Study shows trends in THA implant usage
From 2001 to 2012, total hip arthroplasty implant usage trends favored cementless fixation, metal-on-polyethylene or ceramic-on-polyethylene bearings, modular acetabular cups and large diameter femoral heads, according to study results.
“There are specific trends in evolution in the utilization of total hip arthroplasty implants,” Kevin J. Bozic, MD, MBA, William R. Murray professor and vice chair of orthopedic surgery at the University of California, San Francisco, told Orthopedics Today. “It is important for clinicians and physicians to understand those trends and how they impact clinical practice and clinical outcomes for our patients.”
Kevin J. Bozic
Implant utilization trends
Bozic and his colleagues analyzed 105,291 total hip arthroplasty (THA) procedures to evaluate trends in implant utilization across 174 hospitals throughout the United States using the Orthopedic Research Network. The investigators found an increase in cementless THA constructs from 46% in 2001 to 93% in 2012, with cementless stems used 94% of the time and cemented stems used 5.8% of the time. There was a decrease in the use of metal-on-highly cross-linked polyethylene bearings for primary THA from 63% in 2011 to 59% in 2012, as well as a decrease in ceramic-on-ceramic bearings from 11% in 2004 to 1% in 2012.
Although the researchers found a decline in use of metal-on-metal implants from 11% in 2010 to 1% in 2012, there was an increase in the use of ceramic heads and polyethylene liners from 6% in 2001 to 38% in 2012. Of the acetabular cups used in 2012, modular two-piece cups accounted for 99% and one-piece acetabular cups accounted for 1%.
Among the acetabular liners used in 2012, 98% were highly cross-linked polyethylene. In addition, 61% of the femoral heads used in primary THA were metal vs. 39% of ceramic heads. Overall, 51% of femoral heads were 36 mm and 28% were 32 mm.
“I think it is important for us as clinicians to understand these trends and what is driving them,” Bozic said. “Many of them are not based on evidence, but based on surgeon preference and marketing. It is important for us to understand, as our use of technology evolves, what the implications are for clinical outcomes and to be clinical and scientific in the way we evaluate outcomes so we are not changing technology without a good rationale in understanding how those changes influence our practice.”
According to Bozic, the Orthopedic Research Network is one of the largest registries that includes information about specific implant utilization in the country, and represents about 3% of the utilization in the United States. Future research will focus on evaluating implant utilization for total knee arthroplasty, as well as promoting and expanding a national registry with public information representative of the entire country, specifically the American Joint Replacement Registry (AJRR).
“Now we are trying to do the same [study] in total knee arthroplasty implant utilization,” Bozic said. “We are also using this information to make a stronger case for participation in the AJRR so we can understand implant utilization trends on a larger scale.” – by Casey Tingle
Lehil MS. J Arthroplasty. 2014;doi:10.1016/j.arth.2014.05.017.
For more information:
Kevin J. Bozic, MD, MBA, can be reached at the University of California, San Francisco, Department of Orthopaedic Surgery, Core Facility, Philip R. Lee Institute for Health Policy Studies, 500 Parnassus, MU 320 W. San Francisco, CA; email: email@example.com.
Disclosure: Bozic is the chair of the California Joint Replacement Registry.