According to a systematic review published online September 9th in the BMJ, there is no evidence to support the use of 5 newer joint replacement devices compared to analogous products that have been on the market longer. In fact, the risk of undergoing revision surgery is higher with some of the newer systems.
The study was led by Marc J. Nieuwenhuijse, MD, PhD from the Patient Centered Comparative Effectiveness Program and US Food and Drug Administration Medical Device Epidemiology Science and Infrastructure Center, Department of Public Health, Weill Cornell Medical College, New York, City; the Department of Orthopaedics, Leiden University Medical Center, the Netherlands; and the Office of Surveillance and Biometrics, Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, MD. He and his colleagues wrote that “[N]ew technologies are being introduced to the commercial market without sufficient high quality evidence for improved benefit over existing, well proven, and safe alternative implant solutions…[T]he status quo regarding the introduction of new device technologies is not acceptable.”
The researchers focused on five joint replacement devices that were supposedly superior to older products serving the same function:ceramic-on-ceramic bearings, modular femoral necks, uncemented monoblock cups, high flexion knee replacement and gender specific knee replacement. These devices were selected based on three criteria. There must have been a reason as to why they might be better, be 90 percent completed in a national orthopedic registry and be comparable to a traditional device used for the same purpose.
Metal-on-metal hip replacements were not included in the study. These devices have come under serious scrutiny in light of safety concerns. Last year, the U.S. Food and Drug Administration (FDA) cautioned that these devices can release metal debris have a higher rate of revision surgery.
The review encompassed 118 studies involving a total of 15,384 implants in 13,164 patients. In 4 out of 5 devices, there was no evidence of clinical improvement. The fifth device, modular femoral necks, had insufficient evidence. For uncemented monoblock hip replacements and sex-specific knee replacements, the rate of revision was similar to that of older devices. The other three, have a significantly higher rate of revision. In modular femoral neck replacements, the revision rate was nearly doubled with a hazard rate of 1.92. The hazard ratio for high-flexion knee replacements ranged from 1.0 to 1.76 among 56 studies; ceramic-on-ceramic hip replacements had an elevated risk ranging from 1.0 to 1.55 compared to ceramic-polyethylene in 42 studies.
The authors concluded that there should be a more rigorous process to clear changes to devices such as joint replacements.