title: A pilot investigation of the prevalence of US-detectable forefoot joint pathology and reported foot-related disability in participants with systemic lupus erythematosus.
abstract: BACKGROUND
  The main aim of this study was to determine the prevalence of US-detectable forefoot bursae, metatarsophalangeal (MTP) joint and metacarpophalangeal (MCP) joint synovial hypertrophy (SH), Power Doppler (PD) signal or erosion in participants with systemic lupus erythematosus (SLE). A secondary aim was to determine the strength of potential association between patient reported foot-related disability and US-detected forefoot bursae, MTP joint SH, PD signal or erosion in participants with SLE.
  
  
  METHODS
  A cross-sectional observational study of 20 participants with SLE was completed to determine the prevalence of US-detected forefoot bursal, MTP and MCP joint pathology. Patient-reported foot-related impairment and activity limitation (accumulatively referred to as disability) were also recorded. Spearmans' Rank Correlation analyses were completed to determine the potential strength of association between US-detected pathology and patient report disability.
  
  
  RESULTS
  The prevalence of MTP joint SH and PD was 80 % (16/20) and 10 % (2/20), respectively. The prevalence of MCP joint SH and PD was 60 % (12/20) and 30 % (6/20) respectively. A significant association was noted between PD scores for the MTP joints and MCP joints (r = 0.556; p = 0.011) although this was not demonstrated for SH scores (r = 0.176; p = 0.459). Significant associations between forefoot bursal prevalence and MTP joint PD were noted (r = 0.467; p = 0.038). The prevalence of bursae and bursal PD (grade 2 or above) was 100 % (20/20) and 10 % (2/20), respectively. Moderate foot-related impairment and activity limitation was reported by 95 and 85 % of participants respectively.
  
  
  CONCLUSIONS
  This pilot study suggests that US-detected MTP, MCP joint and forefoot bursal abnormalities may be prevalent in participants with SLE and they may experience a moderate level of foot-related disability. Further research is required to substantiate these preliminary findings.
authors.affiliation: Faculty of Health Sciences, University of Southampton, Building 45, Burgess Road, Southampton, SO17 1BJ UK.
authors.forename: Sandeep
authors.initials: S
authors.lastname: Mukherjee
authors.affiliation: Faculty of Health Sciences, University of Southampton, Building 45, Burgess Road, Southampton, SO17 1BJ UK.
authors.forename: Lindsey
authors.initials: L
authors.lastname: Cherry
authors.affiliation: Faculty of Health Sciences, University of Southampton, Building 45, Burgess Road, Southampton, SO17 1BJ UK.
authors.forename: Jalaa
authors.initials: J
authors.lastname: Zarroug
authors.affiliation: Faculty of Health Sciences, University of Southampton, Building 45, Burgess Road, Southampton, SO17 1BJ UK.
authors.forename: David
authors.initials: D
authors.lastname: Culliford
authors.affiliation: Faculty of Health Sciences, University of Southampton, Building 45, Burgess Road, Southampton, SO17 1BJ UK.
authors.forename: Catherine
authors.initials: C
authors.lastname: Bowen
authors.affiliation: Faculty of Health Sciences, University of Southampton, Building 45, Burgess Road, Southampton, SO17 1BJ UK.
authors.forename: Nigel
authors.initials: N
authors.lastname: Arden
authors.affiliation: Faculty of Health Sciences, University of Southampton, Building 45, Burgess Road, Southampton, SO17 1BJ UK.
authors.forename: Christopher
authors.initials: C
authors.lastname: Edwards
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D002061:Bursa, Synovial / Q000000981:diagnostic imaging; D004185:Disability Evaluation; D005260:Female; D005534:Foot Diseases / Q000000981:diagnostic imaging* / Q000209:etiology*; D005545:Forefoot, Human / Q000000981:diagnostic imaging; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000150:complications*; D008297:Male; D008662:Metacarpophalangeal Joint / Q000000981:diagnostic imaging; D008683:Metatarsophalangeal Joint / Q000000981:diagnostic imaging; D008875:Middle Aged; D010865:Pilot Projects; D015995:Prevalence; D012720:Severity of Illness Index; D013585:Synovitis / Q000000981:diagnostic imaging / Q000209:etiology; D018608:Ultrasonography, Doppler / Q000379:methods
keywords: Bursa; Forefoot; Human; Joints; Lupus erythematosus; Synovial; Systemic; Ultrasonography