FAQ Category: Knee

You are right that computer-guided joint replacement has recently been introduced. And as always with new and improved technology, the costs do go up.

But in this case, the cost of less invasive reconstructive surgery may be well worth it. First of all, improved implant alignment of total knee replacements are possible with computer-guided systems.

Accuracy is important because any imbalance can lead to uneven wear and tear on the implant. And that can mean more pain and loss of function for the patient. Decreased quality of life may add insult to injury.

Good implant alignment is now possible even when using smaller incisions. Less cutting on the knee translates into improved muscle and joint function.

Studies show that tiny receptors in the joint complex register position and movement. When these mechanoreceptors are damaged during surgery, recovery takes longer. Over time, anything that alters the normal biomechanics of the joint can lead to disability and even a second surgery. The cost of either is greater than the added expense of computer technology.

Improved technology and surgical equipment has made it possible for surgeons to perform some operations with smaller incisions. This is called minimally invasive surgery (MIS).

A smaller incision also means less damage to the soft tissues and muscles. In the case of knee replacement surgery, the ligaments inside the knee and the quadriceps muscle along the front of the thigh are spared during MIS.

Studies show that preserving the integrity of the soft tissues also maintains more normal knee function. Proprioception and kinematics remain normal or near normal. Proprioception refers to the joint’s sense of position. Kinematics is the actual motion of the joint.

Patients end up with a more functional knee after UKA compared with a total knee replacement (TKR) that is done with the standard, open incision approach. The UKA patients can put more weight on the leg sooner. They return to full activities faster.

Studies show these positive results are likely the result of preserving normal biomechanics and kinematics in knees after UKA implantation.

Chondroitin sulfate (CS) is one of two products purchased over-the-counter by many people with osteoarthritis (OA). The other supplement is called glucosamine. These nutraceuticals have been used alone or combined together by many arthritis sufferers.

Research and regulation of these products began in Europe over 20 years ago. The United States has been much slower to follow in its use of these supplements. There have been enough studies now to recognize some patterns with CS use.

For example, it appears that there’s a placebo response in the first few weeks using these products. That means people feel better because they think the pill is working. In the case of CS, its analgesic (pain relieving) effects are slow to kick in. It takes two to three months before getting maximal pain relief from this product.

There’s some evidence that CS works better when it’s combined with glucosamine. And these products seem to have their best effect in patients who have moderate to severe OA pain.

Patients with early stage OA may not see the benefit in pain relief or improved function. It’s possible these nutraceuticals help slow or even stop the progression of OA. This hasn’t been proven yet. If it’s true, then taking CS and/or glucosamine at the first sign of OA might be recommended.

Minimally invasive surgery (MIS) has become more and more popular with patients and surgeons. Besides the obvious improvement in the scar, there are other benefits as well.

Smaller surgical tools are used in MIS. The surgeon is guided by a computerized navigational system. It isn’t necessary to cut through so much of the soft tissues. This means recovery is generally faster. Patients regain full function sooner than with the standard open incision method.

The operating time is usually longer using the navigation system compared to the conventional manual method. But the added amount of time is small — only an extra 10 minutes of time is added on.

And experts agree that the extra time is worth it when it comes to the added information the navigational system provides. The surgeon can use this data to choose the best implant for you and make the necessary anatomical adjustments during the operation.

For many years, studies reported that surgery to repair or reconstruct the damaged structures of the knee could protect the joint. The positive role of surgery for anterior cruciate ligament (ACL) repair and meniscus tears was strongly suggested.

Taking a closer look now shows a lack of evidence that surgery has a protective role in these patients. When researchers tried to pool or combine the data from many studies on the topic, they found poor reporting of important variables. Without quality research and reporting, the data can’t be compared from one study to another.

Even with improved surgical methods, outcomes in more recent patient reports don’t appear to be any better. If anything, improved technology has made it possible to show arthritic changes as they develop earlier in the process than ever before.

Surgical treatment may benefit some patients. But for now, there is a lack of convincing evidence to support our previous belief that surgery is needed to avoid the later development of osteoarthritis.

It’s possible there are other risk factors and events that affect the outcome more than surgery. Finding out what these are is the focus of current research.

For patients who have cartilage defects, there are a few ways to treat it. One procedure, called a autologous chondrocyte implantation involves two steps. First, the doctor will use a special needle to remove some cells from the cartilage in your knee. When the cells are removed, they are grown in a laboratory and regenerated. Once they are ready, the cells are reimplanted into your knee, which is the second procedure.

One of the most common fractures that can happen to complicate a knee replacement is a fracture in the femur, or thigh bone. Many patients who have such a fracture don’t have any pain or experience any problems with their knee. In fact, often the fracture is only found by the doctor during a routine check up and x-rays.

If your father’s fracture isn’t causing any pain or discomfort and the knee is working well, the doctor takes that into consideration when deciding on treatment. As well, when the fracture is found on the x-ray, it is possible that it has already healed and it is an older fracture that the doctor saw. In this case, there is no reason to perform any repairs.

After a knee replacement, the femur, or thigh bone, can be fractured, either due to a trauma like a fall, or just from stress from the bone and the replacement. This does not happen often, but it does happen.

Researchers have found that of the people with these fractures, more patients had had revisions than first time surgery. Therefore, having had a revision, you do have a higher risk of a fracture.

The unicompartmental knee arthroplasty (UKA) has several advantages over a total knee replacement (TKR). As you mentioned, it is an acceptable alternative to TKR when only one side of the joint needs to be replaced.

UKA is less invasive and removes less bone compared to a TKR. Improved computer-assisted surgical methods and improved implant quality have made it possible for younger patients to benefit from the UKA.

The exact definition of younger has not been statistically determined. Each patient is evaluated by the orthopedic surgeon for this type of implant. Studies report surgeons are using the UKA in adults ages 47 to 83.

Older age is not as much of a challenge as younger age. The reason for this is concern over how many years of wear and tear the implant can handle. The average TKR lasts about 15 years. Older adults who have a TKR usually die before the knee wears out. The average life of the UKA is unknown. Mid- and long-term results of UKA are slowly trickling into the published literature.

Patients with UKA report their motion and feeling with the implant are more like a normal joint. Computer analysis shows knee joint biomechanics with a UKA are closer to a normal knee compared to the biomechanics provided by a TKR. That’s because the cruciate ligaments inside the joint are not cut or removed with a UKA (but they often are with a TKR).

At age 62, you may be a good candidate for a UKA. With increasing life expectancy for many adults, the UKA may give you added years of quality knee function. Then if you need to convert to a TKR later, it may be an available option.

By a partial knee replacement, we assume you are referring to a unilateral knee arthroplasty (UKA). This is the placement of an implant on either the medial or lateral side of the joint. Medial refers to the side closest to the other knee. Lateral is the out side half of the joint.

UKA is a good choice for active, younger adults who don’t need a total joint replacement but who have painful symptoms that limit their activity.

Staying active while preserving the implant is a challenge. Sports participation is important to many patients who have a UKA. but finding the right level of activity that avoids implant wear or loosening is important.

Orthopedic surgeons and sports experts suggest the following guidelines for patients with a UKA:

An orthopedic surgeon can help diagnose the problem. History, exam, and imaging studies are the key tools used. Ultrasound can be used to assess tendon thickness and structure. Any irregular areas will also show up.

The results of this evaluation may point to the need to conduct further tests. A biopsy to examine the tissue in question under a microscope may be done.

The pain you described suggest your symptoms are made worse by movements and activity that loads the Achilles’ tendon. This is common with a condition known as tendinopathy. Although you didn’t mention your age, many middle-aged recreational athletes are affected by Achilles’ tendinopathy.

Acute injury leading to an injury of the anterior cruciate ligament (ACL) are usually traumatic with a lot of force behind them. In fact, ACL tears alone are uncommon.

Most athletes or active adults who rupture the ACL also suffer other injuries at the same time. There may be other ligament sprains, tears of the mensiscus, and injuries to the joint cartilage. Bone bruises and bone fractures are less common but sometimes do occur.

A bone bruise is also known as a post-traumatic bone marrow lesion. The force of the trauma is great enough to actually leave its mark called a footprint on the bone. Evidence of a bone bruise is found on MRIs.

There’s evidence that even if the cartilage doesn’t appear damaged, when a bone bruise is seen, it’s likely that the impact was enough to injure the joint cartilage, too.

Biologically, a bone bruise means the cells of the bone marrow are affected. There may be a disruption in their metabolic rate and function. Some cells may even die or die sooner than they would have if no injury had occurred.

Wear and tear on the plastic tibial Uneven wear patterns are not something a patient can avoid. Sometimes imbalance in the joint or soft tissue alignment cause the uneven wear pattern.

The asymmetrical pattern can affect different parts of the implant at the same time. This could include the front, back, and/or sides of the joint surface.

There may be scratches or wear patterns all the way through the implant. It sounds like this is what has happened to yours. Once your surgeon removes the insert, an examination of the wear pattern may help show what is the problem.

Location, type, and depth of wear pattern will be observed. This kind of information is helpful for surgeons and scientitsts who are trying to improve TKR implant design and results.

Shelf life of prostheses (implants) for joint replacement is important. But it may not be as important as two other factors. The first is whether or not the implant has been sterilized properly.

Studies show that sterilization using the gamma radiation-in-air method may be linked with preserving the thickness of the insert. Polyethylene (plastic) tibial bearings also hold up better with a second type of sterilization (nonradiation method).

The second factor is implant design. Too long of a shelf life may mean using outdated implant designs. With ongoing research, scientists have been able to find ways to improve the design.

You surgeon will double check the type of implant and match it to your specific joint and activity needs. It doesn’t hurt to ask your surgeon more about the details of the implant selected for you.

The only person who can tell you if exercising your knee would be a good idea is your own doctor. So much depends on the type of injury you had, the type of surgery you had and the wear and tear that your knee has undergone since the surgery.

That being said, there are general knee exercises that can be done with healthy knees and on problem knees if your doctor has given the ok. They include:

Maintaining a good range of motion by using the knee regularly, keeping it moving naturally

Keeping your leg muscles strong and protecting the knee by walking, climbing stairs, or doing exercises that strengthen the leg muscles.

Before doing any type of exercise that may put stress on your knee, please speak with your doctor.

If the tear in the cartilage is not large and if you are not an athlete or are doing some sort of work that puts a lot of stress on your knee, your doctor may very well recommend conservative therapy, perhaps using a brace, and letting the cartilage heal on its own. When your knee can handle it, you may be given exercises to help build up the muscle in your leg to help protect your knee.

However, for larger tears or if you are very active, surgery may be the solution.

This cocktail injection is the latest development in pain control after total knee replacement (TKR). Up until now, patient-controlled analgesia (PCA) has been the latest break through.

PCA allows the patient to push a button and release a small amount of narcotic (pain killer) into the blood stream. It’s set up on a timer so the person can’t take too much. PCA has allowed for better pain control and improved rehab.

The cocktail you are referring to is a combination of several drugs. This includes a numbing agent called Marcaine. It’s very similar to Novocaine. The cocktail also includes an antibiotic, steroid, and morphine (a narcotic drug).

The cocktail is injected in two parts. The first injection goes into the joint capsule before putting the new joint liner in place. The second injection goes into the periarticular (around the joint) soft tissues after the knee implant is in place. The synovium, muscles, and ligaments are injected.

According to the early results, this periarticular cocktail injection speeds up recovery. Patients are able to perform a straight leg raise sooner than when using the PCA. More patients go home sooner after the cocktail method of pain control.

If you did well with the PCA approach, it’s likely you’ll do even better with this new method.

It’s true that operative techniques, surgical methods, and even the implants themselves have changed quite a bit in the last three decades. Improvements in all these areas has shortened the hospital stay and reduced the rehab time.

There is less blood loss during the operation. Long-term complications are fewer as well. But pain control is still an issue. Managing pain during the first few days and weeks post-operatively can be a challenge.

Right now it looks like we might be moving away from patient-controlled analgesia (PCA). PCA allows the patient to administer a small dose of narcotic drug as the last dose starts to wear off. Keeping control of the pain level helps improve recovery.

Efforts are being made to provide the same or better pain control while improving function and recovery. Injecting a combination of drugs into the surgical site before and after the implant is inserted may be the next step.

A study comparing results using PCA versus this new cocktail injection has been reported. The outcomes are very favorable. Patients receiving the injection were able to perform straight leg raises faster and better than the PCA group. Hospital and recovery time was shorter with fewer problems.

The next generation may not even need joint replacements. Gene transfers and cartilage tranplants may make it possible to heal joint damage. If they do need an implant, minimally invasive surgery will be combined with improved post-operative management. This should mean a faster, easier procedure.

There are some alternative ways to control pain that don’t involve any medications. Acupuncture, hypnosis, and electrical stimulation are three of the more commonly used non-drug ways to manage pain. Sometimes they are used together.

There are also other ways to control or manage your pain using medications. A new pain control method is called the periarticular cocktail injection. Periarticular refers to anything near or around the joint. Cocktail describes a mixture of medications combined together.

These drugs are injected into the joint space after the old bone is removed but before the implant is put in place. A second injection is done into the soft tissues around the joint after the implant is inserted.

The results of the first study suggest this may help improve function faster. And for those who can only tolerate a small amount of narcotic, it contains an antibiotic, antiinflammatory, and numbing agent. Results after three months of follow-up are just as good as for patients receiving the more standard drugs.

It’s important that you discuss this problem with your surgeon. Reducing and controlling pain and other problems after surgery is as important as the operation itself.

Genetics may very well be a part of developing either osteoporosis (brittle bones) or osteoarthritis (OA). And there may be a link between osteoporosis and OA. It isn’t clear yet if there is a genetic link here.

The relationship between OA and osteoporosis may surprise you. Some studies show that women with low bone mass from osteoporosis may be less likely to have OA. But once OA is found, a higher bone mass density (no osteoporosis) means a milder case of OA. Just what all this means and what the actual connections are between OA and osteoporosis remains unclear.

One important risk factor for knee OA (such as your mother had) is a previous knee injury. Men and women are both more likely to develop knee OA after an anterior cruciate ligament (ACL) tear. And women are twice as likely to develop an ACL injury compared with men.

All in all, it looks like osteoporosis may have a protective effect. It may actually prevent OA from developing. Scientists are studying this phenomenon carefully. It’s possible they may discover something that could help prevent either or both of these conditions.