Pyarthrosis - Know the Causes and Treatment

Introduction

The term pyarthrosis may also be known as septic arthritis (SA). It describes an invasion of joint cavities by various microorganisms, most commonly bacteria. Various types of viruses, mycobacteria, and fungi can also be involved. This discussion will focus primarily on bacterial pathogens. Despite the initiation of treatment, septic arthritis still sometimes leads to significant morbidity and mortality.

What Is Pyarthrosis?

Pyarthrosis is an infection of the joint fluid (synovial fluid) and joint tissue. It occurs more commonly in children than in adults. Infection usually reaches the joints through the bloodstream. Joints can sometimes become infected from injections, surgery, or injuries. Infected joints may lead to pus buildup. Infants and the elderly are most likely to develop pyarthrosis. People with artificial joints are also at an elevated risk of developing pyarthrosis. Although the knees are most commonly affected, septic arthritis can also affect hips, shoulders, and other joints. Infections can rapidly and severely damage the cartilage and bone within the joint, so prompt treatment is critical.

What Are the Causes of Pyarthrosis?

Various types of bacteria, viruses, and fungi can infect joints. Types that can cause septic arthritis include:

• Staphylococci - These are common bacteria that often cause skin infections.

• Hemophilus Influenzae - These are bacteria that infect the larynx, trachea, and bronchi.

• Gram-Negative Bacilli - A group of bacteria that includes E. coli.

• Streptococcus - This is a group of bacteria that can lead to various diseases.

• Neisseria Gonorrhoeae - This is the bacterium that causes gonorrhea.

• Virus - Viruses such as HIV (human immunodeficiency virus) can infect the joints of all age groups.

Pyarthrosis is a skin or urinary tract infection that spreads to joints through the bloodstream. Less commonly, bacteria can enter the joint space through a puncture wound, injection of drugs, or surgery in or near the joint (including joint replacement surgery). The lining of the joint has little ability to protect itself from infection. The body's response to infection contributes to the damage, including inflammation, which can increase pressure within joints and reduce blood flow.

What Are the Risk Factors for Pyarthrosis?

Having multiple risk factors is more risky than having only one risk factor. Risk factors for pyarthrosis include:

• Problems With Existing Joint Conditions - Chronic diseases and conditions that affect the joints, such as osteoarthritis (inflammation of joints), gout (severe pain redness in the joints), rheumatoid arthritis (inflammation of joints due to autoimmunity), and lupus (autoimmune condition leading to inflammation in various organs), can increase the risk of pyarthrosis, as can previous joint surgery and joint injuries.

• Artificial Joint - Bacteria can enter during joint replacement surgery, or artificial joints can become infected when bacteria from another part of the body reach the joint through the bloodstream.

• Taking Medicine for Rheumatoid Arthritis - People with rheumatoid arthritis are at increased risk because they are more susceptible to infections because they take drugs that suppress the immune system. Diagnosing pyarthrosis in people with rheumatoid arthritis is difficult because many of the signs and symptoms are similar.

• Fragility of Skin - Fragile, poorly healed skin can allow bacteria to enter the body. Skin conditions such as eczema and psoriasis (autoinflammation leading to skin inflammation) elevate the risk of septic arthritis (joint inflammation caused by infection), as do infected skin wounds. People who regularly inject drugs also have an increased risk of infection at the injection site.

• Weakened Immune System - People with weakened immune systems are at increased risk of pyarthrosis. This includes people with diabetes, kidney or liver problems, and those taking medications that suppress the immune system.

• Trauma to Joints - Animal bites, stings, and joint cuts can put a person at risk for septic arthritis.

What Are the Symptoms of Pyarthrosis?

Pyarthrosis usually causes extreme discomfort and difficulty using the affected joint. The joint may be swollen, red, warm to the touch or the patient might have a fever. When pyarthrosis develops in a prosthetic joint (prosthetic joint infection), signs and symptoms, such as mild pain and swelling, may appear months or years after knee or hip replacement surgery. The joints may become loose, causing pain when moving or bearing weight on the joint. Rest usually relieves the pain. In extreme cases, the joint may dislocate.

How Is Pyarthrosis Diagnosed?

The tests listed below help diagnose pyarthrosis:

• Joint Fluid Analysis - Infection can change the color, consistency, amount, and composition of the fluid in the joint. A needle can take a sample of this fluid from the affected joint.

• Laboratory Tests - It helps identify the organism responsible for the infection so doctors know what drugs to prescribe.

• Imaging Tests - X-rays and other imaging tests of the affected joint can be used to assess joint damage or loose prostheses.

• Blood Test - It can determine if there are signs of infection in the blood. A blood sample is taken from a vein with a needle.

A specialized scan that involves swallowing or injecting a small amount of a radioactive chemical may be used if the doctor suspects a prosthetic joint infection and it has been more than a year since a person has had joint surgery.

What Are the Treatment Option for Pyarthrosis?

Doctors rely on joint drainage and antibiotics to treat pyarthrosis. Listed below are some methods of treatment:

1. Joint Drainage - It is important to remove the infected synovial fluid. Drainage methods include:

• Needle Aspiration - In some cases, doctors can insert a needle into the joint space to draw out the infected fluid.
• Arthroscopic Procedure - In arthroscopy, a flexible tube with a video camera at the tip is inserted through a small incision in the joint. Suction and drainage tubes are then inserted through a small incision around the joint.
• Open Joint Surgery - Some joints, such as hips, are more difficult to drain by needle or arthroscopy and may require open surgery.

2. Antibiotics - To select the most effective antibiotics, doctors need to identify the organism causing the infection. Antibiotics are usually given first through intravenous injection. Later, the patient may be able to switch to oral antibiotics. Treatment usually lasts two to six weeks. Antibiotics carry the risk of side effects such as nausea, vomiting, and diarrhea. Allergic reactions can also occur.

3. Removal of Replaced Joint - When an artificial joint becomes infected, treatment often consists of removing the joint and temporarily replacing it with a joint spacer (a device made of antibiotic cement). A new replacement joint is implanted after a few months. If the prosthesis cannot be removed, doctors can clean the joint to remove damaged tissue and leave the prosthesis alone. Intravenous antibiotics are followed by oral antibiotics for several months to prevent recurrence of the infection.

What Are the Complications of Pyarthrosis?

If treatment is delayed, septic arthritis can lead to degeneration of joints and permanent damage. Complications such as joint loosening and dislocation can occur when septic arthritis affects an artificial joint.

Conclusion

Pyarthrosis is a painful infection of the joints caused by bacteria entering the bloodstream from another part of the body. It may also occur when bacteria enter directly into the joint leading to painful puss formation and immobility of the joint. It may also occur in people with recent joint surgery or replacement. Timely treatment and intervention may lead to improved outcomes for patients.