title: Patellotibial contusions: a rare cruciate ligament injury pattern.
abstract: OBJECTIVE
  Patellotibial contusions are a recently described contusion pattern in anterior cruciate ligament (ACL) tears. The purposes or our study were to determine if patellotibial contusions are specific to ACL injuries, determine the internal derangements in patients demonstrating this contusion, and suggest a mechanism of injury.
  
  
  METHODS
  We conducted a retrospective search of radiology reports over a 6-year period to identify patients with patellar edema described on magnetic resonance (MR) imaging. Only individuals with patellar and tibial edema were included in the study group. These MR examinations were then reviewed for associated internal derangements.
  
  
  RESULTS
  From March 2007 to June 2013, 1914 MR examinations of the knee were performed. Two hundred seventy-one reports described patellar edema. Seven individuals had edema of both the inferior pole of the patella and the anterior tibial plateau. Three individuals were involved in motor vehicle accidents (MVAs); 4 patients had a history of an axial load or sports-related injury. All 3 patients involved in MVAs had posterior cruciate ligament tears consistent with posterior translation of the tibia. The non-MVA individuals had tears of the ACL with internal derangements similar to other ACL deficient knees, however, with more widespread osseous contusions.
  
  
  CONCLUSIONS
  Patellotibial contusions are high-energy injuries resulting in cruciate ligament tears. These contusions occur exclusively in patients with ACL tears when individuals with a history of direct impaction to the knee are excluded. Axial loading of the extended knee may be an important mechanism of injury in these individuals.
authors.affiliation: From the Department of Radiology, 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: Shelia
authors.initials: S
authors.lastname: Boateng
authors.forename: Ariyan
authors.initials: A
authors.lastname: Javadi
authors.forename: Phil
authors.initials: P
authors.lastname: Smith
authors.forename: Seth
authors.initials: S
authors.lastname: Brown
mesh_terms: D000328:Adult; D016118:Anterior Cruciate Ligament / Q000473:pathology; D000070598:Anterior Cruciate Ligament Injuries; D003288:Contusions / Q000150:complications / Q000175:diagnosis* / Q000473:pathology; D004487:Edema / Q000150:complications / Q000175:diagnosis / Q000473:pathology; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000150:complications / Q000175:diagnosis* / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D010329:Patella / Q000293:injuries* / Q000473:pathology; D016119:Posterior Cruciate Ligament / Q000293:injuries* / Q000473:pathology; D012189:Retrospective Studies; D013977:Tibia / Q000293:injuries* / Q000473:pathology