Extracapsular Surgery
Anatomy of the Knee
Anterior (Cranial) Cruciate Ligament Rupture
Extracapsular Surgery
Extracapsular Homecare Instructions
Physical Therapy
Extracapsular Rehabilitation
Extracapsular Repair FAQ
Click images above to enlarge
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 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:

Extracapsular Repair
Extracapsular Repair Click images above to enlarge
Extracapsular Surgery
- The knee joint is first inspected via a small incision (arthrotomy) or insertion of a camera (arthroscopy). The torn remnants
of the ACL are removed and the meniscal (diagram) structures are examined. If the meniscus is torn, the damaged portion is removed.
- A strong, non-absorbable suture (nylon band) is passed around a small bone on the back of the knee and then placed through a small
hole made in the front of the tibia bone. The suture is then tightened which serves to prevent drawer motion, effectively taking over the job of the
torn cruciate ligament.
- Over time, scar tissue will form around the suture which helps to stabilize the joint.
- This technique is most commonly used in small dogs and cats.
- About 85% of patients show a significant improvement after surgery and are able to resume pre-injury activities.
Risks and Complications
- Anesthesia complications can occur, but these are minimized by our high quality surgical facility.
- The nylon band can break or loosen from its attachment behind the knee. This most often occurs when pets are too active during the
early healing period (4-6 weeks from surgery).
- Infection at the surgical site. This is minimized by proper sterile technique, peri-operative antibiotic usage, and prevention
of licking of the incision.
- If meniscal cartilage was not damaged at the time of surgery, there is a small chance that it may become damaged at a later date
requiring a second surgery.
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 Extracapsular ACL Repair
- 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.
- Please follow the instructions described in the Post Surgical Physical Therapy handout.
- 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.
- 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.
- 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.
- 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.
- 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.
- Playing with other animals is not allowed during confinement. If there are other pets in your household, you will need to keep them separated.
- 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.
- 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.
- 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.
- 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. 4 weeks for limb usage evaluation.
3. 6 weeks for limb usage evaluation and determination of the final extent of healing.

Physical Therapy for Extracapsular 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:
- 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.
- 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 - starting 72 hours after surgery,
heat should be applied 2-3 times a day for a period of 10 to 20 minutes each time.
- 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.
- 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.
- 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.
Extracapsular Surgery Rehabilitation Protocol
Short, leash walks are encouraged during the first six 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.
Week One:
- Begin with 5-10 minute walks three times daily, followed by an ice-pack (package of frozen peas wrapped in a towel) on knee
for 5-10 minutes.
- Massage the thight muscles for 5-10 minutes daily.
- Flex and extend the knee 10-20 times twice daily.
Weeks Two and Three:
- Increase walks to 10-20 minutes three times daily, followed by an ice-pack (package of frozen peas wrapped in a towel) on knee
for 5-10 minutes if swelling is still present.
- Continue massage the thight muscles for 5-10 minutes daily.
- Flex and extend the knee 10-20 times twice daily.
Weeks Four and Five:
- Leash walks may be increased to 20-30 minutes two to three times daily. While walking, gently nudge your dog sideways.
- Sit/stand 10 repetitions three times daily.
- Figure 8 walks or circling to the left and right 10 times daily.
- If your dog is doing well, “dance” with him/her. Hold up the front legs to encourage walking on the hind legs.
- If your dog is not putting weight on the operated leg, the rehabilitation specialist will give you suggestions.
Weeks Six through Eight:
- Leash walks 30-40 minutes two to three times daily, including inclines, hills, and ramps.
- He/she may now begin to go up and down stairs slowly.
- Tug-of-war.
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 Extracapsular Repairs
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 most dogs will be non-weight bearing to toe touching when walking.
- 5 to 7 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.
- Partial tear patients tend to recover more quickly.
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.

To Resources page
|