Achilles Tendon Rupture
Achilles tendon ruptures are missed in up to 25% and often misdiagnosed as ankle sprains.
They are more common in men aged between 30-40 years. Steroid injections, weekend warrior and fluoroquinolone antibiotics are associated risk factors. The rupture is usually 4-6 cm above the insertion onto the heel bone. The typical mechanism of injury is either sudden and forced plantarflexion or dorsiflexion in a plantar flexed foot. A POP is often heard, It is difficulty to walk and there is weakness with dorsiflexion. Non-operative treatment is normally for the more sedentary or medically frail individual. Surgical techniques include open, mini-open, percutaneous and arthroscopic repairs. In chronic cases a reconstruction s often required.
Peroneus Tendon Rupture/Disloaction/Subluxation
The peroneus tendons (short and long) run behind the lateral malleolus. They can subluxate or dislocate with rapid dorsiflexion of an inverted foot. Subluxations can cause longitudinal tears of the tendons in particular the short tendon. 
A POP is often felt at the time of injury. Swelling posterior to the lateral malleolus and tenderness over the tendons are typical symptoms. Radiographs are not helpful but may demonstrate associated fractures or anatomic deviations. This injury is best evaluated with MRI. Early cast treatment for 6 weeks if the tendons are reduced can be attempted but the success rate is only about 50%. Acute repair and other surgical procedures such as deepening of the groove, soft tissue transfers are occasionally required.