title: Will the untreated ulnar styloid fracture influence the outcome of unstable distal radial fracture treated with external fixation when the distal radioulnar joint is stable.
abstract: BACKGROUND
  The ulnar styloid is an important supportive structure for the triangular fibrocartilage complex. However, it remains inconclusive whether or not a fractured ulnar styloid should be fixed in an unstable distal radius fracture (DRF) with a stable distal radioulnar joint (DRUJ). The purpose of this study is to evaluate the effect of an untreated ulnar styloid fracture on the outcome of unstable DRF treated with transarticular external fixation when the DRUJ is stable.
  
  
  METHODS
  106 patients with an unstable DRF and a stable DRUJ were included in this study following external fixation. The patients were divided into the non-fracture, the tip-fracture and the base-fracture groups according to the location of the ulnar styloid fracture at the time of injury. Postoperative evaluation included the range of wrist motion, the radiological index, the grip strength, the PRWE-HK scores, the wrist pain scores, and the instability of DRUJ at the external fixator removal time, three months postoperatively and the final follow-up visit.
  
  
  RESULTS
  The patients were followed for 12 to 24 months (15 months in average). Sixty-two of 106 patients (58%) had ulnar styloid fracture and 16 patients (26%) showed radiographic evidence of union of ulnar styloid fractures at the final follow-up visit. No significant difference in the radiological findings, the range of wrist motion, the grip strength, the PRWE-HK scores, and the wrist pain scores among three patient groups was detected at the external fixator removal time, three months postoperatively, or the final follow-up visit. Six of the 106 patients (5.7%) complained of persistent ulnar-side wrist pain during daily activities. One patient (0.9%) showed a positive sign in a stress-test, three patients (2.8%) showed a positive sign in a provocative-test, and five patients (4.7%) showed a positive sign in a press-test. There was no significant difference in the percentages of patients who complained of persistent ulnar-side wrist pain or showed a positive sign in the physical examination of the distal radioulnar joint among the three groups at the final follow-up time points.
  
  
  CONCLUSIONS
  When the DRUJ is stable, an untreated ulnar styloid fracture does not affect the wrist outcome of the patient with an unstable DRF treated with external fixation.
authors.affiliation: Department of Orthopaedics, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, No. 321 Zhongshan Road, Nanjing, China.
authors.forename: Yi-xin
authors.initials: YX
authors.lastname: Chen
authors.forename: Xin
authors.initials: X
authors.lastname: Zheng
authors.forename: Hong-fei
authors.initials: HF
authors.lastname: Shi
authors.forename: Yu-fan
authors.initials: YF
authors.lastname: Wangyang
authors.forename: Han
authors.initials: H
authors.lastname: Yuan
authors.forename: Xiao-xiao
authors.initials: XX
authors.lastname: Xie
authors.forename: Dong-ya
authors.initials: DY
authors.lastname: Li
authors.forename: Chang-jun
authors.initials: CJ
authors.lastname: Wang
authors.forename: Xu-sheng
authors.initials: XS
authors.lastname: Qiu
mesh_terms: D016267:External Fixators; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000175:diagnosis / Q000209:etiology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009104:Multiple Trauma / Q000628:therapy; D011379:Prognosis; D011885:Radius Fractures / Q000150:complications / Q000175:diagnosis / Q000628:therapy*; D016896:Treatment Outcome; D014458:Ulna Fractures / Q000150:complications / Q000175:diagnosis / Q000628:therapy*; D014955:Wrist Joint / Q000502:physiology*