title: Can deformity of the knee and longitudinal growth of the leg be predicted in patients with hereditary multiple exostoses? A cross-sectional study.
abstract: BACKGROUND
  There is a high rate of knee deformity in patients with hereditary multiple exostoses (HME), and a quarter of patients have a limb length discrepancy.
  
  
  METHODS
  A prospective database of 172 patients with HME was compiled. Patient demographics, knee deformity and range of movement, leg length and height, and number of exostoses around the knee were recorded.
  
  
  RESULTS
  Nine out of 10 patients with HME were affected by exostoses around the knee, of which the distal femur was the most common site to be involved. Approximately 20% of patients had a valgus deformity and 16% had a fixed flexion deformity of the knee, with 25% having a diminished range of movement. Height was directly proportional to leg length and a quarter of patients were below the 10th centile for height. The presence of a distal femoral exostosis was an independent predictor of knee deformity (p=0.002), diminished range of movement (ROM) (p<0.001), and smaller stature (p<0.001) on multivariate analysis. In addition increasing age, prior surgery, genotype, and gender were also intendant predictors of ROM and height.
  
  
  CONCLUSIONS
  Future studies analysing if surgical excision improves knee function and limits deformity would need to assess whether this is dependent upon anatomical site, as our results suggest that distal femoral exostoses may have the greatest affect upon these outcomes.
  
  
  METHODS
  Level II.
authors.affiliation: Department of Orthopaedics and Trauma, The Royal Infirmary of Edinburgh, Little France, Edinburgh, EH16 4SA, UK. Electronic address: nickclement@doctors.org.uk.
authors.forename: N D
authors.initials: ND
authors.lastname: Clement
authors.affiliation: Department of Orthopaedics and Trauma, The Royal Infirmary of Edinburgh, Little France, Edinburgh, EH16 4SA, UK.
authors.forename: D E
authors.initials: DE
authors.lastname: Porter
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001827:Body Height / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005097:Exostoses, Multiple Hereditary / Q000000981:diagnostic imaging / Q000235:genetics / Q000503:physiopathology*; D005260:Female; D005269:Femur / Q000002:abnormalities / Q000000981:diagnostic imaging / Q000503:physiopathology; D005838:Genotype; D006801:Humans; D016916:Joint Deformities, Acquired / Q000145:classification / Q000000981:diagnostic imaging / Q000503:physiopathology*; D007719:Knee Joint / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000503:physiopathology; D007870:Leg Length Inequality / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011446:Prospective Studies; D011859:Radiography; D016059:Range of Motion, Articular / Q000502:physiology; D012737:Sex Factors; D055815:Young Adult