TY - JOUR

T1 - Assessing osteonecrosis of the femoral head after internal fixation of femoral neck fractures

T2 - MARS MRI versus conventional radiography and patient-reported outcomes

AU - Kindt, Mikael

AU - Jönsson, Maria L.

AU - Torfing, Trine

AU - Strøm Rönnquist, Sebastian

AU - Viberg, Bjarke

AU - Overgaard, Søren

AU - Rogmark, Cecilia

N1 - Funding Information: HFU-60 was approved by ethical review boards in Sweden (Regionala etikprövningsnämnden Lund, Dnr: 2015/28) and Denmark (Videnskabsetisk Komité for Region Syddan-mark, projekt ID: s-20150137), registered at ClinicalTrials. gov (NCT03848195), and conducted in accordance with the Helsinki declaration. All participating patients gave their written informed consent. Data may be shared upon reasonable request. The HFU-60 project was supported by grants from the Greta and Johan Kock Foundation, A. Påhlsson Foundation, H. Järnhardt foundation, Skåne University Hospital Research Fund, the Research and Development Council of Region Skåne, the Swedish Research Council funding for clinical research in medicine, and “Region Syddanmarks for-skningsfond” from the Region of Southern Denmark. None of the funders had influence on the scientific work of this study. None of the authors have any financial or competing interests. Completed disclosure forms for this article following the ICMJE template are available on the article page, doi: 10.2340/17453674.2023.11658 Publisher Copyright: © 2023 The Author(s).

PY - 2023

Y1 - 2023

N2 - Background and purpose — Little is known on the use of metal artifact reduction sequence (MARS) MRI to diagnose osteonecrosis of the femoral head (ONFH) after fixation of femoral neck fractures (FNF) with conventional metal implants present. We compared MARS MRI with radiography in diagnosing ONFH. Secondarily, we determined whether signs of ONFH on MARS MRI correlate with patient-reported outcomes (PROs) via Oxford Hip Score (OHS) and pain (VAS). Patients and methods — 30 adults under 60 years treated with internal fixation after FNF were prospectively included (2015–2018) at 2 hospitals. They were followed up with radiography and PROs at 4, 12, and 24 months and MARS MRI at 4 and 12 months. OHS < 34 or VAS pain > 20 was considered significant. Results — At 12 months, 14 patients had a pathological MRI. 3 of 14 had ONFH on radiographs at 12 months, increasing to 5 at 24 months, and 4 had unfavorable PROs. 2 of 5 patients with ONFH signs on both MRI and radiography had unfavorable PROs. 1 of 10 patients with normal MRI and radiography had unfavorable 2-year PROs. 4 patients had inconsistent MRI results, of which 1 developed ONFH. 1 patient dropped out. Conclusion — Information from a pathological MRI was not useful, as a majority remained free from symptoms and ONFH signs on radiographs. Furthermore, PROs did not correlate with imaging results. MARS MRI findings must be better understood before being taken into clinical practice. However, a normal MARS MRI seems to be a good prog-nostic finding.

AB - Background and purpose — Little is known on the use of metal artifact reduction sequence (MARS) MRI to diagnose osteonecrosis of the femoral head (ONFH) after fixation of femoral neck fractures (FNF) with conventional metal implants present. We compared MARS MRI with radiography in diagnosing ONFH. Secondarily, we determined whether signs of ONFH on MARS MRI correlate with patient-reported outcomes (PROs) via Oxford Hip Score (OHS) and pain (VAS). Patients and methods — 30 adults under 60 years treated with internal fixation after FNF were prospectively included (2015–2018) at 2 hospitals. They were followed up with radiography and PROs at 4, 12, and 24 months and MARS MRI at 4 and 12 months. OHS < 34 or VAS pain > 20 was considered significant. Results — At 12 months, 14 patients had a pathological MRI. 3 of 14 had ONFH on radiographs at 12 months, increasing to 5 at 24 months, and 4 had unfavorable PROs. 2 of 5 patients with ONFH signs on both MRI and radiography had unfavorable PROs. 1 of 10 patients with normal MRI and radiography had unfavorable 2-year PROs. 4 patients had inconsistent MRI results, of which 1 developed ONFH. 1 patient dropped out. Conclusion — Information from a pathological MRI was not useful, as a majority remained free from symptoms and ONFH signs on radiographs. Furthermore, PROs did not correlate with imaging results. MARS MRI findings must be better understood before being taken into clinical practice. However, a normal MARS MRI seems to be a good prog-nostic finding.

U2 - 10.2340/17453674.2023.11658

DO - 10.2340/17453674.2023.11658

M3 - Journal article

C2 - 36999919

AN - SCOPUS:85153229702

VL - 94

SP - 135

EP - 140

JO - Acta Orthopaedica

JF - Acta Orthopaedica

SN - 1745-3674

ER -