Maisonneuve fracture is a special type of ankle fracture that consists of proximal fibular fracture, a lesion of the inferior tibiofibular syndesmotic complex (interosseous ligament, anterior inferior tibiofibular ligament and posterior inferior tibiofibular ligament), and injury of the medial structure of the ankle (deltoid ligament tear or medial malleolar fracture). The accepted mechanism of Maisonneuve fracture is pronation external rotation according to the Lauge-Hansen classification. In this paper, we report a rare pattern of Maisonneuve fracture, which has the characteristics of both pronation external rotation ankle fracture and supination adduction ankle fracture.

A 31-year-old female patient accidentally sprained her right ankle while walking 5 d before hospitalization in our hospital. The patient was initially missed in other hospitals and later rediagnosed in our outpatient department. Full-length radiographs of the lower leg revealed proximal fibula fracture, inferior tibiofibular joint separation, and medial malleolar fracture involving the posterior malleolus, which was also revealed on computed tomography scans. Magnetic resonance imaging revealed rupture of the anterior inferior tibiofibular ligament and anterior talofibular ligament. We diagnosed a rare pattern of Maisonneuve fracture with proximal fibular fracture, inferior tibiofibular joint separation, medial malleolar fracture and ruptures of the anterior inferior tibiofibular ligament and anterior talofibular ligament. The patient underwent open reduction and internal fixation in our hospital. A 6-mo postoperative follow-up confirmed a good clinical outcome.

To our knowledge, this rare pattern of Maisonneuve fracture has not been previously described. The possible mechanism of injury is supination adduction combined with pronation external rotation. Careful analysis of the injury mechanism of Maisonneuve fracture is of great clinical significance and can better guide clinical treatment.

There is sparse information in the literature on the outcome of Maisonneuve-type pronation-external rotation ankle fractures treated with syndesmotic screws. The primary aim of this study was to determine the long-term results of such treatment of these fractures as indicated by standardized patient-based and physician-based outcome measures. The secondary aim was to identify predictors of the outcome with use of bivariate and multivariate statistical analysis.

Fifty patients with pronation-external rotation (predominantly Maisonneuve) fractures were treated with open reduction and internal fixation of the syndesmosis utilizing only one or two screws. The results were evaluated at a mean of twenty-one years after the fracture utilizing three standardized outcomes instruments: (1) the Foot and Ankle Ability Measure (FAAM), (2) the American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scale, and (3) the Center for Epidemiologic Studies-Depression (CES-D) Scale. Osteoarthritis was graded according to the van Dijk and revised Takakura radiographic scoring systems. Bivariate and multivariate analyses were performed to identify predictors of long-term outcome.

Forty-four (92%) of forty-eighty patients had good or excellent AOFAS scores, and forty-four (90%) of forty-nine had good or excellent FAAM scores. Arthrodesis for severe osteoarthritis was performed in two patients. Radiographic evidence of osteoarthritis was observed in twenty-four (49%) of forty-nine patients. Multivariate analysis identified pain as the most important independent predictor of long-term ankle function as indicated by the AOFAS and FAAM scores, explaining 91% and 53% of the variation in scores, respectively. Analysis of pain as the dependent variable in bivariate analyses revealed that depression, ankle range of motion, and a subsequent surgery were significantly correlated with higher pain scores. No firm conclusions could be drawn after multivariate analysis of predictors of pain.

Long-term functional outcomes at a mean of twenty-one years after pronation-external rotation ankle fractures treated with one or two syndesmotic screws were good to excellent in the great majority of patients despite substantial radiographic evidence of osteoarthritis in one-half of the patients. The most important predictor of long-term functional outcome was patient-reported pain rather than physician-reported function or posttraumatic osteoarthritis. There was no significant association between radiographic signs of posttraumatic osteoarthritis and perceived pain in the present series.