An injury to the ankle can be debilitating. Most commonly it occurs from rolling the ankle while weightbearing. This creates an ankle sprain which is a soft tissue injury to the ligament structure around the ankle joint. Depending on the severity of a sprain recovery can take up to 4-6 weeks with rehabilitation speeding up this process. Ligaments stabilise joints and prevent excess movement, so it stands to reason that a significant soft tissue injury causing lack of stability may cause the joint to become unstable and may roll so much that the actual joint or part of is damaged. This can then create cartilage or bone damage around the ankle.
If an ankle injury does not heal at a certain pace then there may indeed be bone injury but due to the swelling and position of the bone it may not show up on xray. A xray will often be taken immediately after an injury and if it shows nothing then the ankle will be classed as a sprain and treated conservatively with physiotherapy. So if there is not significant improvement with therapy often a bone scan/MRI may be performed to see what other structures may be injured.
A common injury or complication to ankle sprain is talar dome injury. The talar bone is one of the major bones that make up the ankle joint. The dome aspect of the talus bone, which is the joint surface, may become damaged with excessive movement on injury. A talar dome injury may be just to the cartilage attached to the bone or to the bone itself or a combination of both.
Treatment of this type of injury varies depending on the severity. A severe talar dome fracture where the bone is displaced will usually need internal fixation under surgery. This type of injury would usually be found on xray immediately, as it should be quite obvious. Other less severe injuries may require a period of immobilisation for a few weeks. Others may just require non-weight bearing through the ankle, while very mild talar dome injuries will be treated as a normal sprain except it is accepted that they will take longer to heal than your normal 4-6 weeks.
It is vital to find out how severe an injury is and get some guidelines to management through your doctor and physiotherapist. Just remember these types of injuries have the same long-term complications as your ankle sprains. These are: Ankle stiffness, balance problems, recurrent injury so management and exercise advice from your local physiotherapist is vital even for a minor ankle injury. Early rehabilitation such as ankle mobilisation and exercise have shown to prevent long term pain and complications of the ankle.