Comparison of Expert Opinion, Majority Rule, and a Clinical Prediction Rule to Estimate Distal Radius Malalignment.

OBJECTIVES

To investigate the ability of individual surgeons [expert opinion (EO)] to predict distal radius fracture (DRF) healing above a threshold malalignment compared with the majority prediction of the group of surgeons ["majority rule," (MR)] and a statistically derived clinical prediction formula [Edinburgh wrist calculator (EWC)].

DESIGN

Comparative diagnostic study from prospectively collected data of consecutive patients.

SETTING

Two academic level 1 and 1 academic level 2 trauma centers.

PATIENTS/

PARTICIPANTS

Eighteen surgeons assessed probability of healing above a threshold malalignment (often referred to as fracture "instability") for 71 fractures based on radiographs taken initially and after closed reduction and cast application. The probability of losing alignment according to the EWC was dichotomized (likely to lose alignment ≥0.5 vs. unlikely <0.5).

MAIN OUTCOME MEASURES: Accuracy parameters of prediction of EO, MR, and EWC.

RESULTS

EWC and MR demonstrated higher accuracy (0.77 and 0.75, respectively) and sensitivity (0.95 and 0.79, respectively) compared with EO (accuracy, 0.66 and sensitivity, 0.58) for predicting healing above the threshold malalignment. Reliability was higher for MR (kappa 0.88) than for EWC (kappa 0.63) or EO (kappa coefficient 0.44). The negative predictive value of the EWC for healing above a threshold of malalignment was excellent (0.97).

CONCLUSIONS

Surgeon opinion is not reliable or accurate for predicting loss of alignment of a DRF above a threshold malalignment after closed reduction and immobilization. Dichotomized EWC may be a useful tool in predicting loss of alignment (instability) of a DRF.

LEVEL OF EVIDENCE: Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.