A hemilaminectomy refers to a surgical approach in the treatment of diseases of the spine, most commonly disc diseases or damage, effecting the spinal cord. The most common condition treated by a hemilaminectomy is intervertebral disc disease (IVDD).
What is intervertebral disk disease and how common is it?
IVDD is a common back problem in dogs, also known as spinal cord dysfunction and sometimes referred to as a “slipped disc”. In between the vertebral columns or bones that make up the structure of your dogs’ spine are little fibrocartilaginous cushions – the discs – that act as shock absorbers as well as giving support to the spine structure, allowing movement and flexibility. During IVDD, these cushions are thought to dehydrate, lose their sponginess, and become brittle. This can cause them to slip out of place and potentially compress the spinal cord. The result of spinal cord compression is that nerve impulses struggle to reach the extremities. Ultimately this leads to the loss of function of limbs as well as affecting bladder or bowel function.
Although IVDD, a degenerative (worsening) age related disease, is the most common cause of a slipped disc; it can also occur due to injury.
What symptoms would you see in your dog if they were suffering with IVDD?
Dogs suffering from IVDD may first develop signs of lameness. It may be that it’s difficult to ascertain which leg appears to be the problem. Or they can sometimes be lame on different legs at different times. IVDD is a degenerative disease that progresses over time. But patients can suddenly lose function of their limbs if the disc suddenly moves into a position where it affects the spinal cord totally. These dogs present to veterinarians “off their legs” or non- ambulatory and sometimes appear paraplegic (unable to use any of their limbs).
Are certain breeds more likely to develop back problems?
Dogs which characteristically have disproportionately short and curved limbs such as Dachshunds, French bulldogs, Basset Hounds, Lucas Terriers, Pugs and Shih Tzus, are typically seen to suffer from IVDD more commonly due to their predisposing genetic bone structure. Although IVDD is thought to be a disease of older animals, in these breeds it can be seen in young or middle-aged dogs because these dogs suffer early, degenerative changes in the disc making them more likely to herniate (or slip out of place).
What tests would your dog have to determine if they had a back problem?
Your vet will likely perform a general health blood screen to check for other causes of back pain and make sure it is safe for your pet to undergo imaging. At your GP vet level, it may be useful to perform x-rays. But ultimately your dog will require more advanced imaging such as magnetic resonance imaging (MRI) or myelography to see the structures in the back in more detail to plan treatment effectively.
A bit about the surgical approach
A hemilaminectomy involves approaching the spine surgically from the top of the back, at the side. This gives access to the top edge of the vertebrae (bones of the spine); at which point a small portion is removed to give access to the internal structures such as the slipped disc itself. The spinal cord is visible now too; so surgeons can work on removing any diseased discs that are compressing the spine, causing problems; whilst trying to free up and limit damage to the spinal cord itself. Whilst new or synthetic discs are not replaced in this procedure, commonly screws are inserted to do some of the job of the removed discs and keep spinal stability.
How successful are hemilaminectomies in treating IVDD?
Clinical studies, and results seen at home with pets every day, show better success with surgery than a conservative approach alone (pain relief, anti-inflammatory drugs, and rest). Although this is, to an extent, dependent on the severity of disease and level of spinal cord compression. And therefore severity of symptoms seen in your dog prior to treatment. Surgery is especially recommended for those unable to stand and walk on their own (non- ambulatory dogs) when diagnosed. As without surgery, these patients have a very much reduced quality of life and concerns regarding their welfare.
The prognosis for dogs with IVDD that still had pain reception in at least 1 of the hind limbs or tail before surgery was good.
Some possible complications during and after surgery
Potential complications during or as an immediate result of hemilaminectomy surgery include trauma to the spinal cord, bleeding, infection, and spinal instability. This is due to the surgery taking place in such close proximity to sensitive vital structures; such as the nerve highway of the body, the spinal cord itself, as well as major blood vessels.
This is a very specialist surgery and is usually performed at referral level by highly trained veterinarians. Therefore complications are minimised as much as possible.
Long-term complications could include, incontinence (lack of urinary or faecal control); permanent neurologic deterioration (inability to walk or stand); and self-mutilation (causing harm to their own limbs due to on- going pain or tingling sensations). These complications are more common in those with severe symptoms prior to treatment, such as those that cannot walk or stand when diagnosed.
Post operative rehabilitation
Recovery time is variable, but dogs are usually up and walking within weeks to months. Strict rest/confinement is recommended for about 1-month post-surgery with gradual increase in activity guided by your vet afterwards.
Rehabilitation therapy can speed recovery. Physiotherapy exercises can be started in veterinary hospital as well as neuromuscular electrical stimulation, range of movement exercises and sling walking. Exercises can then be passed on for owners to complete at home with their dog including sling walking and elimination management. These are usually demonstrated and facilitated immediately on discharge from hospital for the primary post operative period.
Hydrotherapy treatment (such as underwater treadmill) significantly improved the progress and of recovery and can be initiated 10-14 days post-surgery.
So, what is a hemilaminectomy?
It is a surgical approach to treat common back problems such as IVDD in dogs that causes loss of mobility, with the aim to restore limb function (and potentially bladder/ bowel function).
Speak to your veterinary surgeon about the risks and benefits associated with surgery of this type for YOUR dog; as the outcome very much depends on the clinical exam performed by your vet, its findings, alongside your dogs’ symptoms and results of advanced imaging.
Together, you can make the best choice for your dog.
If you have concerns about IVDD or need advice following a diagnosis requiring surgery such as a hemilaminectomy, speak to your veterinary team who will be able to advise you.