The fibula is the bone on the outside of the leg and is the smaller of the two bones of the lower leg (the other is the tibia or shin bone). The tibia handles most of the weight bearing responsibilities while the fibula contributes to the stability of the knee and ankle joints. The fibula keeps the ankle joint in line and helps, along with the ligaments, to prevent ankle sprains.
However, an injury to one’s ankle can cause the fibula to become fractured. The break can be undisplaced (a small crack) where only a brief period of restricted weight bearing is needed, or it can be completely displaced (moved out of position entirely) and shortened. When a displacement occurs, the mechanics of the ankle joint can be disrupted.
Sometimes the injury pattern can involve a ligament that holds the tibia and fibula together, in which case a separate pin needs to be inserted. If the fibula break is displaced, surgery will be needed. This means opening the break through a skin incision and visually “reducing” (putting back in place) the break and securing it with plates and screws. Once surgery is completed, the recovery phase begins. It takes at least six to eight weeks for most broken bones to be stable enough for walking on. Some take longer and some breaks may develop delayed or non-union, where healing is prolonged for an indefinite period of time.
Being a runner and practicing proper nutrition are both beneficial attributes to ensure appropriate healing times. Some broken bones require a period of casting while in other cases, the use of the plates and screws replaces the need for a cast. After it has been determined (through x-ray assessment) that the break is healed, partial weight bearing followed by then full weight bearing are allowed.
Although the bones may be “healed” on x-ray, the healing process is not nearly over. The six weeks or more of immobilization can produce atrophy and weakness of the muscles and ligaments of the leg, which then requires a rehabilitation program to restore them to their pre-injury status. Physiotherapy is very important to regain the strength and proprioception (joint sense) of the limb. This will speed the athlete’s rehabilitation and return him or her to the chosen activity. Any injury requires a graduated re-entry into the system. For a fractured fibula that required open reduction and internal fixation (ORIF), I usually tell the patient that it will take at least six months to return to the pre-injury level, and often it may take a year. Sometimes, after a year or two, the plates and screws need to be removed due to local irritation, which can further delay the athlete’s return. My best advice is to follow the process and schedule developed by your physiotherapist to gradually increase strength, range of movement, balance and sensory modalities.
Dr. Richard Beauchamp is an orthopedic surgeon based in Vancouver. He is the medical director of the Shriner’s Gait Lab at Sunny Hill Health Centre and a clinical professor in the Department of Orthopedics at the University of British Columbia. He is an avid runner and walker who has completed seven marathons.