title: The feet in systemic lupus erythematosus; are we underestimating their involvement and functional impact?
abstract: OBJECTIVE
  To evaluate biomechanical and ultrasound (US) abnormalities in SLE patients as compared with controls and to assess the relationship between these abnormalities and SLE activity.
  
  
  METHODS
  Fifty-four consecutive female patients with SLE with and without foot pain and 60 female controls (30 with foot pain and 30 without foot pain) were recruited. SLE activity was assessed by the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). SLE patients and controls blindly underwent a comprehensive podiatric, biomechanical and US evaluation of the feet. US assessment included detection of B-mode synovitis, tenosynovitis, enthesopathy, bone changes and synovial, tenosynovial and entheseal power Doppler (PD) signal.
  
  
  RESULTS
  Thirty-one (57.4%) SLE patients had bilateral foot pain and 5 (9.3%) had unilateral foot pain. Metatarsalgia was the most common location for pain but without significant difference between groups (p=0.284). Toe joint deformities were significantly more common in SLE feet as compared with control feet (p<0.0005). SLE feet showed significantly more biomechanical abnormalities than control feet (p<0.05). B-mode synovitis in the tibiotalar joint was strongly associated with having SLE (p<0.0005) and the presence of synovial PD signal in the MTP joints was found only in painful feet of SLE patients. SLEDAI was significantly higher in patients with foot pain than in those with painless feet (p=0.008). However, SLEDAI did not discriminate between patients with and without biomechanical or US abnormalities.
  
  
  CONCLUSIONS
  SLE patients showed more biomechanical and US abnormalities in the feet than controls, which were not captured by standardised assessment of the disease activity.
authors.affiliation: University Podiatry Clinic, Faculty of E.F.Podiatry Universidad Complutense de Madrid, Spain.
authors.forename: Rosario
authors.initials: R
authors.lastname: Morales-Lozano
authors.affiliation: Department of Rheumatology, Hospital General Universitario Gregorio Marañón, Madrid, Spain. juliamartinezbarrio@gmail.com.
authors.forename: Julia
authors.initials: J
authors.lastname: Martínez-Barrio
authors.affiliation: University Podiatry Clinic, Faculty of E.F.Podiatry Universidad Complutense de Madrid, Spain.
authors.forename: María Luz
authors.initials: ML
authors.lastname: González-Fernández
authors.affiliation: Department of Rheumatology, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: López-Longo
authors.affiliation: Department of Rheumatology, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: Juan Gabriel
authors.initials: JG
authors.lastname: Ovalles-Bonilla
authors.affiliation: Department of Rheumatology, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: Lara
authors.initials: L
authors.lastname: Valor
authors.affiliation: Department of Rheumatology, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: Iustina
authors.initials: I
authors.lastname: Janta
authors.affiliation: Department of Rheumatology, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Nieto
authors.affiliation: Department of Rheumatology, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: Diana
authors.initials: D
authors.lastname: Hernández-Flórez
authors.affiliation: Department of Rheumatology, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: Carlos M
authors.initials: CM
authors.lastname: González
authors.affiliation: Department of Rheumatology, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: Indalecio
authors.initials: I
authors.lastname: Monteagudo
authors.affiliation: Department of Social Psychology and Methodology, Universidad Autónoma de Madrid, Spain.
authors.forename: Jesús
authors.initials: J
authors.lastname: Garrido
authors.affiliation: Department of Rheumatology, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Carreño
authors.affiliation: Department of Rheumatology, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: Esperanza
authors.initials: E
authors.lastname: Naredo
mesh_terms: D001323:Autoantibodies / Q000097:blood; D015415:Biomarkers / Q000097:blood; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D005528:Foot / Q000000981:diagnostic imaging / Q000503:physiopathology; D005531:Foot Deformities, Acquired / Q000097:blood / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000150:complications* / Q000175:diagnosis; D010146:Pain / Q000097:blood / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D010147:Pain Measurement; D011032:Podiatry / Q000379:methods; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D012720:Severity of Illness Index; D018608:Ultrasonography, Doppler
chemical_list: D001323:Autoantibodies; D015415:Biomarkers