What is a Musculoskeletal Infection?
A musculoskeletal infection is the invasion of an individual’s muscles, bones, or joints by disease-causing organisms, their multiplication, and the reaction of the individual’s body tissues to these organisms and the toxins they produce. Most musculoskeletal infections are usually caused by bacteria. Infection in the bones, joints, or muscles may occur at any age and can spread swiftly through an individual’s blood, bones, and tissues.
Types of Musculoskeletal Infections
Some of the types of musculoskeletal infections include the following:
- Septic arthritis: Septic arthritis, also known as infectious arthritis, is a painful infection of the joint. The infection can occur from bacteria that spread through the bloodstream from another area of the body. Septic arthritis can also occur due to a penetrating injury that delivers germs directly into the joint. Infants and older adults are most likely to develop septic arthritis. Knees are most commonly affected, but septic arthritis also can affect hips, shoulders, and other joints.
- Septic bursitis: Septic bursitis is a painful condition that affects the joints. Bursae are fluid-filled sacs that act as a cushion between bones, tendons, joints, and muscles. When these sacs become inflamed due to infection, usually with bacteria, it is called septic bursitis.
- Osteomyelitis: Osteomyelitis is an infection of the bone that can occur in any age group. It can be caused by bacteria in the bloodstream from infectious diseases that spread to the bone, an open wound from an injury over a bone, and recent surgery or injection in or around a bone. Smokers and people with diabetes or kidney failure are at increased risk of developing osteomyelitis.
- Myositis (soft tissue infections): Myositis refers to inflammation of the muscles that can be caused by an infection, injury, or autoimmune disease. There are various types of myositis, the most common being polymyositis and dermatomyositis. Polymyositis causes muscle weakness, mostly in the muscles nearest to the trunk of the body. Dermatomyositis causes muscle weakness as well as a skin rash. The main muscles to be affected by myositis are the shoulders, hips, and thighs.
- Pyomyositis: Pyomyositis is an acute bacterial infection of the skeletal muscle that results in pain and tenderness of the affected muscle and localized abscess formation. If left untreated, the abscess may extend into the bone and joint or blood poisoning may occur. It most commonly affects the muscles of the limbs and torso. Approximately 90% of cases are caused by the bacterium, Staphylococcus aureus. Treatment generally includes surgical drainage of the abscess and antibiotics.
- Infectious tenosynovitis: Tenosynovitis is an infection of a tendon and its protective sheath that results in inflammation of the tendon and synovial sheath. This infection is most common in the finger, hand, or wrist but can occur in any part of the extremities where a tendon glides within a synovial-lined fibro-osseous sheath.
- Cellulitis: Cellulitis is a common bacterial infection of the skin and the soft tissues underneath. It occurs when bacteria enter a break in the skin and spreads. It most often affects the skin of the lower legs, although the infection can occur anywhere on your body or face. Without treatment, the infection can spread quickly and may travel to lymph nodes and into the bloodstream leading to a blood infection or permanent damage of lymph vessels.
- Abscess: Abscesses are collections of pus in confined tissue spaces, usually caused by a bacterial infection or when germs enter the body through an open wound like a cut. Abscesses can occur in the skin, soft tissue, muscle, or even bones, causing inflammation at the site of infection and a cavity filled with pus.
Symptoms of Musculoskeletal Infections
Some of the common symptoms associated with musculoskeletal infections include:
- Pain and tenderness
- Difficulty moving the limbs
- Difficulty in weight-bearing
- Abscess formation
Complications of Musculoskeletal Infections
Some of the common complications associated with musculoskeletal infections include:
- Growth deformity
- Joint dysfunction
- Long-term morbidity
Diagnosis of Musculoskeletal Infections
Your doctor will review your medical history and conduct a thorough physical examination to carefully observe the areas around the affected limb as well as feel for pain. Your doctor may also try to gently move the joints to check for adequate range of motion. Your doctor may also take vital signs such as checking your temperature. In order to confirm a specific condition and form a precise diagnosis, further diagnostic tests may also be ordered, such as:
- Laboratory tests to check for infection
- X-rays to look for changes in the bone
- MRI for detailed images of the structures
- Ultrasound for detailed images of the soft tissue structures
- Bone scan to check the condition of the bones
Treatment for Musculoskeletal Infections
Antibiotics are the first-line of treatment for musculoskeletal infections. Bone infections are normally treated with antibiotics for 4 to 6 weeks, whereas joint and muscle infections are usually treated for 3 weeks. Once the infection is controlled in the hospital, most patients can receive treatment at home with oral antibiotics.
Surgery may be required to remove infected material (pus) from the area of infection. This reduces pressure and inflammation and improves blood flow, which makes it easier for the antibiotics to reach the infected area. During surgery to drain the infection, your surgeon cleans the inside of the tendon sheath to wash away pus and germs and may remove damaged or dead tissue to allow remaining tissue to heal.
In the case of septic arthritis, surgery normally will be required to wash the bacteria out of the joint. In some cases, septic arthritis may be treated by using a needle to draw the infected fluid out of the joint. For severe infections, a person may require surgery more than once to completely remove any infection.