A Gustilo Type 3B Open Tibial Fracture Treated with a Proximal Flexor Hallucis Longus Flap: A Case Report

INTRODUCTION: In the treatment of Gustilo Type 3B open tibial fractures, it is important to perform soft tissue reconstruction and bone reconstruction simultaneously. Gastrocnemius muscle and soleus muscle flaps are generally used as rotational flaps for the tibia. The distal third of the tibia can often not be covered with the gastrocnemius muscle and soleus muscle flaps. Treatment distal to the distal third of the tibia is difficult because fewer flap options are available. In the present report, we describe our experience with a Gustilo Type 3B open tibial fracture treated by gastrocnemius muscle and soleus muscle flaps, along with an additional proximally based flexor hallucis longus flap, which is a rare procedure. CASE REPORT: The participant was a 17-year-old male who injured his left tibia in a motorcycle traffic accident. Physical examination revealed a wound of 13 cm × 7 cm extending from the medial lower leg to the posterior aspect, with extensive skin loss. There was no nerve or vascular injury. The tibia was exposed, with detachment of the periosteum. The radiograph revealed a tibial shaft fracture. The AO/OTA classification was 42-A3.3, and it was classified as a Gustilo-Anderson Type 3B fracture. Gastrocnemius muscle and soleus muscle flaps were lifted in the area of the soft-tissue defect and then, placed over the tibia. Despite this, the distal portion of the tibia remained uncovered. Therefore, a flexor hallucis longus flap was lifted and placed over the distal portion of the tibia. On day 7 after the injury, the external fixation device was removed and the tibial shaft was fixated with two Ender nails (4.5 mm in diameter). The clinical course was satisfactory, and the skin graft and flap were successful. Bone union was achieved without infection, and the resulting range of motion was normal. CONCLUSION: For the treatment of Gustilo-Anderson Type 3B open tibial fractures, early treatment of the soft-tissue defect is vital. We surgically treated a Gustilo-Anderson Type 3B open tibial fracture with gastrocnemius muscle and soleus muscle flaps, along with an additional proximally based flexor hallucis longus flap, which is a rare procedure. In the event of a soft-tissue defect in the distal third of the tibia, the use of a proximally based flexor hallucis longus flap is an effective surgical approach.