Higher Level of Wear in Pseudotumor Hip Revisions
High linear, volumetric, edge wear in hip resurfacing implants due to pseudotumors
TUESDAY, Dec. 13 (HealthDay News) -- The hip resurfacing implants of patients who undergo revision for pseudotumors have significantly higher linear, volumetric, and edge wear rates than implants of patients who undergo revision for other reasons, according to a study published in the Dec. 7 issue of The Journal of Bone & Joint Surgery.
Siôn Glyn-Jones, D.Phil., from the University of Oxford in the United Kingdom, and colleagues compared the location and magnitude of wear on hip resurfacing devices obtained during revision procedures for pseudotumors and for other reasons (control group). Patient demographics and implant orientation were recorded for 18 implants from patients with pseudotumors and 18 controls. The surface of the femoral and acetabular components were scanned to a resolution of 20 nm, and evaluated for linear, volumetric, and edge wear.
The investigators found that the femoral and acetabular components in the pseudotumor group showed three times more total linear wear, and over six times more total volumetric wear than the components in the control group. The pseudotumor group had a significantly greater mean linear wear rate and standard deviation of the femoral components than the control group. The pseudotumor group also had a significantly greater volumetric wear rate of the femoral components than the control group. Edge wear was found in 17 participants from the pseudotumor group, and six from the control group.
"Implants that were retrieved because of pseudotumor had a significantly higher wear rate and prevalence of edge wear than the control implants did," the authors write. "However, not all patients with high wear developed pseudotumors, and not all pseudotumors had high wear."
One or more of the study authors disclosed financial ties to an entity in the biomedical arena.