Metal-on-metal, ceramic-on-ceramic surfaces for THA not linked to excess cancer risk

In patients undergoing total hip arthroplasty (THA), the use of metal-on-metal (MoM) or ceramic-on-ceramic (CoC) bearing surfaces does not appear to increase the risk of cancer, a recent study has found.

Researchers enrolled 156,516 patients who had undergone conventional stemmed (cs) THA procedures and 11,321 with resurfacing (rs) THA procedures. Cancer rates were determined by linking the Australian Orthopaedic Association National Joint Replacement Registry to the Australasian Association of Cancer Registries database.

Compared with the general Australian population, the incidence rates of all-cause cancer were significantly higher in csTHA (standardized incidence ratio [SIR], 1.24, 95 percent confidence interval [CI], 1.22–1.26) and rsTHA (SIR, 1.74, 95 percent CI, 1.39–2.04) patients.

However, MoM and CoC bearing surfaces appear to have no significant impact on cancer risk for csTHA procedures (MoM: hazard ratio [HR], 1.01, 95 percent CI, 0.96–1.07; CoC: HR, 0.98, 95 percent CI, 0.94–1.02), as compared with metal-on-polyethylene (MoP) and ceramic-on-polyethylene (CoP) surfaces.

Meanwhile, rsTHA procedures led to a significantly lower risk of all-cause cancer than MoP and CoP surfaces (HR, 0.85, 95 percent CI, 0.78–0.91).

“Similar to other large cohort studies, we have identified that cancer burden is generally higher in the cohort of patients receiving total hip arthroplasty procedures,” the researchers said, pointing out that such risk elevation was not observed for MoM and CoC bearing surfaces.

“Longer-term follow-up studies will be required to confirm these results for cancers with potentially longer latency periods,” they added.