Failed Total Hip Arthroplasty: Diagnostic Performance of Conventional MRI Features and Locoregional Lymphadenopathy

Domenico Albano1,2, Carmelo Messina1,3, Luigi Zagra4

  • 1IRCCS Istituto Ortopedico Galeazzi, Unità Operativa di Radiologia Diagnostica ed Interventistica, Milan, Italy.

Abstract

Insights

New MRI lymph nodal indices show promise for diagnosing total hip arthroplasty (THA) infection. These indices, particularly those measuring node number, offer improved accuracy over conventional MRI features in identifying infection in failed THA cases.

Area of Science:

  • Radiology
  • Orthopedic Surgery
  • Infectious Disease

Background:

  • Diagnostic performance of MRI for total hip arthroplasty (THA) infection is not well-established.
  • Limited published data exists on MRI's utility in diagnosing THA infections.

Purpose of the Study:

  • To evaluate the diagnostic performance of conventional MRI features for THA infection.
  • To assess novel lymph nodal indices for identifying infection in patients with failed THA.

Main Methods:

  • A retrospective study of 119 patients with failed THA was conducted.
  • Conventional MRI features and lymph node indices (RNS, RNN, DNS, DNN) were analyzed.
  • Statistical tests including Mann-Whitney U and chi-square were employed.

Main Results:

  • Lymph nodal indices (RNN, RNS) demonstrated high accuracy (up to 93.1%) in differentiating infected from non-infected THA.
  • Conventional MRI features showed variable accuracy, with synovitis/lamellated synovitis having high specificity (97.5%).
  • Effusion/bone edema (76.3%) and synovitis (81.5%) showed higher sensitivity and accuracy, respectively, among conventional features.

Conclusions:

  • Conventional MRI features have limited accuracy in distinguishing septic from aseptic THA failure.
  • Lymph nodal indices, especially those related to node number, show potential as biomarkers for THA infection.
  • Further research into lymph nodal indices could improve diagnostic capabilities for THA infections.

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