The Significance of Evaluating the Femoral Head Blood Supply after Femoral Neck Fracture: A New Classification for Femoral Neck Fractures

Abstract

Objective: To compare a new classification with the Garden classification by exploring their relationships with vascular injury.

Methods: This retrospective study enrolled 73 patients with subcapital femoral neck fracture from July 2015 to November 2018, including 32 males and 41 females with an average age of 47.2 years. All patients were classified by the Garden classification using anteroposterior X-ray imaging and by a new classification system based on three-dimensional CT imaging. The blood supply of the affected femoral head in these patients was evaluated based on DSA images. Correlations between the two classifications and the degree of vascular injury were assessed.

Results: The results of the DSA examination indicated that eight patients had no retinacular vessel injury, 20 patients had one retinacular vessel injury, 35 patients had two retinacular vessel injuries, and 10 patients had three retinacular vessel injuries. The degree of vascular injury was used to match the two fracture classifications. Forty-nine Garden classifications (Type I-IV: 8, 12, 23, 6, respectively, 67.12%) and 66 new classifications (Type I-IV: 8, 20, 32, 6, respectively, 90.41%) corresponded to the degree of vascular injury (p < 0.05). The Garden classification showed moderate reliability, and the new classification showed near perfect agreement (Interobserver agreement of k = 0.564 [0.01] in Garden classification vs. Garden classification k = 0.902 [0.01] for the five observers).

Conclusions: The new classification system can accurately describe the degree of fracture displacement and judge the extent of vascular injury.

Keywords: classification; digital substraction angiography; femeral neck fracture; retinacular vessel; three-dimensional CT.