get back into action. Patients who can benefit the most from allograft tissue for knee surgery include:

Surgery to repair injuries to the knee, especially anterior cruciate ligament (ACL) tears, can lead to loss of motion in the knee called arthrofibrosis.

Too much scar tissue forms inside and around the joint. The result is painful restriction of motion. Even with daily exercise, stretches, and rehab, disabling loss of flexion, extension, or both can occur.

In this article, orthopedic and neurosurgery specialists from the Greenwich Sports and Shoulder Service in Greenwich, Connecticut provide an update on risk factors, pathology, and treatment of knee arthrofibrosis.

Patients with improper graft placement in ACL repairs are affected most often. If the graft tissue is too short or placed too far in one direction (anteromedial), loss of flexion occurs.

Some patients healing process involves the production of too much scar tissue. Tiny adhesions form between the tissues preventing full motion. Loss of motion leads to muscle weakness and atrophy. A painful limp and loss of function may also occur.

The incidence of arthrofibrosis after ACL surgery has declined over the years. Range of motion right after surgery and avoiding prolonged immobilization have helped changed this picture.

When arthrofibrosis does occur, manipulation is advised as early as possible. This is usually between four and 12 weeks of the ACL reconstruction. Anyone who does not achieve 90 degrees of flexion despite daily rehab should consider having a manipulation procedure. Delaying too long can cause further complications.

The authors review manipulation techniques using arthroscopy versus an open method. Whenever possible, the arthroscopic method is used. Arthroscopic manipulation allows the surgeon to assess all areas involved.

Loose fragments of cartilage, tissue, or debris are removed. Saline is injected into the joint to flush it out. Any tight bands of tissue can be released. The surgeon can check for graft impingement. The condition and position of the graft can also be checked and corrected if necessary. Open surgery is only done when closed surgical management has failed.

More studies are needed to assess the long-term results of manipulation for knee arthrofibrosis. Better understanding of the healing process may help prevent excessive scarring in the first place. The surgeon should watch carefully for knee arthrofibrosis in patients with high-energy and multiple ligament injuries.

Chronic dislocation of the patella (knee cap) requires surgery to stabilize the knee. Many surgical procedures have been done to correct this problem. In this study, surgeons in Japan report on the long-term results of a new realignment technique.

Previous reconstruction methods have resulted in patellofemoral osteoarthritis. This painful condition occurred within 10 years of the operation. This study analyzed the long-term results of a new medial patellofemoral ligament (MPFL) reconstruction method.

The authors described in detail their surgical technique. An artificial ligament made of polyester tape was passed through a tunnel drilled through the patella. The surgeon temorarily attached the ligament to the adductor tubercle. The tension of the ligament was tested.

The ligament was stapled to the bone when full knee range of motion was possible with just the right amount of tension. A thin layer of bone was placed over the staples. Patients were placed in a knee immobilizer. Exercises to strengthen the quadriceps muscle were started right away.

Results were measured by motion and function. Outcomes were reported as excellent, good, fair, or poor. Two of the patients had a poor result because the patella dislocated again. Almost half were classified as excellent. Another 42 per cent were ranked as good. The rest (12 per cent) were placed in the fair category.

The presence of patellofemoral osteoarthritis was minimal when present. Two-thirds of the patients had no sign of arthritis at all. These results show that this method of MPFL reconstruction is safe and effective in preventing recurrent patellar dislocation and progression of arthritis.

The authors suggest that even small errors in graft length and position can make a difference. Without the correct tension, increased force and pressure are placed on the patellofemoral cartilage. Patellofemoral osteoarthritis can be prevented after MPFL reconstruction.

There are two ways to implant a knee replacement. The standard method is with an open incision. More recently, computer-aided systems have made it possible to do minimally invasive surgery (MIS). With MIS, a very small incision is made.

There are concerns about the accuracy of implant positioning using the MIS method. In this study, two groups of patients are compared. All patients received a unicompartmental knee arthroplasty (UKA). This is the replacement of just one side of the joint.

One group had the open incision surgery. The second group had the MIS. All surgeries were done by the same experienced knee reconstruction surgeon. X-rays were used to measure angles and orientation of the UKA implant. The results showed no difference in implant accuracy between the two groups. Operating time and rate of complications were also similar.

Long-term studies are still needed to look for any links between limb alignment and long-term survival of the implant. It’s possible that poor implant position will alter limb alignment and result in faster wear and tear.

Some studies have already shown reduced function in patients with malalignment. More studies are needed to compare open versus MIS UKA. Factors to compare include rates of recovery, accuracy of implant position, function, and cost.

In this study, the results for two groups of knee replacement surgery were compared. Patients in both groups were operated on using the smallest incision possible. The first group had a unicompartmental knee arthroplasty UKA). Just the medial side (closest to the other knee) was replaced.

The second group had a total knee replacement (TKR). The surgeon used a computer-assisted minimally invasive surgery (CA-TKR). The incision for the CA-TKR group was slightly longer than for the UKA group. But it was less than the traditional open-incision method for TKR.

Patients in both groups were matched by age, severity of arthritis, gender, and range of motion (as recorded before the operation). Results were measured by comparing a wide range of variables. These included motion, function, and weight-bearing status. Surgical time, length of hospital stay, and costs were also reviewed.

The UKA group had a higher functional score on the Knee Society test given. More patients in the UKA group had full range of motion (120 degrees of knee flexion) compared with the CA-TKR group. Three times as many patients in the UKA group could walk more than one kilometer (0.62 miles).

Hospital stay, total cost, and complications were higher in the CA-TKA group. The authors conclude that computer-assisted technology allows more accurate implant placement. Even so, the overall results aren’t as good as with the UKA. Added cost for more expensive implants, technology, and longer time in the hospital with CA-TKA point to the UKA as a better choice. This is especially true for older patients with medial compartment arthritis.

Chondroitin sulfate (CS) and glucosamine are two nutraceuticals often used by patients with osteoarthritis (OA). Nutraceutical is a new word made by combining two other words: nutrition and pharmaceutical.

Nutraceuticals are supplements that don’t have to meet any quality standards. They can be purchased by anyone over-the-counter. Safety and effectiveness of these products for OA has not been proven.

The authors of this report reviewed the results of five recent meta-analyses. All studies that were included looked at the safety and effectiveness of CS in treating OA. A meta-analysis is done by combining the results of several similar studies. The outcomes are clearer when the data for a number of patients is pooled.

In these five meta-analyses, patients taking CS were compared with patients receiving a placebo (sugar pill) or no treatment. All patients had knee OA. Pain, improved function, and safety were the main measures. One study looked for proof that CS can slow or stop the progress of OA.

Data analyzed from these studies seems to suggest that CS works better when it’s combined with glucosamine. Patients who benefit the most have moderate to severe OA pain. CS combined with glucosamine may be an alternative to non-steroidal antiinflammatory drugs (NSAIDs).

Overall, the evidence is medium. This means studies agree there’s clinical evidence that the product works. But more research may show different findings. For now, the safety of CS is proven. Anyone taking either CS or glucosamine should keep taking it until proven otherwise.

Patients who have a cartilage defect in the knee often undergo correction with either autologous chondrocyte transplantation (ACI) or microfracture. With ACI, cells from the patient’s own cartilage are collected to produce a culture of cartilage cells, which are collected and regenerated for implantation into the cartilage surface. With microfracture, tiny holes are made in the patient’s bone, next to the cartilage defect. Bone marrow seeps out of the holes and creates a blood clot. Cartilage-building cells are then created.

The authors of this study investigated which procedure would produce better results 5 years after surgery. These findings follow 80 patients, 40 treated with microfracture, 40 with ACI. The patients’ cartilage defects were due to trauma (65 percent), osteochondritis dissecans (28 percent), unknown for the rest. The average time since injury had been 36 months and 93 percent of the patients had already had knee surgery before participating in the study.

All patients were available for the 5-year follow up, although some could only participate by questionnaire through the mail or by telephone. The researchers found that 9 patients’ procedures were failures in either group, occurring on average around 26 months after ATC and 39 months after microfracture. One patient in each group in the failure group had a knee replacement. The rest of the patients underwent new cartilage-resurfacing.

The remainder of the patients were assessed with the visual analog pain scale. The majority of patients (72 percent) had less pain compared with before surgery. The majority also reported improvement in range of motion and activity, in both groups. This differs from the 2-year follow up when the microfracture group showed significantly more improvement in some areas than did the ACI group.

At the 2-year follow up, the researchers obtained biopsies from 67 participants. The results showed no significant differences between the two groups in terms of the make-up of the healing tissues.

The authors point out some limitations of the study. These include the inability of the researchers to verify patient compliance with rehabilitation and the lack of a control group.

The failure rate of both procedures appears to be in line with that found in previous studies. While both procedures seem to have the same results, the ACI procedure does involve two steps, the removal of the cells and the re-implantation. The authors conclude that long-term follow up is still needed to determine if one method is superior than the other.

The patella, or kneecap, helps protect the femur and also helps the joint work properly. Because the kneecap is so important, if there are any problems with it, this can affect the way the knee functions and it can cause pain and discomfort. Doctors have found that fractures around the knee replacement, periprosthetic patellar fractures, which include fractures of the femur, may be the most common type of fracture that result in knee replacement complications.

The authors of this article review fractures after knee replacements have been performed, the classification systems used to identify the fractures, and the treatment decisions made by the doctors. They found there was no universal classification that could help doctors categorize the fractures, the type of treatment, and probable outcomes.

Statistics show that periprosthetic fractures occurred in 0.11 percent to 21.4 percent of patients who underwent a knee replacement. Statistics from the Mayo Clinic Joint registry list a rate of 0.68 percent of fractures in 12,000 first time knee replacements that were done over a 13-year period.

It was noted that these fractures happened nine times more often after surgery than during surgery, and more frequently in revision surgeries rather than first-time surgeries, at a rate of 1.8 percent (revision) compared with 0.7 percent (primary).

People who develop a periprosthetic fracture are not always aware of it because such fractures do not always cause pain, although patients who do have pain complain that it is located at the front of the knee, particularly when going up or down stairs. Other signs of a fracture could include weakness or instability of the knee. Many times, the fracture is only found through a routine follow-up x-ray. If the fracture is only discovered when it has been present for a while, usually no treatment is done.

The fractures can happen during or after the knee replacement. During the surgery, they can occur through the surgeon’s handling of the patella, problems during surgery or with the bone itself. AFter surgery, fractures can happen from trauma, such as an accident or stress on the bone.

The researchers found that patients had an increased risk of developing a fracture if they had osteoporosis (thinning of the bones), bone cysts, weak bones, rheumatoid arthritis, and/or increased activity, or if they were men. Previous research did not find a big difference between patients who had rheumatoid arthritis or osteoarthritis, however. As well, there is disagreement as to whether gender does play a role in fractures.

Certain types of replacement design have also played a role in fractures. How the replacement is implanted can place stress on the bones, causing the fractures, particularly after a revision surgery.

How periprosthetic patellar fractures are treated depends on whether the replacement mechanism is still working and intact, how stable the kneecap compartment is, and the quality of the remaining bone. The doctors can choose to treat it conservatively, as one would normally treat a broken bone, or they choose to operate to repair it.

Several studies report varying success with conservative, nonsurgical, treatment and surgery. The authors of this study have found that if a fracture is minimally displaced, the kneecap component is still intact, and the knee is working properly, then conservative treatment, with immobilization at first, has a good outcome. In fact, often surgery did not have a good outcome. However, more involved fractures did require surgery to repair the mechanisms and bones, and to remove fragments if present.

The authors conclude that further research is needed to redefine the best surgical management for these types of fractures.

In this study, patients who had a unicompartmental knee arthroplasty (UKA) were surveyed about their sports and recreational activities. UKA refers to the replacement of just one side of the knee joint. The implant is needed because an uneven wear pattern is causing altered biomechanics and pain.

All patients received a mailed questionnaire 12 to 28 months after their surgery. The survey asked questions about 20 different sports and recreational activities. Frequency, duration, and length of exercise session were assessed before and after surgery. Patients were also asked about pain, motion, and anxiety during sports participation.

The results showed that the majority of patients were involved in regular sports and recreational activities before surgery. The data also showed that older patients were more likely to remain active compared to younger patients.

Most of the patients reported an increased ability to engage in sports activities after UKA compared to before. Hiking, biking, and swimming were the favored activities. Patients were less likely to enjoy high-impact activities such as jogging, tennis, or outdoor sports, especially skiing.

Frequency of activity remained the same before and after surgery. If anything, patients decreased the length of time spent exercising per session. The difference was only about 10 minutes. The overall return to sports rate was 94.8 per cent. Half of these patients were back to their normal activity level within three months’ time. By the end of six months, two-thirds of the group resumed sports and recreational activities. The remaining one-third needed more time (six months) to return to sports.

This study showed that active adults who receive a UKA can and do return safely to sports and recreational activities. Overall satisfaction with the results was good. The surgery maintained or improved sports involvement.

The authors suggest future studies are needed to focus on finding an acceptable level of activity after UKA. Finding ways to remain active without increasing the risk of implant wear and loosening is important for these active patients.

There’s plenty of proof that rupture of the anterior cruciate ligament (ACL) or injury to the meniscus of the knee eventually leads to osteoarthritis (OA). To quote the authors of this report, pain and loss of function in middle-age results in a young patient with an old knee.

What can be done about this? There’s not enough evidence to support the idea that surgery to repair the damage prevents OA. Better understanding of the process of OA after injury might help direct future treatment.

This article gives a review of the literature on the long-term effects of knee injuries. Surgeons from Boston University School of Medicine and Lund University in Sweden discuss the reasons for wide ranging results after treatment.

Trauma resulting in ACL tear is usually very forceful. In fact, it is often enough to also cause injury of the meniscus, joint cartilage, and other ligaments. This may be the number one reason why OA is so common after ACL injury.

Other risk factors for the development of OA after knee injury have been found. These include age, family history, and joint shape. Work and leisure activities, obesity, and muscle weakness also increase the risk. The findings of many studies suggest that OA is the result of a combination of genetic and environmental factors.

Long-term outcomes after knee injury include signs of OA seen on X-rays and MRIs. Painful symptoms and loss of function are typical in over half of all patients with an ACL rupture and/or meniscus tears. This is true whether or not surgery was done to repair the damage.

The authors review in detail the pathologic processes that occur with knee injuries. Changes in the joint cartilage make the joint less able to handle loading.

The injured joint may never return to a normal rate of metabolism, which also affects load and function. In some cases, ligament injury occurs with minor or no apparent trauma and may actually be a part of the OA disease process.

The authors suggest that before changes can be made in the management of knee injuries, better studies are needed. Good quality, long-term trials that evaluate and compare treatment, costs, and report on outcomes are needed in this area.

For a very long time, medicine treated women the same as men. But research has shown over and over that this just is not so. In the case of osteoarthritis (OA), for example, women are more likely to have this condition. And their symptoms are worse. But they don’t get a knee replacement nearly as often as men do.

Differences in OA based on gender is the topic of this article. It’s not clear why treatment is different for women compared with men. Risk factors such as anatomy and genetics may play a role. Previous knee injury may also be an important difference.

But even though women have a thinner patella (knee cap) and thinner knee cartilage, there’s no proof that these things make any difference. Other anatomical differences such as a narrower femur (thighbone) and larger Q-angle of the quadriceps muscle haven’t been linked to gender differences either.

Studies show that women are more likely to have worse symptoms. They have greater disability compared with men who have OA. And even after adjusting for willingness to have surgery, women are still less likely to have a knee or hip replacement.

The reasons for the underuse of joint replacement by women are unknown. More research is needed to understand the whys of gender differences. Until then, the authors suggest much more education must be done to help women get diagnosed and treated sooner.

Full-thickness defects to the cartilage along the bottom of the femur (thighbone) can cause significant pain and loss of function. Treatment often includes debridement, microfracture, and osteochondral autograft.

When these methods don’t work, there is another approach called autologous chondrocyte implantation (ACI). With ACI, the damaged area is cleared of dead cells. The joint surface is smoothed and made ready. A small piece of a bone covering called the periosteum is patched over the hole.

Healthy cartilage is taken from the patient and sent to a lab where five to 10 million new cells are grown from the sample. The new cells are injected under the periosteal patch. They grow and mature and fill in the defect.

ACI can be expensive. The cost of cells can be as much as $25,000. But this method of restoring the joint surface has other cost savings. Patients get back to a high level of function.

Less time in pain and with improved function gained by ACI also affects quality of life. The cost of being out of work or unable to care for the family must be factored in.

Many health care plans see the benefit of ACI and are including this treatment in their plans. ACI may help the most challenging patients who have not benefitted from other treatments for cartilage defects.

Patients with knee injuries such as tearing of the anterior cruciate ligament, or ACL, often undergo surgical repair to regain full motion and use of the knee. Surgeons have used two techniques to do this repair: meniscal allograft transplantation (MAT) and/or autologous chondrocyte implantation (ACI). Research has been done on the procedures done alone, but no reviews have been found of the two procedures being done together.

The meniscus or cartilage in the knee plays several vital roles. It helps joint movement, lubrication, and helps support the joint load, for example. These roles make it so that even the smallest of injuries can affect the knee’s function. Therefore, proper correction is needed to prevent knee problems later on in life.

The authors of this study wanted to evaluate patients who underwent both procedures and review their outcomes. To do this, 48 patients who had undergone both procedures in one or both knees were observed. To be included in the study, the patients had to be followed for two years; of the 48 original patients, only 36 met all the requirements for the study. At the end of the 2 years, 4 patients had what are called “failures” in their knees and required alternative treatment before the two years were up and 3 patients were lost to follow-up, leaving the results for 29 patients to be calculated for the study findings.

The average age of the patients was 36.9 years with a range between 16.1 and 52.1 years, 23 of the patients were men. Patients were evaluated by x-rays at the start of the study and through questionnaires administered before the surgery, 6 months following surgery, 1 year following surgery, and yearly thereafter. The questionnaires used were the Browne modified Clinician Cincinati (objective), the Brown modified Patient Cincinati (subjective), the Lysholm scale, and the Visual Analog Scale (VAS).

Following the surgery and after follow-up, the researchers found that the patients showed significant improvements in all the surveys/questionnaires, including their satisfaction with the surgery’s outcome. The authors point out that 4 patients, not included in the final analysis, did experience failure and needed surgery to correct their problems. These failures occurred at 11, 13, 17, and 23 months.

The authors also point out that there are some weaknesses to the study. They include that many patients have complex problems with the knee that requires more than just the repairs described in this study. Another weakness is the lack of x-rays in follow-up. However, despite the short-comings of the study, the authors suggest that continuing this research in a larger number of patients will reveal the best method of managing these knee injuries.

Surgeons watch carefully to see what kind of wear patterns occur in the various parts of joint replacement implants. In this study, two designs of the tibial (knee) inserts are compared: mobile- and fixed-bearing.

The tibial implant rests on top of the tibial plateau. This is the flat shelf along the top of the lower leg bone. The shelf forms the bottom half of the knee joint.

The mobile-bearing insert rotates (turns) when the knee twists or rotates. This feature is designed to decrease uneven wear. The mobile-bearing knee implant decreases contact stress where pressure is applied to the bearing surface. It also decreases stress where the implant meets the bone.

Despite all these perceived advantages of the mobile-bearing implant, there’s no evidence that this model performs better than the fixed-bearing design. The authors examined the location, amount, and type of wear on tibial implants that were taken out of 51 patients.

A special microscope and computer image system were used to analyze wear patterns. Some of the implants had come loose, broken, or failed because of uneven or excessive wear. The authors describe the various wear patterns in detail.

They found that low-grade wear was seen in the mobile-bearing knees. High-grade wear was more common in fixed-bearing knees. Low-grade refers to a burnished surface or abrasion seen on the surface of the implant. High-grade wear has scratches and pits in the surface. The protective covering can get worn off with high-grade wear.

Fixed-bearing inserts were more likely to be worn all the way through. Some of these implants also had metal debris from other parts of the prosthesis embedded in them. As suspected, the fixed insert had uneven wear.

Overall, the mobile-bearing insert held up much better than the fixed type. In fact, the authors report far fewer mobile-bearing inserts were even removed because of failure. The fixed-bearing were far more likely to fail requiring removal and revision.