Differential diagnosis

The following conditions which may cause pain in and around the Achilles tendon should be differentiated from true tendon pain (which is almost always restricted to the tendon itself)

• posterior ankle impingement
• os trigonum syndrome
• tenosynovitis or dislocation of the peroneal or other plantar flexor tendons
• an accessory soleus muscle
• irritation or neuroma of the sural nerve
• systemic inflammatory disease (1)

Reference:

• 1. Alfredson H, Cook J. A treatment algorithm for managing Achilles tendinopathy: new treatment options. Br J Sports Med. 2007;41(4):211-6