title: Comparisons of three radiographic views in assessing for scapholunate instability.
abstract: BACKGROUND
  Multiple wrist x-ray images have been described to assess for scapholunate (SL) instability. Some views may be redundant. The purpose of this study was to compare three plain x-ray views in identifying a traumatic diastasis of the SL interval.
  
  
  METHODS
  Nineteen patients (19 wrists) with a positive scaphoid shift test and surgically confirmed SL ligament damage were identified. There were 15 males and 4 females with a mean age of 39 years. Pre-operative x-rays were reviewed, including posteroanterior (PA) neutral and PA ulnar deviation views of the injured wrist, and PA clenched fist views of the injured and uninjured wrists. Dynamic SL instability was defined by an SL mid-interval gap of <3 mm and static SL instability by a gap of ≥3 mm in the PA neutral views. The mid-interval measurements were compared between x-ray images.
  
  
  RESULTS
  There were 10 dynamic and 9 static SL instability cases. The PA ulnar deviation and the PA clenched fist views showed significantly greater SL gaps in comparison to the PA neutral views in dynamic but not static SL instability cases. In both categories of instability, there was no significant difference in the SL gaps between the two stress images. The PA clenched fist view of the uninjured wrist revealed SL gapping of >3 mm in 50% of patients but with generally greater gapping in the clenched fist view of the injured wrist.
  
  
  CONCLUSIONS
  The PA ulnar deviation and clenched fist stress views were equally effective in showing a dynamic SL diastasis following wrist injury. Neither view was more effective than a neutral PA view in diagnosing static SL instability.
authors.affiliation: Department of Orthopaedic Surgery, Northwestern University Feinberg School of Medicine, 676 N. St. Clair, Suite 1350, Chicago, IL 60611 USA.
authors.forename: Ronak M
authors.initials: RM
authors.lastname: Patel
authors.affiliation: Department of Orthopaedic Surgery, Northwestern University Feinberg School of Medicine, 676 N. St. Clair, Suite 1350, Chicago, IL 60611 USA ; Northwestern Center for Surgery of the Hand, 737 N. Michigan Ave., Suite 700, Chicago, IL 60611 USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Kalainov
authors.affiliation: Department of Orthopaedic Surgery, Northwestern University Feinberg School of Medicine, 676 N. St. Clair, Suite 1350, Chicago, IL 60611 USA.
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Chilelli
authors.affiliation: Cadence Physician Group Orthopaedics, 27650 Ferry Road, Suite 100, Warrenville, IL 60555 USA.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Makowiec
keywords: Carpal instability; Scapholunate instability; Wrist radiography