50kg Mastiff Gets Surgery For Ruptured Cruciate Ligament

Dr Tan Choon Yi, Mount Pleasant Veterinary Centre (Changi)

Dandelion is a 3-year-old English Mastiff. In September 2014, she became lame on her right hind limb and was treated with a course of anti-inflammatories. After 2 courses with no improvement, Dandelion was scheduled to have her knee examined by Dr Dennis Choi (Mount Pleasant Veterinary Centre, Gelenggang) under general anaesthesia.


General anaesthesia allows the patient to be adequately relaxed for a proper examination of the knee, which can be difficult in a conscious large dog like 50kg Dandie!

Upon examination, there was an instability of her knee reflected by a positive cranial drawer test. This confirmed a cranial cruciate ligament rupture.


In a drawer test, the vet holds the femur stable and moves the tibia. If the tibia is able to move forward (like pulling out a drawer), it is considered a positive drawer test which indicates a cranial cruciate ligament rupture. (ref: morningtonvetclinic.com.au)


The cranial cruciate ligament is the primary stabiliser of the knee. Once it ruptures, the dog will become acutely lame due to severe inflammation that occurs within the joint. (ref: michiganveterinarysurgeons.com)

Lateral stifle-before surgery

Radiographs of Dandie’s knee showed an increased radio-opacity in the infrapatellar fat pad, which can occur in cruciate disease.

Dandie’s surgery, performed by Dr Choi, is called a cranial tibial wedge osteotomy. A triangular wedge of bone is cut from the tibia to change the angle of the weight bearing surface of the knee. This prevents abnormal sliding motion of the joint which occurs after the cruciate ligament has ruptured.

Lateral view of stifle

AP view of stifle

2 bone plates with pins and wires were placed to close up the wedge made in the tibia.

By the first week, Dandie was able to place weight on her right hind leg but still visibly lame. 2 weeks after surgery, she was feeling better and to my dismay, trying to run and jump. Activity had to be restricted for a full 12 weeks until bone healing was complete. Premature, uncontrolled activity can risk breakdown of the surgical implant.

Dandie post surgery

Dandie before surgery

A seroma (sterile accumulation of fluid), almost the size of a fist, had also developed at her surgical site. No specific treatment was required for the seroma and it was resorbed by her body in about three weeks.

Dandelion has since made a full recovery from surgery and is back to her mischievous self – jumping onto sofas, stealing random items from the garden and chasing birds every morning!

Baking at the printers! Find out more about our vets & their pets in our next issue of Pleasant Pet News. Pick up your copy at all our clinics this month!

Baking at the printers! Find out more about our vets & their pets in the next issue of Pleasant Pet News. Pick up your copy at all our clinics this month!