Are methods to quantify osseous exposure in orthopedic surgery reliable?

Our study examined if there were any limitations when using various measurement techniques in the literature to quantify osseous exposure. Additionally, we also examined if surface contour had any influence on obtained measurements, which no previous study has attempted.

Three methods used to quantify osseous exposure area were identified, one in which involves manually applying mesh over exposure area. The other two use digital image capture software (ImageJ, Bethesda, MD). We simulated flat, convex, and mixed surface types using synthetic bone analogs. We assessed the degree of variability between mean values using an ANOVA or Kruskal-Wallis equality of populations rank test. Cronbach's alpha test of internal reliability was used to assess the internal reliability of measurement technique.

ANOVA test for difference in measurement techniques on all three surface types was statistically significant (p < 0.05). Cronbach's alpha test of internal reliability for each technique on the convex surface did not obtain adequate significance (alpha >0.70). Only the mesh method obtained adequate alpha value for significance when applied to the flat and mixed surface types.

Each of the three measurement techniques tested demonstrated poor internal reliability. We suggest taking care when comparing studies that use different quantification techniques when calculating osseous exposure for different surgical approaches. Future studies should explore alternative methods of osseous exposure quantification.