What is the Calcaneal Tendon?
In humans this is known as the ‘Achilles’ Tendon and it runs over the back of the heel to facilitates extension of the hock and flexion of the digits. It is made up of three different tendons from various muscles throughout the limb. The calcaneal tendon is a vital part of normal function of the hock (ankle) joint in the dog and when it is diseased or torn this results in collapse of the joint.
What signs will I see in my dog?
Dogs with calcaneal tendon rupture or disease typically present with a ‘dropped’ stance or with a non-weight bearing lameness. In some dogs this will be a chronic, degenerative change that may present slowly over time, in others it may be due to trauma and will be acute. With acute tears there can be a small wound present over the calcaneal tendon that has resulted in weakness or tearing of the fibres.
How is Calcaneal tendon rupture/disease diagnosed?
During your initial consultation, one of our orthopaedic surgeons will assess the way that your pet is walking as well as perform a full orthopaedic examination. Examination of the hock joint will show hyperflexion of the hock joint while the stifle (knee) joint is hyperextended – if the calcaneal tendon was intact this would be unable to be performed. The tendon will be examined for any wounds or evidence of a tear or rupture. Radiographs will then be performed under sedation to assess whether the tendon itself has torn or if the bone that the tendon attaches to (calcaneus) is fractured.
How is this treated?
Conservative management for any calcaneal tendon rupture is not likely to be successful. Tendons in the body have a limited blood supply so are not able to heal well without perfect approximation and adequate strength/stabilisation. Surgery is required for a good long-term outcome.
Surgery normally involves either a repair of the fractured bone or a soft tissue repair with non-absorbable suture material in the tendon itself to allow the tendon to heal together. Fractures are repaired with either a plate and screws or pins and wire depending on where the fracture is located. Recovery from this normally takes approximately 6-8wks, allowing time for the bone to heal back together.
Primary repair of the tendon takes a longer time as the tendon is not as fast at healing as normal bone. Once the repair is in place a screw is placed through the calcaneal and tibial bones to hold the joint in an extended position, this allows the tendon to heal while avoiding tension across the surgical site. The screw is normally removed at 6wks post operatively.
What does recovery involve?
It is very important that while the tendon is healing, your pet be as quiet as possible to allow the tendon to heal – this means crate rest and short lead walks for toileting only. After surgery, a bandage and cast will be placed on the limb and will remain in place for between 6-8 weeks until the screw has been removed and the tendon is strong enough to start taking some load. Once the bandage has been removed, physiotherapy can start which can be facilitated by our in-house physiotherapist. We expect a full recovery time between 3-6mths for this surgery.
What are the possible complications?
Complications with this surgery include surgical site infections and breakdown, implant failure, recurrent tendon tearing as well as other bandage complications (mostly pressure sores). We always do our best to reduce the risk of these complications and it is important to keep them as quiet as possible during the recovery period.
What is the prognosis?
The prognosis for a calcaneal tendon rupture after a successful surgery is good. The tendon will never regain 100% of the strength it previously had but it will be strong enough to tolerate day to day activity as normal once it has healed.