OBJECTIVE Detection of tibial fractures in which a concomitant ankle injury may exist. METHODS Prospective study. METHODS Department of Trauma Surgery, University Hospital. METHODS 43 (20.1%) of 214 patients with a tibial fracture were found to have an associated injury of the ankle joint. METHODS Analysis of all patients with tibial fractures regarding typical mechanisms of injuries and typical radiographic criteria for concomitant injuries of the ankle joint. METHODS Primary x-rays were analyzed looking for spiral fractures of the tibia or proximal fibular fractures or an intact fibula, typically associated with syndesmotic injury. The assessment of patients was based on radiological findings and functional recovery. RESULTS 45 ankle injuries in 43 patients were found. There were distal fibular fractures in 14, Maisonneuve fractures in 13, isolated ruptures of the syndesmosis in 3, fractures of the posterior malleolus in 8, and fractures of the medial malleolus in 7 of the cases. In 38 of the 43 patients, the distal tibiofibular syndesmosis was ruptured, and 88.4% of the tibia injuries were spiral fractures located in the distal third. Of the 38 patients who could be followed, 31 were categorized according to the Phillip's Score as very good, 3 as good, 2 as satisfactory, and 2 as unsatisfactory after an average of 19.8 months (12-26). CONCLUSIONS Due to the obvious injury of the tibia, the potential instability of the ankle joint is often overlooked, and the risk of development of secondary osteoarthritis is often consequently underestimated. Added attention should be paid to the ankle in the following tibial fracture cases: pronation-eversion trauma, spiral fracture of the tibia, proximal fibular fracture, or intact fibula. Using these markers, we were able to diagnose 20.1% of combined injuries compared to our retrospective study in 1999, in which only 13.6% of these injuries could be detected (Pearson r=0.1305, not significant).