Risk factors include:
- Steroids (systemic or previous injections in/around tendon)
- Achilles tendinopathy
Be aware that even a complete rupture may not be painful, and that patients with an Achilles tendon rupture may still be able to stand on tiptoe and plantarflex against resistance, due to other plantarflexors masking the weakness.
One of the possible signs is an altered angle of declination. What this means is that, when the patient is lying prone on the couch with their feet dangling over the edge, the affected foot will be in a less plantarflexed position. Simmonds triad, which is considered diagnostic, consists of:
- Calf squeeze test – reduced plantarflexion (sensitivity 96%)
- Altered angle of declination (sensitivity 88%)
- Palpable gap (sensitivity 73%)
The three combined have a sensitivity of 100%. Specificity not given here, but at least that means we’re not going to miss one.
Manage suspected rupture by referring to orthopaedic surgeon (or sports physician, but in most cases that’ll be a moot point locally) same day. Treatment may be surgical or non-surgical, with no clear evidence as to which is better; either needs to be followed up by several months of physiotherapy. Prognosis is good, but recovery takes time – a median of three months to get back to walking and stair climbing, and nine months to return to sports.
Finally, some studies have found (unsurprisingly) that Achilles tendon ruptures carry a high risk of consequent thromboembolism. Discuss the risks and benefits of prophylaxis with the patient, and monitor carefully.