Coronal shear fractures of the capitellum and trochlea: interobserver variability in classifying the fracture and the need for a computed tomography scan for the correct surgical planning

Abstract

Background To determine interobserver agreement in the classification by X-rays and by computed tomography (CT) scan of the coronal shear fractures of the capitellum and trochlea as well as the agreement between these two tests. Methods Patients with coronal shear fractures of the capitellum who were managed at our center between January 2008 and December 2017 were included. This retrospective cohort study was carried out with the approval of the ethics committee of our institution (Nº: IIBSP-Cod-2019-02, Ref. 19/070). Clinical, radiographic, and elbow-specific outcomes, including the Mayo Elbow Performance Index, were evaluated. Three observers analyzed the preoperative X-rays from all the cases. Each one of them independently classified the fractures according to the Bryan and Morrey classification (with the modification of McKee et al). The interobserver agreement was calculated by Cohen kappa coefficient. The same methodology was used to analyze the CT scan. Thereafter, one single value was determined for each X-ray and CT scan, from the good interobserver agreements. Finally, the agreement between the global X-ray classification and the global CT scan classification was calculated using the agreement percentage and the Cohen kappa coefficient. Results There were 3 males and 6 females, with a mean age of 47 years (range, 18-83). The mean follow-up period was 18 months (12-40). The average Mayo Elbow Performance Index score was 85 (range, 65-100) points. The complications were nonunion in one patient (11 %), degenerative arthritis in 7 (78 %), joint step-off in 5 (55%), and heterotopic ossification in 7 (78%). The agreement analysis between the global X-ray classification and the global CT scan classification showed a 57.1% agreement, with a kappa coefficient of −0.167. These values imply the absence of agreement. Conclusion Our results demostrated that simple X-rays do not allow for the adequate interpretation of distal humeral coronal plane fractures. Although an acceptable interobserver agreement was found, there is no agreement when the same fractures were analyzed by CT scan. The authors routinely recommend CT scan to assess the extent of the fracture and perform surgical planning.

Open reduction and internal fixation by hollow screw for capitellum fractures in children

“…CT and three-dimensional reconstruction examination of elbow joint can help to de ne the fracture range and the displacement direction of bone mass, which is of great signi cance for the diagnosis and classi cation of fracture and can guide the follow-up treatment. Therefore, these examinations should be conducted before surgery [13]. Bryan-Morrey classi cation of capitellum fractures are commonly used in clinical practice.…”

Coronal Shear Fractures of the Distal Humerus

“…A computed tomography (CT) scan with 3D reconstructions is very helpful for assessment of these patients [ 23 ]. CT allows for the precise evaluation of the posterior capitellum and medial trochlea.…”

Humeral Capitellum Fractures in Adolescents: A Study of 6 Cases Treated by Open Reduction and Internal Fixation with Bioabsorbable Nails

“…The symptom of a double arch is described in the literature, which is typical for type IV fractures according to the Bryan and Morrey classification [ 8 ]. CT scan is crucial for the correct diagnosis [ 14 ]. The typical clinical symptoms include swelling, pain, and limited active and passive elbow motions.…”