title: A clinical classification system for rheumatoid forefoot deformity.
abstract: OBJECTIVE
  In the present study a classification system for the rheumatoid forefoot is reported with its intra- and interobserver reliability and clinical relevance. The classification is based on the sequence of anatomical changes resulting from the loss of integrity of the MTP joints, loss of motion and changes regarding the quality and position of the plantar soft tissues. It is hypothesized that with progression of the amount of deformity of the MTP joint(s), patients have more pain and functional loss.
  
  
  METHODS
  In total 94 patients were included in the study following precise inclusion criteria. The forefeet of the patients were classified according to the introduced classification system by two observers in order to determine the intra- and interobserver reliability. The relation of the suggested classification between pain, function scores, and plantar foot pressure measurements was examined.
  
  
  CONCLUSIONS
  According to the Cohen's kappa and the ICC, the intra- and inter-observer reliability were high. Despite the large variation between subjects in a certain grade, a clear trend was found between increase in classification and VAS for pain, FFI difficulty with activities, and plantar peak pressure under the metatarsals. The suggested classification is of clinical relevance and can be used to develop therapeutical algorithms and to test interventions.
authors.affiliation: Department of Orthopedic Surgery, Medical Center Leeuwarden, The Netherlands.
authors.forename: Peter F
authors.initials: PF
authors.lastname: Doorn
authors.forename: Noël L W
authors.initials: NL
authors.lastname: Keijsers
authors.forename: Jacques
authors.initials: J
authors.lastname: van Limbeek
authors.forename: Patricia G
authors.initials: PG
authors.lastname: Anderson
authors.forename: Roland F J M
authors.initials: RF
authors.lastname: Laan
authors.forename: Paul Van't Pad
authors.initials: PV
authors.lastname: Bosch
authors.forename: Maarten C de Waal
authors.initials: MC
authors.lastname: Malefijt
authors.forename: Jan Willem K
authors.initials: JW
authors.lastname: Louwerens
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000150:complications*; D005260:Female; D005531:Foot Deformities, Acquired / Q000145:classification* / Q000209:etiology*; D005545:Forefoot, Human / Q000002:abnormalities*; D006801:Humans; D008297:Male; D008875:Middle Aged