Isolated posterior malleolus fracture: A case report and review of the literature

Introduction

Fractures involving the ankle joint typically manifest as bimalleolar or trimalleolar fractures, with isolated posterior malleolus fractures (IPMF) representing a rare subset, comprising 0.5–4 % of cases. Due to its rarity and subtle clinical presentation, IPMF poses unique diagnostic and management challenges. This case report presents the diagnosis and treatment of a 50-year-old woman with an IPMF following a fall, alongside a review of relevant literature.

Case presentation

A 50-year-old woman presented with severe right ankle pain and inability to bear weight after a backward fall. Physical examination showed swelling, tenderness in the medial retromalleolar region, and pain with passive dorsiflexion. Imaging through X-rays and CT scans revealed an isolated posterior malleolus fracture involving 40 % of the tibiotalar articular surface. The patient underwent surgical fixation using two posteroanterior cannulated screws via a posterolateral approach. Post-operative X-rays confirmed adequate reduction and fixation. She remained non-weight-bearing for six weeks, followed by physical therapy.

Discussion

IPMFs are challenging to diagnose due to subtle signs and limitations of standard radiographs. Advanced imaging, particularly CT with 3D reconstruction, is crucial for accurate diagnosis. Classification systems, such as Haraguchi and Mason, guide treatment. Surgical fixation is often necessary for fractures involving significant joint surfaces, displacement, or instability. Posteroanterior cannulated screws offer a minimally invasive and effective stabilization method, as demonstrated in this case.

Conclusion

Early recognition and proper surgical management of IPMF are essential to prevent complications. Increased awareness and further research are needed to improve outcomes for this rare ankle injury.