Pediatric Septic Arthritis - Causes, Symptoms, Diagnosis, and Treatment

What Is Septic Arthritis?

Septic arthritis is an infection that affects the joints of the body. In this type of infection, the synovial fluid or the lubricant of the joints is affected. It may also affect the joint cavity. In most cases, the infection reaches the joint cavity through the bloodstream. But in some cases, the joint cavity can also be affected when it is opened for surgery or exposed during an injury.

The infection of the joint cavity can be caused due to bacterial, fungal, or even viral infections. In most cases, it is the bacteria that causes the infection. In some cases, the infection may also spread to the bones.

Where Does Septic Arthritis Affect?

In children, septic arthritis affects only one joint of the body. Septic arthritis can affect the joints of-

1. Elbow joint.

2. Wrist joint.

3. Hip joint.

4. Shoulder joint.

5. Pelvic joint.

6. Ankle.

Which Organisms Cause Septic Arthritis?

Septic arthritis is a condition in which the infection is caused by a microorganism. These microorganisms can be bacteria, viruses, or even fungi. However, bacteria are the most common causative organism. The various types of bacteria that can cause the infection include-

• Streptococci.

• Staphylococci.

• Haemophilus influenza.

• Other gram-negative bacilli.

What Are the Causes of Septic Arthritis?

The various causes of septic arthritis include-

• Fractures: Fractures can be one of the most common causes of septic arthritis. A fracture can expose the bone and the joint to the external surface. This can act as a cause for the growth of the bacteria. Sometimes, septic arthritis can also occur during surgery to correct the fracture.

• Wounds: Wounds can be one of the most common predisposing factors of a septic infection. The wound, when deep, can expose the surface to germs. This can then be a breeding ground for the various organisms that can cause septic arthritis.

• Infections: Septic arthritis can occur when infection from other body parts spreads to the joints. In such cases, an infection from within the body is a source. Such infections can occur anywhere from the skin or other bones. Infection travels through the bloodstream in such cases.

• Foreign Object: In some cases of trauma or injury, a foreign object can get lodged in the body. This foreign object act as the source of infection in the body.

What Are the Signs and Symptoms of Pediatric Septic Arthritis?

Symptoms of pediatric arthritis vary from case to case. The site of infection, the source, and the age of the affected child determine the symptoms of this condition. The joint that is affected determines the source of the infection. This condition is known to have a very rapid onset. The affected joint can show signs of restricted mobility, severe pain, and even swelling within a few hours after the infection. The most common symptoms of this condition include:

• Severe pain in the joint that is affected.

• Redness and swelling of the affected joint. The region around the affected joint can also feel warm to the touch. These are typical signs of inflammation. An infection can be a primary cause of any infection.

• Restricted mobility of the affected joint.

• Inability to move the affected joint.

• There could also be limping.

• There could also be other symptoms, such as fever and vomiting.

• The child may be irritated or crying continuously.

• The child may constantly place a hand over the affected joint.

How Is Pediatric Septic Arthritis Diagnosed?

A prompt diagnosis is necessary to prevent any permanent damage to the joints or the bones. The diagnosis is achieved by comparing various factors and collecting a detailed case history. A detailed physical examination and medical history are necessary to arrive at a diagnosis. Various diagnostic tests may also be performed in order to achieve the most accurate diagnosis. The various diagnostic methods may include:

• Bacterial Culture: A bacterial culture involves the removal of the infected bacterial tissue and cultivating the tissue in a certain culture. It helps in identifying the causative organism. When this is identified, the treatment also becomes easy as the most suitable antibiotic treatment can be given.

• Blood Test: Blood tests can be performed to evaluate the blood parameters. These blood parameters can be indicative of an infection.

• X-ray: X-rays can be used to study the affected bone and the joint. X-rays can help in identifying the site of infection.

• Scans: Various scans may be performed to identify the site of the infection. It also helps in assessing the extent of damage to the bone and the joints. This may include a CT (computed tomography) and an MRI (Magnetic resonance imaging) scan—these help in assessing the hard and soft tissue components of the joint.

• Ultrasound: An ultrasound is useful in analyzing if there is any accumulation of inflammatory fluid in the joint. Ultrasound can also be used in the treatment of this condition. An ultrasound can guide in a needle-guided retrieval of the fluid accumulated in the joint cavity.

How Is This Condition Treated?

The treatment for this condition depends on the overall progression of the condition and the medical history. The treatment for this condition is based on the following conditions:

• The organism that is causing this condition. It helps in curating the most accurate medications for the condition.

• The various allergies and conditions of the child who is being treated.

• The expectant course of the condition.

• Since this condition is of acute nature, the medication is delivered through an intravenous route. This helps in a quicker recovery from the condition. But antibiotics are effective only if the conditions are caused by bacteria. If the condition is caused by other organisms, such as fungi or viruses, the treatment and the medications can be altered accordingly.

• However, any treatment is supplemented with painkillers. This can ease the pain and help the child both mentally and physically.

• In some cases, surgery may be required to clean and drain the infected site. Sometimes, just the antibiotic is not enough to clean the infection entirely. The site of infection can be drained with the help of a tube or a needle.

What Are the Complications of This Condition?

The following may be the complications of this condition:

• The area surrounding the joint and the bone can be affected.

• Inability or reduced movement of the affected joint.

• The growth plate present in the joint can be affected. This can, in turn, affect the future growth of joints.

• The growth of the limb itself can be affected.

Conclusion:

Faster this condition is treated, the lesser the long-term effects on the joint and the surrounding tissue. These conditions can occur when a child has a fracture or an open injury. This can cause bacterial growth in the joints leading to sepsis. Septic arthritis is an acute condition and can progress very fast. It can present with symptoms such as painful and immobile joints. It is essential to diagnose this condition at the earliest and give the best treatment possible in order to have the best prognosis and prevent complications.