Tibial Plateau Leveling Osteotomy

  • 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, butsome 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:

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 experienced and skilledstaff.
  • Difficulty restricting activity after surgery (especially in the first 2 months)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 ahealthy weight, maintaining a regular amount of mild exercise, and giving ahigh quality glucosamine and chondroitin product.

Post-Operative Instructions for TPLO ACL Repair

For eight to twelve weeks following surgery, a strict confinement regimen is required. Please follow these instructions closely. If you have any problems or questions not answered here then please call us at 761-7063.

  1. Your pet needs to be kept inside on carpeted surfaces. He/She can wander around a small room at a slow walk as long as it is not constant. Running, jumping, bounding, playing, etc., are not allowed.
  2. Bruising and swelling is expected at and below the incision over the next several days. He/She will likely be reluctant to use the operated leg for the next 7 or so days.
  3. He/She must be on a leash at all times when outside for fresh air and going to the bathroom. The "sling" is to be used for support for approximately the first two weeks after surgery.
  4. When not under your direct supervision, your pet is to be confined in a small room or crate with no access to furniture (elevated beds, couches, etc...)

General Information:

  1. Playing with other animals is not allowed during confinement. If there are other pets in your household, you will need to keep them separated.
  2. During confinement, your pet's food intake needs to be reduced to help prevent weight gain. For most dogs, a 10-15% reduction in food intake is needed during the recovery process. Water consumption should remain normal.
  3. The first two weeks following surgery you will need to monitor your pet's incisions. Licking or chewing can cause infection or sutures to loosen. If you notice that he/she has started licking, you will need to take steps to discourage him/her from doing so by utilizing the e-collar provided.
  4. It takes a minimum of eight to 10 weeks for bones to heal.
  5. 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 injure him/her's self. Until the bone is healed, you must adhere strictly to the confinement guidelines and not allow your pet to do more.
  6. Sedatives (acepromazine) may be required to help alleviate your pet's anxiety or control hyperactivity.
  7. If at any time during your pet's recovery and healing, if he/she does anything that causes him/her to cry out or give a sharp yelp, contact us as soon as possible.
  8. Medications have been dispensed to treat pain and help prevent post-operative infection. Follow the directions on the medication label. Discontinue the medication if your pet vomits, refuses to eat or experiences diarrhea. He/she should also be placed on a joint support medication containing glucosamine and chondroitin (Cosequin ). Please ask our staff about the amount your pet should take.
  9. Your pet may not defecate for several days after the surgery. This is due to the pain medication that was administered. If he/she does not defecate within three days of being home or there is straining to defecate, please notify us.
  10. Recheck appointments are necessary at the following times.
  1. 12-14 days for staple removal.
  2. 6 weeks for limb usage and x-ray evaluation.
  3. 11-12 weeks for x-ray evaluation of bony healing.

Please schedule these appointments with our front desk.


Physical Therapy for TPLO/ACL Repair

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


We recommend the following methods of physical therapy for your pet. Please ask one of the staff members to demonstrate any technique you are not familiar with. Do not hesitate to call us with any questions.

  1. Cold Packs - apply during the first 72 hours after surgery; for approximately 3-5 minutes or as tolerated; to minimize post-operative swelling and pain. Never apply the cold pack directly to the skin as it could result in tissue damage. It is recommended that the cold pack (frozen bag of peas or corn) be wrapped in a towel and then applied to the area two to three times a day.
  2. Heat application - Apply moist heat to the incision area beginning on day 4 after surgery. This will help increase blood flow to the area and relax tense muscles. Heat application should be applied 2 to 3 times a day for a period of 3-5 minutes. We recommend using a warm washcloth as the heat source. Continue warm compresses for 3 days.
  3. Massage - the main objective of massage is to improve blood and lymphatic flow to the area, thereby increasing available nutrients to an area and promoting removal of waste products and fluid. Massage also aids muscle relaxation. With massage 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 enough to cause muscle contraction but gentle enough to avoid causing pain. Begin massaging the lowest part of the leg first and work toward the top of the leg. Massage should be performed twice daily for 5 minutes. This may begin 10 days after surgery.
  4. Benefits of physical therapy include:

    Video provided by:
    Dennis Caywood DVM, MS, DACVS, CCRT
    Senior Veterinary Specialist- Surgery/Rehabilitation

    Passive Range Of Motion (PROM). This is very important in the prevention of tissue adhesions, promotion of normal joint dynamics, enhancement of blood and lymphatic flow, and in preventing muscle and joint contracture. Range of motion exercises can begin after the staples/sutures are removed (12-14 days). Hands on instruction by one of our staff members will be provided 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. 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 joint. 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. Walks may begin 10 days after surgery.

At 10 days from surgery, begin with 5 minute walks twice daily. At two weeks, this may be increased to 10 minute walks and at three weeks, 15-20 minutes twice daily.

After eight weeks and a follow-up x-ray that demonstrates sufficient bone healing, you may increase your pet's activity. Your pet 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 ten to twelve weeks.

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.

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 takepain controlvery 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 followspecific post-operative physical therapyrestricting 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.