title: What middle phalanx base fracture characteristics are most reliable and useful for surgical decision-making?
abstract: BACKGROUND
  Fracture-dislocations of the proximal interphalangeal joint are vexing because subluxation and articular damage can lead to arthrosis and the treatments are imperfect. Ideally, a surgeon could advise a patient, based on radiographs, when the risk of problems merits operative intervention, but it is unclear if middle phalanx base fracture characteristics are sufficiently reliable to be useful for surgical decision making.
  
  
  OBJECTIVE
  We evaluated (1) the degree of interobserver agreement as a function of fracture characteristics, (2) the differences in interobserver agreement between experienced and less-experienced hand surgeons, and (3) what fracture characteristics and surgeon characteristics were associated with the decision for operative treatment.
  
  
  METHODS
  Ninety-nine (33%) of 296 hand surgeons evaluated 21 intraarticular middle phalanx base fractures on lateral radiographs. Eighty-one surgeons (82%) were in academic practice and 57 (58%) had less than 10 years experience. Participants assessed six fracture characteristics and recommended treatment (nonoperative or operative: extension block pinning, external fixation, open reduction and internal fixation, volar plate arthroplasty, or hemihamate autograft arthroplasty) for all cases.
  
  
  RESULTS
  With all surgeons pooled together, the interobserver agreement for fracture characteristics was substantial for assessment of a 2-mm articular step or gap (kappa, 0.73; 95% CI, 0.60-0.86; p < 0.001), subluxation or dislocation (kappa, 0.72; 95% CI, 0.58-0.86; p < 0.001), and percentage of articular surface involved (intraclass correlation coefficient [ICC], 0.67; 95% CI, 0.54-0.81; p < 0.001); moderate for comminution (kappa, 0.55; 95% CI, 0.39-0.70; p < 0.001) and stability (kappa, 0.54; 95% CI, 0.39-0.69; p < 0.001); and fair for the number of fracture fragments (ICC, 0.39; 95% CI, 0.27-0.57; p < 0.001). When recommending treatment, interobserver agreement was substantial (kappa, 0.69; 95% CI, 0.50-0.88; p < 0.001) for the recommendation to operate or not to operate, but only fair (kappa, 0.34; 95% CI, 0.21-0.47; p < 0.001) for the specific type of treatment, indicating variation in operative techniques. There were no differences in agreement for any of the fracture characteristics or treatment preference between less-experienced and more-experienced surgeons, although statistical power on this comparison was low. None of the surgeon characteristics was associated with the decision for operative treatment, whereas all fracture characteristics were, except for stable and uncertain joint stability. Articular step or gap (β, 0.90; R-squared, 0.89; 95% CI, 0.75-1.05; p < 0.001), likelihood of subluxation or dislocation (β, 0.80; R-squared, 0.76; 95% CI, 0.59-1.02; p < 0.001), and unstable fractures (β, 0.88; R-squared, 0.81; 95% CI, 0.67-1.1; p < 0.001), are most strongly associated with the decision for operative treatment.
  
  
  CONCLUSIONS
  We found that assessment of a step or gap and likelihood of subluxation were most reliable and are strongly associated with the decision for operative treatment. Surgeons largely agree on which fractures might benefit from surgery, and the variation seems to be with the operative technique. Efforts at improving the care of these fractures should focus on the comparative effectiveness of the various operative treatment options.
  
  
  METHODS
  Level III, diagnostic study.
authors.affiliation: Hand and Upper Extremity Service, Department of Orthopaedic Surgery, Yawkey Center, Massachusetts General Hospital, Suite 2100, 55 Fruit Street, Boston, 02114, MA, USA.
authors.forename: Stein J
authors.initials: SJ
authors.lastname: Janssen
authors.affiliation: Hand and Upper Extremity Service, Department of Orthopaedic Surgery, Yawkey Center, Massachusetts General Hospital, Suite 2100, 55 Fruit Street, Boston, 02114, MA, USA.
authors.forename: Jeroen
authors.initials: J
authors.lastname: Molleman
authors.affiliation: Department of Orthopaedic Surgery, Academic Medical Center Amsterdam, Amsterdam, The Netherlands.
authors.forename: Thierry G
authors.initials: TG
authors.lastname: Guitton
authors.affiliation: Hand and Upper Extremity Service, Department of Orthopaedic Surgery, Yawkey Center, Massachusetts General Hospital, Suite 2100, 55 Fruit Street, Boston, 02114, MA, USA. dring@partners.org.
authors.forename: David
authors.initials: D
authors.lastname: Ring
mesh_terms: D001178:Arthroplasty; D064592:Autografts; D016025:Bone Transplantation; D003661:Decision Support Techniques; D005260:Female; D005383:Finger Injuries / Q000000981:diagnostic imaging* / Q000601:surgery*; D005384:Finger Joint / Q000000981:diagnostic imaging* / Q000601:surgery*; D005592:Fracture Fixation / Q000379:methods; D050723:Fractures, Bone / Q000000981:diagnostic imaging* / Q000601:surgery*; D019538:Health Care Surveys; D006801:Humans; D004204:Joint Dislocations / Q000000981:diagnostic imaging* / Q000601:surgery*; D008297:Male; D015588:Observer Variation; D018579:Patient Selection; D010818:Practice Patterns, Physicians'; D011237:Predictive Value of Tests; D011859:Radiography; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires