Gastrocnemius Tendon Rupture

What is the Achilles’ tendon?
The Achilles’ tendon, also known as the common calcaneal tendon, is a composite structure formed by the tendons of several hindlimb muscles. Its primary components include the superficial digital flexor tendon, the gastrocnemius tendon, and the combined tendons of the gracilis, semitendinosus, and biceps femoris muscles.

Common Achilles’ Tendon Injuries

Achilles’ tendon pathology can arise in many forms, but two main categories are most frequently encountered:

Traumatic injuries

• Breeds: Any
• Causes: Lacerations, blunt trauma, excessive stretching or forceful pulling

Atraumatic (chronic/degenerative) injuries

• Breeds: Any dog or cat, with increased incidence in Labrador Retrievers and Doberman Pinschers
• Causes: Repetitive microtrauma, idiopathic degeneration, hypothyroidism, Cushing’s disease, immune-mediated polyarthritis

Clinical signs suggesting Achilles’ tendon injury include:

• lameness or limping of the affected limb,
• a characteristic “crab claw” stance,
• swelling in the region of the tendon,
• a plantigrade or dropped-ankle stance, where the animal bears weight on the heel rather than the toes.

Once the problem is localized to the Achilles’ tendon and tarsal (ankle) region, diagnostic tests are selected to characterize the injury and guide treatment.

Physical examination
A thorough orthopedic exam is critical to localize the lesion, assess pain, and evaluate limb function.

Radiographs (X-rays)
Radiographs assess the tarsal joint and the calcaneus (the bone where the tendon inserts), identifying fractures, mineralization, arthritis, or concurrent bone disease.

Ultrasound
Ultrasound allows direct visualization of the Achilles’ tendon and is useful for determining the extent, location, and type of tendon damage.

Computed Tomography (CT)
CT provides detailed, three-dimensional assessment of the ankle and associated bony structures.

Magnetic Resonance Imaging (MRI)
MRI offers advanced evaluation of tendons, ligaments, and surrounding soft tissues, including the Achilles’ tendon itself.

Management depends on the severity and nature of the injury and may include:

External support
Orthotics, splints, or casts may be used to stabilize the limb and protect the tendon.

Surgical repair
Surgery may involve reapposition of healthy tendon ends using sutures, mesh, or graft materials. Postoperative protection is essential to allow healing. Limb immobilization can be achieved using casts, splints, custom orthotics, temporary screws, or external skeletal fixation systems.

Tarsal arthrodesis (ankle fusion)
In cases of complete tendon rupture or severe joint damage, fusion of the tarsal joint may be required. This procedure stabilizes the joint in a functional standing position using orthopedic implants, eliminating pain and lameness but sacrificing normal joint motion.

Adjunctive therapies

• platelet-rich plasma (PRP),
• extracorporeal shockwave therapy,
• stem cell–based treatments.

Postoperative management typically requires strict activity restriction for 6–12 weeks, along with continued protection of the repair. Full tendon healing may take 9–12 months. Regular rechecks are often necessary to adjust external support. Physical rehabilitation, either home-based or supervised by a veterinary physiotherapist, is commonly recommended to restore appropriate ankle motion.

Potential complications include failure of the repair or re-rupture, most of which can be minimized with appropriate postoperative care.

Prognosis:
Overall outcome is favorable. Approximately 70–94% of dogs achieve a good to excellent functional recovery.