title: Long-term outcomes for Kienböck's disease.
abstract: BACKGROUND
  The precise etiology of Kienböck's disease is unclear. Controversy exists regarding the appropriate treatment modality. The present study sought to investigate and compare surgical and nonsurgical treatment outcomes of patients suffering from Kienböck's disease in the province of Newfoundland and Labrador (NL), Canada.
  
  
  METHODS
  The present study was a retrospective analysis of 66 patients. The primary outcome was the Disabilities of the Arm, Shoulder, and Hand (DASH) score. Student's t test was used to assess differences in outcomes between treatment groups. One-way ANOVA was used to assess differences in primary outcome in time since first assessed in an effort to examine progression over time. Pearson correlation was used to assess for correlation between primary outcome and age at diagnosis.
  
  
  RESULTS
  The average age was 38.6 ± 11.4 (18-70) years; Four patients were excluded due to inaccessible imaging. Of the remaining patients, 44 were treated conservatively, while 18 were treated surgically. The DASH scores for the surgical group were 23.7 ± 24.5 (0.9-82.8) and nonsurgical group were 20.0 ± 20.1 (1.7-81). As expected, the surgical group was mainly comprised of late-stage Kienböck's. When both groups were compared, there was no significant difference in the DASH scores. There were no difference in DASH scores within groups according to time since first diagnosed (<5 years; between 5 and 10 years; and >10 years). A positive correlation was found between age at diagnosis and DASH score (r = 0.42, p = 0.007), despite treatment modality. This finding remained significant after accounting for confounding factors (p = 0.029).
  
  
  CONCLUSIONS
  The DASH score for the surgical group was 23.7 ± 24.5 (0.9-82.8) and nonsurgical group was 20.0 ± 20.1 (1.7-81). No significant difference in DASH scores was found between surgically and nonsurgically treated patients. A positive association was found between the age at diagnosis of Kienböck's and DASH score, which suggests that patients diagnosed and treated later in life tend not to do as well.
authors.affiliation: Division of Orthopaedic Surgery, Discipline of Surgery, Memorial University, 300 Prince Philip Dr., St. John's, NL Canada A1B 3V6.
authors.forename: Glynn R
authors.initials: GR
authors.lastname: Martin
authors.affiliation: Division of Orthopaedic Surgery, Discipline of Surgery, Memorial University, 300 Prince Philip Dr., St. John's, NL Canada A1B 3V6.
authors.forename: Daniel
authors.initials: D
authors.lastname: Squire
keywords: DASH; Kienböck's disease; Long-term outcomes; Nonsurgical treatment; Surgical treatment