Prevalence and Risk Factors of Concomitant Malleolar and Fibular Fractures in Distal Spiral Tibial Shaft Fractures

Abstract Purpose: (1) To evaluate the incidence and morphology features of concomitant malleolar and fibular fractures in patients with distal spiral tibial shaft fractures. (2) To evaluate the risk factors for concomitant malleolar fractures in patients with distal spiral tibial shaft fractures. Methods: A retrospective review was performed on 64 cases of operatively treated distal spiral tibial shaft fractures with complete radiographs and computed tomography (CT) scans. Data were collected on age, sex, injured side, AO classification of tibial shaft fractures, relative fibular fracture location, patterns and severity of concomitant malleolar fractures. Univariate analysis was performed to analyze factors associated with concomitant malleolar fractures. Results: The incidence of concomitant malleolar fractures in distal spiral tibial shaft fractures found in this study was 89.1%, including 50% of single fracture and 39.1% of multiple fractures. The most frequent being posterior malleolar fractures (PMF), followed by anterior inferior tibiofibular ligament (AITFL) avulsion fractures and lateral malleolar fractures (LMF). 58 cases (90.6%) had concomitant fibula fractures, with the most common location being proximal to the tibial fracture. There was a significant association between AO42B fractures and fibular fractures at the same level as the tibia. Age was associated with the severity of concomitant malleolar fractures (p=0.422), particularly with AITFL avulsion fractures (p=0.0251) and LMF (p=0.0129). Conclusion: Distal spiral TSFs were highly associated with malleolar fractures, which may occur at single or multiple sites. A CT scan of the ankle joint is essential to avoid misdiagnosis and the potential need for additional fixation of malleolar fractures in distal spiral TSF. Age was associated with the severity of malleolar fractures, particularly with LMF and AITFL avulsion fracture in distal spiral TSF, but not with PMF or MMF.