Reliability of the classification of proximal femur fractures: Does clinical experience matter?

BACKGROUND

Radiographic fracture classification helps with research on prognosis and treatment. AO/OTA classification into fracture type has shown to be reliable, but further classification of fractures into subgroups reduces the interobserver agreement and takes a considerable amount of practice and experience in order to master.

QUESTIONS/PURPOSES

We assessed: (1) differences between more and less experienced trauma surgeons based on hip fractures treated per year, years of experience, and the percentage of their time dedicated to trauma, (2) differences in the interobserver agreement between classification into fracture type, group, and subgroup, and (3) differences in the interobserver agreement when assessing fracture stability compared to classifying fractures into type, group and subgroup.

METHODS

This study used the Science of Variation Group to measure factors associated with variation in interobserver agreement on classification of proximal femur fractures according to the AO/OTA classification on radiographs. We selected 30 anteroposterior radiographs from 1061 patients aged 55 years or older with an isolated fracture of the proximal femur, with a spectrum of fracture types proportional to the full database. To measure the interobserver agreement the Fleiss' kappa was determined and bootstrapping (resamples = 1000) was used to calculate the standard error, z statistic, and 95% confidence intervals. We compared the Kappa values of surgeons with more experience to less experienced surgeons.

RESULTS

There were no statistically significant differences in the Kappa values on each classification level (type, group, subgroup) between more and less experienced surgeons. When all surgeons were combined into one group, the interobserver reliability was the greatest for classifying the fractures into type (kappa, 0.90; 95% CI, 0.83 to 0.97; p < 0.001), reflecting almost perfect agreement. When comparing the kappa values between classes (type, group, subgroup), we found statistically significant differences between each class. Substantial agreement was found in the clinically relevant groups stable/unstable trochanteric, displaced/non-displaced femoral neck, and femoral head fractures (kappa, 0.60; 95% CI, 0.53 to 0.67, p < 0.001).

CONCLUSIONS

This study adds to a growing body of evidence that relatively simple distinctions are more reliable and that this is independent of surgeon experience.

The Effect of Price on Surgeons' Choice of Implants: A Randomized Controlled Survey

PURPOSE

Surgical costs are under scrutiny and surgeons are being held increasingly responsible for cost containment. In some instances, implants are the largest component of total procedure cost, yet previous studies reveal that surgeons' knowledge of implant prices is poor. Our study aims to (1) understand drivers behind implant selection and (2) assess whether educating surgeons about implant costs affects implant selection.

METHODS

We surveyed 226 orthopedic surgeons across 6 continents. The survey presented 8 clinical cases of upper extremity fractures with history, radiographs, and implant options. Surgeons were randomized to receive either a version with each implant's average selling price ("price-aware" group), or a version without prices ("price-naïve" group). Surgeons selected a surgical implant and ranked factors affecting implant choice. Descriptive statistics and univariate, multivariable, and subgroup analyses were performed.

RESULTS

For cases offering implants within the same class (eg, volar locking plates), price-awareness reduced implant cost by 9% to 11%. When offered different models of distal radius volar locking plates, 25% of price-naïve surgeons selected the most expensive plate compared with only 7% of price-aware surgeons. For cases offering different classes of implants (eg, plate vs external fixator), there was no difference in implant choice between price-aware and price-naïve surgeons. Familiarity with the implant was the most common reason for choosing an implant in both groups (35% vs 46%). Price-aware surgeons were more likely to rank cost as a factor (29% vs 21%).

CONCLUSIONS

Price awareness significantly influences surgeons' choice of a specific model within the same implant class. Merely including prices with a list of implants leads surgeons to select less expensive implants. This implies that an untapped opportunity exists to reduce surgical expenditures simply by enhancing surgeons' cost awareness.

TYPE OF STUDY/LEVEL OF EVIDENCE

Economic/Decision Analyses I.