Low-income patients could be at increased risk for above-knee amputation (AKA), a rare but severe complication of deep infection after knee replacement surgery, suggests a study published recently in Clinical Orthopaedics and Related Research.

The journal is a publication of The Association of Bone and Joint Surgeons and is published in the Lippincott portfolio by Wolters Kluwer.

Race and sex do not affect the risk of AKA after periprosthetic joint infection (PJI), according to the new research, led by Shyam Brahmabhatt, MD, of Rothman Orthopaedic Institute, Philadelphia, in a media release from Wolters Kluwer Health.

Using data from a nationally representative hospital database (Nationwide Inpatient Sample), the researchers identified approximately 33,000 patients diagnosed with PJI after knee joint replacement surgery between 2010 and 2014. Referring to infection developing around the artificial joint implant (prosthesis), PJI itself is a serious complication, usually requiring further surgery.

In a small number of cases, treatment of the infection is unsuccessful, requiring amputation of the limb at a level above the knee. Of the 33,000 patients with PJI, about 3% had AKA. The researchers analyzed risk factors associated with AKA, focusing on socioeconomic measures (income and insurance status), race, and sex.

Socioeconomic factors were significantly related to AKA risk, even after adjustment for the patients’ health status and other characteristics. Patients living in areas (based on ZIP code) in the lowest one-fourth of income were 58% more likely to sustain an AKA, compared to those living in the highest-income areas.

Patients on public insurance were also at higher risk. Compared to those with private insurance, the odds of AKA were 94% higher for Medicare patients and 86% higher for Medicaid patients, the release explains.

The risk of AKA was not significantly different for black compared to white patients. Risk was also similar for men compared to women.

“While ZIP code may not be a perfect measure of socioeconomic status, it is associated with the level of resources that may be available to people living in that area,” Brahmabhatt says, in the release.

The researchers call for further studies to explore strategies to prevent PJI – particularly in patients from low-income areas.

“The message that I would impart is that upholding the principles of equity, social justice, and ensuring community health are important for all physicians,” Brahmabhatt concludes.

“It’s important to remember that all specialties work together as a team to fulfill vital roles in helping our patients towards that goal.”

[Source(s): Wolters Kluwer Health, EurekAlert]