Tibial Tuberosity Advancement (TTA)

Tibial Tuberosity advancement surgery is indicated when the anterior cruciate ligament has torn or ruptured completely. There is no way to successfully repair the ligament. Following prolonged instability of the joint it is likely that damage will have occurred to the menisci (pads of cartilage in the joint to act as shock absorbers), damage to this cartilage will cause arthritis.

Tibial Tuberosity Advancement Surgery (TTA) involves changing the weight bearing angle of the joint to prevent the tibia slipping forwards. This change in angle eliminates the need for a cruciate ligament and the joint becomes stable again.

Diagnosis:

Radiographs are taken of the joint under general anaesthetic. This helps us to assess the level of swelling and arthritis in the joint and enables the surgeon to take accurate measurements needed in order to plan and perform surgery specifically for your dog.

On diagnosis of cruciate disease your dog will be given anti-inflammtories to relieve pain in the joint, and strict rest will be advised with a view to performing surgery in the following weeks.

 The night before surgery:

You can feed their normal diet in the evening, ideally no later than 8pm. Fresh water should be left down overnight but taken up first thing in the morning. Do not feed any breakfast; it is important the stomach is empty before giving a general anaesthetic to prevent vomiting. Please ensure your dog has been to the toilet before coming to the surgery.

The day of surgery:

The operating veterinary surgeon or a registered veterinary nurse will admit your dog in the morning. All the details of the procedure will be explained again and you will be asked to sign a consent form which gives us permission to give a general anaesthetic to your dog and perform surgery.

Once your pet is admitted to the surgery, they will be provided with a comfy bed and a non-slip mat to aid stability in their kennel. A blood test may also be taken to screen for any underlying problems before anything else is done. This will be discussed with you at the time of admission.

A pre-medication, consisting of a light sedative and strong pain killer, will be administered twenty minutes prior to surgery which help keep your pet calm, making induction into anaesthesia much easier and stress free. Your pet will have a clipped patch on their front leg where an intravenous catheter will be inserted; through this we will inject the induction agent (propofol, also used in humans) and administer fluids to aid blood pressure.

Once your pet is under general anaesthesia, they will be maintained on a gas anaesthetic (isoflo or sevoflo mixed with oxygen) via an endotracheal tube placed down their trachea. Intravenous antibiotics and additional pain relief are given at this point.

The affected limb will then be prepared for surgery. Preparation involves clipping a large area of fur from hip to hock; this is to prevent fur from contaminating the surgical site. The hairless skin is then scrubbed thoroughly using a surgical scrub.

The veterinary surgeon will make the first incision directly over the stifle joint. The joint is opened and examined for any arthritic changes or damage to the menisci. The meniscus will be removed, or partially removed, if it is badly damaged.

The surgeon may need to extend the incision to fully expose the tibia. A pilot hole is then made at the base of the tibial crest. This is to mark where the bone will be cut to. The wedge of bone is then levered forwards and held in place using a specialised cage. The levered section of bone is then secured with a plate.

The surgical site is then sutured over using dissolvable sutures; no external nylons stitches are placed.

Post-operative radiographs are taken to confirm the position of the implants and angle of the joint. 

After the surgery:

The affected limb is iced immediately after surgery to help relieve swelling and pain. Your pet will be moved back to their kennel for recovery where they will be kept warm and monitored closely. We will contact you as soon as the anaesthetic equipment has been turned off to inform you that the procedure has now taken place.

We may place a light adhesive dressing over the wound to protect it for the next 24 hours, this can be removed at home the following day. The dressing will absorb any discharge from the wound as stitching through the skin can cause it to ooze.

As soon as your pet is able to sit up and eat we will offer them fresh water and a meal as this helps to speed recovery and increase their body temperature.

Your pet will need to stay as an inpatient overnight to ensure they stay confined and rested, however they will be taken outside on a lead to toilet and walked at a very slow pace. High strength pain relief and antibiotics will be given at regular intervals.

The on duty vet will come into the surgery during the night to administer pain relief and to take them out for toileting.

A nurse will be in attendance from 8am the following morning to administer pain relief and take them out for toileting, the veterinary surgeon will also examine them before we contact you to arrange a discharge appointment.

Discharge information:

A veterinary surgeon or registered veterinary nurse will discharge your pet and discuss all the details of the procedure. We will put together a discharge pack for you which will include a copy of the post operative radiographs, a list of gentle exercises that can be performed when you get home, a course of pain relief and antibiotics, an ice pack and a buster collar.

What to expect when you get home:

Your pet may be drowsy when you get home; hospitalised patients will relax when they get home and may sleep a lot which is perfectly normal and to be expected. The pain relief medication can also cause drowsiness.

Your pet may develop a cough, this would be due to the endotracheal tube being placed down their trachea to help them breath during the anaesthetic, this is nothing to be concerned about and would normally settle within a few days.

It is quite common for TTA patients to be walking and weight bearing very soon following surgery, however in some cases they may continue to be lame for a few days. It is important to encourage weight bearing on the affected limb but no more than your pet is comfortable with. Restricted movement will be advised for the first week or more, a large crate or small room without furniture is ideal. Your pet should be taken out for toileting purposes only on a very short lead to aid slow walking. A ramp may be required if there are steps to your garden. Your pet must not be allowed up and down the stairs or in and out of the car without being lifted.

The surgical site and surrounding area may be swollen for a few days, especially around the hock area as fluid is able to collect there. The swelling will reduce over time with the aid of movement and icing. The limb may also become very bruised, this is to be expected as some manipulation of the limb is required during surgery. Arnica cream can be applied to relieve this but do not let your pet lick it off!

A buster collar/Elizabethan collar will be provided to prevent your pet from licking the wound. It is essential to keep the wound dry and protected. Please remove the dressing that was applied the day before and allow the air to circulate. It may be necessary to dampen the edges of the dressing with a cloth. The skin may be sensitive around the wound, do not be concerned if you cannot remove the dressing. The wound may continue to discharge for a few days, this is normal. The discharge may be slightly red and bloody but should be very watery, this is not a concern. If the discharge is very thick, dark red in colour and persistent please contact us immediately.

A registered veterinary nurse will visit you the day after your pet returns home to examine the wound and answer any questions you may have. The nurse will also help to remove the dressing if you have been unable to.

The next step:

An initial assessment with our chartered physiotherapist is highly recommended within the first two weeks following surgery. She will be able to assess the level of muscle wastage and range of movement in the limb. She will give you some exercises to follow at home and may recommend a course of hydrotherapy either in the pool or water treadmill with a registered veterinary nurse.

Follow up radiographs are required six weeks post operation to assess the level of new bone growth at the surgical site.

At this point your pet should have vastly improved, however further rehabilitation may still be required.

Complications:

As with any form of surgery problems and complications can occur. TTA surgery is major orthopaedic surgery and is successful in the majority of cases.

Stresses and strains:

The aim of the surgery is to ultimately change the weight bearing angle of the joint, this in turn can put extra strain on the surrounding structures in the stifle joint. The body gradually adapts to this alteration but care must be taken for the first few weeks following surgery to prevent excessive strain. Problems such as sprains and strains of the ligaments and tendons can occur. Fractures can occur at the pilot hole. The levered section of bone can fracture at the base, this is not a concern as the plate stabilises this section. In rare cases the tibia can fracture from the pilot hole, this is very uncommon and revision surgery may be required to repair the fracture.

Delayed healing:

Individual patients heal and progress in different ways. Some patients may be walking well and weight bearing within hours of surgery. Other patients may take a few weeks to gain confidence on the leg. Physiotherapy will help to improve weight bearing and muscle tone.

Post operative meniscal injury:

The joint is fully inspected during surgery; in early cases of cruciate disease the meniscus may appear normal at the time of surgery, however meniscal tears can occur in the weeks and months following surgery. Late meniscal injury is less likely to occur after TTA surgery than any other surgical repair. Sources quote a 15% chance of post operative meniscal injury, at present we have a 0% meniscal complication rate following TTA surgery.

Relatively simple revision surgery may be required if the problem is severe.

Infection:

Infection is uncommon but can be difficult to treat following surgery. Antibioitcs are given at the time of surgery and five days following. Reactions to the implants can cause infection and inflammation. A further course of antibiotics will be required and further surgery to remove the implants if necessary once the bone has healed.

Payment:

The cost of the surgery is around £2000, this includes post operative visits from the nurse and radiographs at six weeks.

Most insurance companies will cover your pet for this surgery, although it is advised to check with your insurance policy first.

It is practice policy for all payments to be made when you collect your pet from the surgery. A signed claim form can then be submitted to us for processing and the insurance company will post a cheque to you minus your excess fee.

It may be possible to arrange a direct claim; this must first be discussed with the veterinary surgeon. In this case it is practice policy for the insurance excess to be paid when you collect your pet. A signed claim form can then be submitted to us for processing and the insurance company will pay us directly.

If your pet is not insured or you have any concerns relating to payment, please speak to the veterinary surgeon and we can arrange a meeting with the practice manager to discuss the options.