5 Risks for Having an Infection of a Joint Replacement

Joint Replacement Infections

Infection is a serious complication of joint replacement surgery. Don Farrall / Getty Images

 Infection can be one of the most devastating complications of a joint replacement surgery.  While the vast majority of joint replacements turn out very well, infection can require additional surgery, discomfort, and may lead to long-term problems even if the infection is cured.

The focus of your surgeon is to prevent the chance of infection, but even with great effort, sometimes infections occur.  Certain people are more prone to having infection of a joint replacement.  Here are some of the reasons that can put patients at a higher risk for developing an infection of their hip replacement or knee replacement surgery.

Poor Nutrition

food healthy
Poor nutritional health can weaken the immune system and make infection more likely. Brett Stevens / Getty Images

Several studies have found a link between poor nutrition and developing surgical infections after joint replacement.  Low laboratory levels of leukocytes (white blood cells) and albumin have been correlated with a 5-7 times increased risk for developing an infection.  While it is not clear that addressing nutritional deficiencies will necessarily bring the risk back to normal, the data does suggest that patients with these laboratory finding may benefit from preoperative nutritional assessment and supplementation.


diabetes blood sugar
A woman checks her blood sugar level. Blend Images - Jose Luis Pelaez Inc / Getty Images

Poorly controlled diabetes is a risk factor for infection of a joint replacement.  While blood glucose is sometimes used to assess blood sugar control, more commonly doctors look at the hemoglobin A1c.  The hemoglobin A1c givens an indication of the control of diabetes over a several month time-frame, not just a single snapshot. 

Because the likelihood of developing infection is so much higher in poorly controlled diabetics, many joint replacement surgical programs will postpone elective joint replacement surgery until the blood sugar is brought under good control.


obesity weight
Body mass index can help to predict the likelihood of infection. Peter Dazeley / Getty Images

The body mass index, or BMI, is the most commonly used tool to classify obesity.  When people are morbidly obese, or have a BMI greater than 40, their risk of developing an infection after joint replacement is very high.  For example, in one large study, the risk of developing a joint replacement infection was about 0.5% overall.  In patients who were morbidly obese, the risk was almost 5%.

One of the great challenges of arthritis in obese patients is that it is extremely hard to lose weight when joint pain is severe.  Doctors should work with patients to identify low-impact exercise options, educate about nutritional improvement, and counsel patients about their potential for being at higher risk of infection.

Long Surgical Time

A longer surgical time is associated with a higher chance of infection. Fuse / Getty Images

You want a surgeon who will take enough time to properly align and insert your joint replacement, but you should also find a surgeon who is efficient.  Taking more time to perform the surgery exposes the wound for a longer period and increases the chance of infection.  This is one reason why some surgical centers are only allowing surgeons who perform joint replacements regularly to operate.  While the exact number is controversial, most centers agree that surgeons should perform at least 25-30 joint replacements every year to remain proficient. 

Rheumatoid Arthritis

Rheumatoid arthritis can increase chance of infection. Adjusting medications may help lower that risk. Rick Gomez / Getty Images

 Rheumatoid arthritis (RA) is an autoimmune condition that may cause joint damage leading to the need for replacement surgery.  One of the particular concerns for RA patients is the medications they often use to help treat their condition.  These medications can interfere with normal function of the immune system, and make infection more likely.  Typically, the medications used to diminish the immune response, called disease-modifying antirheumatic drugs, are held for a short time before and after surgery to lower the chance of these interfering with the normal immune system.


Daines BK, Dennis DA, Amann S. "Infection Prevention in Total Knee Arthroplasty" J Am Acad Orthop Surg June 2015 vol. 23 no. 6 356-364.

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