Introduction and An Analysis of Inter- and Intra-observer Validity to the Classification of Hoffa-Like Tibial Plateau Fractures.

Abstract

The posterior coronal shearing fractures of the tibial plateau are rare and can be easily missed or ignored. Our team defined these fractures as Hoffa-like fracture of the tibial plateau and conducted a series of studies. The aim of this study is to introduce the characteristics of the Hoffa-like fracture of the tibial plateau, propose a new classification system and evaluate its validity. Sixty-one patients with Hoffa-like fractures of the tibial plateau were treated in five trauma centers (I-III) from 2017 to 2020. A new classification system was developed based on the morphological fracture patterns in CT and radiographic of the first 30 cases. Ten cases of suspected tibial plateau Hoffa-like fractures were supplemented additionally to the 61 cases to increase the accuracy. CT and radiographic images of the 71 cases were reviewed independently by four reviewers on two separate occasions and classified according to the new classification system. Cohen's kappa coefficient (κ) was used to analyze the reliability on separate observers at the same time and to analyze the classification made by same observer at different times (intra-observer), which measures inter-observer and intra-observer agreements. Out of the 61 patients, 46 (75.4%) isolated coronal fractures involving the medial condyle of tibial plateaus and 53 (86.9%) combined with intercondylar spine fractures. The κ-values were calculated for the new classification system (mean κ = 0.74 inter-observer, mean κ = 0.79 intra-observer, indicating substantial agreement). The novel classification lends insight into fracture morphology of the tibial plateau Hoffa-like fractures, has good inter- and intra-observer validity, and it aids in treatment.