Shoulder Infections (Septic Arthritis)
Overview
For patients in Richmond, VA seeking specialized care, understanding the mechanics of shoulder infections is the first step toward recovery. A true infection of the shoulder joint (septic arthritis) is a medical emergency and patients should call 911. Bacteria can enter the joint via the bloodstream (for example, from a dental abscess or UTI) or from a direct injection/surgery. The bacteria release enzymes that rapidly digest the articular cartilage. A joint can be destroyed in a matter of days if untreated.
Another form of a shoulder infection is a chronic infection. This is usually at a surgical site, like a prior shoulder replacement. This is called a prosthetic joint infection (PJI). Similar to an acute infection, it can happen spontaneously. However, the presentation of extreme pain and unwillingness to move the arm is usually less intense, and often even comes on slowly over days to months. It may be barely noticed at all except for minor discomfort, which is due to the bacteria that is commonly implicated here being a relatively less aggressive bacteria. It’s name is Cutibacterium acnes (C. acnes, formerly called Propionibacterium acnes, P. acnes) and it lives on everyone’s skin, at higher concentrations around the shoulder. This presentation of minor pain after a shoulder replacement is not just a symptom of a PJI, but a shared symptom of many causes for a failed shoulder replacement and always warrants an investigation.
To make this diagnosis, an exam and aspiration (using a needle to remove fluid from the joint) are necessary. The full treatment regimen is often decided by an orthopaedic surgeon and an infectious disease specialist.
Symptoms
The "Hot" Joint: The shoulder is red, swollen, and warm.
Fever/Chills: Systemic signs of illness.
Refusal to Move: The patient holds the arm rigidly against the body; any attempt to move it causes excruciating pain.
Wound Issues: For patients who have already had surgery, part of their wound may open up and begin draining.
Management
The management of a shoulder infection depends on your medical and surgical history. Generally speaking though, if a shoulder develops severe pain to the point that one cannot move it, a shoulder infection is possible and pateints should call 911.
Aspiration: We must draw fluid from the joint to test for white blood cell count and culture bacteria.
Urgent Surgery: Antibiotics alone cannot penetrate a joint well enough. The joint must be physically washed out.
Delayed, Planned Surgery: Only in the case of a chronic infection (PJI). Your surgeon needs to isolate the reason why you seem to have a failed shoulder arthroplasty and if it is an infection, then typically a conversation about the most appropriate workup and treatment happens next on a case by case basis.
Surgical Solutions
Shoulder Debridement – An arthroscopic procedure called an “irrigation and debridement” is how orthopaedic surgeons wash out infected joints. Occasionally, shoulders need to undergo this surgery in an open, instead of arthroscopic, fashion.
Revision Shoulder Arthroplasty – If an implant is infected, it must be removed, unless it was put in within the past few weeks. Revision shoulder arthroplasty for infection can be done in one or two stages and the decision depends on the scenario. In a one-stage revision, everything that is infected is removed, the joint is washed out, and new shoulder replacement implants are put back in, sometimes using antibiotic cement. In a two-stage revision, everything that is infected is removed, the joint is washed out, and a temporary antibiotic spacer made of cement is placed and left for around 6 weeks. No matter which surgery a patient undergoes, they almost always get 6 weeks of IV antibiotics afterwards. For the two-stage revision patients, once the antibiotics are done and the infectious disease doctors give their approval, the second stage surgery may occur and the temporary spacer is removed and real shoulder replacement implants are put back in.