Limb Sparing Surgery for Bone Cancer (Osteosarcoma)
What should I expect if my dog has been diagnosed with a bone tumour?
Sadly, bone tumours are quite common in dogs. They most frequently affect older large and giant breed dogs, although middle-aged dogs can also be affected. Tumours are also diagnosed infrequently in young dogs. Limping can vary from being mild and progressive to being sudden in onset and severe. Some dogs experience sudden pathological fracture of a bone when they have been exercising vigorously. The most common tumour affecting canine bones is osteosarcoma (OSA). Although bone tumours can involve the forelimbs or hind limbs, certain sites may predominate. The forelimbs (distal radius) is commonly affected by OSA. Sometimes, swelling of the bone above the wrist is evident before lameness is noticed.
How are bone tumours diagnosed?
In most cases, your vet will have taken a radiograph that shows changes in the bone that are consistent with a bone tumour. In almost all cases, the radiographic changes are enough to be confident of the diagnosis of a bone tumour, as the only other causes of similar changes are fungal bone infections that do not occur in the UK. Sometimes, there has been a diagnosis of a break in the bone and an orthopaedic specialist must carefully reassess the radiographs to determine whether the break occurred because the bone was weakened by the presence of a tumour.
What is the prognosis for dogs diagnosed with bone tumours?
When we assess dogs affected by bone tumours, we undertake a process known as “staging”. This involves a total body search for evidence of tumour outside the affected bone. This process involves the use of blood tests, radiographs, ultrasound and CT or MRI scan of the body including the chest, and occasionally biopsy of the tumour or its local lymph nodes. Most dogs have no detectable evidence of cancer elsewhere, although microscopic levels are almost always present. For dogs where no other tumours are found, treatment is divided into surgical management of the bone tumour itself, and anti-cancer medication (chemotherapy) for the microscopic cancer. Options for pain management are limb amputation, radiotherapy, and limb sparing surgery. In dogs affected by OSA, management of the bone tumour alone (i.e. surgical removal of the tumour without anti-cancer medications) results in short survival times (3-4 months). For dogs where anti-cancer medications are used as an adjunct to surgery, survival times are longer. The average dog survives approximately 1 year, although some survival times are significantly longer or shorter than this. Other tumour types have differing survival times. More information on canine osteosarcoma can be found through our oncology and soft tissue service.
Is amputation a good option for my dog?
In some dogs, amputation is a very good option. Response to amputation depends on many factors, including the size and weight of the individual, the animal’s normal lifestyle, and whether or not there are other orthopaedic or neurological problems affecting the other legs. Most dogs will stay in hospital for 2-3 days after surgery and will be able to exercise freely after 3-4 weeks.
Would radiotherapy be a better option for my dog?
Radiotherapy reduces the pain associated with the presence of a bone tumour but does not address the problem of the bone being eaten away by the tumour. Radiotherapy is best reserved for animals where neither amputation nor limb sparing surgery is a viable option. Pain control can be good in the short term, but survival times are short, and pathological fracture of the bone is common, as a result of improved limb use despite ongoing cancer progression.
Would limb-sparing surgery be a better option for my dog?
Limb-sparing surgery involves the surgical resection of the bone tumour itself. The resultant defect is spanned with a metal spacer that is rigidly attached to the remaining bone(s) of the affected limb. Fitzpatrick Referrals is the only centre in the world to offer this method of limb sparing and have used this technology for the management of bone cancer in dogs with great success over several years. Early comfortable use of the limb is typical. This surgery can be an excellent option for large, giant or heavy dogs, dogs whose lifestyle would be severely impaired by amputation or animals with orthopaedic or neurological problems affecting their other limbs. Radial endoprosthesis are used for limb sparing of the forelimb and tibial endoprosthesis for the hind limb.
Is the bionic leg implant (PerFiTS) used for the treatment of bone cancers?
Most animals with bone cancer do not require treatment using the PerFiTS. This innovative technique has been used to treat animals where the lower part of a limb is obliterated either by cancer (bone cancer or soft-tissue cancer) or by severe trauma to bones, muscles, nerves and/or blood vessels. We have treated both dogs and cats with this innovative technology in circumstances where amputation or euthanasia was the only possible alternative.