News Category: Knee

Collagen Meniscus Implantation (CMI) is a new treatment for people with damaged, destroyed, or removed knee meniscus. The implant is actually a scaffold made from bovine (cow) Achilles tendons. It has been tried with medial meniscal problems. In this report, surgeons from Italy offer their results in the first published study using collagen meniscus implantation for lateral meniscus injuries.

In each human knee, there are two menisci. One is the lateral meniscus (on the outside of your knee) and the other is the medial meniscus (on the inside of the knee). The menisci are attached to the tibia (lower leg bone) by ligaments. The menisci are important because they act as shock absorbers. They stabilize the knee and allow your body weight to be evenly distributed across the joint. The menisci protect and lubricate the articular cartilage (a separate layer of cartilage right next to the joint).

In the past, damaged menisci causing pain and other joint problems would have just been removed surgically. But when we realized joint degeneration leading to early osteoarthritis develops without the meniscus, surgeons started to repair rather than remove this protective cartilage. Eventually, efforts to replace (not just repair) the cartilage were developed. Collagen meniscus implantation (CMI) is an example of this type of regenerative treatment technique.

The scaffold of bovine tissue developed for this purpose is used to fill partial defects (holes or lesions) in the meniscus. The procedure for lateral meniscus implantation is the same as the one used for medial meniscus implantation. After removing the flapped over or torn piece of meniscus, the remaining meniscus is smoothed and shaped carefully to accept the graft. Tiny holes are drilled around the edges of the defect. This step helps create some bleeding that will aid healing and recovery. Once the implant is placed in the hole, the edges are stitched down to hold it in place.

In this study, 24 patients with irreparable lateral meniscus tears received the CMI treatment. Their ages ranged from 16 years old to 53 years old. Without the CMI treatment, these partial tears would have required removal of the damaged cartilage. The risk of early, degenerative arthritis in this age group is a major reason for the use of this new surgical technique. And the results?

All but one patient experienced significant improvements with decreased pain, better knee joint motion, and improved function. Although the knees were stable, not everyone was able to return to their preinjury level of sports or athletic participation. Clinical measurements and repeat MRIs taken over a two-year period of time showed gradual, progressive improvements right up until the end of the study period.

The MRIs showed a partial (not complete) filling effect with collagen meniscus implantation (CMI) therapy. The reason(s) for this remain unknown. It’s possible that chronic injuries that are not treated soon enough just can’t recover as well as acute (early) meniscal injuries. There may be just too much damage and degeneration to respond in a robust fashion.

Even so, the authors conclude there’s no doubt the use of collagen meniscus implantation is safe and effective for partial lateral meniscal tears. Patients can expect a decrease in their painful symptoms accompanied by an increase in motion and function. Rehab is started right after surgery and continues for a full six-months until full unrestricted activity is resumed.

Can a football player return-to-play after surgery to reconstruct a torn anterior cruciate ligament (ACL)? Is it possible to return and advance to the next level of competition? If not, why not? These are the questions Dr. Kirk A. McCullough and his colleagues from Vanderbilt University Medical Center in Nashville, Tennessee addressed in this study.

They conducted a retrospective study of 157 football athletes to find out some answers. A retrospective study means they studied the players after the injury, surgery, and rehab were all over. That makes sense since they wanted to find out what happens much later in terms of return-to-play. All of the patients were either high school or college level athletes. Only athletes with just an ACL injury (no other cartilage, bone, ligamentous or other soft tissue damage) were included in the study.

Each player was interviewed and asked questions about the position they played before the injury, ability to play after surgery, quality of life, and general activity level. Position played is important because some players (e.g., running back, wide receivers) have to be quick on their feet, changing directions, and using pivoting motions that can be compromised by ACL reconstructive surgery. There is the same concern for other players (e.g., lineman) who are more likely to take hits directly to the knees.

In this study, players who did not return to play football were also asked what factors contributed to that decision. The medical record was reviewed for information about the type of injury sustained, type of tissue graft used to reconstruct the ACL, and any problems or complications after surgery.

There was a natural grouping of players into three subsets: 1) those who did not go back to sports at all, 2) those who returned to the game but in a different position or lower level of performance, and 3) those who returned fully (at their preinjury level). Reasons given for not returning at all included fear; knee symptoms such as pain, stiffness, and swelling; perception that strength and/or speed were not enough for competitive play, and advice from others.

About half of the players were able to return to the game. This compares to about an 80 per cent return rate for professional football players with the same injury. For those who did not return to the field, fear of reinjury was a major factor for the college-level players. Performance-related reasons topped the list for the high-school players. And high school football athletes were more likely to leave the team to pursue other interests (including other sports but also other nonsports activities).

The authors conclude that with as many athletes who suffer ACL injuries, the low rate of return to sports should be investigated further. Their discovery that emotional and psychologic factors (fear, perceptions of poor performance) may play a more important role than previously recognized should also be a topic for future studies.

Basketball players get a lot of attention for their anterior cruciate ligament (ACL) injuries but with over 240 million soccer players, they deserve equal time. And that’s what this study is all about. Surgeons from three large medical centers combined their efforts to investigate the rates of return-to-play and need for further surgery among soccer players.

One-hundred (100) active soccer players (males and females) between the ages of 11 and 53 were included in the study. This was a retrospective study, which means the athletes were contacted after their surgery and rehab to see what kind of results they had. Two-thirds had a bone-patellar-bone graft to reconstruct the anterior cruciate ligament (ACL). The other one-third had a hamstring graft. Information about the type of graft used is always important in these studies to see if it makes a difference in results.

Final, long-term results were measured by looking at number of patients who went back to full sports participation, how many were still actively playing soccer years later, and how many people had to have another knee surgery (either on the injured side or the opposite side).

They found some interesting patterns. First, the graft type (hamstring versus patellar) did NOT make a measurable difference. Second, female soccer players were more likely to experience reinjury or future injuries. Any athlete who injured the nondominant leg was at increased risk for recurrent ACL injuries. That’s because after the injury, they put even more stress and strain on the dominant side — eventually leading to an overuse injury. Slightly more than half of all injuries (57 per cent) affected the dominant leg in these 100 patients.

There was a general trend among all players but especially for the females of declining sports participation over time. In other words, more patients returned to the game and played during the first couple of years after surgery. But by the end of five to seven years, far fewer were engaged in sports play.

The reason(s) for this trend are unknown. The authors suggest that maybe women who finish college and go on to a career and/or family gradually give up sports. Men were more likely to say that fear of reinjury and the trauma and pain of the injury and surgery were the reasons why they did not stick with sports.

The fact that women are actually more likely to experience future injuries (compared with men) may have to do with differences in muscular strength and joint laxity between the sexes. Women tend to have greater joint laxity or looseness. Men tend to have tighter and stronger muscles on either side of the joint to support and protect it.

The authors summarize by suggesting greater emphasis on injury prevention for all soccer players (young and old, male and female). Studies reporting results of ACL injury prevention programs are favorable at this point. Future programs need to pay attention to those athletes at increased risk for ACL reinjuries or opposite leg ACL injuries. Females and athletes injuring the nondominant leg are the first groups to target with a prevention plan.

Whether you have a partially or completely new or old tear of the proximal hamstring muscle, the results of this study will be of interest. The injury may have come from a sporting activity or blunt trauma. Either way you will be wondering: should I have surgery to reattach or repair the problem? How soon should I have the surgery? Does it matter? Will the results be the same compared with letting it heal on its own?

Twenty-six men and 26 women with proximal hamstring avulsion (tears) were included in the study. As with all muscles, the hamstring muscle attaches in two places. A proximal tear means the muscle has pulled away from its attachment at the top where it attaches to the ischial tuberosity (your “sit bones” — the place where the pelvic bone rests on the seat of your chair when you are sitting).

Sometimes this type of injury is treated with rest and activity modification (not doing any movements or activities that stress the proximal hamstring muscle attachment). But this approach can take a very long time for healing to occur. And scar tissue around the healing site can also bind down the sciatic nerve causing numbness or pain.

An alternate treatment approach is surgery. Suture anchors are used to reattach and hold the end of the muscle/tendon back on to the ischial tuberosity where it belongs. If the surgery is done within the first 30-days of the injury, it is considered an acute repair. If the procedure isn’t done until more than one month after the injury, then it qualifies as a chronic repair.

Although this study did not answer all of the questions posed, it did look at results after both acute and chronic repairs of the proximal hamstring muscle. They used patient satisfaction, pain relief, muscle cramps, and function (including return to sports activities and loss of leg control) as the main measures of outcome or results.

Some of the patients tore their hamstring muscles waterskiing, while others injured themselves running, skiing, or playing a variety of sports (e.g., tennis, football, baseball, softball). Return to full sports participation was somewhat dependent on the type of sport and surgeon recommendation. For example, waterskiing was usually not recommended after a hamstring injury for fear of reinjury.

Although this study did not show a significant difference in results between acute and chronic hamstring repairs, the authors still advise or recommend acute (early repair). Strength and function was slightly better (but not statistically significantly better) in the acute repair group.

In the experience of these orthopedic surgeons, the longer you wait to have the hamstring avulsion surgically corrected, the more difficult it is for the surgeon to find the end of the hamstring, pull it back up to the bone, and reattach it. Likewise, the more time that passes between injury and surgery, the greater the risk of injury to the sciatic nerve.

Patients should be told that even with surgery, they may end up with long-term nerve problems, discomfort when sitting, and numbness over the back of the thigh. Some of these complications occur because the inferior gluteal nerve and the sciatic nerve are retracted (pulled aside) to gain access to the hamstring tendon during the repair procedure. Compression (pinching) of or traction (pulling) on any nerve can result in damage to the nerve and subsequent symptoms.

For many years, surgeons have worked to improve and perfect reconstructive surgery for anterior cruciate ligament (ACL) ruptures. Athletes eager to get back to full sports participation were grateful for the opportunity to have the surgery and resume play. But now many years later, surgeons are asking some important questions.

ACL ruptures are surgically reconstructed by using a piece of graft material to replace the torn ligament. The graft is taken from the patient’s own patellar or hamstring tendon. Studies show that the majority (75 to 80 per cent) of athletes return to their preinjury level of sports participation.

But what happens down the road for these individuals? How long does the ACL graft last? What are the chances of the graft rupturing? Why does it rupture? Knowing the risk factors might help patients prevent such an event. Does it really matter which location the graft comes from (patellar tendon or hamstrings)? And finally, what about the other knee? Does having an ACL rupture on one side increase the risk of an ACL tear on the other side?

These questions were addressed by an orthopedic surgeon and his staff from the North Sydney Orthopaedic and Sports Medicine Centre in Australia. They found some answers to these questions from telephone and written surveys their patients completed. There were 755 patients who had an ACL reconstruction and participated in the study.

No one was contacted until at least 15 years had passed from the time of their first ACL surgery. They were asked all sorts of questions about knee function, further injuries to either knee, additional knee surgeries, family history of ACL injuries, activity level, and satisfaction with results of surgery.

Specific information about each patient was collected from their medical records (e.g., age, gender, leg affected, type of graft used, date of injury and date of surgery). They were able to find out all sorts of interesting information about this group of patients.

For example, rupture of the ACL on the other side was less than one per cent per year and most likely to occur between year one and year four after the primary (first) ACL surgery. Patients who had patellar tendon grafts were twice as likely to have an ACL rupture in the opposite leg compared with those patients who had the hamstring graft. The type of graft did not seem to affect the primary ACL repair — ruptures occurred equally between the patellar tendon group and the hamstring group.

ACL grafts survived intact for 97 per cent of the entire group in the first two years. But the risk of rupture increased as time went by. Rupture of the surgical graft affected 11 per cent of the group. When rupture did occur, it was most likely to happen in the first year after the primary surgery. Men and women experienced graft rupture equally.

There was one final bit of information gleaned from this study. Patients with a family history of ACL rupture had double the risk of both ACL graft rupture and rupture of the ACL on the other side.

This is the first study to take a serious look at the risk and risk factors for ACL rupture in the opposite knee after injury and reconstructive surgery to the primary (first) knee affected. Injury of the ACL in the second knee occurs more often than anyone previously suspected.

All the risk factors probably haven’t been identified yet. But graft type (patellar tendon) and age (younger patients) were two of the main risk factors. Younger age is linked with higher activity level and therefore increased risk of injury. Two other possible risk factors that have not been proven yet are: 1) graft size on the surgical side is larger than ACL on the opposite side creating some differences in tension and 2) greater load on the opposite leg as that leg works harder to protect the injured leg.

How will surgeons use this information? First, patients can be screened more carefully for risks that might contribute to rerupture of the surgical graft and ACL rupture on the other side. Second, rehab can be recommended (especially for physically active patients) that addresses both sides to minimize the risk of more injuries. One rehab method already available and proven effective is the use of plyometric exercises.

This type of exercise training involves fast, powerful movements. Athletes use it to improve the functions of the nervous system, generally for the purpose of improving performance in sports.

But anyone can use these techniques — being a sports athlete isn’t a requirement. During plyometric movements the leg muscles are loaded and then contracted in rapid sequence. Plyometric training involves practicing these movements to toughen tissues and train nerve cells with the goal of getting the muscles to contract in a specific pattern in the shortest amount of time.

Surgeons can also use this information to counsel patients what to expect, especially regarding the risk of rerupture of the ACL graft or first-time rupture of the ACL on the opposite side. Identifying and minimizing all modifiable risk factors requires both surgeon and patient participation and cooperation in the process.

A complete tear or avulsion of the proximal hamstring tendon often requires surgery to heal. (Proximal means the tear occurred where the tendon attaches to the pelvis). How well patients recover from this type of surgery is the topic of this study.

Strength, satisfaction with results, return-to-sports participation, and function were the key areas measured. The number of patients involved was small (13) but the follow-up was good (from two up to five years). Each patient tore the hamstring as a result of a traumatic injury during a sporting event.

Surgery was done within two months of the injury for all but one of those athletes. Ages ranged from 26 to 58 years old, so you can see these weren’t just young sports participants. And that makes the findings of this study unique and important. More middle-aged adults are involved in sports and remaining physically active. There are more of these kinds of injuries. And thus a greater need to know the best way to treat future patients based on the results of current treatment. These athlete patients want to know what are their treatment choices and the chances of returning to full function — including return-to-sports.

Tools used to assess results included MRI images (a way to visualize tendon healing), leg circumference (assessing muscle atrophy), goniometer (measuring range of motion), Lower Extremity Functional Scale (LEFS; function), Tegner Activity Scale (physical function and activity), and isokinetic machine (strength). Pain and other symptoms such as numbness or nerve palsy were also evaluated.

The goal of the study was to use these clinical, radiological, and functional means of evaluating patient results after surgery to repair proximal hamstring ruptures. It is a retrospective study meaning the authors took a look back after the treatment had been completed to see how everyone fared.

Here’s what they observed. There were no differences in side-to-side muscle circumference measurements but they found strength was not equal. The surgical side was still only 78 per cent as strong as the normal, uninjured leg. The really unusual finding was that these patients thought the surgical leg was at least 90 per cent as strong as the other leg.

All but one patient was completely satisfied with the results. But the authors knew there were four of the 13 who had poor outcomes so they wondered how this could be. A closer look revealed that perhaps the tests used really didn’t adequately evaluate patient satisfaction — the questions asked might not have given the patients the opportunity needed to express dissatisfaction with their particular results. That is something they intend to investigate more fully in future studies.

Almost half of the group (45 per cent) reported a significant decrease in activity level and sports participation after surgery compared with before the injury. Other studies report a much higher return-to-sports (80 per cent or more). So this is another area where closer study is suggested. Again, the authors suspect the tools used to measure satisfaction and function after surgical repair of this type of injury just might not be the right ones to use.

And finally, MRIs showed a 100 per cent rate of hamstring tendon healing. There were no signs of tendon tears or fraying. In some cases the healing tendon was filling in with a small amount of fat instead of normal collagen tissue. This finding might account for the lower rates of strength and function observed.

The authors concluded that surgical repair of a complete proximal hamstring tendon rupture in athletes of all ages does yield good results. But there were some lingering questions because hamstring function was not completely restored in this group of patients. As noted, this group of researchers intends to continue studying ways to adequately measure outcomes and improve patient results.

The STAR study (which stands for Study of the Treatment of Articular Repair) was started back in the early 2000s by the Genzyme Corporation, an FDA-licensed facility. This laboratory takes patients’ healthy chondrocytes (cartilage tissue) and grows more normal, healthy cells.

The laboratory grown chondrocytes are then used to fill in holes in the joint surface of the knee. These holes or defects occur in the joint surface cartilage and first layer of bone under the cartilage. They are caused by a condition known as osteochondritis dissecans (OCD). The goal of the STAR study was to see how well autologous chondrocyte implantation or ACI works for osteochondritis dissecans (OCD).

There’s an added little twist to the STAR study. And that is — each of the patients included already had one failed surgery for severe (full-thickness) lesions. In this new study, 32 more patients who met these criteria (severe lesions, one failed surgery) were treated with autologous chondrocyte implantation (ACI) and then followed for the next four years. The results of treatment and analysis of factors that might improve treatment were reported on.

Outcomes of treatment were measured based on patient report of pain and other symptoms (swelling, tenderness) as well as activity and function. Activities included return to sports or physical recreation. Function was measured by patients’ perception of their quality of life and ability to perform activities of daily living (walking, climbing stairs, getting up and down, returning to work).

The majority of patients in this STAR study had a successful repair of their severe osteochondritis lesion using autologous chondrocyte implantation (ACI). Although it was two years before the repair tissue was mature enough to mimic normal tissue, patients reported pain relief and functional improvement early on. And those positive results continued for the full four years of the study follow-up period.

Factors that affected outcomes included 1) chronicity of the disease (i.e., how long they had it), 2) severity (how deep and wide were the lesions), 3) delays in treatment, and 4) age (adults versus teens).

As you might expect from the listed factors, the larger the defect and the longer it was present increased the risk of a poor outcome. Likewise, a long delay between diagnosis and treatment is an added predictive factor of worse results. And the timing of treatment is linked with age. Patients who develop OCD in their teen years but aren’t treated until they are adults tend to have a lower success rate than those patients who are treated during their adolescent years.

The results of this study are consistent with the results of other, similar STAR studies. Pain reduction and improved function lasting up to 48 months can be expected after autologous chondrocyte implantation (ACI). Keep in mind the patients in the STAR study have all had one previous failed surgical treatment.

ACI is not the first choice for treatment of osteochondritis dissecans (OCD). But as the STAR study has shown, it is a good “rescue” option when other methods fail for severe, chronic cases.

In today’s evidence-based medicine, patient satisfaction is important but so are measurable outcomes. Finding ways to quantify before and after change in terms of function is also important. In this study, physical therapists compare the reliability and responsiveness of three tools used to measure change in knee function. All patients (168 total) in the study had a diagnosis of knee osteoarthritis.

The three tools compared included the most widely used scale: the Western Ontario and McMaster Universities Osteoarthritis Index or WOMAC. The other two patient surveys were the Knee Outcome Survey (KOS) and the Lower Extremity Functional Scale (LEFS).

Each one of these self-report instruments measures function in slightly different ways. For example, the WOMAC looks at pain during activities, stiffness after prolonged positions, and ability to perform movements like standing up from a sitting position, dressing self, going up and down stairs, and walking. The KOS assesses limitations caused by pain, swelling, and joint instability. The LEFS looks more at the degree-of-difficulty someone has performing specific tasks during activities of daily living.

Everyone in the study completed all three surveys before and after treatment. Treatment consisted of a physical therapy program of leg strengthening, stretching, balance, and agility exercises. The exercise program took place twice a week for six to eight weeks. Patients were followed for up to one-year at regular intervals (two months, six months, 12 months).

The results showed that to measure change in knee function, all three tools are reliable and responsive. Therapists using these self-reported instruments may get slightly different information but all three surveys will reflect change and can therefore be used to obtain outcome measures. There was a trend observed with all three tools: the longer the follow-up, the less reliable the tools were to measure patients’ responsiveness to treatment.

There may be some specific reasons for this trend. For example, as people improve there may be less change occurring making it more difficult to measure change with these particular questions. There may also be differences in patient osteoarthritis that contribute to reduced observations of change. For example, someone with acute arthritis versus someone with a chronic condition may not respond to treatment in the same way. More studies are needed to examine these factors more closely.

With the use of arthroscopic examination, surgeons can prove and refine clinical tests for joint damage. In the case of the meniscus, a C- or horseshoe-shaped piece of cartilage in the knee, the McMurray test is used most often to diagnose posterior (along the back of the knee joint) meniscal tears. Results of the McMurray can be verified during the arthroscopic exam when the surgeon can perform the same test and see what happens to the meniscus.

There are two McMurray tests: the standard or conventional McMurray and the paradoxical McMurray. Both tests are performed in the same way. The knee is bent; the examiner holds the heel and twists the lower leg in and out. If there is a torn or loose meniscus, there will be a painful, snapping or clicking sensation as the movement shifts or traps the meniscal flap or fragment between the tibia (lower leg bone) and the femur (thigh bone).

The results are what make the test conventional or paradoxical. For example, the test is considered “paradoxical” when the leg is rotated internally (inward) and the medial side of the knee (side closest to the other leg) clicks. There can also be a paradoxical McMurray when the leg is rotated externally (outward) and the clicking occurs in the lateral compartment (or side) of the knee. Lateral refers to the side of the knee away from the other knee.

The results just described are considered paradoxical, meaning the opposite of what is expected. In the conventional test, the clicking occurs on the opposite side of the knee from the rotation. When the leg is rotated inward, the clicking occurs on the outside of the knee. When the knee is rotated outward, the clicking occurs on the inside of the knee.

In this study, one surgeon compared each test before and during arthroscopy in two groups of patients. Group one had a confirmed meniscal tear. Group two did NOT have a meniscal tear. There were a total of 1,015 patients who had knee arthroscopy. Two thirds of the group had a meniscal tear. The remaining one-third did not have a meniscal tear.

This type of study gives us a better idea of how accurate the tests are. In statistical terms, sensitivity and specificity of each test is determined. Sensitivity refers to a “true positive” test — in other words, when the test is positive, it is a true indication that the person has a meniscal tear. Specificity refers to a “true negative” test — when the test is negative, the person really doesn’t have a meniscal tear.

The more sensitive a test is, the fewer false positives are found. A false positive is when the test is positive suggesting a meniscal tear is present when, in fact, there is no tear. The more specific a test is, the fewer the false negatives. A false negative refers to the patient who has a negative McMurray test as if nothing is wrong when there really is a meniscal tear present.

So, how did the two tests compare in terms of sensitivity and specificity? The paradoxical McMurray was much less sensitive (less able to find patients who really have a torn meniscus) compared with the conventional McMurray test. But the paradoxical test was more specific (when the test was negative, the person did not have a meniscal tear).

The surgeon also looked at types of meniscal tears to see if some types are more likely to show up on one test versus the other. Types of tears are categorized based on the location and/or shape of the tear (e.g., lengthwise versus crosswise or tear versus detachment). He was able to see why sometimes the paradoxical test was accurate and sometimes inaccurate. If the tear was not long enough or located in the middle of the meniscus, the paradoxical test would be negative.

The author suggests an MRI should be ordered when the paradoxical McMurray test is negative but the patient has pain and other clues pointing to a meniscus problem. A positive paradoxical test is a sign that there is a large meniscal tear — long enough to shift the loose or torn meniscus during the test. But a positive paradoxical McMurray test does not mean the patient should have surgery immediately. The surgeon must evaluate the patient history and clinical findings and find out the patient’s goals and activity level.

In this systematic review, surgeons from the Department of Orthopaedic Surgery and Sports Medicine at the University of Kentucky found 25 articles on the subject of medial patellofemoral ligament (MPFL) reconstruction. Their interest was in reporting on the various ways to do this surgery and the rate of complications.

This information is important in helping surgeons improve treatment and results for the many athletes who are affected by injury to this ligament. A little bit of anatomy will help explain this injury. Let’s start with the patella — more commonly known as the “kneecap”. The patella moves up and down in front of the knee joint along a built-in track called the patellofemoral groove.

The kneecap is held in place by several ligaments on either side and by the patellar tendon (attached to the quadriceps muscle). The quadriceps muscle is the large, four-part muscle along the front of the thigh.

Although you can take your hands and passively move the kneecap from side to side, this is not an active movement you can make your patella do without assistance. We call that side-to-side (medial-to-lateral) movement accessory motion. The up-and-down and side-to-side accessory motions are referred to as patellar glide.

As part of the patellar tendon, there are slips of ligamentous fibers that help hold the patella in place and keep it from moving too far to one side or the other. On the inside of the kneecap is the medial patellofemoral ligament. On the outside is the lateral patellofemoral ligament.

Without the medial patellofemoral ligament, the kneecap dislocates laterally (in a direction sideways away from the other knee). Because the medial patellofemoral ligament is connected with other ligamentous structures, complete rupture will likely damage other areas as well. The medial patellofemoral ligament attaches above to the femur (thigh bone) and below to the tibia (lower leg bone).

When this ligament is torn, surgery to repair or reconstruct it may be needed. But there are many different ways to accomplish this and no one way known to have the best results for everyone. Looking at results reported for different graft choices, graft tension, and fixation methods (ways to attach the graft in place) will help surgeons find better ways to stabilize the knee and prevent a disabling condition for these young athletes.

The choice of articles to review was limited because some reports were just case studies (small groups of patients) while others were done on cadavers (rather than with live patients). Of the studies that qualified to be included, there was a 26.1 per cent complication rate. The procedure was a success but the complication rate was considered significant. This figure represents an overall complication rate from all the studies combined. Rates actually ranged from zero (no complications) up to 85 per cent.

Taking a closer look at the specific complications, there were patellar fractures, patellar instability, loss of knee motion, pain, infection, and other wound complications. Twenty-six of the 629 knees treated surgically required an additional surgical procedure. The most common revision surgeries were to remove bothersome hardware or manipulate (move) the joint to restore motion. Three per cent of the total number were classified as “failures” due to ongoing instability and persistent patellar dislocation.

What conclusions did the authors come to from the results of their analysis?

Exercise recommendations for people with knee osteoarthritis suggest the following:

Activities associated with an Oriental lifestyle such as squatting during daily activities and the Lotus position have been considered potential risk factors for medial meniscal tears of the knee. In assuming the Lotus position, the feet are placed on the opposing thighs. It is a posture commonly used for meditation in the Hindu Yoga and Buddhist traditions. The position is said to resemble a lotus flower to encourage proper meditative breathing.

In this study, orthopedic surgeons examined 476 patients who had an arthroscopic exam for meniscal tears and analyzed whether a posterior root tear might be linked to these two positions.

The posterior root of the medial meniscus sounds like a mouthful but it really just describes the back corner of the meniscus. And specifically on the side of the knee closest to the other knee. This type of meniscal tear results in a piece of cartilage that is separated into two pieces but only attached to the bone (tibia) at one end.

Because of its location, the stress placed on this part of the meniscus could conceivably be greatest when the knee is in the extreme positions of flexion required in the squatting position. The same goes for the flexion and rotation required by the Lotus position.

But as it turns out, when they compared patients with medial meniscus posterior root tears (MMPRTs) with patients who had other types of meniscal tears, these two positions did not increase the risk for MMPRTs.

Of course, the researchers didn’t just look at positions when checking for potential risk factors. They collected a wide range of data including patient age, sex, body mass index (BMI), findings on X-rays, activity level, occupation, previous injuries, and use of a bed or table.

What they found was that it’s mostly intrinsic factors (not lifestyle) that make a difference. The four intrinsic risk factors with the greatest impact on MMPRTs included: increased age (older than 50 years of age), female sex, being overweight (higher BMI), and lower level of sports activity. The mechanical angle of the knee (as seen on X-rays) was one anatomic feature that also increased the risk of MMPRTs.

This study brought to our attention the importance of these risk factors. In the bigger picture, these risks are important because we know that meniscal tears can leave a person at risk for early knee osteoarthritis. Knowing what the risk factors are for the tears might help us find better ways to prevent these injuries in the first place. And that would mean reducing the risk of early degenerative knee osteoarthritis. It’s a double win-win situation.

The fact that positions often used by Oriental people did not contribute to the posterior corner tears of the medial meniscus may be because the knee structure adapt to these positions when used from an early age on. We do not know if this type of injury occurs more often in those individuals who begin using these positions later in life.

Significant (deep and wide) injury to the cartilage lining the surface of the knee joint can be treated with a transplantation of cartilage cells called chondrocytes. The transplanted chondrocytes usually come from the patient’s own knee — from another area that has little weight put on it. The procedure is called an autologous chondrocyte implantation or ACI.

Once the donor cells have been harvested, they are taken to a lab where more cells can be produced from the graft. When ready, the cells are placed in the defect (hole) and then covered over with a patch. The patch can be made of bone (the outer layer of bone called the periosteum) or it can be made of collagen. Collagen is the basic protein building block that makes up most soft tissue.

Collagen patches are available in the United States and approved for use by the Food and Drug Administration (FDA) but not for knee cartilage repairs. Right now they are only approved for rotator cuff repairs, tendon reconstruction surgery, and dental procedures. When used as a patch for autologous chondrocyte implantation, it is considered an “off-label” use. European surgeons have unlimited approved use of the ACI-collagen patches for chondral repair.

In order to study the use of ACI-collagen patches and compare them to ACI-periosteal patches, surgeons from the University of Nebraska Medical Center conducted this study. They were mainly interested in knowing if there is any cost savings in using the ACI-collagen over the ACI-periosteum.

One way to judge that is by observing how many patients end up having a second (revision) surgery after the first transplantation. The primary reason revision surgery is done after ACI-periosteal grafts is because of hypertrophy (overgrowth of the bone). The surgeon ends up going back in and shaving away the excess bone. This type of complication is much less likely with the ACI-collagen patches.

By following two groups of patients (one group received the ACI-collagen patch, the second group had the ACI-periosteal patch) for 10 years, they made one important discovery. The ACI-collagen patch cost about $1000 more (per patient) but there were far fewer cases of second surgeries needed for graft hypertrophy or graft failure in the collagen group.

Other studies have reported a rate of graft hypertrophy as being around 25 per cent for patients receiving an ACI-periosteal patch. This compares with a 10 per cent rate linked with the ACI-collagen patch.

That information added to the fact that a second surgery costs about $8300 more suggests the ACI-collagen patch may be worth the added investment up front to avoid future costs associated with failure or hypertrophy. And that $8300 figure is based on current costs for hospital, surgeon, and anesthesiologist. Surgeries that take place several years down the road will likely cost more.

The authors conclude that the ACI-collagen patch for significant knee articular cartilage lesions is cost-effective. There is already evidence to show that half of all ACI procedures are already being done with the collagen product instead of the periosteum. Since the collagen patch has not been approved yet by the FDA for this type of problem, this study may help provide the evidence needed to support FDA approval in the near future.

Degenerative knee osteoarthritis (OA) can be treated with physical therapy, medications, or surgery when appropriate. The focus of this study was the effectiveness of arthroscopic surgery for knee OA. The specific procedure studied is called debridement.

The surgeon shaves away any uneven areas of the joint surface and smoothes any jagged edges in the cartilage. If there are any loose fragments in the joint, these are removed as well. Joint swelling, stiffness, and pain are believed to improve with this treatment but the effect of debridement in the actual degenerative process itself is unknown.

What we do know from studies so far is that knee arthroscopic debridement reduces pain and improves knee function for up to five years or more. Now with the results of this study, we have another piece of information about results using arthroscopic debridement based on the severity of the OA.

All participants in the study were adults 45 years old or older with a diagnosis of Grade II or Grade III osteoarthritis of the knee (on a scale from I to IV). These grades are based on X-ray findings of severity of the condition. Some, but not all, of the patients were overweight, which may be a contributing factor to the development of OA.

Using arthroscopic debridement, the surgeon removed loose fragments of tissue (e.g., bone spur, pieces of meniscus). A saline solution was used to flush any remaining debris from the joint.

Everyone was followed at regular intervals for two years. Patients with grade II (less severe) OA did just fine with this type of treatment. But patients with grade II (more severe) OA did not fare as well. X-rays showed ongoing joint degeneration within the year following the debridement procedure in the patients with grade III OA. These patients did experience improvements in symptoms (less stiffness, less pain, more motion) but they were unable to maintain the results.

Arthroscopic debridement is considered a stop-gap measure. It seems to yield the best results when the disease has just started and the joint surface is not damaged or worn unevenly. Treatment of this kind is also more likely to be successful when the patient is not overweight. Patients who exercised and strengthened the legs also had better results.

The authors still recommend the use of arthroscopic debridement for grades II and III osteoarthritis. Patients should be informed that the results may be temporary but could buy them some time before needing a knee replacement.

There is no cure for chronic pain caused by knee osteoarthritis. But there are ways to help reduce the pain and improve function. Physical therapy modalities such as diathermy, interferential current, electrical stimulation, and exercise can be very helpful.

To help support this statement a group of researchers from four different health care centers in Turkey conducted this study. They compared the effectiveness of each of these treatment tools. They used pain levels, measures of stiffness, ability to walk 15 meters, range of motion, and use of pain medications as measures of outcomes for 203 patients.

The patients were divided randomly into one of six groups. There were three active treatment groups (transcutaneous electrical stimulation or TENS), interferential current or IFC, diathermy) and three “sham” groups. TENS and IFC provide an electrical current designed to inhibit pain messages from going up the spinal cord to the brain. Diathermy is a form of electromagnetic therapy that produces heat deep in the soft tissues.

No one administering the treatment or receiving the treatment knew whether the treatment was real or a sham. The combination of random assignment and lack of knowledge of the treatment type makes this study a randomized, double-blind, controlled study.

Everyone in the six treatment groups received their therapy every day Monday through Friday for three weeks. They also received education and exercise from their therapists making the overall treatment approach a multimodal one (in other words, a group of different treatments combined together).

Comparing their measurements before and after treatment they found that everyone in all six groups made significant improvements. The use of Tylenol was much lower in the true physical therapy groups and much higher in the sham treatment groups. There did not appear to be any difference among the different modalities. TENS, IFC, and diathermy all delivered the same amount of pain relief.

In summary, the results of this study show that a combination of physical therapy modality, education, and exercise gives the best improvements in patients with chronic pain, stiffness, and loss of function from knee osteoarthritis. Education and exercise provided more improvements in pain and function up to six months. The use of modalities seemed to give the most improvements in the first three months following treatment.

Regenerative medicine is a relatively new term you may start hearing more about. It refers to finding ways to help the body heal itself at the cellular level. For example, tissue from an uninjured part of the knee cartilage can be used to grow more chondrocytes (cartilage cells). Platelet-rich plasma (PRP) is another form of regenerative medicine and the topic of this new study from the OASI Bioresearch Foundation in Milan, Italy.

Platelet-rich plasma (PRP) (also known as blood injection therapy) is a medical treatment being used for a wide range of musculoskeletal problems. PRP refers to a sample of serum (blood) plasma that has as much as four times more than the normal amount of platelets. 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.

Using platelet-rich plasma to encourage tissue regeneration in the hyaline cartilage of the knee may be a new way to prevent or slow down the degenerative process that leads to osteoarthritis. Hyaline tissue is the type of cartilage that lines the inside of the knee joint.

The hyaline cartilage has many wonderful characteristics. It allows the knee joint to move without friction. It protects the bone underneath the cartilage from too much load and trauma. Hyaline cartilage also spreads out the forces placed on the knee joint during movement. But the one thing it does not have is a rich supply of blood. Injury or damage to the hyaline cartilage sets off a series of events that can lead to degeneration and osteoarthritis.

Who gets these kinds of knee injuries? And who can benefit from platelet-rich plasma injections to treat the problem? Many people of all ages who are physically active and especially participating in sports suffer from chondral injuries. And increasing age combined with chondral defects or injuries is a recipe for painful knee symptoms linked to osteoarthritis.

That’s where platelet-rich plasma comes in. It has been used for years after plastic surgery and surgery on the mouth, jaw, and neck. It seems to promote and speed up healing. Anywhere from two to six times the number of platelets with their growth factors are released into the injured area.

Blood injection therapy of this type has been used for knee osteoarthritis, degenerative cartilage, spinal fusion, bone fractures that don’t heal, and poor wound healing. This treatment technique is fairly new in the sports medicine treatment of musculoskeletal problems, but gaining popularity quickly.

In this study, two groups of patients with osteoarthritis of the knee were given two injections of platelet-rich plasma (PRP). Conservative (nonoperative care) with anti-inflammatory medications had been tried for at least three months with no improvement in symptoms.

One group (25 patients) had previous surgery for the damaged knee cartilage (either a shaving procedure called debridement or a procedure called microfracture). Microfracture is the use of tiny holes drilled through the cartilage and bone to stimulate bleeding and healing. The other group (25 patients) did not have any knee surgery prior to the blood injection therapy.

Results for the two groups were compared by looking at pain, function, and quality of life. A variety of tests were used to collect information to measure these outcomes. All measures were taken before platelet-rich plasma injection (baseline), six months after the injections, and again one-year after injection therapy. Results were also compared between men and women to see if there was a sex-linked difference in treatment results.

They found no difference in results between the two groups or between the sexes. It seems everyone in the study benefitted and improved with this treatment approach. There was a positive effect of PRP in active patients with painful knee osteoarthritis. There were no differences between men and women and no adverse reactions or complications for anyone.

The post-operative program included the use of local ice held on the knee for 20 minutes every two to three hours for a 24-hour period. Patients were advised to tone down their level of activity and avoid vigorous use of the knee for at least 48 hours. They were allowed to put weight on the injected knee as tolerated (usually determined by pain levels).

In summary, using platelet-rich plasma (PRP) to stimulate the natural healing process and regenerate hyaline cartilage may be an acceptable way to treat damaged hyaline joint cartilage. This study provides some evidence that PRP can be used in active adults with cartilage lesions to prevent progression of osteoarthritis — even for patients who have already had cartilage surgery (cartilage shaving or microfracture).

The authors point out that they used two PRP injections but there may be a more optimal number of injections required. Further research is needed to develop specific standardized treatment protocols. Likewise, studies are needed to find ways to predict how much PRP is needed for each type of tissue damage. Long-term studies (following patients for more than 12 months) are recommended.

Here’s something running backs, wide receivers, rugby players, and ballet dancers have in common: hamstring strains. In fact, acute hamstring strains may be the second most common injury among this group. Only knee injuries top hamstring-related injuries for taking a player or dancer out of commission.

Given the high rate of hamstring injuries, there is a great deal of interest among sports physical therapists in helping these athletes rehabilitate and return to their sport or performance. In order to do that, an accurate diagnosis is important. But identifying risk factors and predictive factors for injury and reinjury is important.

Studies done so far show that athletes who have injured their hamstring tendon or muscle are twice as likely to reinjure the same tendon/muscle. The older you are and the more you weigh, the higher the risk for a hamstring tear. But weak hamstrings, imbalance in leg muscle strength, and tight hip flexors also increase the risk of a hamstring strain.

What can be done to help these athletes get back to their sports, dance, or other desired athletic activities? The first thing NOT to do is stretch the acutely injured tissue. With the hamstrings (a muscle all athletes spend time stretching), stretching after an acute injury only lengthens the time it takes to get back into action.

Stretching does not seem to lengthen muscle fibers during the healing process. Scar tissue forms as part of the natural healing process. And that scar tissue links up with muscle fibers causing stiffness in the tendon-muscle unit. Researchers are still looking for better ways to lengthen injured/healing hamstring tissue.

In the meantime, studies show it makes much more sense to focus on core training, which will increase trunk stabilization and greatly reduce the risk of reinjury. Agility training is another valuable approach in preventing hamstring reinjury. Eccentric training (starting with the muscle contracted and in a shortened position and moving into positions of elongating the tissue) has some benefit but remains under investigation.

The approach to treatment of acute hamstring tendon/muscle injuries depends on the type and extent of injury. A strain or sprain is different from a full or even partial rupture. Sometimes the tendon pulls away from the bone where it attaches, taking a piece of the bone with it. These are called avulsion injuries and may require surgery.

In order to make a decision about the best treatment approach, an orthopedic surgeon performs various clinical tests and orders imaging studies. X-rays, ultrasound, and MRIs often offer the best diagnostic information with hamstring injuries.

Bleeding into and around the muscle is common with avulsion injuries. Pressure on the sciatic nerve from blood in the area can cause a tingling sensation along the back of the thigh. Surgery may be needed to repair the torn tissue and remove the pressure from the nerve. Hamstring tendons that have retracted pulled away from the bone by more than 2.5 to 3.0 cm (1/4 to 1/2 inch) are especially likely to need surgical repair.

Other less severe strains or hamstring tendinopathymay respond to conservative (nonoperative) care. Tendinopathy refers to a chronic injury with reactive edema (swelling), thickening of the tissue, and scarring but no active inflammation. Care is usually provided by a physical therapist who will focus on posture, alignment, core strengthening, and soft tissue mobilization. When appropriate hamstring stretching and strengthening may be included in the program.

Safe return-to-sports, dance, or other athletic activities may take some time. Reinjury is always a concern. With acute injuries, the ability to walk without pain is actually very predictive of return to activity. Athletes who can walk pain free within 24-hours of the injury are four times more likely to return-to-sport/activity quickly.

One test that has proven reliable in predicting safe return to activity is called the active hamstring flexibility test. The athlete lies on his or her back with one leg in a knee extension splint. The splinted leg is quickly lifted up off the table as far as it will go. The test is done on both legs. The amount of hip flexion is measured and compared from side-to-side. Equal movement without pain or apprehension in the presence of normal hamstring strength is a good sign the athlete is ready to return to the field or stage.

It’s pretty hard to run, twist, jump, and compete as an athlete when you have chronic lower leg (below the knee) pain. And that condition accounts for more leg problems than anything else (other than knee pain) in both competitive and recreational athletes.

With all the improvements in diagnostic testing and available evidence out there, the authors of this article (two physicians from Vanderbilt Orthopaedic Institute in Nashville, Tennessee) decided to do a literature search on chronic lower leg pain. They hoped to find evidence to support and guide a standard diagnostic and treatment approach to this problem.

Their search extended from January 1980 to May 2011 and uncovered five common causes of lower leg pain in athletes. These conditions include 1) medial tibial stress syndrome (shin splints), 2) chronic exertional compartment syndrome, 3) stress fracture, 4) nerve entrapment, and 5) popliteal artery entrapment syndrome. Long-distance runners and military personnel seem to have the most lower leg injuries.

The authors provide a brief review of each of these five conditions, the most common causes of these injuries, and current recommendations for treatment. They state at the beginning of the article that the evidence for a standard approach to these problems in athletes is “sparse.”

All five of these chronic lower leg pain problems are caused by weight bearing, repetitive or compressive forces, and overexertion or overuse from activities such as running. Continuing activities that bring on leg pain or make leg pain worse is an important risk factor for acute pain becoming chronic (long-term).

Other risk factors for these conditions include female sex, anatomy (e.g., flat feet, hip internal rotation), and previous injuries. Eating disorders and loss of bone density are additional risk factors for bone fractures. And being overweight contributes to delays in recovery. Continued exercise and overtraining resulting in increased muscle bulk can lead to impingement (pinching) of a nerve or blood vessel (entrapment).

Before treatment can be determined, an accurate diagnosis must be made. The physician starts with a good patient history including training history (number of sessions per week, length of each session, intensity of sporting activity), training surface, and footwear. Any recent changes in any of these variables may be an important part of the history.

Depending on the patient’s symptoms, diagnostic imaging can include X-rays, bone scans, and/or MRIs. For more specific identification of problems involving compartment syndromes, pressure testing can be done. To test for nerve compression, electrodiagnostic studies can be ordered. The diagnosis helps direct treatment.

Most often, conservative (nonoperative) care is the first line of treatment. Recommendations for conservative care include rest, the use of ice, antiinflammatory medications, and possibly taping, splinting or casting the lower leg.

Physical therapy is an important part of the recovery and rehabilitation for these athletes. The therapist will address posture and alignment, flexibility and stretching, activity modification, and strengthening. The therapist is also integral in guiding the athlete in selecting proper shoe wear and getting back into an appropriate and effective training schedule.

Some conditions such as stress fractures, requires rest before rehab. The athlete is put on crutches and a nonweight-bearing status. Load is taken off the bone until healing can take place. This means no sports or recreational activities until cleared by the physician.

Other problems such as entrapment syndromes affecting blood vessels require more immediate surgical attention. Surgery may also be needed for athletes with some of these other problems that do not respond to conservative care. The athlete who requires surgery can expect a longer period of recovery and gradual return-to-sports through rehabilitation. Impact and sports-specific training is essential following surgery for any of these conditions.

The authors conclude that chronic leg pain in competitive and recreational athletes is common, often develops slowly over time, and is ignored too long before diagnosis and treatment. The diagnosis can be difficult and requires patience in taking a complete history and performing the clinical examination. Right now, there is no evidence-based standard of care for these problems. More studies are needed to provide evidence to guide physicians in these cases.

With more and more young and active adults of all ages developing knee osteoarthritis, there is a need for a long-lasting, durable knee replacement implant. Different implant designs have been developed and tried over the years. Some are held in place with cement. Others are cementless. There are unicompartmental implants, rotating-platform implants, and fixed or mobile bearing. Some implants have polyethylene (plastic) backing while others are all metal.

In this study, 10-year results with the rotating-platform, posterior-stabilized implant are reported. Specifically, one surgeon implanted 106 knees with the Press Fit Condylar (PFC) Sigma rotating-platform posterior-stabilized knee. Rotating platform implants are designed for longer life with less wear for the young, active, or overweight patient.

In a mobile-bearing knee, the polyethylene insert in the tibial (bottom half) component can rotate short distances inside the metal tibial tray. This rotation gives more rotation from side to side. In order to be a good candidate for this type of implant, the patient must have strong ligaments around the knee to support the implant. A stable joint is less likely to dislocate.

Up until now, there have been no studies that show mobile-bearing implants as the preferred choice for durability, improvement in pain, or improvement of function compared with a fixed-bearing design. Now with 10-years of data, there is a better idea of how well the PFC Sigma design works and holds up.

Patients ranged in age from 34 to 88 years old. Osteoarthritis of the knee was the main diagnosis for almost everyone in the study. Results were measured using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Knee Society pain score and functional score. X-rays and patient satisfaction regarding ability to perform daily activities and participate in sports or recreational activities were also used to measure outcomes.

Analysis of the data showed there was good to excellent results with significant improvements in pain and function. In fact, all of the implants were still in place at the end of 10 years, suggesting good long-term implant survival. Only a handful of patients had to have revision surgery for any reason. There were no implant failures caused by bone osteolysis (absorption or dissolving of bone) or implant loosening.

There were some reports of knee pain (14 per cent of the group) and crepitation (crackling sensation heard and/or felt). The authors recommend further study to find out what is causing these residual symptoms. For now, it looks like the PFC Sigma rotating-platform, posterior-stabilized design showed itself to be an excellent choice for durability and stability over time.

The rotational design and close fit of the components of this implant reduce cross shear forces. This, in turn, decreases wear and increases survival rates. Although this particular implant is usually reserved for young or active older patients, it was used quite successfully in this study with people of all ages.

In this study from Italy, orthopedic surgeons transplanted donor menisci (plural for meniscus) in the knee of 32 patients and then reported the results over the next three years. Allografts (donor menisci) were used. And they used a specific technique of suturing the graft cartilage that was different from other studies.

Instead of taking plugs of bone and using them like pegs to hold the donor graft cartilage in place, they used sutures. But that wasn’t what made their surgical approach so unique. They also secured or “fixed” the graft to the anterior capsule (anterior means front, capsule refers to the cartilage and connective tissue that forms a cap around the knee).

In other studies, surgeons either used bone plugs or sutured the graft to the anatomic or original insertion point on the tibia (lower leg bone). But the authors say their technique is faster and easier. And now their results show the outcomes are just as good as other methods of graft fixation. They suggest that the best way to get optimal results with meniscal transplantation is to select the correct graft size for each patient, place the graft anatomically, and secure it in a way that promotes biologic healing.

By fixing the sutures to the front of the tibial plateau, they were also able to make a single tunnel through the tibial bone using an arthroscope. With this approach, they could also complete all suturing inside the joint, referred to as an all-inside method of fixation. There is less disruption to the soft tissues of the knee with this method, which could also promote faster healing and recovery.

But how do the results match up with other techniques (e.g., using bone plugs instead of sutures, placement of the sutures in the anatomic location)? Using pain, knee motion, and function as the main measures of results, they found significant improvements in 94 per cent of the patients in their group. There was reduced pain and improved knee function still present three years after the procedure.

Magnetic resonance imaging also showed this surgical method offered a protective effect to the bone underneath the transplanted cartilage. This is referred to as a chondroprotective effect. The only concern was for the graft extrusion observed on MRIs in two-thirds of the group.

Extrusion of the graft refers to pushing of a part of the graft material out of the knee joint cavity. This extrusion was more common in grafts on the lateral side of the knee (the side away from the other knee). There did not appear to be any effect of this extrusion on patient pain or function — at least not in the short-term. Long-term studies may show a different result.

No one knows exactly why graft extrusion occurs. But it is commonly reported in all studies involving meniscal transplantations. Experts suggest a variety of possible reasons for this problem. The fact that the lateral side pushes out more often than the medial side (side closest to the other knee) suggests factors involving biomechanics and load distribution.

But it could be there are effects of surgical technique from putting too much tension on the sutures, using a graft that’s too large for the space (called “overstuffing”), or when the sutures do not reattach the graft at the anatomical location (where the meniscus normally inserts into the bone).

Given the short-term success of this surgical technique, the authors suggest a longer study to follow these patients 10 years or more. A longer period of time would help show whether or not there is a true chondroprotective effect of meniscal allografts. Future studies could also compare allografts implanted this way versus implants secured with bone plugs. Comparing different types of MRIs (e.g., taken while lying down versus standing on one leg or both legs) might also offer some additional information.