Background: The posterior tibio-fibular ligament is attached to the PM, thus if the PM is affected, disruption of the ankle congruency develops. Plain radiography provides insufficient evaluation of the pathoanatomy of the PM fragment. However, MSCT images determine the accurate morphology of the PM fracture, thus all patients with ankle fractures should be assessed by preoperative MSCT imaging.
Objective: The aim of this study was to assess: the morphological characteristics of the PM fragment, the correlation between the fragment height (FH), the affected articular surface area, the fragment area ratio (FAR) and the fragment length ratio (FLR), the relationship between the FH and the die-punch.
Methods: This study was retrospective, included 85 patients, 34 were men (40%) and 51 were women (60%), mean age was 52.38±16.25 years. Patients who underwent surgery for a unilateral ankle fracture involving a PM fracture were included in this study. All patients underwent plain radiography and MSCT .
Results: 76.5% were trimalleolar fractures, 23.5% were bimalleolar fractures, no isolated PM fractures. Weber type B fractures were the most common, occurred in 68.2%. The FH correlated positively with the fracture area, as well as the FAR, and the FLR. The mean FH increased in the positive die punch group. Type II PM fractures were the most common occurred in 47.1%.
Conclusion: Preoperative assessment of the FH, area, FLR and FAR with MSCT imaging can help the orthopedic surgeons in determining the appropriate surgical approach, thus restoring the syndesmotic stability, and ultimately improving the functional outcomes.