FAQ Category: Knee

That’s a good question and one that has been asked by many patients and surgeons alike. In fact, many studies have already been done on this topic. Researchers have been trying for years to figure out just when, how, and why immobilizers should be used after an anterior cruciate ligament (ACL) repair or reconstruction.

Part of the problem in coming to a definite answer lies in the fact that there are all kinds of knee immobilizers and braces. They can be worn for different periods of time and for different reasons. Some surgeons use them to protect the healing graft. Others use them to help control pain. With different variables measured from study to study, it’s difficult to come up with a firm conclusion about immobilizing the knee after ACL repair.

In a recent study from Canada, two groups of patients with ACL repair were compared. One group wore a soft, unhinged knee immobilizer for two weeks after the surgical procedure. The second group did not wear an immobilizer. The main measure of brace effectiveness was pain in the first two days after surgery.

The researchers also took a look at how much (and what kind) of pain relievers were used during the first two days up to the first two weeks after surgery. They didn’t find any differences between the two groups. They came to the conclusion that at least for pain control after ACL repairs with a hamstring graft, an unhinged knee immobilizer isn’t needed postoperatively.

It’s possible that some other type of immobilization would be more effective. Perhaps using a hinged knee brace would appeal to patients more and improve compliance. The authors suggested trying a hinged knee brace in a future study. Patients could lock it at night to protect joint motion and wear it hinged during the day to allow motion.

Since the group that wasn’t immobilized at all had the same results, it’s logical to conclude immobilization has no added benefit when used for pain control. Other studies are needed to address concerns about the need for bracing postoperatively for other reasons such as knee stability or graft protection.

Patients often report problems with knee immobilizers slipping down or twisting around the leg. Although the device has vertical metal bars for support and Velcro® straps to hold it on, the fit is not always perfect. Individuals who are thin especially have a difficult time getting a good fit.

Sometimes the type of clothing fabric worn under the immobilizer makes a difference. Smooth or slippery material should be avoided. Jean material tends to bunch up and can cause a poor fit. Most teens find that sweatpants work well. The soft material conforms better to the leg giving the immobilizer better contact.

Sometimes with adolescents, it’s more a matter of how it looks than how it feels. They may be self-conscious or don’t want the hassle of putting it on or off. Talk with the surgeon about this situation. Find out the reason he or she wants your son to wear it. If it’s a matter of pain control and your son can go without it, then maybe, it’s not really needed. But if the surgeon is trying to protect the graft site to ensure a successful procedure, then it may help your son to know that.

There are other bracing alternatives. If it’s a matter of a poor fit, then a different size or style might work better. Again, some of this depends on the surgeon’s reasons for recommending bracing. Usually, the soft, unhinged (all one piece) braces limit all knee motion.

A different approach might be to use functional bracing. This type of immobilizer is a hinged brace designed to allow flexion and extension, but not rotation. The brace is made of stiffer material than the unhinged immobilizer and has thin metal bars on either side of the knee to allow motion but prevent rotation.

Call the surgeon’s office and let them know your situation and your questions. It’s likely an acceptable solution can be found with a minimal amount of distress for you and for your son.

In this case nonrepairable may mean the ligament is too damaged to repair and reattach it. Instead reconstruction surgery is needed. A piece of tendon from some other part of the patient’s own knee (either the patellar tendon or the hamstrings) is harvested and used as a donor ligament.

Years and years ago, a torn anterior cruciate ligament (ACL) might have been removed and considered nonrepairable, but today, reconstruction can be done instead. No doubt your daughter will have a follow-up appointment with the surgeon at which time her treatment options will be discussed.

Today, surgeons can do an arthroscopic exam (passing a very fine needle with a tiny TV camera on the end into the joint) and see directly what’s going on. The exact location and degree of the ligament tear can be seen. Any other damage to the knee (e.g., other ligament tears, meniscal tears) can also be evaluated. Reconstruction usually refers to restoring the ACL along with repairing any other damage present.

If you are unable to attend the next visit with your daughter, consider a telephone consult with the physician in order to understand test results and treatment recommendations. This will give you a chance to ask any other questions that come to mind as well.

Despite many, many studies on this topic, there isn’t one single definitive answer to the question. As more surgical techniques are developed and as the current techniques are improved, patient results also improve.

Today, advanced technology makes it possible to make the diagnosis sooner and with greater accuracy. CT scans, MRIs, and even new clinical tests are available. Surgeons can perform an arthroscopic exam to see exactly what’s wrong and to make the most accurate diagnosis.

The location of the tear and the degree (partial or complete) of injury make a difference in the treatment. A sprain or even a partial tear can still be treated successfully with nonoperative care. The ligament doesn’t repair itself but pretty good results are possible as scar tissue fills in to stabilize the injury. At the same time, the patient completes a rehab program to strengthen the muscles around the knee further protecting the joint from instability and reinjury.

The long-term results of ACL injuries vary based on the age of the patient at the time of the injury/repair, the type of treatment (surgical versus conservative care), and the type of procedure when surgery is done.

But from what has been reported, it looks like partial tears treated nonoperatively had at least a 50-50 chance of good or excellent results. And those statistics are the same as for a surgical repair from 30 years ago. So, given the data we have from patients like yourself, it looks like you had potentially equal results not having the surgery as you might have had with surgery.

Today’s patients may have the same treatment choices, but the overall results are better. And patients who opt for the conservative (nonoperative) approach still have the option of converting over to surgical reconstruction at a later date with equally good outcomes.

Swelling along the backside of the knee could be caused by a few things. There could be some damage inside the joint causing effusion (excess fluid or swelling). There may be a torn ligament or damage to the meniscus (joint cartilage). Have you experienced trauma or some type of injury that could be causing this swelling?

Your general practitioner will conduct a history and physical exam (H&PE) to determine the cause of the problem. Questions about your symptoms and any events leading up to this swelling will help the physician identify the underlying pathology. That’s the history part. Some special tests might be done to rule out internal derangement (damage within the joint). That’s the physical exam portion of the diagnostic evaluation.

One of those tests is just palpating (pressing and feeling) the back of the knee. One of the most common causes of swelling in this area is a Baker’s cyst. This is just a fluid filled sac that forms when a tiny tear in the synovial lining allows synovial fluid to leak out. It’s considered benign or harmless, though it can cause pain when it is pressed or pinched. If enough fluid builds up, it can press on nerves in that area or restrict knee motion. Removal may be necessary.

Whatever is causing the swelling in your knee should be examined and diagnosed properly. Early recognition of problems and early intervention is usually the best way to avoid long-term or more serious complications later. See your general practitioner. He or she will refer you to a specialist if it’s warranted.

Studies show that relying on the patient’s history and a physical exam is very likely to yield the correct diagnosis. Patient’s who report swelling often have some type of internal derangement (damage inside the joint). When that’s the case, the examiner conducts a few additional clinical tests known for their reliability and validity in diagnosing problems.

Tests usually include knee range-of-motion, palpation, stability, and meniscal (knee cartilage) tests. Three special tests are often done to look for effusion (swelling). The first is palpation of the popliteal fossa (back of the knee). The second is a palpatory test called the minor effusion test. The examiner pushes the fluid in the knee from one side to the other.

And the third test of effusion is the Ballottement test. The examiner presses the patella (kneecap) down (the patient’s leg is extended or straight during the test). When there is swelling under the patella, the kneecap moves down, clicks as it touches the bone, and then floats back up.

A positive patient report (the patient thinks the knee is swollen) combined with a positive ballottement test is highly indicative of damage inside the knee. Combining results of the history and physical exam is a reliable way to assess knee effusion after a knee injury. X-rays are taken if there is suspicion of a bone fracture. Conservative (nonoperative) care is recommended otherwise. MRIs are suggested when there is doubt about the diagnosis.

Referral to an orthopedic surgeon is advised if there is clicking of the knee and/or the physician’s assistant has reason to believe there is internal derangement of the knee such as a ligament or meniscal tear.

Older athletes pose some interesting and different challenges from younger adults. Degenerative changes affecting the knee can include the ligaments, meniscus, and/or joint cartilage. Lesions or holes in the articular cartilage (lining the surface of the joint) can be repaired. But in older adults, thinning of the entire surface can present some problems. Repairing isolated defects doesn’t change the overall loss of joint surface.

Surgical treatment for cartilage damage is still controversial. Results vary (some patients have a good result while others don’t), and it’s not clear why. Perhaps it’s a matter of identifying patient factors that predict success or failure. Research is underway to help sort this all out.

Some of the techniques used include drilling holes in the articular cartilage down to the bone, abrasion of the articular cartilage, and microfracture. These marrow stimulation procedures release tiny fat and blood droplets from inside the bone marrow. The result is to create or foster a healing response.

Another approach is called autologous chondrocyte implantation (ACI). In this procedure, healthy cartilage cells are harvested or removed from the patient. They are transferred to a lab where they grow and multiply, a process called expansion. Then they are transferred back to the patient. The surgeon injects the new cells into the defect where they fill in and grow new chondrocytes (cartilage cells).

Most of the research to date on all of these procedures has been done on young athletes. The technique is fairly new, so we don’t have data to analyze long-term results. The first place to start is to see your physician. It may be that a simple program of medications and specific exercises would help enough to avoid surgery. If not, then some of the other treatment options can be considered.

Cartilage injuries in the knee can be a big problem. Healing is very slow, if it happens at all. That’s because the cartilage in the knee doesn’t have much of a blood supply. These injuries can occur as a result of trauma (usually athletic injuries) or degenerative changes associated with aging.

Surgeons and scientists have worked hard to find ways to enhance or speed up cartilage healing. Two cartilage-stimulating techniques developed in the recent past are microfracture and autologous chondrocyte implantation (ACI). Chondrocytes are cartilage cells.

Microfracture is the drilling of tiny holes in the cartilage to stimulate bleeding and a healing response. Autologous chondrocyte implantation (ACI) is the removal of normal, healthy cartilage cells from the patient. The donor tissue is either removed and expanded (grown) in the lab and then reinjected or it can be harvested from the patient and immediately reinjected directly into the damaged area.

It sounds like your brother had the implantation procedure — perhaps with less than satisfactory results. Soft, spongy fibrous tissue forming in and around the defect isn’t really all that uncommon. If the knee is stable, further treatment may not be needed. But if there are symptoms of pain, swelling, or giving way (knee buckles when standing on it or walking), then a second procedure may be needed.

The best thing to do is encourage your brother to go back to the surgeon for a reevaluation.

Your physical therapist or other sports team member guiding you can help identify a scale or scales for measuring outcomes. There are many available for assessing patients with knee injuries. Some of the more common tools include the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), specific to osteoarthritis of the lower extremity, and the Knee Injury and Osteoarthritis Outcome Score (KOOS), geared toward sports injuries.

Other knee specific (mostly focused on ligaments) include the International Knee Documentation Committee Subjective Form (IKDC), Lysholm Knee Scale, Cincinnati Knee Rating Scale, and the Anterior Cruciate Ligament Quality of Life (ACL QOL) score.

The WOMAC may not sound like it fits young, athletes, but it does include subscales on pain, stiffness, and physical function. Each of these scales measure various aspects of physical functioning, emotional well-being, pain (and other symptoms), limp, work-related concerns, and sports participation.

Sometimes specific activities such as running, cutting, decelerating, and pivoting are assessed. Just as important are measures for social functioning, emotional vitality, and quality of life. It may be helpful if you come up with a list of things you want to achieve to help gauge your own progress. Tools and scales such as these mentioned are helpful but they aren’t meant to be used at the end of each day to mark progress.

Your physical therapist will be measuring motion, strength, and flexibility. These short-term measures can be extremely helpful. At the same time, you may be self-evaluating symptoms such as pain, stiffness, and sports-related (or recreational activities) function.

The changes that are occurring in measuring the results of treatment for knee injuries are placing more of an emphasis on global (overall) assessment. Scales used can assess both recovery from the knee injury and effect of specific treatments applied. Including patient quality of life and satisfaction rounds out the results. All of these measures should be used to justify treatment selected or to modify treatment when expected results are not forthcoming.

You are quite right in your concern. In general, among health care professionals, greater recognition is being given these days to the importance of patient satisfaction. Along these lines, a shift has come with a change from clinician-based measures of results to a more patient-reported outcomes base. This has meant a modification in the tools doctors and other clinicians treating knee injuries use to measure change.

Patient-reported outcomes are certainly subjective (based on the patient’s assessment). This is a shift from the measurements clinicians have always relied upon (e.g., range of motion, strength, motor control). And it is a reflection of the fact that sometimes objective measures of strength show improvement, but the patient’s function doesn’t improve or the patient isn’t happy with the results.

If a patient improves enough to return to school or work but not enough to return to sports or recreational activities, is that good enough? And by whose standards? In other words, who sets the bar for acceptable results — the surgeon, the patient, or the health insurers?

Experts suggest that separate measures are needed for separate areas. There are multiple tools to assess outcomes — more than 50 for the knee alone, a dozen just on anterior cruciate ligament (ACL) injuries. At the very least, the clinician should use a general health survey and a second scale to measure specific results of the disease, injury, or condition.

When choosing the right assessment tool, the surgeon or other health care clinician must keep in mind several factors. Is it relevant to the patient? Is it reliable and valid? Is it easy to administer, score, and interpret? Is it responsive? In other words, can it detect a change (improvement, decline) when it occurs?

It may be helpful to match the patient’s goals with scales that provide a way to tell whether or not the goal(s) have been met. A different tool may be used with athletes who have higher expectations than an older adult who just wants to be able to walk again. Here’s where you come in. Let your team know of your dissatisfaction.

Explain your concerns and what goals you would like to meet. Ask for a better (or maybe just different) standard for measuring or assessing your progress. That should be enough to redirect your evaluation process and possibly even change the type of treatment you are receiving.

The four week time period may be just a way to follow-up quickly after a trial of rehab. If you have made enough progress to support continued therapy, you’ll know by then. But if it’s a marginal (or no) response, and you need to return-to-sports quickly to keep your scholarship, then surgery may be advised sooner than later.

It’s not that you couldn’t go to rehab for more than four weeks and still have a successful result. It’s more the fact that you are a high-activity athlete who wants to get back to your preinjury level of play as soon as possible. Waiting more than four weeks would mean missing important competitive events — and that would defeat the purpose of trying rehab for a rapid return to high-demand sports activities.

In general, anyone who qualifies for nonoperative care but who experiences any signs of knee instability (pain, swelling, buckling) should return to their physician right away. The risk of reinjury, episodes of instability, and premature knee joint degeneration is great enough to warrant early surgical intervention.

Highly active people who injure their anterior cruciate ligament (ACL) in the knee are often faced this important treatment decision: surgery or no surgery? Until now, athletes have been encouraged to put aside their immediate sports play for the opportunity to get back in the game later. Early surgery has been routinely advised for athletes who want to resume high-demand activities.

Until recently, we didn’t have a way to tell who is a good candidate for nonoperative care and who should just go ahead and have the surgery. But researchers at the University of Delaware have put together clinical guidelines using a screening exam that might just do the trick.

It’s based on more than 10 years’ worth of study, clinical trials, and careful evaluation. The athletes included were those who put in more than 50 hours each year of high-demand activities such as jumping, cutting, pivoting, or lateral movements.

Their results (72 per cent success rate) was much higher than in other studies where patients decided for themselves not to have surgery. Their work will have to be repeated by others to validate their findings. But for now, they report an increased ability to return highly active adults to their
preinjury level of activity safely and effectively without surgery.

Your surgeon is the best one to advise you on this decision. The type of injury, severity, and the presence of other injuries can make a difference. For example, a ruptured ACL along with damage to other knee ligaments or injury to the other knee, the meniscus, or joint cartilage makes the person a poor candidate for nonoperative care. Likewise, fractures, dislocations, back injuries, or nerve injuries also put the patient at increased risk for a poor result with conservative care.

If you have swelling or the knee buckles or gives way underneath you, then surgery is probably necessary before going back to sports. There are other clinical tests including a series of hopping activities that can be done to determine the stability of your knee. If you pass those tests, then you might be a good candidate for a short rehab program before getting back into the game.

Rehab should include a focus on perturbation exercises (putting the patient off balance), muscle strengthening, and cardiovascular exercise (aerobic training). Agility and coordination training along with sport-specific skills are also important. Before returning to sports participation, each athlete should pass a battery of functional tests. This is necessary to be cleared for full return to preinjury activities.

The anterior cruciate ligament (ACL) is probably the most commonly injured ligament of the knee. It is is located in the center of the knee joint where it runs from the backside of the femur (thighbone) to connect to the front of the tibia (shinbone).

The ACL is the main controller of how far forward the tibia moves under the femur. This is called anterior translation of the tibia or tibial translation. If the tibia moves too far, the ACL can rupture. The ACL is also the first ligament that becomes tight when the knee is straightened. If the knee is forced past this point, or hyperextended, the ACL can also be torn.

In most cases, the ligament is injured by people participating in athletic activity. As sports have become an increasingly important part of day-to-day life over the past few decades, the number of ACL injuries has steadily increased. This injury has received a great deal of attention from orthopedic surgeons over the past 15 years, and very successful operations to reconstruct the torn ACL have been invented.

When combined together, too much of these two motions (tibial translation and internal rotation) are what result in something called the pivot-shift phenomenon. The athlete plants his or foot on the ground and attempts to make a sudden shift or move in another direction. With an unstable knee, the joint buckles or gives way underneath the athlete.

Stability means that the ACL (working with the other intact ligaments and soft tissue structures) provides normal knee motion and prevents too much tibiofemoral translation from occurring. No one really expects grafts to restore normal motion and provide perfect check-reins on abnormal motions.
The natural, normal ligaments’ design and fiber tension behavior are simply too complex for that. But the graft can provide enough tension to protect the knee from instability and restore normal function. This can be done without limiting normal tibial motion too much, a situation called overstraining.

Over the years, surgical technique for the repair of a ruptured or deficient anterior cruciate ligament (ACL) has evolved and changed. Most recently, in the 1990s, surgeons went from using a two-incision tunnel to a one-incision technique. Results of each method have been studied and compiled.

The incisions are made to create tunnels through the bone. Graft tissue is threaded through the tunnels. Graft placement appears to be an important factor in the success of ACL repairs (single or double). The graft must be able to resist tibial translation (movement of the lower leg bone against the femur or thigh bone). It must also resist abnormal internal tibial rotation.

The repair can be done as a single bundle approach or a double-bundle procedure. Just as the term indicates, single-bundle is a piece of tendon taken from elsewhere around the knee (usually patellar tendon or hamstrings) and used to replace the deficient ACL. A double-bundle graft is more likely to be made of hamstring material. The double-bundle is formed by folding the graft over to form two layers of graft material.

The double-bundle graft was developed to provide greater stability. It was felt that a single-bundle graft led to too many failures. But the double-bundle graft is complex and requires two grafts and two femoral and tibial tunnels. There’s been some question about the failure rate for this approach compared with the single-bundle method.

It has been noted that a vertically oriented single-bundle ACL graft resulted in many more patients with too much knee instability (compared with patients who got the double-bundle graft). But there were other studies where there wasn’t much difference in results between these two procedures.

So, some authors advocated the simpler, less complex single-bundle procedure. Why go to all the trouble of using the double-bundle technique when the single-bundle works just as well and isn’t such a technically demanding operation?

In looking back at all of the studies (cadaveric and human), one method doesn’t appear superior over another. There are different advantages and disadvantages to each. It may be that the location of the graft is a key factor in results.

In some cases the orientation of a single-bundle graft can give the same stability provided by a double-bundle graft. The next step will be to conduct studies comparing locations of single-bundle grafts. The goal would be to find a single-bundle orientation that offers all of the advantages of a double-bundle approach without the complexities of technique.

The jury may still be out on this one. A recent study of young, active (male) military recruits compared arthroscopic repair with nonoperative care. They found that arthroscopic repair got the soldiers back in action faster than conservative care (bracing and exercises), but the rate of recurrent (second or third) patellar (kneecap) dislocations wasn’t any different between the two groups.

And that can be a significant factor in training for sports, marathons, or military action. So, they are back to the drawing board in terms of finding the best way to treat these types of injuries. Using measures of pain, activity levels, function, and patient satisfaction help them sort out what works best and for whom.

There are multiple factors that weigh in on the treatment decision. These include severity of injury, accompanying soft tissue damage, presence of any loose bodies inside the joint (e.g., bone fragments, pieces of cartilage or meniscus), and how recent was the injury.

Most kneecap dislocations are lateral patellar dislocation. Lateral means the kneecap moves away from the midline (toward the outside of the knee). When that happens, the structures along the medial (inside) of the knee are often torn or damaged.

In particular, the medial patellofemoral ligament (MPFL) is usually injured. Studies have shown that half the restraining force holding the kneecap in place comes from the MPFL. Successful treatment must address the condition of the MPFL. If it’s torn and is not repaired, then the chances of recurrent patellar dislocation increase dramatically.

Successful outcomes may depend on the type of surgery performed. Arthroscopic repair reduces the risk of injuring blood vessels and nerves in the knee. And any loose fragments of bone, cartilage, or meniscus can be removed easily.

But complete rupture of the MPFL at its femoral attachment may not be seen and cannot be restored fully by arthroscopic surgery alone. There may be other soft tissue injures that remain unidentified with arthroscopic repair. The surgeon relies on MRIs to help identify the location and extent of soft tissue damage.

Once you have been examined and necessary imaging studies have been done, the surgeon will be able to give you a better idea of what to expect for treatment and rehab. Be sure and let him or her know about your upcoming marathon, goals, and the time line involved. All of this information can be taken into consideration when forming the best plan of care for your situation.

Electrodiagnostic studies are tools available for testing nerve and muscle function. Nerve conduction velocity (NCV) is a measure of nerve function. This test can show how fast and how far messages are traveling along the nerve to the muscle. Electromyography (EMG) tests are a measure of electrical impulses that result in muscle contraction.

These tests can be used to find out how severe is the nerve injury and to monitor the patient’s progress during recovery. Changes in NCV and EMG don’t usually show up until about three weeks after the injury. That’s why doctors wait to order these tests. This time period is referred to as the latency period.

During those three weeks, the surgeon will continue to monitor the patient, perform neurologic tests, and look for signs of recovery. If continued, daily progress is being made, these additional electrodiagnostic tests may not even be needed. If recovery is too slow or not apparent, EMG and NCV can help determine if some other treatment is needed and/or tell a bit about the prognosis.

Testing can confirm if there has been a complete cut of the nerve. If that’s the case, then surgery is advised. Incomplete injury requires more of a watchful waiting period. Usually, with an incomplete injury, the nerve regenerates at a rate of one millimeter per day. The surgeon will measure the distance from the injured nerve to the first muscle it controls. Calculating the distance and estimated time of arrival for the nerve at that site gives some indication of when to expect motor recovery to occur.

A physical therapist can work with your daughter using electrical stimulation. This can help prevent atrophy of the muscles normally innervated by the injured nerve. The patient can take a handheld electrical stim device home for use while waiting for the nerve to heal and strength to recover.

Knee dislocations are known to cause severe ligament damage with knee joint instability. If the blood vessels and local nerves in the area are damaged, the risk of losing the leg is much higher. Such damage can occur even with a single ligament rupture in the knee. And what appears to be minor trauma (e.g., fall from standing) can also cause serious damage to the blood vessels. Without early diagnosis and treatment, loss of limb is a definite possibility.

To prevent this from happening, a careful assessment is made. The surgeon begins with a patient interview, clinical tests, and imaging studies. X-rays can help show any fractures that might be present. A neurologic exam can reveal nerve damage. A quick screen for pulses can help identify vascular (blood vessel) injury. This test should be done before and after any treatment to reduce a dislocated knee. Damage to even small blood vessels can result in local hemorrhaging and loss of vital blood supply.

Testing pulses is a very accurate clinical test. Pulses must be checked every two hours for up to 48 hours. More specific vascular studies (arterial-pressure index, Doppler ultrasound, arteriography) can be ordered if there is any sign of vascular compromise. Restoring circulation quickly (within six to eight hours) is absolutely vital in saving the leg. Most experts agree that treatment for known or suspected vascular injury should not be delayed by doing additional imaging studies.

Other injuries such as disruption of the peroneal nerve or tibial nerve may be present with knee dislocation. The force of the injury is enough to cause traction or stretching to the nerve(s). Anyone with avulsion fracture of the fibula (smaller bone in the lower leg) is at increased risk for peroneal nerve damage.

The surgeon must look for such injuries and address them in treatment. Even with treatment, the risk of sensory and motor damage is high. Difficulty walking because of a foot drop can lead to permanent disability.

With all of these injuries, the patient must be followed carefully. It can take some time before the extent of recovery can be determined. Surgery to restore blood flow involves repairing the damaged blood vessels. Once the blood supply has been restored, then the ligaments may be repaired. This may be done in the same procedure, but more often, the surgeon waits two to six weeks. This gives time for healing of the blood vessel(s). Without adequate blood supply, repairing or reconstructing the ligament won’t be successful.

You may have a condition called hamstring syndrome or proximal hamstring syndrome. Proximal just refers to the fact that the problem (and the symptoms) occur at the top of the hamstring muscle rather than down at the bottom where it inserts into the knee area.

The proximal (upper portion) hamstring muscle attaches to the ischial tuberosity. The ischial tuberosity is the part of the pelvic bone that we sit on — otherwise referred to as the sit bone. With proximal hamstring syndrome, the sciatic nerve becomes tethered or attached by adhesions or scar tissue to the hamstring muscle. There may be a specific (hamstring) injury that led to the start of this problem. Or the symptoms may have developed slowly over time creating a chronic problem of hamstring tears with scarring and eventual tethering.

But there are other possible causes of buttock pain such as piriformis syndrome, hamstring tears, or sciatica. You will need to see an orthopedic surgeon to get a definitive diagnosis. The surgeon takes a careful history and performs an exam to make the diagnosis. Usually, the pain pattern of proximal muscle syndrome is slightly different from these other conditions. There is pain in the buttock that goes down the leg toward the back of the knee. When the examiner presses on the ischial tuberosity, it reproduces the pain or is tender.

Sitting or stretching the hamstrings also brings on the painful symptoms. This pattern is different from a hamstring tear where the pain is more in the muscle belly or the piriformis syndrome where the tenderness is deep in the buttock muscles. Weakness of the hamstring muscle is also common with proximal hamstring syndrome. The athlete is unable to run at full speed — or even increase the pace in that direction.

Nerve conduction tests were not always helpful. The results are just as likely to be positive or negative in patients with proximal hamstring syndrome. A better test is performed with the patient prone (face down). Strength of the hamstring muscle is tested with the knee bent to 30 degrees and compared with the same strength test at 90 degrees. Severe weakness with the knee flexed at 30 degrees (compared with normal strength at 90 degrees) is a good test for this problem.

Once an accurate diagnosis has been made, then a plan of care can be determined. Usually, conservative (nonoperative) care is advised before considering anything more invasive such as surgery.

The hamstring syndrome was first discussed in the late 1980s. Athletes involved in many different types of sports have experienced the pain, tenderness, and weakness that occur with this syndrome. At first it was only called hamstring syndrome. But more recently, it was renamed proximal hamstring syndrome to indicate a more precise location of the problem.

Symptoms include pain in the buttock that goes down the back of the thigh to the knee with weakness of the hamstring muscle. When the examiner presses on the ischial tuberosity, it reproduces the pain or is tender.

The ischial tuberosity refers to the part of the pelvic bone that we sit on. This is where the proximal (or upper portion) of the hamstring muscle attaches to the pubic bone. Sitting or stretching the hamstrings also brings on the painful symptoms. Running, sprinting, and kicking activities are extremely difficult with this problem.

If conservative care is unable to provide pain relief and return of strength and function, then surgery may be advised. The sciatic nerve is released from the hamstring muscle where the two have become tethered or attached by adhesions or scar tissue. The sciatic nerve is carefully cut away from the hamstrings. Scar tissue and any areas of obvious tendon scarring or degeneration are removed. The surgeon is careful to avoid disturbing the nearby posterior femoral cutaneous nerve.

There aren’t very many studies reporting results of treatment for this problem. But between 75 and 80 per cent of athletes are able to get back to sports participation and are happy with the results. In a few cases, pain is not relieved. Complications such as wound infection and nerve injury can occur. This doesn’t happen very often, but the patient must be prepared for the possibility.

Rehab and recovery are fairly short. Running activities can begin four to six weeks after surgery. The athlete gradually progresses his or her training program. By 12 to 16 weeks, the player is back to full sports participation.

Age has been an issue when considering the merits of chondrocyte implantation. This type of treatment is used for cartilage defects that cause pain and loss of knee function. Studies on the use of chondrocyte implantation among older adults are very limited. This is due, in part, to the notion that by age 45 or older, the patient would do better to have a total knee replacement instead of chondrocyte implantation. Recovery is faster with fewer problems.

But newer studies comparing results in younger versus older (over 45 years old) age groups have shown similar results no matter how old the patient was. So, age may not be the key factor after all. Of course, there may be a particular age after which chondrocyte implantation just isn’t as good of a treatment approach as joint replacement. But further studies will be needed to identify just where is the cut off age for success versus failure.

Anyone (young or old) who is thinking about having chondrocyte implantation for cartilage defects should be told about possible complications. Besides graft failure, one of the most common problems is overgrowth of the implanted cells called hypertrophy.

A second challenging problem is the formation of adhesions (fibrous scar tissue). Both of these complications requires a second surgery to correct the problem. As many as one-third of all ACI patients end up having a second arthroscopic procedure. They call this a second-look arthroscopy. The excess tissue is shaved away or removed, providing long-lasting positive results.

Surgeons in Europe have solved this problem by replacing the periosteal cover used to protect the implant with a new collagen membrane. This new patch is not yet available in the United States. In the meantime, careful patient selection (young or old) remains a key factor in the success of the ACI procedure. Age does not have to be an immediate strike against the patient. Obesity, noncompliance with the rehab program, tobacco use, and loss of joint space are major risk factors for failure. Such patients must be screened for and excluded from this type of surgery.