Infection After ACL Tendon Graft: What’s the Risk?

The likelihood of a patient with a hamstring autograft having a deep infection after a hamstring autograft for the reconstruction of an anterior cruciate ligament (ACL) is 8.24 times higher than for someone receiving a bone-patellar tendon-bone (BPTB) autograft.

These are the results of a very large study from well-known and respected institution: Kaiser Permanente in California. Almost 11,000 patients from the Kaiser Permanente ACLR registry were involved in the study. These patients were treated in 41 different medical centers in six different geographical regions.

By reviewing the patient records, they were able to determine how many patients who had any kind of ACL graft surgery developed an infection afterwards.

The three main types of ACL grafts included: 1) hamstring autograft, 2) bone-patellar tendon-bone (BPTB) autograft, and 3) allograft. An autograft refers to tendon material taken from the patient and used to replace the torn ligament. An allograft is tendon graft material from a donor bank.

Although the overall infection rate was low (0.48 per cent), the fact that there was an obvious and statistically important difference between the autografts is very significant. In more simpler terms: graft choice does make a difference. There was no apparent difference in the infection rates between autografts and allografts. These findings support (agree with) other previous studies but now provide the added information of how often this happens.

Some additional details from the study also included the fact that there was a 2:1 ratio of deep (deep soft tissue or joint) to superficial (skin only) infections. The superficial infections occurred early on (first month after surgery). Deep infections were more likely to develop up to one year after the procedure.

Further analysis of all the data also revealed that in most cases, hamstring tendon grafts were the source of both superficial and deep infections. Staphylococcus bacteria accounted for half of the deep and three-fourths of the superficial infections. More obese patients (higher body mass index) had a greater chance of developing a superficial infection. The reason for this is unknown but may be linked with the need to remove more soft tissue in larger patients.

What is behind this observed increase in superficial and deep infections associated with hamstring tendon grafts used for ACL reconstruction? There may be more than one possible avenue for this occurence. The authors suggest the following possibilities:

  • The graft tissue is contaminated during the harvest procedure.
  • The graft tissue is contaminated after harvest but while it is being prepared for use.
  • Hamstring tendon grafts take longer to prepare giving more time for possible contamination during graft preparation.
  • Hamstring grafts require the use of a multifilament suture, which could be the source of the bacteria.
  • If the graft or hardware used to fix the graft in place comes in contact with the skin, then contamination is more likely.
  • The tools (e.g., screwdriver) used to insert the screws that hold the graft in place could be an external (environmental) source of contamination.

    The purpose of this study was not to identify risk factors for infection after ACL reconstruction. The authors’ intent was to determine the incidence of such infections and that was accomplished successfully. They suggest future studies to evaluate the many possible risk factors and determine the source and cause of infections. Although the infection rate is fairly low, the results of infections can be devastating to the patient. Preventing infections is still an important goal.

  • Diagnosing and Managing Cysts in the Knee

    Four distinct types of cysts can form in and around the knee requiring medical evaluation and treatment. In this article, surgeons from the New York University Hospital for Joint Diseases in New York City provide a detailed presentation of each one. Background, clinical presentation, differential diagnosis, evaluation, and management are included for each one.

    A cyst is defined as an abnormal closed, bladderlike sac (membrane) containing fluid, semifluid, or semisolid matter. The four most common cysts found associated with the knee are popliteal (Baker) cysts, meniscal cysts, proximal tibiofibular joint cysts, and cruciate ligament ganglion cysts. The fluid usually comes from a channel (pathway or connection) between the synovial fluid inside the joint and the cyst.

    Each of these cysts may have a unique cause and formation but the clinical presentation is usually swelling with limited knee motion. Patient history is important. For example, a previous knee injury or known trauma to the knee cartilage (e.g., meniscus) or any of the knee ligaments has been linked with meniscal cysts.

    The patient may or may not have knee pain. When pain is present, it is usually confined to the joint line, which aids the examiner in looking for the cause. Sometimes, there is a palpable mass but more often a distinct entity cannot be felt outside of the joint. If the cyst causes meniscal degeneration or erodes the bone, knee instability may be present.

    Because knee swelling can be a symptom of bursitis, tumors, blood clots, hematomas, and aneurysms (or other vascular problems), it cannot be assumed that the problem is a cyst. Clinical tests specific for each type of cysts may be performed. But the final diagnosis often requires special tests. Diagnostic tests available to the physician include X-rays, arteriography, ultrasound, CT scans, or MRIs. The pros and cons of each test procedure are reviewed for each type of cyst. Examples of each type of imaging study used to diagnose different types of cysts are presented.

    Cysts can be very benign (do not cause serious problems) and self-limiting (go away without treatment). But more often, they cause enough symptoms that treatment is required. Arthroscopic surgery may be needed to remove the cyst, end the connection between the cysts and the joint, and repair damage to the knee. In some cases, invasive surgery can be avoided. The physician can aspirate (use a needle to withdraw the fluid) the cyst.

    The prognosis for most knee cysts is good. With aspiration or surgical removal, most cysts do not recur. The key to good recovery is an accurate diagnosis. Management depends on the type of cyst and of course, making sure there isn’t a more serious underlying problem (e.g., tumor). The diagnosis can be very challenging. The detailed information in this article differentiating one cyst from another will aid the physician.

    What to Expect After Repeated Knee Surgeries for Anterior Cruciate Ligament

    So many people in this country are having anterior cruciate ligament (ACL) surgery, it’s beginning to seem like a common place problem/solution. ACL ruptures haven’t reached epidemic proportions but with 200,000 cases reported each year, it is a significant problem.

    Surgery to reconstruct the torn ligament is quite successful. But studies do show up to a 10 per cent failure rate after the primary (first) surgery. In this report, surgeons from the Mayo Clinic in Rochester, Minnesota tell us about the results for patients who have two or more ACL surgeries.

    Repeat or revision surgery for ACL reconstruction is often needed because the tunnels drilled through the femur (thigh bone) for the graft tissue to go through are placed too far forward the first time. In other cases, damage to the cartilage on the surface of the knee joint and misalignment of the lower extremity contribute to failure of the primary (first graft) procedure.

    Looking back over the records of patients who had at least two ACL reconstructions at the Mayo Clinic, they found a total of 15 charts. The patients ranged in ages from 18 up to 57. Two-thirds of those cases required new femoral tunnels. Two-thirds had severe chondral (cartilage) lesions. And three-fourths had a meniscal tear.

    As it turned out, the first two factors (placement of the femoral tunnels and chondral lesions) were risk factors for graft reconstruction failure. The third factor (damaged meniscal cartilage) was not directly linked with graft failures. A graft failure was defined as a rupture of the graft tissue or knee joint instability. Another risk factor for a failed ACL reconstruction is obesity. Patients with a body mass index (BMI) measure of 29 or higher had fair to poor results after the first surgery.

    The authors readily admit that ACL revision of primary reconstructions can be a difficult and challenging surgery. There are many factors to consider including a limited choice of graft tissue, fixing the graft in place to create a stable response, unusual/unnatural anatomy, and difficulty finding the right spot and then creating correct tunnels for the final step of the initial surgery.

    Patients also have high expectations, especially when they are athletes hoping to return to their sport equal to (if not better than) before surgery. Many of these ACL injuries (and re-ruptures after surgery) occur in high-demand sports athletes. As the results of this study showed, trauma and overuse lead to recurrent instability most often in this patient population.

    But good-to-excellent results are possible even after repeated ACL surgical revisions. These outcomes were measured using clinical tests (e.g., pivot-shoft test, Lachman score, International Knee Documentation Committee scores), X-rays, and level of function in activities of daily living (ADLs) and recreational/sports activities. Details of revision surgical techniques used are included in the article for surgeon who may be interested.

    In conclusion, although this was a small study (only 15 patients), the results did provide some valuable insight into the risk factors for re-rupture and need for surgical revision after a primary ACL reconstruction surgery. Despite good clinical results, patients reported a reduction in their activity level after repeated surgeries. Most of the time, this was because they chose to restrict sports participation.

    How Meniscus Tears Affects the Knee Over Time

    As more and more aging Baby Boomers start to develop knee osteoarthritis, researchers are focusing on the whys and wherefores of this condition. Studies have already shown that removing a torn meniscus (knee cartilage) puts patients at a significantly greater risk of developing knee osteoarthritis later on.

    But what happens to those patients who have a torn meniscus that doesn’t get treated? Can the untreated injury also contribute to knee the development of knee osteoarthritis? That is what this study proposed to find out. They used a knee osteoarthritis database called the Knee Osteoarthritis Initiative (OAI). This database contains information collected on patients between the ages of 45 and 80 years of age who were treated at one of four participating centers.

    The idea was to compare two groups of patients: those who had no osteoarthritis (OA) in one knee but who later developed osteoarthritis (group one) and those who did not develop OA at all. Everyone in the two groups was in the study because they had OA in one knee but not the other. It was the uninvolved knee that these researchers paid close attention to.

    X-ray evidence was used to determine who had osteoarthritis (OA) in the first place and that it was only present in one knee. X-rays were also used to diagnosis the new onset of OA in the knee that previously was healthy without signs of joint change typical of OA (e.g., joint space narrowing, cartilage defects, changes in bone size).

    Then they looked for differences between the two groups that might be considered risk factors for the development of OA. One of those variables was the presence of meniscal damage. MRIs were used to look for tears and helped in classifying the type, direction, and size of the tear(s). Size was measured in terms of length, width, and depth. They also measured how much the meniscus extruded (or protruded) out from inside the joint.

    They found that the larger and more complex the meniscal tear was the greater likelihood of osteoarthritic changes in that knee. Tears across the meniscus (rather than horizontal tears along the length of the cartilage) were a greater risk factor when the tear went through at least one-third of the meniscus. It was also the case that if more than half of the torn meniscus was observed outside the boundaries of the joint, it was considered “severe” and a risk for the development of OA.

    Of course, the next question was: what makes an untreated meniscal tear a risk factor for damage to the joint surface and resultant osteoarthritic changes of the knee joint? It turns out that two-thirds of the patients who had a meniscal tear and then developed OA had an injury of the posterior horn of the meniscus. As the name suggests, the posterior horn is the curved section of the meniscus along the very back of the knee.

    Having both a posterior horn tear and severe extrusion did NOT increase the risk of developing OA. However, extrusion seemed to be a risk factor for longer meniscal tears. These two combined together were seen more often in the patients who did develop osteoarthritis.

    The authors conclude by saying that once risk factors (such as meniscal tears) for osteoarthritis (OA) are identified, treatment that will yield the best results can be determined. Not all meniscal injuries result in OA, so their efforts to find the most significant characteristics of meniscal injuries are important.

    For now, it looks like complex tears, meniscus that extrude out of the joint, and injuries that are wider and/or longer than one-third of the meniscus were present in patients who developed X-ray evidence of osteoarthritis later.

    The Future of ACL Grafts: Is It Here Yet?

    Right now the “gold standard” for reconstructive surgery of the anterior cruciate ligament (ACL) is graft replacement of the ruptured tendon. The surgeon uses either a piece of the patient’s patellar tendon or hamstrings tendon. Tiny tunnels are drilled through the bone to secure and attach the graft tissue.

    But for as many advantages as there are to these graft options, there are just as many disadvantages. The disadvantages are the reason researchers continue to look for other treatment approaches that have fewer limitations and fewer adverse effects. Tissue engineering, the use of growth factors, bone morphogenetic protein (BMP), and other types of cells in ACL reconstructive surgery remain under investigation.

    This topic is of interest to both medical and veterinary surgeons as humans and animals experience ACL damage requiring surgery. In this review article from the School of Veterinary Medicine in Shiraz, Iran, veterinarians present an update on graft selection in ACL reconstruction and efforts to improve bone tunnel healing. They discuss past treatment choices, current strategies, and reflect upon future approaches.

    The authors provide a nice summary in table form of the advantages and disadvantages of three graft types used in ACL reconstruction (autograft, allograft, artificial or xenograft). After giving an in-depth discussion of each type, they briefly summarize the pros and cons of each one.

    For example, patellar tendon grafts are thicker and therefore stronger (biologically and mechanically) compared with hamstring tendon grafts. But the patellar tendon graft leaves a more unsightly and visible scar and they are slower to incorporate into the body and heal. Because the graft tissue is taken from the soft tissues that help extend (straighten) the knee, there can be a negative effect on the knee extensor mechanism.

    Patellar tendon grafts harvest easily so the time in surgery is less but the cost is higher compared with hamstring tendon grafts. Potential surgical and post-operative complications include patellar fracture, patellar tendinopathy, knee pain, and patellar crepitus (crunching or clicking of the patella as it moves up and down over the knee).

    Hamstring tendon grafts (when taken from the patient) have a higher rate of problems at the donor site. But rehabilitation is less intensive compared with patellar tendon grafts. On the plus side, there are no obvious scars at the donor site making them more pleasing cosmetically. Attaching the graft (called fixation) can be a challenge.

    Patients who have hamstring tendon grafts can lose some of the function of the hamstrings. The end-result may be less than a full return to all activities. Graft failure and rupture at the bone tunnel site occurs more often with hamstring tendon grafts. So does degenerative joint disease several years down the road.

    Knee joint laxity is reported more often with hamstring tendon grafts compared with patellar tendon grafts. This may be because there is more elasticity in the hamstring tendon compared with the stiffer patellar tendon.

    So — what is the future of ACL reconstruction? Can surgeons find a better way to deal with the limitations by improving the current surgical approaches? Can scientists find alternatives that improve the healing potential, shorten the time in rehabilitation, and yield better results with fewer problems and a lower failure rate?

    The answer to the first question is found in the details of this article. Many efforts are being made and reported by surgeons to find solutions by changing and improving surgical technique. The answer to the second question is: not yet. Xenografts (e.g., from calf skin or calf small intestine) are not readily available as yet. Efforts to develop an artificial ligament (also referred to as a ligament-augmentation device) have not been successful as yet. Such a system could help patients heal and rehab faster but may not be as strong or as resilient as natural tissue.

    Joint Infection After Knee Replacement: Why and What to Do About It.

    With more and more older adults getting knee joint replacements, the risk of deep joint infection becomes a concern. It is one complication that can put the entire knee (and new joint) at risk and is the number one reason for additional surgery. How often does it happen? Why does it happen? And what can be done about it? Those are the three questions raised and answered in this study.

    Researchers at the very large and very well-known Kaiser Permanente health care system in California conducted this study. They reviewed the medical records of the 56,216 patients who had a total knee replacement at any one of their hospitals. They collected information from the charts about the patients, the diagnosis, the surgeon, the surgery, and the hospital.

    The first question they asked (and answered) was: how often does this happen? Turns out that about 0.72 per cent of the total 56,216 patients developed the kind of deep joint infection being studied. And this rate was very close to what has been reported in other similar studies.

    After analyzing all the data, they were able to identify some specific patient and hospital risk factors. They also point out some protective factors that might be used in the future to reduce the number of deep joint infections. Some risk factors for postoperative infection are modifiable (something can be done to change the risk) while others are nonmodifiable (cannot be changed).

    For example, they found that patients of a Hispanic background actually have a lower risk of infection after joint replacement. On the other hand, men have a much higher risk compared with women. But obviously, there isn’t anything that can be done to change these two (nonmodifiable) risk factors except warn the patients of the possibilities.

    Age (young versus old) does not seem to make a difference but body mass index (BMI) and diabetes both increase the risk of deep infection following knee joint replacement. These are considered modifiable patient-related risk factors. There were also a few surgical-related risk factors such as longer operative time and the use of antibiotic-laden cement.

    Protective surgical factors include lower annual hospital volume (fewer patients seen each year) and having both knees replaced at the same time. Bilateral knee replacement is preferred by a smaller number of select patients who must be pre-approved for this procedure by their physician.

    In conclusion, this very large study including many different ages, races, and patient characteristics offered some insight into the problem of (and solutions to) deep joint infection after a knee replacement. Overweight patients who have diabetes and men should be advised that their risk of infection is increased by these factors.

    And surgeons should be advised to continue using antibiotics in the irrigation procedure to reduce the risk of infection. There is some doubt that cement used to implant the replacement parts that has antibiotics incorporated into it may not be helpful.

    New Y-Graft Technique for Dislocating Kneecap

    The patella or kneecap is a marvelous and complex structure. Held over the knee joint by soft tissue structures, it moves or “tracks” up and down with knee motion. Anatomists are still exploring and learning how the patellar tracking mechanism really works. Understanding normal patellar anatomy and kinematics (movement) will help surgeons repair and restore this part of the knee when injury leads to chronic, painful patellar dislocations.

    In fact, it is estimated that a second recurrent (repeated) patellar dislocations occur in almost half of all cases where a first or primary dislocation has occurred. There are many possible reasons for this scenario.

    Sometimes the torn medial patellofemoral ligament (MPFL) fails to heal. Or the MPFL heals in the wrong position (stretched or torn fibers are now too long). This soft tissue structure provides passive restraint (holds the patella in place) as the kneecap moves during the first 30 degrees of knee flexion.

    Other factors may be at work as well such as the resting position of the patella over the knee joint (pulled up too high or pushed down too low can cause problems). Weakness of the vastus medialis oblique (portion of the quadriceps muscle along the front inside of the thigh/knee) may be an important feature of patellar instability.

    Studies have now shown that this soft tissue structure blends with a portion of the medial patellofemoral ligament (MPFL). The two structures work together to keep the patella in the center of the knee as it starts tracking during knee flexion. To help restore the knee to as close to normal anatomy after recurrent dislocations, a new surgical technique has been developed.

    In this study, surgeons in China report on the results of this new approach they call the Y-graft technique. They compare the outcomes of the Y-graft with the more commonly used C-graft technique. They describe each method and provide drawings to assist surgeons in understanding the differences between these two surgical approaches.

    The basic difference is in the shape of the graft tissue and the fixation sequence. Fixation sequence refers to how and when the two ends of each graft are attached. For example, the C-graft procedure attaches both ends to the femur (lower leg bone) at the same time. Tension on the two ends of the graft is set at the same time.

    The Y-graft technique allows the surgeon to apply tension to the separate ends one at a time with the knee in zero degrees of flexion (i.e., straight) and then at 30 degrees of flexion. This separate graft tensioning helps mimic the more normal anatomy (alignment) and kinematics (movement). A special table summarizing the differences between these two fixation methods is also provided to help surgeons understand how the two techniques compare.

    Results comparing two patient groups with chronic, painful patellar dislocations (one group had the Y-graft, the second group had the C-graft) were measured using clinical tests and CT scans. Knee function, patellar stability, and patellar angles were the main outcome measures. With regular follow-up for two years, they found that the Y-graft did provide better knee function compared with the C-graft. And the Y-graft (double-bundle technique) restored normal patellar tracking much better than the C-graft (single-bundle technique).

    But the clinical results were not significantly better in the Y-graft group as might be expected. For example, patellar angles quickly returned to normal for both groups. Knee range-of-motion was also fully restored for all patients in both groups. No one in either group had any more patellar dislocations during the first two years of follow-up.

    Right now, there is no agreement or consensus on the best way to reconstruct a torn medial patellofemoral ligament (MPFL) in order to restore patellar stability. This study showed that the new Y-graft technique has the strength needed to hold the kneecap in place during movement requiring patellar tracking up and down over the knee. The Y-graft outperformed the more commonly used C-graft technique. Further follow-up is needed now because recurrent patellar dislocations tend to develop more as time goes by.

    Five “Plusses” for New Superficial Quadriceps Graft

    Around the world, surgeons are working to find better ways to reconstruct the medial patellofemoral ligament (MPFL). We reported on a previous study from China on this topic. Now here is another from India.

    The MPFL is the stabilizing ligament that helps keep the patella (knee cap) tracking up and down over the knee. When the patella is dislocated, this ligament is almost always ruptured. And once a ligament is torn, it does not repair or heal itself. Chronic, recurrent patellar dislocation with MPFL rupture is referred to as medial patellofemoral insufficiency.

    In order to regain patellar stability and prevent repeated dislocations (ligament insufficiency leading to patellar instability), (surgical) reconstruction is needed. There are many different ways to reconstruct the damaged ligament. Most techniques involve a tendon graft to replace the ligament. Attaching the graft in place (called fixation) creates problems of its own. That’s one reason why surgeons are looking for better ways to accomplish the reconstruction procedure.

    In this study, one surgeon from the Saumya Orthocare: Centre for Advanced Surgeries of the Knee Joint in India investigated the use of the superficial quad technique. A superficial slip of the quadriceps tendon is used as the graft. The quadriceps muscle is the large four-part muscle along the front of the thigh. The quadriceps tendon attaches to and around the patella. There are five advantages or “plusses” to this new technique.

    First, the graft is a better anatomic match to the original medial patellofemoral ligament (MPFL) in terms of width, breadth, and length. The natural or native MPFL is thin, broad, and sheet-like; so is the quadriceps slip used in this procedure. Two, the superficial quadriceps tendon graft is not as stiff as the commonly used hamstring tendon graft. A strong, stiff graft puts more load on the patellofemoral joint and can cause patellar fracture later.

    Three, the superficial quadriceps graft does not have to be held in place with screws or wires. This makes it possible to attach the graft to the medial border of the patella where the MPFL is located normally. The result is a more accurate re-creation of patella biomechanics and elimination of complications from patellar fixation. This is helpful because most common problems that develop after MPFL reconstruction can be traced back to either the type of graft material or the way in which the graft is held (i.e., fixation technique used) in place.

    Four, the graft can be harvested arthroscopically with a very small incision. And five, at least in the short-run (first three years), the results are equal to outcomes when compared with using the hamstring tendon.

    For those surgeons who are interested in taking a closer look at the superficial quadriceps tendon graft technique to reconstruct a ruptured medial patellofemoral ligament, this article includes a description and photographic display of the 10 steps for the surgical procedure.

    The author begins with arthroscopic examination to assess all injuries and damage inside and around the knee joint. Graft harvest, preparation of the graft, and attachment of the graft are part of steps two through eight. The final steps involve getting the most optimal graft length and then repairing any other soft tissue injuries (e.g., medial retinaculum).

    In the follow-up of these 32 patients, no one had recurrent patellar dislocations or other patellar complications. One-fourth of the group had problems bending the knee fully and went to physical therapy to resolve the issue. The author suggests that future improvements of the superficial quadriceps procedure (e.g., better fixation points at the femur, elimination of scarring, better arthroscopic techniques) may help prevent this complication and further improve results.

    Platelet-Rich Plasma Outperforms Shock Wave Therapy for Jumper’s Knee

    Running and jumping over and over often leads to a condition in athletes known as patellar tendinosis or jumper’s knee. Pain along the front of the knee during the activity that goes away with rest is a cardinal symptom of this condition. Dancers, gymnasts, and basketball, soccer, and volleyball players are affected most often.

    What can be done about his problem? Jumper’s knee goes away when the muscles along the front of the knee (extensor mechanism) that pull across the patella (kneecap) stop pulling. It is a self-limiting, self-resolving condition. Therefore, the first recommended treatment is always to stop overloading the extensor mechanism. Rest, anti-inflammatory medications, and specific exercises under the supervision of a physical therapist are advised.

    But many athletes work through the pain until conservative (nonoperative care as described above) is no longer successful in reducing pain. At that point other treatment options are considered. In this study, sports medicine experts compared two additional treatment approaches for chronic tendinopathy of the extensor mechanism: 1) platelet-rich plasma (blood injection therapy) and 2) extracorporeal shock wave therapy (ESWT).

    Platelet-rich plasma (PRP) refers to a sample of serum (blood) plasma that has four (up to 10) times more than the normal amount of platelets and growth factors. This treatment enhances the body’s natural ability to heal itself and is used to improve healing and shorten recovery time from acute and chronic soft tissue injuries. The group of athletes in this study who received PRP were given two injections over a two week period.

    Extracorporeal shock wave therapy (ESWT) is a way to generate sound waves outside the body that can be focused at a specific site within the body (in this case, the knee). This treatment technique is also referred to as pressure or sound wave therapy. It is a noninvasive, outpatient procedure.

    Pressure waves travel through fluid and soft tissue to sites where there is a change in tissue density. A common interface is where the soft tissues meet bone. A special device delivers shockwaves to the target point where treatment is needed. The shockwaves break down scar tissue that has built up. The body’s repair mechanisms are stimulated to promote healing. New blood vessels develop in the injured area to help jump start the healing process. Three sessions of ESWT were delivered to the second group in this study in 48- to 72-hour intervals.

    In order to measure and compare results between the two groups, they used three tools: 1) the Victorian Institute Sports Assessment-Patella questionnaire, 2) the pain visual analog scale, and 3) a modified version of the Blazina scale. The athletes completed each questionnaire before treatment and again after treatment at two, six, and 12 months post-treatment. Information gained from these surveys included: severity of pain, level of function, and ability to participate in sport(s).

    In comparing the two groups responses to treatment, they found everyone in both groups had significant improvements throughout the follow-up time period. At the end of two months, there was no real difference between the two groups. But later (at the six-month and one-year recheck), the platelet-rich plasma (PRP) injection group pulled ahead with significantly better improvement. Significantly more athletes in the PRP group (compared with the shock therapy group) were also able to return to full sports participation (at a level equal to before their injury).

    This may be the first randomized, controlled trial comparing treatment results between these two approaches in athletes with jumper’s knee. Both treatments focus on the failed healing of the overused tendon by promoting cell growth, release of growth factors, and improving tissue remodeling. As this study showed, both are effective in the short term but platelet-rich plasma may have better mid-term results. Further study is needed to assess long-term results.

    One PRP Injection May Be All That is Needed for Painful Knee Arthritis

    Platelet-rich plasma (PRP), also known as blood injection therapy, continues to be investigated by researchers. They are looking for a way to control painful symptoms from knee osteoarthritis. Efforts to regenerate lost joint cartilage using this type of treatment may also help slow down the disease process.

    Scientists still aren’t quite sure how these therapeutic proteins aid in cartilage repair. The basic idea is to remove platelets from the patient’s own blood and inject it into the joint. The blood plasma is prepared in such a way as to include three to four times more than the normal amount of platelets.

    Platelets have growth factors that may speed up the body’s natural healing process. This treatment may shorten recovery time from acute soft tissue injuries. In the case of chronic joint degeneration, it may stimulate a healing process in the joint cartilage (called chondrogenesis).

    But as you will see from this study, the benefits reported by patients (decreased pain and stiffness and increased motion and function) came after only slightly more than two weeks. And that might be too quick to really be caused by true joint regeneration. The authors suggest perhaps the platelet-rich plasma improves overall joint environment making it possible for the joint to “feel better” even when cartilage tissue isn’t changed directly.

    We may not know for a while just how PRP therapy works. But studies like this one will help determine the best way to administer the treatment for optimal results. There were a total of 78 patients (156 knees) who received either one PRP injection, two PRP injections (spaced three weeks apart), or a placebo (injection containing just a saline solution).

    Results were compared among the three groups using patient report of pain levels, stiffness, physical fitness, and complications. They used the Western Ontario and McMaster Universities Arthritis Index (WOMAC) questionnaire. This survey was given to the patients both before and after treatment to assess changes in these measures. They also asked about patient satisfaction with treatment.

    They found that patients started noticing a difference in their symptoms anywhere between 13 and 19 days after the first injection. There was a significant improvement in patients who actually received the platelet-rich plasma compared with the placebo injection. But the benefits reported weren’t any better or greater with two injections compared with one.

    There were some adverse effects of treatment (e.g., dizziness, headache, nausea, increased heart rate) in the injection groups only. Patients who received the most number of platelets were more likely to experience these complications. So for example, 22 per cent of the single-injection group reported problems but 44 per cent of the group who received two injections experienced side effects. In other words, twice as many people in the two-injection group had complications compared with the single injection group. These effects were considered mild and only lasted a short time.

    Everyone was followed for up to six months to see the long-term effects of platelet-rich plasma (PRP) injection therapy. Two-thirds of the two groups who received PRP injections were satisfied with the results. That compared with almost 90 per cent of the placebo group who were NOT happy with the results. Patients with milder osteoarthritis seemed to get the most benefit from the PRP treatment.

    It was apparent from analysis of the data collected between the six weeks period to six months that the positive results started to decline over time. The trend was for a gradual worsening of symptoms as time went by. But the pain, stiffness, and function were still much better than before the injection therapy.

    The authors concluded that platelet-rich plasma (PRP) injections may not be the “wonder drug” some say they are but they do provide significant symptom relief. A single injection may be all that is needed every six months to aid in managing the pain and stiffness.

    This type of “staged” treatment approach may provide enough improvement in patient function to make it worth the expense. Until more is understood about how PRP works, it may be enough to use the treatment as a temporary management tool against the early effects of osteoarthritis.

    Fear-Based Problems After Total Knee Replacement

    Before reaching the point of needing, wanting, and accepting a total knee replacement for joint arthritis, many people become fearful of movement (kinesiophobic). Their level of pain causes them to start avoiding certain movements and activities at home and work. This pattern of behavior is called fear-avoidance.

    Long periods of time in the fear-avoidance mode of thinking and acting can eventually lead to loss of function and disability. Without movement, knee osteoarthritis is known to get worse, causing more pain. Before you know it, the person becomes kinesiophobic (afraid to move), sacrificing everyday activities and tasks. A viscious cycle of pain-fear-disability-pain develops that can be hard to break.

    In fact, this pattern of pain-related fear does not automatically go away after the joint is replaced. That’s why this study from Italy was done by a group of physicians and physical therapists. They wanted to compare two different approaches to rehabilitation based on measures of fear-avoidance, pain intensity, and quality of life. The idea is to find the best way to restore full motion and function without the element of fear preventing recovery and return to all activities.

    The 110 patients in the study were divided into two groups. The experimental group was given a special exercise program and a book with information about how to manage (and overcome) kinesiophobia. The exercises were to be done twice a week for six months. Everyone in this group was instructed in functional exercises before leaving the hospital.

    Functional exercises refers to a type of program designed to do more than just regain 90-degrees of knee flexion or lift the leg off the bed ten times. Functional exercise-based rehabilitation programs are geared toward improving motion and strength while preventing blood clot formation and while restoring specific activities. Walking; climbing stairs; and making sudden starts, stops, and turns are just a few examples of the skills functional exercises work to restore.

    The book the experimental group received was designed to help them understand their own unwillingness to go out shopping, go for a walk, return to work, or ride a bike. By practicing physical activities and movements at home, the patients in this group were encouraged to perform all these things without fear. The goal was to increase activities previously considered “dangerous” (i.e., before surgery). This was to be done slowly but steadily over the six months’ period of time after surgery.

    The control group was just advised to stay active. They were told to gradually increase their activity level until they returned to normal (defined as their “usual” activities). Patients were randomly assigned to one of these two groups (experimental or control).

    After six months, it was clear that the experimental group had much better results compared with the control group. Disability level was much lower and quality of life was much higher in the experimental group. Fear-avoidance behaviors were also less common among the exercise group. Based on their findings in this study, the authors proposed the following:

  • Before knee replacement, all patients should be screened to identify those individuals who have pain-related fear of movement.
  • Anyone at risk for problems after total knee replacement because of fear-avoidance behaviors should receive education about kinesiophobia and a special rehab program.
  • Specific “graded” (in other words, slowly progressed) functional exercises should be prescribed and supervised until knee motion, daily activities, and physical function can be done with confidence and without fear.
  • Such a program can be taught to the patient while still in the hospital for the surgery. A follow-up home program may be enough to take care of the problem. Future studies are needed to know for sure exactly what type of rehab program (and for how long the program) should be provided.

    The authors concluded that it is possible to pre-identify (before surgery) patients whose recovery from a total knee replacement may be compromised by fear-avoidance thinking and behaviors. Education and exercise can help correct these behaviors and aid patients in overcoming barriers to full recovery. Addressing and treating kinesiophobia in this way puts the burden of responsibility for recovery from mistaken beliefs and thoughts squarely on the patient’s shoulders.

  • Knee Pain and Joint Motion Improved for Arthritis Using Aquatic Therapy

    Many studies show the benefit of exercise for people with knee osteoarthritis. But pounding the pavement (walking) can increase pain. Aquatic therapy in a pool of warm, supportive water is one way to get the needed exercise without the added stress.

    In this study from the University of Florida, the effects of walking on a treadmill underwater were compared with walking on a land treadmill. It was a small study with 14 adults in ages ranging from 43 to 64. All participants had been formally diagnosed with knee osteoarthritis (OA). A few had OA of the hip or ankle as well.

    Everyone was treated with a 20-minute session on a treadmill at zero incline (flat). The 20-minute period was broken into four stages each lasting five minutes. Pace or speed of walking increased slightly with each stage. By the last five minute segment, the patients were walking at a moderate-to-somewhat hard level of perceived exertion.

    Three sessions were completed in one week on the aquatic treadmill with water temperature holding steady at 86 degrees Fahrenheit. Then there was a one-week rest period and the same protocol was used on a land treadmill. Some patients did the land treadmill the first week while others were assigned to the aquatic treadmill first. Who did what first was randomly assigned using a computer program.

    It should be noted that walking on a treadmill in water is not the same as walking in water without a treadmill. When using a treadmill in a pool, only the lower half of the body is underwater (which makes it easier to walk). Walking without the benefit of a treadmill places the feet on the bottom of the pool so more body is submerged making it more difficult to move.

    The more body that is underwater, the greater the “fluid drag,” which slows a person down. Studies comparing energy required to walk on an aquatic treadmill versus a land treadmill show similar energy requirements. In other words, it is not more difficult or exhausting to walk on a treadmill underwater compared with a land treadmill.

    Aquatic treadmill walking has also been shown to decrease the impact on the knee. The buoyancy of the water reduces the force from the ground starting at the foot and traveling up to the knee (called the ground reaction force). It was hypothesized that decreasing the joint load by using an aquatic treadmill would reduce pain and improve exercise quantity and quality. Let’s see if that is what happened in this study.

    Results were measured within 24 hours of completing the three sessions (on either treadmill). They used two main outcomes: change in pain level and joint kinematics. Kinematics refers to how the joints move (speed or velocity, joint angle, step length, step rate).

    Changes in pain and kinematics can affect a person’s gait (walking) pattern. Joint kinematic measurements were taken while the patients walked on land in a biomechanics lab. The researchers measured angular velocity for knee extension during stance (weight on that leg) and knee extension and internal rotation during swing (leg moving forward).

    The angular velocities measured did improve more after aquatic therapy. Angular velocity gain for left knee extension during stance improved significantly (38 per cent) after aquatic walking. Gain for knee internal rotation was 65 per cent and 20 per cent improved for knee extension during leg swing. Pain was significantly greater (100 per cent more) after land exercise. The number of steps taken and the length of steps did not change with either form of exercise.

    The authors point out that these kinds of changes in angular velocity indicate that the pattern of movement of the arthritic knee is improved during walking. That is important for restoring normal gait (walking), improving balance, and preventing falls. The actual mechanism for increasing angular velocity and joint kinematics remains unknown. It is thought that the combination of increase in fluid resistance, warmth and pressure of the water, and unloading of the joints work together to create these beneficial effects.

    With only three sessions each (aquatic and land) on the treadmill, these outcomes are considered short-term. But evidently there was enough effect on the neuromuscular system to create these changes. Future research will be needed to see if the changes last (and for how long) and whether a longer period of time with more sessions would enhance the benefits even more.

    The authors concluded that aquatic therapy may be a good alternative to walking on land for patients with painful and limiting knee osteoarthritis. This treatment approach can help patients experience pain relief and improve walking ability.

    Using MRIs to Predict Recovery From Hamstring Injury

    Many athletes involved in running sports (e.g., rugby, soccer, football, basketball) with fast starts and sudden stops injure their hamstring muscle. Of course, the first thing they want to know is how long will it take to recover and get back in the game? The answer is not always so easy to provide. It seems recovery time varies significantly from player to play. Not only that, but second injuries to the same muscle can occur, especially if the player goes back to the game too soon.

    In this study, researchers from Australia evaluate the use of MRIs to predict recovery time from hamstring injuries. They particularly focus on hamstring injuries that involve disruption of the central tendon.

    The hamstring muscle is the large muscle along the back of the thigh. It is made up of three muscles and their tendons: the biceps femoris, semimembranosus, and semitendinosus. The central tendon runs down the center of the muscle for the full length of the hamstrings.

    The reason this tendinous portion of the muscle is important is because injury to this area often means a longer, slower recovery. Using MRIs to assess hamstring muscle injury might aid the surgeon in making predictions about expected length of time for recovery. Returning to sports activities too soon is linked with an increased risk of reinjury. Avoiding recurrent damage to the hamstring muscle is an important goal.

    To find out if MRIs can be used in this way, the records of 62 elite athletes with hamstring injuries were reviewed. Each one had MRIs taken. The investigators could compare the results and the recovery time for hamstring injuries in players with central tendon disruption against players with hamstring muscle injuries.

    MRIs showed that central tendon disruption only occurred in injuries involving the biceps femoris. Almost half (45 per cent) of the hamstring muscle injuries of the biceps femoris included central tendon disruption. Comparing recovery times, it was clear that recovery took much longer for injuries involving the central tendon.

    In general for all the players combined, recovery time varied from as short as two weeks up to six weeks. Comparing injuries to the three hamstring muscles (semimembranosus, semitendinosus, and biceps femoris), the recovery time was the same. In other words, there was no significant difference in recovery time for the three hamstring muscles.

    Recovery time for central tendon injuries of the biceps femoris was much longer (72 to 91 days). Tendons have less blood supply than muscle fibers so this delay in recovery when the central tendon is injured makes sense. The shorter time (72 days) was for players with this type of injury who were treated conservatively (without surgery). The longer recovery time (91 days) was associated with players who had surgery to repair the damage.

    The authors conclude that hamstring injuries involving the central tendon do take much longer to heal. And MRIs do have prognostic value. They can help identify this type of injury early, which can help surgeons and players plan treatment and return-to-sports accordingly. Central tendon disruption can be seen on MRIs and is considered a new prognostic sign. This is the first study to report on the value of MRIs in finding central tendon disruption.

    The next step in research is to examine whether different treatment (surgery versus conservative care) and different rehab programs yield better results for these two distinct injuries (muscle versus tendon). Risk of recurrence and recurrence rates should also be studied for hamstring muscle versus hamstring (central) tendon. Some studies have already been done looking at the severity of hamstring injury and time to recovery. The authors of this study point out the need to also compare severity of muscle versus tendon on recovery rates.

    High Failure Rate with MACT for Young Knees

    Orthopedic surgeons from Italy report a high failure rate using matrix-assisted autologous chondrocyte transplantation (MACT) for young patients. Forty-four patients between the ages of 20 and 58 years of age with osteoarthritis from damage to the knee joint cartilage were included in the study.

    Each one had a hole or defect in the joint cartilage that went all the way down to the bone. Symptoms of knee pain, swelling, locking and giving way and the formation of degenerative arthritis brought them in for treatment. Prior treatment failed and each one in the group was either too young for a joint replacement or did not want a prosthetic implant.

    They were all treated with the MACT procedure with three goals in mind: 1) provide pain relief, 2) stop or at least slow the progression of osteoarthritis, and 3) eliminate the need for a joint replacement.

    MACT is a three-step process: first normal, healthy cartilage cells are taken from a non weight-bearing area of the patient’s own knee. Then these cells are transferred to a lab where they are placed on a special scaffold. More cells are grown (forming a matrix). The last step is to implant the bioengineered tissue into the defect.

    After the procedure, everyone had at 12 or more weeks of rehab. Follow-up was at least seven years with some patients being in the study for up to 10 years. These long-term results were disappointing as half the group said they were no better off than before the surgery. And almost 40 per cent said they wouldn’t do it again if they had it to do over.

    The surgeons suggest that one of the factors that affected the results was previous treatment. Patients who had removal of part or all of the meniscus (meniscectomy) had the poorest clinical outcomes. It didn’t seem to matter whether the amount of osteoarthritis already present was mild, moderate, or severe. The reported results were the same for all levels of degeneration.

    The surgeons concluded from this study that the use of a scaffold-based or matrix of bioengineered tissue to aid cartilage regeneration may not be advised in young adults. In particular clinical results were unfavorable in young adults with knee osteoarthritis who had prior knee surgery. In other words, matrix-assisted autologous chondrocyte transplantation (MATC) for knee osteoarthritis from this type of damage to the cartilage may not be the best salvage approach.

    More research is needed to discover why this treatment did not work. It is possible the joint being damaged by degenerative arthritis just doesn’t have the right ingredients (environment) to aid in a healing response. MATC might work best for those individuals with cartilage lesions who have NOT had a previous meniscectomy. Further study is also needed to explore the limits of scaffold-based treatment for this type of problem in young adults.

    One-Fourth of All Meniscal Repairs Fail

    There is a 24 per cent failure rate for meniscal repairs five years after the operation. This is true whether you have a medial or lateral repair. The rates are the same if you have an intact or damaged anterior cruciate ligament (ACL). And the five-year outcomes are the same if the damaged ACL is repaired or reconstructed.

    These are the results of a systematic literature review and meta-analysis conducted by researchers at the Washington University School of Medicine in St. Louis. The study was done by the Sports Division of their Department of Orthopaedic Surgery. By pooling the data from 13 high-quality studies, the authors were able to provide a five-year perspective for the modern arthroscopic repairs used most often.

    Although they hypothesized and hoped that short-term results (after two years) that were previously reported would be maintained long-term, that was not the actual fact. Instead, nearly one-fourth of all patients continued to experience mechanical symptoms (knee pain, clicking, locking) or recurrent tears requiring additional surgery.

    This large failure rate was consistent for open surgery as well as arthroscopic procedures (using all types of surgical repair techniques). The rate was similar no matter what type of rehab program was used (nonweight-bearing for four weeks, early weight-bearing, early range, of motion, or immobilization with cast, splint, or brace).

    The authors did not offer any suggestions or reasons why the failure rate following meniscal repairs is so high. This is one of the first studies to take a look at medium-term outcomes with the more modern arthroscopic approaches to meniscal repairs. The 24 per cent failure rate was consistent across all studies no matter what variables were analyzed. Most of the failures developed after two years post-operatively. Data on results past five years is not available yet.

    The meniscus is a very important structure in providing the knee with normal function. It also helps prevent damage to the joint surface and degenerative arthritis. Despite what are considered improved surgical techniques, results are not improved. Further studies are needed to resolve this issue.

    Patellar Resurfacing as Part of a Knee Replacement: Yes or No?

    Most people don’t realize that a total knee replacement can involve three component parts. There is the femoral side of the joint (the bottom portion of the femur or upper thigh bone). Then there is the tibial side of the joint (the upper part of the tibia or lower leg bone). Those two components make up the main knee joint as we think about it.

    But there is a third piece and that’s the patella (knee cap). The patellofemoral joint (patella sliding and gliding up and down over the front of the knee) is an important part of the entire knee complex.

    The question is: should the patella be resurfaced during the total knee replacement procedure? Resurfacing means the back of the patella is lined with a polyethylene (plastic) dome to allow it to move freely and smoothly once again. There is considerable debate among orthopedic surgeons about the benefits and disadvantages of patellar resurfacing.

    To help sort out the question of whether or not patellar resurfacing is helpful, a meta-analysis was conducted. Researchers reviewed randomized controlled studies reported from as early as 1995 to the present time. A total of 3,465 knee replacements were included, divided evenly into two groups: those who had patellar resurfacing as part of their knee replacement and those who did not.

    The three main measures of patient outcomes included: pain, function, and patient satisfaction. Other secondary results compared were rate of reoperation, complications, operative time, and X-ray findings.

    There isn’t much to report because except for rate of reoperation, there were no significant differences between the two groups. Pain levels after surgery, patient reported knee motion and function were the same, and 89 to 90 per cent of both groups were happy with the results. The rate of post-operative infection was low (between one and two per cent) for both groups. And the amount of time in surgery wasn’t different enough to be considered significant from a statistical analysis perspective.

    The only statistically significant difference between the two groups was a much higher rate of reoperation in the nonresurfaced group. Most of these second surgeries were done because of knee pain. Some of the patellar resurfacing group had to have additional surgery because of complications but the rate was much lower in the resurfacing group compared with the nonresurfacing patients.

    In theory, resurfacing should take more time and increase the risk of infection. But as this study showed, in practice this just isn’t the case. Most of the results from this meta-analysis don’t favor routine resurfacing as part of a total knee replacement. There is not clear proof that continued knee pain in patients who did not have patellar resurfacing was really due to lack of patellar resurfacing.

    No firm conclusions could be made from this meta-analysis. The authors note there are just too many other variables to consider such as changes in the design of knee implants over the years, changes in surgical technique over the same time period, and differences in surgical techniques used. The fact that patient satisfaction was equal between the two groups is significant.

    In the end, the decision to resurface (or not resurface) the patella as part of the knee replacement must be made together by the patient and surgeon. Surgeons must keep up with the results of studies like this one in order to consider all the current evidence available when advising and counseling patients individually.

    Reducing ACL Injuries in Women

    It is a well-known fact that women athletes are at greater risk for knee injuries compared with men. In particular, anterior cruciate ligament (ACL) injuries seem to plague female athletes much more often than men. In this article, orthopedic surgeons from the Department of Orthopaedics and Rehabilitation at Yale University review the risk factors and biomechanical differences between men and women. They also provide a treatment protocol for successful prevention of this problem.

    There are two types of risk factors that contribute to the sex differences in rates of ACL injuries between men and women. The first is intrinsic, meaning things inside the body that affect the ACL. Intrinsic risk factors include anatomic and biomechanic variables. For ACL injuries, research has shown that the number of degrees of the Q-angle, the geometry of the intercondylar notch, the size of the ACL, and the slope of the tibia are contributing factors.

    Hormone differences between men and women and genetic predisposition may be two additional risk factors. But data collected from studies so far has been insufficient to prove or disprove the role of either one in ACL injuries.

    Extrinsic risk factors remain under investigation, too. One thing we know that does NOT seem to bear any influence on ACL injuries is the lack of playing experience among women. The rate of ACL injuries among women hasn’t changed in the last 15 years. The number of females participating in sports HAS increased and along with that increase has come more injuries (not less as you might expect with increased experience).

    Other extrinsic factors under consideration include shoe-to-playing surface interaction (increased friction) and shoe construction. Shoes with larger cleats and more cleats seem to increase torsional force on the knee (transferred up to the knee from the foot-to-surface effect). There is even evidence that turf surface and climate (dryer climate) can increase the shoe-playing torsional factor.

    What can be done to help prevent ACL injuries among female athletes? Physical therapists have identified landing position as a key area to focus on. When female athletes jump and land with both feet in control, both hips and knees deeply bent and facing straight ahead, and equal weight on both feet, there are fewer injuries.

    But if even one leg is out of balance or the landing is compromised in any way, then the risk of ACL injury increases dramatically. The two different positions are referred to as the position of safety and the position of no return. Teaching women how to stay in the safety position (and having them practice this position daily) has proven to be successful in preventing ACL injuries.

    This type of neuromuscular and proprioceptive training under the guidance of a physical therapist significantly decreases the incidence of ACL injuries in soccer and basketball players. Studies show up to an 88 per cent reduction of ACL injuries in the first year the prevention program was started.

    Additionally, it has been determined that for the best results, the prevention program must be done three times a week for 10 minutes over a period of at least two months. The neuromuscular and proprioceptive program of exercises should be accompanied by other exercises as well (e.g., agility drills, core training, plyometrics). And a maintenance program is advised to avoid the effects of deconditioning.

    The authors do mention the role of surgery (type of surgery, potential complications of surgery, and expected outcomes with surgery). But the main focus of their review was on identifying and preventing intrinsic and extrinsic risk factors with conservative (nonoperative) care.

    Types and Treatment of Infection After Knee Replacement

    As the authors of this article point out, infection after total knee replacement is the most “dreaded and difficult” of all complications. Joint infection can be difficult to treat, requiring removal of the implant and revision surgery to put in a second implant.

    According to their review of the literature, this problem is increasing not decreasing. Up to two per cent of all senior adults who have this surgery will end up with an infection that requires further treatment. The rate of failure due to infection is double that for revisions so having a second surgery doesn’t necessarily mean the end of the problem. In fact, almost 17 per cent of revision total knee arthroplasty (TKA) procedures end in another surgery.

    If this problem isn’t turned around in the next 10 years, it is estimated that two-thirds of all revision procedures will be needed because of post-operative infection. Prevention is the key but today’s bacteria are stronger and more resistant to antibiotics than ever before. Prevention strategies are not the focus of this article. Instead, surgeons treating patients with this problem will appreciate the review of treatment options provided.

    The authors start out by classifying knee infections that occur after the primary (first) total knee replacement as one of four types: 1) infection present at the time of the primary total knee arthroplasty, 2) infection develops within the first 30-days after surgery, 3) infection goes into the blood but symptoms only last four-weeks, and 4) a chronic infection lasting more than 30-days.

    Treatment is based on the infection type and condition of the patient. Treatment choices include: antibiotics, irrigation and debridement, removal and replacement of the implant, arthrodesis (fusion), and (worse case scenario): amputation. Who gets what treatment? That’s the question these authors try to answer.

    First, they suggest that antibiotics alone (called antibiotic suppression) is very ineffective (20 per cent success rate) and only used for a small number of patients. These are folks who are too sick for surgery, who have a stable implant (not loose), and a bacteria that is considered “low virulence” (in other words, not terribly strong or destructive).

    The preferred treatment is actually more of a combined management approach. Open incision with irrigation and debridement works best for acute infections. But the surgeon must take into consideration several factors when using just this approach. For example, patient health, type of bacteria present, length of time since the primary surgery, and other patient risk factors must be reviewed and assessed before using this treatment option.

    More often, it is necessary to remove the infected implant, clean out the joint, and replace some of the component parts of the implant. The replacement procedure is referred to as an exchange arthroplasty. The exchange arthroplasty can be a one-step or two-step process (also known as one-stage or two-stage exchange arthroplasty).

    As the names suggest, in a one-stage procedure, everything is done in one surgery. In a two-stage exchange, the implant is removed but not replaced just yet. Instead a spacer that contains high-dose antibiotics is put in place instead.

    Once the infection is under control, then the spacer is removed and the replacement implant installed. It is important to make sure the areas down into the bones (both the femur — the thigh bone and the tibia — the lower leg bone) are free of infection before putting the replacement implant in. Using long, thin antibiotic dowels down into the canals along with the spacer helps solve this problem.

    When to reimplant the replacement parts is a challenge, too. Usually the antibiotics are used for at least six weeks with another four to six weeks time period off antibiotics before reimplantation can take place. Once the lab tests show the infection is cleared up, then the exchange can take place.

    The more extreme options of joint fusion or even amputation are only considered when all other treatment methods have failed. Amputation may be necessary when the infection cannot be stopped and the patient is either in terrible pain or their life is threatened by the infection spreading throughout the body. In all cases, every effort is made to save the leg, save the joint, save the implant. Fusion and/or amputation are only considered when all else has failed.

    In conclusion, with an expected rise in the number of older adults having a total knee replacement comes an expected increase in the number of cases of infection requiring follow-up treatment. The most common post-operative problems and complications encountered by patient and surgeon include infection, failure of the wound to heal, and loosening of the implant. The focus of this article is the management of acute and chronic cases of infection.

    Devastating Problem After Joint Replacement: Infection

    As a natural consequence of rising numbers of total hip and total knee joint replacements has been the increase in number of postoperative infections. This complication can have devastating results. It is a complex and challenging problem to solve for a number of reasons.

    First of all, general health and nutrition are very, very important in preventing infections or in the case of infections that do develop, in getting better. A healthy adult who is not overweight and does not have other problems has a better chance of recovery with less invasive treatment.

    Second, older adults are living longer with more comorbidities. Comorbidities refer to other diseases and illnesses present at the time of the joint replacement surgery. For example, high blood pressure, heart disease, obesity, diabetes, cancer, thyroid problems, gout, and arthritis are just a few of the more common problems seniors have — and most patients facing joint replacement have many health conditions referred to as multiple comorbidities.

    Third, it’s no secret that bacteria have become “superbugs” now. This means they are able to resist antibiotics previously used to kill them. They actually change their own structure and genetic code to shield themselves from the effects of antibiotics.

    And finally, infections that develop later or that are not treated early can become chronic. These types of infections are even more difficult to stop. Even with treatment to clean out the joint, remove, and replace the implant, these bacteria linger and can resurface when the second surgery is done. Bacteria that enter the blood stream can also travel throughout the body, sometimes even causing death from a condition known as septicemia.

    The fact is, infection after joint replacement is possible, affects up to two per cent of patients receiving their first implant, and costs four times the price of the replacement surgery. Surgeons are working hard to gather data and information that might help first with infection prevention and second with treatment.

    Forty years of research has shown that cleaning the joint (a procedure called irrigation and debridement) isn’t always enough. Current clinical guidelines based on evidence gathered over time recommend irrigation and debridement alone (preserving the original implant) only for certain patients.

    These select individuals 1) are in good health with good nutrition and good immune system function, 2) do NOT have the type of bacteria that are antibiotic resistant, 3) DO have an acute infection (early on after surgery) that is diagnosed quickly, and 4) are able to follow their physician’s advice about taking antibiotic therapy as directed.

    Research is ongoing trying to sort out the best approach to the problem of infection after joint replacement. Best antibiotic to use, length of time to use it, and method of delivery remain under investigation. Some surgeons are trying direct infusion of antibiotics into the joint for six weeks. This treatment approach is called intraarticular infusion. Others are trying repeated irrigation and debridement procedures either alone or in combination with removal and replacement of the infected implant parts.

    In summary, surgeons are reminded that irrigation and debridement to treat implant infection following either total hip or total knee replacements is not advised. Only those patients who meet the criteria just described should be selected for this more conservative care. There is plenty of evidence that irrigation and debridement alone will result in poor results and a poor prognosis with a high rate of implant failure.

    Improving Rehabilitation After ACL Reconstruction

    More than any other sports injury, rupture of the anterior cruciate ligament (ACL) in the knee has received a great deal of attention. Athletes can sustain this type of injury and still return to full sports participation. There is a concerted effort among researchers to find the best rehabilitation protocol for the fastest and safest return-to-sports.

    There are many different ways to approach the rehabilitation of ACL injuries. Sometimes it is possible to complete a conservative plan of exercise without surgery. This approach is most likely for the less active individual or the patient who did not completely rupture the ligament.

    Most of the time, active participants in sports and especially those players with a complete ACL rupture require surgery to reconstruct the ligament. Graft tissue taken from the patellar or hamstring tendons is used to replace the destroyed ligament. Rehab is always necessary after surgery. The goals are to regain motion, strength, and balance. Athletes have the additional goal of eventually returning to full level of sports play.

    In some places, early, aggressive rehab is started right away during the recovery process. This is referred to as accelerated rehabilitation. In other practices, bracing is used following surgery. Results or outcomes for both of these treatment interventions are reviewed and summarized in this article. The authors systematically review articles related to ACL rehab and published between 2006 and 2010.

    Evidence for other types of treatment currently used in ACL rehabilitation are also reviewed by these authors. For example, level one and level two evidence is presented regarding home-based rehab, vibration training, and proprioception and neuromuscular training.

    Here’s what you don’t need:

  • Bracing (any kind of bracing for any period of tiem) after ACL reconstruction isn’t needed. It doesn’t give the patient any advantage over those patients who don’t use braces. It’s simply an added, unnecessary cost.
  • Continuous passive motion (automatically moving the knee in a device made for that purpose) doesn’t result in more joint motion or improved proprioception (joint sens of position) for the patient. It is another added cost that can be done away with.
  • Mega-doses of vitamin C have not yet been shown to increase muscle fiber size or strength; there may be other added benefits to taking this supplement but more study is needed before a recommendation can be made.

    The jury is still out on:

  • The use of hyaluronic acid injections into the knee jointmay have some benefit but further cost-benefit analysis is needed.
  • Neuromuscular exercises won’t hurt after ACL reconstruction but they might not help much. At this time, this rehab tool should be in addition to traditional strengthening and range of motion exercises (not in place of).
  • Vibration therapy to help restore the joint’s sense of position (proprioception) and therefore improve knee joint stability might be helpful. But more study and high-level evidence is needed before specific recommendations can be made.

    Now for what is important:

  • Muscle strengthening and range of motion exercises should be started early and continued at home; these are essential parts of the post-operative rehab program.
  • Early, aggressive therapy is safe and may restore strength faster.
  • Patients can put weight on the leg right after surgery; they can move the knee from a fully straight position up to 90 degrees of flexion.
  • Closed-chain exercises (foot is planted on the floor or solid surface) can be safely started right away after surgery, too.
  • Eccentric quadriceps strengthening and isokinetic hamstring strengthening can be started three weeks after surgery.

    Systematic reviews like this that summarize current evidence around a topic like rehab after ACL reconstruction are important. They help us see trends over time: what works, what doesn’t, and what needs further study. They also help find cost effective ways to speed up recovery and return patients to full function and athletes to full sports participation.