The Achilles’ tendon or common calcaneal tendon is made up of multiple tendons from several different muscles of the hind limb. The superficial digital flexor muscle and tendon, the gastrocnemius tendon and the combined tendon of the gracilus, semitendinosus and biceps femoris muscles are the main components. A multitude of injuries can occur in the Achilles’ tendon, but two main types of injuries occur most commonly.
- traumatic (lacerations, blunt force trauma, severe stretching/pulling)
- atraumatic (chronic and degenerative in nature)
Any dog or cat can injure the Achilles’ tendon by external trauma (for example, sharp edges coming into contact with the tendon). Atraumatic injuries can be seen in any breed of dog or cat, but Labrador Retrievers and Doberman Pinschers are overrepresented. The cause of this chronic degenerative condition may be due to repetitive injuries.
The signs of an injury to the Achilles’ tendon can vary. Many animals will be lame on that limb with a variable amount of swelling around the injury. An animal with a complete rupture of the Achilles’ tendon will walk “flat-footed” or “dropped” (a plantigrade stance), and the toes can be curled downward (crab claw stance) like the animal is trying to grip the floor (Figure 1). The reason that they can have this “crab claw” stance is that all the components except the superficial digital flexor tendon have ruptured or been cut. The full weight and strain are then applied onto the superficial digital flexor tendon which pulls the digits into flexion.
The physical exam is very important to diagnosing and localizing the injury as well as identifying what therapies might be needed. Other tests that your veterinarian may recommend to diagnose the problem are x-rays (Figure 2) and ultrasound (Figure 3), or other advanced imaging such as CT or MRI.
Aftercare usually includes very restricted activity for 6-12 weeks post surgery and protecting the surgery repair with the aforementioned options for that time. If your veterinary surgeon has applied a splint or cast to your pet’s limb, regular bandage changes and monitoring will be required while the bandage is in place. In the case of orthotic use, there may be repeated adjustments made to the device to increase levels of strain on the tendon during the recovery and healing phases. Often times some element of physical therapy, either at home through the guidance of your surgeon or with a certified veterinary physical therapist, is indicated in order to re-establish an appropriate range of motion in the tarsus.
Potential complications include re-rupture or break down of the surgical site. These can often be avoided with appropriate postoperative care and restrictions.
The prognosis is usually very good for the majority of injuries. Between 70-94% of dogs have a good to excellent return to function.