title: Relationship between tibial spine size and the occurrence of osteochondritis dissecans: an argument in favour of the impingement theory.
abstract: OBJECTIVE
  Pathophysiology of osteochondritis dissecans (OCD) of the medial femoral condyle remains uncertain. Specifically, the relationship between the size of the anterior tibial spine (ATS) and the presence of OCD has not been explored. The purpose of this study was to evaluate the relationship between ATS size and the occurrence of OCD.
  
  
  METHODS
  Seventy-nine children between 8 and 17 years of age were included in two groups: OCD (n = 37) and control (n = 42). The groups were matched in terms of age, gender, BMI and weight. Two independent observers performed an MRI analysis of the size of the tibial spine and intercondylar notch relative to the size of the respective epiphyses. For this study, the "S ratio" was calculated by dividing the height of the tibial spine by the height of the tibial epiphysis. The "N ratio" was calculated by dividing the height of the notch by the height of the femoral epiphysis. These two ratios for both groups were compared using Student's t test.
  
  
  RESULTS
  The mean value of the S ratio in the OCD group was 0.39 ± 0.06; the mean value of the S ratio in the control group was 0.32 ± 0.03 (P = 0.004). The mean value of the N ratio in the OCD group was 0.70 ± 0.08; the mean value of the N ratio in the control group was 0.70 ± 0.07 (n.s.).
  
  
  CONCLUSIONS
  This study's findings confirm our hypothesis that patients with OCD have a more prominent tibial spine than in patients without OCD.
  
  
  METHODS
  IV.
authors.affiliation: Musculoskeletal Institute, Hôpital Pierre Paul Riquet, CHU Toulouse Purpan, 1 place Baylac, 31000, Toulouse, France. cavaignac.etienne@gmail.com.
authors.forename: Etienne
authors.initials: E
authors.lastname: Cavaignac
authors.affiliation: Pediatric Radiology Department, Hôpital des enfants, CHU Toulouse, Toulouse, France.
authors.forename: Geoffroy
authors.initials: G
authors.lastname: Perroncel
authors.affiliation: Pediatric Orthopedic Surgery Department, Hôpital des enfants, CHU Toulouse, Toulouse, France.
authors.forename: Mathias
authors.initials: M
authors.lastname: Thépaut
authors.affiliation: Pediatric Radiology Department, Hôpital des enfants, CHU Toulouse, Toulouse, France.
authors.forename: Julie
authors.initials: J
authors.lastname: Vial
authors.affiliation: Pediatric Orthopedic Surgery Department, Hôpital des enfants, CHU Toulouse, Toulouse, France.
authors.forename: Franck
authors.initials: F
authors.lastname: Accadbled
authors.affiliation: Pediatric Orthopedic Surgery Department, Hôpital des enfants, CHU Toulouse, Toulouse, France.
authors.forename: Jérôme Sales
authors.initials: JS
authors.lastname: De Gauzy
mesh_terms: D000293:Adolescent; D001175:Arthrography; D002648:Child; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D008297:Male; D010008:Osteochondritis Dissecans / Q000000981:diagnostic imaging* / Q000503:physiopathology; D013977:Tibia / Q000000981:diagnostic imaging* / Q000473:pathology
keywords: Impingement; Knee; Medial tibial spine; Osteochondritis dissecans