As the fibula has little weight-bearing responsibility, Inner Body says its primary function is to provide muscle attachment. This bone is located in the calf, lateral to the tibia, and is the smaller of the two lower leg bones. Both ends of the fibula attach to the tibia with ligaments
SportsInjuryClinic.net says the lateral collateral ligament on the outside of the knee joint attaches the fibula to the upper leg bone, the femur. This combination provides protection from impacts that affect the inner surface of the knee.
Most injuries to the fibula occur along with injuries to the tibia. About.com recommends a close examination of the other bones in the ankle any time one experiences a fracture of the fibula. Because its function is not to support weight, fibula fractures that don't involve other bones don't require a cast; a brace is sufficient. Individuals suffering these injuries often use crutches for the initial few days to allow sufficient time for pain and swelling to subside. Rehabilitation begins quickly after the injury.
Inner Body says the fibula is the bone medical providers often choose for bone tissue when needing to make grafts in other parts of the body due to its lack of responsibility in bearing weight.