title: MRI detection of forearm soft tissue injuries with radial head fractures.
abstract: BACKGROUND
  This study aims to evaluate the incidence of forearm soft tissue abnormalities associated with radial head fracture severity based on the Mason classification system.
  
  
  METHODS
  Eighteen patients (age 18-45 years) were prospectively evaluated with elbow radiographs and magnetic resonance imaging (MRI) following longitudinal forearm trauma. MRI was performed within 10 days of the initial injury. Radiographs and MR images were evaluated in a blinded fashion by two musculoskeletal radiologists.
  
  
  RESULTS
  Thirteen of 18 patients presented with Mason type I radial head fractures. In all patients with Mason type I fractures, the interosseous membrane (IOM) was intact. Two patients had Mason type II fractures with associated partial and compete tearing of the IOM and three patients had Mason type III fractures with complete tearing of the IOM. Edema was noted in the pronator quadratus in six of 13 type I injuries and seen in all type II and III injuries. No structural forearm soft tissue abnormalities were present in patients with Mason type I injuries. The presence of edema within the pronator quadratus correlated with distal forearm pain.
  
  
  CONCLUSIONS
  The severity of radial head fracture correlates with longitudinal forearm injury evidenced by the presence of IOM tearing. The findings suggest patients with Mason type II or III fractures of the radial head should undergo further evaluation of the forearm for associated soft tissue injuries. Edema within the pronator quadratus was present following forearm trauma regardless of the severity of fracture and was related to symptomatic forearm pain.
authors.affiliation: Department of Radiology, Stanford University Medical Center, Stanford, CA USA ; McGinley Orthopaedic Innovations, 5910 S Cedar St, Casper, WY 82601 USA.
authors.forename: Joseph C
authors.initials: JC
authors.lastname: McGinley
authors.affiliation: Department of Radiology, Stanford University Medical Center, Stanford, CA USA.
authors.forename: Garry
authors.initials: G
authors.lastname: Gold
authors.affiliation: Department of Orthopaedic Surgery, Stanford University Medical Center, Stanford, CA USA.
authors.forename: Emilie
authors.initials: E
authors.lastname: Cheung
authors.affiliation: Department of Orthopaedic Surgery, Stanford University Medical Center, Stanford, CA USA.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Yao
keywords: Essex-Lopresti lesion; Forearm pain; Interosseous membrane; Longitudinal forearm trauma; Mason classification; Radial head fracture