TPLO (Tibial Plateau Leveling Osteotomy)

• Anatomy of the Knee
• Anterior (Cranial) Cruciate Ligament Rupture
• Wagon Model Used to Explain Instability of the Knee Joint
• TPLO Surgery
• TPLO Homecare Instructions
• Physical Therapy
• TPLO Rehabilitation
• TPLO FAQ

Anatomy of the knee

• There are two cruciate ligaments which cross inside the knee joint: the anterior (cranial) cruciate and the posterior (caudal) cruciate.
• The anterior cruciate stabilizes the knee by preventing the tibia from slipping forward and out from under the femur.
• There are two collateral ligaments that stabilize the knee in a side-to-side direction.
• There are two c-shaped cartilage structures (meniscus) that cushion and stabilize the knee by fitting between the femur and tibia.

Anterior (Cranial) Cruciate Ligament Rupture

• ACL rupture is the most common orthopedic condition that we treat. The cause is unknown, but conformation of the limbs and genetics may play a role.
• All breeds of dogs, cats and ferrets can be affected, but some breeds such as Labrador Retrievers, Rottweiler, and Mastiffs are more predisposed.
• Ligament rupture is usually the result of a gradual process, not due to a single traumatic injury.
• Symptoms may begin after sudden stopping, twisting, or over extension of the knee during exercise.
• Many animals have a predisposing factor like age-related ligament degeneration, pre-existing inflammation, anatomical abnormalities or abnormal slope of the plateau of the tibia bone.
• About 33-50% of dogs that have an abnormal cruciate ligament (ACL) will develop a partial or full rupture of the opposite ACL.

How do I know if my pet has this injury?

• Limping is usually the first symptom noticed at home, often after exercise.
• Stiffness and/or very mild lameness are early signs.
• Swelling inside the joint is common, but is usually not externally visible.
• A medial buttress is swelling on the inside of the knee (facing the other knee); this indicates arthritis is developing from chronic irritation.

How do we diagnose an ACL injury?

• The doctor will perform a physical exam and check for 'drawer motion' and pain in the knee. If the ACL has torn, the doctor may be able to slide the knee joint like a drawer; a normal knee does not slide in this way. There are other physical manipulations of the knee that can be done to aid in the diagnosis of ligament injuries.
• X-rays may be taken to look for excessive fluid build-up in the joint, signs of arthritis or any other problems that may be affecting the knee.

Is there anything that can be done to fix an ACL injury?

It is unusual for lameness to resolve without surgery, especially in large breeds. We use one of two surgical procedures to correct this problem:

• TPLO surgery
• Extracapsular

Tibial Plateau Leveling Osteotomy (TPLO)
Wagon Model Used to Explain Instability of the Knee Joint

• The tibial plateau of a dog’s knee (stifle) is sloped.
• Understanding the importance of the tibial slope when the cranial cruciate ligament is torn is somewhat difficult. We therefore present a model of a wagon on a hill, which is tied to a fence post.
• The slope of the hill represents the tibial plateau, the wagon represents the femur bone, and the cable represents the cranial cruciate ligament.
• If the cable is torn, the wagon will roll down the hill (see fig below). Likewise, when cranial cruciate ligament is torn the femur bone will slide down the slope of the tibial plateau.
• When surface that the wagon is placed on is level and weight is put in the wagon, it does not to roll backward (see fig below).
• In the dog, the tibial plateau leveling osteotomy levels the slope of the tibial plateau so that the femur no longer slides down the plateau. Thus a dynamically stable joint is created even when no cruciate ligament is present.

 

TPLO Surgery

TPLO is a type of knee surgery designed for pets who have injured their ACL (anterior cruciate ligament). The bone of the tibia is cut and then rotated to an angle that prevents the bones of the knee joint from slipping. Bone plates are screwed in place to hold the bone while it heals. During surgery, the knee joint is inspected, and damaged meniscus and bone spurs are removed via a small incision into the joint or arthroscopically. The cruciate ligament remnants may be debrided depending on the degree of damage.

• Up to 90% of patients become fully weight-bearing (normal or near normal function) after TPLO surgery.

How does TPLO compare to other techniques?

• Slower progression of degenerative joint disease as compared to other methods of repair.
• Better range of motion of the joint.
• Return to athletic or working activity (no lameness after heavy activity in most patients).

What are the risks of TPLO surgery?

• Any time a surgery is performed, there is always the possibility of anesthesia complications, but these are minimized by our high quality surgical facility.
• Difficulty restricting activity after surgery (especially in the first 2 months) (link to post rehab. Info) which can cause poor healing due to straining of the patellar ligament, breakage of plates or screws, or loosening of the screws.
• Poor healing of the bone can also be caused by steroid use (usually for allergies) or some illnesses such as diabetes.
• Fracture of tibial plateau or shifting of the position of the bone (from falling or too much activity) which can require additional surgery.
• Infection at the surgery site, (minimized by sterile surgical techniques, antibiotic use, and prevention of licking of the incision after surgery).
• If meniscal cartilage was not damaged at the time of surgery, it may become damaged at a later date requiring a second surgery.
• Improvement may be reduced if your pet has arthritis or advanced degenerative joint disease before surgery.
• Improvement may be reduced if your pet had a previous surgery of an alternate technique on the knee.

Arthritis and ACL Injury

• Unfortunately we cannot stop or reverse the arthritis and degeneration of the joint, but surgery can help to slow its progression.
• If your pet has arthritis in any joint, you may notice stiffness in the morning, lameness after heavy exercise or during weather changes.
• We recommend that you help your pet by keeping them at a healthy weight, maintaining a regular amount of mild exercise, and giving a high quality glucosamine and chondroitin product.

Home-care Instructions for TPLO ACL Repair

1. The patient can be inside, on carpeted surfaces, under your direct supervision. He/She can wander around the room at a slow walk as long as it is not constant. Running, jumping, bounding, playing, etc., are not allowed. Follow the Extracapsular rehabilitation reference sheet below.
2. Please follow the instructions described in the Post Surgical Physical Therapy handout.
3. Please use the provided E-collar to prevent licking or chewing of the incision. Licking or chewing can cause infection or remove staples/sutures. Check the incision twice daily for any signs of redness swelling or discharge and call the hospital if any occur. The skin staples or stitches will be removed at the 14-day recheck.
4. Medications have been dispensed to treat pain and help prevent post-operative infection. Follow the directions on the medication label. Discontinue the medication if you notice vomiting, refusal to eat, or diarrhea. You pet should also be placed on a joint support medication containing glucosamine and chondroitin. Please ask our staff about the amount to administer.
5. During exercise restriction, the patient’s food intake needs to be reduced to help prevent weight gain. Most dogs will maintain their current weight if their food intake is cut in half. Water consumption should remain normal.
6. The patient must be on a leash at all times when outside for fresh air and going to the bathroom. If he/she has to cross slick floors or uneven ground, you may need to use a “belly-band” in case of slips or stumbles. The “belly-band” is not used for support but rather as a safety net to protect. He/she is not allowed to be off lead when outside or to go for an actual walk.
7. When not under your direct supervision, the patient is to be confined in a small room or crate. If your pet is jumping or bouncing in their confined area, he/she is being too active. Tranquilizers may be required to help alleviate any anxiety or to control activity.
8. Playing with other animals is not allowed during confinement. If there are other pets in your household, you will need to keep them separated.
9. One of the most difficult aspects of confinement is that the animals will frequently feel better long before they are healed. At this point your pet will start being more careless of the operated limb and is then more likely to be overactive and cause an injury. You must adhere strictly to the confinement guidelines and not allow more activity than advised.
10. If at any time during your pet’s recovery and healing he/she does anything that causes him/her to cry out or give a sharp yelp, contact us as soon as possible.
11. Following surgery your pet should always maintain at current level of function, or improve. If at any time during recovery and healing your pet has a set back or decrease in function, contact us.
12. It is imperative that you inform us at once if your pet does something that is potentially harmful to the surgery. If something which jeopardizes the outcome of surgery has occurred, it is usually less difficult to correct if it is caught right away, which leads to a better outcome.

Recheck appointments are necessary at the following times:

1. 12-14 days for staple removal.
2. 6 weeks for limb usage evaluation & x-ray to assess bony healing.
3. 11-12 weeks for x-ray determination of the final extent of healing.

Physical Therapy for TPLO/ACL Repair

What are the benefits of physical therapy?

Benefits include:

• Increased blood flow to the affected area.
• Prevention of joint contraction
• Prevention or decrease in muscle atrophy
• Faster return of use of the affected limb.

What does physical therapy involve?

We recommend a combination of actions as follows:

1. Cold packs will minimize post-operative swelling and pain. Never apply the cold pack directly to the skin as it could result in cell damage. For the first 72 hours after surgery, the cold pack should be wrapped in a towel and then applied to the area 2-3 times a day for 5 to 10 minutes each time.
2. Moist heat application will help increase blood flow to the area and relax tense muscles. We recommend using a clean washcloth moistened with warm water (but not dripping wet) starting 72 hours after surgery, heat should be applied 2-3 times a day for a period of 10 to 20 minutes each time.
3. Massage will improve blood and lymphatic flow to the area, which increases available nutrients to an area and promotes waste products and fluid removal. Massage also aids muscle relaxation. The muscles are grasped between the thumb and index finger and gently elevated. The tissues are then compressed alternately between the fingers of one hand and the heel of the other hand. Massage should be firm. Perform for 5 to 10 minutes every day.
4. Passive Range of Motion (PROM) is very important in the prevention of tissue adhesions, promotion of normal joint movement, enhancement of blood and lymphatic flow, and prevention of muscle and joint contracture. Usually, this mode of therapy may be started after sutures are removed. Hands-on instruction by one of our staff members will be given to you before PROM therapy is attempted at home.
5. Exercise. Specific instructions regarding exercise will be covered on your pet’s take home instructions, depending on the type of surgery they had. It is very important to follow these instructions regarding restricted activity to ensure the success of the surgery.

TPLO Rehabilitation Protocol

The first eight weeks are critical to bone healing. Therefore, activity must be kept to a minimum and under strict control to avoid overstressing the bone and reducing stress on the other leg. No running, jumping, sprinting, or ascending/descending stairs is allowed during this period.

Short, leash walks are encouraged during the first eight weeks. This activity will increase muscle stimulation and improve range of motion. Walks are to be done on a short leash and at a very slow pace. Use of extended leads is discouraged.

At one week from surgery:

• Begin with 5-10 minute walks twice daily.
• Flex and extend the knee 10-20 times twice daily for 2 weeks.

At two weeks from surgery:

• Leash walks may be increased to 15 minutes twice daily.
• Continue flexing and extending the knee.

At four weeks from surgery:

• Leash walks may be increased to 20-30 minutes twice daily.

At eight weeks and a follow-up x-ray that demonstrates sufficient bone healing, you may increase your pet’s activity:

• He/she may now begin to go up and down stairs slowly.
• No off leash activity is allowed until the bone has completely healed which is normally evident on the x-ray at twelve weeks.

At twelve weeks from surgery:

• Your pet may start a swimming program one-three times per week.

The basic rehabilitation theme is a slow, gradual return to activity. The thigh muscles will still be weak even after the bone has healed. It often takes 3-6 months after surgery for the muscles to regain their pre-injury strength.

Frequently Asked Questions About TPLO

Does my pet have to spend the night in the hospital?

Orthopedic surgery patients are kept overnight for several reasons. Epidural anesthesia is given to keep your pet comfortable, but makes them unable to walk without assistance. Your pet will also continue to receive IV antibiotics and pain medication.

What can I expect after surgery?

• 24 hours after surgery — about 50% of dogs will be toe touching when walking.
• 5 days post op — most patients will be bearing some weight on the limb.
• 2 weeks post op — a moderate of amount of weight bearing is expected.
• 6-8 weeks — mild lameness may be present. X-rays are taken to monitor bone healing.
• 10 weeks — lameness is usually complete gone.
• 12 weeks — bone is healed. X-rays are taken to verify.
• Partial tear patients tend to recover more quickly.

Can a TPLO be performed on an animal when an older technique has failed?

Improvement is expected but may not be as dramatic on a knee that has had a previous surgery of an alternate technique.

Will my dog experience pain in the postoperative period?

We take pain control very seriously. Your pet will receive pain medication before surgery, epidural anesthesia during the procedure and continue on IV pain medication throughout the evening of surgery. Pain medication will be sent home as well.

How long does it take for healing?

Patients follow specific post-operative physical therapy restricting activity to give the bone time to heal. Controlled exercise is usually started in 6-12 weeks. 4 months after surgery most exercise restrictions are lifted. By 6 months, working, hunting and agility dogs are cleared for full activity.