title: The trochlear cleft: initial experience in elite athletes.
abstract: OBJECTIVE
  The trochlear cleft is a recently described vertically oriented, low-signal cartilage lesion centered in the trough of the trochlear cartilage. The purpose of our study was to determine the incidence of clefts in an at-risk group of athletes and correlate these findings with clinical and physical examination results.
  
  
  METHODS
  Sixteen female collegiate volleyball players consented to bilateral knee evaluations, which consisted of history, physical examination, and magnetic resonance (MR) imaging. Two fellowship-trained musculoskeletal radiologists reviewed each MR study by consensus. The trochlear cartilage was considered to be either normal, at risk of developing a cleft, or meeting the previously described criteria for clefts. The Fisher exact test was used for categorical variables, and the Mann-Whitney U test was used for nonparametric continuous variable.
  
  
  RESULTS
  A total of 16 athletes (32 knees; 16 women; age range, 18-22 years; mean, 19.9 years) were enrolled in the study. Four knees (13%) in 3 athletes were diagnosed with a trochlear cleft; 6 knees (19%) in 4 athletes had clefts or were at risk of developing clefts. Among those players with unilateral cartilage lesions, 67% had contralateral abnormalities (P = 0.0783). Functional outcomes and physical examination findings were within normal limits for all athletes, with no difference noted between those with and without clefts.
  
  
  CONCLUSIONS
  Elite athletes have a much higher incidence of trochlear clefts than the general population and are at risk of bilateral disease. Clefts are likely to be an incidental finding at MR imaging for unrelated symptoms.
authors.affiliation: From the Departments of *Radiology and †Orthopaedic Surgery, University of Cincinnati Medical Center, Cincinnati, OH.
authors.forename: Robert D
authors.initials: RD
authors.lastname: Wissman
authors.forename: Eric
authors.initials: E
authors.lastname: England
authors.forename: Kaushal
authors.initials: K
authors.lastname: Mehta
authors.forename: Albert
authors.initials: A
authors.lastname: d'Heurle
authors.forename: Eric
authors.initials: E
authors.lastname: Langenderfer
authors.forename: Robert
authors.initials: R
authors.lastname: Mangine
authors.forename: Keith
authors.initials: K
authors.lastname: Kenter
mesh_terms: D000293:Adolescent; D000328:Adult; D056352:Athletes / Q000706:statistics & numerical data*; D002358:Cartilage, Articular / Q000473:pathology*; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000175:diagnosis* / Q000473:pathology*; D007719:Knee Joint / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D015588:Observer Variation; D054798:Volleyball; D055815:Young Adult