Does a titanium sleeve reduce the frequency of pseudotumors in metal-on-metal total hip arthroplasty at 5–7 years follow-up?

TY - JOUR

T1 - Does a titanium sleeve reduce the frequency of pseudotumors in metal-on-metal total hip arthroplasty at 5–7 years follow-up?

AU - Hjorth, Mette Holm

AU - Egund, Niels

AU - Mechlenburg, Inger

AU - Gelineck, John

AU - Jakobsen, Stig Storgaard

AU - Søballe, Kjeld

AU - Stilling, Maiken

PY - 2016/12/1

Y1 - 2016/12/1

N2 - Introduction Little is known about pseudotumor frequency and risk factors for pseudotumor formation among different types of metal-on-metal (MoM) hip arthroplasties. A lower release of chromium and cobalt have been reported in MoM hip arthroplasties with a titanium sleeve compared to MoM designs without a titanium sleeve, but yet it is unknown whether a titanium sleeve reduces the pseudotumor frequency. We conducted a cross-sectional study to investigate: 1) pseudotumor frequency, 2) risk factors of pseudotumor formation 3) and correlations between pseudotumors, serum metal-ions, implant position, and clinical symptoms. Hypothesis We expected a lower pseudotumor frequency in MoM hip articulation with a titanium sleeve than reported in MoM hip articulation designs using chromium-cobalt sleeve. Materials and method A consecutive series of 41 patients/49 hips (31 males), mean age 52 (28–68) years, participated in a 5.5 ± 0.5 (4–6.5) year follow-up study of their M2a_Magnum hip articulation (Biomet Inc., Warsaw, Indiana, USA). Patients were evaluated with magnetic resonance imaging (MRI), measurements of serum metal-ions, plain radiographs, and clinical outcome measures of Harris Hip Score (HHS) and Oxford Hip Score (OHS). Results Eighteen of 47 hips (38%) had MRI-verified pseudotumors, all cystic, with a mean dimension of 10.6 × 25.6 × 41 mm. Digital measurements on plain radiographs revealed a higher cup anteversion in patients with a pseudotumor of mean 28.4° ± 5.05° compared to mean 23.5° ± 6.5° in patients without a pseudotumor (P = 0.009). Serum metal-ion concentrations, acetabular cup inclination and measures of HHS and OHS were similar between patients with and without a pseudotumor (P > 0.46). Conclusion At 5.5 ± 0.5 years after surgery, MRI-verified cystic pseudotumors were frequently observed in M2a_Magnum hip articulations despite the use of titanium sleeves. The pseudotumors were related to high cup anteversion angles but not related to high serum metal-ions or clinical symptoms. Level of evidence IV: cross-sectional study.

AB - Introduction Little is known about pseudotumor frequency and risk factors for pseudotumor formation among different types of metal-on-metal (MoM) hip arthroplasties. A lower release of chromium and cobalt have been reported in MoM hip arthroplasties with a titanium sleeve compared to MoM designs without a titanium sleeve, but yet it is unknown whether a titanium sleeve reduces the pseudotumor frequency. We conducted a cross-sectional study to investigate: 1) pseudotumor frequency, 2) risk factors of pseudotumor formation 3) and correlations between pseudotumors, serum metal-ions, implant position, and clinical symptoms. Hypothesis We expected a lower pseudotumor frequency in MoM hip articulation with a titanium sleeve than reported in MoM hip articulation designs using chromium-cobalt sleeve. Materials and method A consecutive series of 41 patients/49 hips (31 males), mean age 52 (28–68) years, participated in a 5.5 ± 0.5 (4–6.5) year follow-up study of their M2a_Magnum hip articulation (Biomet Inc., Warsaw, Indiana, USA). Patients were evaluated with magnetic resonance imaging (MRI), measurements of serum metal-ions, plain radiographs, and clinical outcome measures of Harris Hip Score (HHS) and Oxford Hip Score (OHS). Results Eighteen of 47 hips (38%) had MRI-verified pseudotumors, all cystic, with a mean dimension of 10.6 × 25.6 × 41 mm. Digital measurements on plain radiographs revealed a higher cup anteversion in patients with a pseudotumor of mean 28.4° ± 5.05° compared to mean 23.5° ± 6.5° in patients without a pseudotumor (P = 0.009). Serum metal-ion concentrations, acetabular cup inclination and measures of HHS and OHS were similar between patients with and without a pseudotumor (P > 0.46). Conclusion At 5.5 ± 0.5 years after surgery, MRI-verified cystic pseudotumors were frequently observed in M2a_Magnum hip articulations despite the use of titanium sleeves. The pseudotumors were related to high cup anteversion angles but not related to high serum metal-ions or clinical symptoms. Level of evidence IV: cross-sectional study.

KW - Clinical outcome measures

KW - Magnetic resonance imaging

KW - Metal-on-metal total hip arthroplasty

KW - Pseudotumor

KW - Serum metal-ion levels

KW - Titanium sleeve

UR - https://www.scopus.com/pages/publications/84998773613

U2 - 10.1016/j.otsr.2016.08.020

DO - 10.1016/j.otsr.2016.08.020

M3 - Tidsskriftartikel

C2 - 28341265

SN - 1877-0568

VL - 102

SP - 1035–1041, 739

JO - Orthopaedics & Traumatology: Surgery & Research

JF - Orthopaedics & Traumatology: Surgery & Research

IS - 8

ER -