Erratum to: Clin Orthop Relat Res DOI 10.1007/s11999-016-4981-2

In the published study, “What Is the Natural History of Asymptomatic Pseudotumors in Metal-on-metal THAs at Mid-term Followup?” the second sentence in the Patients and Methods section incorrectly described a cohort of 71 patients as having “no pseudotumors identified on ultrasound scan at early followup”.

The sentence should read: “From the 360 patients who underwent MoM THA, we identified a representative cohort of 71 patients who were clinically asymptomatic, had ultrasound scan at early followup, and had previously been evaluated for two other studies [12, 27].”

Additionally, the first two sentences under the subhead “Revision Procedures for Pseudotumors” in the Patients and Methods section are unclear.

The sentences should read: “In 2014 (a minimum 6.5 years from surgery; maximum, 9 years; mean, 7 years), after ethical approval, the clinical records of these 71 patients who were asymptomatic at the time of the authors’ earlier studies [12, 27], which reported on them at 3.5 years (3 to 5 years), were reviewed. In the years that followed, an additional eight patients became symptomatic and were revised at a mean of 5 years (3 to 6 years) since surgery. This left 63 patients in the present group with no symptoms from the hip, who underwent imaging and serum tests as described herein.

The authors apologize for these errors.