The medial malleolus is the end of the shin bone or tibia and appears as a bump on the inner side of the ankle joint. It forms the support for the inner side of the ankle joint as it is also the point of attachment of the deltoid ligament on the inner side of the ankle.
A forceful rolling of the foot either inwards or outwards may result in an isolated fracture of the medial malleolus as a compression due to inward roll or a tension due to outward roll may both cause breakage. A medial malleolus fracture can also occur as a stress fractures in which weakening of the bone occurs due to repetitive stress of an activity as seen in endurance athletes or military recruits.
These fractures can be classified into five types based on the actual orientation of the fracture line:
- Chip Fractures: These occur due to ligament rupture on the inner side of the ankle.
- Transverse Fractures: These occur in the same direction as the ankle joint line and are generally small bone fragments.
- Oblique Fractures: It occurs at the corner of the ankle joint usually associated with a rotational injury that starts on the outside of the ankle.
- Vertical Fractures: These occur on orientation of the force in the leg bone and may extend into the weight bearing portion of the ankle joint.
- Comminuted Fractures: They are generally high-energy injuries that cause the breakage of the bone into multiple pieces.
The fractures of the medial malleolus are usually associated with a rolled ankle due to:
- Significant weight bearing forces.
- awkward landing from a jump (particularly on uneven surfaces),
- a fall
- Direct blow to the front or inner aspect of the lower leg or ankle.
- A stress fracture of the medial malleolus may occur as a result of overuse often associated with a recent increase or high volume of running.
The major symptoms experienced by patients with a medial malleolus fracture include:
- A sudden onset of sharp, intense inner ankle or lower leg pain at the time of injury.
- Difficulty in weight bearing
- Pain in the front or inner aspect of the ankle or lower leg on standing or attempting to walk
- Swelling, bruising and pain on firmly touching the affected region of bone.
- An obvious noticeable deformity may form.
- Pins and needles or numbness in the lower leg, foot or ankle.
A fracture of the medial malleolus may be diagnosed through thorough subjective and objective examination from a physiotherapist. Additionally X-ray, MRI, CT or scans may be analysed to confirm diagnosis and assess the severity of the fracture.
Medial malleolus fractures may be treated by both non-surgical and surgical methods. Surgery is recommended in case of fractures that are displaced or those that occur in very active patients. However many researches claim that medial malleolus fractures treated without surgery heal better. So non-surgical treatment is preferred when fractures are not out of position, patients are relatively more sedentary and the fragment of bone is too small to be effectively repaired.