Anterior Approach To Hip Replacement Procedures May Increase Risk Of Complications: Study

A form of hip replacement surgery meant to require a smaller incision and less scarring could actually increase the risk of surgical complications, according to the findings of a new study.

Canadian researchers report that patients who underwent anterior total hip arthroplasty faced double the risk of major surgical complications when compared to other approaches to the procedure. Their findings were published on March 17 in the Journal of the American Medical Association (JAMA).

Anterior total hip arthroplasty is a non-traditional approach to hip replacement surgery, which allows the surgeon to conduct the replacement via a small incision in the front of the hip. More traditional methods involve lateral or posterior approaches.

The anterior approach is promoted as causing less pain, muscle trauma, and resulting in quicker recovery with a shorter hospital stay.

Researchers with the University of Toronto conducted a population-based retrospective cohort study of all adults in Ontario, Canada who had undergone hip replacement from April 1, 2015 through March 31, 2018, involving more than 30,000 patients.

According to the findings, 10% of patients underwent the anterior approach, while 70% underwent a lateral procedure and 20% underwent a posterior approach. After a year of follow up, the researchers found that 2% of the anterior approach patients suffered major surgical complications, compared to only 1% of those who had undergone lateral or posterior procedures.

“Among patients undergoing total hip arthroplasty, an anterior surgical approach compared with a posterior or lateral surgical approach was associated with a small but statistically significant increased risk of major surgical complications,” the researchers concluded. “The findings may help inform decisions about surgical approach for hip arthroplasty, although further researcher is needed to understand pain and functional outcomes.”

Hip Implant Problems

Hip replacement systems have been under close scrutiny in recent years, following a number of high profile recalls and problems.

Probably the most problematic have been metal-on-metal hip replacements sold by a number of different manufacturers, which featured a metal femoral head that rotates within a metal acetabular cup.

Unlike other artificial hip designs, which typically feature metal-on-ceramic or metal-on-plastic, the metal-on-metal hips have been found to release microscopic metallic debris as the parts rub against each other. This can lead to increased levels of metal ions in the blood, known as metallosis. This has been linked to reports of loosening and failure, often within a few years after the artificial hip is implanted.

Metallosis has been linked to tissue damage, tumors and may increase the risk of cancer according to some research.

Most of the devices were introduced in the U.S. through the controversial fast-track 510(k) approval process, which only required that the device be a “substantial equivalent” to an already existing device approved by the FDA. However, the snowball effect of the substantial equivalence test has allowed many devices now considered unreasonably dangerous and defective to be implanted in thousands of Americans.

Several manufacturers faced metal-on-metal hip lawsuits in recent years, claiming that the design was unreasonably dangerous and prone to early failure. Similar allegations led to DePuy ASR hip lawsuits, DePuy Pinnacle hip lawsuits and other cases.