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Blood supply to every organ and tissue in the body is very vital for optimal functioning. Loss of blood supply to any body part or organ leads to a gradual death (necrosis) of that part or organ and can be very dangerous. Loss of blood supply to the brain results in stroke; loss of blood supply to the heart results in a heart attack; loss of blood supply to a bone tissue leads to bone death (osteonecrosis).

Knee osteonecrosis means knee bone death. It occurs mostly in older people, with women being more affected than men. Three types of osteonecrosis affect the knee: spontaneous osteonecrosis of the knee (SONK), secondary, and post-arthroscopic.

Read Also: PRP Is No More Effective for Knee Osteoarthritis than Placebo

Anatomy of the knee

The knee is one of the two major hinge joints in the body, with the elbow being the other. It is responsible for movement and very vital for weight-bearing. The joint at the knee is the largest and most complex joint in the body. It is made up of three bones the lower end of the femur (thigh bone), the upper end of the tibia (shin bone), and the patella (kneecap). Knee osteonecrosis commonly occurs in the medial femoral condyle (inside of the knee), however, the lateral femoral epicondyle (outside of the knee) or tibial plateau (the flat top of the tibia) may also be likely areas of occurrence.

The knee is vulnerable to injury; according to the database from the National Institutes of Health, it is the most commonly injured joint by adolescent athletes. Among older people, it is prone to knee osteonecrosis, which if not given medical attention early, can progress to osteoarthritis.

Epidemiology

The most common form of knee osteonecrosis is spontaneous osteonecrosis of the knee, SONK. It is mostly observed in people who are over age 50. On the other hand, secondary osteonecrosis has been observed to be more common in the younger population and it is linked to some medical conditions like sickle cell disease (SCD), consumption of alcohol, corticosteroids, and tobacco, and myeloproliferative disorders. The last form, post-arthroscopic osteonecrosis, is a rare type. Reports show that it affected 4% of patients who had arthroscopic knee surgery, particularly meniscectomy.

Causes of knee osteonecrosis

When there is a lack of blood supply to bone tissues, it leads to the death of bone cells, which results in an eventual collapse of the bone. This is the case in osteonecrosis. Knee osteonecrosis can result in a collapse of the articular cartilage covering the bone ends, and this can lead to arthritis.

Read Also: TOKA a New Customized 3D-Printed Plate for the Treatment of Knee Osteoarthritis

Risk factors

The cause of the lack of blood supply is still unknown, but studies have linked the following risk factors to the development of knee osteonecrosis:

1. Knee injury

Aside from pain and swelling, knee injuries like dislocation or fracture can also result in damaged blood vessels. Dislocation involves bone ends; fracture involves any bone part; either way, both injuries can affect the blood vessels supplying the bone, thereby, reducing the flow of blood to the dislocated/fractured bone. This is why immediate medical attention is needed. Sometimes, an x-ray or MRI scan may be done to have a deeper view of the bone.

2. Oral corticosteroid medications

It is not exactly known why oral steroid medications cause osteonecrosis, but research shows that there is a connection between them. This is disturbing because many diseases such as asthma and rheumatoid arthritis are treated with these medications.

3. Medical conditions

Some medical conditions such as obesity, SCD, and lupus are associated with the secondary form of knee osteonecrosis. HIV patients are also diagnosed with it this is because the medications for HIV treatment are also linked to the disease.

4. Excessive consumption of alcohol

Alcohol causes weight gain because it stops the body from burning fat. Drinking too much alcohol increases the buildup of fat in the body, and this can consequently lead to deposits of fat tissues that can block blood vessels and obstruct blood flow to the vessels.

5. Transplants

Studies show that osteonecrosis can occur after organ transplants, especially kidney transplants.

Read Also: Duke University Researchers Create a Gel That Could Replace the Cartilage in the Knees

Symptoms of knee osteonecrosis

The most common symptom associated with osteonecrosis of the knee is pain on the inside of the knee. The pain can be triggered by a specific activity or a minor injury and can become intense at night.

Other symptoms include: swelling over the front and inside of the knee, increased sensitivity to touch in the area, and limited movement of the knee due to pain.

Diagnosis of knee osteonecrosis

A good diagnosis of knee osteonecrosis begins with a thorough history taking.

Here, your doctor will talk about your medical history, ask you to describe your symptoms and then proceed to examine your knee.

While examining your knee, your doctor looks out for swelling within your joints, tenderness, redness, and joint instability.

You may be asked to move your knee to observe the range of motion at your knee joint.

Your doctor also looks out for any sign of injury to the muscles, ligaments, and tendons around your knee.

After a physical examination of your knee, your doctor then goes on to confirm the diagnosis by taking an imaging study of your knee either with an X-ray study, magnetic resonance imaging (MRI) scan, or a bone scan. An imaging study is vital as it helps to take a deeper look at your bones and other aspects of your knee joint to identify the stage of knee osteonecrosis you have.

Read Also: Still No Effective Cures for Osteoarthritis but There Is Some Hope

Staging of knee osteonecrosis

There are four stages to knee osteonecrosis development:

Stage I: At this stage, the patient experiences symptoms that become intense and last for six to eight weeks. To be sure of the diagnosis, the doctor uses a positive bone scan, not just x-rays to get a better view of the knee. At this point, surgery is not required for treatment, instead, the doctor administers medication for pain relief and other methods that focuses on reduced weight-bearing.

Stage II: From Stage I to this stage takes several months. At this stage, x-rays can confirm the diagnosis, because the medial femoral condyle which is normally rounded now becomes flattened and can be visible with x-rays. Other forms of imaging studies such as MRI, CT, or bone scan can also confirm the diagnosis.

Stage III: From Stage I to this stage takes about three to six months, x-rays alone can confirm the diagnosis. The articular cartilage that covers the bones starts to come off the bone since the bone itself is gradually dying. Surgical procedures may be required to treat the patient at this point.

Stage IV: At this stage, the disease becomes very critical as the articular cartilage is now destroyed and the joint space becomes narrow; severe osteoarthritis develops; joint replacement surgery becomes necessary.

Prognosis of knee osteonecrosis

When knee osteonecrosis is diagnosed early (at stage I), a simple pain relief medication may be all that is needed to treat it. The doctor may also advise lower mobility of the affected knee. At advanced stages, surgery may be done to prevent increased damage to the whole joint.

Treatment of knee osteonecrosis

The treatment option for knee osteonecrosis depends on some factors which include the stage of the disease, the portion of bone that is affected, and the cause of the disease. Based on these factors, treatment can be non-surgical or surgical.

Read Also: Scientists Repair Bones Successfully by Combining Gene Therapy and Bioprinting

Non-surgical treatment option

If the disease is at an early stage and only a small area of the knee is affected, surgery may not be necessary. The doctor may suggest any of the following non-surgical treatment procedures:

1. Use of medications:

The doctor may prescribe some nonsteroidal inflammatory drugs (NSAIDs) like ibuprofen and naproxen to relieve the pain and swelling in the knee. If the patient is a young person, the doctor may suggest bisphosphonates for treatment.

2. Reduced weight bearing:

For some patients, just simply taking weight off their knees may be all that is needed to slow the damage and allow for healing. The patient may need to start using crutches for some time to reduce the weight on their knees.

3. Exercise:

The patient may be asked to engage in certain physical activities that aid in strengthening the thigh muscles and allow for a range of movement in the affected joint. To avoid stress on the joint, water exercise may also be recommended for the patient.

4. Modification in certain activities:

The doctor may advise the patient to stop certain activities that lead to pain.

Surgical treatment options

Your doctor may recommend surgery if there seems to be no improvement after the non-surgical treatment options, or if the portion of the bone affected is quite large. Some surgical procedures that may be recommended include:

1. Total knee replacement:

Your doctor may opt for this procedure if the disease has progressed to stage IV, where the bone has been destroyed. The procedure involves a replacement of the destroyed bones and cartilages with metal or plastic joint surfaces to restore the knee function.

2. Osteotomy:

In this procedure, the surgeon removes a portion of either the tibia or femur or will insert a wedge of bone graft/synthetic bone to help take the weight off the damaged portion of the knee. This is vital because taking weight off the affected area of the joint will relieve the patient of pain and promote healing.

Other surgical procedures your doctor may recommend osteochondral bone (bone and cartilage) grafting, core compression, arthroscopic debridement and microfracture, and autologous chondrocyte implantation (ACI).

Read Also: Inflammatory Joint Diseases: Actions and Foods You Should Consider to Relieve Joints Inflammation Naturally

Conclusion

As much as knee osteonecrosis is likely to occur in people who are over age 50, it can be avoided and effectively treated when we are armed with the knowledge of what it is and how to diagnose and easily manage it.

References

https://orthoinfo.aaos.org/en/diseases–conditions/osteonecrosis-of-the-knee

https://www.sciencedirect.com/science/article/pii/S2665913121000327

Medical device company Exactech has recalled hundreds of thousands of joint implants due to concerns that their polyethylene liners could degrade early and cause health complications. The first Exactech recall occurred in August 2021 and only included certain implants, but the manufacturer later expanded and recalled all ankle and knee implants produced after 2004. 

Joint replacement surgery is one of the most common procedures in the U.S., with more than a million surgeries performed yearly. During the surgery, an orthopedic surgeon removes damaged cartilage and bone and replaces them with a prosthetic piece made of metal, plastic, or ceramic. For people with arthritis and joint injuries, the procedure reduces pain and dramatically improves their quality of life. When a joint implant is recalled, these patients wonder whether they’ll be negatively affected.

The success rate for joint replacement surgery varies. Patients often need revision surgery within 10 to 20 years of the procedure, and the follow-up procedure is more complicated and has more risks than the original surgery. The manufacturer found that the Exactech joint replacement parts degraded quickly because of a packaging issue. The device’s polyethylene liners were exposed to too much oxygen, making revision surgery necessary much earlier than expected. 

Decreased joint function, pain, and swelling are telltale signs of joint implant failure. Not every Exactech recalled implant requires a second joint replacement surgery, but if it does, it can take several hours and require more specialized care. It has complications and risks like pulmonary embolisms, nerve damage, infection, and ossification.

Companies must notify consumers about medical implant device recalls, but customers might miss those advisories for various reasons — a change in address, a delay in a notification from the manufacturer, or not understanding that the recall might include their product or device. If you have an Exactech implant and haven’t had any complications, doctors don’t recommend getting it removed preemptively. But it’s still important to know whether you’re potentially affected by the recall, especially if you develop health problems. If you’re wondering whether your Exactech hip, knee, or ankle replacement implant is included in the recall, there are a few ways to find out.

Visit The Exactech Recall Website

First, you should gather details about your joint implant. Your medical records will include the precise implant you received along with the device’s serial number. You can then cross-reference this information on Exactech’s website, which has a comprehensive list of all the implants included in the recall. The searchable database consists of the product line, specific brand name, and the number of units affected. The company also has a telephone hotline for patients with questions about the recall. You’ll have the option to file a claim with Exactech for any out-of-pocket expenses caused by implant damage. However, it’s important to know that filing an Exactech lawsuit is a viable option and can lead to more compensation than settling with the company upfront.

Talk To Your Orthopedic Surgeon About Your Exactech Implant

The surgeon who operated will be able to answer questions about your Exactech implant and whether you should be concerned. Doctors must note an implant’s manufacturer, lot number, and serial number before using it during surgery. Even if your physician is no longer practicing or you’re no longer a patient of theirs, your medical records should be on file. If you do find out you have a recalled Exactech implant, telling your orthopedic surgeon is necessary. They’ll help you determine what warning signs you should look out for that may indicate joint implant failure.

Consult the FDA Database for Exatcech Implant Recalls

The FDA monitors the situation when a product is discovered to be defective. A company has the option to recall a product voluntarily, as Exactech did. If the manufacturer refuses, the FDA can force a recall. The administration has a Medical Device Recalls Database that includes detailed information about Exactech products, including serial numbers and the reasons given by the company for each recall. The government acts as an unbiased third-party source for consumers who want information about product recalls.

If you have an Exactech implant and are affected by product recalls, it’s essential to talk to an attorney before accepting any settlement offer from the company. Joint implant failure is a serious issue that can affect your earning potential and overall quality of life and cause needless pain and suffering. A lawyer will be able to help you explore your legal options and determine the best route to get the compensation you need.

While most osteoarthritis patients welcome the pain relief that comes with total knee replacement, some also experience psychological impacts that aren’t so pleasant.

“My leg feels like it’s made of lead,” one patient told a research group led by Andrew Moore, BSc, PhD, of the University of Bristol in England.

“It feels like someone is holding your knees, when you move, it’s like someone is … putting pressure there,” said another. And, said a third: “I know it’s not my knee. It’s an alien knee in there. I don’t really feel connected to it.”

Those were just some of the reactions Moore and colleagues elicited for a study now published in Arthritis Care & Research, meant to explore patients’ thoughts about their artificial implants. They interviewed 34 patients undergoing total knee replacement at two British referral hospitals, asking a semi-structured series of questions about pain and, importantly, other types of discomfort.

The researchers’ goal was to fill what they saw as a major gap in the literature on joint replacement: why some patients say they’re unhappy with the outcome despite reporting less pain and better function.

“Typically, the assessment of patient-reported outcomes after joint replacement focuses on functional outcome and pain relief as the main determinant of satisfaction,” Moore and colleagues explained. “This narrow perspective is compounded by poor definitions of satisfaction after surgery, and there is little research on how and why some patients express dissatisfaction with joint replacement and what they are dissatisfied about.”

Citing a study of hand surgery patients in which patients “spoke about their hand as if it were an object separate from their self,” Moore and colleagues argued that a psychological concept called embodiment could help explain the dissonance.

“Embodiment refers to the experience of the body as both subject and object, such that this idea impacts the way in which a person sees and interacts with the world, and vice versa,” the group wrote. “Embodiment provides a way of understanding how one experiences limits of possible action, a sense of control, and empowerment over physical action.”

Moore and colleagues hadn’t planned to look specifically at embodiment, but, they explained, “by the third interview we noted that some participants described sensations of discomfort such as heaviness or numbness when discussing pain and some described their knee as ‘alien,’ ‘foreign,’ or ‘not part of’ themselves. In response to these findings, the interviewer sought to elicit views about any such sensations in subsequent interviews, if this topic was not broached first by the participant.”

Their study emerged from an earlier one focusing on reasons for avoiding healthcare encounters post-surgery and involved the same participants: patients undergoing total knee replacement at least 1 year and as much as 5 years previously for whom initial screening indicated some degree of lingering pain or discomfort. The semi-structured interview dealt with pain (duration, timing, and other characteristics) as well as how patients managed it. After that third interview, patients who reported feelings of alienation from their implant were asked about it in more detail.

Participants were generally typical of the general knee-replacement population — mostly in their 60 and 70s, and just over half were women. Of the 34 patients, 24 were between 2 and 4 years out from their surgery.

Physical types of non-pain discomfort were commonly reported. These included feelings of numbness and/or heaviness, as well as sensations of pressure applied externally. One man said it felt like the skin over his knee was very tight. Separate from these sensations were reports that the limb no longer felt like a part of them but something foreign like an external prosthesis. Some patients complained that they weren’t always able to control the knee. “That knee just wouldn’t do what it’s told to do,” one told the interviewer.

In a similar vein, another participant said, “If I was to walk across there now and…because [of the dog] on the floor, whereas any normal person would walk along and step over him, I have to stop and think about stepping over him. My knee won’t let me do that.”

Others said they hadn’t regained trust that the knee would work properly. One man said he continues to use a cane, which by normal criteria he shouldn’t need, because of an overwhelming fear of falling.

Overall, according to Moore and colleagues, the reports were very similar to those from amputees discussing their prosthetic limbs. One reason for these reactions may have to do with patients’ lives before the joint replacement, which was often dominated by years of mounting pain and loss of functional ability.

“Presurgical chronic pain, instability, and untrustworthiness might continue to influence [mental] incorporation of the prosthesis afterwards,” the researchers suggested.

And there is a potential clinical implication for the findings: “Our study suggests that the interest for rehabilitation becomes not only strengthening the joint and promoting full recovery to tasks, but also modifying a person’s relationship with the new joint to achieve full incorporation or re-embodiment.”

Programs developed for other conditions, including use of external prosthesis as well as complex regional pain syndromes, may be helpful in this regard, Moore and colleagues offered.

“Our focus should not be on the absence or loss of embodiment,” the researchers added, “but on employing a multidisciplinary approach to using the concept to guide the development of pre-rehabilitative strategies and appropriate outcome measures.”

Depending on what you do for a living, it’s very likely that your job is highly stressful. Your entire day could be spent performing repetitive motions such as lifting heavy objects or moving around. It’s essential to take care of your body’s muscles, joints, and nerves before things get worse.

An orthopedic surgeon specializes in the health of the musculoskeletal system and can help you figure out what’s wrong and how to fix it. For those who aren’t familiar with orthopedists, here are a few things to keep in mind when deciding whether or not to see one:

Having Difficulty Climbing the Stairs 

Joints in the knees and hips naturally begin to deteriorate with age, which typically makes it too uncomfortable for the affected body parts to continue functioning normally. If you have trouble walking, climbing stairs, or getting out of chairs, it may be time for your doctor to propose that you have joint surgery. 

Joint injury can manifest itself in various ways, one of which is chronic pain that lasts for more than six months and disrupts daily life. A joint replacement may be necessary for a variety of reasons, including accidents that may have occurred in the past and years of heavy use. 

Instability Of Joints. 

Destabilization is merely one more compelling argument in favor of seeking the counsel and expertise of an orthopedic physician. Should people who have trouble standing, walking, or moving easily investigate the possibility that they have orthopedic problems? Many of them do. The easiest method to go about doing this is to seek the advice of a specialist who is already working in the sector. 

Having a Hard Time with Chores. 

The capacity to carry out daily activities without the assistance of another person is referred to as self-sufficiency. To accomplish this, you must be able to get out of bed with only minimal assistance, dress, bend over to tie your shoes, prepare your meals, and so on. 

Consult AOA Orthopedic Specialists if you are unable to execute the tasks at hand without experiencing significant discomfort or if the manner in which you are expected to carry them out is undergoing significant change. 

Disturbances in Bowel Movement and Bladder Function 

If you find yourself rushing to the bathroom or sitting on the toilet for hours at a time, which is neither pleasant nor normal, it may be time to consult a doctor. Both irritable bowel syndrome (also known as IBS) and nerve injury can have adverse effects on the intestines, the bladder, and the back. 

Irritable bowel syndrome (IBS) can cause abdominal cramping and extreme stool, both of which are indicators that your bowel system isn’t functioning correctly. This can lead to problems in the lower back. On the other hand, injury to the nerves in the back can lead to discomfort in the abdomen and make digestion difficult. 

Bottom Line

You put yourself in jeopardy of long-term damage and impairment if you ignore what your body is trying to tell you. There are several warning signs that should prompt a person to seek medical attention, particularly from an orthopedic specialist. These warning signs include problems with the joints and bones.

FOSTER CITY, Calif., April 8, 2022 /PRNewswire/ — OrthoTrophix, Inc., a privately held biopharmaceutical company, announced today that the Company and its collaborators present clinical data strongly supporting joint bone shape change as part of a surrogate marker predictive of joint replacement in knee osteoarthritis (OA) patients.

An abstract entitled, “Improved WOMAC Physical Function is Associated with Slowed Pathological Bone Shape Change after TPX-100: Towards a Surrogate Marker for Virtual Knee Replacement?” was presented today in a Plenary Session of 2022 OARSI World Congress on Osteoarthritis in Berlin, Germany (Abstract 26 in Osteoarthritis and Cartilage Vol. 30 Suppl. S28–S29).

Functional impairment is a key risk factor for knee replacement even after adjusting for knee pain severity, based on the large NIH-sponsored Multicenter Osteoarthritis Study (the “MOST” study) involving over 5,500 knees. In the TPX-100-5, a Phase 2 study, placebo-treated knees with more advanced pathological joint bone shape change at baseline showed much faster progression of pathological bone shape change and poorer knee function at the end of the 12-month study period. In marked contrast, TPX-100-treated knees demonstrated reduction in pathological bone shape change and robust improvement of knee function through 12 months, regardless of severity at baseline. Consequently, both clinical (knee function) and structural (bone shape) efficacies of TPX-100 as compared to placebo were confirmed including in subjects with moderate to severe knee OA.

“The current FDA draft guidance indicates that a positive effect on an imaging marker of OA must be associated with avoidance or delay of the need for joint replacement, or must persuasively reduce deterioration of function and worsening of pain. This is a high bar,” commented Dr. Dawn McGuire, OrthoTrophix’ Chief Medical Officer. “However, the Multicenter Osteoarthritis Study findings and our clinical data collectively suggest that concordant improvements of bone shape change and clinical function could lead to a delay or elimination of the need for joint replacement surgery. These combined outcomes in structure and function could provide a ‘virtual joint replacement’ measure for the study of disease-modifying agents in individuals afflicted with knee OA.”

The Company also will present an abstract entitled, “Intra Articular TPX-100 Significantly Improves Pain Measures and Slows Pathological Bone Shape Chage in Knee OA”. This presentation demonstrates clinically meaningful improvements in overall knee pain and in specific key pain parameters in moderate to severe knee OA, linked to significant reductions in pathological bone shape change (Abstract 254 in Osteoarthritis and Cartilage Vol. 30 S193).

About OrthoTrophix, Inc.
OrthoTrophix, Inc., based in the San Francisco Bay Area, California, is a privately held biopharmaceutical company focused on development and commercialization of a first-in-class Disease Modifying Osteoarthritis Drug (DMOAD). Founded by three co-founders in 2011, the primary focus of OrthoTrophix has been regeneration and repair of cartilage and underlying bones in the knee and other joints with its novel proprietary compounds.

This press release contains “forward-looking” statements. These statements involve risks and uncertainties, which may cause results to differ materially from those set forth in the statements. The forward-looking statements include statements regarding product development and cannot be guaranteed. OrthoTrophix undertakes no obligation to publicly update any forward-looking statement, whether as a result of new information, future events, or otherwise. Forward-looking statements in this press release should be evaluated together with the many uncertainties that affect OrthoTrophix’ business.

Company Contact
Yoshi Kumagai
President and CEO
Tel: (510) 488-3824

SOURCE OrthoTrophix, Inc.

Bi-unicompartmental knee arthroplasty (BiUKA) is an alternative to total knee arthroplasty for selected patients. Although it is thought to be technically demanding, the technique has not been previously described in detail. Kinematic alignment (KA) implantation and bone cuts parallel to the native joint line would be beneficial to ensure optimal mechanical loading. Here, we detail a technique for KA-BiUKA using the Oxford partial knees. The joint line is identified using the spoon of the microplasty instrumentation system with/without the accessory spoons. The tibia is cut parallel with the joint line using a side-slidable ankle yoke so that the inclination of the cutting block is parallel with the spoon surface. After defining the horizontal bone-cutting lines, the predominantly affected condyle is operated upon, followed by the lesser affected condyle. Although custom-made devices are required, the technique is useful and reproducible in the performance of KA-BiUKA with the Oxford partial knees.

Introduction

Technical Report

Discussion

Conclusions