Rupture usually occurs about 4-6cm above the insertion, in the watershed region and at the usual site of non-insertional tendonopathy. Rupture does not usually occur in a normal tendon. The tendon has areas of degeneration and macroscopically is ragged and unhealthy.
Steroid injection into or around the tendon has been associated with rupture. Although the association has been disputed we do not recommend injection into or around the Achilles tendon.
Other causative factors in rupture of the Achilles tendon include:
- fluoroquinolone antibiotics such as ciprofloxacin - Sode et al(2007) fond the risk in fluoroquinolone users was 3.1 times higher than controls using Danish prescription and diagnostiic registers
- systemic steroids