Comparison of two kinds of fractures involving posterior malleolar fracture

Abstract

To investigate the difference between the spiral tibial shaft fracture combined with ipsilateral posterior malleolar fracture.(TSPMF) and simple ipsilateral posterior malleolar fracture in ankle joint fracture in adults. The sex, age, and type and mechanism of fracture of 82 patients with tibial shaft fracture associated with ankle joint fracture (TAF) and 28 patients with tibial shaft spiral fracture associated with ipsilateral posterior malleolar fracture (TSPMF) among 1685 cases of adult tibial and fibular shaft fracture and 330 patients with posterior malleolar fracture among 1871 cases of simple ankle joint fracture were analyzed. The mean age of the 28 cases with TSPMF, 24 males and 4 females, was (41.1 +/- 11.8). The mean age of the 330 cases with simple posterior malleolar fracture, 187 males and 143 females, was (42.6 +/- 15.9). The incidence of posterior malleolar fracture in the TAF patients was 34.1% (28/82), significantly higher than that of the simple ankle joint fracture [17.6%, 330/1871, P = 0.000]. The rate of combined external malleolus and posterior malleolus in the TSPMF patients was 17.9% (5/28), significantly that in the patients with simple ankle joint fracture (73.7%, 159/330, P = 0.000). The fibular fracture line of 75.0% (21/28) of the TSPMF patients was located over the level of the lower tibiofibular ligament union, a rate significantly higher than that in the simple malleolus fracture (24.8%, 82/330, P = 0.000). Spiral tibial shaft fracture associated with ipsilateral posterior malleolar fracture is a special kind of fracture; the cause and mechanism of TSPMF are difference from those of the ankle joint fracture.