Incidence and surgical fixation-related factors of posterior malleolus fracture in treatment of ankle fractures

Abstract

Objective To investigate the incidence and surgical fixation-related factors of posterior malleolus fracture in the treatment of ankle fractures. Methods A retrospective study was conducted of the 703 inpatients with ankle fracture at Department of Foot and Ankle Surgery, Beijing Jishuitan Hospital from June 1, 2017 to May 31, 2018. Of them, 464 suffered posterior malleolus fracture. The incidence and surgical fixation rate of posterior malleolar fracture were calculated. Of the patients with posterior malleolus fracture, the gender, age, injury energy, Lauge-Hanse classification, Bartonicek classification, talar backward subluxation, fragment area ratio (FAR) of posterior malleolus fracture on X-ray film and CT cross section, fragmental dislocation, and Die-punch fragment were analyzed to screen out the risk factors related to surgical internal fixation for posterior malleolus fracture. Results In this study, the incidence of posterior malleolus fracture was 66.00% (464/703) and the surgical fixation rate 43.97% (204/464). The gender, age, injury energy, Lauge-Hanse classification, direction of talar subluxation and displacement of Die-punch fragments were not the risk factors related to the surgical internal fixation for posterior malleolus fracture (P>0.05) while the Bartonicek classification, talar backward subluxation, FAR of posterior malleolus fracture on X-ray film and CT cross section, lateral fragmental displacement and Die-punch fragment were the risk factors related to the surgical internal fixation for posterior malleolus fracture (P<0.05). Logistic regression analysis indicated that the talar backward subluxation (OR=5.580, 95% CI:1.623~19.181, P=0.006) and the FAR ≥15% on CT cross section (OR=9.103, 95% CI: 3.342~24.800, P=0.000) were independent risk factors for surgical internal fixation of posterior malleolus fracture. Conclusions The incidence and surgical fixation rate of posterior malleolar fracture are very high. The talar backward subluxation and the fragment area ratio ≥15% on CT cross-section are independent risk factors for surgical internal fixation of posterior malleolus fracture. Key words: Ankle; Posterior malleolus; Fractures, bone; Fracture fixation; Related factors