Three-dimensional measurement of articular surface injury severity due to posterior malleolus fracture / 中华创伤杂志

ABSTRACT

Objective To establish a way to measure the injury severity of articular surface due to posterior malleolus fracture and investigate its clinical significance based on three-dimensional reconstruction technique.Methods Between May 2009 and March 2014,138 cases of peri-ankle injury combined with posterior malleolus fracture were treated.Lateral radiographs were reviewed to measure the ratio of posterior fragment area to distal tibial plafond area using the common method.Three-dimensional CT images were examined to measure ratio of the area of injury using the three-dimensional measuring method.Statistical comparison was made using the t-test and intraclass correlation coefficient (ICC).Results Measurement failed on 33 lateral radiographs and 13 three-dimensional CT images.Six cases cannot be measured by both imaging technology,so results of 98 cases were compared.Ratio of posterior fragment area to tibial plafond area was (16.2 ± 7.2) ％ measured by radiographs and was (29.6 ±10.1) ％ by three-dimensional CT scans (P ＜ 0.05).Three-dimensional CT measurements showed higher intra and inter-observer agreement (ICC of 0.973 to 0.942) than that in radiographic measurements (ICC of 0.875 to 0.860).Conclusion Three-dimension CT assessment of the extent of injury to articular surface because of posterior malleolus fracture is reliable and reproducible,but radiographic assessment may underestimate the injury and influence the choice of surgical indications.