News Category: Knee

Patellofemoral pain syndrome (PFPS) is a common cause of knee pain in athletes. Active teens and adults are affected most often. The exact cause of this problem remains under investigation.

Studies have linked hip muscle weakness with PFPS. Weakness of the hip abductor and hip external rotator muscles may be one cause of PFPS. When there’s weakness of these muscles, then there’s too much hip adduction (movement toward the midline) and internal rotation. These motions put increased stress on the patellofemoral joint.

A recent study by a group of physical therapists showed that the Q-angle of the knee in patients with PFPS is increased during dynamic movements. The Q-angle is a measure of the angle between the femur (thigh) and the tibia (lower leg). An increased Q-angle means there is an increased lateral pull (sideways away from the knee) of the quadriceps (thigh) muscle.

In this study, changes in knee alignment during movement were measured and compared between two groups of women. One group had a known PFPS knee problem. But there was no known cause except overuse. The second (control) group did not have any known knee pain or problems.

Pain levels and hip strength were measured and recorded. Motion analysis was done using a video-based motion capture system. This system allows for measurement of hip and knee joint angles, muscle strength, and analysis of kinematics. Kinematic studies show how the position of the joints changes with time.

The women walked down two 20-cm-high steps. Everyone walked at the same rate by using a metronome set at 96 beats per minute. Five practice trials were allowed. Then 10 test trials were performed. The stair-stepping task was chosen because it is a common activity that brings on pain with PFPS.

The results of this study did not support the idea that hip weakness alters leg kinematics resulting in PFPS. At least not while going down stairs at the 96-beats per minute pace.

The women with PFPS did have lower hip muscle strength compared to the control group. So there may be something else going on to explain these findings. It’s not clear if the hip weakness in patients with PFPS is the cause or the result of this condition. The authors suggest further studies to help identify other factors at play.

Knee osteoarthritis (OA) can benefit from exercise to improve proprioception. Proprioception is the awareness of joint position and motion. Loss of muscle strength and damage to the ligaments and joint capsule from OA can reduce proprioception.

In this study, physical therapists from Taiwan study the use of a foot stepping exercise program. The idea behind this approach was to improve knee proprioception and function in adults with OA. The exercises were done sitting down. This is important because proprioceptive training in the standing position can make symptoms worse for patients with knee OA.

A special device called an electrogoniometer was used to measure knee joint position. A special foot pedal was designed that was hooked up to a computer.

A computer game controlled by pressing the foot down on one of four pedals was used. The patients were required to step on the right, left, up down pedals with increasing speed over time. This feature increased the difficulty of the task. All testing was done in the sitting position.

Training sessions lasted 20 minutes per leg. There were three sessions per week for six weeks. An experienced physical therapist supervised each patient. There was a control group of similar patients with OA. The control group did not do the target-matching foot-stepping exercise (TMFSE). No other exercises were done by the control group.

Measures used to assess results included knee reposition error (KRE), walking speed, and function. KRE is a measure of the person’s ability to repeat the same motion at the same pace over several trials. This is a valid measure of joint proprioception.

After the training session, the exercise group could walk faster and go up and down stairs faster than before the program. They could also walk faster than the control group. Walking speed did not change for the control group.

Reposition error was less for the exercise group but unchanged for the control group. Pain and function were also improved in the exercise group but not for the control group.

The results of this study suggest that repeated stepping drills done in the sitting position can benefit patients with knee OA. Proprioceptors in muscles, tendons, and joints are activated with this activity.

Improved knee function is possible with changes in proprioception. When proprioception is improved there may be a decreased risk of falls for this patient population. This training program is a good option for patients who cannot exercise in the standing position.

Should high-level athletes have surgery to repair a ruptured anterior cruciate ligament? If yes, how soon should the operation be done? Is there any benefit in delaying the inevitable?

These are all questions that are put to the test in this study. Physical therapists from the University of Delaware conducted their research in an effort to find a tool to guide patient decision and management after ACL tears.

Based on studies done so far, there isn’t a lot of support for nonoperative care. But there is some evidence that athletes who injure their ACL can resume sports without surgery to repair the damage. Some are even able to play for a full year without any further problems or knee instability.

It would be good to find a way to assess patients and determine who is going to need surgery. Likewise, it’s important to know when to advise athletes to go the nonoperative route. Athletes also need to know what levels of activity won’t increase their risk for further injury. The results of this study may help provide this information.

An algorithm was used to classify patients into rehab versus surgery groups. Algorithm is a decision tree with factors to consider at each step of the process. For example, athletes with ACL tears and full-thickness cartilage tears were not included in the screening process. Their risk of reinjury was too great.

Patients with full knee motion and who could hop on the injured leg without pain went to rehab. If there was swelling, difficulty weight-bearing, or ongoing pain, then physical therapy treatment of the problem was started first before rehab.

Anyone who still had impairment after one month of rehab was referred to the surgeon. Thirty days was considered plenty of time for a performance athlete trying to get back into the game to recover. If problems weren’t taken care of by then, surgery was likely needed.

The screening exam and algorithm presented in this article can help identify rehab candidates after ACL injury. Surgery is needed to return many high-level athletes back to a pre-injury level of play. But it is possible for some athletes to delay surgery with a full rehab program.

These athletes can return to sports without further episodes of knee instability. The results of this study showed that more athletes can rehab and return to their sport without surgery than was previously thought possible.

In part one of this two-part study, researchers from the University of Delaware devised a screening exam and classification algorithm (steps in the decision process). These tools were used to help guide the management of anterior cruciate ligament (ACL) injuries. Active athletes were their target group.

In this study, the same screening exam was tested on a large number (345) of athletes with an ACL injury. It was used to identify factors that separated athletes who needed surgery from those who didn’t. The screening exam includes joint motion, knee laxity, and quadriceps strength. Several tests involving hopping skills were also included. The patient gave a self-report on knee function as well.

Up until now, it has been assumed that knee laxity in the anterior (forward) direction was a good indicator of rehab-versus-surgical candidates. Activity level before the injury was also used to gauge function after surgery. The higher the activity level, the more likely surgery would be needed.

The results of this study bring those guidelines into question. The results showed that simple hop tests and patient surveys about knee function were better predictors of outcome.

Preinjury level of activity was not a reliable way to predict knee stability. In other words, athletes with the highest level of activity were not the ones who needed the surgery. And there was no difference in joint laxity between those who could rehab without surgery and those who needed ACL reconstruction.

This information will help guide the patient and surgeon’s decision about treatment of ACL injuries in the weeks after the trauma occurs. Using the University of Delaware’s screening exam and algorithm makes it easier to identify patients with good potential for recovery without surgery.

Computer technology combined with magnetic resonance imaging (MRI) has changed the way we think about knee osteoarthritis (OA). New models of knee function have been proposed. Better understanding of how muscles work with ligaments to stabilize the knee joint is changing how we treat this problem.

In this review editorial, Dr. Torry summarizes the work of Anderson, Pandy, and Shelburne, well-known names in research of the knee. Specific information is reviewed about how muscle imbalances or weaknesses can affect the load placed on the knee joint.

It is these factors along with the fact that cartilage in the knee joint has no direct blood supply that eventually leads to the damaging effects of OA. Changes in treatment based on this new information have brought two areas into focus.

First, there’s new appreciation for the need to screen patients carefully for treatment. Choosing the right patients for surgery can help ensure good results. New ways to surgically treat chondral defects of the knee have made it possible to repair and restore joint cartilage. Chondral refers to the interface of the cartilage with the first layer of bone under the cartilage in the knee.

And secondly, the role of physical therapy for patients with knee OA has been highlighted. Finding ways to reduce load on the knee and preventing the progression of OA is the focus of much of today’s research efforts.

Autologous chondrocyte implantation (ACI) is a way to surgically treat full-thickness tears of the knee joint cartilage. Knee function can be restored or improved with this procedure, especially for athletes who might otherwise be out of the game.

Normal cartilage cells are taken from the patient and grown in a laboratory setting. When the cells have multiplied by 20 to 30 times, then they can be reimplanted into the damaged area. Healing and remodeling of the articular cartilage occur over a period of weeks to months.

In this article, physical therapists at the University of Colorado Health Sciences Center (UCHSC) present their rehab protocol for this procedure. They provide a review of the technique and results from other studies. There’s no proof that this technique works better than other methods such as microfracture. Overall, the results have been good to excellent.

Proper rehabilitation is important to promote healing and prevent damage to the implantation. Overload and shear forces can damage the new tissue if they occur too soon in the postoperative period.

The UCHSC protocol is similar to programs used at other institutions. One difference may be that the patient is not allowed to put any weight on the knee for the first six weeks. This is especially important for patients whose lesion comes in contact with the other side of the joint at the point of near knee extension.

Goals and steps in the rehab process are outlined through four phases including:

Knee joint replacement is not the only way to treat joint degeneration and pain from osteoarthritis. Other surgical options are now available. In this review article, the basic science, pros and cons, and use of microfracture are presented.

Microfracture refers to a surgical technique that involves making tiny holes through the joint cartilage and subchondral bone. Subchondral refers to the layer of bone underneath the cartilage.

The puncture goes all the way through to the bone marrow. A small amount of bleeding occurs as bone marrow seeps into the hole. Holes are drilled around an area of cartilage defect. Then holes are spaced carefully through the defect. Too many holes too close together can result in less than ideal healing of the cartilage.

Success of the microfracture technique depends on the rehab program afterwards. Healing requires an environment that ensures the marrow clot will mature into repair tissue and fill in the defect. The authors present two specific rehab programs.

The first rehab protocol is for lesions on the femoral condyle or tibial plateau. The femoral condyle is the round end of the femur (thigh bone) that attaches to the tibia (lower leg bone). The tibial plateau is the flat part at the top of the tibia. The femoral condyle rests on the tibial plateau to form the knee joint.

The second rehab program is for lesions of the patellofemoral joint. This is where the patella (knee cap) moves up and down over the femur during knee motion. Each rehab program is broken down into several phases.

During the first phase, joint motion is restored while protecting the marrow clot. Continuous passive motion (CPM) is maintained with a special machine. Patients are only allowed to touch the foot to the floor for the first eight weeks. They cannot put any weight on that foot.

The program progresses through a strengthening phase then endurance phase. These two phases are followed up with a performance phase. This final phase is for those patients who are athletes trying to return to their sport.

The rehab program for patellofemoral lesions is slightly different. Bracing is used during the first eight weeks after surgery. The knee is only allowed to bend through the first part of the joint range of motion (from zero to 20 degrees of flexion). Details of CPM use for all patients are provided by the authors.

Results of microfracture treatment are reviewed and summarized for several studies published between 1994 and 2003. Follow-up was between two and five years. It appears that weight-bearing too soon and not keeping the joint moving after surgery are major factors in cases that had a poor result.

To ensure success, patients must be chosen carefully for the microfracture technique. Follow-up during rehab is essential for the best results. Further studies are needed to identify the best rehab program for patients who are treated with microfracture.

Physical therapists are key members of the rehab team for patients receiving a total knee replacement (TKR). Helping patients improve quickly and recover function are the overall goals of therapy. Knowing what to expect helps patients judge their progress.

In this study, patterns of change in lower extremity function are measured after TKR. Previous studies have shown that most of the improvements in walking speed and distance occur in the first nine weeks after surgery. How long it takes to reach maximum function is unknown.

Therapists used two common tests of function to measure progress in 84 patients with TKRs. The tests included the Six-Minute Walk Test (6MWT) and the Lower Extremity Functional Scale (LEFS). The tests were given before and after surgery. Patients were followed for one year.

The results of this study showed that patients with higher test scores (meaning better function) before surgery had the best function afterward. The pattern of change was for maximal improvement in the first 12 weeks after TKA. Gradual improvement continued up to 26 weeks. Most of the recovery took place in the first six months.

The authors suggest that TKR patients need close follow-up during the first six weeks to six months after surgery. Any further improvements after six months are small and may not justify the expense of further rehab.

Physical therapists can use this information to help patients set realistic short-term goals. Using the 6MWT and LEFS tests can help identify patients’ specific needs, guide treatment, and predict outcome.

Inside the knee there are two major ligaments that criss-cross each other to hold the knee in place. These are the anterior cruciate ligament (ACL) and the posterior cruciate ligament (PCL).

Injuries of the ACL are common and treatment for this problem is well known. Less often, the PCL is torn or ruptured requiring evaluation and treatment. In this article, the anatomy, function, and changes that occur when the PCL is damaged are presented. Testing and treatment are also included.

The PCL has a stabilizing force on the knee joint. It helps hold the tibia (lower leg bone) in place and keeps it from sliding backwards. This movement is called posterior translation. The most common cause of PCL tears is trauma. A high-energy force against the knee during a car accident or sporting event is often reported.

Diagnosing PCL insufficiency can be challenging. The patient often doesn’t remember the injury. Symptoms are vague. There may be mild knee pain and stiffness. In the acute phase, the pain is in the back of the knee. Later, there can be pain in the front of the knee.

The physician relies on the history, exam, and specific tests to make the diagnosis. X-rays and MRIs are more helpful in the acute stage. There are also several clinical tests that can be done to look for PCL involvement.

The posterior drawer test is used most often. The posterior sag test and the quadriceps active test are also used. All three tests are described in detail. Additional tests may be needed if there are other soft tissues that have been disrupted. The examiner uses the uninjured knee as a guide when conducting each test.

Treatment for low-grade PCL injuries is nonoperative. Bracing, physical therapy, and time are the main management tools. If the symptoms do not resolve or if there’s a high-grade injury, then surgery may be needed. The goal of surgery is to stabilize the knee and reduce joint laxity (looseness).

Research is ongoing trying to find the best surgical technique for PCL repair or reconstruction. Results with current methods have been less than satisfactory.

Long-term studies are needed to see if surgery even makes a difference 10 or 20 years later. It may be that a rehab program is all that’s needed to restore PCL function and knee stability.

The use of unicompartmental knee arthroplasty, or partial knee replacement, is still being studied in terms of effectiveness of result compared with total athroplasties. As surgeons become more familiar with the techniques and as techniques and prosthetic designs improve, implant success grows.

One of the issues with partial replacements is the actual design of the implant to improve the range of motion of the joint. The authors of this study wanted to examine the alignment of the knee after surgery and insertion of the medial compartment Oxford implant (introduced in 1987 as a phase 2 implant), how well the implant survives, and how and when the implant did fail.

The researchers reviewed the records of 55 implants performed in 51 patients – 4 of whom had bilateral or double knee replacements. The patients’ average age was 64 years old and the average weight was 78.1 kg. The patients were assessed through the use of x-rays of the knees and the Knee Society clinical scoring instrument. The two scales, a knee score and a function score, are based on a score of 100 and the higher the number, the better the score. Before surgery, the 55 knees were scored on average of 43 for the knee score and 56 for the function score. After surgery, the average scores were 75 and 90, respectively.

The alignment of the joint was also assessed before surgery. The researchers found that the overall alignment was restored to neutral.

Failure of the joint was limited to seven knees, six of which went on to have total knee replacements. The main reason for the failure was progression of arthritis and not the implant itself (five knees). One knee had loosening, which occurred over three years after surgery. No failures were due to wear and tear of the polyethylene make-up of the implant.

The authors conclude that any failure of this particular implant was due to the progression of arthritis and not the implant itself.

The main treatment for acute flare-ups of osteoarthritis (OA) of the knee is rest, ice or cold compresses, and nonsteroidal antiinflammatory drugs (NSAIDs). NSAIDs work well because they provide pain relief and reduce swelling and inflammation.

But NSAIDs cause unpleasant side effects in some patients. Gastrointestinal bleeding is one of those complications that can be very serious. Researchers are looking for different ways to administer NSAIDs for the most effective treatment.

In this study, tenoxicam (an NSAID) was either taken orally or given as an injection directly into the knee joint. All patients included had an acute flare-up of synovitis in the knee. Synovitis is an inflammation of the membrane that lines the knee joint. Knee pain and joint swelling occur.

First, the surgeon inserted a long, thin needle into the knee joint and aspirated (removed) the fluid in the knee. For the group who received an intraarticular injection, the same needle was used to deliver the drug.

Pain, joint motion, and number of repeat flare-ups were used as the measures of treatment success. They found that the injection group got faster pain relief and had fewer flare ups compared to the group who received the oral type of tenoxicam.

The authors report that tenoxicam may be the safest NSAID to use for intra-articular injection. The high concentration of NSAID in the joint works better and faster than taking the oral (systemic) doses. With fewer flare-ups, patients in the injection group also had greater function and mobility at the end of a year.

Patients with an infected joint after total knee replacement (TKR) need treatment as quickly and as effectively as possible. The consequences of implant and/or joint infection can be very serious. The surgeon does everything possible to save the implant, the knee, and the patient.

In this report, surgeons from the University of Queensland in Australia discuss the use of using polymethyl methacrylate (PMMA) spacers in such patients.

Once an infection is discovered, the implant is removed. The joint is cleaned and rinsed thoroughly of all bacteria. This step is called debridement. Then the joint is treated directly with antibiotics. A special device called a spacer coated with antibiotics is put in the space left by the removed implant.

Using a spacer has several advantages. It holds the soft tissues at just the right tension until the implant can be put back in the joint. Static spacers do not move or allow joint motion. The patient can’t put weight on this type of spacer. It’s possible the spacer can crush some of the bone.

But a static spacer is better than no spacer at all. It keeps the space from filling in with dense scar tissue. The next step up is an articulating PMMA spacer. This type allows for controlled motion of the knee. It holds the space open, keeping a normal amount of tension and balance between the bones, muscles, and ligaments.

There are different methods used for implant removal, debridement, and reimplantation. The surgeon may sterilize the original implant, coat it with antibiotics, and put it back into the joint.

Or a custom-made PMMA spacer is constructed right in the operating room. The surgeon can use the most effective antibiotic for the type of bacteria present. A polyethylene (plastic) liner between the bone and implant is another option. It can be cemented in place with PMMA filled with antibiotics.

Using these techniques, the infection can be controlled. It is also possible to keep the infection from coming back using the PMMA spacers. Using a spacer is a two-stage method of treatment. When the infection is cleared up, then the spacer can be removed and replaced with another implant. This final step is called exchange arthroplasty.

Thanks to the increased use of arthroscopy of the knee, we now know that lesions to the joint cartilage are common. Arthroscopy is the use of a long, thin needle with a tiny TV camera on the end. It is inserted inside a joint and transmits a visual image on a computer screen.

High-impact sports that load the joints can lead to damage of the articular cartilage. This type of cartilage provides a smooth surface for joint motion.

Micro-trauma or injury can cause defects in the smooth surface. At first the cartilage loses volume and stiffness. This is called chondropenia. Chondropenia can progress to cartilage breakdown. This occurs when there are other soft tissue injuries to the ligaments or meniscus at the same time.

Without treatment, deterioration of the articular cartilage can lead to osteoarthritis (OA). There are several new treatment options for cartilage including repair or replacement.

Stem cells have been used to repair cartilage defects. The surgeon uses a small surgical awl (ice pick) to make tiny holes in the cartilage down to the bone. The procedure is called microfracture. It stimulates the bone marrow to form stem cells. Stem cells can then become cartilage or bone.

Microfracture works well when the lesion is small. But there are some concerns that the new cells aren’t true articular cartilage. And the repair may not hold up over time. For this reason, scientists are looking for ways to replace, rather than repair, the damaged tissue.

Mosaicplasty is one method of cartilage replacement. Small plugs of cartilage and bone are harvested from the patient. These plugs are then transplanted to fill in the defect. Medium sized defects are treated with this method. The size depends on how much tissue can be taken safely from the donor site without causing donor site problems.

Large defects can be treated with autologous chondrocyte implantation (ACI). Normal, healthy cartilage cells are removed and taken to a lab where they are reproduced. When there are enough cells, they can be transplanted back into the damaged area.

ACI can be used in younger patients (ages 15 to 55) who are not obese. The lesion must be less than eight millimeters deep. Bone grafting may be needed for defects deeper than eight millimeters.

Studies show good-to-excellent results with ACI. Some long-term studies (up to 11 years after ACI) continue to show that results are maintained. Many athletes are able to return to their previous level of competitive play.

Current research efforts are centered on improving the chondrocyte cover. After an ACI is done, a thin layer of cells is placed over the transplanted tissue. But sometimes the tissue reproduces too many of the wrong kind of cells. This can cause problems.

The next step is to find a way to place a matrix (layer) of cells directly over the defect. The matrix method would eliminate the need for transplantation of healthy chondrocytes. The goal is to find the right kind of matrix material to fill in without overflowing the defect.

The need for total knee arthroplasty (TKA), replacement, is growing for both older and younger patients – and with this growth, physicians need to understand the reasons behind the epidemiology (age and distribution of who is receiving the replacements), the use of partial versus total replacements, and surgical procedures. The author of this article reviews the latest research regarding how the procedure is changing and what may be coming in the future.

In the United States, the use of knee arthroplasty has grown considerably since 1971. Researchers found there was an over 400 percent increase of TKA between those done in the period between 1971 to 1975 and 2000 to 2003 – with the largest increase being in the younger patients, those under 55 years old. This compares with the rise of total hip replacements of only 55 percent. More women required TKA than did men except for older patients over the age of 80 years. The researchers also found that the reasons for TKAs changed: during the period in the 70s, 51 percent of TKAs were done for osteoarthritis, in the 2000s, this rose to 92 percent. Forecasts estimate that the number of first time TKAs (primary TKAs) will increase from 450,400 to 3.48 million by the year 2030, while there will only be an increase from 208,600 hip replacements to 572,100.

When looking at the actual treatments, the researchers found that unicompartmental knee arthritis (arthritis in one section of the knee) requiring only partial knee replacement, were frequently in younger patients. One study reviewed by the author of this article found that there was a better outcome for patients who underwent a procedure that involved metal-backed components over all-polyethylene tibial (shin bone) components. They found more complications associated with the second type, as well. When looking at how the surgery was performed, traditionally or minimally invasive, the patients who had the minimally invasive approach were found to have a better range of motion up to 3 years following the surgery. Another study of the same techniques (traditional vs. minimally invasive) found there were more complications with the minimally invasive approach. These patients experienced problems that required revisions to the knees at a higher rate than those who had the traditional surgery.

Another procedure, the patellofemoral arthroplasty (where the femur and the kneecap join), is being performed more often. This procedure appears to be successful and patients are doing well.

Computers are making their presence felt in the operating room as part of the TKA process. Using computers, surgeons have tried to improve on their ability to line up the limbs more accurately. However, surgery time was increased with the computer (by 27 minutes), as well as the need for blood transfusions.

Techniques during surgery also play a role in patient outcome. In one study, patients received, during surgery, a combination of 3 medications: ropivacaine, ketorolac, and epinephrine, directly into the knee. One day after surgery, they received ropivacaine into the knee again. These patients, who received morphine for pain relief as needed, were compared with patients who had morphine only. The patients in the first group had no complications due to the medication. They also needed less morphine than the control group, although there were no significant differences between the two groups regarding when they were discharged from hospital and how well they functioned.

Other pain strategies studied were the use of cold compression, and extended-release morphine epidural injections. Addressing the blood loss, research has been done evaluating the efficacy of administering medications to lower the risk of anemia and the need for blood transfusions.

Deep vein thromboembolism (blood clot in the vein) is a problem that affects some patients who have undergone a TKA. One study investigated the use of heparin (a blood thinner) to prevent such a clot, rather than after a clot has been detected. Although the complication rate was not high, there was a subgroup of patients who had a higher risk of developing an infection and bleeding complications.

Follow-up results and complication rates are also of interest when looking at the various treatments available. Of particular importance are vthe results of patients who are younger, those under 55 years. Among 1008 patients in one study (over and under 55), the 15-year survival rate was 97 percent for a cemented cruciate-retaining modular condylar total knee replacement, with component removal for mechanical failure, and 98 percent with component removal for aseptic loosening. Patients under 60 years, however, had a lower success rate, according to another study. In a study of primary knee arthroplasties with constrained components. This method has mostly good to excellent results, with a 10-year survival rate of 96 percent. When evaluating TKAs with posterior ligament cruciate ligament recession or excision in conjunction with a conforming polyethylene tray, researchers found and average duration of 8 years, and a survivorship of 95 percent.

The authors also looked at the nationwide Finnish Athroplasty Registry to examine the rates for revisions of TKA. The most common reasons for revisions include loosening and patellar complications, at 32 percent each. These revisions lasted 2 years in 95 percent, 5 years in 89 percent, and 10 years in 79 percent.

Complications associated with TKAs include patellofemoral complications but this seems to be decreasing as awareness grows regarding the rotation and positioning, and design, of the implant.

Studies show that the anterior cruciate ligament (ACL) is not a single-bundle ligament. Instead, it has two bundles: the anteromedial bundle and the posterolateral bundle.

Each of these bundles has its own unique function. Together, they keep the knee stable during weight-bearing and pivoting activities. In this study, special computer-assisted navigation technology was used to measure how each bundle works to stabilize the knee joint during motion.

Each patient included in the study had a two-bundle, four-tunnel technique for ACL repair. The surgeon used computer-aided navigation to perform the procedure. Details of the operative technique are described. Location of the tunnels for each of the bundles was also described.

Computer software used in the study allowed for measurement of rotation and translation of the tibia (lower leg bone). An optical sensor recorded motion during three special tests.

Tests included the anterior drawer test, the pivot-shift test, and the Lachman test. These tests are performed by the surgeon or examiner. They are used to look for knee instability. The authors report the following findings:

Knee injuries can be very complex to treat. This is especially true when there is damage to the surface of the bone. The layer of cartilage in contact with the bone is torn away from the bone. Sometimes even a piece of bone pulls away with it. This is called a full-thickness lesion.

Surgeons are trying to find the best way to treat this type of injury. The cartilage doesn’t have its own blood supply. For this reason, healing is often slow or doesn’t happen at all even with intervention.

In this study, orthopedic surgeons from Italy report on the use of autologous osteochondral grafts to treat this problem. Autologous means the patient uses tissue from some other part of his or her own body. Osteochondral refers to the cartilage just above the bone that lines the joint surface.

The procedure is described in detail. First the damaged area was prepared for the graft. All loose or torn tissue was removed. The remaining surface was smoothed down. Tiny holes were dilled in the chondral surface. Osteochondral grafts were harvested from the donor site.

The plugs of graft bone were placed inside the holes. Once again, the surface is smoothed over. Each patient’s defect was completely repaired.
Everyone was examined every year for seven years. The mid- to long-term results were very good for three-fourths of the patients.

MRIs were used to look at how well the graft took hold in the host bone. About 60 per cent of the patients still had a successful cartilage graft after seven years. There was one down side in the final outcomes. Some of the patients had to reduce or limit their level of sports activity.

The authors reported that smaller lesions requiring fewer osteochondral plugs had the best results. These patients were more likely to return to their previous level of sports activity. Using larger plugs decreased the amount of fibrous tissue filling and subsequent problems.

In this article, researchers from Japan report on the effects of harvesting bone plugs from the knee to treat a problem in the elbow. The patients were all competitive athletes. They had an elbow condition called osteochondritis dissecans (OCD).

Young gymnasts and overhand athletes are at risk for this condition. Most of the patients in this study were baseball pitchers. Forceful and repeated actions strain the immature surface of the outer part of the elbow joint.

The bone under the joint surface weakens and becomes injured. This causes damage to the blood vessels going to the bone. A loss of blood flow to the elbow causes a small section of the bone to die and break off.

Successful treatment involves taking bone plugs from healthy bone and transplanting them to the damaged and dying area of bone. The procedure is called mosaicplasty.

But what is the effect of this procedure on the knee where the donor bone comes from? MRI findings and tests of knee function were used to find out.

In all cases, the athletes returned to their previous level of sports participation. There were no donor site problems. MRIs of the donor site showed the defect filled in with fibrous tissue. There was no edema of the bone marrow or other changes seen on MRIs at the donor site.

The authors conclude there is no harm harvesting bone from a less weight bearing area of the knee to use in the elbow for OCD. Symptoms, function, and healing of the donor site are not a problem at the end of 12 months. Long-term studies are still needed to see if degeneration or other problems occur later in the donor knee.

The use of cementless total knee arthroplasties (TKAs) is appealing because of the many advantages, however, cementless approaches also have some drawbacks, including a higher rate of loosening that will require revision surgery later on. In the late 1980s, surgeons tried to combine the advantages of both cemented and uncemented TKAs with a hybrid TKA; the femoral, or thigh bone, part was cementless while the tibial, or shin bone, part was cemented. Unfortunately, despite early reports of success, longer term follow up is finding that the hybrid TKAs have a higher than acceptable failure rate.

The authors of this study studied the records of 57 patients who had, in total, 65 TKAs with the hybrid approach. The average age of the patients was 60 years, ranging from 27 to 83 years. The diagnoses for the knees were primary osteoarthritis (46), posttraumatic arthritis (8), rheumatoid arthritis (6), osteonecrosis (2),and other causes (3). One criteria to participate in this study was the patients’ bones had to still have good quality of the femur. The patients were followed for an average of 15 years.

Patient function was measured with the Knee Society Scores, out of 100, with 100 being the best score possible. Before surgery, the average functional score was 38. This increased to an average of 86 at the last follow-up. When the patients were asked to rate their pain as mild, moderate, or severe, 18 percent said it was mild before surgery, 40 percent moderate, and 42 percent severe. At the latest follow-up, 54 percent rated the pain as mild, 34 percent moderate, and 12 percent severe. When doing stairs, after surgery at
latest follow-up, 92 percent of the patients were able to climb stairs and 91 percent could get out of a chair without difficulty.

Revision surgery was needed in 27 percent (18 knees). Eleven of these were related to the femur: five for failure of the bone to grown into the implant, four due to loosening and osteolysis from wear, and two because the femoral components had fractured. On the patellofemoral side, four revisions were done. Three other revisions were performed because of wear to the implant and destruction of the bone.

The statistics showed that the overall implant survival was an estimated average of 89 percent at 5 years, 82 percent at 10 years, 64 percent at 15 years, and 58 percent at 17.5 years. This, the authors say, is an unacceptably high rate of failure, leading their institution to stop performing the procedure.

In a certain group of adults, the patella (knee cap) dislocates every time the knee is bent or flexed. Over time, this causes a condition called chondromalacia. Chondromalacia is a softening and shredding of the cartilage behind the patella. Uneven wear and tear in this area can cause painful knee symptoms.

Surgery may be needed to correct the chronic dislocation problem. But realignment procedures may not be enough when there’s chondromalacia present. In this study, surgeons from Taiwan explored the use of several surgical procedures combined together to treat this condition.

Three operations were performed over a period of months to years. The first was a lateral release. The surgeon cut through the connective tissue along the outer edge of the patella.

The second was a medial retinaculum advancement. The connective tissue along the inside edge of the patella was cut and moved. It was sutured (stitched) alongside the patellar tendon.

The final step was an anteromedial tibial tubercle transfer procedure. The tibial tubercle, a bump of bone along the front of the tibia (lower leg bone) just below the patella, was removed and readjusted in location. Together, these operations made it possible to bend the knee past 90-degrees without dislocating.

Everyone wore a knee brace for six weeks after the operation. The brace did not limit motion. Patients used crutches to reduce weight-bearing until healing was well underway. Results were measured using X-rays to look at placement. Tests of knee function were also included.

All patients were able to bend and straighten the knee without further dislocation. X-rays showed major improvement in the angles measured before and after surgery. Function improved dramatically. No one had any further patellar dislocations even with full knee flexion.

Total knee replacement (TKR) is designed to reduce pain while also improving motion and function. Some patients have significant joint stiffness after the operation. In this article, orthopedic surgeons review ways to prevent and treat this problem.

As Ben Franklin once said, An ounce of prevention is worth a pound of cure. In the case of joint stiffness after TKR, it is much better to avoid the problem than try to treat it. That’s been the experience of many patients and surgeons faced with this complication.

Prevention begins by recognizing risk factors. Patients with poor motion before surgery are not as likely to have a good result. Likewise, poor motion when under the effects of anesthesia during the operation is also a negative prognostic sign.

Anticoagulants (blood thinners) are routinely prescribed for all joint replacement patients. The goal is to prevent blood clots. Some studies show that patients taking a particular blood thinner (coumadin) have a higher rate of joint stiffness. Those patients who were taking low molecular weight (LMW) heparin have better results.

The problem of stiffness after TKR may be multifactorial. The patient must follow the pre-operative and postoperative rehab programs carefully. The surgeon must pay attention to the position of the kneecap and balance the soft tissue structures on both sides of the joint.

Using the right implant size for the individual patient is also important. Once joint stiffness occurs, it is often resistant to treatment. Surgery to manipulate the joint may be needed but the results are often disappointing.

Patients, surgeons, and rehab specialists must work together to prevent the problem of stiffness after TKR. A similar effort is needed when stiffness does occur. Surgical technique is important but not all factors are within the surgeon’s control. Patients must be compliant with their prescribed program. This is often difficult when there is pain involved.